build(deps): bump astral-sh/setup-uv from 5 to 6

Bumps [astral-sh/setup-uv](https://github.com/astral-sh/setup-uv) from 5 to 6.
- [Release notes](https://github.com/astral-sh/setup-uv/releases)
- [Commits](https://github.com/astral-sh/setup-uv/compare/v5...v6)

---
updated-dependencies:
- dependency-name: astral-sh/setup-uv
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.envrc

@@ -0,0 +1 @@
+use flake .

.github/dependabot.yml

@@ -0,0 +1,13 @@
+version: 2
+enable-beta-ecosystems: true
+updates:
+- package-ecosystem: uv
+  directory: "/"
+  schedule:
+    interval: daily
+  open-pull-requests-limit: 10
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: daily
+  open-pull-requests-limit: 10

.github/workflows/codeql.yml

@@ -0,0 +1,70 @@
+# For most projects, this workflow file will not need changing; you simply need
+# to commit it to your repository.
+#
+# You may wish to alter this file to override the set of languages analyzed,
+# or to provide custom queries or build logic.
+#
+# ******** NOTE ********
+# We have attempted to detect the languages in your repository. Please check
+# the `language` matrix defined below to confirm you have the correct set of
+# supported CodeQL languages.
+#
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [ master ]
+  schedule:
+    - cron: '31 21 * * 3'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'python' ]
+        # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python', 'ruby' ]
+        # Learn more about CodeQL language support at https://git.io/codeql-language-support
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v3
+      with:
+        languages: ${{ matrix.language }}
+        # If you wish to specify custom queries, you can do so here or in a config file.
+        # By default, queries listed here will override any specified in a config file.
+        # Prefix the list here with "+" to use these queries and those in the config file.
+        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v3
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v3

.github/workflows/pythonpackage.yml

@@ -0,0 +1,38 @@
+# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: Python package
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+  workflow_dispatch: {}
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        poetry-version: ["main"]
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install uv
+      uses: astral-sh/setup-uv@v6
+      with:
+        version: "0.4.30"
+        enable-cache: true
+        cache-dependency-glob: "uv.lock"
+    - name: Install the project
+      run: uv sync --all-extras --dev
+    - name: Lint with flake8
+      run: uv run flake8 sshuttle tests --count --show-source --statistics
+    - name: Run the automated tests
+      run: uv run pytest -v

.github/workflows/release-please.yml

@@ -0,0 +1,66 @@
+on:
+  push:
+    branches:
+      - master
+
+name: release-please
+
+jobs:
+
+  release-please:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    outputs:
+      release_created: ${{ steps.release.outputs.release_created }}
+      tag_name: ${{ steps.release.outputs.tag_name }}
+    steps:
+      - uses: googleapis/release-please-action@v4
+        id: release
+        with:
+          token: ${{ secrets.MY_RELEASE_PLEASE_TOKEN }}
+          release-type: python
+
+  build-pypi:
+    name: Build for pypi
+    needs: [release-please]
+    if: ${{ needs.release-please.outputs.release_created == 'true' }}
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python 3.12
+      uses: actions/setup-python@v5
+      with:
+        python-version: 3.12
+    - name: Install uv
+      uses: astral-sh/setup-uv@v6
+      with:
+        version: "0.4.30"
+        enable-cache: true
+        cache-dependency-glob: "uv.lock"
+    - name: Build project
+      run: uv build
+    - name: Store the distribution packages
+      uses: actions/upload-artifact@v4
+      with:
+        name: python-package-distributions
+        path: dist/
+
+  upload-pypi:
+    name: Upload to pypi
+    needs: [build-pypi]
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/sshuttle
+    permissions:
+      id-token: write
+    steps:
+    - name: Download all the dists
+      uses: actions/download-artifact@v4
+      with:
+        name: python-package-distributions
+        path: dist/
+    - name: Publish package distributions to PyPI
+      uses: pypa/gh-action-pypi-publish@release/v1

.gitignore

@@ -1,3 +1,20 @@
+/tmp/
+/.coverage
+/.cache/
+/.eggs/
+/.tox/
+/build/
+/dist/
+/sshuttle.egg-info/
+/docs/_build/
 *.pyc
 *~
 *.8
+/.do_built
+/.do_built.dir
+/.redo
+/.pytest_cache/
+/.python-version
+/.direnv/
+/result
+/.vscode/

.prospector.yml

@@ -0,0 +1,24 @@
+strictness: medium
+
+pylint:
+  disable:
+    - too-many-statements
+    - too-many-locals
+    - too-many-function-args
+    - too-many-arguments
+    - too-many-branches
+    - bare-except
+    - protected-access
+    - no-else-return
+    - unused-argument
+    - method-hidden
+    - arguments-differ
+    - wrong-import-position
+    - raising-bad-type
+
+pep8:
+  options:
+    max-line-length: 79
+
+mccabe:
+  run: false

.readthedocs.yaml

@@ -0,0 +1,13 @@
+version: 2
+
+build:
+  os: ubuntu-20.04
+  tools:
+    python: "3.10"
+  jobs:
+    post_install:
+      - pip install uv
+      - UV_PROJECT_ENVIRONMENT=$READTHEDOCS_VIRTUALENV_PATH uv sync --all-extras --group docs --link-mode=copy
+
+sphinx:
+  configuration: docs/conf.py

.tool-versions

@@ -0,0 +1 @@
+python 3.10.6

CHANGELOG.md

@@ -0,0 +1,54 @@
+# Changelog
+
+## [1.3.1](https://github.com/sshuttle/sshuttle/compare/v1.3.0...v1.3.1) (2025-03-25)
+
+
+### Bug Fixes
+
+* add pycodestyle config ([5942376](https://github.com/sshuttle/sshuttle/commit/5942376090395d0a8dfe38fe012a519268199341))
+* add python lint tools ([ae3c022](https://github.com/sshuttle/sshuttle/commit/ae3c022d1d67de92f1c4712d06eb8ae76c970624))
+* correct bad version number at runtime ([7b66253](https://github.com/sshuttle/sshuttle/commit/7b662536ba92d724ed8f86a32a21282fea66047c))
+* Restore "nft" method ([375810a](https://github.com/sshuttle/sshuttle/commit/375810a9a8910a51db22c9fe4c0658c39b16c9e7))
+
+## [1.3.0](https://github.com/sshuttle/sshuttle/compare/v1.2.0...v1.3.0) (2025-02-23)
+
+
+### Features
+
+* switch to a network namespace on Linux ([8a123d9](https://github.com/sshuttle/sshuttle/commit/8a123d9762b84f168a8ca8c75f73e590954e122d))
+
+
+### Bug Fixes
+
+* prevent UnicodeDecodeError parsing iptables rule with comments ([cbe3d1e](https://github.com/sshuttle/sshuttle/commit/cbe3d1e402cac9d3fbc818fe0cb8a87be2e94348))
+* remove temp build hack ([1f5e6ce](https://github.com/sshuttle/sshuttle/commit/1f5e6cea703db33761fb1c3f999b9624cf3bc7ad))
+* support ':' sign in password ([7fa927e](https://github.com/sshuttle/sshuttle/commit/7fa927ef8ceea6b1b2848ca433b8b3e3b63f0509))
+
+
+### Documentation
+
+* replace nix-env with nix-shell ([340ccc7](https://github.com/sshuttle/sshuttle/commit/340ccc705ebd9499f14f799fcef0b5d2a8055fb4))
+* update installation instructions ([a2d405a](https://github.com/sshuttle/sshuttle/commit/a2d405a6a7f9d1a301311a109f8411f2fe8deb37))
+
+## [1.2.0](https://github.com/sshuttle/sshuttle/compare/v1.1.2...v1.2.0) (2025-02-07)
+
+
+### Features
+
+* Add release-please to build workflow ([d910b64](https://github.com/sshuttle/sshuttle/commit/d910b64be77fd7ef2a5f169b780bfda95e67318d))
+
+
+### Bug Fixes
+
+* Add support for Python 3.11 and Python 3.11 ([a3396a4](https://github.com/sshuttle/sshuttle/commit/a3396a443df14d3bafc3d25909d9221aa182b8fc))
+* bad file descriptor error in windows, fix pytest errors ([d4d0fa9](https://github.com/sshuttle/sshuttle/commit/d4d0fa945d50606360aa7c5f026a0f190b026c68))
+* drop Python 3.8 support ([1084c0f](https://github.com/sshuttle/sshuttle/commit/1084c0f2458c1595b00963b3bd54bd667e4cfc9f))
+* ensure poetry works for Python 3.9 ([693ee40](https://github.com/sshuttle/sshuttle/commit/693ee40c485c70f353326eb0e8f721f984850f5c))
+* fix broken workflow_dispatch CI rule ([4b6f7c6](https://github.com/sshuttle/sshuttle/commit/4b6f7c6a656a752552295863092d3b8af0b42b31))
+* Remove more references to legacy Python versions ([339b522](https://github.com/sshuttle/sshuttle/commit/339b5221bc33254329f79f2374f6114be6f30aed))
+* replace requirements.txt files with poetry ([85dc319](https://github.com/sshuttle/sshuttle/commit/85dc3199a332f9f9f0e4c6037c883a8f88dc09ca))
+* replace requirements.txt files with poetry (2) ([d08f78a](https://github.com/sshuttle/sshuttle/commit/d08f78a2d9777951d7e18f6eaebbcdd279d7683a))
+* replace requirements.txt files with poetry (3) ([62da705](https://github.com/sshuttle/sshuttle/commit/62da70510e8a1f93e8b38870fdebdbace965cd8e))
+* replace requirements.txt files with poetry (4) ([9bcedf1](https://github.com/sshuttle/sshuttle/commit/9bcedf19049e5b3a8ae26818299cc518ec03a926))
+* update nix flake to fix problems ([cda60a5](https://github.com/sshuttle/sshuttle/commit/cda60a52331c7102cff892b9b77c8321e276680a))
+* use Python >= 3.10 for docs ([bf29464](https://github.com/sshuttle/sshuttle/commit/bf294643e283cef9fb285d44e307e958686caf46))

CHANGES.rst

@@ -0,0 +1,315 @@
+==========
+Change log
+==========
+Release notes now moved to https://github.com/sshuttle/sshuttle/releases/
+
+These are the old release notes.
+
+
+1.0.5 - 2020-12-29
+------------------
+
+Added
+~~~~~
+* IPv6 support in nft method.
+* Intercept DNS requests sent by systemd-resolved.
+* Set default tmark.
+* Fix python2 server compatibility.
+* Python 3.9 support.
+
+Fixed
+~~~~~
+* Change license text to LGPL-2.1
+* Fix #494 sshuttle caught in infinite select() loop.
+* Include sshuttle version in verbose output.
+* Add psutil as dependency in setup.py
+* When subnets and excludes are specified with hostnames, use all IPs.
+* Update/document client's handling of IPv4 and IPv6.
+* Update sdnotify.py documentation.
+* Allow no remote to work.
+* Make prefixes in verbose output more consistent.
+* Make nat and nft rules consistent; improve rule ordering.
+* Make server and client handle resolv.conf differently.
+* Fix handling OSError in FirewallClient#__init__
+* Refactor automatic method selection.
+
+Removed
+~~~~~~~
+* Drop testing of Python 3.5
+
+
+1.0.4 - 2020-08-24
+------------------
+
+Fixed
+~~~~~
+* Allow Mux() flush/fill to work with python < 3.5
+* Fix parse_hostport to always return string for host.
+* Require -r/--remote parameter.
+* Add missing package in OpenWRT documentation.
+* Fix doc about --listen option.
+* README: add Ubuntu.
+* Increase IP4 ttl to 63 hops instead of 42.
+* Fix formatting in installation.rst
+
+
+1.0.3 - 2020-07-12
+------------------
+
+Fixed
+~~~~~
+* Ask setuptools to require Python 3.5 and above.
+* Add missing import.
+* Fix formatting typos in usage docs
+
+
+1.0.2 - 2020-06-18
+------------------
+
+Fixed
+~~~~~
+* Leave use of default port to ssh command.
+* Remove unwanted references to Python 2.7 in docs.
+* Replace usage of deprecated imp.
+* Fix connection with @ sign in username.
+
+
+1.0.1 - 2020-06-05
+------------------
+
+Fixed
+~~~~~
+* Errors in python long_documentation.
+
+
+1.0.0 - 2020-06-05
+------------------
+
+Added
+~~~~~
+* Python 3.8 support.
+* sshpass support.
+* Auto sudoers file (#269).
+* option for latency control buffer size.
+* Docs: FreeBSD'.
+* Docs: Nix'.
+* Docs: openwrt'.
+* Docs: install instructions for Fedora'.
+* Docs: install instructions for Arch Linux'.
+* Docs: 'My VPN broke and need a solution fast'.
+
+Removed
+~~~~~~~
+* Python 2.6 support.
+* Python 2.7 support.
+
+Fixed
+~~~~~
+* Remove debug message for getpeername failure.
+* Fix crash triggered by port scans closing socket.
+* Added "Running as a service" to docs.
+* Systemd integration.
+* Trap UnicodeError to handle cases where hostnames returned by DNS are invalid.
+* Formatting error in CHANGES.rst
+* Various errors in documentation.
+* Nftables based method.
+* Make hostwatch locale-independent (#379).
+* Add tproxy udp port mark filter that was missed in #144, fixes #367.
+* Capturing of local DNS servers.
+* Crashing on ECONNABORTED.
+* Size of pf_rule, which grew in OpenBSD 6.4.
+* Use prompt for sudo, not needed for doas.
+* Arch linux installation instructions.
+* tests for existing PR-312 (#337).
+* Hyphen in hostname.
+* Assembler import (#319).
+
+
+0.78.5 - 2019-01-28
+-------------------
+
+Added
+~~~~~
+* doas support as replacement for sudo on OpenBSD.
+* Added ChromeOS section to documentation (#262)
+* Add --no-sudo-pythonpath option
+
+Fixed
+~~~~~
+* Fix forwarding to a single port.
+* Various updates to documentation.
+* Don't crash if we can't look up peername
+* Fix missing string formatting argument
+* Moved sshuttle/tests into tests.
+* Updated bandit config.
+* Replace path /dev/null by os.devnull.
+* Added coverage report to tests.
+* Fixes support for OpenBSD (6.1+) (#282).
+* Close stdin, stdout, and stderr when using syslog or forking to daemon (#283).
+* Changes pf exclusion rules precedence.
+* Fix deadlock with iptables with large ruleset.
+* docs: document --ns-hosts --to-ns and update --dns.
+* Use subprocess.check_output instead of run.
+* Fix potential deadlock condition in nft_get_handle.
+* auto-nets: retrieve routes only if using auto-nets.
+
+
+0.78.4 - 2018-04-02
+-------------------
+
+Added
+~~~~~
+* Add homebrew instructions.
+* Route traffic by linux user.
+* Add nat-like method using nftables instead of iptables.
+
+Changed
+~~~~~~~
+* Talk to custom DNS server on pod, instead of the ones in /etc/resolv.conf.
+* Add new option for overriding destination DNS server.
+* Changed subnet parsing. Previously 10/8 become 10.0.0.0/8.  Now it gets
+  parsed as 0.0.0.10/8.
+* Make hostwatch find both fqdn and hostname.
+* Use versions of python3 greater than 3.5 when available (e.g. 3.6).
+
+Removed
+~~~~~~~
+* Remove Python 2.6 from automatic tests.
+
+Fixed
+~~~~~
+* Fix case where there is no --dns.
+* [pf] Avoid port forwarding from loopback address.
+* Use getaddrinfo to obtain a correct sockaddr.
+* Skip empty lines on incoming routes data.
+* Just skip empty lines of routes data instead of stopping processing.
+* [pf] Load pf kernel module when enabling pf.
+* [pf] Test double restore (ipv4, ipv6) disables only once; test kldload.
+* Fixes UDP and DNS proxies binding to the same socket address.
+* Mock socket bind to avoid depending on local IPs being available in test box.
+* Fix no value passed for argument auto_hosts in hw_main call.
+* Fixed incorrect license information in setup.py.
+* Preserve peer and port properly.
+* Make --to-dns and --ns-host work well together.
+* Remove test that fails under OSX.
+* Specify pip requirements for tests.
+* Use flake8 to find Python syntax errors or undefined names.
+* Fix compatibility with the sudoers file.
+* Stop using SO_REUSEADDR on sockets.
+* Declare 'verbosity' as global variable to placate linters.
+* Adds 'cd sshuttle' after 'git' to README and docs.
+* Documentation for loading options from configuration file.
+* Load options from a file.
+* Fix firewall.py.
+* Move sdnotify after setting up firewall rules.
+* Fix tests on Macos.
+
+
+0.78.3 - 2017-07-09
+-------------------
+The "I should have done a git pull" first release.
+
+Fixed
+~~~~~
+* Order first by port range and only then by swidth
+
+
+0.78.2 - 2017-07-09
+-------------------
+
+Added
+~~~~~
+* Adds support for tunneling specific port ranges (#144).
+* Add support for iproute2.
+* Allow remote hosts with colons in the username.
+* Re-introduce ipfw support for sshuttle on FreeBSD with support for --DNS option as well.
+* Add support for PfSense.
+* Tests and documentation for systemd integration.
+* Allow subnets to be given only by file (-s).
+
+Fixed
+~~~~~
+* Work around non tabular headers in BSD netstat.
+* Fix UDP and DNS support on Python 2.7 with tproxy method.
+* Fixed tests after adding support for iproute2.
+* Small refactoring of netstat/iproute parsing.
+* Set started_by_sshuttle False after disabling pf.
+* Fix punctuation and explain Type=notify.
+* Move pytest-runner to tests_require.
+* Fix warning: closed channel got=STOP_SENDING.
+* Support sdnotify for better systemd integration.
+* Fix #117 to allow for no subnets via file (-s).
+* Fix argument splitting for multi-word arguments.
+* requirements.rst: Fix mistakes.
+* Fix typo, space not required here.
+* Update installation instructions.
+* Support using run from different directory.
+* Ensure we update sshuttle/version.py in run.
+* Don't print python version in run.
+* Add CWD to PYTHONPATH in run.
+
+
+0.78.1 - 2016-08-06
+-------------------
+* Fix readthedocs versioning.
+* Don't crash on ENETUNREACH.
+* Various bug fixes.
+* Improvements to BSD and OSX support.
+
+
+0.78.0 - 2016-04-08
+-------------------
+
+* Don't force IPv6 if IPv6 nameservers supplied. Fixes #74.
+* Call /bin/sh as users shell may not be POSIX compliant. Fixes #77.
+* Use argparse for command line processing. Fixes #75.
+* Remove useless --server option.
+* Support multiple -s (subnet) options. Fixes #86.
+* Make server parts work with old versions of Python. Fixes #81.
+
+
+0.77.2 - 2016-03-07
+-------------------
+
+* Accidentally switched LGPL2 license with GPL2 license in 0.77.1 - now fixed.
+
+
+0.77.1 - 2016-03-07
+-------------------
+
+* Use semantic versioning. http://semver.org/
+* Update GPL 2 license text.
+* New release to fix PyPI.
+
+
+0.77 - 2016-03-03
+-----------------
+
+* Various bug fixes.
+* Fix Documentation.
+* Add fix for MacOS X issue.
+* Add support for OpenBSD.
+
+
+0.76 - 2016-01-17
+-----------------
+
+* Add option to disable IPv6 support.
+* Update documentation.
+* Move documentation, including man page, to Sphinx.
+* Use setuptools-scm for automatic versioning.
+
+
+0.75 - 2016-01-12
+-----------------
+
+* Revert change that broke sshuttle entry point.
+
+
+0.74 - 2016-01-10
+-----------------
+
+* Add CHANGES.rst file.
+* Numerous bug fixes.
+* Python 3.5 fixes.
+* PF fixes, especially for BSD.

LICENSE

@@ -1,112 +1,125 @@
-		  GNU LIBRARY GENERAL PUBLIC LICENSE
-		       Version 2, June 1991
+                  GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 2.1, February 1999
 
- Copyright (C) 1991 Free Software Foundation, Inc.
-                    675 Mass Ave, Cambridge, MA 02139, USA
+ Copyright (C) 1991, 1999 Free Software Foundation, Inc.
+ 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  Everyone is permitted to copy and distribute verbatim copies
  of this license document, but changing it is not allowed.
 
-[This is the first released version of the library GPL.  It is
- numbered 2 because it goes with version 2 of the ordinary GPL.]
+[This is the first released version of the Lesser GPL.  It also counts
+ as the successor of the GNU Library Public License, version 2, hence
+ the version number 2.1.]
 
-			    Preamble
+                            Preamble
 
   The licenses for most software are designed to take away your
 freedom to share and change it.  By contrast, the GNU General Public
 Licenses are intended to guarantee your freedom to share and change
 free software--to make sure the software is free for all its users.
 
-  This license, the Library General Public License, applies to some
-specially designated Free Software Foundation software, and to any
-other libraries whose authors decide to use it.  You can use it for
-your libraries, too.
+  This license, the Lesser General Public License, applies to some
+specially designated software packages--typically libraries--of the
+Free Software Foundation and other authors who decide to use it.  You
+can use it too, but we suggest you first think carefully about whether
+this license or the ordinary General Public License is the better
+strategy to use in any particular case, based on the explanations below.
 
-  When we speak of free software, we are referring to freedom, not
-price.  Our General Public Licenses are designed to make sure that you
-have the freedom to distribute copies of free software (and charge for
-this service if you wish), that you receive source code or can get it
-if you want it, that you can change the software or use pieces of it
-in new free programs; and that you know you can do these things.
+  When we speak of free software, we are referring to freedom of use,
+not price.  Our General Public Licenses are designed to make sure that
+you have the freedom to distribute copies of free software (and charge
+for this service if you wish); that you receive source code or can get
+it if you want it; that you can change the software and use pieces of
+it in new free programs; and that you are informed that you can do
+these things.
 
   To protect your rights, we need to make restrictions that forbid
-anyone to deny you these rights or to ask you to surrender the rights.
-These restrictions translate to certain responsibilities for you if
-you distribute copies of the library, or if you modify it.
+distributors to deny you these rights or to ask you to surrender these
+rights.  These restrictions translate to certain responsibilities for
+you if you distribute copies of the library or if you modify it.
 
   For example, if you distribute copies of the library, whether gratis
 or for a fee, you must give the recipients all the rights that we gave
 you.  You must make sure that they, too, receive or can get the source
-code.  If you link a program with the library, you must provide
-complete object files to the recipients so that they can relink them
-with the library, after making changes to the library and recompiling
+code.  If you link other code with the library, you must provide
+complete object files to the recipients, so that they can relink them
+with the library after making changes to the library and recompiling
 it.  And you must show them these terms so they know their rights.
 
-  Our method of protecting your rights has two steps: (1) copyright
-the library, and (2) offer you this license which gives you legal
+  We protect your rights with a two-step method: (1) we copyright the
+library, and (2) we offer you this license, which gives you legal
 permission to copy, distribute and/or modify the library.
 
-  Also, for each distributor's protection, we want to make certain
-that everyone understands that there is no warranty for this free
-library.  If the library is modified by someone else and passed on, we
-want its recipients to know that what they have is not the original
-version, so that any problems introduced by others will not reflect on
-the original authors' reputations.
+  To protect each distributor, we want to make it very clear that
+there is no warranty for the free library.  Also, if the library is
+modified by someone else and passed on, the recipients should know
+that what they have is not the original version, so that the original
+author's reputation will not be affected by problems that might be
+introduced by others.
 
-  Finally, any free program is threatened constantly by software
-patents.  We wish to avoid the danger that companies distributing free
-software will individually obtain patent licenses, thus in effect
-transforming the program into proprietary software.  To prevent this,
-we have made it clear that any patent must be licensed for everyone's
-free use or not licensed at all.
+  Finally, software patents pose a constant threat to the existence of
+any free program.  We wish to make sure that a company cannot
+effectively restrict the users of a free program by obtaining a
+restrictive license from a patent holder.  Therefore, we insist that
+any patent license obtained for a version of the library must be
+consistent with the full freedom of use specified in this license.
 
-  Most GNU software, including some libraries, is covered by the ordinary
-GNU General Public License, which was designed for utility programs.  This
-license, the GNU Library General Public License, applies to certain
-designated libraries.  This license is quite different from the ordinary
-one; be sure to read it in full, and don't assume that anything in it is
-the same as in the ordinary license.
+  Most GNU software, including some libraries, is covered by the
+ordinary GNU General Public License.  This license, the GNU Lesser
+General Public License, applies to certain designated libraries, and
+is quite different from the ordinary General Public License.  We use
+this license for certain libraries in order to permit linking those
+libraries into non-free programs.
 
-  The reason we have a separate public license for some libraries is that
-they blur the distinction we usually make between modifying or adding to a
-program and simply using it.  Linking a program with a library, without
-changing the library, is in some sense simply using the library, and is
-analogous to running a utility program or application program.  However, in
-a textual and legal sense, the linked executable is a combined work, a
-derivative of the original library, and the ordinary General Public License
-treats it as such.
+  When a program is linked with a library, whether statically or using
+a shared library, the combination of the two is legally speaking a
+combined work, a derivative of the original library.  The ordinary
+General Public License therefore permits such linking only if the
+entire combination fits its criteria of freedom.  The Lesser General
+Public License permits more lax criteria for linking other code with
+the library.
 
-  Because of this blurred distinction, using the ordinary General
-Public License for libraries did not effectively promote software
-sharing, because most developers did not use the libraries.  We
-concluded that weaker conditions might promote sharing better.
+  We call this license the "Lesser" General Public License because it
+does Less to protect the user's freedom than the ordinary General
+Public License.  It also provides other free software developers Less
+of an advantage over competing non-free programs.  These disadvantages
+are the reason we use the ordinary General Public License for many
+libraries.  However, the Lesser license provides advantages in certain
+special circumstances.
 
-  However, unrestricted linking of non-free programs would deprive the
-users of those programs of all benefit from the free status of the
-libraries themselves.  This Library General Public License is intended to
-permit developers of non-free programs to use free libraries, while
-preserving your freedom as a user of such programs to change the free
-libraries that are incorporated in them.  (We have not seen how to achieve
-this as regards changes in header files, but we have achieved it as regards
-changes in the actual functions of the Library.)  The hope is that this
-will lead to faster development of free libraries.
+  For example, on rare occasions, there may be a special need to
+encourage the widest possible use of a certain library, so that it becomes
+a de-facto standard.  To achieve this, non-free programs must be
+allowed to use the library.  A more frequent case is that a free
+library does the same job as widely used non-free libraries.  In this
+case, there is little to gain by limiting the free library to free
+software only, so we use the Lesser General Public License.
+
+  In other cases, permission to use a particular library in non-free
+programs enables a greater number of people to use a large body of
+free software.  For example, permission to use the GNU C Library in
+non-free programs enables many more people to use the whole GNU
+operating system, as well as its variant, the GNU/Linux operating
+system.
+
+  Although the Lesser General Public License is Less protective of the
+users' freedom, it does ensure that the user of a program that is
+linked with the Library has the freedom and the wherewithal to run
+that program using a modified version of the Library.
 
   The precise terms and conditions for copying, distribution and
 modification follow.  Pay close attention to the difference between a
 "work based on the library" and a "work that uses the library".  The
-former contains code derived from the library, while the latter only
-works together with the library.
-
-  Note that it is possible for a library to be covered by the ordinary
-General Public License rather than by this special one.
+former contains code derived from the library, whereas the latter must
+be combined with the library in order to run.
 
-		  GNU LIBRARY GENERAL PUBLIC LICENSE
+                  GNU LESSER GENERAL PUBLIC LICENSE
    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
 
-  0. This License Agreement applies to any software library which
-contains a notice placed by the copyright holder or other authorized
-party saying it may be distributed under the terms of this Library
-General Public License (also called "this License").  Each licensee is
-addressed as "you".
+  0. This License Agreement applies to any software library or other
+program which contains a notice placed by the copyright holder or
+other authorized party saying it may be distributed under the terms of
+this Lesser General Public License (also called "this License").
+Each licensee is addressed as "you".
 
   A "library" means a collection of software functions and/or data
 prepared so as to be conveniently linked with application programs
@@ -133,7 +146,7 @@ such a program is covered only if its contents constitute a work based
 on the Library (independent of the use of the Library in a tool for
 writing it).  Whether that is true depends on what the Library does
 and what the program that uses the Library does.
-  
+
   1. You may copy and distribute verbatim copies of the Library's
 complete source code as you receive it, in any medium, provided that
 you conspicuously and appropriately publish on each copy an
@@ -255,7 +268,7 @@ distribute the object code for the work under the terms of Section 6.
 Any executables containing that work also fall under Section 6,
 whether or not they are linked directly with the Library itself.
 
-  6. As an exception to the Sections above, you may also compile or
+  6. As an exception to the Sections above, you may also combine or
 link a "work that uses the Library" with the Library to produce a
 work containing portions of the Library, and distribute that work
 under terms of your choice, provided that the terms permit
@@ -282,23 +295,31 @@ of these things:
     Library will not necessarily be able to recompile the application
     to use the modified definitions.)
 
-    b) Accompany the work with a written offer, valid for at
+    b) Use a suitable shared library mechanism for linking with the
+    Library.  A suitable mechanism is one that (1) uses at run time a
+    copy of the library already present on the user's computer system,
+    rather than copying library functions into the executable, and (2)
+    will operate properly with a modified version of the library, if
+    the user installs one, as long as the modified version is
+    interface-compatible with the version that the work was made with.
+
+    c) Accompany the work with a written offer, valid for at
     least three years, to give the same user the materials
     specified in Subsection 6a, above, for a charge no more
     than the cost of performing this distribution.
 
-    c) If distribution of the work is made by offering access to copy
+    d) If distribution of the work is made by offering access to copy
     from a designated place, offer equivalent access to copy the above
     specified materials from the same place.
 
-    d) Verify that the user has already received a copy of these
+    e) Verify that the user has already received a copy of these
     materials or that you have already sent this user a copy.
 
   For an executable, the required form of the "work that uses the
 Library" must include any data and utility programs needed for
 reproducing the executable from it.  However, as a special exception,
-the source code distributed need not include anything that is normally
-distributed (in either source or binary form) with the major
+the materials to be distributed need not include anything that is
+normally distributed (in either source or binary form) with the major
 components (compiler, kernel, and so on) of the operating system on
 which the executable runs, unless that component itself accompanies
 the executable.
@@ -347,7 +368,7 @@ Library), the recipient automatically receives a license from the
 original licensor to copy, distribute, link with or modify the Library
 subject to these terms and conditions.  You may not impose any further
 restrictions on the recipients' exercise of the rights granted herein.
-You are not responsible for enforcing compliance by third parties to
+You are not responsible for enforcing compliance by third parties with
 this License.
 
   11. If, as a consequence of a court judgment or allegation of patent
@@ -390,7 +411,7 @@ excluded.  In such case, this License incorporates the limitation as if
 written in the body of this License.
 
   13. The Free Software Foundation may publish revised and/or new
-versions of the Library General Public License from time to time.
+versions of the Lesser General Public License from time to time.
 Such new versions will be similar in spirit to the present version,
 but may differ in detail to address new problems or concerns.
 
@@ -411,7 +432,7 @@ decision will be guided by the two goals of preserving the free status
 of all derivatives of our free software and of promoting the sharing
 and reuse of software generally.
 
-			    NO WARRANTY
+                            NO WARRANTY
 
   15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
 WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
@@ -434,9 +455,9 @@ FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
 SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
 DAMAGES.
 
-		     END OF TERMS AND CONDITIONS
+                     END OF TERMS AND CONDITIONS
 
-     Appendix: How to Apply These Terms to Your New Libraries
+           How to Apply These Terms to Your New Libraries
 
   If you develop a new library, and you want it to be of the greatest
 possible use to the public, we recommend making it free software that
@@ -453,18 +474,18 @@ convey the exclusion of warranty; and each file should have at least the
     Copyright (C) <year>  <name of author>
 
     This library is free software; you can redistribute it and/or
-    modify it under the terms of the GNU Library General Public
+    modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
-    version 2 of the License, or (at your option) any later version.
+    version 2.1 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-    Library General Public License for more details.
+    Lesser General Public License for more details.
 
-    You should have received a copy of the GNU Library General Public
-    License along with this library; if not, write to the Free
-    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+    You should have received a copy of the GNU Lesser General Public
+    License along with this library; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 
 Also add information on how to contact you by electronic and paper mail.
 

MANIFEST.in

@@ -0,0 +1,14 @@
+include *.txt
+include *.rst
+include *.py
+include MANIFEST.in
+include LICENSE
+include run
+include tox.ini
+exclude sshuttle/version.py
+recursive-include docs *.bat
+recursive-include docs *.py
+recursive-include docs *.rst
+recursive-include docs Makefile
+recursive-include sshuttle *.py
+recursive-exclude docs/_build *

Makefile

@@ -1,19 +0,0 @@
-PANDOC:=$(shell \
-	if pandoc </dev/null 2>/dev/null; then \
-		echo pandoc; \
-	else \
-		echo "Warning: pandoc not installed; can't generate manpages." >&2; \
-		echo '@echo Skipping: pandoc'; \
-	fi)
-
-default: all
-
-all: sshuttle.8
-
-sshuttle.8: sshuttle.md
-
-%.8: %.md
-	$(PANDOC) -s -r markdown -w man -o $@ $<
-
-clean:
-	rm -f *~ */*~ .*~ */.*~ *.8 *.tmp */*.tmp *.pyc */*.pyc

README.md

@@ -1,166 +0,0 @@
-sshuttle: where transparent proxy meets VPN meets ssh
-=====================================================
-
-As far as I know, sshuttle is the only program that solves the following
-common case:
-
- - Your client machine (or router) is Linux, FreeBSD, or MacOS.
-
- - You have access to a remote network via ssh.
-
- - You don't necessarily have admin access on the remote network.
-
- - The remote network has no VPN, or only stupid/complex VPN
-    protocols (IPsec, PPTP, etc). Or maybe you <i>are</i> the
-    admin and you just got frustrated with the awful state of
-    VPN tools.
-
- - You don't want to create an ssh port forward for every
-    single host/port on the remote network.
-
- - You hate openssh's port forwarding because it's randomly
-    slow and/or stupid.
- 
- - You can't use openssh's PermitTunnel feature because
-    it's disabled by default on openssh servers; plus it does
-    TCP-over-TCP, which has terrible performance (see below).
-    
-
-Prerequisites
--------------
-
- - sudo, su, or logged in as root on your client machine.
-   (The server doesn't need admin access.)
-   
- - If you use Linux on your client machine:
-   iptables installed on the client, including at
-   least the iptables DNAT, REDIRECT, and ttl modules. 
-   These are installed by default on most Linux distributions. 
-   (The server doesn't need iptables and doesn't need to be
-   Linux.)
-   
- - If you use MacOS or BSD on your client machine:
-   Your kernel needs to be compiled with IPFIREWALL_FORWARD
-   (MacOS has this by default) and you need to have ipfw
-   available. (The server doesn't need to be MacOS or BSD.)
-
-
-This is how you use it:
------------------------
-
- - <tt>git clone git://github.com/apenwarr/sshuttle</tt>
-    on your client machine. You'll need root or sudo
-    access, and python needs to be installed.
-
- - <tt>./sshuttle -r username@sshserver 0.0.0.0/0 -vv</tt>
-
-(You may be prompted for one or more passwords; first, the
-local password to become root using either sudo or su, and
-then the remote ssh password.  Or you might have sudo and ssh set
-up to not require passwords, in which case you won't be
-prompted at all.)
-
-That's it!  Now your local machine can access the remote network as if you
-were right there.  And if your "client" machine is a router, everyone on
-your local network can make connections to your remote network.
-
-You don't need to install sshuttle on the remote server;
-the remote server just needs to have python available. 
-sshuttle will automatically upload and run its source code
-to the remote python interpreter.
-
-This creates a transparent proxy server on your local machine for all IP
-addresses that match 0.0.0.0/0.  (You can use more specific IP addresses if
-you want; use any number of IP addresses or subnets to change which
-addresses get proxied.  Using 0.0.0.0/0 proxies <i>everything</i>, which is
-interesting if you don't trust the people on your local network.)
-
-Any TCP session you initiate to one of the proxied IP addresses will be
-captured by sshuttle and sent over an ssh session to the remote copy of
-sshuttle, which will then regenerate the connection on that end, and funnel
-the data back and forth through ssh.
-
-Fun, right?  A poor man's instant VPN, and you don't even have to have
-admin access on the server.
-
-
-Theory of Operation
--------------------
-
-sshuttle is not exactly a VPN, and not exactly port forwarding.  It's kind
-of both, and kind of neither.
-
-It's like a VPN, since it can forward every port on an entire network, not
-just ports you specify.  Conveniently, it lets you use the "real" IP
-addresses of each host rather than faking port numbers on localhost.
-
-On the other hand, the way it *works* is more like ssh port forwarding than
-a VPN.  Normally, a VPN forwards your data one packet at a time, and
-doesn't care about individual connections; ie. it's "stateless" with respect
-to the traffic.  sshuttle is the opposite of stateless; it tracks every
-single connection.
-
-You could compare sshuttle to something like the old <a
-href="http://en.wikipedia.org/wiki/Slirp">Slirp</a> program, which was a
-userspace TCP/IP implementation that did something similar.  But it
-operated on a packet-by-packet basis on the client side, reassembling the
-packets on the server side.  That worked okay back in the "real live serial
-port" days, because serial ports had predictable latency and buffering.
-
-But you can't safely just forward TCP packets over a TCP session (like ssh),
-because TCP's performance depends fundamentally on packet loss; it
-<i>must</i> experience packet loss in order to know when to slow down!  At
-the same time, the outer TCP session (ssh, in this case) is a reliable
-transport, which means that what you forward through the tunnel <i>never</i>
-experiences packet loss.  The ssh session itself experiences packet loss, of
-course, but TCP fixes it up and ssh (and thus you) never know the
-difference.  But neither does your inner TCP session, and extremely screwy
-performance ensues.
-
-sshuttle assembles the TCP stream locally, multiplexes it statefully over
-an ssh session, and disassembles it back into packets at the other end.  So
-it never ends up doing TCP-over-TCP.  It's just data-over-TCP, which is
-safe.
-
-
-Useless Trivia
---------------
-
-Back in 1998 (12 years ago!  Yikes!), I released the first version of <a
-href="http://alumnit.ca/wiki/?TunnelVisionReadMe">Tunnel Vision</a>, a
-semi-intelligent VPN client for Linux.  Unfortunately, I made two big mistakes: 
-I implemented the key exchange myself (oops), and I ended up doing
-TCP-over-TCP (double oops).  The resulting program worked okay - and people
-used it for years - but the performance was always a bit funny.  And nobody
-ever found any security flaws in my key exchange, either, but that doesn't
-mean anything. :)
-
-The same year, dcoombs and I also released Fast Forward, a proxy server
-supporting transparent proxying.  Among other things, we used it for
-automatically splitting traffic across more than one Internet connection (a
-tool we called "Double Vision").
-
-I was still in university at the time.  A couple years after that, one of my
-professors was working with some graduate students on the technology that
-would eventually become <a href="http://www.slipstream.com/">Slipstream
-Internet Acceleration</a>.  He asked me to do a contract for him to build an
-initial prototype of a transparent proxy server for mobile networks.  The
-idea was similar to sshuttle: if you reassemble and then disassemble the TCP
-packets, you can reduce latency and improve performance vs.  just forwarding
-the packets over a plain VPN or mobile network.  (It's unlikely that any of
-my code has persisted in the Slipstream product today, but the concept is
-still pretty cool.  I'm still horrified that people use plain TCP on
-complex mobile networks with crazily variable latency, for which it was
-never really intended.)
-
-That project I did for Slipstream was what first gave me the idea to merge
-the concepts of Fast Forward, Double Vision, and Tunnel Vision into a single
-program that was the best of all worlds.  And here we are, at last, 10 years
-later.  You're welcome.
-
---
-Avery Pennarun <apenwarr@gmail.com>
-
-Mailing list:
-   Subscribe by sending a message to <sshuttle+subscribe@googlegroups.com>
-   List archives are at: http://groups.google.com/group/sshuttle

README.rst

@@ -0,0 +1,49 @@
+sshuttle: where transparent proxy meets VPN meets ssh
+=====================================================
+
+As far as I know, sshuttle is the only program that solves the following
+common case:
+
+- Your client machine (or router) is Linux, FreeBSD, MacOS or Windows.
+
+- You have access to a remote network via ssh.
+
+- You don't necessarily have admin access on the remote network.
+
+- The remote network has no VPN, or only stupid/complex VPN
+  protocols (IPsec, PPTP, etc). Or maybe you *are* the
+  admin and you just got frustrated with the awful state of
+  VPN tools.
+
+- You don't want to create an ssh port forward for every
+  single host/port on the remote network.
+
+- You hate openssh's port forwarding because it's randomly
+  slow and/or stupid.
+
+- You can't use openssh's PermitTunnel feature because
+  it's disabled by default on openssh servers; plus it does
+  TCP-over-TCP, which has `terrible performance`_.
+
+.. _terrible performance: https://sshuttle.readthedocs.io/en/stable/how-it-works.html
+
+Obtaining sshuttle
+------------------
+
+Please see the documentation_.
+
+.. _Documentation: https://sshuttle.readthedocs.io/en/stable/installation.html
+
+Documentation
+-------------
+The documentation for the stable version is available at:
+https://sshuttle.readthedocs.org/
+
+The documentation for the latest development version is available at:
+https://sshuttle.readthedocs.org/en/latest/
+
+
+Running as a service
+--------------------
+Sshuttle can also be run as a service and configured using a config management system:
+https://medium.com/@mike.reider/using-sshuttle-as-a-service-bec2684a65fe

assembler.py

@@ -1,26 +0,0 @@
-import sys, zlib
-
-z = zlib.decompressobj()
-mainmod = sys.modules[__name__]
-while 1:
-    name = sys.stdin.readline().strip()
-    if name:
-        nbytes = int(sys.stdin.readline())
-        if verbosity >= 2:
-            sys.stderr.write('server: assembling %r (%d bytes)\n'
-                             % (name, nbytes))
-        content = z.decompress(sys.stdin.read(nbytes))
-        exec compile(content, name, "exec")
-
-        # FIXME: this crushes everything into a single module namespace,
-        # then makes each of the module names point at this one. Gross.
-        assert(name.endswith('.py'))
-        modname = name[:-3]
-        mainmod.__dict__[modname] = mainmod
-    else:
-        break
-
-verbose = verbosity
-sys.stderr.flush()
-sys.stdout.flush()
-main()

bandit.yml

@@ -0,0 +1,9 @@
+exclude_dirs:
+  - tests
+skips:
+  - B101
+  - B104
+  - B404
+  - B603
+  - B606
+  - B607

client.py

@@ -1,218 +0,0 @@
-import struct, socket, select, errno, re
-import compat.ssubprocess as ssubprocess
-import helpers, ssnet, ssh
-from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
-from helpers import *
-
-
-def original_dst(sock):
-    try:
-        SO_ORIGINAL_DST = 80
-        SOCKADDR_MIN = 16
-        sockaddr_in = sock.getsockopt(socket.SOL_IP,
-                                      SO_ORIGINAL_DST, SOCKADDR_MIN)
-        (proto, port, a,b,c,d) = struct.unpack('!HHBBBB', sockaddr_in[:8])
-        assert(socket.htons(proto) == socket.AF_INET)
-        ip = '%d.%d.%d.%d' % (a,b,c,d)
-        return (ip,port)
-    except socket.error, e:
-        if e.args[0] == errno.ENOPROTOOPT:
-            return sock.getsockname()
-        raise
-
-
-class FirewallClient:
-    def __init__(self, port, subnets_include, subnets_exclude):
-        self.port = port
-        self.auto_nets = []
-        self.subnets_include = subnets_include
-        self.subnets_exclude = subnets_exclude
-        argvbase = ([sys.argv[0]] +
-                    ['-v'] * (helpers.verbose or 0) +
-                    ['--firewall', str(port)])
-        argv_tries = [
-            ['sudo', '-p', '[local sudo] Password: '] + argvbase,
-            ['su', '-c', ' '.join(argvbase)],
-            argvbase
-        ]
-
-        # we can't use stdin/stdout=subprocess.PIPE here, as we normally would,
-        # because stupid Linux 'su' requires that stdin be attached to a tty.
-        # Instead, attach a *bidirectional* socket to its stdout, and use
-        # that for talking in both directions.
-        (s1,s2) = socket.socketpair()
-        def setup():
-            # run in the child process
-            s2.close()
-        e = None
-        if os.getuid() == 0:
-            argv_tries = argv_tries[-1:]  # last entry only
-        for argv in argv_tries:
-            try:
-                if argv[0] == 'su':
-                    sys.stderr.write('[local su] ')
-                self.p = ssubprocess.Popen(argv, stdout=s1, preexec_fn=setup)
-                e = None
-                break
-            except OSError, e:
-                pass
-        self.argv = argv
-        s1.close()
-        self.pfile = s2.makefile('wb+')
-        if e:
-            log('Spawning firewall manager: %r\n' % self.argv)
-            raise Fatal(e)
-        line = self.pfile.readline()
-        self.check()
-        if line != 'READY\n':
-            raise Fatal('%r expected READY, got %r' % (self.argv, line))
-
-    def check(self):
-        rv = self.p.poll()
-        if rv:
-            raise Fatal('%r returned %d' % (self.argv, rv))
-
-    def start(self):
-        self.pfile.write('ROUTES\n')
-        for (ip,width) in self.subnets_include+self.auto_nets:
-            self.pfile.write('%d,0,%s\n' % (width, ip))
-        for (ip,width) in self.subnets_exclude:
-            self.pfile.write('%d,1,%s\n' % (width, ip))
-        self.pfile.write('GO\n')
-        self.pfile.flush()
-        line = self.pfile.readline()
-        self.check()
-        if line != 'STARTED\n':
-            raise Fatal('%r expected STARTED, got %r' % (self.argv, line))
-
-    def sethostip(self, hostname, ip):
-        assert(not re.search(r'[^-\w]', hostname))
-        assert(not re.search(r'[^0-9.]', ip))
-        self.pfile.write('HOST %s,%s\n' % (hostname, ip))
-        self.pfile.flush()
-
-    def done(self):
-        self.pfile.close()
-        rv = self.p.wait()
-        if rv:
-            raise Fatal('cleanup: %r returned %d' % (self.argv, rv))
-
-
-def _main(listener, fw, ssh_cmd, remotename, python, seed_hosts, auto_nets):
-    handlers = []
-    if helpers.verbose >= 1:
-        helpers.logprefix = 'c : '
-    else:
-        helpers.logprefix = 'client: '
-    debug1('connecting to server...\n')
-    try:
-        (serverproc, serversock) = ssh.connect(ssh_cmd, remotename, python)
-    except socket.error, e:
-        if e.errno == errno.EPIPE:
-            raise Fatal("failed to establish ssh session")
-        else:
-            raise
-    mux = Mux(serversock, serversock)
-    handlers.append(mux)
-
-    expected = 'SSHUTTLE0001'
-    initstring = serversock.recv(len(expected))
-    
-    rv = serverproc.poll()
-    if rv:
-        raise Fatal('server died with error code %d' % rv)
-        
-    if initstring != expected:
-        raise Fatal('expected server init string %r; got %r'
-                        % (expected, initstring))
-    debug1('connected.\n')
-
-    def onroutes(routestr):
-        if auto_nets:
-            for line in routestr.strip().split('\n'):
-                (ip,width) = line.split(',', 1)
-                fw.auto_nets.append((ip,int(width)))
-
-        # we definitely want to do this *after* starting ssh, or we might end
-        # up intercepting the ssh connection!
-        #
-        # Moreover, now that we have the --auto-nets option, we have to wait
-        # for the server to send us that message anyway.  Even if we haven't
-        # set --auto-nets, we might as well wait for the message first, then
-        # ignore its contents.
-        mux.got_routes = None
-        fw.start()
-    mux.got_routes = onroutes
-
-    def onhostlist(hostlist):
-        debug2('got host list: %r\n' % hostlist)
-        for line in hostlist.strip().split():
-            if line:
-                name,ip = line.split(',', 1)
-                fw.sethostip(name, ip)
-    mux.got_host_list = onhostlist
-
-    def onaccept():
-        sock,srcip = listener.accept()
-        dstip = original_dst(sock)
-        debug1('Accept: %r:%r -> %r:%r.\n' % (srcip[0],srcip[1],
-                                           dstip[0],dstip[1]))
-        if dstip == listener.getsockname():
-            debug1("-- ignored: that's my address!\n")
-            sock.close()
-            return
-        chan = mux.next_channel()
-        mux.send(chan, ssnet.CMD_CONNECT, '%s,%s' % dstip)
-        outwrap = MuxWrapper(mux, chan)
-        handlers.append(Proxy(SockWrapper(sock, sock), outwrap))
-    handlers.append(Handler([listener], onaccept))
-
-    if seed_hosts != None:
-        debug1('seed_hosts: %r\n' % seed_hosts)
-        mux.send(0, ssnet.CMD_HOST_REQ, '\n'.join(seed_hosts))
-    
-    while 1:
-        rv = serverproc.poll()
-        if rv:
-            raise Fatal('server died with error code %d' % rv)
-        
-        ssnet.runonce(handlers, mux)
-        mux.callback()
-        mux.check_fullness()
-
-
-def main(listenip, ssh_cmd, remotename, python, seed_hosts, auto_nets,
-         subnets_include, subnets_exclude):
-    debug1('Starting sshuttle proxy.\n')
-    listener = socket.socket()
-    listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-    if listenip[1]:
-        ports = [listenip[1]]
-    else:
-        ports = xrange(12300,9000,-1)
-    last_e = None
-    bound = False
-    debug2('Binding:')
-    for port in ports:
-        debug2(' %d' % port)
-        try:
-            listener.bind((listenip[0], port))
-            bound = True
-            break
-        except socket.error, e:
-            last_e = e
-    debug2('\n')
-    if not bound:
-        assert(last_e)
-        raise last_e
-    listener.listen(10)
-    listenip = listener.getsockname()
-    debug1('Listening on %r.\n' % (listenip,))
-
-    fw = FirewallClient(listenip[1], subnets_include, subnets_exclude)
-    
-    try:
-        return _main(listener, fw, ssh_cmd, remotename,
-                     python, seed_hosts, auto_nets)
-    finally:
-        fw.done()

docs/Makefile

@@ -0,0 +1,177 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+PAPER         =
+BUILDDIR      = _build
+
+# User-friendly check for sphinx-build
+ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
+$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
+endif
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+# the i18n builder cannot share the environment and doctrees with the others
+I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+.PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest gettext
+
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html       to make standalone HTML files"
+	@echo "  dirhtml    to make HTML files named index.html in directories"
+	@echo "  singlehtml to make a single large HTML file"
+	@echo "  pickle     to make pickle files"
+	@echo "  json       to make JSON files"
+	@echo "  htmlhelp   to make HTML files and a HTML help project"
+	@echo "  qthelp     to make HTML files and a qthelp project"
+	@echo "  devhelp    to make HTML files and a Devhelp project"
+	@echo "  epub       to make an epub"
+	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
+	@echo "  latexpdfja to make LaTeX files and run them through platex/dvipdfmx"
+	@echo "  text       to make text files"
+	@echo "  man        to make manual pages"
+	@echo "  texinfo    to make Texinfo files"
+	@echo "  info       to make Texinfo files and run them through makeinfo"
+	@echo "  gettext    to make PO message catalogs"
+	@echo "  changes    to make an overview of all changed/added/deprecated items"
+	@echo "  xml        to make Docutils-native XML files"
+	@echo "  pseudoxml  to make pseudoxml-XML files for display purposes"
+	@echo "  linkcheck  to check all external links for integrity"
+	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
+
+clean:
+	rm -rf $(BUILDDIR)/*
+
+html:
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+singlehtml:
+	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
+	@echo
+	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
+
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/sshuttle.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/sshuttle.qhc"
+
+devhelp:
+	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
+	@echo
+	@echo "Build finished."
+	@echo "To view the help file:"
+	@echo "# mkdir -p $$HOME/.local/share/devhelp/sshuttle"
+	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/sshuttle"
+	@echo "# devhelp"
+
+epub:
+	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
+	@echo
+	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
+
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make' in that directory to run these through (pdf)latex" \
+	      "(use \`make latexpdf' here to do that automatically)."
+
+latexpdf:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through pdflatex..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+latexpdfja:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo "Running LaTeX files through platex and dvipdfmx..."
+	$(MAKE) -C $(BUILDDIR)/latex all-pdf-ja
+	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
+
+text:
+	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
+	@echo
+	@echo "Build finished. The text files are in $(BUILDDIR)/text."
+
+man:
+	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
+	@echo
+	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
+
+texinfo:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo
+	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
+	@echo "Run \`make' in that directory to run these through makeinfo" \
+	      "(use \`make info' here to do that automatically)."
+
+info:
+	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
+	@echo "Running Texinfo files through makeinfo..."
+	make -C $(BUILDDIR)/texinfo info
+	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
+
+gettext:
+	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
+	@echo
+	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
+
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."
+
+xml:
+	$(SPHINXBUILD) -b xml $(ALLSPHINXOPTS) $(BUILDDIR)/xml
+	@echo
+	@echo "Build finished. The XML files are in $(BUILDDIR)/xml."
+
+pseudoxml:
+	$(SPHINXBUILD) -b pseudoxml $(ALLSPHINXOPTS) $(BUILDDIR)/pseudoxml
+	@echo
+	@echo "Build finished. The pseudo-XML files are in $(BUILDDIR)/pseudoxml."

docs/changes.rst

@@ -0,0 +1 @@
+.. include:: ../CHANGES.rst

docs/chromeos.rst

@@ -0,0 +1,11 @@
+Google ChromeOS
+===============
+
+Currently there is no built in support for running sshuttle directly on
+Google ChromeOS/Chromebooks.
+
+What we can really do is to create a Linux VM with Crostini.  In the default
+stretch/Debian 9 VM, you can then install sshuttle as on any Linux box and
+it just works, as do xterms and ssvncviewer etc.
+
+https://www.reddit.com/r/Crostini/wiki/getstarted/crostini-setup-guide

docs/conf.py

@@ -0,0 +1,261 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+# sshuttle documentation build configuration file, created by
+# sphinx-quickstart on Sun Jan 17 12:13:47 2016.
+#
+# This file is execfile()d with the current directory set to its
+# containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys
+import os
+sys.path.insert(0, os.path.abspath('..'))
+import sshuttle  # NOQA
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+# sys.path.insert(0, os.path.abspath('.'))
+
+# -- General configuration ------------------------------------------------
+
+# If your documentation needs a minimal Sphinx version, state it here.
+# needs_sphinx = '1.0'
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    'sphinx.ext.todo',
+]
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix of source filenames.
+source_suffix = '.rst'
+
+# The encoding of source files.
+# source_encoding = 'utf-8-sig'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = 'sshuttle'
+copyright = '2016, Brian May'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The full version, including alpha/beta/rc tags.
+release = sshuttle.__version__
+# The short X.Y version.
+version = '.'.join(release.split('.')[:2])
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+# language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+# today = ''
+# Else, today_fmt is used as the format for a strftime call.
+# today_fmt = '%B %d, %Y'
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+exclude_patterns = ['_build']
+
+# The reST default role (used for this markup: `text`) to use for all
+# documents.
+# default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+# add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+# add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+# show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+# modindex_common_prefix = []
+
+# If true, keep warnings as "system message" paragraphs in the built documents.
+# keep_warnings = False
+
+
+# -- Options for HTML output ----------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+html_theme = 'furo'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+# html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+# html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+# html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+# html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+# html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+# html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# Add any extra paths that contain custom files (such as robots.txt or
+# .htaccess) here, relative to this directory. These files are copied
+# directly to the root of the documentation.
+# html_extra_path = []
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+# html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+# html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+# html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+# html_additional_pages = {}
+
+# If false, no module index is generated.
+# html_domain_indices = True
+
+# If false, no index is generated.
+# html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+# html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+# html_show_sourcelink = True
+
+# If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
+# html_show_sphinx = True
+
+# If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
+# html_show_copyright = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+# html_use_opensearch = ''
+
+# This is the file name suffix for HTML files (e.g. ".xhtml").
+# html_file_suffix = None
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'sshuttledoc'
+
+
+# -- Options for LaTeX output ---------------------------------------------
+
+latex_elements = {
+    # The paper size ('letterpaper' or 'a4paper').
+    # 'papersize': 'letterpaper',
+
+    # The font size ('10pt', '11pt' or '12pt').
+    # 'pointsize': '10pt',
+
+    # Additional stuff for the LaTeX preamble.
+    # 'preamble': '',
+}
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title,
+#  author, documentclass [howto, manual, or own class]).
+latex_documents = [
+    ('index', 'sshuttle.tex', 'sshuttle documentation', 'Brian May', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+# latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+# latex_use_parts = False
+
+# If true, show page references after internal links.
+# latex_show_pagerefs = False
+
+# If true, show URL addresses after external links.
+# latex_show_urls = False
+
+# Documents to append as an appendix to all manuals.
+# latex_appendices = []
+
+# If false, no module index is generated.
+# latex_domain_indices = True
+
+
+# -- Options for manual page output ---------------------------------------
+
+# One entry per manual page. List of tuples
+# (source start file, name, description, authors, manual section).
+man_pages = [
+    ('manpage', 'sshuttle', 'sshuttle documentation', ['Brian May'], 1)
+]
+
+# If true, show URL addresses after external links.
+# man_show_urls = False
+
+
+# -- Options for Texinfo output -------------------------------------------
+
+# Grouping the document tree into Texinfo files. List of tuples
+# (source start file, target name, title, author,
+#  dir menu entry, description, category)
+texinfo_documents = [
+    ('index', 'sshuttle', 'sshuttle documentation',
+     'Brian May', 'sshuttle', 'A transparent proxy-based VPN using ssh',
+     'Miscellaneous'),
+]
+
+# Documents to append as an appendix to all manuals.
+# texinfo_appendices = []
+
+# If false, no module index is generated.
+# texinfo_domain_indices = True
+
+# How to display URL addresses: 'footnote', 'no', or 'inline'.
+# texinfo_show_urls = 'footnote'
+
+# If true, do not generate a @detailmenu in the "Top" node's menu.
+# texinfo_no_detailmenu = False

docs/how-it-works.rst

@@ -0,0 +1,36 @@
+How it works
+============
+sshuttle is not exactly a VPN, and not exactly port forwarding.  It's kind
+of both, and kind of neither.
+
+It's like a VPN, since it can forward every port on an entire network, not
+just ports you specify.  Conveniently, it lets you use the "real" IP
+addresses of each host rather than faking port numbers on localhost.
+
+On the other hand, the way it *works* is more like ssh port forwarding than
+a VPN.  Normally, a VPN forwards your data one packet at a time, and
+doesn't care about individual connections; ie. it's "stateless" with respect
+to the traffic.  sshuttle is the opposite of stateless; it tracks every
+single connection.
+
+You could compare sshuttle to something like the old `Slirp
+<http://en.wikipedia.org/wiki/Slirp>`_ program, which was a userspace TCP/IP
+implementation that did something similar.  But it operated on a
+packet-by-packet basis on the client side, reassembling the packets on the
+server side.  That worked okay back in the "real live serial port" days,
+because serial ports had predictable latency and buffering.
+
+But you can't safely just forward TCP packets over a TCP session (like ssh),
+because TCP's performance depends fundamentally on packet loss; it
+*must* experience packet loss in order to know when to slow down!  At
+the same time, the outer TCP session (ssh, in this case) is a reliable
+transport, which means that what you forward through the tunnel *never*
+experiences packet loss.  The ssh session itself experiences packet loss, of
+course, but TCP fixes it up and ssh (and thus you) never know the
+difference.  But neither does your inner TCP session, and extremely screwy
+performance ensues.
+
+sshuttle assembles the TCP stream locally, multiplexes it statefully over
+an ssh session, and disassembles it back into packets at the other end.  So
+it never ends up doing TCP-over-TCP.  It's just data-over-TCP, which is
+safe.

docs/index.rst

@@ -0,0 +1,28 @@
+sshuttle: where transparent proxy meets VPN meets ssh
+=====================================================
+
+:Date: |today|
+:Version: |version|
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   overview
+   requirements
+   installation
+   usage
+   platform
+   Man Page <manpage>
+   how-it-works
+   support
+   trivia
+   changes
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`search`

docs/installation.rst

@@ -0,0 +1,84 @@
+Installation
+============
+
+- Ubuntu 16.04 or later::
+
+      apt-get install sshuttle
+
+- Debian stretch or later::
+
+      apt-get install sshuttle
+
+- Arch Linux::
+
+      pacman -S sshuttle
+
+- Fedora::
+
+      dnf install sshuttle
+
+- openSUSE::
+
+      zypper in sshuttle
+
+- Gentoo::
+
+      emerge -av net-proxy/sshuttle
+
+- NixOS::
+
+      nix-env -iA nixos.sshuttle
+
+- From PyPI::
+
+      sudo pip install sshuttle
+
+- Clone::
+
+      git clone https://github.com/sshuttle/sshuttle.git
+      cd sshuttle
+      sudo ./setup.py install
+
+- FreeBSD::
+
+      # ports
+      cd /usr/ports/net/py-sshuttle && make install clean
+      # pkg
+      pkg install py39-sshuttle
+
+- OpenBSD::
+
+      pkg_add sshuttle
+
+- macOS, via MacPorts::
+
+      sudo port selfupdate
+      sudo port install sshuttle
+
+It is also possible to install into a virtualenv as a non-root user.
+
+- From PyPI::
+
+      python3 -m venv /tmp/sshuttle
+      . /tmp/sshuttle/bin/activate
+      pip install sshuttle
+
+- Clone::
+
+      git clone https://github.com/sshuttle/sshuttle.git
+      cd sshuttle
+      python3 -m venv /tmp/sshuttle
+      . /tmp/sshuttle/bin/activate
+      python -m pip install .
+
+- Homebrew::
+
+      brew install sshuttle
+
+- Nix::
+
+      nix-shell -p sshuttle
+
+- Windows::
+
+      pip install sshuttle

docs/make.bat

@@ -0,0 +1,242 @@
+@ECHO OFF
+
+REM Command file for Sphinx documentation
+
+if "%SPHINXBUILD%" == "" (
+	set SPHINXBUILD=sphinx-build
+)
+set BUILDDIR=_build
+set ALLSPHINXOPTS=-d %BUILDDIR%/doctrees %SPHINXOPTS% .
+set I18NSPHINXOPTS=%SPHINXOPTS% .
+if NOT "%PAPER%" == "" (
+	set ALLSPHINXOPTS=-D latex_paper_size=%PAPER% %ALLSPHINXOPTS%
+	set I18NSPHINXOPTS=-D latex_paper_size=%PAPER% %I18NSPHINXOPTS%
+)
+
+if "%1" == "" goto help
+
+if "%1" == "help" (
+	:help
+	echo.Please use `make ^<target^>` where ^<target^> is one of
+	echo.  html       to make standalone HTML files
+	echo.  dirhtml    to make HTML files named index.html in directories
+	echo.  singlehtml to make a single large HTML file
+	echo.  pickle     to make pickle files
+	echo.  json       to make JSON files
+	echo.  htmlhelp   to make HTML files and a HTML help project
+	echo.  qthelp     to make HTML files and a qthelp project
+	echo.  devhelp    to make HTML files and a Devhelp project
+	echo.  epub       to make an epub
+	echo.  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter
+	echo.  text       to make text files
+	echo.  man        to make manual pages
+	echo.  texinfo    to make Texinfo files
+	echo.  gettext    to make PO message catalogs
+	echo.  changes    to make an overview over all changed/added/deprecated items
+	echo.  xml        to make Docutils-native XML files
+	echo.  pseudoxml  to make pseudoxml-XML files for display purposes
+	echo.  linkcheck  to check all external links for integrity
+	echo.  doctest    to run all doctests embedded in the documentation if enabled
+	goto end
+)
+
+if "%1" == "clean" (
+	for /d %%i in (%BUILDDIR%\*) do rmdir /q /s %%i
+	del /q /s %BUILDDIR%\*
+	goto end
+)
+
+
+%SPHINXBUILD% 2> nul
+if errorlevel 9009 (
+	echo.
+	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
+	echo.installed, then set the SPHINXBUILD environment variable to point
+	echo.to the full path of the 'sphinx-build' executable. Alternatively you
+	echo.may add the Sphinx directory to PATH.
+	echo.
+	echo.If you don't have Sphinx installed, grab it from
+	echo.http://sphinx-doc.org/
+	exit /b 1
+)
+
+if "%1" == "html" (
+	%SPHINXBUILD% -b html %ALLSPHINXOPTS% %BUILDDIR%/html
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The HTML pages are in %BUILDDIR%/html.
+	goto end
+)
+
+if "%1" == "dirhtml" (
+	%SPHINXBUILD% -b dirhtml %ALLSPHINXOPTS% %BUILDDIR%/dirhtml
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The HTML pages are in %BUILDDIR%/dirhtml.
+	goto end
+)
+
+if "%1" == "singlehtml" (
+	%SPHINXBUILD% -b singlehtml %ALLSPHINXOPTS% %BUILDDIR%/singlehtml
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The HTML pages are in %BUILDDIR%/singlehtml.
+	goto end
+)
+
+if "%1" == "pickle" (
+	%SPHINXBUILD% -b pickle %ALLSPHINXOPTS% %BUILDDIR%/pickle
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished; now you can process the pickle files.
+	goto end
+)
+
+if "%1" == "json" (
+	%SPHINXBUILD% -b json %ALLSPHINXOPTS% %BUILDDIR%/json
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished; now you can process the JSON files.
+	goto end
+)
+
+if "%1" == "htmlhelp" (
+	%SPHINXBUILD% -b htmlhelp %ALLSPHINXOPTS% %BUILDDIR%/htmlhelp
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished; now you can run HTML Help Workshop with the ^
+.hhp project file in %BUILDDIR%/htmlhelp.
+	goto end
+)
+
+if "%1" == "qthelp" (
+	%SPHINXBUILD% -b qthelp %ALLSPHINXOPTS% %BUILDDIR%/qthelp
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished; now you can run "qcollectiongenerator" with the ^
+.qhcp project file in %BUILDDIR%/qthelp, like this:
+	echo.^> qcollectiongenerator %BUILDDIR%\qthelp\sshuttle.qhcp
+	echo.To view the help file:
+	echo.^> assistant -collectionFile %BUILDDIR%\qthelp\sshuttle.ghc
+	goto end
+)
+
+if "%1" == "devhelp" (
+	%SPHINXBUILD% -b devhelp %ALLSPHINXOPTS% %BUILDDIR%/devhelp
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished.
+	goto end
+)
+
+if "%1" == "epub" (
+	%SPHINXBUILD% -b epub %ALLSPHINXOPTS% %BUILDDIR%/epub
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The epub file is in %BUILDDIR%/epub.
+	goto end
+)
+
+if "%1" == "latex" (
+	%SPHINXBUILD% -b latex %ALLSPHINXOPTS% %BUILDDIR%/latex
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished; the LaTeX files are in %BUILDDIR%/latex.
+	goto end
+)
+
+if "%1" == "latexpdf" (
+	%SPHINXBUILD% -b latex %ALLSPHINXOPTS% %BUILDDIR%/latex
+	cd %BUILDDIR%/latex
+	make all-pdf
+	cd %BUILDDIR%/..
+	echo.
+	echo.Build finished; the PDF files are in %BUILDDIR%/latex.
+	goto end
+)
+
+if "%1" == "latexpdfja" (
+	%SPHINXBUILD% -b latex %ALLSPHINXOPTS% %BUILDDIR%/latex
+	cd %BUILDDIR%/latex
+	make all-pdf-ja
+	cd %BUILDDIR%/..
+	echo.
+	echo.Build finished; the PDF files are in %BUILDDIR%/latex.
+	goto end
+)
+
+if "%1" == "text" (
+	%SPHINXBUILD% -b text %ALLSPHINXOPTS% %BUILDDIR%/text
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The text files are in %BUILDDIR%/text.
+	goto end
+)
+
+if "%1" == "man" (
+	%SPHINXBUILD% -b man %ALLSPHINXOPTS% %BUILDDIR%/man
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The manual pages are in %BUILDDIR%/man.
+	goto end
+)
+
+if "%1" == "texinfo" (
+	%SPHINXBUILD% -b texinfo %ALLSPHINXOPTS% %BUILDDIR%/texinfo
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The Texinfo files are in %BUILDDIR%/texinfo.
+	goto end
+)
+
+if "%1" == "gettext" (
+	%SPHINXBUILD% -b gettext %I18NSPHINXOPTS% %BUILDDIR%/locale
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The message catalogs are in %BUILDDIR%/locale.
+	goto end
+)
+
+if "%1" == "changes" (
+	%SPHINXBUILD% -b changes %ALLSPHINXOPTS% %BUILDDIR%/changes
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.The overview file is in %BUILDDIR%/changes.
+	goto end
+)
+
+if "%1" == "linkcheck" (
+	%SPHINXBUILD% -b linkcheck %ALLSPHINXOPTS% %BUILDDIR%/linkcheck
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Link check complete; look for any errors in the above output ^
+or in %BUILDDIR%/linkcheck/output.txt.
+	goto end
+)
+
+if "%1" == "doctest" (
+	%SPHINXBUILD% -b doctest %ALLSPHINXOPTS% %BUILDDIR%/doctest
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Testing of doctests in the sources finished, look at the ^
+results in %BUILDDIR%/doctest/output.txt.
+	goto end
+)
+
+if "%1" == "xml" (
+	%SPHINXBUILD% -b xml %ALLSPHINXOPTS% %BUILDDIR%/xml
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The XML files are in %BUILDDIR%/xml.
+	goto end
+)
+
+if "%1" == "pseudoxml" (
+	%SPHINXBUILD% -b pseudoxml %ALLSPHINXOPTS% %BUILDDIR%/pseudoxml
+	if errorlevel 1 exit /b 1
+	echo.
+	echo.Build finished. The pseudo-XML files are in %BUILDDIR%/pseudoxml.
+	goto end
+)
+
+:end

docs/manpage.rst

@@ -0,0 +1,503 @@
+sshuttle
+========
+
+
+Synopsis
+--------
+**sshuttle** [*options*] **-r** *[username@]sshserver[:port]* \<*subnets* ...\>
+
+
+Description
+-----------
+:program:`sshuttle` allows you to create a VPN connection from your
+machine to any remote server that you can connect to via ssh, as long
+as that server has a sufficiently new Python installation.
+
+To work, you must have root access on the local machine,
+but you can have a normal account on the server.
+
+It's valid to run :program:`sshuttle` more than once simultaneously on
+a single client machine, connecting to a different server
+every time, so you can be on more than one VPN at once.
+
+If run on a router, :program:`sshuttle` can forward traffic for your
+entire subnet to the VPN.
+
+
+Options
+-------
+.. program:: sshuttle
+
+.. option:: <subnets>
+
+    A list of subnets to route over the VPN, in the form
+    ``a.b.c.d[/width][port[-port]]``. Valid examples are 1.2.3.4 (a
+    single IP address) and 1.2.3.4/32 (equivalent to 1.2.3.4),
+    1.2.3.0/24 (a 24-bit subnet, ie. with a 255.255.255.0 netmask).
+    Specify subnets 0/0 to match all IPv4 addresses and ::/0 to match
+    all IPv6 addresses. Any of the previous examples are also valid if
+    you append a port or a port range, so 1.2.3.4:8000 will only
+    tunnel traffic that has as the destination port 8000 of 1.2.3.4
+    and 1.2.3.0/24:8000-9000 will tunnel traffic going to any port
+    between 8000 and 9000 (inclusive) for all IPs in the 1.2.3.0/24
+    subnet. A hostname can be provided instead of an IP address. If
+    the hostname resolves to multiple IPs, all of the IPs are
+    included. If a width is provided with a hostname, the width is
+    applied to all of the hostnames IPs (if they are all either IPv4
+    or IPv6). Widths cannot be supplied to hostnames that resolve to
+    both IPv4 and IPv6. Valid examples are example.com,
+    example.com:8000, example.com/24, example.com/24:8000 and
+    example.com:8000-9000.
+
+.. option:: --method <auto|nat|nft|tproxy|pf|ipfw>
+
+   Which firewall method should sshuttle use? For auto, sshuttle attempts to
+   guess the appropriate method depending on what it can find in PATH. The
+   default value is auto.
+
+.. option:: -l <[ip:]port>, --listen=<[ip:]port>
+
+    Use this ip address and port number as the transparent
+    proxy port.  By default :program:`sshuttle` finds an available
+    port automatically and listens on IP 127.0.0.1
+    (localhost), so you don't need to override it, and
+    connections are only proxied from the local machine,
+    not from outside machines.  If you want to accept
+    connections from other machines on your network (ie. to
+    run :program:`sshuttle` on a router) try enabling IP Forwarding in
+    your kernel, then using ``--listen 0.0.0.0:0``.
+    You can use any name resolving to an IP address of the machine running
+    :program:`sshuttle`, e.g. ``--listen localhost``.
+
+    For the nft, tproxy and pf methods this can be an IPv6 address. Use
+    this option with comma separated values if required, to provide both
+    IPv4 and IPv6 addresses, e.g. ``--listen 127.0.0.1:0,[::1]:0``.
+
+.. option:: -H, --auto-hosts
+
+    Scan for remote hostnames and update the local /etc/hosts
+    file with matching entries for as long as the VPN is
+    open.  This is nicer than changing your system's DNS
+    (/etc/resolv.conf) settings, for several reasons.  First,
+    hostnames are added without domain names attached, so
+    you can ``ssh thatserver`` without worrying if your local
+    domain matches the remote one.  Second, if you :program:`sshuttle`
+    into more than one VPN at a time, it's impossible to
+    use more than one DNS server at once anyway, but
+    :program:`sshuttle` correctly merges /etc/hosts entries between
+    all running copies.  Third, if you're only routing a
+    few subnets over the VPN, you probably would prefer to
+    keep using your local DNS server for everything else.
+
+    :program:`sshuttle` tries to store a cache of the hostnames in
+    ~/.sshuttle.hosts on the remote host. Similarly, it tries to read
+    the file when you later reconnect to the host with --auto-hosts
+    enabled to quickly populate the host list. When troubleshooting
+    this feature, try removing this file on the remote host when
+    sshuttle is not running.
+
+.. option:: -N, --auto-nets
+
+    In addition to the subnets provided on the command
+    line, ask the server which subnets it thinks we should
+    route, and route those automatically.  The suggestions
+    are taken automatically from the server's routing
+    table.
+
+    This feature does not detect IPv6 routes. Specify IPv6 subnets
+    manually. For example, specify the ``::/0`` subnet on the command
+    line to route all IPv6 traffic.
+
+.. option:: --dns
+
+    Capture local DNS requests and forward to the remote DNS
+    server. All queries to any of the local system's DNS
+    servers (/etc/resolv.conf and, if it exists,
+    /run/systemd/resolve/resolv.conf) will be intercepted and
+    resolved on the remote side of the tunnel instead, there
+    using the DNS specified via the :option:`--to-ns` option,
+    if specified. Only plain DNS traffic sent to these servers
+    on port 53 are captured.
+
+.. option:: --ns-hosts=<server1[,server2[,server3[...]]]>
+
+    Capture local DNS requests to the specified server(s)
+    and forward to the remote DNS server. Contrary to the
+    :option:`--dns` option, this flag allows to specify the
+    DNS server(s) the queries to which to intercept,
+    instead of intercepting all DNS traffic on the local
+    machine. This can be useful when only certain DNS
+    requests should be resolved on the remote side of the
+    tunnel, e.g. in combination with dnsmasq.
+
+.. option:: --to-ns=<server>
+
+    The DNS to forward requests to when remote DNS
+    resolution is enabled. If not given, sshuttle will
+    simply resolve using the system configured resolver on
+    the remote side (via /etc/resolv.conf on the remote
+    side).
+
+.. option:: --python
+
+    Specify the name/path of the remote python interpreter. The
+    default is to use ``python3`` (or ``python``, if ``python3``
+    fails) in the remote system's PATH.
+
+.. option:: -r <[username@]sshserver[:port]>, --remote=<[username@]sshserver[:port]>
+
+    The remote hostname and optional username and ssh
+    port number to use for connecting to the remote server.
+    For example, example.com, testuser@example.com,
+    testuser@example.com:2222, or example.com:2244. This
+    hostname is passed to ssh, so it will recognize any
+    aliases and settings you may have configured in
+    ~/.ssh/config.
+
+.. option:: -x <subnet>, --exclude=<subnet>
+
+    Explicitly exclude this subnet from forwarding.  The
+    format of this option is the same as the ``<subnets>``
+    option.  To exclude more than one subnet, specify the
+    ``-x`` option more than once.  You can say something like
+    ``0/0 -x 1.2.3.0/24`` to forward everything except the
+    local subnet over the VPN, for example.
+
+.. option:: -X <file>, --exclude-from=<file>
+
+    Exclude the subnets specified in a file, one subnet per
+    line. Useful when you have lots of subnets to exclude.
+
+.. option:: -v, --verbose
+
+    Print more information about the session.  This option
+    can be used more than once for increased verbosity.  By
+    default, :program:`sshuttle` prints only error messages.
+
+.. option:: -e, --ssh-cmd
+
+    The command to use to connect to the remote server. The
+    default is just ``ssh``.  Use this if your ssh client is
+    in a non-standard location or you want to provide extra
+    options to the ssh command, for example, ``-e 'ssh -v'``.
+
+.. option:: --remote-shell
+
+    For Windows targets, specify configured remote shell program alternative to defacto posix shell.
+    It would be either ``cmd`` or ``powershell`` unless something like git-bash is in use.
+
+.. option:: --no-cmd-delimiter
+
+    Do not add a double dash (--) delimiter before invoking Python on
+    the remote host. This option is useful when the ssh command used
+    to connect is a custom command that does not interpret this
+    delimiter correctly.
+
+.. option:: --seed-hosts
+
+    A comma-separated list of hostnames to use to
+    initialize the :option:`--auto-hosts` scan algorithm.
+    :option:`--auto-hosts` does things like poll netstat output
+    for lists of local hostnames, but can speed things up
+    if you use this option to give it a few names to start
+    from.
+
+    If this option is used *without* :option:`--auto-hosts`,
+    then the listed hostnames will be scanned and added, but
+    no further hostnames will be added.
+
+.. option:: --no-latency-control
+
+    Sacrifice latency to improve bandwidth benchmarks. ssh
+    uses really big socket buffers, which can overload the
+    connection if you start doing large file transfers,
+    thus making all your other sessions inside the same
+    tunnel go slowly. Normally, :program:`sshuttle` tries to avoid
+    this problem using a "fullness check" that allows only
+    a certain amount of outstanding data to be buffered at
+    a time.  But on high-bandwidth links, this can leave a
+    lot of your bandwidth underutilized.  It also makes
+    :program:`sshuttle` seem slow in bandwidth benchmarks (benchmarks
+    rarely test ping latency, which is what :program:`sshuttle` is
+    trying to control).  This option disables the latency
+    control feature, maximizing bandwidth usage.  Use at
+    your own risk.
+
+.. option:: --latency-buffer-size
+
+    Set the size of the buffer used in latency control. The
+    default is ``32768``. Changing this option allows a compromise
+    to be made between latency and bandwidth without completely
+    disabling latency control (with :option:`--no-latency-control`).
+
+.. option:: -D, --daemon
+
+    Automatically fork into the background after connecting
+    to the remote server.  Implies :option:`--syslog`.
+
+.. option:: -s <file>, --subnets=<file>
+
+    Include the subnets specified in a file instead of on the
+    command line. One subnet per line.
+
+.. option:: --syslog
+
+    after connecting, send all log messages to the
+    :manpage:`syslog(3)` service instead of stderr.  This is
+    implicit if you use :option:`--daemon`.
+
+.. option:: --pidfile=<pidfilename>
+
+    when using :option:`--daemon`, save :program:`sshuttle`'s pid to
+    *pidfilename*.  The default is ``sshuttle.pid`` in the
+    current directory.
+
+.. option:: --disable-ipv6
+
+    Disable IPv6 support for methods that support it (nat, nft,
+    tproxy, and pf).
+
+.. option:: --firewall
+
+    (internal use only) run the firewall manager.  This is
+    the only part of :program:`sshuttle` that must run as root.  If
+    you start :program:`sshuttle` as a non-root user, it will
+    automatically run ``sudo`` or ``su`` to start the firewall
+    manager, but the core of :program:`sshuttle` still runs as a
+    normal user.
+
+.. option:: --hostwatch
+
+    (internal use only) run the hostwatch daemon.  This
+    process runs on the server side and collects hostnames for
+    the :option:`--auto-hosts` option.  Using this option by itself
+    makes it a lot easier to debug and test the :option:`--auto-hosts`
+    feature.
+
+.. option:: --sudoers-no-modify
+
+    sshuttle prints a configuration to stdout which allows a user to
+    run sshuttle without a password. This option is INSECURE because,
+    with some cleverness, it also allows the user to run any command
+    as root without a password. The output also includes a suggested
+    method for you to install the configuration.
+
+    Use --sudoers-user to modify the user that it applies to.
+
+.. option:: --sudoers-user
+
+    Set the user name or group with %group_name for passwordless
+    operation. Default is the current user. Set to ALL for all users
+    (NOT RECOMMENDED: See note about security in --sudoers-no-modify
+    documentation above). Only works with the --sudoers-no-modify
+    option.
+
+.. option:: -t <mark>, --tmark=<mark>
+
+    An option used by the tproxy method: Use the specified traffic
+    mark. The mark must be a hexadecimal value. Defaults to 0x01.
+
+.. option:: --version
+
+    Print program version.
+
+
+Configuration File
+------------------
+All the options described above can optionally be specified in a configuration
+file.
+
+To run :program:`sshuttle` with options defined in, e.g., `/etc/sshuttle.conf`
+just pass the path to the file preceded by the `@` character, e.g.
+`@/etc/sshuttle.conf`.
+
+When running :program:`sshuttle` with options defined in a configuration file,
+options can still be passed via the command line in addition to what is
+defined in the file. If a given option is defined both in the file and in
+the command line, the value in the command line will take precedence.
+
+Arguments read from a file must be one per line, as shown below::
+
+    value
+    --option1
+    value1
+    --option2
+    value2
+
+The configuration file supports comments for human-readable
+annotations. For example::
+
+    # company-internal API
+    8.8.8.8/32
+    # home IoT
+    192.168.63.0/24
+
+
+Environment Variable
+--------------------
+
+You can specify command line options with the `SSHUTTLE_ARGS` environment
+variable. If a given option is defined in both the environment variable and
+command line, the value on the command line will take precedence.
+
+For example::
+
+    SSHUTTLE_ARGS="-e 'ssh -v' --dns" sshuttle -r example.com 0/0
+
+
+Examples
+--------
+
+Use the following command to route all IPv4 TCP traffic through remote
+(-r) host example.com (and possibly other traffic too, depending on
+the selected --method). The 0/0 subnet, short for 0.0.0.0/0, matches
+all IPv4 addresses. The ::/0 subnet, matching all IPv6 addresses could
+be added to the example. We also exclude (-x) example.com:22 so that
+we can establish ssh connections from our local machine to the remote
+host without them being routed through sshuttle. Excluding the remote
+host may be necessary on some machines for sshuttle to work properly.
+Press Ctrl+C to exit. To also route DNS queries through sshuttle, try
+adding --dns. Add or remove -v options to see more or less
+information::
+
+    $ sshuttle -r example.com -x example.com:22 0/0
+
+    Starting sshuttle proxy (version ...).
+    [local sudo] Password:
+    fw: Starting firewall with Python version 3.9.5
+    fw: ready method name nat.
+    c : IPv6 disabled since it isn't supported by method nat.
+    c : Method: nat
+    c : IPv4: on
+    c : IPv6: off (not available with nat method)
+    c : UDP : off (not available with nat method)
+    c : DNS : off (available)
+    c : User: off (available)
+    c : Subnets to forward through remote host (type, IP, cidr mask width, startPort, endPort):
+    c :   (<AddressFamily.AF_INET: 2>, '0.0.0.0', 0, 0, 0)
+    c : Subnets to exclude from forwarding:
+    c :   (<AddressFamily.AF_INET: 2>, '...', 32, 22, 22)
+    c :   (<AddressFamily.AF_INET: 2>, '127.0.0.1', 32, 0, 0)
+    c : TCP redirector listening on ('127.0.0.1', 12299).
+    c : Starting client with Python version 3.9.5
+    c : Connecting to server...
+    user@example.com's password:
+     s: Starting server with Python version 3.6.8
+     s: latency control setting = True
+     s: auto-nets:False
+    c : Connected to server.
+    fw: setting up.
+    fw: iptables -w -t nat -N sshuttle-12299
+    fw: iptables -w -t nat -F sshuttle-12299
+    ...
+    Accept: 192.168.42.121:60554 -> 77.141.99.22:22.
+    ^C
+    c : Keyboard interrupt: exiting.
+    c : SW'unknown':Mux#1: deleting (1 remain)
+    c : SW#7:192.168.42.121:60554: deleting (0 remain)
+
+
+Connect to a remote server, with automatic hostname
+and subnet guessing::
+
+    $ sshuttle -vNHr example.com -x example.com:22
+    Starting sshuttle proxy (version ...).
+    [local sudo] Password:
+    fw: Starting firewall with Python version 3.9.5
+    fw: ready method name nat.
+    c : IPv6 disabled since it isn't supported by method nat.
+    c : Method: nat
+    c : IPv4: on
+    c : IPv6: off (not available with nat method)
+    c : UDP : off (not available with nat method)
+    c : DNS : off (available)
+    c : User: off (available)
+    c : Subnets to forward through remote host (type, IP, cidr mask width, startPort, endPort):
+    c : NOTE: Additional subnets to forward may be added below by --auto-nets.
+    c : Subnets to exclude from forwarding:
+    c :   (<AddressFamily.AF_INET: 2>, '...', 32, 22, 22)
+    c :   (<AddressFamily.AF_INET: 2>, '127.0.0.1', 32, 0, 0)
+    c : TCP redirector listening on ('127.0.0.1', 12300).
+    c : Starting client with Python version 3.9.5
+    c : Connecting to server...
+    user@example.com's password:
+     s: Starting server with Python version 3.6.8
+     s: latency control setting = True
+     s: auto-nets:True
+    c : Connected to server.
+    c : seed_hosts: []
+     s: available routes:
+     s:   77.141.99.0/24
+    fw: setting up.
+    fw: iptables -w -t nat -N sshuttle-12300
+    fw: iptables -w -t nat -F sshuttle-12300
+    ...
+    c : Accept: 192.168.42.121:60554 -> 77.141.99.22:22.
+    ^C
+    c : Keyboard interrupt: exiting.
+    c : SW'unknown':Mux#1: deleting (1 remain)
+    c : SW#7:192.168.42.121:60554: deleting (0 remain)
+
+Run :program:`sshuttle` with a `/etc/sshuttle.conf` configuration file::
+
+    $ sshuttle @/etc/sshuttle.conf
+
+Use the options defined in `/etc/sshuttle.conf` but be more verbose::
+
+    $ sshuttle @/etc/sshuttle.conf -vvv
+
+Override the remote server defined in `/etc/sshuttle.conf`::
+
+    $ sshuttle @/etc/sshuttle.conf -r otheruser@test.example.com
+
+Example configuration file::
+
+    192.168.0.0/16
+    --remote
+    user@example.com
+
+
+Discussion
+----------
+When it starts, :program:`sshuttle` creates an ssh session to the
+server specified by the ``-r`` option.
+
+After connecting to the remote server, :program:`sshuttle` uploads its
+(python) source code to the remote end and executes it
+there.  Thus, you don't need to install :program:`sshuttle` on the
+remote server, and there are never :program:`sshuttle` version
+conflicts between client and server.
+
+Unlike most VPNs, :program:`sshuttle` forwards sessions, not packets.
+That is, it uses kernel transparent proxying (`iptables
+REDIRECT` rules on Linux) to
+capture outgoing TCP sessions, then creates entirely
+separate TCP sessions out to the original destination at
+the other end of the tunnel.
+
+Packet-level forwarding (eg. using the tun/tap devices on
+Linux) seems elegant at first, but it results in
+several problems, notably the 'tcp over tcp' problem.  The
+tcp protocol depends fundamentally on packets being dropped
+in order to implement its congestion control algorithm; if
+you pass tcp packets through a tcp-based tunnel (such as
+ssh), the inner tcp packets will never be dropped, and so
+the inner tcp stream's congestion control will be
+completely broken, and performance will be terrible.  Thus,
+packet-based VPNs (such as IPsec and openvpn) cannot use
+tcp-based encrypted streams like ssh or ssl, and have to
+implement their own encryption from scratch, which is very
+complex and error prone.
+
+:program:`sshuttle`'s simplicity comes from the fact that it can
+safely use the existing ssh encrypted tunnel without
+incurring a performance penalty.  It does this by letting
+the client-side kernel manage the incoming tcp stream, and
+the server-side kernel manage the outgoing tcp stream;
+there is no need for congestion control to be shared
+between the two separate streams, so a tcp-based tunnel is
+fine.
+
+.. seealso::
+
+   :manpage:`ssh(1)`, :manpage:`python(1)`

docs/openwrt.rst

@@ -0,0 +1,8 @@
+OpenWRT
+========
+
+Run::
+
+    opkg install python3 python3-pip iptables-mod-extra iptables-mod-nat-extra iptables-mod-ipopt
+    python3 /usr/bin/pip3 install sshuttle
+    sshuttle -l 0.0.0.0 -r <IP> -x 192.168.1.1 0/0

docs/overview.rst

@@ -0,0 +1,26 @@
+Overview
+========
+
+As far as I know, sshuttle is the only program that solves the following
+common case:
+
+- Your client machine (or router) is Linux, MacOS, FreeBSD, OpenBSD or pfSense.
+
+- You have access to a remote network via ssh.
+
+- You don't necessarily have admin access on the remote network.
+
+- The remote network has no VPN, or only stupid/complex VPN
+  protocols (IPsec, PPTP, etc). Or maybe you *are* the
+  admin and you just got frustrated with the awful state of
+  VPN tools.
+
+- You don't want to create an ssh port forward for every
+  single host/port on the remote network.
+
+- You hate openssh's port forwarding because it's randomly
+  slow and/or stupid.
+
+- You can't use openssh's PermitTunnel feature because
+  it's disabled by default on openssh servers; plus it does
+  TCP-over-TCP, which has terrible performance (see below).

docs/platform.rst

@@ -0,0 +1,12 @@
+Platform Specific Notes
+=======================
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   chromeos
+   tproxy
+   windows
+   openwrt

docs/requirements.rst

@@ -0,0 +1,97 @@
+Requirements
+============
+
+Client side Requirements
+------------------------
+
+- sudo, or root access on your client machine.
+  (The server doesn't need admin access.)
+- Python 3.9 or greater.
+
+
+Linux with NAT method
+~~~~~~~~~~~~~~~~~~~~~
+Supports:
+
+* IPv4 TCP
+* IPv4 DNS
+* IPv6 TCP
+* IPv6 DNS
+
+Requires:
+
+* iptables DNAT and REDIRECT modules. ip6tables for IPv6.
+
+Linux with nft method
+~~~~~~~~~~~~~~~~~~~~~
+Supports
+
+* IPv4 TCP
+* IPv4 DNS
+* IPv6 TCP
+* IPv6 DNS
+
+Requires:
+
+* nftables
+
+Linux with TPROXY method
+~~~~~~~~~~~~~~~~~~~~~~~~
+Supports:
+
+* IPv4 TCP
+* IPv4 UDP
+* IPv4 DNS
+* IPv6 TCP
+* IPv6 UDP
+* IPv6 DNS
+
+
+MacOS / FreeBSD / OpenBSD / pfSense
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Method: pf
+
+Supports:
+
+* IPv4 TCP
+* IPv4 DNS
+* IPv6 TCP
+* IPv6 DNS
+
+Requires:
+
+* You need to have the pfctl command.
+
+Windows
+~~~~~~~
+
+Experimental built-in support available. See :doc:`windows` for more information.
+
+
+Server side Requirements
+------------------------
+
+- Python 3.9 or greater.
+
+
+Additional Suggested Software
+-----------------------------
+
+- If you are using systemd, sshuttle can notify it when the connection to
+  the remote end is established and the firewall rules are installed. For
+  this feature to work you must configure the process start-up type for the
+  sshuttle service unit to notify, as shown in the example below.
+
+.. code-block:: ini
+   :emphasize-lines: 6
+
+   [Unit]
+   Description=sshuttle
+   After=network.target
+
+   [Service]
+   Type=notify
+   ExecStart=/usr/bin/sshuttle --dns --remote <user>@<server> <subnets...>
+
+   [Install]
+   WantedBy=multi-user.target

docs/support.rst

@@ -0,0 +1,11 @@
+Support
+=======
+
+Mailing list:
+
+* Subscribe by sending a message to <sshuttle+subscribe@googlegroups.com>
+* List archives are at: http://groups.google.com/group/sshuttle
+
+Issue tracker and pull requests at github:
+
+* https://github.com/sshuttle/sshuttle

docs/tproxy.rst

@@ -0,0 +1,40 @@
+TPROXY
+======
+TPROXY is the only method that supports UDP.
+
+There are some things you need to consider for TPROXY to work:
+
+- The following commands need to be run first as root. This only needs to be
+  done once after booting up::
+
+      ip route add local default dev lo table 100
+      ip rule add fwmark {TMARK} lookup 100
+      ip -6 route add local default dev lo table 100
+      ip -6 rule add fwmark {TMARK} lookup 100
+
+  where {TMARK} is the identifier mark passed with -t or --tmark flag
+  as a hexadecimal string (default value is '0x01').
+
+- The ``--auto-nets`` feature does not detect IPv6 routes automatically. Add IPv6
+  routes manually. e.g. by adding ``'::/0'`` to the end of the command line.
+
+- The client needs to be run as root. e.g.::
+
+      sudo SSH_AUTH_SOCK="$SSH_AUTH_SOCK" $HOME/tree/sshuttle.tproxy/sshuttle --method=tproxy ...
+
+- You may need to exclude the IP address of the server you are connecting to.
+  Otherwise sshuttle may attempt to intercept the ssh packets, which will not
+  work. Use the ``--exclude`` parameter for this.
+
+- You need the ``--method=tproxy`` parameter, as above.
+
+- The routes for the outgoing packets must already exist. For example, if your
+  connection does not have IPv6 support, no IPv6 routes will exist, IPv6
+  packets will not be generated and sshuttle cannot intercept them::
+
+      telnet -6 www.google.com 80
+      Trying 2404:6800:4001:805::1010...
+      telnet: Unable to connect to remote host: Network is unreachable
+
+  Add some dummy routes to external interfaces. Make sure they get removed
+  however after sshuttle exits.

docs/trivia.rst

@@ -0,0 +1,35 @@
+Useless Trivia
+==============
+This section written by the original author, Avery Pennarun
+<apenwarr@gmail.com>.
+
+Back in 1998, I released the first version of `Tunnel
+Vision <http://alumnit.ca/wiki/?TunnelVisionReadMe>`_, a semi-intelligent VPN
+client for Linux.  Unfortunately, I made two big mistakes: I implemented the
+key exchange myself (oops), and I ended up doing TCP-over-TCP (double oops).
+The resulting program worked okay - and people used it for years - but the
+performance was always a bit funny.  And nobody ever found any security flaws
+in my key exchange, either, but that doesn't mean anything. :)
+
+The same year, dcoombs and I also released Fast Forward, a proxy server
+supporting transparent proxying.  Among other things, we used it for
+automatically splitting traffic across more than one Internet connection (a
+tool we called "Double Vision").
+
+I was still in university at the time.  A couple years after that, one of my
+professors was working with some graduate students on the technology that would
+eventually become `Slipstream Internet Acceleration
+<http://www.slipstream.com/>`_.  He asked me to do a contract for him to build
+an initial prototype of a transparent proxy server for mobile networks.  The
+idea was similar to sshuttle: if you reassemble and then disassemble the TCP
+packets, you can reduce latency and improve performance vs.  just forwarding
+the packets over a plain VPN or mobile network.  (It's unlikely that any of my
+code has persisted in the Slipstream product today, but the concept is still
+pretty cool.  I'm still horrified that people use plain TCP on complex mobile
+networks with crazily variable latency, for which it was never really
+intended.)
+
+That project I did for Slipstream was what first gave me the idea to merge
+the concepts of Fast Forward, Double Vision, and Tunnel Vision into a single
+program that was the best of all worlds.  And here we are, at last.
+You're welcome.

docs/usage.rst

@@ -0,0 +1,93 @@
+Usage
+=====
+
+.. note::
+
+    For information on usage with Windows, see the :doc:`windows` section.
+    For information on using the TProxy method, see the :doc:`tproxy` section.
+
+Forward all traffic::
+
+    sshuttle -r username@sshserver 0.0.0.0/0
+
+- Use the :option:`sshuttle -r` parameter to specify a remote server.
+  On some systems, you may also need to use the :option:`sshuttle -x`
+  parameter to exclude sshserver or sshserver:22 so that your local
+  machine can communicate directly to sshserver without it being
+  redirected by sshuttle.
+
+- By default sshuttle will automatically choose a method to use. Override with
+  the :option:`sshuttle --method` parameter.
+
+- There is a shortcut for 0.0.0.0/0 for those that value
+  their wrists::
+
+      sshuttle -r username@sshserver 0/0
+
+
+- For 'My VPN broke and need a temporary solution FAST to access local IPv4 addresses'::
+
+      sshuttle --dns -NHr username@sshserver 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
+
+If you would also like your DNS queries to be proxied
+through the DNS server of the server you are connect to::
+
+  sshuttle --dns -r username@sshserver 0/0
+
+The above is probably what you want to use to prevent
+local network attacks such as Firesheep and friends.
+See the documentation for the :option:`sshuttle --dns` parameter.
+
+(You may be prompted for one or more passwords; first, the local password to
+become root using sudo, and then the remote ssh password.  Or you might have
+sudo and ssh set up to not require passwords, in which case you won't be
+prompted at all.)
+
+
+Usage Notes
+-----------
+That's it!  Now your local machine can access the remote network as if you
+were right there.  And if your "client" machine is a router, everyone on
+your local network can make connections to your remote network.
+
+You don't need to install sshuttle on the remote server;
+the remote server just needs to have python available.
+sshuttle will automatically upload and run its source code
+to the remote python interpreter.
+
+This creates a transparent proxy server on your local machine for all IP
+addresses that match 0.0.0.0/0.  (You can use more specific IP addresses if
+you want; use any number of IP addresses or subnets to change which
+addresses get proxied.  Using 0.0.0.0/0 proxies *everything*, which is
+interesting if you don't trust the people on your local network.)
+
+Any TCP session you initiate to one of the proxied IP addresses will be
+captured by sshuttle and sent over an ssh session to the remote copy of
+sshuttle, which will then regenerate the connection on that end, and funnel
+the data back and forth through ssh.
+
+Fun, right?  A poor man's instant VPN, and you don't even have to have
+admin access on the server.
+
+Sudoers File
+------------
+
+sshuttle can generate a sudoers.d file for Linux and MacOS. This
+allows one or more users to run sshuttle without entering the
+local sudo password. **WARNING:** This option is *insecure*
+because, with some cleverness, it also allows these users to run any
+command (via the --ssh-cmd option) as root without a password.
+
+To print a sudo configuration file and see a suggested way to install it, run::
+
+  sshuttle --sudoers-no-modify
+
+A custom user or group can be set with the 
+:option:`sshuttle --sudoers-no-modify --sudoers-user {user_descriptor}`
+option. Valid values for this vary based on how your system is configured.
+Values such as usernames, groups prepended with `%` and sudoers user 
+aliases will work. See the sudoers manual for more information on valid
+user-specified actions. The option must be used with `--sudoers-no-modify`::
+
+  sshuttle --sudoers-no-modify --sudoers-user mike
+  sshuttle --sudoers-no-modify --sudoers-user %sudo

docs/windows.rst

@@ -0,0 +1,28 @@
+Microsoft Windows
+=================
+
+Experimental native support::
+
+Experimental built-in support for Windows is available through `windivert` method.
+You have to install https://pypi.org/project/pydivert package.  You need Administrator privileges to use windivert method
+
+Notes
+-  sshuttle should be executed from admin shell (Automatic firewall process admin elevation is not available)
+-  TCP/IPv4 supported (IPv6/UDP/DNS are not available)
+
+Use Linux VM on Windows::
+
+What we can really do is to create a Linux VM with Vagrant (or simply
+Virtualbox if you like). In the Vagrant settings, remember to turn on bridged
+NIC. Then, run sshuttle inside the VM like below::
+
+    sshuttle -l 0.0.0.0 -x 10.0.0.0/8 -x 192.168.0.0/16 0/0
+
+10.0.0.0/8 excludes NAT traffic of Vagrant and 192.168.0.0/16 excludes
+traffic to local area network (assuming that we're using 192.168.0.0 subnet).
+
+Assuming the VM has the IP 192.168.1.200 obtained on the bridge NIC (we can
+configure that in Vagrant), we can then ask Windows to route all its traffic
+via the VM by running the following in cmd.exe with admin right::
+
+    route add 0.0.0.0 mask 0.0.0.0 192.168.1.200

firewall.py

@@ -1,300 +0,0 @@
-import re, errno
-import compat.ssubprocess as ssubprocess
-import helpers
-from helpers import *
-
-
-def ipt_chain_exists(name):
-    argv = ['iptables', '-t', 'nat', '-nL']
-    p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
-    for line in p.stdout:
-        if line.startswith('Chain %s ' % name):
-            return True
-    rv = p.wait()
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-
-
-def ipt(*args):
-    argv = ['iptables', '-t', 'nat'] + list(args)
-    debug1('>> %s\n' % ' '.join(argv))
-    rv = ssubprocess.call(argv)
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-
-
-# We name the chain based on the transproxy port number so that it's possible
-# to run multiple copies of sshuttle at the same time.  Of course, the
-# multiple copies shouldn't have overlapping subnets, or only the most-
-# recently-started one will win (because we use "-I OUTPUT 1" instead of
-# "-A OUTPUT").
-def do_iptables(port, subnets):
-    chain = 'sshuttle-%s' % port
-
-    # basic cleanup/setup of chains
-    if ipt_chain_exists(chain):
-        ipt('-D', 'OUTPUT', '-j', chain)
-        ipt('-D', 'PREROUTING', '-j', chain)
-        ipt('-F', chain)
-        ipt('-X', chain)
-
-    if subnets:
-        ipt('-N', chain)
-        ipt('-F', chain)
-        ipt('-I', 'OUTPUT', '1', '-j', chain)
-        ipt('-I', 'PREROUTING', '1', '-j', chain)
-
-        # create new subnet entries.  Note that we're sorting in a very
-        # particular order: we need to go from most-specific (largest swidth)
-        # to least-specific, and at any given level of specificity, we want
-        # excludes to come first.  That's why the columns are in such a non-
-        # intuitive order.
-        for swidth,sexclude,snet in sorted(subnets, reverse=True):
-            if sexclude:
-                ipt('-A', chain, '-j', 'RETURN',
-                    '--dest', '%s/%s' % (snet,swidth),
-                    '-p', 'tcp')
-            else:
-                ipt('-A', chain, '-j', 'REDIRECT',
-                    '--dest', '%s/%s' % (snet,swidth),
-                    '-p', 'tcp',
-                    '--to-ports', str(port),
-                    '-m', 'ttl', '!', '--ttl', '42'  # to prevent infinite loops
-                    )
-
-
-def ipfw_rule_exists(n):
-    argv = ['ipfw', 'list']
-    p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
-    found = False
-    for line in p.stdout:
-        if line.startswith('%05d ' % n):
-            if not ('ipttl 42 setup keep-state' in line
-                    or ('skipto %d' % (n+1)) in line
-                    or 'check-state' in line):
-                log('non-sshuttle ipfw rule: %r\n' % line.strip())
-                raise Fatal('non-sshuttle ipfw rule #%d already exists!' % n)
-            found = True
-    rv = p.wait()
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-    return found
-
-
-_oldctls = {}
-def _fill_oldctls(prefix):
-    argv = ['sysctl', prefix]
-    p = ssubprocess.Popen(argv, stdout = ssubprocess.PIPE)
-    for line in p.stdout:
-        assert(line[-1] == '\n')
-        (k,v) = line[:-1].split(': ', 1)
-        _oldctls[k] = v
-    rv = p.wait()
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-    if not line:
-        raise Fatal('%r returned no data' % (argv,))
-
-
-def _sysctl_set(name, val):
-    argv = ['sysctl', '-w', '%s=%s' % (name, val)]
-    debug1('>> %s\n' % ' '.join(argv))
-    rv = ssubprocess.call(argv, stdout = open('/dev/null', 'w'))
-
-
-_changedctls = []
-def sysctl_set(name, val):
-    PREFIX = 'net.inet.ip'
-    assert(name.startswith(PREFIX + '.'))
-    val = str(val)
-    if not _oldctls:
-        _fill_oldctls(PREFIX)
-    if not (name in _oldctls):
-        debug1('>> No such sysctl: %r\n' % name)
-        return
-    oldval = _oldctls[name]
-    if val != oldval:
-        _changedctls.append(name)
-        return _sysctl_set(name, val)
-    
-
-def ipfw(*args):
-    argv = ['ipfw', '-q'] + list(args)
-    debug1('>> %s\n' % ' '.join(argv))
-    rv = ssubprocess.call(argv)
-    if rv:
-        raise Fatal('%r returned %d' % (argv, rv))
-
-
-def do_ipfw(port, subnets):
-    sport = str(port)
-    xsport = str(port+1)
-
-    # cleanup any existing rules
-    if ipfw_rule_exists(port):
-        ipfw('delete', sport)
-
-    while _changedctls:
-        name = _changedctls.pop()
-        oldval = _oldctls[name]
-        _sysctl_set(name, oldval)
-
-    if subnets:
-        sysctl_set('net.inet.ip.fw.enable', 1)
-        sysctl_set('net.inet.ip.scopedroute', 0)
-
-        ipfw('add', sport, 'check-state', 'ip',
-             'from', 'any', 'to', 'any')
-        
-        # create new subnet entries
-        for swidth,sexclude,snet in sorted(subnets, reverse=True):
-            if sexclude:
-                ipfw('add', sport, 'skipto', xsport,
-                     'log', 'tcp',
-                     'from', 'any', 'to', '%s/%s' % (snet,swidth))
-            else:
-                ipfw('add', sport, 'fwd', '127.0.0.1,%d' % port,
-                     'log', 'tcp',
-                     'from', 'any', 'to', '%s/%s' % (snet,swidth),
-                     'not', 'ipttl', '42', 'keep-state', 'setup')
-
-
-def program_exists(name):
-    paths = (os.getenv('PATH') or os.defpath).split(os.pathsep)
-    for p in paths:
-        fn = '%s/%s' % (p, name)
-        if os.path.exists(fn):
-            return not os.path.isdir(fn) and os.access(fn, os.X_OK)
-
-hostmap = {}
-def rewrite_etc_hosts(port):
-    HOSTSFILE='/etc/hosts'
-    BAKFILE='%s.sbak' % HOSTSFILE
-    APPEND='# sshuttle-firewall-%d AUTOCREATED' % port
-    old_content = ''
-    st = None
-    try:
-        old_content = open(HOSTSFILE).read()
-        st = os.stat(HOSTSFILE)
-    except IOError, e:
-        if e.errno == errno.ENOENT:
-            pass
-        else:
-            raise
-    if old_content.strip() and not os.path.exists(BAKFILE):
-        os.link(HOSTSFILE, BAKFILE)
-    tmpname = "%s.%d.tmp" % (HOSTSFILE, port)
-    f = open(tmpname, 'w')
-    for line in old_content.rstrip().split('\n'):
-        if line.find(APPEND) >= 0:
-            continue
-        f.write('%s\n' % line)
-    for (name,ip) in sorted(hostmap.items()):
-        f.write('%-30s %s\n' % ('%s %s' % (ip,name), APPEND))
-    f.close()
-
-    if st:
-        os.chown(tmpname, st.st_uid, st.st_gid)
-        os.chmod(tmpname, st.st_mode)
-    else:
-        os.chown(tmpname, 0, 0)
-        os.chmod(tmpname, 0644)
-    os.rename(tmpname, HOSTSFILE)
-
-
-def restore_etc_hosts(port):
-    global hostmap
-    hostmap = {}
-    rewrite_etc_hosts(port)
-
-
-# This is some voodoo for setting up the kernel's transparent
-# proxying stuff.  If subnets is empty, we just delete our sshuttle rules;
-# otherwise we delete it, then make them from scratch.
-#
-# This code is supposed to clean up after itself by deleting its rules on
-# exit.  In case that fails, it's not the end of the world; future runs will
-# supercede it in the transproxy list, at least, so the leftover rules
-# are hopefully harmless.
-def main(port):
-    assert(port > 0)
-    assert(port <= 65535)
-
-    if os.getuid() != 0:
-        raise Fatal('you must be root (or enable su/sudo) to set the firewall')
-
-    if program_exists('ipfw'):
-        do_it = do_ipfw
-    elif program_exists('iptables'):
-        do_it = do_iptables
-    else:
-        raise Fatal("can't find either ipfw or iptables; check your PATH")
-
-    # because of limitations of the 'su' command, the *real* stdin/stdout
-    # are both attached to stdout initially.  Clone stdout into stdin so we
-    # can read from it.
-    os.dup2(1, 0)
-
-    debug1('firewall manager ready.\n')
-    sys.stdout.write('READY\n')
-    sys.stdout.flush()
-
-    # ctrl-c shouldn't be passed along to me.  When the main sshuttle dies,
-    # I'll die automatically.
-    os.setsid()
-
-    # we wait until we get some input before creating the rules.  That way,
-    # sshuttle can launch us as early as possible (and get sudo password
-    # authentication as early in the startup process as possible).
-    line = sys.stdin.readline(128)
-    if not line:
-        return  # parent died; nothing to do
-
-    subnets = []
-    if line != 'ROUTES\n':
-        raise Fatal('firewall: expected ROUTES but got %r' % line)
-    while 1:
-        line = sys.stdin.readline(128)
-        if not line:
-            raise Fatal('firewall: expected route but got %r' % line)
-        elif line == 'GO\n':
-            break
-        try:
-            (width,exclude,ip) = line.strip().split(',', 2)
-        except:
-            raise Fatal('firewall: expected route or GO but got %r' % line)
-        subnets.append((int(width), bool(int(exclude)), ip))
-        
-    try:
-        if line:
-            debug1('firewall manager: starting transproxy.\n')
-            do_it(port, subnets)
-            sys.stdout.write('STARTED\n')
-        
-        try:
-            sys.stdout.flush()
-        except IOError:
-            # the parent process died for some reason; he's surely been loud
-            # enough, so no reason to report another error
-            return
-
-        # Now we wait until EOF or any other kind of exception.  We need
-        # to stay running so that we don't need a *second* password
-        # authentication at shutdown time - that cleanup is important!
-        while 1:
-            line = sys.stdin.readline(128)
-            if line.startswith('HOST '):
-                (name,ip) = line[5:].strip().split(',', 1)
-                hostmap[name] = ip
-                rewrite_etc_hosts(port)
-            elif line:
-                raise Fatal('expected EOF, got %r' % line)
-            else:
-                break
-    finally:
-        try:
-            debug1('firewall manager: undoing changes.\n')
-        except:
-            pass
-        do_it(port, [])
-        restore_etc_hosts(port)

flake.lock

@@ -0,0 +1,133 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1740743217,
+        "narHash": "sha256-brsCRzLqimpyhORma84c3W2xPbIidZlIc3JGIuQVSNI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "b27ba4eb322d9d2bf2dc9ada9fd59442f50c8d7c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-24.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "pyproject-build-systems": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "pyproject-nix": [
+          "pyproject-nix"
+        ],
+        "uv2nix": [
+          "uv2nix"
+        ]
+      },
+      "locked": {
+        "lastModified": 1740362541,
+        "narHash": "sha256-S8Mno07MspggOv/xIz5g8hB2b/C5HPiX8E+rXzKY+5U=",
+        "owner": "pyproject-nix",
+        "repo": "build-system-pkgs",
+        "rev": "e151741c848ba92331af91f4e47640a1fb82be19",
+        "type": "github"
+      },
+      "original": {
+        "owner": "pyproject-nix",
+        "repo": "build-system-pkgs",
+        "type": "github"
+      }
+    },
+    "pyproject-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1739758351,
+        "narHash": "sha256-Aoa4dEoC7Hf6+gFVk/SDquZTMFlmlfsgdTWuqQxzePs=",
+        "owner": "pyproject-nix",
+        "repo": "pyproject.nix",
+        "rev": "1329712f7f9af3a8b270764ba338a455b7323811",
+        "type": "github"
+      },
+      "original": {
+        "owner": "pyproject-nix",
+        "repo": "pyproject.nix",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs",
+        "pyproject-build-systems": "pyproject-build-systems",
+        "pyproject-nix": "pyproject-nix",
+        "uv2nix": "uv2nix"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "uv2nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "pyproject-nix": [
+          "pyproject-nix"
+        ]
+      },
+      "locked": {
+        "lastModified": 1740497536,
+        "narHash": "sha256-K+8wsVooqhaqyxuvew3+62mgOfRLJ7whv7woqPU3Ypo=",
+        "owner": "pyproject-nix",
+        "repo": "uv2nix",
+        "rev": "d01fd3a141755ad5d5b93dd9fcbd76d6401f5bac",
+        "type": "github"
+      },
+      "original": {
+        "owner": "pyproject-nix",
+        "repo": "uv2nix",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,117 @@
+{
+  description = "Transparent proxy server that works as a poor man's VPN. Forwards over ssh. Doesn't require admin. Works with Linux and MacOS. Supports DNS tunneling.";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
+    pyproject-nix = {
+      url = "github:pyproject-nix/pyproject.nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    uv2nix = {
+      url = "github:pyproject-nix/uv2nix";
+      inputs.pyproject-nix.follows = "pyproject-nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    pyproject-build-systems = {
+      url = "github:pyproject-nix/build-system-pkgs";
+      inputs.pyproject-nix.follows = "pyproject-nix";
+      inputs.uv2nix.follows = "uv2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+      pyproject-nix,
+      uv2nix,
+      pyproject-build-systems,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        inherit (nixpkgs) lib;
+
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        python = pkgs.python312;
+
+        workspace = uv2nix.lib.workspace.loadWorkspace { workspaceRoot = ./.; };
+
+        # Create package overlay from workspace.
+        overlay = workspace.mkPyprojectOverlay {
+          sourcePreference = "sdist";
+        };
+
+        # Extend generated overlay with build fixups
+        #
+        # Uv2nix can only work with what it has, and uv.lock is missing essential metadata to perform some builds.
+        # This is an additional overlay implementing build fixups.
+        # See:
+        # - https://pyproject-nix.github.io/uv2nix/FAQ.html
+        pyprojectOverrides =
+          final: prev:
+          # Implement build fixups here.
+          # Note that uv2nix is _not_ using Nixpkgs buildPythonPackage.
+          # It's using https://pyproject-nix.github.io/pyproject.nix/build.html
+          let
+            inherit (final) resolveBuildSystem;
+            inherit (builtins) mapAttrs;
+
+            # Build system dependencies specified in the shape expected by resolveBuildSystem
+            # The empty lists below are lists of optional dependencies.
+            #
+            # A package `foo` with specification written as:
+            # `setuptools-scm[toml]` in pyproject.toml would be written as
+            # `foo.setuptools-scm = [ "toml" ]` in Nix
+            buildSystemOverrides = {
+              chardet.setuptools = [ ];
+              colorlog.setuptools = [ ];
+              python-debian.setuptools = [ ];
+              pluggy.setuptools = [ ];
+              pathspec.flit-core = [ ];
+              packaging.flit-core = [ ];
+            };
+
+          in
+          mapAttrs (
+            name: spec:
+            prev.${name}.overrideAttrs (old: {
+              nativeBuildInputs = old.nativeBuildInputs ++ resolveBuildSystem spec;
+            })
+          ) buildSystemOverrides;
+
+        pythonSet =
+          (pkgs.callPackage pyproject-nix.build.packages {
+            inherit python;
+          }).overrideScope
+            (
+              lib.composeManyExtensions [
+                pyproject-build-systems.overlays.default
+                overlay
+                pyprojectOverrides
+              ]
+            );
+
+        inherit (pkgs.callPackages pyproject-nix.build.util { }) mkApplication;
+        package = mkApplication {
+          venv = pythonSet.mkVirtualEnv "sshuttle" workspace.deps.default;
+          package = pythonSet.sshuttle;
+        };
+      in
+      {
+        packages = {
+          sshuttle = package;
+          default = package;
+        };
+        devShells.default = pkgs.mkShell {
+          packages = [
+            pkgs.uv
+          ];
+        };
+      }
+    );
+}

helpers.py

@@ -1,37 +0,0 @@
-import sys, os
-
-logprefix = ''
-verbose = 0
-
-def log(s):
-    try:
-        sys.stdout.flush()
-        sys.stderr.write(logprefix + s)
-        sys.stderr.flush()
-    except IOError:
-        # this could happen if stderr gets forcibly disconnected, eg. because
-        # our tty closes.  That sucks, but it's no reason to abort the program.
-        pass
-
-def debug1(s):
-    if verbose >= 1:
-        log(s)
-
-def debug2(s):
-    if verbose >= 2:
-        log(s)
-
-def debug3(s):
-    if verbose >= 3:
-        log(s)
-
-
-class Fatal(Exception):
-    pass
-
-
-def list_contains_any(l, sub):
-    for i in sub:
-        if i in l:
-            return True
-    return False

hostwatch.py

@@ -1,277 +0,0 @@
-import time, socket, re, select, errno
-if not globals().get('skip_imports'):
-    import compat.ssubprocess as ssubprocess
-    import helpers
-    from helpers import *
-
-POLL_TIME = 60*15
-NETSTAT_POLL_TIME = 30
-CACHEFILE=os.path.expanduser('~/.sshuttle.hosts')
-
-
-_nmb_ok = True
-_smb_ok = True
-hostnames = {}
-queue = {}
-null = open('/dev/null', 'rb+')
-
-
-def _is_ip(s):
-    return re.match(r'\d+\.\d+\.\d+\.\d+$', s)
-
-
-def write_host_cache():
-    tmpname = '%s.%d.tmp' % (CACHEFILE, os.getpid())
-    try:
-        f = open(tmpname, 'wb')
-        for name,ip in sorted(hostnames.items()):
-            f.write('%s,%s\n' % (name, ip))
-        f.close()
-        os.rename(tmpname, CACHEFILE)
-    finally:
-        try:
-            os.unlink(tmpname)
-        except:
-            pass
-
-
-def read_host_cache():
-    try:
-        f = open(CACHEFILE)
-    except IOError, e:
-        if e.errno == errno.ENOENT:
-            return
-        else:
-            raise
-    for line in f:
-        words = line.strip().split(',')
-        if len(words) == 2:
-            (name,ip) = words
-            name = re.sub(r'[^-\w]', '-', name).strip()
-            ip = re.sub(r'[^0-9.]', '', ip).strip()
-            if name and ip:
-                found_host(name, ip)
-                
-
-def found_host(hostname, ip):
-    hostname = re.sub(r'\..*', '', hostname)
-    hostname = re.sub(r'[^-\w]', '_', hostname)
-    if (ip.startswith('127.') or ip.startswith('255.') 
-        or hostname == 'localhost'):
-        return
-    oldip = hostnames.get(hostname)
-    if oldip != ip:
-        hostnames[hostname] = ip
-        debug1('Found: %s: %s\n' % (hostname, ip))
-        sys.stdout.write('%s,%s\n' % (hostname, ip))
-        write_host_cache()
-
-
-def _check_etc_hosts():
-    debug2(' > hosts\n')
-    for line in open('/etc/hosts'):
-        line = re.sub(r'#.*', '', line)
-        words = line.strip().split()
-        if not words:
-            continue
-        ip = words[0]
-        names = words[1:]
-        if _is_ip(ip):
-            debug3('<    %s %r\n' % (ip, names))
-            for n in names:
-                check_host(n)
-                found_host(n, ip)
-
-
-def _check_revdns(ip):
-    debug2(' > rev: %s\n' % ip)
-    try:
-        r = socket.gethostbyaddr(ip)
-        debug3('<    %s\n' % r[0])
-        check_host(r[0])
-        found_host(r[0], ip)
-    except socket.herror, e:
-        pass
-
-
-def _check_dns(hostname):
-    debug2(' > dns: %s\n' % hostname)
-    try:
-        ip = socket.gethostbyname(hostname)
-        debug3('<    %s\n' % ip)
-        check_host(ip)
-        found_host(hostname, ip)
-    except socket.gaierror, e:
-        pass
-
-
-def _check_netstat():
-    debug2(' > netstat\n')
-    argv = ['netstat', '-n']
-    try:
-        p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, stderr=null)
-        content = p.stdout.read()
-        p.wait()
-    except OSError, e:
-        log('%r failed: %r\n' % (argv, e))
-        return
-
-    for ip in re.findall(r'\d+\.\d+\.\d+\.\d+', content):
-        debug3('<    %s\n' % ip)
-        check_host(ip)
-        
-
-def _check_smb(hostname):
-    return
-    global _smb_ok
-    if not _smb_ok:
-        return
-    argv = ['smbclient', '-U', '%', '-L', hostname]
-    debug2(' > smb: %s\n' % hostname)
-    try:
-        p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, stderr=null)
-        lines = p.stdout.readlines()
-        p.wait()
-    except OSError, e:
-        log('%r failed: %r\n' % (argv, e))
-        _smb_ok = False
-        return
-
-    lines.reverse()
-
-    # junk at top
-    while lines:
-        line = lines.pop().strip()
-        if re.match(r'Server\s+', line):
-            break
-
-    # server list section:
-    #    Server   Comment
-    #    ------   -------
-    while lines:
-        line = lines.pop().strip()
-        if not line or re.match(r'-+\s+-+', line):
-            continue
-        if re.match(r'Workgroup\s+Master', line):
-            break
-        words = line.split()
-        hostname = words[0].lower()
-        debug3('<    %s\n' % hostname)
-        check_host(hostname)
-
-    # workgroup list section:
-    #   Workgroup  Master
-    #   ---------  ------
-    while lines:
-        line = lines.pop().strip()
-        if re.match(r'-+\s+', line):
-            continue
-        if not line:
-            break
-        words = line.split()
-        (workgroup, hostname) = (words[0].lower(), words[1].lower())
-        debug3('<    group(%s) -> %s\n' % (workgroup, hostname))
-        check_host(hostname)
-        check_workgroup(workgroup)
-
-    if lines:
-        assert(0)
-
-
-def _check_nmb(hostname, is_workgroup, is_master):
-    return
-    global _nmb_ok
-    if not _nmb_ok:
-        return
-    argv = ['nmblookup'] + ['-M']*is_master + ['--', hostname]
-    debug2(' > n%d%d: %s\n' % (is_workgroup, is_master, hostname))
-    try:
-        p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, stderr=null)
-        lines = p.stdout.readlines()
-        rv = p.wait()
-    except OSError, e:
-        log('%r failed: %r\n' % (argv, e))
-        _nmb_ok = False
-        return
-    if rv:
-        log('%r returned %d\n' % (argv, rv))
-        return
-    for line in lines:
-        m = re.match(r'(\d+\.\d+\.\d+\.\d+) (\w+)<\w\w>\n', line)
-        if m:
-            g = m.groups()
-            (ip, name) = (g[0], g[1].lower())
-            debug3('<    %s -> %s\n' % (name, ip))
-            if is_workgroup:
-                _enqueue(_check_smb, ip)
-            else:
-                found_host(name, ip)
-                check_host(name)
-
-
-def check_host(hostname):
-    if _is_ip(hostname):
-        _enqueue(_check_revdns, hostname)
-    else:
-        _enqueue(_check_dns, hostname)
-    _enqueue(_check_smb, hostname)
-    _enqueue(_check_nmb, hostname, False, False)
-
-
-def check_workgroup(hostname):
-    _enqueue(_check_nmb, hostname, True, False)
-    _enqueue(_check_nmb, hostname, True, True)
-
-
-def _enqueue(op, *args):
-    t = (op,args)
-    if queue.get(t) == None:
-        queue[t] = 0
-
-
-def _stdin_still_ok(timeout):
-    r,w,x = select.select([sys.stdin.fileno()], [], [], timeout)
-    if r:
-        b = os.read(sys.stdin.fileno(), 4096)
-        if not b:
-            return False
-    return True
-
-
-def hw_main(seed_hosts):
-    if helpers.verbose >= 2:
-        helpers.logprefix = 'HH: '
-    else:
-        helpers.logprefix = 'hostwatch: '
-
-    read_host_cache()
-        
-    _enqueue(_check_etc_hosts)
-    _enqueue(_check_netstat)
-    check_host('localhost')
-    check_host(socket.gethostname())
-    check_workgroup('workgroup')
-    check_workgroup('-')
-    for h in seed_hosts:
-        check_host(h)
-
-    while 1:
-        now = time.time()
-        for t,last_polled in queue.items():
-            (op,args) = t
-            if not _stdin_still_ok(0):
-                break
-            maxtime = POLL_TIME
-            if op == _check_netstat:
-                maxtime = NETSTAT_POLL_TIME
-            if now - last_polled > maxtime:
-                queue[t] = time.time()
-                op(*args)
-            try:
-                sys.stdout.flush()
-            except IOError:
-                break
-                
-        # FIXME: use a smarter timeout based on oldest last_polled
-        if not _stdin_still_ok(1):
-            break

main.py

@@ -1,114 +0,0 @@
-#!/usr/bin/env python
-import sys, os, re
-import helpers, options, client, server, firewall, hostwatch
-from helpers import *
-
-
-# list of:
-# 1.2.3.4/5 or just 1.2.3.4
-def parse_subnets(subnets_str):
-    subnets = []
-    for s in subnets_str:
-        m = re.match(r'(\d+)(?:\.(\d+)\.(\d+)\.(\d+))?(?:/(\d+))?$', s)
-        if not m:
-            raise Fatal('%r is not a valid IP subnet format' % s)
-        (a,b,c,d,width) = m.groups()
-        (a,b,c,d) = (int(a or 0), int(b or 0), int(c or 0), int(d or 0))
-        if width == None:
-            width = 32
-        else:
-            width = int(width)
-        if a > 255 or b > 255 or c > 255 or d > 255:
-            raise Fatal('%d.%d.%d.%d has numbers > 255' % (a,b,c,d))
-        if width > 32:
-            raise Fatal('*/%d is greater than the maximum of 32' % width)
-        subnets.append(('%d.%d.%d.%d' % (a,b,c,d), width))
-    return subnets
-
-
-# 1.2.3.4:567 or just 1.2.3.4 or just 567
-def parse_ipport(s):
-    s = str(s)
-    m = re.match(r'(?:(\d+)\.(\d+)\.(\d+)\.(\d+))?(?::)?(?:(\d+))?$', s)
-    if not m:
-        raise Fatal('%r is not a valid IP:port format' % s)
-    (a,b,c,d,port) = m.groups()
-    (a,b,c,d,port) = (int(a or 0), int(b or 0), int(c or 0), int(d or 0),
-                      int(port or 0))
-    if a > 255 or b > 255 or c > 255 or d > 255:
-        raise Fatal('%d.%d.%d.%d has numbers > 255' % (a,b,c,d))
-    if port > 65535:
-        raise Fatal('*:%d is greater than the maximum of 65535' % port)
-    if a == None:
-        a = b = c = d = 0
-    return ('%d.%d.%d.%d' % (a,b,c,d), port)
-
-
-optspec = """
-sshuttle [-l [ip:]port] [-r [username@]sshserver[:port]] <subnets...>
-sshuttle --firewall <port> <subnets...>
-sshuttle --server
---
-l,listen=  transproxy to this ip address and port number [0.0.0.0:0]
-H,auto-hosts scan for remote hostnames and update local /etc/hosts
-N,auto-nets  automatically determine subnets to route
-python= specify the name/path of the python interpreter on the remote server [python]
-r,remote=  ssh hostname (and optional username) of remote sshuttle server
-x,exclude= exclude this subnet (can be used more than once)
-v,verbose  increase debug message verbosity
-e,ssh-cmd= the command to use to connect to the remote [ssh]
-seed-hosts= with -H, use these hostnames for initial scan (comma-separated)
-server     (internal use only)
-firewall   (internal use only)
-hostwatch  (internal use only)
-"""
-o = options.Options('sshuttle', optspec)
-(opt, flags, extra) = o.parse(sys.argv[1:])
-
-helpers.verbose = opt.verbose
-
-try:
-    if opt.server:
-        if len(extra) != 0:
-            o.fatal('no arguments expected')
-        sys.exit(server.main())
-    elif opt.firewall:
-        if len(extra) != 1:
-            o.fatal('exactly one argument expected')
-        sys.exit(firewall.main(int(extra[0])))
-    elif opt.hostwatch:
-        sys.exit(hostwatch.hw_main(extra))
-    else:
-        if len(extra) < 1 and not opt.auto_nets:
-            o.fatal('at least one subnet (or -N) expected')
-        includes = extra
-        excludes = ['127.0.0.0/8']
-        for k,v in flags:
-            if k in ('-x','--exclude'):
-                excludes.append(v)
-        remotename = opt.remote
-        if remotename == '' or remotename == '-':
-            remotename = None
-        if opt.seed_hosts and not opt.auto_hosts:
-            o.fatal('--seed-hosts only works if you also use -H')
-        if opt.seed_hosts:
-            sh = re.split(r'[\s,]+', (opt.seed_hosts or "").strip())
-        elif opt.auto_hosts:
-            sh = []
-        else:
-            sh = None
-        sys.exit(client.main(parse_ipport(opt.listen or '0.0.0.0:0'),
-                             opt.ssh_cmd,
-                             remotename,
-                             opt.python,
-                             sh,
-                             opt.auto_nets,
-                             parse_subnets(includes),
-                             parse_subnets(excludes)))
-except Fatal, e:
-    log('fatal: %s\n' % e)
-    sys.exit(99)
-except KeyboardInterrupt:
-    log('\n')
-    log('Keyboard interrupt: exiting.\n')
-    sys.exit(1)

options.py

@@ -1,201 +0,0 @@
-"""Command-line options parser.
-With the help of an options spec string, easily parse command-line options.
-"""
-import sys, os, textwrap, getopt, re, struct
-
-class OptDict:
-    def __init__(self):
-        self._opts = {}
-
-    def __setitem__(self, k, v):
-        if k.startswith('no-') or k.startswith('no_'):
-            k = k[3:]
-            v = not v
-        self._opts[k] = v
-
-    def __getitem__(self, k):
-        if k.startswith('no-') or k.startswith('no_'):
-            return not self._opts[k[3:]]
-        return self._opts[k]
-
-    def __getattr__(self, k):
-        return self[k]
-
-
-def _default_onabort(msg):
-    sys.exit(97)
-
-
-def _intify(v):
-    try:
-        vv = int(v or '')
-        if str(vv) == v:
-            return vv
-    except ValueError:
-        pass
-    return v
-
-
-def _atoi(v):
-    try:
-        return int(v or 0)
-    except ValueError:
-        return 0
-
-
-def _remove_negative_kv(k, v):
-    if k.startswith('no-') or k.startswith('no_'):
-        return k[3:], not v
-    return k,v
-
-def _remove_negative_k(k):
-    return _remove_negative_kv(k, None)[0]
-
-
-def _tty_width():
-    s = struct.pack("HHHH", 0, 0, 0, 0)
-    try:
-        import fcntl, termios
-        s = fcntl.ioctl(sys.stderr.fileno(), termios.TIOCGWINSZ, s)
-    except (IOError, ImportError):
-        return _atoi(os.environ.get('WIDTH')) or 70
-    (ysize,xsize,ypix,xpix) = struct.unpack('HHHH', s)
-    return xsize
-
-
-class Options:
-    """Option parser.
-    When constructed, two strings are mandatory. The first one is the command
-    name showed before error messages. The second one is a string called an
-    optspec that specifies the synopsis and option flags and their description.
-    For more information about optspecs, consult the bup-options(1) man page.
-
-    Two optional arguments specify an alternative parsing function and an
-    alternative behaviour on abort (after having output the usage string).
-
-    By default, the parser function is getopt.gnu_getopt, and the abort
-    behaviour is to exit the program.
-    """
-    def __init__(self, exe, optspec, optfunc=getopt.gnu_getopt,
-                 onabort=_default_onabort):
-        self.exe = exe
-        self.optspec = optspec
-        self._onabort = onabort
-        self.optfunc = optfunc
-        self._aliases = {}
-        self._shortopts = 'h?'
-        self._longopts = ['help']
-        self._hasparms = {}
-        self._defaults = {}
-        self._usagestr = self._gen_usage()
-
-    def _gen_usage(self):
-        out = []
-        lines = self.optspec.strip().split('\n')
-        lines.reverse()
-        first_syn = True
-        while lines:
-            l = lines.pop()
-            if l == '--': break
-            out.append('%s: %s\n' % (first_syn and 'usage' or '   or', l))
-            first_syn = False
-        out.append('\n')
-        last_was_option = False
-        while lines:
-            l = lines.pop()
-            if l.startswith(' '):
-                out.append('%s%s\n' % (last_was_option and '\n' or '',
-                                       l.lstrip()))
-                last_was_option = False
-            elif l:
-                (flags, extra) = l.split(' ', 1)
-                extra = extra.strip()
-                if flags.endswith('='):
-                    flags = flags[:-1]
-                    has_parm = 1
-                else:
-                    has_parm = 0
-                g = re.search(r'\[([^\]]*)\]$', extra)
-                if g:
-                    defval = g.group(1)
-                else:
-                    defval = None
-                flagl = flags.split(',')
-                flagl_nice = []
-                for f in flagl:
-                    f,dvi = _remove_negative_kv(f, _intify(defval))
-                    self._aliases[f] = _remove_negative_k(flagl[0])
-                    self._hasparms[f] = has_parm
-                    self._defaults[f] = dvi
-                    if len(f) == 1:
-                        self._shortopts += f + (has_parm and ':' or '')
-                        flagl_nice.append('-' + f)
-                    else:
-                        f_nice = re.sub(r'\W', '_', f)
-                        self._aliases[f_nice] = _remove_negative_k(flagl[0])
-                        self._longopts.append(f + (has_parm and '=' or ''))
-                        self._longopts.append('no-' + f)
-                        flagl_nice.append('--' + f)
-                flags_nice = ', '.join(flagl_nice)
-                if has_parm:
-                    flags_nice += ' ...'
-                prefix = '    %-20s  ' % flags_nice
-                argtext = '\n'.join(textwrap.wrap(extra, width=_tty_width(),
-                                                initial_indent=prefix,
-                                                subsequent_indent=' '*28))
-                out.append(argtext + '\n')
-                last_was_option = True
-            else:
-                out.append('\n')
-                last_was_option = False
-        return ''.join(out).rstrip() + '\n'
-
-    def usage(self, msg=""):
-        """Print usage string to stderr and abort."""
-        sys.stderr.write(self._usagestr)
-        e = self._onabort and self._onabort(msg) or None
-        if e:
-            raise e
-
-    def fatal(self, s):
-        """Print an error message to stderr and abort with usage string."""
-        msg = 'error: %s\n' % s
-        sys.stderr.write(msg)
-        return self.usage(msg)
-
-    def parse(self, args):
-        """Parse a list of arguments and return (options, flags, extra).
-
-        In the returned tuple, "options" is an OptDict with known options,
-        "flags" is a list of option flags that were used on the command-line,
-        and "extra" is a list of positional arguments.
-        """
-        try:
-            (flags,extra) = self.optfunc(args, self._shortopts, self._longopts)
-        except getopt.GetoptError, e:
-            self.fatal(e)
-
-        opt = OptDict()
-
-        for k,v in self._defaults.iteritems():
-            k = self._aliases[k]
-            opt[k] = v
-
-        for (k,v) in flags:
-            k = k.lstrip('-')
-            if k in ('h', '?', 'help'):
-                self.usage()
-            if k.startswith('no-'):
-                k = self._aliases[k[3:]]
-                v = 0
-            else:
-                k = self._aliases[k]
-                if not self._hasparms[k]:
-                    assert(v == '')
-                    v = (opt._opts.get(k) or 0) + 1
-                else:
-                    v = _intify(v)
-            opt[k] = v
-        for (f1,f2) in self._aliases.iteritems():
-            opt[f1] = opt._opts.get(f2)
-        return (opt,flags,extra)

pyproject.toml

@@ -0,0 +1,57 @@
+[project]
+authors = [
+    {name = "Brian May", email = "brian@linuxpenguins.xyz"},
+]
+license = {text = "LGPL-2.1"}
+requires-python = "<4.0,>=3.9"
+dependencies = []
+name = "sshuttle"
+version = "1.3.1"
+description = "Transparent proxy server that works as a poor man's VPN. Forwards over ssh. Doesn't require admin. Works with Linux and MacOS. Supports DNS tunneling."
+readme = "README.rst"
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Intended Audience :: Developers",
+    "Intended Audience :: End Users/Desktop",
+    "License :: OSI Approved :: GNU Lesser General Public License v2 or later (LGPLv2+)",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Topic :: System :: Networking",
+]
+
+[project.scripts]
+sshuttle = "sshuttle.cmdline:main"
+
+[dependency-groups]
+dev = [
+    "pytest<9.0.0,>=8.0.1",
+    "pytest-cov<7.0,>=4.1",
+    "flake8<8.0.0,>=7.0.0",
+    "pyflakes<4.0.0,>=3.2.0",
+    "bump2version<2.0.0,>=1.0.1",
+    "twine<7,>=5",
+    "black>=25.1.0",
+    "jedi-language-server>=0.44.0",
+    "pylsp-mypy>=0.7.0",
+    "python-lsp-server>=1.12.2",
+    "ruff>=0.11.2",
+]
+docs = [
+    "sphinx==8.1.3; python_version ~= \"3.10\"",
+    "furo==2024.8.6",
+]
+
+[tool.uv]
+default-groups = []
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.hatch.build.targets.sdist]
+exclude = [
+    "/.jj"
+]

run

@@ -0,0 +1,15 @@
+#!/usr/bin/env sh
+set -e
+export PYTHONPATH="$(dirname "$0"):$PYTHONPATH"
+export PATH="$(dirname "$0")/bin:$PATH"
+
+python_best_version() {
+  if [ -x "$(command -v python3)" ] &&
+      python3 -c "import sys; sys.exit(not sys.version_info > (3, 5))"; then
+    exec python3 "$@"
+  else
+    exec python "$@"
+  fi
+}
+
+python_best_version -m "sshuttle" "$@"

scripts/Containerfile

@@ -0,0 +1,39 @@
+# https://hub.docker.com/r/linuxserver/openssh-server/
+ARG BASE_IMAGE=docker.io/linuxserver/openssh-server:version-9.3_p2-r1
+
+FROM ${BASE_IMAGE} as pyenv
+
+# https://github.com/pyenv/pyenv/wiki#suggested-build-environment
+RUN apk add --no-cache build-base git libffi-dev openssl-dev bzip2-dev zlib-dev readline-dev sqlite-dev
+ENV PYENV_ROOT=/pyenv
+RUN curl https://raw.githubusercontent.com/pyenv/pyenv-installer/master/bin/pyenv-installer | bash
+RUN /pyenv/bin/pyenv install 3.10
+RUN /pyenv/bin/pyenv install 3.11
+RUN /pyenv/bin/pyenv install 3.12
+RUN bash -xc 'rm -rf /pyenv/{.git,plugins} /pyenv/versions/*/lib/*/{test,config,config-*linux-gnu}' && \
+    find /pyenv -type d -name __pycache__ -exec rm -rf {} + && \
+    find /pyenv -type f -name '*.py[co]' -delete
+
+FROM ${BASE_IMAGE}
+
+RUN apk add --no-cache bash nginx iperf3
+
+# pyenv setup
+ENV PYENV_ROOT=/pyenv
+ENV PATH=/pyenv/shims:/pyenv/bin:$PATH
+COPY --from=pyenv /pyenv /pyenv
+
+# OpenSSH Server variables
+ENV PUID=1000
+ENV PGID=1000
+ENV PASSWORD_ACCESS=true
+ENV USER_NAME=test
+ENV USER_PASSWORD=test
+ENV LOG_STDOUT=true
+
+# suppress linuxserver.io logo printing, chnage sshd config
+RUN sed -i '1 a exec &>/dev/null' /etc/s6-overlay/s6-rc.d/init-adduser/run
+
+# https://www.linuxserver.io/blog/2019-09-14-customizing-our-containers
+# To customize the container and start other components 
+COPY container.setup.sh /custom-cont-init.d/setup.sh

scripts/README.md

@@ -0,0 +1,21 @@
+# Container based test bed for sshuttle
+
+```bash
+test-bed up -d # start containers
+
+exec-sshuttle <node-id> [--copy-id] [--server-py=2.7|3.10] [--client-py=2.7|3.10] [--sshuttle-bin=/path/to/sshuttle] [sshuttle-args...]
+    # --copy-id  -> optionally do ssh-copy-id to make it passwordless for future runs
+    # --sshuttle-bin -> use another sshuttle binary instead of one from dev setup
+    # --server-py  -> Python version to use in server. (manged by pyenv)
+    # --client-py -> Python version to use in client (manged by pyenv)
+
+exec-sshuttle node-1 # start sshuttle to connect to node-1
+
+exec-tool curl node-1  # curl to nginx instance running on node1 via IP that is only reachable via sshuttle
+exec-tool iperf3 node-1 # measure throughput to node-1
+
+run-benchmark node-1 --client-py=3.10
+
+```
+
+<https://learn.microsoft.com/en-us/windows-server/administration/openssh/openssh_server_configuration#configuring-the-default-shell-for-openssh-in-windows>

scripts/compose.yml

@@ -0,0 +1,34 @@
+name: sshuttle-testbed
+
+services:
+  node-1:
+    image: ghcr.io/sshuttle/sshuttle-testbed
+    container_name: sshuttle-testbed-node-1
+    hostname: node-1
+    cap_add:
+      - "NET_ADMIN"
+    environment:
+      - ADD_IP_ADDRESSES=10.55.1.77/24
+    networks:
+      default:
+        ipv6_address: 2001:0DB8::551
+  node-2:
+    image: ghcr.io/sshuttle/sshuttle-testbed
+    container_name: sshuttle-testbed-node-2
+    hostname: node-2
+    cap_add:
+      - "NET_ADMIN"
+    environment:
+      - ADD_IP_ADDRESSES=10.55.2.77/32
+    networks:
+      default:
+        ipv6_address: 2001:0DB8::552
+
+networks:
+  default:
+    driver: bridge
+    enable_ipv6: true
+    ipam:
+       config:
+         - subnet: 2001:0DB8::/112
+    # internal: true

scripts/container.setup.sh

@@ -0,0 +1,65 @@
+#!/usr/bin/with-contenv bash
+# shellcheck shell=bash
+
+set -e
+
+function with_set_x() {
+    set -x
+    "$@"
+    {
+        ec=$?
+        set +x
+        return $ec
+    } 2>/dev/null
+}
+
+
+function log() {
+    echo "$*" >&2
+}
+
+log ">>> Setting up $(hostname) | id: $(id)\nIP:\n$(ip a)\nRoutes:\n$(ip r)\npyenv:\n$(pyenv versions)"
+
+echo "
+AcceptEnv PYENV_VERSION
+" >> /etc/ssh/sshd_config
+
+iface="$(ip route | awk '/default/ { print $5 }')"
+default_gw="$(ip route | awk '/default/ { print $3 }')"
+for addr in ${ADD_IP_ADDRESSES//,/ }; do
+    log ">>> Adding $addr to interface $iface"
+    net_addr=$(ipcalc -n "$addr" | awk -F= '{print $2}')
+    with_set_x ip addr add "$addr" dev "$iface"
+    with_set_x ip route add "$net_addr" via "$default_gw" dev "$iface" # so that sshuttle -N can discover routes
+done
+
+log ">>> Starting iperf3 server"
+iperf3 --server --port 5001 &
+
+mkdir -p /www
+echo "<h5>Hello from $(hostname)</h5>
+<pre>
+<u>ip address</u>
+$(ip address)
+<u>ip route</u>
+$(ip route)
+</pre>" >/www/index.html
+echo " 
+daemon off;
+worker_processes 1;
+error_log /dev/stdout info;
+events {
+    worker_connections 1024;
+}
+http {
+    include /etc/nginx/mime.types;
+    server {
+        access_log /dev/stdout;
+        listen 8080 default_server;
+        listen [::]:8080 default_server;
+        root /www;
+    }
+}" >/etc/nginx/nginx.conf
+
+log ">>> Starting nginx"
+nginx &

scripts/exec-sshuttle

@@ -0,0 +1,159 @@
+#!/usr/bin/env bash
+set -e
+
+ export MSYS_NO_PATHCONV=1
+ 
+function with_set_x() {
+    set -x
+    "$@"
+    {
+        ec=$?
+        set +x
+        return $ec
+    } 2>/dev/null
+}
+
+function log() {
+    echo "$*" >&2
+}
+
+ssh_cmd='ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
+ssh_copy_id=false
+args=()
+subnet_args=()
+while [[ $# -gt 0 ]]; do
+    arg=$1
+    shift
+    case "$arg" in
+    -v|-vv*)
+        ssh_cmd+=" -v"
+        args+=("$arg")
+        ;;
+    -r)
+        args+=("-r" "$1")
+        shift
+        ;;
+    --copy-id)
+        ssh_copy_id=true
+        ;;
+    --server-py=*)
+        server_pyenv_ver="${arg#*=}"
+        ;;
+    --client-py=*)
+        client_pyenv_ver="${arg#*=}"
+        ;;
+    -6)
+        ipv6_only=true
+        ;;
+    --sshuttle-bin=*)
+        sshuttle_bin="${arg#*=}"
+        ;;
+    -N|*/*)
+        subnet_args+=("$arg")
+    ;;
+    -*) 
+        args+=("$arg")
+    ;;
+    *)
+        if  [[ -z "$target" ]]; then
+            target=$arg
+        else
+            args+=("$arg")
+        fi
+        ;;
+    esac
+done
+if [[ ${#subnet_args[@]} -eq 0 ]]; then
+    subnet_args=("-N")
+fi
+
+if [[ $target == node-* ]]; then
+    log "Target is a a test-bed node"
+    port="2222"
+    user_part="test:test"
+    host=$("$(dirname "$0")/test-bed" get-ip "$target")
+    index=${target#node-}
+    if [[ $ipv6_only == true ]]; then
+        args+=("2001:0DB8::/112")
+    else
+        args+=("10.55.$index.0/24")
+    fi
+    target="$user_part@$host:$port"
+    if ! command -v sshpass >/dev/null; then
+        log "sshpass is not found. You might have to manually enter ssh password: 'test'"
+    fi
+    if [[ -z $server_pyenv_ver ]]; then
+        log "server-py argumwnt is not specified. Setting it to 3.8"
+        server_pyenv_ver="3.8"
+    fi
+fi
+
+if [[ -n $server_pyenv_ver ]]; then
+    log "Would pass PYENV_VERRSION=$server_pyenv_ver to server. pyenv is required on server to make it work"
+    pycmd="/pyenv/shims/python"
+    ssh_cmd+=" -o SetEnv=PYENV_VERSION=${server_pyenv_ver:-'3'}"
+    args=("--python=$pycmd" "${args[@]}")
+fi
+
+if [[ $ssh_copy_id == true ]]; then
+    log "Trying to make it passwordless"
+    if [[ $target == *@* ]]; then
+        user_part="${target%%@*}"
+        host_part="${target#*@}"
+    else
+        user_part="$(whoami)"
+        host_part="$target"
+    fi
+    if [[ $host_part == *:* ]]; then
+        host="${host_part%:*}"
+        port="${host_part#*:}"
+    else
+        host="$host_part"
+        port="22"
+    fi
+    if [[ $user_part == *:* ]]; then
+        user="${user_part%:*}"
+        password="${user_part#*:}"
+    else
+        user="$user_part"
+        password=""
+    fi
+    cmd=(ssh-copy-id -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p "$port" "$user@$host")
+    if [[ -n $password  ]] && command -v sshpass >/dev/null; then
+        cmd=(sshpass -p "$password" "${cmd[@]}")
+    fi
+    with_set_x "${cmd[@]}"
+fi
+
+if [[ -z $sshuttle_bin || "$sshuttle_bin" == dev ]]; then
+    cd "$(dirname "$0")/.."
+    export PYTHONPATH="."
+    if [[ -n $client_pyenv_ver ]]; then
+        log "Using pyenv version: $client_pyenv_ver"
+        command -v pyenv &>/dev/null || log "You have to install pyenv to use --client-py" && exit 1
+        sshuttle_cmd=(/usr/bin/env PYENV_VERSION="$client_pyenv_ver" pyenv exec python -m sshuttle)
+    else
+        log "Using best python version availble"
+        if [ -x "$(command -v python3)" ] &&
+            python3 -c "import sys; sys.exit(not sys.version_info > (3, 5))"; then
+            sshuttle_cmd=(python3 -m sshuttle)
+        else
+            sshuttle_cmd=(python -m sshuttle)
+        fi
+    fi
+else
+    [[ -n $client_pyenv_ver ]] && log "Can't specify --client-py when --sshuttle-bin is specified" && exit 1
+    sshuttle_cmd=("$sshuttle_bin")
+fi
+
+if [[ " ${args[*]} " != *" --ssh-cmd "* ]]; then
+    args=("--ssh-cmd" "$ssh_cmd" "${args[@]}")
+fi
+
+if [[ " ${args[*]} " != *" -r "* ]]; then
+    args=("-r" "$target" "${args[@]}")
+fi
+
+set -x
+"${sshuttle_cmd[@]}" --version
+exec "${sshuttle_cmd[@]}" "${args[@]}" "${subnet_args[@]}"

scripts/exec-tool

@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+set -e
+
+
+function with_set_x() {
+    set -x
+    "$@"
+    {
+        ec=$?
+        set +x
+        return $ec
+    } 2>/dev/null
+}
+
+function log() {
+    echo "$*" >&2
+}
+
+
+args=()
+while [[ $# -gt 0 ]]; do
+    arg=$1
+    shift
+    case "$arg" in
+    -6)
+        ipv6_only=true
+        continue
+        ;;
+    -*) ;;
+    *)
+        if [[ -z $tool ]]; then
+            tool=$arg
+            continue
+        elif [[ -z $node ]]; then
+            node=$arg
+            continue
+        fi
+        ;;
+    esac
+    args+=("$arg")
+done
+
+tool=${tool?:"tool argument missing. should be one of iperf3,ping,curl,ab"}
+node=${node?:"node argument missing. should be 'node-1' , 'node-2' etc"}
+
+if [[ $node == node-* ]]; then
+    index=${node#node-}
+    if [[ $ipv6_only == true ]]; then
+        host="2001:0DB8::55$index"
+    else
+        host="10.55.$index.77"
+    fi
+else
+    host=$node
+fi
+
+connect_timeout_sec=3
+
+case "$tool" in
+ping)
+    with_set_x exec ping -W $connect_timeout_sec "${args[@]}" "$host"
+    ;;
+iperf3)
+    port=5001
+    with_set_x exec iperf3 --client "$host" --port=$port --connect-timeout=$((connect_timeout_sec * 1000)) "${args[@]}"
+    ;;
+curl)
+    port=8080
+    if [[ $host = *:* ]]; then
+        host="[$host]"
+        args+=(--ipv6)
+    fi
+    with_set_x exec curl "http://$host:$port/" -v --connect-timeout $connect_timeout_sec "${args[@]}"
+    ;;
+ab)
+    port=8080
+    if [[ " ${args[*]}" != *" -n "* && " ${args[*]}" != *" -c "* ]]; then
+        args+=(-n 500 -c 50 "${args[@]}")
+    fi
+    with_set_x exec ab -s $connect_timeout_sec "${args[@]}" "http://$host:$port/"
+    ;;
+*)
+    log "Unknown tool: $tool"
+    exit 2
+    ;;
+esac

scripts/run-benchmark

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+set -e
+cd "$(dirname "$0")"
+
+function with_set_x() {
+    set -x
+    "$@"
+    {
+        ec=$?
+        set +x
+        return $ec
+    } 2>/dev/null
+}
+
+function log() {
+    echo "$*" >&2
+}
+
+./test-bed up -d
+
+benchmark() {
+    log -e "\n======== Benchmarking sshuttle | Args: [$*]  ========"
+    local node=$1
+    shift
+    with_set_x ./exec-sshuttle "$node" --listen 55771 "$@" &
+    sshuttle_pid=$!
+    trap 'kill -0 $sshuttle_pid &>/dev/null && kill -15 $sshuttle_pid' EXIT
+    while ! nc -z localhost 55771; do sleep 0.1; done
+    sleep 1
+    ./exec-tool iperf3 "$node" --time=4
+    with_set_x kill -15 $sshuttle_pid
+    wait $sshuttle_pid || true
+}
+
+if [[ $# -gt 0 ]]; then
+    benchmark "${@}"
+else
+    benchmark node-1 --sshuttle-bin="${SSHUTTLE_BIN:-sshuttle}"
+    benchmark node-1 --sshuttle-bin=dev
+fi

scripts/run-checks

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -e
+cd "$(dirname "$0")/.."
+
+export PYTHONPATH=.
+
+set -x
+python -m flake8 sshuttle tests 
+python -m pytest .

scripts/test-bed

@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+set -e
+cd "$(dirname "$0")"
+
+if [[ -z $1 || $1 = -* ]]; then
+    set -- up "$@"
+fi
+
+function with_set_x() {
+    set -x
+    "$@"
+    {
+        ec=$?
+        set +x
+        return $ec
+    } 2>/dev/null
+}
+
+function build() {
+    # podman build -t ghcr.io/sshuttle/sshuttle-testbed .
+    with_set_x docker build --progress=plain -t ghcr.io/sshuttle/sshuttle-testbed -f Containerfile .
+}
+
+function compose() {
+    # podman-compose "$@"
+    with_set_x docker compose "$@"
+}
+
+function get-ip() {
+    local container_name=sshuttle-testbed-"$1"
+    docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "$container_name"
+}
+
+if [[ $1 == get-ip ]]; then
+    shift
+    get-ip "$@"
+else
+    if [[ $* = *--build* ]]; then
+        build
+    fi
+    compose "$@"
+fi

server.py

@@ -1,175 +0,0 @@
-import re, struct, socket, select, traceback
-if not globals().get('skip_imports'):
-    import ssnet, helpers, hostwatch
-    import compat.ssubprocess as ssubprocess
-    from ssnet import SockWrapper, Handler, Proxy, Mux, MuxWrapper
-    from helpers import *
-
-
-def _ipmatch(ipstr):
-    if ipstr == 'default':
-        ipstr = '0.0.0.0/0'
-    m = re.match(r'^(\d+(\.\d+(\.\d+(\.\d+)?)?)?)(?:/(\d+))?$', ipstr)
-    if m:
-        g = m.groups()
-        ips = g[0]
-        width = int(g[4] or 32)
-        if g[1] == None:
-            ips += '.0.0.0'
-            width = min(width, 8)
-        elif g[2] == None:
-            ips += '.0.0'
-            width = min(width, 16)
-        elif g[3] == None:
-            ips += '.0'
-            width = min(width, 24)
-        return (struct.unpack('!I', socket.inet_aton(ips))[0], width)
-
-
-def _ipstr(ip, width):
-    if width >= 32:
-        return ip
-    else:
-        return "%s/%d" % (ip, width)
-
-
-def _maskbits(netmask):
-    if not netmask:
-        return 32
-    for i in range(32):
-        if netmask[0] & _shl(1, i):
-            return 32-i
-    return 0
-    
-    
-def _shl(n, bits):
-    return n * int(2**bits)
-
-
-def _list_routes():
-    argv = ['netstat', '-rn']
-    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE)
-    routes = []
-    for line in p.stdout:
-        cols = re.split(r'\s+', line)
-        ipw = _ipmatch(cols[0])
-        if not ipw:
-            continue  # some lines won't be parseable; never mind
-        maskw = _ipmatch(cols[2])  # linux only
-        mask = _maskbits(maskw)   # returns 32 if maskw is null
-        width = min(ipw[1], mask)
-        ip = ipw[0] & _shl(_shl(1, width) - 1, 32-width)
-        routes.append((socket.inet_ntoa(struct.pack('!I', ip)), width))
-    rv = p.wait()
-    if rv != 0:
-        log('WARNING: %r returned %d\n' % (argv, rv))
-        log('WARNING: That prevents --auto-nets from working.\n')
-    return routes
-
-
-def list_routes():
-    for (ip,width) in _list_routes():
-        if not ip.startswith('0.') and not ip.startswith('127.'):
-            yield (ip,width)
-
-
-def _exc_dump():
-    exc_info = sys.exc_info()
-    return ''.join(traceback.format_exception(*exc_info))
-
-
-def start_hostwatch(seed_hosts):
-    s1,s2 = socket.socketpair()
-    pid = os.fork()
-    if not pid:
-        # child
-        rv = 99
-        try:
-            try:
-                s2.close()
-                os.dup2(s1.fileno(), 1)
-                os.dup2(s1.fileno(), 0)
-                s1.close()
-                rv = hostwatch.hw_main(seed_hosts) or 0
-            except Exception, e:
-                log('%s\n' % _exc_dump())
-                rv = 98
-        finally:
-            os._exit(rv)
-    s1.close()
-    return pid,s2
-
-
-class Hostwatch:
-    def __init__(self):
-        self.pid = 0
-        self.sock = None
-
-
-def main():
-    if helpers.verbose >= 1:
-        helpers.logprefix = ' s: '
-    else:
-        helpers.logprefix = 'server: '
-
-    routes = list(list_routes())
-    debug1('available routes:\n')
-    for r in routes:
-        debug1('  %s/%d\n' % r)
-        
-    # synchronization header
-    sys.stdout.write('SSHUTTLE0001')
-    sys.stdout.flush()
-
-    handlers = []
-    mux = Mux(socket.fromfd(sys.stdin.fileno(),
-                            socket.AF_INET, socket.SOCK_STREAM),
-              socket.fromfd(sys.stdout.fileno(),
-                            socket.AF_INET, socket.SOCK_STREAM))
-    handlers.append(mux)
-    routepkt = ''
-    for r in routes:
-        routepkt += '%s,%d\n' % r
-    mux.send(0, ssnet.CMD_ROUTES, routepkt)
-
-    hw = Hostwatch()
-    hw.leftover = ''
-        
-    def hostwatch_ready():
-        assert(hw.pid)
-        content = hw.sock.recv(4096)
-        if content:
-            lines = (hw.leftover + content).split('\n')
-            if lines[-1]:
-                # no terminating newline: entry isn't complete yet!
-                hw.leftover = lines.pop()
-                lines.append('')
-            else:
-                hw.leftover = ''
-            mux.send(0, ssnet.CMD_HOST_LIST, '\n'.join(lines))
-        else:
-            raise Fatal('hostwatch process died')
-
-    def got_host_req(data):
-        if not hw.pid:
-            (hw.pid,hw.sock) = start_hostwatch(data.strip().split())
-            handlers.append(Handler(socks = [hw.sock],
-                                    callback = hostwatch_ready))
-    mux.got_host_req = got_host_req
-
-    def new_channel(channel, data):
-        (dstip,dstport) = data.split(',', 1)
-        dstport = int(dstport)
-        outwrap = ssnet.connect_dst(dstip,dstport)
-        handlers.append(Proxy(MuxWrapper(mux, channel), outwrap))
-    mux.new_channel = new_channel
-
-    while mux.ok:
-        if hw.pid:
-            (rpid, rv) = os.waitpid(hw.pid, os.WNOHANG)
-            if rpid:
-                raise Fatal('hostwatch exited unexpectedly: code 0x%04x\n' % rv)
-        
-        ssnet.runonce(handlers, mux)
-        mux.check_fullness()
-        mux.callback()

setup.cfg

@@ -0,0 +1,30 @@
+[bumpversion]
+current_version = 1.3.1
+
+[bumpversion:file:setup.py]
+
+[bumpversion:file:pyproject.toml]
+
+[bumpversion:file:sshuttle/version.py]
+
+[aliases]
+test = pytest
+
+[bdist_wheel]
+universal = 1
+
+[upload]
+sign = true
+identity = 0x1784577F811F6EAC
+
+[flake8]
+count = true
+show-source = true
+statistics = true
+max-line-length = 128
+
+[pycodestyle]
+max-line-length = 128
+
+[tool:pytest]
+addopts = --cov=sshuttle --cov-branch --cov-report=term-missing

ssh.py

@@ -1,95 +0,0 @@
-import sys, os, re, socket, zlib
-import compat.ssubprocess as ssubprocess
-import helpers
-from helpers import *
-
-
-def readfile(name):
-    basedir = os.path.dirname(os.path.abspath(sys.argv[0]))
-    path = [basedir] + sys.path
-    for d in path:
-        fullname = os.path.join(d, name)
-        if os.path.exists(fullname):
-            return open(fullname, 'rb').read()
-    raise Exception("can't find file %r in any of %r" % (name, path))
-
-
-def empackage(z, filename):
-    (path,basename) = os.path.split(filename)
-    content = z.compress(readfile(filename))
-    content += z.flush(zlib.Z_SYNC_FLUSH)
-    return '%s\n%d\n%s' % (basename,len(content), content)
-
-
-def connect(ssh_cmd, rhostport, python):
-    main_exe = sys.argv[0]
-    portl = []
-
-    rhostIsIPv6 = False
-    if (rhostport or '').count(':') > 1:
-        rhostIsIPv6 = True
-        if rhostport.count(']') or rhostport.count('['):
-            result = rhostport.split(']')
-            rhost = result[0].strip('[')
-            if len(result) > 1:
-                result[1] = result[1].strip(':')
-                if result[1] is not '':
-                    portl = ['-p', str(int(result[1]))]
-        else: # can't disambiguate IPv6 colons and a port number. pass the hostname through.
-            rhost = rhostport
-    else: # IPv4
-        l = (rhostport or '').split(':', 1)
-        rhost = l[0]
-        if len(l) > 1:
-            portl = ['-p', str(int(l[1]))]
-
-    if rhost == '-':
-        rhost = None
-
-    ipv6flag = []
-    if rhostIsIPv6:
-        ipv6flag = ['-6']
-
-    z = zlib.compressobj(1)
-    content = readfile('assembler.py')
-    content2 = (empackage(z, 'helpers.py') +
-                empackage(z, 'compat/ssubprocess.py') +
-                empackage(z, 'ssnet.py') +
-                empackage(z, 'hostwatch.py') +
-                empackage(z, 'server.py') +
-                "\n")
-    
-    pyscript = r"""
-                import sys;
-                skip_imports=1;
-                verbosity=%d;
-                exec compile(sys.stdin.read(%d), "assembler.py", "exec")
-                """ % (helpers.verbose or 0, len(content))
-    pyscript = re.sub(r'\s+', ' ', pyscript.strip())
-
-        
-    if not rhost:
-        argv = [python, '-c', pyscript]
-    else:
-        if ssh_cmd:
-            sshl = ssh_cmd.split(' ')
-        else:
-            sshl = ['ssh']
-        argv = (sshl + 
-                portl + 
-                ipv6flag + 
-                [rhost, '--', "'%s' -c '%s'" % (python, pyscript)])
-    (s1,s2) = socket.socketpair()
-    def setup():
-        # runs in the child process
-        s2.close()
-    s1a,s1b = os.dup(s1.fileno()), os.dup(s1.fileno())
-    s1.close()
-    debug2('executing: %r\n' % argv)
-    p = ssubprocess.Popen(argv, stdin=s1a, stdout=s1b, preexec_fn=setup,
-                         close_fds=True)
-    os.close(s1a)
-    os.close(s1b)
-    s2.sendall(content)
-    s2.sendall(content2)
-    return p, s2

sshuttle

@@ -1 +0,0 @@
-main.py

sshuttle.md

@@ -1,223 +0,0 @@
-% sshuttle(8) Sshuttle 0.42
-% Avery Pennarun <apenwarr@gmail.com>
-% 2010-11-09
-
-# NAME
-
-sshuttle - a transparent proxy-based VPN using ssh
-
-# SYNOPSIS
-
-sshuttle [options...] [-r [username@]sshserver[:port]] \<subnets...\>
-
-
-# DESCRIPTION
-
-sshuttle allows you to create a VPN connection from your
-machine to any remote server that you can connect to via
-ssh, as long as that server has python 2.3 or higher.
-
-To work, you must have root access on the local machine,
-but you can have a normal account on the server.
-
-It's valid to run sshuttle more than once simultaneously on
-a single client machine, connecting to a different server
-every time, so you can be on more than one VPN at once.
-
-If run on a router, sshuttle can forward traffic for your
-entire subnet to the VPN.
-
-
-# OPTIONS
-
-\<subnets...\>
-:   a list of subnets to route over the VPN, in the form
-    `a.b.c.d[/width]`.  Valid examples are 1.2.3.4 (a
-    single IP address), 1.2.3.4/32 (equivalent to 1.2.3.4),
-    1.2.3.0/24 (a 24-bit subnet, ie. with a 255.255.255.0
-    netmask), and 0/0 ('just route everything through the
-    VPN').
-
--l, --listen=*[ip:]port*
-:   use this ip address and port number as the transparent
-    proxy port.  By default sshuttle finds an available
-    port automatically, so you don't need to override it.
-
--H, --auto-hosts
-:   scan for remote hostnames and update the local /etc/hosts
-    file with matching entries for as long as the VPN is
-    open.  This is nicer than changing your system's DNS
-    (/etc/resolv.conf) settings, for several reasons.  First,
-    hostnames are added without domain names attached, so
-    you can `ssh thatserver` without worrying if your local
-    domain matches the remote one.  Second, if you sshuttle
-    into more than one VPN at a time, it's impossible to
-    use more than one DNS server at once anyway, but
-    sshuttle correctly merges /etc/hosts entries between
-    all running copies.  Third, if you're only routing a
-    few subnets over the VPN, you probably would prefer to
-    keep using your local DNS server for everything else.
-    
--N, --auto-nets
-:   in addition to the subnets provided on the command
-    line, ask the server which subnets it thinks we should
-    route, and route those automatically.  The suggestions
-    are taken automatically from the server's routing
-    table.
-    
---python
-:   specify the name/path of the remote python interpreter. 
-    The default is just `python`, which means to use the
-    default python interpreter on the remote system's PATH.
-
--r, --remote=*[username@]sshserver[:port]*
-:   the remote hostname and optional username and ssh
-    port number to use for connecting to the remote server. 
-    For example, example.com, testuser@example.com,
-    testuser@example.com:2222, or example.com:2244.
-
--x, --exclude=*subnet*
-:   explicitly exclude this subnet from forwarding.  The
-    format of this option is the same as the `<subnets>`
-    option.  To exclude more than one subnet, specify the
-    `-x` option more than once.  You can say something like
-    `0/0 -x 1.2.3.0/24` to forward everything except the
-    local subnet over the VPN, for example.
-
--v, --verbose
-:   print more information about the session.  This option
-    can be used more than once for increased verbosity.  By
-    default, sshuttle prints only error messages.
-    
--e, --ssh-cmd
-:   the command to use to connect to the remote server. The
-    default is just `ssh`.  Use this if your ssh client is
-    in a non-standard location or you want to provide extra
-    options to the ssh command, for example, `-e 'ssh -v'`.
-
---seed-hosts
-:   a comma-separated list of hostnames to use to
-    initialize the `--auto-hosts` scan algorithm. 
-    `--auto-hosts` does things like poll local SMB servers
-    for lists of local hostnames, but can speed things up
-    if you use this option to give it a few names to start
-    from.
-
---server
-:   (internal use only) run the sshuttle server on
-    stdin/stdout.  This is what the client runs on
-    the remote end.
-
---firewall
-:   (internal use only) run the firewall manager.  This is
-    the only part of sshuttle that must run as root.  If
-    you start sshuttle as a non-root user, it will
-    automatically run `sudo` or `su` to start the firewall
-    manager, but the core of sshuttle still runs as a
-    normal user.
-    
---hostwatch
-:   (internal use only) run the hostwatch daemon.  This
-    process runs on the server side and collects hostnames for
-    the `--auto-hosts` option.  Using this option by itself
-    makes it a lot easier to debug and test the `--auto-hosts`
-    feature.
-
-
-# EXAMPLES
-
-Test locally by proxying all local connections, without using ssh:
-
-    $ sshuttle -v 0/0
-
-    Starting sshuttle proxy.
-    Listening on ('0.0.0.0', 12300).
-    [local sudo] Password: 
-    firewall manager ready.
-    c : connecting to server...
-     s: available routes:
-     s:   192.168.42.0/24
-    c : connected.
-    firewall manager: starting transproxy.
-    c : Accept: '192.168.42.106':50035 -> '192.168.42.121':139.
-    c : Accept: '192.168.42.121':47523 -> '77.141.99.22':443.
-        ...etc...
-    ^C
-    firewall manager: undoing changes.
-    KeyboardInterrupt
-    c : Keyboard interrupt: exiting.
-    c : SW#8:192.168.42.121:47523: deleting
-    c : SW#6:192.168.42.106:50035: deleting
-
-Test connection to a remote server, with automatic hostname
-and subnet guessing:
-
-    $ sshuttle -vNHr example.org
-
-    Starting sshuttle proxy.
-    Listening on ('0.0.0.0', 12300).
-    firewall manager ready.
-    c : connecting to server...
-     s: available routes:
-     s:   77.141.99.0/24
-    c : connected.
-    c : seed_hosts: []
-    firewall manager: starting transproxy.
-    hostwatch: Found: testbox1: 1.2.3.4
-    hostwatch: Found: mytest2: 5.6.7.8
-    hostwatch: Found: domaincontroller: 99.1.2.3
-    c : Accept: '192.168.42.121':60554 -> '77.141.99.22':22.
-    ^C
-    firewall manager: undoing changes.
-    c : Keyboard interrupt: exiting.
-    c : SW#6:192.168.42.121:60554: deleting
-
-
-# DISCUSSION
-
-When it starts, sshuttle creates an ssh session to the
-server specified by the `-r` option.  If `-r` is omitted,
-it will start both its client and server locally, which is
-sometimes useful for testing.
-
-After connecting to the remote server, sshuttle uploads its
-(python) source code to the remote end and executes it
-there.  Thus, you don't need to install sshuttle on the
-remote server, and there are never sshuttle version
-conflicts between client and server.
-
-Unlike most VPNs, sshuttle forwards sessions, not packets. 
-That is, it uses kernel transparent proxying (`iptables
-REDIRECT` rules on Linux, or `ipfw fwd` rules on BSD) to
-capture outgoing TCP sessions, then creates entirely
-separate TCP sessions out to the original destination at
-the other end of the tunnel.
-
-Packet-level forwarding (eg. using the tun/tap devices on
-Linux) seems elegant at first, but it results in
-several problems, notably the 'tcp over tcp' problem.  The
-tcp protocol depends fundamentally on packets being dropped
-in order to implement its congestion control agorithm; if
-you pass tcp packets through a tcp-based tunnel (such as
-ssh), the inner tcp packets will never be dropped, and so
-the inner tcp stream's congestion control will be
-completely broken, and performance will be terrible.  Thus,
-packet-based VPNs (such as IPsec and openvpn) cannot use
-tcp-based encrypted streams like ssh or ssl, and have to
-implement their own encryption from scratch, which is very
-complex and error prone.
-
-sshuttle's simplicity comes from the fact that it can
-safely use the existing ssh encrypted tunnel without
-incurring a performance penalty.  It does this by letting
-the client-side kernel manage the incoming tcp stream, and
-the server-side kernel manage the outgoing tcp stream;
-there is no need for congestion control to be shared
-between the two separate streams, so a tcp-based tunnel is
-fine.
-
-
-# SEE ALSO
-
-`ssh`(1), `python`(1)
-

sshuttle/__init__.py

@@ -0,0 +1 @@
+__version__ = "1.3.1"

sshuttle/__main__.py

@@ -0,0 +1,10 @@
+"""Coverage.py's main entry point."""
+import sys
+import os
+from sshuttle.cmdline import main
+from sshuttle.helpers import debug3
+
+debug3("Start: (pid=%s, ppid=%s) %r" % (os.getpid(), os.getppid(), sys.argv))
+exit_code = main()
+debug3("Exit: (pid=%s, ppid=%s, code=%s) cmd %r" % (os.getpid(), os.getppid(), exit_code, sys.argv))
+sys.exit(exit_code)

sshuttle/assembler.py

@@ -0,0 +1,53 @@
+import sys
+import zlib
+import types
+import platform
+
+stdin = stdin  # type: typing.BinaryIO # noqa: F821 must be a previously defined global
+verbosity = verbosity  # type: int # noqa: F821 must be a previously defined global
+if verbosity > 0:
+    sys.stderr.write(' s: Running server on remote host with %s (version %s)\n'
+                     % (sys.executable, platform.python_version()))
+
+z = zlib.decompressobj()
+
+while 1:
+    name = stdin.readline().strip()
+    if name:
+        # python2 compat: in python2 stdin.readline().strip() -> str
+        #                 in python3 stdin.readline().strip() -> bytes
+        # (see #481)
+        if sys.version_info >= (3, 0):
+            name = name.decode("ASCII")
+        nbytes = int(stdin.readline())
+        if verbosity >= 2:
+            sys.stderr.write(' s: assembling %r (%d bytes)\n'
+                             % (name, nbytes))
+        content = z.decompress(stdin.read(nbytes))
+
+        module = types.ModuleType(name)
+        parents = name.rsplit(".", 1)
+        if len(parents) == 2:
+            parent, parent_name = parents
+            setattr(sys.modules[parent], parent_name, module)
+
+        code = compile(content, name, "exec")
+        exec(code, module.__dict__)  # nosec
+        sys.modules[name] = module
+    else:
+        break
+
+sys.stderr.flush()
+sys.stdout.flush()
+
+# import can only happen once the code has been transferred to
+# the server. 'noqa: E402' excludes these lines from QA checks.
+import sshuttle.helpers  # noqa: E402
+sshuttle.helpers.verbose = verbosity
+
+import sshuttle.cmdline_options as options  # noqa: E402
+from sshuttle.server import main  # noqa: E402
+
+main(options.latency_control, options.latency_buffer_size,
+     options.auto_hosts, options.to_nameserver,
+     options.auto_nets)

sshuttle/cmdline.py

@@ -0,0 +1,145 @@
+import os
+import re
+import shlex
+import socket
+import sys
+import sshuttle.helpers as helpers
+import sshuttle.client as client
+import sshuttle.firewall as firewall
+import sshuttle.hostwatch as hostwatch
+import sshuttle.ssyslog as ssyslog
+from sshuttle.options import parser, parse_ipport
+from sshuttle.helpers import family_ip_tuple, log, Fatal
+from sshuttle.sudoers import sudoers
+from sshuttle.namespace import enter_namespace
+
+
+def main():
+    if 'SSHUTTLE_ARGS' in os.environ:
+        env_args = shlex.split(os.environ['SSHUTTLE_ARGS'])
+    else:
+        env_args = []
+    args = [*env_args, *sys.argv[1:]]
+
+    opt = parser.parse_args(args)
+
+    if opt.sudoers_no_modify:
+        # sudoers() calls exit() when it completes
+        sudoers(user_name=opt.sudoers_user)
+
+    if opt.daemon:
+        opt.syslog = 1
+    if opt.wrap:
+        import sshuttle.ssnet as ssnet
+        ssnet.MAX_CHANNEL = opt.wrap
+    if opt.latency_buffer_size:
+        import sshuttle.ssnet as ssnet
+        ssnet.LATENCY_BUFFER_SIZE = opt.latency_buffer_size
+    helpers.verbose = opt.verbose
+
+    try:
+        # Since namespace and namespace-pid options are only available
+        # in linux, we must check if it exists with getattr
+        namespace = getattr(opt, 'namespace', None)
+        namespace_pid = getattr(opt, 'namespace_pid', None)
+        if namespace or namespace_pid:
+            prefix = helpers.logprefix
+            helpers.logprefix = 'ns: '
+            enter_namespace(namespace, namespace_pid)
+            helpers.logprefix = prefix
+
+        if opt.firewall:
+            if opt.subnets or opt.subnets_file:
+                parser.error('exactly zero arguments expected')
+            return firewall.main(opt.method, opt.syslog)
+        elif opt.hostwatch:
+            hostwatch.hw_main(opt.subnets, opt.auto_hosts)
+            return 0
+        else:
+            # parse_subnetports() is used to create a list of includes
+            # and excludes. It is called once for each parameter and
+            # returns a list of one or more items for each subnet (it
+            # can return more than one item when a hostname in the
+            # parameter resolves to multiple IP addresses. Here, we
+            # flatten these lists.
+            includes = [item for sublist in opt.subnets+opt.subnets_file
+                        for item in sublist]
+            excludes = [item for sublist in opt.exclude for item in sublist]
+
+            if not includes and not opt.auto_nets:
+                parser.error('at least one subnet, subnet file, '
+                             'or -N expected')
+            remotename = opt.remote
+            if remotename == '' or remotename == '-':
+                remotename = None
+            nslist = [family_ip_tuple(ns) for ns in opt.ns_hosts]
+            if opt.seed_hosts:
+                sh = re.split(r'[\s,]+', (opt.seed_hosts or "").strip())
+            elif opt.auto_hosts:
+                sh = []
+            else:
+                sh = None
+            if opt.listen:
+                ipport_v6 = None
+                ipport_v4 = None
+                lst = opt.listen.split(",")
+                for ip in lst:
+                    family, ip, port = parse_ipport(ip)
+                    if family == socket.AF_INET6:
+                        ipport_v6 = (ip, port)
+                    else:
+                        ipport_v4 = (ip, port)
+            else:
+                # parse_ipport4('127.0.0.1:0')
+                ipport_v4 = "auto"
+                # parse_ipport6('[::1]:0')
+                ipport_v6 = "auto" if not opt.disable_ipv6 else None
+            try:
+                int(opt.tmark, 16)
+            except ValueError:
+                parser.error("--tmark must be a hexadecimal value")
+            opt.tmark = opt.tmark.lower()   # make 'x' in 0x lowercase
+            if not opt.tmark.startswith("0x"):  # accept without 0x prefix
+                opt.tmark = "0x%s" % opt.tmark
+            if opt.syslog:
+                ssyslog.start_syslog()
+                ssyslog.close_stdin()
+                ssyslog.stdout_to_syslog()
+                ssyslog.stderr_to_syslog()
+            return_code = client.main(ipport_v6, ipport_v4,
+                                      opt.ssh_cmd,
+                                      remotename,
+                                      opt.python,
+                                      opt.latency_control,
+                                      opt.latency_buffer_size,
+                                      opt.dns,
+                                      nslist,
+                                      opt.method,
+                                      sh,
+                                      opt.auto_hosts,
+                                      opt.auto_nets,
+                                      includes,
+                                      excludes,
+                                      opt.daemon,
+                                      opt.to_ns,
+                                      opt.pidfile,
+                                      opt.user,
+                                      opt.group,
+                                      opt.sudo_pythonpath,
+                                      opt.add_cmd_delimiter,
+                                      opt.remote_shell,
+                                      opt.tmark)
+
+            if return_code == 0:
+                log('Normal exit code, exiting...')
+            else:
+                log('Abnormal exit code %d detected, failing...' % return_code)
+            return return_code
+
+    except Fatal as e:
+        log('fatal: %s' % e)
+        return 99
+    except KeyboardInterrupt:
+        log('\n')
+        log('Keyboard interrupt: exiting.')
+        return 1

sshuttle/firewall.py

@@ -0,0 +1,428 @@
+import errno
+import shutil
+import socket
+import signal
+import sys
+import os
+import platform
+import traceback
+import subprocess as ssubprocess
+import base64
+import io
+
+import sshuttle.ssyslog as ssyslog
+import sshuttle.helpers as helpers
+from sshuttle.helpers import is_admin_user, log, debug1, debug2, debug3, Fatal
+from sshuttle.methods import get_auto_method, get_method
+
+if sys.platform == 'win32':
+    HOSTSFILE = r"C:\Windows\System32\drivers\etc\hosts"
+else:
+    HOSTSFILE = '/etc/hosts'
+sshuttle_pid = None
+
+
+def rewrite_etc_hosts(hostmap, port):
+    BAKFILE = '%s.sbak' % HOSTSFILE
+    APPEND = '# sshuttle-firewall-%d AUTOCREATED' % port
+    old_content = ''
+    st = None
+    try:
+        old_content = open(HOSTSFILE).read()
+        st = os.stat(HOSTSFILE)
+    except IOError as e:
+        if e.errno == errno.ENOENT:
+            pass
+        else:
+            raise
+    if old_content.strip() and not os.path.exists(BAKFILE):
+        try:
+            os.link(HOSTSFILE, BAKFILE)
+        except OSError:
+            # file is locked - performing non-atomic copy
+            shutil.copyfile(HOSTSFILE, BAKFILE)
+    tmpname = "%s.%d.tmp" % (HOSTSFILE, port)
+    f = open(tmpname, 'w')
+    for line in old_content.rstrip().split('\n'):
+        if line.find(APPEND) >= 0:
+            continue
+        f.write('%s\n' % line)
+    for (name, ip) in sorted(hostmap.items()):
+        f.write('%-30s %s\n' % ('%s %s' % (ip, name), APPEND))
+    f.close()
+
+    if sys.platform != 'win32':
+        if st is not None:
+            os.chown(tmpname, st.st_uid, st.st_gid)
+            os.chmod(tmpname, st.st_mode)
+        else:
+            os.chown(tmpname, 0, 0)
+            os.chmod(tmpname, 0o644)
+    try:
+        os.rename(tmpname, HOSTSFILE)
+    except OSError:
+        # file is locked - performing non-atomic copy
+        log('Warning: Using a non-atomic way to overwrite %s that can corrupt the file if '
+            'multiple processes write to it simultaneously.' % HOSTSFILE)
+        shutil.move(tmpname, HOSTSFILE)
+
+
+def restore_etc_hosts(hostmap, port):
+    # Only restore if we added hosts to /etc/hosts previously.
+    if len(hostmap) > 0:
+        debug2('undoing /etc/hosts changes.')
+        rewrite_etc_hosts({}, port)
+
+
+def firewall_exit(signum, frame):
+    # The typical sshuttle exit is that the main sshuttle process
+    # exits, closes file descriptors it uses, and the firewall process
+    # notices that it can't read from stdin anymore and exits
+    # (cleaning up firewall rules).
+    #
+    # However, in some cases, Ctrl+C might get sent to the firewall
+    # process. This might caused if someone manually tries to kill the
+    # firewall process, or if sshuttle was started using sudo's use_pty option
+    # and they try to exit by pressing Ctrl+C. Here, we forward the
+    # Ctrl+C/SIGINT to the main sshuttle process which should trigger
+    # the typical exit process as described above.
+    global sshuttle_pid
+    if sshuttle_pid:
+        debug1("Relaying interupt signal to sshuttle process %d" % sshuttle_pid)
+        if sys.platform == 'win32':
+            sig = signal.CTRL_C_EVENT
+        else:
+            sig = signal.SIGINT
+        os.kill(sshuttle_pid, sig)
+
+
+def _setup_daemon_for_unix_like():
+    if not is_admin_user():
+        raise Fatal('You must have root privileges (or enable su/sudo) to set the firewall')
+
+    # don't disappear if our controlling terminal or stdout/stderr
+    # disappears; we still have to clean up.
+    signal.signal(signal.SIGHUP, signal.SIG_IGN)
+    signal.signal(signal.SIGPIPE, signal.SIG_IGN)
+    signal.signal(signal.SIGTERM, firewall_exit)
+    signal.signal(signal.SIGINT, firewall_exit)
+
+    # Calling setsid() here isn't strictly necessary. However, it forces
+    # Ctrl+C to get sent to the main sshuttle process instead of to
+    # the firewall process---which is our preferred way to shutdown.
+    # Nonetheless, if the firewall process receives a SIGTERM/SIGINT
+    # signal, it will relay a SIGINT to the main sshuttle process
+    # automatically.
+    try:
+        os.setsid()
+    except OSError:
+        # setsid() fails if sudo is configured with the use_pty option.
+        pass
+
+    return sys.stdin.buffer, sys.stdout.buffer
+
+
+def _setup_daemon_for_windows():
+    if not is_admin_user():
+        raise Fatal('You must be administrator to set the firewall')
+
+    signal.signal(signal.SIGTERM, firewall_exit)
+    signal.signal(signal.SIGINT, firewall_exit)
+
+    com_chan = os.environ.get('SSHUTTLE_FW_COM_CHANNEL')
+    if com_chan == 'stdio':
+        debug3('Using inherited stdio for communicating with sshuttle client process')
+    else:
+        debug3('Using shared socket for communicating with sshuttle client process')
+        socket_share_data = base64.b64decode(com_chan)
+        sock = socket.fromshare(socket_share_data)  # type: socket.socket
+        sys.stdin = io.TextIOWrapper(sock.makefile('rb', buffering=0))
+        sys.stdout = io.TextIOWrapper(sock.makefile('wb', buffering=0), write_through=True)
+        sock.close()
+    return sys.stdin.buffer, sys.stdout.buffer
+
+
+# Isolate function that needs to be replaced for tests
+if sys.platform == 'win32':
+    setup_daemon = _setup_daemon_for_windows
+else:
+    setup_daemon = _setup_daemon_for_unix_like
+
+
+# Note that we're sorting in a very particular order:
+# we need to go from smaller, more specific, port ranges, to larger,
+# less-specific, port ranges. At each level, we order by subnet
+# width, from most-specific subnets (largest swidth) to
+# least-specific. On ties, excludes come first.
+# s:(inet, subnet width, exclude flag, subnet, first port, last port)
+def subnet_weight(s):
+    return (-s[-1] + (s[-2] or -65535), s[1], s[2])
+
+
+def flush_systemd_dns_cache():
+    # If the user is using systemd-resolve for DNS resolution, it is
+    # possible for the request to go through systemd-resolve before we
+    # see it...and it may use a cached result instead of sending a
+    # request that we can intercept. When sshuttle starts and stops,
+    # this means that we should clear the cache!
+    #
+    # The command to do this was named systemd-resolve, but changed to
+    # resolvectl in systemd 239.
+    # https://github.com/systemd/systemd/blob/f8eb41003df1a4eab59ff9bec67b2787c9368dbd/NEWS#L3816
+
+    p = None
+    if helpers.which("resolvectl"):
+        debug2("Flushing systemd's DNS resolver cache: "
+               "resolvectl flush-caches")
+        p = ssubprocess.Popen(["resolvectl", "flush-caches"],
+                              stdout=ssubprocess.PIPE, env=helpers.get_env())
+    elif helpers.which("systemd-resolve"):
+        debug2("Flushing systemd's DNS resolver cache: "
+               "systemd-resolve --flush-caches")
+        p = ssubprocess.Popen(["systemd-resolve", "--flush-caches"],
+                              stdout=ssubprocess.PIPE, env=helpers.get_env())
+
+    if p:
+        # Wait so flush is finished and process doesn't show up as defunct.
+        rv = p.wait()
+        if rv != 0:
+            log("Received non-zero return code %d when flushing DNS resolver "
+                "cache." % rv)
+
+
+# This is some voodoo for setting up the kernel's transparent
+# proxying stuff.  If subnets is empty, we just delete our sshuttle rules;
+# otherwise we delete it, then make them from scratch.
+#
+# This code is supposed to clean up after itself by deleting its rules on
+# exit.  In case that fails, it's not the end of the world; future runs will
+# supersede it in the transproxy list, at least, so the leftover rules
+# are hopefully harmless.
+def main(method_name, syslog):
+    helpers.logprefix = 'fw: '
+    stdin, stdout = setup_daemon()
+    hostmap = {}
+    debug1('Starting firewall with Python version %s'
+           % platform.python_version())
+
+    if method_name == "auto":
+        method = get_auto_method()
+    else:
+        method = get_method(method_name)
+
+    if syslog:
+        ssyslog.start_syslog()
+        ssyslog.stderr_to_syslog()
+
+    if not method.is_supported():
+        raise Fatal("The %s method is not supported on this machine. "
+                    "Check that the appropriate programs are in your "
+                    "PATH." % method_name)
+
+    debug1('ready method name %s.' % method.name)
+    stdout.write(('READY %s\n' % method.name).encode('ASCII'))
+    stdout.flush()
+
+    def _read_next_string_line():
+        try:
+            line = stdin.readline(128)
+            if not line:
+                return  # parent probably exited
+            return line.decode('ASCII').strip()
+        except IOError as e:
+            # On windows, ConnectionResetError is thrown when parent process closes it's socket pair end
+            debug3('read from stdin failed: %s' % (e,))
+            return
+    # we wait until we get some input before creating the rules.  That way,
+    # sshuttle can launch us as early as possible (and get sudo password
+    # authentication as early in the startup process as possible).
+    try:
+        line = _read_next_string_line()
+        if not line:
+            return  # parent probably exited
+    except IOError as e:
+        # On windows, ConnectionResetError is thrown when parent process closes it's socket pair end
+        debug3('read from stdin failed: %s' % (e,))
+        return
+
+    subnets = []
+    if line != 'ROUTES':
+        raise Fatal('expected ROUTES but got %r' % line)
+    while 1:
+        line = _read_next_string_line()
+        if not line:
+            raise Fatal('expected route but got %r' % line)
+        elif line.startswith("NSLIST"):
+            break
+        try:
+            (family, width, exclude, ip, fport, lport) = line.split(',', 5)
+        except Exception:
+            raise Fatal('expected route or NSLIST but got %r' % line)
+        subnets.append((
+            int(family),
+            int(width),
+            bool(int(exclude)),
+            ip,
+            int(fport),
+            int(lport)))
+    debug2('Got subnets: %r' % subnets)
+
+    nslist = []
+    if line != 'NSLIST':
+        raise Fatal('expected NSLIST but got %r' % line)
+    while 1:
+        line = _read_next_string_line()
+        if not line:
+            raise Fatal('expected nslist but got %r' % line)
+        elif line.startswith("PORTS "):
+            break
+        try:
+            (family, ip) = line.split(',', 1)
+        except Exception:
+            raise Fatal('expected nslist or PORTS but got %r' % line)
+        nslist.append((int(family), ip))
+        debug2('Got partial nslist: %r' % nslist)
+    debug2('Got nslist: %r' % nslist)
+
+    if not line.startswith('PORTS '):
+        raise Fatal('expected PORTS but got %r' % line)
+    _, _, ports = line.partition(" ")
+    ports = ports.split(",")
+    if len(ports) != 4:
+        raise Fatal('expected 4 ports but got %d' % len(ports))
+    port_v6 = int(ports[0])
+    port_v4 = int(ports[1])
+    dnsport_v6 = int(ports[2])
+    dnsport_v4 = int(ports[3])
+
+    assert port_v6 >= 0
+    assert port_v6 <= 65535
+    assert port_v4 >= 0
+    assert port_v4 <= 65535
+    assert dnsport_v6 >= 0
+    assert dnsport_v6 <= 65535
+    assert dnsport_v4 >= 0
+    assert dnsport_v4 <= 65535
+
+    debug2('Got ports: %d,%d,%d,%d'
+           % (port_v6, port_v4, dnsport_v6, dnsport_v4))
+
+    line = _read_next_string_line()
+    if not line or not line.startswith("GO "):
+        raise Fatal('expected GO but got %r' % line)
+
+    _, _, args = line.partition(" ")
+    global sshuttle_pid
+    udp, user, group, tmark, sshuttle_pid = args.split(" ", 4)
+    udp = bool(int(udp))
+    sshuttle_pid = int(sshuttle_pid)
+    if user == '-':
+        user = None
+    if group == '-':
+        group = None
+    debug2('Got udp: %r, user: %r, group: %r, tmark: %s, sshuttle_pid: %d' %
+           (udp, user, group, tmark, sshuttle_pid))
+
+    subnets_v6 = [i for i in subnets if i[0] == socket.AF_INET6]
+    nslist_v6 = [i for i in nslist if i[0] == socket.AF_INET6]
+    subnets_v4 = [i for i in subnets if i[0] == socket.AF_INET]
+    nslist_v4 = [i for i in nslist if i[0] == socket.AF_INET]
+
+    try:
+        debug1('setting up.')
+
+        if subnets_v6 or nslist_v6:
+            debug2('setting up IPv6.')
+            method.setup_firewall(
+                port_v6, dnsport_v6, nslist_v6,
+                socket.AF_INET6, subnets_v6, udp,
+                user, group, tmark)
+
+        if subnets_v4 or nslist_v4:
+            debug2('setting up IPv4.')
+            method.setup_firewall(
+                port_v4, dnsport_v4, nslist_v4,
+                socket.AF_INET, subnets_v4, udp,
+                user, group, tmark)
+
+        try:
+            # For some methods (eg: windivert) firewall setup will be differed / will run asynchronously.
+            # Such method implements wait_for_firewall_ready() to wait until firewall is up and running.
+            method.wait_for_firewall_ready(sshuttle_pid)
+        except NotImplementedError:
+            pass
+
+        if sys.platform == 'linux':
+            flush_systemd_dns_cache()
+
+        try:
+            stdout.write(b'STARTED\n')
+            stdout.flush()
+        except IOError as e:  # the parent process probably died
+            debug3('write to stdout failed: %s' % (e,))
+            return
+
+        # Now we wait until EOF or any other kind of exception.  We need
+        # to stay running so that we don't need a *second* password
+        # authentication at shutdown time - that cleanup is important!
+        while 1:
+            line = _read_next_string_line()
+            if not line:
+                return
+            if line.startswith('HOST '):
+                (name, ip) = line[5:].split(',', 1)
+                hostmap[name] = ip
+                debug2('setting up /etc/hosts.')
+                rewrite_etc_hosts(hostmap, port_v6 or port_v4)
+            elif line:
+                if not method.firewall_command(line):
+                    raise Fatal('expected command, got %r' % line)
+            else:
+                break
+    finally:
+        try:
+            debug1('undoing changes.')
+        except Exception:
+            debug2('An error occurred, ignoring it.')
+
+        try:
+            if subnets_v6 or nslist_v6:
+                debug2('undoing IPv6 changes.')
+                method.restore_firewall(port_v6, socket.AF_INET6, udp, user, group)
+        except Exception:
+            try:
+                debug1("Error trying to undo IPv6 firewall.")
+                debug1(traceback.format_exc())
+            except Exception:
+                debug2('An error occurred, ignoring it.')
+
+        try:
+            if subnets_v4 or nslist_v4:
+                debug2('undoing IPv4 changes.')
+                method.restore_firewall(port_v4, socket.AF_INET, udp, user, group)
+        except Exception:
+            try:
+                debug1("Error trying to undo IPv4 firewall.")
+                debug1(traceback.format_exc())
+            except Exception:
+                debug2('An error occurred, ignoring it.')
+
+        try:
+            # debug2() message printed in restore_etc_hosts() function.
+            restore_etc_hosts(hostmap, port_v6 or port_v4)
+        except Exception:
+            try:
+                debug1("Error trying to undo /etc/hosts changes.")
+                debug1(traceback.format_exc())
+            except Exception:
+                debug2('An error occurred, ignoring it.')
+
+        if sys.platform == 'linux':
+            try:
+                flush_systemd_dns_cache()
+            except Exception:
+                try:
+                    debug1("Error trying to flush systemd dns cache.")
+                    debug1(traceback.format_exc())
+                except Exception:
+                    debug2("An error occurred, ignoring it.")

sshuttle/helpers.py

@@ -0,0 +1,349 @@
+import sys
+import socket
+import errno
+import os
+import threading
+import subprocess
+import traceback
+import re
+
+if sys.platform != "win32":
+    import fcntl
+
+logprefix = ''
+verbose = 0
+
+
+def b(s):
+    return s.encode("ASCII")
+
+
+def get_verbose_level():
+    return verbose
+
+
+def log(s):
+    global logprefix
+    try:
+        sys.stdout.flush()
+    except (IOError, ValueError):  # ValueError ~ I/O operation on closed file
+        pass
+    try:
+        # Put newline at end of string if line doesn't have one.
+        if not s.endswith("\n"):
+            s = s+"\n"
+
+        prefix = logprefix
+        s = s.rstrip("\n")
+        for line in s.split("\n"):
+            sys.stderr.write(prefix + line + "\n")
+            prefix = "    "
+        sys.stderr.flush()
+    except (IOError, ValueError):  # ValueError ~ I/O operation on closed file
+        # this could happen if stderr gets forcibly disconnected, eg. because
+        # our tty closes.  That sucks, but it's no reason to abort the program.
+        pass
+
+
+def debug1(s):
+    if verbose >= 1:
+        log(s)
+
+
+def debug2(s):
+    if verbose >= 2:
+        log(s)
+
+
+def debug3(s):
+    if verbose >= 3:
+        log(s)
+
+
+class Fatal(Exception):
+    pass
+
+
+def resolvconf_nameservers(systemd_resolved):
+    """Retrieves a list of tuples (address type, address as a string) of
+    the DNS servers used by the system to resolve hostnames.
+
+    If parameter is False, DNS servers are retrieved from only
+    /etc/resolv.conf. This behavior makes sense for the sshuttle
+    server.
+
+    If parameter is True, we retrieve information from both
+    /etc/resolv.conf and /run/systemd/resolve/resolv.conf (if it
+    exists). This behavior makes sense for the sshuttle client.
+
+    """
+
+    # Historically, we just needed to read /etc/resolv.conf.
+    #
+    # If systemd-resolved is active, /etc/resolv.conf will point to
+    # localhost and the actual DNS servers that systemd-resolved uses
+    # are stored in /run/systemd/resolve/resolv.conf. For programs
+    # that use the localhost DNS server, having sshuttle read
+    # /etc/resolv.conf is sufficient. However, resolved provides other
+    # ways of resolving hostnames (such as via dbus) that may not
+    # route requests through localhost. So, we retrieve a list of DNS
+    # servers that resolved uses so we can intercept those as well.
+    #
+    # For more information about systemd-resolved, see:
+    # https://www.freedesktop.org/software/systemd/man/systemd-resolved.service.html
+    #
+    # On machines without systemd-resolved, we expect opening the
+    # second file will fail.
+    files = ['/etc/resolv.conf']
+    if systemd_resolved:
+        files += ['/run/systemd/resolve/resolv.conf']
+
+    nsservers = []
+    for f in files:
+        this_file_nsservers = []
+        try:
+            for line in open(f):
+                words = line.lower().split()
+                if len(words) >= 2 and words[0] == 'nameserver':
+                    this_file_nsservers.append(family_ip_tuple(words[1]))
+            debug2("Found DNS servers in %s: %s" %
+                   (f, [n[1] for n in this_file_nsservers]))
+            nsservers += this_file_nsservers
+        except OSError as e:
+            debug3("Failed to read %s when looking for DNS servers: %s" %
+                   (f, e.strerror))
+
+    return nsservers
+
+
+def windows_nameservers():
+    out = subprocess.check_output(["powershell", "-NonInteractive", "-NoProfile", "-Command", "Get-DnsClientServerAddress"],
+                                  encoding="utf-8")
+    servers = set()
+    for line in out.splitlines():
+        if line.startswith("Loopback "):
+            continue
+        m = re.search(r'{.+}', line)
+        if not m:
+            continue
+        for s in m.group().strip('{}').split(','):
+            s = s.strip()
+            if s.startswith('fec0:0:0:ffff'):
+                continue
+            servers.add(s)
+    debug2("Found DNS servers: %s" % servers)
+    return [(socket.AF_INET6 if ':' in s else socket.AF_INET, s) for s in servers]
+
+
+def get_random_nameserver():
+    """Return a random nameserver selected from servers produced by
+    resolvconf_nameservers()/windows_nameservers()
+    """
+    if sys.platform == "win32":
+        if globals().get('_nameservers') is None:
+            ns_list = windows_nameservers()
+            globals()['_nameservers'] = ns_list
+        else:
+            ns_list = globals()['_nameservers']
+    else:
+        ns_list = resolvconf_nameservers(systemd_resolved=False)
+    if ns_list:
+        if len(ns_list) > 1:
+            # don't import this unless we really need it
+            import random
+            random.shuffle(ns_list)
+        return ns_list[0]
+    else:
+        return (socket.AF_INET, '127.0.0.1')
+
+
+def islocal(ip, family):
+    sock = socket.socket(family)
+    try:
+        try:
+            sock.bind((ip, 0))
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            if e.args[0] == errno.EADDRNOTAVAIL:
+                return False  # not a local IP
+            else:
+                raise
+    finally:
+        sock.close()
+    return True  # it's a local IP, or there would have been an error
+
+
+def family_ip_tuple(ip):
+    if ':' in ip:
+        return (socket.AF_INET6, ip)
+    else:
+        return (socket.AF_INET, ip)
+
+
+def family_to_string(family):
+    if family == socket.AF_INET6:
+        return "AF_INET6"
+    elif family == socket.AF_INET:
+        return "AF_INET"
+    else:
+        return str(family)
+
+
+def get_env():
+    """An environment for sshuttle subprocesses. See get_path()."""
+    env = {
+        'PATH': get_path(),
+        'LC_ALL': "C",
+    }
+    return env
+
+
+def get_path():
+    """Returns a string of paths separated by os.pathsep.
+
+    Users might not have all of the programs sshuttle needs in their
+    PATH variable (i.e., some programs might be in /sbin). Use PATH
+    and a hardcoded set of paths to search through. This function is
+    used by our which() and get_env() functions. If which() and the
+    subprocess environments differ, programs that which() finds might
+    not be found at run time (or vice versa).
+    """
+    path = []
+    if "PATH" in os.environ:
+        path += os.environ["PATH"].split(os.pathsep)
+    # Python default paths.
+    path += os.defpath.split(os.pathsep)
+    # /sbin, etc are not in os.defpath and may not be in PATH either.
+    # /bin/ and /usr/bin below are probably redundant.
+    path += ['/bin', '/usr/bin', '/sbin', '/usr/sbin']
+
+    # Remove duplicates. Not strictly necessary.
+    path_dedup = []
+    for i in path:
+        if i not in path_dedup:
+            path_dedup.append(i)
+
+    return os.pathsep.join(path_dedup)
+
+
+if sys.version_info >= (3, 3):
+    from shutil import which as _which
+else:
+    # Although sshuttle does not officially support older versions of
+    # Python, some still run the sshuttle server on remote machines
+    # with old versions of python.
+    def _which(file, mode=os.F_OK | os.X_OK, path=None):
+        if path is not None:
+            search_paths = path.split(os.pathsep)
+        elif "PATH" in os.environ:
+            search_paths = os.environ["PATH"].split(os.pathsep)
+        else:
+            search_paths = os.defpath.split(os.pathsep)
+
+        for p in search_paths:
+            filepath = os.path.join(p, file)
+            if os.path.exists(filepath) and os.access(filepath, mode):
+                return filepath
+        return None
+
+
+def which(file, mode=os.F_OK | os.X_OK):
+    """A wrapper around shutil.which() that searches a predictable set of
+    paths and is more verbose about what is happening. See get_path()
+    for more information.
+    """
+    path = get_path()
+    rv = _which(file, mode, path)
+    if rv:
+        debug2("which() found '%s' at %s" % (file, rv))
+    else:
+        debug2("which() could not find '%s' in %s" % (file, path))
+    return rv
+
+
+def is_admin_user():
+    if sys.platform == 'win32':
+        # https://stackoverflow.com/questions/130763/request-uac-elevation-from-within-a-python-script/41930586#41930586
+        import ctypes
+        try:
+            return ctypes.windll.shell32.IsUserAnAdmin()
+        except Exception:
+            return False
+
+    # TODO(nom3ad): for sys.platform == 'linux', check capabilities for non-root users. (CAP_NET_ADMIN might be enough?)
+    return os.getuid() == 0
+
+
+def set_non_blocking_io(fd):
+    if sys.platform != "win32":
+        try:
+            os.set_blocking(fd, False)
+        except AttributeError:
+            # python < 3.5
+            flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+            flags |= os.O_NONBLOCK
+            fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+    else:
+        _sock = socket.fromfd(fd, socket.AF_INET, socket.SOCK_STREAM)
+        _sock.setblocking(False)
+
+
+class RWPair:
+    def __init__(self, r, w):
+        self.r = r
+        self.w = w
+        self.read = r.read
+        self.readline = r.readline
+        self.write = w.write
+        self.flush = w.flush
+
+    def close(self):
+        for f in self.r, self.w:
+            try:
+                f.close()
+            except Exception:
+                pass
+
+
+class SocketRWShim:
+    __slots__ = ('_r', '_w', '_on_end', '_s1', '_s2', '_t1', '_t2')
+
+    def __init__(self, r, w, on_end=None):
+        self._r = r
+        self._w = w
+        self._on_end = on_end
+
+        self._s1, self._s2 = socket.socketpair()
+        debug3("[SocketShim] r=%r w=%r | s1=%r s2=%r" % (self._r, self._w, self._s1, self._s2))
+
+        def stream_reader_to_sock():
+            try:
+                for data in iter(lambda:  self._r.read(16384), b''):
+                    self._s1.sendall(data)
+                    # debug3("[SocketRWShim] <<<<< r.read() %d %r..." % (len(data), data[:min(32, len(data))]))
+            except Exception:
+                traceback.print_exc(file=sys.stderr)
+            finally:
+                debug2("[SocketRWShim] Thread 'stream_reader_to_sock' exiting")
+                self._s1.close()
+                self._on_end and self._on_end()
+
+        def stream_sock_to_writer():
+            try:
+                for data in iter(lambda: self._s1.recv(16384), b''):
+                    while data:
+                        n = self._w.write(data)
+                        data = data[n:]
+                    # debug3("[SocketRWShim] <<<<< w.write() %d %r..." % (len(data), data[:min(32, len(data))]))
+            except Exception:
+                traceback.print_exc(file=sys.stderr)
+            finally:
+                debug2("[SocketRWShim] Thread 'stream_sock_to_writer' exiting")
+                self._s1.close()
+                self._on_end and self._on_end()
+
+        self._t1 = threading.Thread(target=stream_reader_to_sock,  name='stream_reader_to_sock', daemon=True).start()
+        self._t2 = threading.Thread(target=stream_sock_to_writer, name='stream_sock_to_writer',  daemon=True).start()
+
+    def makefiles(self):
+        return self._s2.makefile("rb", buffering=0), self._s2.makefile("wb", buffering=0)

sshuttle/hostwatch.py

@@ -0,0 +1,250 @@
+import time
+import socket
+import re
+import select
+import errno
+import os
+import sys
+import platform
+
+import subprocess as ssubprocess
+import sshuttle.helpers as helpers
+from sshuttle.helpers import log, debug1, debug2, debug3, get_env
+
+POLL_TIME = 60 * 15
+NETSTAT_POLL_TIME = 30
+CACHEFILE = os.path.expanduser('~/.sshuttle.hosts')
+
+# Have we already failed to write CACHEFILE?
+CACHE_WRITE_FAILED = False
+
+SHOULD_WRITE_CACHE = False
+
+hostnames = {}
+queue = {}
+try:
+    null = open(os.devnull, 'wb')
+except IOError:
+    _, e = sys.exc_info()[:2]
+    log('warning: %s' % e)
+    null = os.popen("sh -c 'while read x; do :; done'", 'wb', 4096)
+
+
+def _is_ip(s):
+    return re.match(r'\d+\.\d+\.\d+\.\d+$', s)
+
+
+def write_host_cache():
+    """If possible, write our hosts file to disk so future connections
+       can reuse the hosts that we already found."""
+    tmpname = '%s.%d.tmp' % (CACHEFILE, os.getpid())
+    global CACHE_WRITE_FAILED
+    try:
+        f = open(tmpname, 'wb')
+        for name, ip in sorted(hostnames.items()):
+            f.write(('%s,%s\n' % (name, ip)).encode("ASCII"))
+        f.close()
+        os.chmod(tmpname, 384)  # 600 in octal, 'rw-------'
+        os.rename(tmpname, CACHEFILE)
+        CACHE_WRITE_FAILED = False
+    except (OSError, IOError):
+        # Write message if we haven't yet or if we get a failure after
+        # a previous success.
+        if not CACHE_WRITE_FAILED:
+            log("Failed to write host cache to temporary file "
+                "%s and rename it to %s" % (tmpname, CACHEFILE))
+            CACHE_WRITE_FAILED = True
+
+        try:
+            os.unlink(tmpname)
+        except Exception:
+            pass
+
+
+def read_host_cache():
+    """If possible, read the cache file from disk to populate hosts that
+       were found in a previous sshuttle run."""
+    try:
+        f = open(CACHEFILE)
+    except (OSError, IOError):
+        _, e = sys.exc_info()[:2]
+        if e.errno == errno.ENOENT:
+            return
+        else:
+            log("Failed to read existing host cache file %s on remote host"
+                % CACHEFILE)
+            return
+    for line in f:
+        words = line.strip().split(',')
+        if len(words) == 2:
+            (name, ip) = words
+            name = re.sub(r'[^-\w\.]', '-', name).strip()
+            # Remove characters that shouldn't be in IP
+            ip = re.sub(r'[^0-9.]', '', ip).strip()
+            if name and ip:
+                found_host(name, ip)
+    f.close()
+    global SHOULD_WRITE_CACHE
+    if SHOULD_WRITE_CACHE:
+        write_host_cache()
+        SHOULD_WRITE_CACHE = False
+
+
+def found_host(name, ip):
+    """The provided name maps to the given IP. Add the host to the
+       hostnames list, send the host to the sshuttle client via
+       stdout, and write the host to the cache file.
+    """
+    hostname = re.sub(r'\..*', '', name)
+    hostname = re.sub(r'[^-\w\.]', '_', hostname)
+    if (ip.startswith('127.') or ip.startswith('255.') or
+            hostname == 'localhost'):
+        return
+
+    if hostname != name:
+        found_host(hostname, ip)
+
+    global SHOULD_WRITE_CACHE
+    oldip = hostnames.get(name)
+    if oldip != ip:
+        hostnames[name] = ip
+        debug1('Found: %s: %s' % (name, ip))
+        sys.stdout.write('%s,%s\n' % (name, ip))
+        SHOULD_WRITE_CACHE = True
+
+
+def _check_etc_hosts():
+    """If possible, read /etc/hosts to find hosts."""
+    filename = '/etc/hosts'
+    debug2(' > Reading %s on remote host' % filename)
+    try:
+        for line in open(filename):
+            line = re.sub(r'#.*', '', line)  # remove comments
+            words = line.strip().split()
+            if not words:
+                continue
+            ip = words[0]
+            if _is_ip(ip):
+                names = words[1:]
+                debug3('<    %s %r' % (ip, names))
+                for n in names:
+                    check_host(n)
+                    found_host(n, ip)
+    except (OSError, IOError):
+        debug1("Failed to read %s on remote host" % filename)
+
+
+def _check_revdns(ip):
+    """Use reverse DNS to try to get hostnames from an IP addresses."""
+    debug2(' > rev: %s' % ip)
+    try:
+        r = socket.gethostbyaddr(ip)
+        debug3('<    %s' % r[0])
+        check_host(r[0])
+        found_host(r[0], ip)
+    except (OSError, socket.error, UnicodeError):
+        # This case is expected to occur regularly.
+        # debug3('<    %s gethostbyaddr failed on remote host' % ip)
+        pass
+
+
+def _check_dns(hostname):
+    debug2(' > dns: %s' % hostname)
+    try:
+        ip = socket.gethostbyname(hostname)
+        debug3('<    %s' % ip)
+        check_host(ip)
+        found_host(hostname, ip)
+    except (socket.gaierror, UnicodeError):
+        pass
+
+
+def _check_netstat():
+    debug2(' > netstat')
+    argv = ['netstat', '-n']
+    try:
+        p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, stderr=null,
+                              env=get_env())
+        content = p.stdout.read().decode("ASCII")
+        p.wait()
+    except OSError:
+        _, e = sys.exc_info()[:2]
+        log('%r failed: %r' % (argv, e))
+        return
+
+    # The same IPs may appear multiple times. Consolidate them so the
+    # debug message doesn't print the same IP repeatedly.
+    ip_list = []
+    for ip in re.findall(r'\d+\.\d+\.\d+\.\d+', content):
+        if ip not in ip_list:
+            ip_list.append(ip)
+
+    for ip in sorted(ip_list):
+        debug3('<    %s' % ip)
+        check_host(ip)
+
+
+def check_host(hostname):
+    if _is_ip(hostname):
+        _enqueue(_check_revdns, hostname)
+    else:
+        _enqueue(_check_dns, hostname)
+
+
+def _enqueue(op, *args):
+    t = (op, args)
+    if queue.get(t) is None:
+        queue[t] = 0
+
+
+def _stdin_still_ok(timeout):
+    r, _, _ = select.select([sys.stdin.fileno()], [], [], timeout)
+    if r:
+        b = os.read(sys.stdin.fileno(), 4096)
+        if not b:
+            return False
+    return True
+
+
+def hw_main(seed_hosts, auto_hosts):
+    helpers.logprefix = 'HH: '
+
+    debug1('Starting hostwatch with Python version %s'
+           % platform.python_version())
+
+    for h in seed_hosts:
+        check_host(h)
+
+    if auto_hosts:
+        read_host_cache()
+        _enqueue(_check_etc_hosts)
+        _enqueue(_check_netstat)
+        check_host('localhost')
+        check_host(socket.gethostname())
+
+    while 1:
+        now = time.time()
+        # For each item in the queue
+        for t, last_polled in list(queue.items()):
+            (op, args) = t
+            if not _stdin_still_ok(0):
+                break
+
+            # Determine if we need to run.
+            maxtime = POLL_TIME
+            # netstat runs more often than other jobs
+            if op == _check_netstat:
+                maxtime = NETSTAT_POLL_TIME
+
+            # Check if this jobs needs to run.
+            if now - last_polled > maxtime:
+                queue[t] = time.time()
+                op(*args)
+            try:
+                sys.stdout.flush()
+            except IOError:
+                break
+
+        # FIXME: use a smarter timeout based on oldest last_polled
+        if not _stdin_still_ok(1):  # sleeps for up to 1 second
+            break

sshuttle/linux.py

@@ -0,0 +1,51 @@
+import socket
+import subprocess as ssubprocess
+from sshuttle.helpers import log, debug1, Fatal, family_to_string, get_env
+
+
+def nonfatal(func, *args):
+    try:
+        func(*args)
+    except Fatal as e:
+        log('error: %s' % e)
+
+
+def ipt_chain_exists(family, table, name):
+    if family == socket.AF_INET6:
+        cmd = 'ip6tables'
+    elif family == socket.AF_INET:
+        cmd = 'iptables'
+    else:
+        raise Exception('Unsupported family "%s"' % family_to_string(family))
+    argv = [cmd, '-w', '-t', table, '-nL']
+    try:
+        output = ssubprocess.check_output(argv, env=get_env())
+        for line in output.decode('ASCII', errors='replace').split('\n'):
+            if line.startswith('Chain %s ' % name):
+                return True
+    except ssubprocess.CalledProcessError as e:
+        raise Fatal('%r returned %d' % (argv, e.returncode))
+
+
+def ipt(family, table, *args):
+    if family == socket.AF_INET6:
+        argv = ['ip6tables', '-w', '-t', table] + list(args)
+    elif family == socket.AF_INET:
+        argv = ['iptables', '-w', '-t', table] + list(args)
+    else:
+        raise Exception('Unsupported family "%s"' % family_to_string(family))
+    debug1('%s' % ' '.join(argv))
+    rv = ssubprocess.call(argv, env=get_env())
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+
+
+def nft(family, table, action, *args):
+    if family in (socket.AF_INET, socket.AF_INET6):
+        argv = ['nft', action, 'inet', table] + list(args)
+    else:
+        raise Exception('Unsupported family "%s"' % family_to_string(family))
+    debug1('%s' % ' '.join(argv))
+    rv = ssubprocess.call(argv, env=get_env())
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))

sshuttle/methods/__init__.py

@@ -0,0 +1,126 @@
+import importlib
+import socket
+import struct
+import sys
+import errno
+import ipaddress
+from sshuttle.helpers import Fatal, debug3
+
+
+def original_dst(sock):
+    try:
+        family = sock.family
+        SO_ORIGINAL_DST = 80
+
+        if family == socket.AF_INET:
+            SOCKADDR_MIN = 16
+            sockaddr_in = sock.getsockopt(socket.SOL_IP,
+                                          SO_ORIGINAL_DST, SOCKADDR_MIN)
+            port, raw_ip = struct.unpack_from('!2xH4s', sockaddr_in[:8])
+            ip = str(ipaddress.IPv4Address(raw_ip))
+        elif family == socket.AF_INET6:
+            sockaddr_in = sock.getsockopt(41, SO_ORIGINAL_DST, 64)
+            port, raw_ip = struct.unpack_from("!2xH4x16s", sockaddr_in)
+            ip = str(ipaddress.IPv6Address(raw_ip))
+        else:
+            raise Fatal("fw: Unknown family type.")
+    except socket.error as e:
+        if e.args[0] == errno.ENOPROTOOPT:
+            return sock.getsockname()
+        raise
+    return (ip, port)
+
+
+class Features(object):
+    pass
+
+
+class BaseMethod(object):
+    def __init__(self, name):
+        self.firewall = None
+        self.name = name
+
+    def set_firewall(self, firewall):
+        self.firewall = firewall
+
+    @staticmethod
+    def get_supported_features():
+        result = Features()
+        result.loopback_proxy_port = True
+        result.ipv4 = True
+        result.ipv6 = False
+        result.udp = False
+        result.dns = True
+        result.user = False
+        result.group = False
+        return result
+
+    @staticmethod
+    def is_supported():
+        """Returns true if it appears that this method will work on this
+        machine."""
+        return False
+
+    @staticmethod
+    def get_tcp_dstip(sock):
+        return original_dst(sock)
+
+    @staticmethod
+    def recv_udp(udp_listener, bufsize):
+        debug3('Accept UDP using recvfrom.')
+        data, srcip = udp_listener.recvfrom(bufsize)
+        return (srcip, None, data)
+
+    def send_udp(self, sock, srcip, dstip, data):
+        if srcip is not None:
+            raise Fatal("Method %s send_udp does not support setting srcip to %r"
+                        % (self.name, srcip))
+        sock.sendto(data, dstip)
+
+    def setup_tcp_listener(self, tcp_listener):
+        pass
+
+    def setup_udp_listener(self, udp_listener):
+        pass
+
+    def assert_features(self, features):
+        avail = self.get_supported_features()
+        for key in ["udp", "dns", "ipv6", "ipv4", "user"]:
+            if getattr(features, key) and not getattr(avail, key):
+                raise Fatal(
+                    "Feature %s not supported with method %s." %
+                    (key, self.name))
+
+    def setup_firewall(self, port, dnsport, nslist, family, subnets, udp,
+                       user, group, tmark):
+        raise NotImplementedError()
+
+    def restore_firewall(self, port, family, udp, user, group):
+        raise NotImplementedError()
+
+    def wait_for_firewall_ready(self, sshuttle_pid):
+        raise NotImplementedError()
+
+    @staticmethod
+    def firewall_command(line):
+        return False
+
+
+def get_method(method_name):
+    module = importlib.import_module("sshuttle.methods.%s" % method_name)
+    return module.Method(method_name)
+
+
+def get_auto_method():
+    debug3("Selecting a method automatically...")
+    # Try these methods, in order:
+    methods_to_try = ["nat", "nft", "pf", "ipfw"] if sys.platform != "win32" else ["windivert"]
+    for m in methods_to_try:
+        method = get_method(m)
+        if method.is_supported():
+            debug3("Method '%s' was automatically selected." % m)
+            return method
+
+    raise Fatal("Unable to automatically find a supported method. Check that "
+                "the appropriate programs are in your PATH. We tried "
+                "methods: %s" % str(methods_to_try))

sshuttle/methods/ipfw.py

@@ -0,0 +1,226 @@
+import os
+import subprocess as ssubprocess
+from sshuttle.methods import BaseMethod
+from sshuttle.helpers import log, debug1, debug2, debug3, \
+    Fatal, family_to_string, get_env, which
+
+import socket
+
+IP_BINDANY = 24
+IP_RECVDSTADDR = 7
+SOL_IPV6 = 41
+IPV6_RECVDSTADDR = 74
+
+
+def recv_udp(listener, bufsize):
+    debug3('Accept UDP python using recvmsg.')
+    data, ancdata, _, srcip = listener.recvmsg(4096,
+                                               socket.CMSG_SPACE(4))
+    dstip = None
+    for cmsg_level, cmsg_type, cmsg_data in ancdata:
+        if cmsg_level == socket.SOL_IP and cmsg_type == IP_RECVDSTADDR:
+            port = 53
+            ip = socket.inet_ntop(socket.AF_INET, cmsg_data[0:4])
+            dstip = (ip, port)
+            break
+    return (srcip, dstip, data)
+
+
+def ipfw_rule_exists(n):
+    argv = ['ipfw', 'list', '%d' % n]
+    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, env=get_env())
+
+    found = False
+    for line in p.stdout:
+        if line.startswith(b'%05d ' % n):
+            if 'check-state :sshuttle' not in line:
+                log('non-sshuttle ipfw rule: %r' % line.strip())
+                raise Fatal('non-sshuttle ipfw rule #%d already exists!' % n)
+            found = True
+            break
+    rv = p.wait()
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+    return found
+
+
+_oldctls = {}
+
+
+def _fill_oldctls(prefix):
+    argv = ['sysctl', prefix]
+    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, env=get_env())
+    for line in p.stdout:
+        line = line.decode()
+        assert line[-1] == '\n'
+        (k, v) = line[:-1].split(': ', 1)
+        _oldctls[k] = v.strip()
+    rv = p.wait()
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+    if not line:
+        raise Fatal('%r returned no data' % (argv,))
+
+
+def _sysctl_set(name, val):
+    argv = ['sysctl', '-w', '%s=%s' % (name, val)]
+    debug1('>> %s' % ' '.join(argv))
+    return ssubprocess.call(argv, stdout=open(os.devnull, 'w'), env=get_env())
+    # No env: No output. (Or error that won't be parsed.)
+
+
+_changedctls = []
+
+
+def sysctl_set(name, val, permanent=False):
+    PREFIX = 'net.inet.ip'
+    assert name.startswith(PREFIX + '.')
+    val = str(val)
+    if not _oldctls:
+        _fill_oldctls(PREFIX)
+    if not (name in _oldctls):
+        debug1('>> No such sysctl: %r' % name)
+        return False
+    oldval = _oldctls[name]
+    if val != oldval:
+        rv = _sysctl_set(name, val)
+        if rv == 0 and permanent:
+            debug1('>>   ...saving permanently in /etc/sysctl.conf')
+            f = open('/etc/sysctl.conf', 'a')
+            f.write('\n'
+                    '# Added by sshuttle\n'
+                    '%s=%s\n' % (name, val))
+            f.close()
+        else:
+            _changedctls.append(name)
+        return True
+
+
+def ipfw(*args):
+    argv = ['ipfw', '-q'] + list(args)
+    debug1('>> %s' % ' '.join(argv))
+    rv = ssubprocess.call(argv, env=get_env())
+    # No env: No output. (Or error that won't be parsed.)
+    if rv:
+        raise Fatal('%r returned %d' % (argv, rv))
+
+
+def ipfw_noexit(*args):
+    argv = ['ipfw', '-q'] + list(args)
+    debug1('>> %s' % ' '.join(argv))
+    ssubprocess.call(argv, env=get_env())
+    # No env: No output. (Or error that won't be parsed.)
+
+
+class Method(BaseMethod):
+
+    def get_supported_features(self):
+        result = super(Method, self).get_supported_features()
+        result.ipv6 = False
+        result.udp = False  # NOTE: Almost there, kernel patch needed
+        result.dns = True
+        return result
+
+    def get_tcp_dstip(self, sock):
+        return sock.getsockname()
+
+    def recv_udp(self, udp_listener, bufsize):
+        srcip, dstip, data = recv_udp(udp_listener, bufsize)
+        if not dstip:
+            debug1(
+                   "-- ignored UDP from %r: "
+                   "couldn't determine destination IP address" % (srcip,))
+            return None
+        return srcip, dstip, data
+
+    def send_udp(self, sock, srcip, dstip, data):
+        if not srcip:
+            debug1(
+               "-- ignored UDP to %r: "
+               "couldn't determine source IP address" % (dstip,))
+            return
+
+        # debug3('Sending SRC: %r DST: %r' % (srcip, dstip))
+        sender = socket.socket(sock.family, socket.SOCK_DGRAM)
+        sender.setsockopt(socket.SOL_IP, IP_BINDANY, 1)
+        sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+        sender.bind(srcip)
+        sender.sendto(data, dstip)
+        sender.close()
+
+    def setup_udp_listener(self, udp_listener):
+        if udp_listener.v4 is not None:
+            udp_listener.v4.setsockopt(socket.SOL_IP, IP_RECVDSTADDR, 1)
+        # if udp_listener.v6 is not None:
+        #     udp_listener.v6.setsockopt(SOL_IPV6, IPV6_RECVDSTADDR, 1)
+
+    def setup_firewall(self, port, dnsport, nslist, family, subnets, udp,
+                       user, group, tmark):
+        # IPv6 not supported
+        if family not in [socket.AF_INET]:
+            raise Exception(
+                'Address family "%s" unsupported by ipfw method_name'
+                % family_to_string(family))
+
+        # XXX: Any risk from this?
+        ipfw_noexit('delete', '1')
+
+        while _changedctls:
+            name = _changedctls.pop()
+            oldval = _oldctls[name]
+            _sysctl_set(name, oldval)
+
+        if subnets or dnsport:
+            sysctl_set('net.inet.ip.fw.enable', 1)
+
+        ipfw('add', '1', 'check-state', ':sshuttle')
+
+        ipfw('add', '1', 'skipto', '2',
+             'tcp',
+             'from', 'any', 'to', 'table(125)')
+        ipfw('add', '1', 'fwd', '127.0.0.1,%d' % port,
+             'tcp',
+             'from', 'any', 'to', 'table(126)',
+             'setup', 'keep-state', ':sshuttle')
+
+        ipfw_noexit('table', '124', 'flush')
+        dnscount = 0
+        for _, ip in [i for i in nslist if i[0] == family]:
+            ipfw('table', '124', 'add', '%s' % (ip))
+            dnscount += 1
+        if dnscount > 0:
+            ipfw('add', '1', 'fwd', '127.0.0.1,%d' % dnsport,
+                 'udp',
+                 'from', 'any', 'to', 'table(124)',
+                 'keep-state', ':sshuttle')
+        ipfw('add', '1', 'allow',
+             'udp',
+             'from', 'any', 'to', 'any')
+
+        if subnets:
+            # create new subnet entries
+            for _, swidth, sexclude, snet, fport, lport \
+                    in sorted(subnets, key=lambda s: s[1], reverse=True):
+                if sexclude:
+                    ipfw('table', '125', 'add', '%s/%s' % (snet, swidth))
+                else:
+                    ipfw('table', '126', 'add', '%s/%s' % (snet, swidth))
+
+    def restore_firewall(self, port, family, udp, user, group):
+        if family not in [socket.AF_INET]:
+            raise Exception(
+                'Address family "%s" unsupported by ipfw method'
+                % family_to_string(family))
+
+        ipfw_noexit('delete', '1')
+        ipfw_noexit('table', '124', 'flush')
+        ipfw_noexit('table', '125', 'flush')
+        ipfw_noexit('table', '126', 'flush')
+
+    def is_supported(self):
+        if which("ipfw"):
+            return True
+        debug2("ipfw method not supported because 'ipfw' command is "
+               "missing.")
+        return False

sshuttle/methods/nat.py

@@ -0,0 +1,133 @@
+import socket
+from sshuttle.firewall import subnet_weight
+from sshuttle.helpers import family_to_string, which, debug2
+from sshuttle.linux import ipt, ipt_chain_exists, nonfatal
+from sshuttle.methods import BaseMethod
+
+
+class Method(BaseMethod):
+
+    # We name the chain based on the transproxy port number so that it's
+    # possible to run multiple copies of sshuttle at the same time.  Of course,
+    # the multiple copies shouldn't have overlapping subnets, or only the most-
+    # recently-started one will win (because we use "-I OUTPUT 1" instead of
+    # "-A OUTPUT").
+    def setup_firewall(self, port, dnsport, nslist, family, subnets, udp,
+                       user, group, tmark):
+        if family != socket.AF_INET and family != socket.AF_INET6:
+            raise Exception(
+                'Address family "%s" unsupported by nat method_name'
+                % family_to_string(family))
+        if udp:
+            raise Exception("UDP not supported by nat method_name")
+        table = "nat"
+
+        def _ipt(*args):
+            return ipt(family, table, *args)
+
+        def _ipm(*args):
+            return ipt(family, "mangle", *args)
+
+        chain = 'sshuttle-%s' % port
+
+        # basic cleanup/setup of chains
+        self.restore_firewall(port, family, udp, user, group)
+
+        _ipt('-N', chain)
+        _ipt('-F', chain)
+        if user is not None or group is not None:
+            margs = ['-I', 'OUTPUT', '1', '-m', 'owner']
+            if user is not None:
+                margs += ['--uid-owner', str(user)]
+            if group is not None:
+                margs += ['--gid-owner', str(group)]
+            margs += ['-j', 'MARK', '--set-mark', str(port)]
+            nonfatal(_ipm, *margs)
+            args = '-m', 'mark', '--mark', str(port), '-j', chain
+        else:
+            args = '-j', chain
+
+        _ipt('-I', 'OUTPUT', '1', *args)
+        _ipt('-I', 'PREROUTING', '1', *args)
+
+        # Redirect DNS traffic as requested. This includes routing traffic
+        # to localhost DNS servers through sshuttle.
+        for _, ip in [i for i in nslist if i[0] == family]:
+            _ipt('-A', chain, '-j', 'REDIRECT',
+                 '--dest', '%s' % ip,
+                 '-p', 'udp',
+                 '--dport', '53',
+                 '--to-ports', str(dnsport))
+
+        # create new subnet entries.
+        for _, swidth, sexclude, snet, fport, lport \
+                in sorted(subnets, key=subnet_weight, reverse=True):
+            tcp_ports = ('-p', 'tcp')
+            if fport:
+                tcp_ports = tcp_ports + ('--dport', '%d:%d' % (fport, lport))
+
+            if sexclude:
+                _ipt('-A', chain, '-j', 'RETURN',
+                     '--dest', '%s/%s' % (snet, swidth),
+                     *tcp_ports)
+            else:
+                _ipt('-A', chain, '-j', 'REDIRECT',
+                     '--dest', '%s/%s' % (snet, swidth),
+                     *(tcp_ports + ('--to-ports', str(port))))
+
+        # Don't route any remaining local traffic through sshuttle.
+        _ipt('-A', chain, '-j', 'RETURN',
+             '-m', 'addrtype',
+             '--dst-type', 'LOCAL')
+
+    def restore_firewall(self, port, family, udp, user, group):
+        # only ipv4 supported with NAT
+        if family != socket.AF_INET and family != socket.AF_INET6:
+            raise Exception(
+                'Address family "%s" unsupported by nat method_name'
+                % family_to_string(family))
+        if udp:
+            raise Exception("UDP not supported by nat method_name")
+
+        table = "nat"
+
+        def _ipt(*args):
+            return ipt(family, table, *args)
+
+        def _ipm(*args):
+            return ipt(family, "mangle", *args)
+
+        chain = 'sshuttle-%s' % port
+
+        # basic cleanup/setup of chains
+        if ipt_chain_exists(family, table, chain):
+            if user is not None or group is not None:
+                margs = ['-D', 'OUTPUT', '-m', 'owner']
+                if user is not None:
+                    margs += ['--uid-owner', str(user)]
+                if group is not None:
+                    margs += ['--gid-owner', str(group)]
+                margs += ['-j', 'MARK', '--set-mark', str(port)]
+                nonfatal(_ipm, *margs)
+
+                args = '-m', 'mark', '--mark', str(port), '-j', chain
+            else:
+                args = '-j', chain
+            nonfatal(_ipt, '-D', 'OUTPUT', *args)
+            nonfatal(_ipt, '-D', 'PREROUTING', *args)
+            nonfatal(_ipt, '-F', chain)
+            _ipt('-X', chain)
+
+    def get_supported_features(self):
+        result = super(Method, self).get_supported_features()
+        result.user = True
+        result.ipv6 = True
+        result.group = True
+        return result
+
+    def is_supported(self):
+        if which("iptables"):
+            return True
+        debug2("nat method not supported because 'iptables' command "
+               "is missing.")
+        return False

sshuttle/methods/nft.py

@@ -0,0 +1,114 @@
+import socket
+from sshuttle.firewall import subnet_weight
+from sshuttle.linux import nft, nonfatal
+from sshuttle.methods import BaseMethod
+from sshuttle.helpers import debug2, which
+
+
+class Method(BaseMethod):
+
+    # We name the chain based on the transproxy port number so that it's
+    # possible to run multiple copies of sshuttle at the same time.  Of course,
+    # the multiple copies shouldn't have overlapping subnets, or only the most-
+    # recently-started one will win (because we use "-I OUTPUT 1" instead of
+    # "-A OUTPUT").
+    def setup_firewall(self, port, dnsport, nslist, family, subnets, udp,
+                       user, group, tmark):
+        if udp:
+            raise Exception("UDP not supported by nft")
+
+        if family == socket.AF_INET:
+            table = 'sshuttle-ipv4-%s' % port
+        if family == socket.AF_INET6:
+            table = 'sshuttle-ipv6-%s' % port
+
+        def _nft(action, *args):
+            return nft(family, table, action, *args)
+
+        chain = table
+
+        # basic cleanup/setup of chains
+        _nft('add table', '')
+        _nft('add chain', 'prerouting',
+             '{ type nat hook prerouting priority -100; policy accept; }')
+        _nft('add chain', 'output',
+             '{ type nat hook output priority -100; policy accept; }')
+        _nft('add chain', chain)
+        _nft('flush chain', chain)
+        _nft('add rule', 'output jump %s' % chain)
+        _nft('add rule', 'prerouting jump %s' % chain)
+
+        # setup_firewall() gets called separately for ipv4 and ipv6. Make sure
+        # we only handle the version that we expect to.
+        if family == socket.AF_INET:
+            _nft('add rule', chain, 'meta', 'nfproto', '!=', 'ipv4', 'return')
+        else:
+            _nft('add rule', chain, 'meta', 'nfproto', '!=', 'ipv6', 'return')
+
+        # Strings to use below to simplify our code
+        if family == socket.AF_INET:
+            ip_version_l = 'ipv4'
+            ip_version = 'ip'
+        elif family == socket.AF_INET6:
+            ip_version_l = 'ipv6'
+            ip_version = 'ip6'
+
+        # Redirect DNS traffic as requested. This includes routing traffic
+        # to localhost DNS servers through sshuttle.
+        for _, ip in [i for i in nslist if i[0] == family]:
+            _nft('add rule', chain, ip_version,
+                 'daddr %s' % ip, 'udp dport 53',
+                 ('redirect to :' + str(dnsport)))
+
+        # Don't route any remaining local traffic through sshuttle
+        _nft('add rule', chain, 'fib daddr type local return')
+
+        # create new subnet entries.
+        for _, swidth, sexclude, snet, fport, lport \
+                in sorted(subnets, key=subnet_weight, reverse=True):
+
+            # match using nfproto as described at
+            # https://superuser.com/questions/1560376/match-ipv6-protocol-using-nftables
+            if fport and fport != lport:
+                tcp_ports = ('meta', 'nfproto', ip_version_l, 'tcp',
+                             'dport', '{ %d-%d }' % (fport, lport))
+            elif fport and fport == lport:
+                tcp_ports = ('meta', 'nfproto', ip_version_l, 'tcp',
+                             'dport', '%d' % (fport))
+            else:
+                tcp_ports = ('meta', 'nfproto', ip_version_l,
+                             'meta', 'l4proto', 'tcp')
+
+            if sexclude:
+                _nft('add rule', chain, *(tcp_ports + (
+                     ip_version, 'daddr %s/%s' % (snet, swidth), 'return')))
+            else:
+                _nft('add rule', chain, *(tcp_ports + (
+                    ip_version, 'daddr %s/%s' % (snet, swidth),
+                    ('redirect to :' + str(port)))))
+
+    def restore_firewall(self, port, family, udp, user, group):
+        if udp:
+            raise Exception("UDP not supported by nft method_name")
+
+        if family == socket.AF_INET:
+            table = 'sshuttle-ipv4-%s' % port
+        if family == socket.AF_INET6:
+            table = 'sshuttle-ipv6-%s' % port
+
+        def _nft(action, *args):
+            return nft(family, table, action, *args)
+
+        # basic cleanup/setup of chains
+        nonfatal(_nft, 'delete table', '')
+
+    def get_supported_features(self):
+        result = super(Method, self).get_supported_features()
+        result.ipv6 = True
+        return result
+
+    def is_supported(self):
+        if which("nft"):
+            return True
+        debug2("nft method not supported because 'nft' command is missing.")
+        return False

sshuttle/methods/pf.py

@@ -0,0 +1,503 @@
+import os
+import sys
+import platform
+import re
+import socket
+import errno
+import struct
+import subprocess as ssubprocess
+import shlex
+from fcntl import ioctl
+from ctypes import c_char, c_uint8, c_uint16, c_uint32, Union, Structure, \
+    sizeof, addressof, memmove
+from sshuttle.firewall import subnet_weight
+from sshuttle.helpers import log, debug1, debug2, debug3, Fatal, \
+     family_to_string, get_env, which
+from sshuttle.methods import BaseMethod
+
+
+_pf_context = {
+    'started_by_sshuttle': 0,
+    'loaded_by_sshuttle': True,
+    'Xtoken': []
+}
+_pf_fd = None
+
+
+class Generic(object):
+    MAXPATHLEN = 1024
+    PF_CHANGE_ADD_TAIL = 2
+    PF_CHANGE_GET_TICKET = 6
+    PF_PASS = 0
+    PF_RDR = 8
+    PF_OUT = 2
+    ACTION_OFFSET = 0
+    POOL_TICKET_OFFSET = 8
+    ANCHOR_CALL_OFFSET = 1040
+
+    class pf_addr(Structure):
+        class _pfa(Union):
+            _fields_ = [("v4", c_uint32),      # struct in_addr
+                        ("v6", c_uint32 * 4),  # struct in6_addr
+                        ("addr8", c_uint8 * 16),
+                        ("addr16", c_uint16 * 8),
+                        ("addr32", c_uint32 * 4)]
+
+        _fields_ = [("pfa", _pfa)]
+        _anonymous_ = ("pfa",)
+
+    def __init__(self):
+        self.status = b''
+        self.pfioc_pooladdr = c_char * 1136
+
+        self.DIOCNATLOOK = (
+            (0x40000000 | 0x80000000) |
+            ((sizeof(self.pfioc_natlook) & 0x1fff) << 16) |
+            ((ord('D')) << 8) | (23))
+        self.DIOCCHANGERULE = (
+            (0x40000000 | 0x80000000) |
+            ((sizeof(self.pfioc_rule) & 0x1fff) << 16) |
+            ((ord('D')) << 8) | (26))
+        self.DIOCBEGINADDRS = (
+            (0x40000000 | 0x80000000) |
+            ((sizeof(self.pfioc_pooladdr) & 0x1fff) << 16) |
+            ((ord('D')) << 8) | (51))
+
+    def enable(self):
+        if b'INFO:\nStatus: Disabled' in self.status:
+            pfctl('-e')
+            _pf_context['started_by_sshuttle'] += 1
+
+    @staticmethod
+    def disable(anchor):
+        pfctl('-a %s -F all' % anchor)
+        if _pf_context['started_by_sshuttle'] == 1:
+            pfctl('-d')
+        _pf_context['started_by_sshuttle'] -= 1
+
+    def query_nat(self, family, proto, src_ip, src_port, dst_ip, dst_port):
+        [proto, family, src_port, dst_port] = [
+            int(v) for v in [proto, family, src_port, dst_port]]
+
+        packed_src_ip = socket.inet_pton(family, src_ip)
+        packed_dst_ip = socket.inet_pton(family, dst_ip)
+
+        assert len(packed_src_ip) == len(packed_dst_ip)
+        length = len(packed_src_ip)
+
+        pnl = self.pfioc_natlook()
+        pnl.proto = proto
+        pnl.direction = self.PF_OUT
+        pnl.af = family
+        memmove(addressof(pnl.saddr), packed_src_ip, length)
+        memmove(addressof(pnl.daddr), packed_dst_ip, length)
+        self._add_natlook_ports(pnl, src_port, dst_port)
+
+        ioctl(pf_get_dev(), self.DIOCNATLOOK,
+              (c_char * sizeof(pnl)).from_address(addressof(pnl)))
+
+        ip = socket.inet_ntop(
+            pnl.af, (c_char * length).from_address(addressof(pnl.rdaddr)).raw)
+        port = socket.ntohs(self._get_natlook_port(pnl.rdxport))
+        return (ip, port)
+
+    @staticmethod
+    def _add_natlook_ports(pnl, src_port, dst_port):
+        pnl.sxport = socket.htons(src_port)
+        pnl.dxport = socket.htons(dst_port)
+
+    @staticmethod
+    def _get_natlook_port(xport):
+        return xport
+
+    def add_anchors(self, anchor, status=None):
+        if status is None:
+            status = pfctl('-s all')[0]
+        self.status = status
+        if ('\nanchor "%s"' % anchor).encode('ASCII') not in status:
+            self._add_anchor_rule(self.PF_PASS, anchor.encode('ASCII'))
+
+    def _add_anchor_rule(self, kind, name, pr=None):
+        if pr is None:
+            pr = self.pfioc_rule()
+
+        memmove(addressof(pr) + self.ANCHOR_CALL_OFFSET, name,
+                min(self.MAXPATHLEN, len(name)))  # anchor_call = name
+        memmove(addressof(pr) + self.RULE_ACTION_OFFSET,
+                struct.pack('I', kind), 4)  # rule.action = kind
+
+        memmove(addressof(pr) + self.ACTION_OFFSET,
+                struct.pack('I', self.PF_CHANGE_GET_TICKET),
+                4)  # action = PF_CHANGE_GET_TICKET
+        ioctl(pf_get_dev(), pf.DIOCCHANGERULE, pr)
+
+        memmove(addressof(pr) + self.ACTION_OFFSET,
+                struct.pack('I', self.PF_CHANGE_ADD_TAIL),
+                4)  # action = PF_CHANGE_ADD_TAIL
+        ioctl(pf_get_dev(), pf.DIOCCHANGERULE, pr)
+
+    @staticmethod
+    def _inet_version(family):
+        return b'inet' if family == socket.AF_INET else b'inet6'
+
+    @staticmethod
+    def _lo_addr(family):
+        return b'127.0.0.1' if family == socket.AF_INET else b'::1'
+
+    @staticmethod
+    def add_rules(anchor, rules):
+        assert isinstance(rules, bytes)
+        debug3("rules:\n" + rules.decode("ASCII"))
+        pfctl('-a %s -f /dev/stdin' % anchor, rules)
+
+    @staticmethod
+    def has_skip_loopback():
+        return b'skip' in pfctl('-s Interfaces -i lo -v')[0]
+
+
+class FreeBsd(Generic):
+    RULE_ACTION_OFFSET = 2968
+
+    def __new__(cls):
+        class pfioc_natlook(Structure):
+            pf_addr = Generic.pf_addr
+            _fields_ = [("saddr", pf_addr),
+                        ("daddr", pf_addr),
+                        ("rsaddr", pf_addr),
+                        ("rdaddr", pf_addr),
+                        ("sxport", c_uint16),
+                        ("dxport", c_uint16),
+                        ("rsxport", c_uint16),
+                        ("rdxport", c_uint16),
+                        ("af", c_uint8),                      # sa_family_t
+                        ("proto", c_uint8),
+                        ("proto_variant", c_uint8),
+                        ("direction", c_uint8)]
+
+        freebsd = Generic.__new__(cls)
+        freebsd.pfioc_rule = c_char * 3040
+        freebsd.pfioc_natlook = pfioc_natlook
+        return freebsd
+
+    def enable(self):
+        returncode = ssubprocess.call(['kldload', 'pf'], env=get_env())
+        # No env: No output.
+        super(FreeBsd, self).enable()
+        if returncode == 0:
+            _pf_context['loaded_by_sshuttle'] = True
+
+    def disable(self, anchor):
+        super(FreeBsd, self).disable(anchor)
+        if _pf_context['loaded_by_sshuttle'] and \
+                _pf_context['started_by_sshuttle'] == 0:
+            ssubprocess.call(['kldunload', 'pf'], env=get_env())
+            # No env: No output.
+
+    def add_anchors(self, anchor):
+        status = pfctl('-s all')[0]
+        if ('\nrdr-anchor "%s"' % anchor).encode('ASCII') not in status:
+            self._add_anchor_rule(self.PF_RDR, anchor.encode('ASCII'))
+        super(FreeBsd, self).add_anchors(anchor, status=status)
+
+    def _add_anchor_rule(self, kind, name, pr=None):
+        pr = pr or self.pfioc_rule()
+        ppa = self.pfioc_pooladdr()
+
+        ioctl(pf_get_dev(), self.DIOCBEGINADDRS, ppa)
+        # pool ticket
+        memmove(addressof(pr) + self.POOL_TICKET_OFFSET, ppa[4:8], 4)
+        super(FreeBsd, self)._add_anchor_rule(kind, name, pr=pr)
+
+    def add_rules(self, anchor, includes, port, dnsport, nslist, family):
+        inet_version = self._inet_version(family)
+        lo_addr = self._lo_addr(family)
+
+        tables = []
+        translating_rules = [
+            b'rdr pass on lo0 %s proto tcp from ! %s to %s '
+            b'-> %s port %r' % (inet_version, lo_addr, subnet, lo_addr, port)
+            for exclude, subnet in includes if not exclude
+        ]
+        filtering_rules = [
+            b'pass out route-to lo0 %s proto tcp '
+            b'to %s keep state' % (inet_version, subnet)
+            if not exclude else
+            b'pass out %s proto tcp to %s' % (inet_version, subnet)
+            for exclude, subnet in includes
+        ]
+
+        if nslist:
+            tables.append(
+                b'table <dns_servers> {%s}' %
+                b','.join([ns[1].encode("ASCII") for ns in nslist]))
+            translating_rules.append(
+                b'rdr pass on lo0 %s proto udp to <dns_servers> '
+                b'port 53 -> %s port %r' % (inet_version, lo_addr, dnsport))
+            filtering_rules.append(
+                b'pass out route-to lo0 %s proto udp to '
+                b'<dns_servers> port 53 keep state' % inet_version)
+
+        rules = b'\n'.join(tables + translating_rules + filtering_rules) \
+                + b'\n'
+
+        super(FreeBsd, self).add_rules(anchor, rules)
+
+
+class OpenBsd(Generic):
+    POOL_TICKET_OFFSET = 4
+    RULE_ACTION_OFFSET = 3324
+    ANCHOR_CALL_OFFSET = 1036
+
+    def __init__(self):
+        class pfioc_natlook(Structure):
+            pf_addr = Generic.pf_addr
+            _fields_ = [("saddr", pf_addr),
+                        ("daddr", pf_addr),
+                        ("rsaddr", pf_addr),
+                        ("rdaddr", pf_addr),
+                        ("rdomain", c_uint16),
+                        ("rrdomain", c_uint16),
+                        ("sxport", c_uint16),
+                        ("dxport", c_uint16),
+                        ("rsxport", c_uint16),
+                        ("rdxport", c_uint16),
+                        ("af", c_uint8),                      # sa_family_t
+                        ("proto", c_uint8),
+                        ("proto_variant", c_uint8),
+                        ("direction", c_uint8)]
+
+        self.pfioc_rule = c_char * 3408
+        self.pfioc_natlook = pfioc_natlook
+        super(OpenBsd, self).__init__()
+
+    def add_anchors(self, anchor):
+        # before adding anchors and rules we must override the skip lo
+        # that comes by default in openbsd pf.conf so the rules we will add,
+        # which rely on translating/filtering packets on lo, can work
+        if self.has_skip_loopback():
+            pfctl('-f /dev/stdin', b'match on lo\n')
+        super(OpenBsd, self).add_anchors(anchor)
+
+    def add_rules(self, anchor, includes, port, dnsport, nslist, family):
+        inet_version = self._inet_version(family)
+        lo_addr = self._lo_addr(family)
+
+        tables = []
+        translating_rules = [
+            b'pass in on lo0 %s proto tcp to %s '
+            b'divert-to %s port %r' % (inet_version, subnet, lo_addr, port)
+            for exclude, subnet in includes if not exclude
+        ]
+        filtering_rules = [
+            b'pass out %s proto tcp to %s '
+            b'route-to lo0 keep state' % (inet_version, subnet)
+            if not exclude else
+            b'pass out %s proto tcp to %s' % (inet_version, subnet)
+            for exclude, subnet in includes
+        ]
+
+        if nslist:
+            tables.append(
+                b'table <dns_servers> {%s}' %
+                b','.join([ns[1].encode("ASCII") for ns in nslist]))
+            translating_rules.append(
+                b'pass in on lo0 %s proto udp to <dns_servers> port 53 '
+                b'rdr-to %s port %r' % (inet_version, lo_addr, dnsport))
+            filtering_rules.append(
+                b'pass out %s proto udp to <dns_servers> port 53 '
+                b'route-to lo0 keep state' % inet_version)
+
+        rules = b'\n'.join(tables + translating_rules + filtering_rules) \
+                + b'\n'
+
+        super(OpenBsd, self).add_rules(anchor, rules)
+
+
+class Darwin(FreeBsd):
+    RULE_ACTION_OFFSET = 3068
+
+    def __init__(self):
+        class pf_state_xport(Union):
+            _fields_ = [("port", c_uint16),
+                        ("call_id", c_uint16),
+                        ("spi", c_uint32)]
+
+        class pfioc_natlook(Structure):
+            pf_addr = Generic.pf_addr
+            _fields_ = [("saddr", pf_addr),
+                        ("daddr", pf_addr),
+                        ("rsaddr", pf_addr),
+                        ("rdaddr", pf_addr),
+                        ("sxport", pf_state_xport),
+                        ("dxport", pf_state_xport),
+                        ("rsxport", pf_state_xport),
+                        ("rdxport", pf_state_xport),
+                        ("af", c_uint8),                      # sa_family_t
+                        ("proto", c_uint8),
+                        ("proto_variant", c_uint8),
+                        ("direction", c_uint8)]
+
+        self.pfioc_rule = c_char * 3104
+        self.pfioc_natlook = pfioc_natlook
+        super(Darwin, self).__init__()
+
+    def enable(self):
+        o = pfctl('-E')
+        _pf_context['Xtoken'].append(re.search(b'Token : (.+)', o[1]).group(1))
+
+    def disable(self, anchor):
+        pfctl('-a %s -F all' % anchor)
+        if _pf_context['Xtoken']:
+            pfctl('-X %s' % _pf_context['Xtoken'].pop().decode("ASCII"))
+
+    def add_anchors(self, anchor):
+        # before adding anchors and rules we must override the skip lo
+        # that in some cases ends up in the chain so the rules we will add,
+        # which rely on translating/filtering packets on lo, can work
+        if self.has_skip_loopback():
+            pfctl('-f /dev/stdin', b'pass on lo\n')
+        super(Darwin, self).add_anchors(anchor)
+
+    def _add_natlook_ports(self, pnl, src_port, dst_port):
+        pnl.sxport.port = socket.htons(src_port)
+        pnl.dxport.port = socket.htons(dst_port)
+
+    def _get_natlook_port(self, xport):
+        return xport.port
+
+
+class PfSense(FreeBsd):
+    RULE_ACTION_OFFSET = 3040
+
+    def __init__(self):
+        self.pfioc_rule = c_char * 3112
+        super(PfSense, self).__init__()
+
+
+if sys.platform == 'darwin':
+    pf = Darwin()
+elif sys.platform.startswith('openbsd'):
+    pf = OpenBsd()
+elif platform.version().endswith('pfSense'):
+    pf = PfSense()
+else:
+    pf = FreeBsd()
+
+
+def pfctl(args, stdin=None):
+    argv = ['pfctl'] + shlex.split(args)
+    debug1('>> %s' % ' '.join(argv))
+    p = ssubprocess.Popen(argv, stdin=ssubprocess.PIPE,
+                          stdout=ssubprocess.PIPE,
+                          stderr=ssubprocess.PIPE,
+                          env=get_env())
+    o = p.communicate(stdin)
+    if p.returncode:
+        log('%r returned %d, stdout and stderr follows: ' %
+            (argv, p.returncode))
+        log("stdout:\n%s" % o[0].decode("ascii"))
+        log("stderr:\n%s" % o[1].decode("ascii"))
+        raise Fatal('%r returned %d' % (argv, p.returncode))
+
+    return o
+
+
+def pf_get_dev():
+    global _pf_fd
+    if _pf_fd is None:
+        _pf_fd = os.open('/dev/pf', os.O_RDWR)
+
+    return _pf_fd
+
+
+def pf_get_anchor(family, port):
+    return 'sshuttle%s-%d' % ('' if family == socket.AF_INET else '6', port)
+
+
+class Method(BaseMethod):
+
+    def get_supported_features(self):
+        result = super(Method, self).get_supported_features()
+        result.ipv6 = True
+        return result
+
+    def get_tcp_dstip(self, sock):
+        pfile = self.firewall.pfile
+
+        try:
+            peer = sock.getpeername()
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            if e.args[0] == errno.EINVAL:
+                return sock.getsockname()
+
+        proxy = sock.getsockname()
+
+        argv = (sock.family, socket.IPPROTO_TCP,
+                peer[0].encode("ASCII"), peer[1],
+                proxy[0].encode("ASCII"), proxy[1])
+        out_line = b"QUERY_PF_NAT %d,%d,%s,%d,%s,%d\n" % argv
+        pfile.write(out_line)
+        pfile.flush()
+        in_line = pfile.readline()
+        debug2(out_line.decode("ASCII") + ' > ' + in_line.decode("ASCII"))
+        if in_line.startswith(b'QUERY_PF_NAT_SUCCESS '):
+            (ip, port) = in_line[21:].split(b',')
+            return (ip.decode("ASCII"), int(port))
+
+        return sock.getsockname()
+
+    def setup_firewall(self, port, dnsport, nslist, family, subnets, udp,
+                       user, group, tmark):
+        if family not in [socket.AF_INET, socket.AF_INET6]:
+            raise Exception(
+                'Address family "%s" unsupported by pf method_name'
+                % family_to_string(family))
+        if udp:
+            raise Exception("UDP not supported by pf method_name")
+
+        if subnets:
+            includes = []
+            # If a given subnet is both included and excluded, list the
+            # exclusion first; the table will ignore the second, opposite
+            # definition
+            for _, swidth, sexclude, snet, fport, lport \
+                    in sorted(subnets, key=subnet_weight):
+                includes.append((sexclude, b"%s/%d%s" % (
+                    snet.encode("ASCII"),
+                    swidth,
+                    b" port %d:%d" % (fport, lport) if fport else b"")))
+
+        anchor = pf_get_anchor(family, port)
+        pf.add_anchors(anchor)
+        pf.add_rules(anchor, includes, port, dnsport, nslist, family)
+        pf.enable()
+
+    def restore_firewall(self, port, family, udp, user, group):
+        if family not in [socket.AF_INET, socket.AF_INET6]:
+            raise Exception(
+                'Address family "%s" unsupported by pf method_name'
+                % family_to_string(family))
+        if udp:
+            raise Exception("UDP not supported by pf method_name")
+
+        pf.disable(pf_get_anchor(family, port))
+
+    def firewall_command(self, line):
+        if line.startswith('QUERY_PF_NAT '):
+            try:
+                dst = pf.query_nat(*(line[13:].split(',')))
+                sys.stdout.write('QUERY_PF_NAT_SUCCESS %s,%r\n' % dst)
+            except IOError as e:
+                sys.stdout.write('QUERY_PF_NAT_FAILURE %s\n' % e)
+
+            sys.stdout.flush()
+            return True
+        else:
+            return False
+
+    def is_supported(self):
+        if which("pfctl"):
+            return True
+        debug2("pf method not supported because 'pfctl' command is missing.")
+        return False

sshuttle/methods/tproxy.py

@@ -0,0 +1,266 @@
+import struct
+from sshuttle.firewall import subnet_weight
+from sshuttle.helpers import family_to_string
+from sshuttle.linux import ipt, ipt_chain_exists
+from sshuttle.methods import BaseMethod
+from sshuttle.helpers import debug1, debug2, debug3, Fatal, which
+
+import socket
+import os
+
+
+IP_TRANSPARENT = 19
+IP_ORIGDSTADDR = 20
+IP_RECVORIGDSTADDR = IP_ORIGDSTADDR
+SOL_IPV6 = 41
+IPV6_ORIGDSTADDR = 74
+IPV6_RECVORIGDSTADDR = IPV6_ORIGDSTADDR
+
+
+def recv_udp(listener, bufsize):
+    debug3('Accept UDP python using recvmsg.')
+    data, ancdata, _, srcip = listener.recvmsg(
+        4096, socket.CMSG_SPACE(24))
+    dstip = None
+    family = None
+    for cmsg_level, cmsg_type, cmsg_data in ancdata:
+        if cmsg_level == socket.SOL_IP and cmsg_type == IP_ORIGDSTADDR:
+            family, port = struct.unpack('=HH', cmsg_data[0:4])
+            port = socket.htons(port)
+            if family == socket.AF_INET:
+                start = 4
+                length = 4
+            else:
+                raise Fatal("Unsupported socket type '%s'" % family)
+            ip = socket.inet_ntop(family, cmsg_data[start:start + length])
+            dstip = (ip, port)
+            break
+        elif cmsg_level == SOL_IPV6 and cmsg_type == IPV6_ORIGDSTADDR:
+            family, port = struct.unpack('=HH', cmsg_data[0:4])
+            port = socket.htons(port)
+            if family == socket.AF_INET6:
+                start = 8
+                length = 16
+            else:
+                raise Fatal("Unsupported socket type '%s'" % family)
+            ip = socket.inet_ntop(family, cmsg_data[start:start + length])
+            dstip = (ip, port)
+            break
+    return (srcip, dstip, data)
+
+
+class Method(BaseMethod):
+
+    def get_supported_features(self):
+        result = super(Method, self).get_supported_features()
+        result.ipv6 = True
+        result.udp = True
+        result.dns = True
+        return result
+
+    def get_tcp_dstip(self, sock):
+        return sock.getsockname()
+
+    def recv_udp(self, udp_listener, bufsize):
+        srcip, dstip, data = recv_udp(udp_listener, bufsize)
+        if not dstip:
+            debug1(
+                "-- ignored UDP from %r: "
+                "couldn't determine destination IP address\n" % (srcip,))
+            return None
+        return srcip, dstip, data
+
+    def setsockopt_error(self, e):
+        """The tproxy method needs root permissions to successfully
+        set the IP_TRANSPARENT option on sockets. This method is
+        called when we receive a PermissionError when trying to do
+        so."""
+        raise Fatal("Insufficient permissions for tproxy method.\n"
+                    "Your effective UID is %d, not 0. Try rerunning as root.\n"
+                    % os.geteuid())
+
+    def send_udp(self, sock, srcip, dstip, data):
+        if not srcip:
+            debug1(
+                "-- ignored UDP to %r: "
+                "couldn't determine source IP address\n" % (dstip,))
+            return
+        sender = socket.socket(sock.family, socket.SOCK_DGRAM)
+        sender.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        try:
+            sender.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+        except PermissionError as e:
+            self.setsockopt_error(e)
+        sender.bind(srcip)
+        sender.sendto(data, dstip)
+        sender.close()
+
+    def setup_tcp_listener(self, tcp_listener):
+        try:
+            tcp_listener.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+        except PermissionError as e:
+            self.setsockopt_error(e)
+
+    def setup_udp_listener(self, udp_listener):
+        try:
+            udp_listener.setsockopt(socket.SOL_IP, IP_TRANSPARENT, 1)
+        except PermissionError as e:
+            self.setsockopt_error(e)
+
+        if udp_listener.v4 is not None:
+            udp_listener.v4.setsockopt(
+                socket.SOL_IP, IP_RECVORIGDSTADDR, 1)
+        if udp_listener.v6 is not None:
+            udp_listener.v6.setsockopt(SOL_IPV6, IPV6_RECVORIGDSTADDR, 1)
+
+    def setup_firewall(self, port, dnsport, nslist, family, subnets, udp,
+                       user, group, tmark):
+        if family not in [socket.AF_INET, socket.AF_INET6]:
+            raise Exception(
+                'Address family "%s" unsupported by tproxy method'
+                % family_to_string(family))
+
+        table = "mangle"
+
+        def _ipt(*args):
+            return ipt(family, table, *args)
+
+        def _ipt_proto_ports(proto, fport, lport):
+            return proto + ('--dport', '%d:%d' % (fport, lport)) \
+                if fport else proto
+
+        mark_chain = 'sshuttle-m-%s' % port
+        tproxy_chain = 'sshuttle-t-%s' % port
+        divert_chain = 'sshuttle-d-%s' % port
+
+        # basic cleanup/setup of chains
+        self.restore_firewall(port, family, udp, user, group)
+
+        _ipt('-N', mark_chain)
+        _ipt('-F', mark_chain)
+        _ipt('-N', divert_chain)
+        _ipt('-F', divert_chain)
+        _ipt('-N', tproxy_chain)
+        _ipt('-F', tproxy_chain)
+        _ipt('-I', 'OUTPUT', '1', '-j', mark_chain)
+        _ipt('-I', 'PREROUTING', '1', '-j', tproxy_chain)
+
+        for _, ip in [i for i in nslist if i[0] == family]:
+            _ipt('-A', mark_chain, '-j', 'MARK', '--set-mark', tmark,
+                 '--dest', '%s/32' % ip,
+                 '-m', 'udp', '-p', 'udp', '--dport', '53')
+            _ipt('-A', tproxy_chain, '-j', 'TPROXY',
+                 '--tproxy-mark', tmark,
+                 '--dest', '%s/32' % ip,
+                 '-m', 'udp', '-p', 'udp', '--dport', '53',
+                 '--on-port', str(dnsport))
+
+        # Don't have packets sent to any of our local IP addresses go
+        # through the tproxy or mark chains (except DNS ones).
+        #
+        # Without this fix, if a large subnet is redirected through
+        # sshuttle (i.e., 0/0), then the user may be unable to receive
+        # UDP responses or connect to their own machine using an IP
+        # besides (127.0.0.1). Prior to including these lines, the
+        # documentation reminded the user to use -x to exclude their
+        # own IP addresses to receive UDP responses if they are
+        # redirecting a large subnet through sshuttle (i.e., 0/0).
+        _ipt('-A', tproxy_chain, '-j', 'RETURN', '-m', 'addrtype',
+             '--dst-type', 'LOCAL')
+        _ipt('-A', mark_chain, '-j', 'RETURN', '-m', 'addrtype',
+             '--dst-type', 'LOCAL')
+
+        _ipt('-A', divert_chain, '-j', 'MARK', '--set-mark', tmark)
+        _ipt('-A', divert_chain, '-j', 'ACCEPT')
+        _ipt('-A', tproxy_chain, '-m', 'socket', '-j', divert_chain,
+             '-m', 'tcp', '-p', 'tcp')
+
+        if udp:
+            _ipt('-A', tproxy_chain, '-m', 'socket', '-j', divert_chain,
+                 '-m', 'udp', '-p', 'udp')
+
+        for _, swidth, sexclude, snet, fport, lport \
+                in sorted(subnets, key=subnet_weight, reverse=True):
+            tcp_ports = ('-p', 'tcp')
+            tcp_ports = _ipt_proto_ports(tcp_ports, fport, lport)
+
+            if sexclude:
+                _ipt('-A', mark_chain, '-j', 'RETURN',
+                     '--dest', '%s/%s' % (snet, swidth),
+                     '-m', 'tcp',
+                     *tcp_ports)
+                _ipt('-A', tproxy_chain, '-j', 'RETURN',
+                     '--dest', '%s/%s' % (snet, swidth),
+                     '-m', 'tcp',
+                     *tcp_ports)
+            else:
+                _ipt('-A', mark_chain, '-j', 'MARK', '--set-mark', tmark,
+                     '--dest', '%s/%s' % (snet, swidth),
+                     '-m', 'tcp',
+                     *tcp_ports)
+                _ipt('-A', tproxy_chain, '-j', 'TPROXY',
+                     '--tproxy-mark', tmark,
+                     '--dest', '%s/%s' % (snet, swidth),
+                     '-m', 'tcp',
+                     *(tcp_ports + ('--on-port', str(port))))
+
+            if udp:
+                udp_ports = ('-p', 'udp')
+                udp_ports = _ipt_proto_ports(udp_ports, fport, lport)
+
+                if sexclude:
+                    _ipt('-A', mark_chain, '-j', 'RETURN',
+                         '--dest', '%s/%s' % (snet, swidth),
+                         '-m', 'udp',
+                         *udp_ports)
+                    _ipt('-A', tproxy_chain, '-j', 'RETURN',
+                         '--dest', '%s/%s' % (snet, swidth),
+                         '-m', 'udp',
+                         *udp_ports)
+                else:
+                    _ipt('-A', mark_chain, '-j', 'MARK', '--set-mark', tmark,
+                         '--dest', '%s/%s' % (snet, swidth),
+                         '-m', 'udp',
+                         *udp_ports)
+                    _ipt('-A', tproxy_chain, '-j', 'TPROXY',
+                         '--tproxy-mark', tmark,
+                         '--dest', '%s/%s' % (snet, swidth),
+                         '-m', 'udp',
+                         *(udp_ports + ('--on-port', str(port))))
+
+    def restore_firewall(self, port, family, udp, user, group):
+        if family not in [socket.AF_INET, socket.AF_INET6]:
+            raise Exception(
+                'Address family "%s" unsupported by tproxy method'
+                % family_to_string(family))
+
+        table = "mangle"
+
+        def _ipt(*args):
+            return ipt(family, table, *args)
+
+        mark_chain = 'sshuttle-m-%s' % port
+        tproxy_chain = 'sshuttle-t-%s' % port
+        divert_chain = 'sshuttle-d-%s' % port
+
+        # basic cleanup/setup of chains
+        if ipt_chain_exists(family, table, mark_chain):
+            _ipt('-D', 'OUTPUT', '-j', mark_chain)
+            _ipt('-F', mark_chain)
+            _ipt('-X', mark_chain)
+
+        if ipt_chain_exists(family, table, tproxy_chain):
+            _ipt('-D', 'PREROUTING', '-j', tproxy_chain)
+            _ipt('-F', tproxy_chain)
+            _ipt('-X', tproxy_chain)
+
+        if ipt_chain_exists(family, table, divert_chain):
+            _ipt('-F', divert_chain)
+            _ipt('-X', divert_chain)
+
+    def is_supported(self):
+        if which("iptables") and which("ip6tables"):
+            return True
+        debug2("tproxy method not supported because 'iptables' "
+               "or 'ip6tables' commands are missing.\n")
+        return False

sshuttle/methods/windivert.py

@@ -0,0 +1,533 @@
+import os
+import sys
+from ipaddress import ip_address, ip_network
+import threading
+from collections import namedtuple
+import socket
+import subprocess
+import re
+from multiprocessing import shared_memory
+from struct import Struct
+from functools import wraps
+from enum import IntEnum
+import time
+import traceback
+
+
+from sshuttle.methods import BaseMethod
+from sshuttle.helpers import log, debug3, debug1, debug2, get_verbose_level, Fatal
+
+try:
+    # https://reqrypt.org/windivert-doc.html#divert_iphdr
+    # https://www.reqrypt.org/windivert-changelog.txt
+    import pydivert
+except ImportError:
+    raise Exception("Could not import pydivert module. windivert requires https://pypi.org/project/pydivert")
+
+
+ConnectionTuple = namedtuple(
+    "ConnectionTuple",
+    ["protocol", "ip_version", "src_addr", "src_port", "dst_addr", "dst_port", "state_epoch", "state"],
+)
+
+
+WINDIVERT_MAX_CONNECTIONS = int(os.environ.get('WINDIVERT_MAX_CONNECTIONS', 1024))
+
+
+class IPProtocol(IntEnum):
+    TCP = socket.IPPROTO_TCP
+    UDP = socket.IPPROTO_UDP
+
+    @property
+    def filter(self):
+        return "tcp" if self == IPProtocol.TCP else "udp"
+
+
+class IPFamily(IntEnum):
+    IPv4 = socket.AF_INET
+    IPv6 = socket.AF_INET6
+
+    @staticmethod
+    def from_ip_version(version):
+        return IPFamily.IPv6 if version == 4 else IPFamily.IPv4
+
+    @property
+    def filter(self):
+        return "ip" if self == socket.AF_INET else "ipv6"
+
+    @property
+    def version(self):
+        return 4 if self == socket.AF_INET else 6
+
+    @property
+    def loopback_addr(self):
+        return ip_address("127.0.0.1" if self == socket.AF_INET else "::1")
+
+
+class ConnState(IntEnum):
+    TCP_SYN_SENT = 11  # SYN sent
+    TCP_ESTABLISHED = 12  # SYN+ACK received
+    TCP_FIN_WAIT_1 = 91  # FIN sent
+    TCP_CLOSE_WAIT = 92  # FIN received
+
+    @staticmethod
+    def can_timeout(state):
+        return state in (ConnState.TCP_SYN_SENT, ConnState.TCP_FIN_WAIT_1, ConnState.TCP_CLOSE_WAIT)
+
+
+def repr_pkt(p):
+    try:
+        direction = p.direction.name
+        if p.is_loopback:
+            direction += "/lo"
+    except AttributeError:  # windiver > 2.0
+        direction = 'OUT' if p.address.Outbound == 1 else 'IN'
+        if p.address.Loopback == 1:
+            direction += '/lo'
+    r = f"{direction} {p.src_addr}:{p.src_port}->{p.dst_addr}:{p.dst_port}"
+    if p.tcp:
+        t = p.tcp
+        r += f" {len(t.payload)}B ("
+        r += "+".join(
+            f.upper() for f in ("fin", "syn", "rst", "psh", "ack", "urg", "ece", "cwr", "ns") if getattr(t, f)
+        )
+        r += f") SEQ#{t.seq_num}"
+        if t.ack:
+            r += f" ACK#{t.ack_num}"
+        r += f" WZ={t.window_size}"
+    else:
+        r += f" {p.udp=} {p.icmpv4=} {p.icmpv6=}"
+    return f"<Pkt {r}>"
+
+
+def synchronized_method(lock):
+    def decorator(method):
+        @wraps(method)
+        def wrapped(self, *args, **kwargs):
+            with getattr(self, lock):
+                return method(self, *args, **kwargs)
+
+        return wrapped
+
+    return decorator
+
+
+class ConnTrack:
+
+    _instance = None
+
+    def __new__(cls, *args, **kwargs):
+        if not cls._instance:
+            cls._instance = object.__new__(cls)
+            return cls._instance
+        raise RuntimeError("ConnTrack can not be instantiated multiple times")
+
+    def __init__(self, name, max_connections=0) -> None:
+        self.struct_full_tuple = Struct(">" + "".join(("B", "B", "16s", "H", "16s", "H", "L", "B")))
+        self.struct_src_tuple = Struct(">" + "".join(("B", "B", "16s", "H")))
+        self.struct_state_tuple = Struct(">" + "".join(("L", "B")))
+
+        try:
+            self.max_connections = max_connections
+            self.shm_list = shared_memory.ShareableList(
+                [bytes(self.struct_full_tuple.size) for _ in range(max_connections)], name=name
+            )
+            self.is_owner = True
+            self.next_slot = 0
+            self.used_slots = set()
+            self.rlock = threading.RLock()
+        except FileExistsError:
+            self.is_owner = False
+            self.shm_list = shared_memory.ShareableList(name=name)
+            self.max_connections = len(self.shm_list)
+
+        debug2(
+            f"ConnTrack: is_owner={self.is_owner} cap={len(self.shm_list)} item_sz={self.struct_full_tuple.size}B"
+            f"shm_name={self.shm_list.shm.name} shm_sz={self.shm_list.shm.size}B"
+        )
+
+    @synchronized_method("rlock")
+    def add(self, proto, src_addr, src_port, dst_addr, dst_port, state):
+        if not self.is_owner:
+            raise RuntimeError("Only owner can mutate ConnTrack")
+        if len(self.used_slots) >= self.max_connections:
+            raise RuntimeError(f"No slot available in ConnTrack {len(self.used_slots)}/{self.max_connections}")
+
+        if self.get(proto, src_addr, src_port):
+            return
+
+        for _ in range(self.max_connections):
+            if self.next_slot not in self.used_slots:
+                break
+            self.next_slot = (self.next_slot + 1) % self.max_connections
+        else:
+            raise RuntimeError("No slot available in ConnTrack")  # should not be here
+
+        src_addr = ip_address(src_addr)
+        dst_addr = ip_address(dst_addr)
+        assert src_addr.version == dst_addr.version
+        ip_version = src_addr.version
+        state_epoch = int(time.time())
+        entry = (proto, ip_version, src_addr.packed, src_port, dst_addr.packed, dst_port, state_epoch, state)
+        packed = self.struct_full_tuple.pack(*entry)
+        self.shm_list[self.next_slot] = packed
+        self.used_slots.add(self.next_slot)
+        proto = IPProtocol(proto)
+        debug3(
+            f"ConnTrack: added ({proto.name} {src_addr}:{src_port}->{dst_addr}:{dst_port} @{state_epoch}:{state.name}) to "
+            f"slot={self.next_slot} | #ActiveConn={len(self.used_slots)}"
+        )
+
+    @synchronized_method("rlock")
+    def update(self, proto, src_addr, src_port, state):
+        if not self.is_owner:
+            raise RuntimeError("Only owner can mutate ConnTrack")
+        src_addr = ip_address(src_addr)
+        packed = self.struct_src_tuple.pack(proto, src_addr.version, src_addr.packed, src_port)
+        for i in self.used_slots:
+            if self.shm_list[i].startswith(packed):
+                state_epoch = int(time.time())
+                self.shm_list[i] = self.shm_list[i][:-5] + self.struct_state_tuple.pack(state_epoch, state)
+                debug3(
+                    f"ConnTrack: updated ({proto.name} {src_addr}:{src_port} @{state_epoch}:{state.name}) from slot={i} | "
+                    f"#ActiveConn={len(self.used_slots)}"
+                )
+                return self._unpack(self.shm_list[i])
+            else:
+                debug3(
+                    f"ConnTrack: ({proto.name} src={src_addr}:{src_port}) is not found to update to {state.name} | "
+                    f"#ActiveConn={len(self.used_slots)}"
+                )
+
+    @synchronized_method("rlock")
+    def remove(self, proto, src_addr, src_port):
+        if not self.is_owner:
+            raise RuntimeError("Only owner can mutate ConnTrack")
+        src_addr = ip_address(src_addr)
+        packed = self.struct_src_tuple.pack(proto, src_addr.version, src_addr.packed, src_port)
+        for i in self.used_slots:
+            if self.shm_list[i].startswith(packed):
+                conn = self._unpack(self.shm_list[i])
+                self.shm_list[i] = b""
+                self.used_slots.remove(i)
+                debug3(
+                    f"ConnTrack: removed ({proto.name} src={src_addr}:{src_port}  state={conn.state.name}) from slot={i} | "
+                    f"#ActiveConn={len(self.used_slots)}"
+                )
+                return conn
+        else:
+            debug3(
+                f"ConnTrack: ({proto.name} src={src_addr}:{src_port}) is not found to remove |"
+                f" #ActiveConn={len(self.used_slots)}"
+            )
+
+    def get(self, proto, src_addr, src_port):
+        src_addr = ip_address(src_addr)
+        packed = self.struct_src_tuple.pack(proto, src_addr.version, src_addr.packed, src_port)
+        for entry in self.shm_list:
+            if entry and entry.startswith(packed):
+                return self._unpack(entry)
+
+    def dump(self):
+        for entry in self.shm_list:
+            if not entry:
+                continue
+            conn = self._unpack(entry)
+            proto, ip_version, src_addr, src_port, dst_addr, dst_port, state_epoch, state = conn
+            log(f"{proto.name}/{ip_version} {src_addr}:{src_port} -> {dst_addr}:{dst_port}  {state.name}@{state_epoch}")
+
+    @synchronized_method("rlock")
+    def gc(self, connection_timeout_sec=15):
+        # self.dump()
+        now = int(time.time())
+        n = 0
+        for i in tuple(self.used_slots):
+            state_packed = self.shm_list[i][-5:]
+            (state_epoch, state) = self.struct_state_tuple.unpack(state_packed)
+            if (now - state_epoch) < connection_timeout_sec:
+                continue
+            if ConnState.can_timeout(state):
+                conn = self._unpack(self.shm_list[i])
+                self.shm_list[i] = b""
+                self.used_slots.remove(i)
+                n += 1
+                debug3(
+                    f"ConnTrack: GC: removed ({conn.protocol.name} src={conn.src_addr}:{conn.src_port} state={conn.state.name})"
+                    f" from slot={i} | #ActiveConn={len(self.used_slots)}"
+                )
+        debug3(f"ConnTrack: GC: collected {n} connections | #ActiveConn={len(self.used_slots)}")
+
+    def _unpack(self, packed):
+        (
+            proto,
+            ip_version,
+            src_addr_packed,
+            src_port,
+            dst_addr_packed,
+            dst_port,
+            state_epoch,
+            state,
+        ) = self.struct_full_tuple.unpack(packed)
+        dst_addr = ip_address(dst_addr_packed if ip_version == 6 else dst_addr_packed[:4]).exploded
+        src_addr = ip_address(src_addr_packed if ip_version == 6 else src_addr_packed[:4]).exploded
+        proto = IPProtocol(proto)
+        state = ConnState(state)
+        return ConnectionTuple(proto, ip_version, src_addr, src_port, dst_addr, dst_port, state_epoch, state)
+
+    def __iter__(self):
+        def conn_iter():
+            for i in self.used_slots:
+                yield self._unpack(self.shm_list[i])
+
+        return conn_iter()
+
+    def __repr__(self):
+        return f"<ConnTrack(n={len(self.used_slots) if self.is_owner else '?'},cap={len(self.shm_list)},owner={self.is_owner})>"
+
+
+class Method(BaseMethod):
+
+    network_config = {}
+
+    def __init__(self, name):
+        super().__init__(name)
+
+    def _get_bind_address_for_port(self, port, family):
+        proto = "TCPv6" if family.version == 6 else "TCP"
+        for line in subprocess.check_output(["netstat", "-a", "-n", "-p", proto]).decode(errors='ignore').splitlines():
+            try:
+                _, local_addr, _, state, *_ = re.split(r"\s+", line.strip())
+            except ValueError:
+                continue
+            port_suffix = ":" + str(port)
+            if state == "LISTENING" and local_addr.endswith(port_suffix):
+                return ip_address(local_addr[:-len(port_suffix)].strip("[]"))
+        raise Fatal("Could not find listening address for {}/{}".format(port, proto))
+
+    def setup_firewall(self, proxy_port, dnsport, nslist, family, subnets, udp, user, group, tmark):
+        debug2(f"{proxy_port=}, {dnsport=}, {nslist=}, {family=}, {subnets=}, {udp=}, {user=}, {group=} {tmark=}")
+
+        if nslist or user or udp or group:
+            raise NotImplementedError("user, group, nslist, udp are not supported")
+
+        family = IPFamily(family)
+
+        proxy_ip = None
+        # using loopback only proxy binding won't work with windivert.
+        # See: https://github.com/basil00/Divert/issues/17#issuecomment-341100167 https://github.com/basil00/Divert/issues/82)
+        # As a workaround, finding another interface ip instead. (client should not bind proxy to loopback address)
+        proxy_bind_addr = self._get_bind_address_for_port(proxy_port, family)
+        if proxy_bind_addr.is_loopback:
+            raise Fatal("Windivert method requires proxy to be reachable by a non loopback address.")
+        if not proxy_bind_addr.is_unspecified:
+            proxy_ip = proxy_bind_addr
+        else:
+            local_addresses = [ip_address(info[4][0]) for info in socket.getaddrinfo(socket.gethostname(), 0, family=family)]
+            for addr in local_addresses:
+                if not addr.is_loopback and not addr.is_link_local:
+                    proxy_ip = addr
+                    break
+            else:
+                raise Fatal("Windivert method requires proxy to be reachable by a non loopback address."
+                            f"No address found for {family.name} in {local_addresses}")
+        debug2(f"Found non loopback address to connect to proxy: {proxy_ip}")
+        subnet_addresses = []
+        for (_, mask, exclude, network_addr, fport, lport) in subnets:
+            if fport and lport:
+                if lport > fport:
+                    raise Fatal("lport must be less than or equal to fport")
+                ports = (fport, lport)
+            else:
+                ports = None
+            subnet_addresses.append((ip_network(f"{network_addr}/{mask}"), ports, exclude))
+
+        self.network_config[family] = {
+            "subnets": subnet_addresses,
+            "nslist": nslist,
+            "proxy_addr": (proxy_ip, proxy_port)
+        }
+
+    def wait_for_firewall_ready(self, sshuttle_pid):
+        debug2(f"network_config={self.network_config}")
+        self.conntrack = ConnTrack(f"sshuttle-windivert-{sshuttle_pid}", WINDIVERT_MAX_CONNECTIONS)
+        if not self.conntrack.is_owner:
+            raise Fatal("ConnTrack should be owner in wait_for_firewall_ready()")
+        thread_target_funcs = (self._egress_divert, self._ingress_divert, self._connection_gc)
+        ready_events = []
+        for fn in thread_target_funcs:
+            ev = threading.Event()
+            ready_events.append(ev)
+
+            def _target():
+                try:
+                    fn(ev.set)
+                except Exception:
+                    debug2(f"thread {fn.__name__} exiting due to: " + traceback.format_exc())
+                    sys.stdin.close()  # this will exist main thread
+                    sys.stdout.close()
+
+            threading.Thread(name=fn.__name__, target=_target, daemon=True).start()
+        for ev in ready_events:
+            if not ev.wait(5):  # at most 5 sec
+                raise Fatal("timeout in wait_for_firewall_ready()")
+
+    def restore_firewall(self, port, family, udp, user, group):
+        pass
+
+    def get_supported_features(self):
+        result = super(Method, self).get_supported_features()
+        result.loopback_proxy_port = False
+        result.user = False
+        result.dns = False
+        # ipv6 only able to support with Windivert 2.x due to bugs in filter parsing
+        # TODO(nom3ad): Enable ipv6 once https://github.com/ffalcinelli/pydivert/pull/57 merged
+        result.ipv6 = False
+        return result
+
+    def get_tcp_dstip(self, sock):
+        if not hasattr(self, "conntrack"):
+            self.conntrack = ConnTrack(f"sshuttle-windivert-{os.getpid()}")
+            if self.conntrack.is_owner:
+                raise Fatal("ConnTrack should not be owner in get_tcp_dstip()")
+
+        src_addr, src_port = sock.getpeername()
+        c = self.conntrack.get(IPProtocol.TCP, src_addr, src_port)
+        if not c:
+            return (src_addr, src_port)
+        return (c.dst_addr, c.dst_port)
+
+    def is_supported(self):
+        if sys.platform == "win32":
+            return True
+        return False
+
+    def _egress_divert(self, ready_cb):
+        """divert outgoing packets to proxy"""
+        proto = IPProtocol.TCP
+        filter = f"outbound and {proto.filter}"
+        af_filters = []
+        for af, c in self.network_config.items():
+            subnet_include_filters = []
+            subnet_exclude_filters = []
+            for ip_net, ports, exclude in c["subnets"]:
+                first_ip = ip_net.network_address.exploded
+                last_ip = ip_net.broadcast_address.exploded
+                if first_ip == last_ip:
+                    _subnet_filter = f"{af.filter}.DstAddr=={first_ip}"
+                else:
+                    _subnet_filter = f"{af.filter}.DstAddr>={first_ip} and {af.filter}.DstAddr<={last_ip}"
+                if ports:
+                    if ports[0] == ports[1]:
+                        _subnet_filter += f" and {proto.filter}.DstPort=={ports[0]}"
+                    else:
+                        _subnet_filter += f" and tcp.DstPort>={ports[0]} and tcp.DstPort<={ports[1]}"
+                (subnet_exclude_filters if exclude else subnet_include_filters).append(f"({_subnet_filter})")
+            _af_filter = f"{af.filter}"
+            if subnet_include_filters:
+                _af_filter += f" and ({' or '.join(subnet_include_filters)})"
+            if subnet_exclude_filters:
+                # TODO(noma3ad) use not() operator with Windivert2 after upgrade
+                _af_filter += f" and (({' or '.join(subnet_exclude_filters)})? false : true)"
+            proxy_ip, proxy_port = c["proxy_addr"]
+            # Avoids proxy outbound traffic getting directed to itself
+            proxy_guard_filter = f"(({af.filter}.DstAddr=={proxy_ip.exploded} and tcp.DstPort=={proxy_port})? false : true)"
+            _af_filter += f" and {proxy_guard_filter}"
+            af_filters.append(_af_filter)
+        if not af_filters:
+            raise Fatal("At least one ipv4 or ipv6 subnet is expected")
+
+        filter = f"{filter} and ({' or '.join(af_filters)})"
+        debug1(f"[EGRESS] {filter=}")
+        with pydivert.WinDivert(filter, layer=pydivert.Layer.NETWORK, flags=pydivert.Flag.DEFAULT) as w:
+            proxy_ipv4, proxy_ipv6 = None, None
+            if IPFamily.IPv4 in self.network_config:
+                proxy_ipv4 = self.network_config[IPFamily.IPv4]["proxy_addr"]
+                proxy_ipv4 = proxy_ipv4[0].exploded, proxy_ipv4[1]
+            if IPFamily.IPv6 in self.network_config:
+                proxy_ipv6 = self.network_config[IPFamily.IPv6]["proxy_addr"]
+                proxy_ipv6 = proxy_ipv6[0].exploded, proxy_ipv6[1]
+            ready_cb()
+            verbose = get_verbose_level()
+            for pkt in w:
+                verbose >= 3 and debug3("[EGRESS] " + repr_pkt(pkt))
+                if pkt.tcp.syn and not pkt.tcp.ack:
+                    # SYN sent (start of 3-way handshake connection establishment from our side, we wait for SYN+ACK)
+                    self.conntrack.add(
+                        socket.IPPROTO_TCP,
+                        pkt.src_addr,
+                        pkt.src_port,
+                        pkt.dst_addr,
+                        pkt.dst_port,
+                        ConnState.TCP_SYN_SENT,
+                    )
+                if pkt.tcp.fin:
+                    # FIN sent (start of graceful close our side, and we wait for ACK)
+                    self.conntrack.update(IPProtocol.TCP, pkt.src_addr, pkt.src_port, ConnState.TCP_FIN_WAIT_1)
+                if pkt.tcp.rst:
+                    # RST sent (initiate abrupt connection teardown from our side, so we don't expect any reply)
+                    self.conntrack.remove(IPProtocol.TCP, pkt.src_addr, pkt.src_port)
+
+                # DNAT
+                if pkt.ipv4 and proxy_ipv4:
+                    pkt.dst_addr, pkt.tcp.dst_port = proxy_ipv4
+                if pkt.ipv6 and proxy_ipv6:
+                    pkt.dst_addr, pkt.tcp.dst_port = proxy_ipv6
+
+                # XXX: If we set loopback proxy address (DNAT), then we should do SNAT as well
+                #  by setting src_addr to loopback address.
+                # Otherwise injecting packet will be ignored by Windows network stack
+                #   as they packet has to cross public to private address space.
+                # See: https://github.com/basil00/Divert/issues/82
+                # Managing SNAT is more trickier, as we have to restore the original source IP address for reply packets.
+                # >>> pkt.dst_addr = proxy_ipv4
+                w.send(pkt, recalculate_checksum=True)
+
+    def _ingress_divert(self, ready_cb):
+        """handles incoming packets from proxy"""
+        proto = IPProtocol.TCP
+        # Windivert treats all local process traffic as outbound, regardless of origin external/loopback iface
+        direction = "outbound"
+        proxy_addr_filters = []
+        for af, c in self.network_config.items():
+            if not c["subnets"]:
+                continue
+            proxy_ip, proxy_port = c["proxy_addr"]
+            # "ip.SrcAddr=={hex(int(proxy_ip))}" # only Windivert >=2 supports this
+            proxy_addr_filters.append(f"{af.filter}.SrcAddr=={proxy_ip.exploded} and tcp.SrcPort=={proxy_port}")
+        if not proxy_addr_filters:
+            raise Fatal("At least one ipv4 or ipv6 address is expected")
+        filter = f"{direction} and {proto.filter} and ({' or '.join(proxy_addr_filters)})"
+        debug1(f"[INGRESS] {filter=}")
+        with pydivert.WinDivert(filter, layer=pydivert.Layer.NETWORK, flags=pydivert.Flag.DEFAULT) as w:
+            ready_cb()
+            verbose = get_verbose_level()
+            for pkt in w:
+                verbose >= 3 and debug3("[INGRESS] " + repr_pkt(pkt))
+                if pkt.tcp.syn and pkt.tcp.ack:
+                    # SYN+ACK received (connection established from proxy
+                    conn = self.conntrack.update(IPProtocol.TCP, pkt.dst_addr, pkt.dst_port, ConnState.TCP_ESTABLISHED)
+                elif pkt.tcp.rst:
+                    # RST received - Abrupt connection teardown initiated by proxy. Don't expect anymore packets
+                    conn = self.conntrack.remove(IPProtocol.TCP, pkt.dst_addr, pkt.dst_port)
+                # https://wiki.wireshark.org/TCP-4-times-close.md
+                elif pkt.tcp.fin and pkt.tcp.ack:
+                    # FIN+ACK received (Passive close by proxy. Don't expect any more packets. proxy expects an ACK)
+                    conn = self.conntrack.remove(IPProtocol.TCP, pkt.dst_addr, pkt.dst_port)
+                elif pkt.tcp.fin:
+                    # FIN received (proxy initiated graceful close.  Expect a final ACK for a FIN packet)
+                    conn = self.conntrack.update(IPProtocol.TCP, pkt.dst_addr, pkt.dst_port, ConnState.TCP_CLOSE_WAIT)
+                else:
+                    # data fragments and ACKs
+                    conn = self.conntrack.get(socket.IPPROTO_TCP, pkt.dst_addr, pkt.dst_port)
+                if not conn:
+                    verbose >= 2 and debug2("Unexpected packet: " + repr_pkt(pkt))
+                    continue
+                pkt.src_addr = conn.dst_addr
+                pkt.tcp.src_port = conn.dst_port
+                w.send(pkt, recalculate_checksum=True)
+
+    def _connection_gc(self, ready_cb):
+        ready_cb()
+        while True:
+            time.sleep(5)
+            self.conntrack.gc()

sshuttle/namespace.py

@@ -0,0 +1,40 @@
+import os
+import ctypes
+import ctypes.util
+
+from sshuttle.helpers import Fatal, debug1, debug2
+
+
+CLONE_NEWNET = 0x40000000
+NETNS_RUN_DIR = "/var/run/netns"
+
+
+def enter_namespace(namespace, namespace_pid):
+    if namespace:
+        namespace_dir = f'{NETNS_RUN_DIR}/{namespace}'
+    else:
+        namespace_dir = f'/proc/{namespace_pid}/ns/net'
+
+    if not os.path.exists(namespace_dir):
+        raise Fatal('The namespace %r does not exists.' % namespace_dir)
+
+    debug2('loading libc')
+    libc = ctypes.CDLL(ctypes.util.find_library("c"), use_errno=True)
+
+    default_errcheck = libc.setns.errcheck
+
+    def errcheck(ret, *args):
+        if ret == -1:
+            e = ctypes.get_errno()
+            raise Fatal(e, os.strerror(e))
+        if default_errcheck:
+            return default_errcheck(ret, *args)
+
+    libc.setns.errcheck = errcheck  # type: ignore
+
+    debug1('Entering namespace %r' % namespace_dir)
+
+    with open(namespace_dir) as fd:
+        libc.setns(fd.fileno(), CLONE_NEWNET)
+
+    debug1('Namespace %r successfully set' % namespace_dir)

sshuttle/options.py

@@ -0,0 +1,488 @@
+import re
+import socket
+import sys
+from argparse import ArgumentParser, Action, ArgumentTypeError as Fatal
+
+from sshuttle import __version__
+
+
+# Subnet file, supporting empty lines and hash-started comment lines
+def parse_subnetport_file(s):
+    try:
+        handle = open(s, 'r')
+    except OSError:
+        raise Fatal('Unable to open subnet file: %s' % s)
+
+    raw_config_lines = handle.readlines()
+    subnets = []
+    for _, line in enumerate(raw_config_lines):
+        line = line.strip()
+        if not line:
+            continue
+        if line[0] == '#':
+            continue
+        subnets.append(parse_subnetport(line))
+
+    return subnets
+
+
+# 1.2.3.4/5:678, 1.2.3.4:567, 1.2.3.4/16 or just 1.2.3.4
+# [1:2::3/64]:456, [1:2::3]:456, 1:2::3/64 or just 1:2::3
+# example.com:123 or just example.com
+#
+# In addition, the port number can be specified as a range:
+# 1.2.3.4:8000-8080.
+#
+# Can return multiple matches if the domain name used in the request
+# has multiple IP addresses.
+def parse_subnetport(s):
+
+    if s.count(':') > 1:
+        rx = r'(?:\[?(?:\*\.)?([\w\:]+)(?:/(\d+))?]?)(?::(\d+)(?:-(\d+))?)?$'
+    else:
+        rx = r'((?:\*\.)?[\w\.\-]+)(?:/(\d+))?(?::(\d+)(?:-(\d+))?)?$'
+
+    m = re.match(rx, s)
+    if not m:
+        raise Fatal('%r is not a valid address/mask:port format' % s)
+
+    # Ports range from fport to lport. If only one port is specified,
+    # fport is defined and lport is None.
+    #
+    # cidr is the mask defined with the slash notation
+    host, cidr, fport, lport = m.groups()
+    try:
+        addrinfo = socket.getaddrinfo(host, 0, 0, socket.SOCK_STREAM)
+    except socket.gaierror:
+        raise Fatal('Unable to resolve address: %s' % host)
+
+    # If the address is a domain with multiple IPs and a mask is also
+    # provided, proceed cautiously:
+    if cidr is not None:
+        addr_v6 = [a for a in addrinfo if a[0] == socket.AF_INET6]
+        addr_v4 = [a for a in addrinfo if a[0] == socket.AF_INET]
+
+        # Refuse to proceed if IPv4 and IPv6 addresses are present:
+        if len(addr_v6) > 0 and len(addr_v4) > 0:
+            raise Fatal("%s has IPv4 and IPv6 addresses, so the mask "
+                        "of /%s is not supported. Specify the IP "
+                        "addresses directly if you wish to specify "
+                        "a mask." % (host, cidr))
+
+        # Warn if a domain has multiple IPs of the same type (IPv4 vs
+        # IPv6) and the mask is applied to all of the IPs.
+        if len(addr_v4) > 1 or len(addr_v6) > 1:
+            print("WARNING: %s has multiple IP addresses. The "
+                  "mask of /%s is applied to all of the addresses."
+                  % (host, cidr))
+
+    rv = []
+    for a in addrinfo:
+        family, _, _, _, addr = a
+
+        # Largest possible slash value we can use with this IP:
+        max_cidr = 32 if family == socket.AF_INET else 128
+
+        if cidr is None:  # if no mask, use largest mask
+            cidr_to_use = max_cidr
+        else:   # verify user-provided mask is appropriate
+            cidr_to_use = int(cidr)
+            if not 0 <= cidr_to_use <= max_cidr:
+                raise Fatal('Slash in CIDR notation (/%d) is '
+                            'not between 0 and %d'
+                            % (cidr_to_use, max_cidr))
+
+        rv.append((family, addr[0], cidr_to_use,
+                   int(fport or 0), int(lport or fport or 0)))
+
+    return rv
+
+
+# 1.2.3.4:567 or just 1.2.3.4 or just 567
+# [1:2::3]:456 or [1:2::3] or just [::]:567
+# example.com:123 or just example.com
+def parse_ipport(s):
+    s = str(s)
+    if s.isdigit():
+        rx = r'()(\d+)$'
+    elif ']' in s:
+        rx = r'(?:\[([^]]+)])(?::(\d+))?$'
+    else:
+        rx = r'([\w\.\-]+)(?::(\d+))?$'
+
+    m = re.match(rx, s)
+    if not m:
+        raise Fatal('%r is not a valid IP:port format' % s)
+
+    host, port = m.groups()
+    host = host or '0.0.0.0'
+    port = int(port or 0)
+
+    try:
+        addrinfo = socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM)
+    except socket.gaierror:
+        raise Fatal('Unable to resolve address: %s' % host)
+
+    if len(addrinfo) > 1:
+        print("WARNING: Host %s has more than one IP, only using one of them."
+              % host)
+
+    family, _, _, _, addr = min(addrinfo)
+    # Note: addr contains (ip, port)
+    return (family,) + addr[:2]
+
+
+def parse_list(lst):
+    """Parse a comma separated string into a list."""
+    return re.split(r'[\s,]+', lst.strip()) if lst else []
+
+
+def parse_namespace(namespace):
+    try:
+        assert re.fullmatch(
+            r'(@?[a-z_A-Z]\w+(?:\.@?[a-z_A-Z]\w+)*)', namespace)
+        return namespace
+    except AssertionError:
+        raise Fatal("%r is not a valid namespace name." % namespace)
+
+
+class Concat(Action):
+    def __init__(self, option_strings, dest, nargs=None, **kwargs):
+        if nargs is not None:
+            raise ValueError("nargs not supported")
+        super(Concat, self).__init__(option_strings, dest, **kwargs)
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        curr_value = getattr(namespace, self.dest, None) or []
+        setattr(namespace, self.dest, curr_value + values)
+
+
+# Override one function in the ArgumentParser so that we can have
+# better control for how we parse files containing arguments. We
+# expect one argument per line, but strip whitespace/quotes from the
+# beginning/end of the lines.
+class MyArgumentParser(ArgumentParser):
+    def convert_arg_line_to_args(self, arg_line):
+        # Ignore comments
+        if arg_line.startswith("#"):
+            return []
+
+        # strip whitespace at beginning and end of line
+        arg_line = arg_line.strip()
+
+        # When copying parameters from the command line to a file,
+        # some users might copy the quotes they used on the command
+        # line into the config file. We ignore these if the line
+        # starts and ends with the same quote.
+        if arg_line.startswith("'") and arg_line.endswith("'") or \
+           arg_line.startswith('"') and arg_line.endswith('"'):
+            arg_line = arg_line[1:-1]
+
+        return [arg_line]
+
+
+parser = MyArgumentParser(
+    prog="sshuttle",
+    usage="%(prog)s [-l [ip:]port] -r [user@]sshserver[:port] <subnets...>",
+    fromfile_prefix_chars="@"
+)
+parser.add_argument(
+    "subnets",
+    metavar="IP/MASK[:PORT[-PORT]]...",
+    nargs="*",
+    type=parse_subnetport,
+    help="""
+    capture and forward traffic to these subnets (whitespace separated)
+    """
+)
+parser.add_argument(
+    "-l", "--listen",
+    metavar="[IP:]PORT",
+    help="""
+    transproxy to this ip address and port number
+    """
+)
+parser.add_argument(
+    "-H", "--auto-hosts",
+    action="store_true",
+    help="""
+    continuously scan for remote hostnames and update local /etc/hosts as
+    they are found
+    """
+)
+parser.add_argument(
+    "-N", "--auto-nets",
+    action="store_true",
+    help="""
+    automatically determine subnets to route
+    """
+)
+parser.add_argument(
+    "--dns",
+    action="store_true",
+    help="""
+    capture local DNS requests and forward to the remote DNS server
+    """
+)
+parser.add_argument(
+    "--ns-hosts",
+    metavar="IP[,IP]",
+    default=[],
+    type=parse_list,
+    help="""
+    capture and forward DNS requests made to the following servers
+    (comma separated)
+    """
+)
+parser.add_argument(
+    "--to-ns",
+    metavar="IP[:PORT]",
+    type=parse_ipport,
+    help="""
+    the DNS server to forward requests to; defaults to servers in
+    /etc/resolv.conf on remote side if not given.
+    """
+)
+
+if sys.platform == 'win32':
+    method_choices = ["auto", "windivert"]
+else:
+    method_choices = ["auto", "nft", "nat", "tproxy", "pf", "ipfw"]
+
+parser.add_argument(
+    "--method",
+    choices=method_choices,
+    metavar="TYPE",
+    default="auto",
+    help="""
+    %(choices)s
+    """
+)
+parser.add_argument(
+    "--python",
+    metavar="PATH",
+    help="""
+    path to python interpreter on the remote server
+    """
+)
+parser.add_argument(
+    "-r", "--remote",
+    metavar="[USERNAME[:PASSWORD]@]ADDR[:PORT]",
+    help="""
+    ssh hostname (and optional username and password) of remote %(prog)s server
+    """
+)
+parser.add_argument(
+    "-x", "--exclude",
+    metavar="IP/MASK[:PORT[-PORT]]",
+    action="append",
+    default=[],
+    type=parse_subnetport,
+    help="""
+    exclude this subnet (can be used more than once)
+    """
+)
+parser.add_argument(
+    "-X", "--exclude-from",
+    metavar="PATH",
+    action=Concat,
+    dest="exclude",
+    type=parse_subnetport_file,
+    help="""
+    exclude the subnets in a file (whitespace separated)
+    """
+)
+parser.add_argument(
+    "-v", "--verbose",
+    action="count",
+    default=0,
+    help="""
+    increase debug message verbosity (can be used more than once)
+    """
+)
+parser.add_argument(
+    "-V", "--version",
+    action="version",
+    version=__version__,
+    help="""
+    print the %(prog)s version number and exit
+    """
+)
+parser.add_argument(
+    "-e", "--ssh-cmd",
+    metavar="CMD",
+    default="ssh",
+    help="""
+    the command to use to connect to the remote [%(default)s]
+    """
+)
+parser.add_argument(
+    "--no-cmd-delimiter",
+    action="store_false",
+    dest="add_cmd_delimiter",
+    help="""
+    do not add a double dash before the python command
+    """
+)
+parser.add_argument(
+    "--remote-shell",
+    metavar="PROGRAM",
+    help="""
+    alternate remote shell program instead of defacto posix shell.
+    For Windows targets it would be either `cmd` or `powershell` unless something like git-bash is in use.
+    """
+)
+parser.add_argument(
+    "--seed-hosts",
+    metavar="HOSTNAME[,HOSTNAME]",
+    default=[],
+    help="""
+    comma-separated list of hostnames for initial scan (may be used with
+    or without --auto-hosts)
+    """
+)
+parser.add_argument(
+    "--no-latency-control",
+    action="store_false",
+    dest="latency_control",
+    help="""
+    sacrifice latency to improve bandwidth benchmarks
+    """
+)
+parser.add_argument(
+    "--latency-buffer-size",
+    metavar="SIZE",
+    type=int,
+    default=32768,
+    dest="latency_buffer_size",
+    help="""
+    size of latency control buffer
+    """
+)
+parser.add_argument(
+    "--wrap",
+    metavar="NUM",
+    type=int,
+    help="""
+    restart counting channel numbers after this number (for testing)
+    """
+)
+parser.add_argument(
+    "--disable-ipv6",
+    action="store_true",
+    help="""
+    disable IPv6 support
+    """
+)
+parser.add_argument(
+    "-D", "--daemon",
+    action="store_true",
+    help="""
+    run in the background as a daemon
+    """
+)
+parser.add_argument(
+    "-s", "--subnets",
+    metavar="PATH",
+    action=Concat,
+    dest="subnets_file",
+    default=[],
+    type=parse_subnetport_file,
+    help="""
+    file where the subnets are stored, instead of on the command line
+    """
+)
+parser.add_argument(
+    "--syslog",
+    action="store_true",
+    help="""
+    send log messages to syslog (default if you use --daemon)
+    """
+)
+parser.add_argument(
+    "--pidfile",
+    metavar="PATH",
+    default="./sshuttle.pid",
+    help="""
+    pidfile name (only if using --daemon) [%(default)s]
+    """
+)
+parser.add_argument(
+    "--user",
+    help="""
+    apply all the rules only to this linux user
+    """
+)
+parser.add_argument(
+    "--group",
+    help="""
+    apply all the rules only to this linux group
+    """
+)
+parser.add_argument(
+    "--firewall",
+    action="store_true",
+    help="""
+    (internal use only)
+    """
+)
+parser.add_argument(
+    "--hostwatch",
+    action="store_true",
+    help="""
+    (internal use only)
+    """
+)
+parser.add_argument(
+    "--sudoers-no-modify",
+    action="store_true",
+    help="""
+    Prints a sudo configuration to STDOUT which allows a user to
+    run sshuttle without a password. This option is INSECURE because,
+    with some cleverness, it also allows the user to run any command
+    as root without a password. The output also includes a suggested
+    method for you to install the configuration.
+    """
+)
+parser.add_argument(
+    "--sudoers-user",
+    default="",
+    help="""
+    Set the user name or group with %%group_name for passwordless operation.
+    Default is the current user. Only works with the --sudoers-no-modify option.
+    """
+)
+parser.add_argument(
+    "--no-sudo-pythonpath",
+    action="store_false",
+    dest="sudo_pythonpath",
+    help="""
+    do not set PYTHONPATH when invoking sudo
+    """
+)
+parser.add_argument(
+    "-t", "--tmark",
+    metavar="[MARK]",
+    default="0x01",
+    help="""
+    tproxy optional traffic mark with provided MARK value in
+    hexadecimal (default '0x01')
+    """
+)
+
+if sys.platform == 'linux':
+    net_ns_group = parser.add_mutually_exclusive_group(
+        required=False)
+
+    net_ns_group.add_argument(
+        '--namespace',
+        type=parse_namespace,
+        help="Run inside of a net namespace with the given name."
+    )
+    net_ns_group.add_argument(
+        '--namespace-pid',
+        type=int,
+        help="""
+        Run inside the net namespace used by the process with
+        the given pid."""
+    )

sshuttle/sdnotify.py

@@ -0,0 +1,63 @@
+"""When sshuttle is run via a systemd service file, we can communicate
+to systemd about the status of the sshuttle process. In particular, we
+can send READY status to tell systemd that sshuttle has completed
+startup and send STOPPING to indicate that sshuttle is beginning
+shutdown.
+
+For details, see:
+https://www.freedesktop.org/software/systemd/man/sd_notify.html
+"""
+
+import socket
+import os
+
+from sshuttle.helpers import debug1
+
+
+def _notify(message):
+    """Send a notification message to systemd."""
+    addr = os.environ.get("NOTIFY_SOCKET", None)
+
+    if not addr or len(addr) == 1 or addr[0] not in ('/', '@'):
+        return False
+
+    addr = '\0' + addr[1:] if addr[0] == '@' else addr
+
+    try:
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+    except (OSError, IOError) as e:
+        debug1("Error creating socket to notify systemd: %s" % e)
+        return False
+
+    if not message:
+        return False
+
+    assert isinstance(message, bytes)
+
+    try:
+        return (sock.sendto(message, addr) > 0)
+    except (OSError, IOError) as e:
+        debug1("Error notifying systemd: %s" % e)
+        return False
+
+
+def send(*messages):
+    """Send multiple messages to systemd."""
+    return _notify(b'\n'.join(messages))
+
+
+def ready():
+    """Constructs a message that is appropriate to send upon completion of
+sshuttle startup."""
+    return b"READY=1"
+
+
+def stop():
+    """Constructs a message that is appropriate to send when sshuttle is
+beginning to shutdown."""
+    return b"STOPPING=1"
+
+
+def status(message):
+    """Constructs a status message to be sent to systemd."""
+    return b"STATUS=%s" % message.encode('utf8')

sshuttle/server.py

@@ -0,0 +1,442 @@
+import re
+import struct
+import socket
+import traceback
+import time
+import sys
+import os
+import io
+
+
+import sshuttle.ssnet as ssnet
+import sshuttle.helpers as helpers
+import sshuttle.hostwatch as hostwatch
+import subprocess as ssubprocess
+from sshuttle.ssnet import Handler, Proxy, Mux, MuxWrapper
+from sshuttle.helpers import b, log, debug1, debug2, debug3, Fatal, \
+    get_random_nameserver, which, get_env, SocketRWShim
+
+
+def _ipmatch(ipstr):
+    # FIXME: IPv4 only
+    if ipstr == 'default':
+        ipstr = '0.0.0.0/0'
+    m = re.match(r'^(\d+(\.\d+(\.\d+(\.\d+)?)?)?)(?:/(\d+))?$', ipstr)
+    if m:
+        g = m.groups()
+        ips = g[0]
+        width = int(g[4] or 32)
+        if g[1] is None:
+            ips += '.0.0.0'
+            width = min(width, 8)
+        elif g[2] is None:
+            ips += '.0.0'
+            width = min(width, 16)
+        elif g[3] is None:
+            ips += '.0'
+            width = min(width, 24)
+        return (struct.unpack('!I', socket.inet_aton(ips))[0], width)
+
+
+def _ipstr(ip, width):
+    # FIXME: IPv4 only
+    if width >= 32:
+        return ip
+    else:
+        return "%s/%d" % (ip, width)
+
+
+def _maskbits(netmask):
+    # FIXME: IPv4 only
+    if not netmask:
+        return 32
+    for i in range(32):
+        if netmask[0] & _shl(1, i):
+            return 32 - i
+    return 0
+
+
+def _shl(n, bits):
+    return n * int(2 ** bits)
+
+
+def _route_netstat(line):
+    cols = line.split(None)
+    if len(cols) < 3:
+        return None, None
+    ipw = _ipmatch(cols[0])
+    maskw = _ipmatch(cols[2])  # linux only
+    mask = _maskbits(maskw)   # returns 32 if maskw is null
+    return ipw, mask
+
+
+def _route_iproute(line):
+    ipm = line.split(None, 1)[0]
+    if '/' not in ipm:
+        return None, None
+    ip, mask = ipm.split('/')
+    ipw = _ipmatch(ip)
+    return ipw, int(mask)
+
+
+def _route_windows(line):
+    if " On-link " not in line:
+        return None, None
+    dest, net_mask = re.split(r'\s+', line.strip())[:2]
+    if net_mask == "255.255.255.255":
+        return None, None
+    for p in ('127.', '0.', '224.', '169.254.'):
+        if dest.startswith(p):
+            return None, None
+    ipw = _ipmatch(dest)
+    mask = _maskbits(_ipmatch(net_mask))
+    return ipw, mask
+
+
+def _list_routes(argv, extract_route):
+    # FIXME: IPv4 only
+    p = ssubprocess.Popen(argv, stdout=ssubprocess.PIPE, env=get_env())
+    routes = []
+    for line in p.stdout:
+        if not line.strip():
+            continue
+        ipw, mask = extract_route(line.decode("ASCII"))
+        if not ipw:
+            continue
+        width = min(ipw[1], mask)
+        ip = ipw[0] & _shl(_shl(1, width) - 1, 32 - width)
+        routes.append(
+            (socket.AF_INET, socket.inet_ntoa(struct.pack('!I', ip)), width))
+    rv = p.wait()
+    if rv != 0:
+        log('WARNING: %r returned %d' % (argv, rv))
+
+    return routes
+
+
+def list_routes():
+    if sys.platform == 'win32':
+        routes = _list_routes(['route', 'PRINT', '-4'], _route_windows)
+    else:
+        if which('ip'):
+            routes = _list_routes(['ip', 'route'], _route_iproute)
+        elif which('netstat'):
+            routes = _list_routes(['netstat', '-rn'], _route_netstat)
+        else:
+            log('WARNING: Neither "ip" nor "netstat" were found on the server. '
+                '--auto-nets feature will not work.')
+            routes = []
+
+    for (family, ip, width) in routes:
+        if not ip.startswith('0.') and not ip.startswith('127.'):
+            yield (family, ip, width)
+
+
+def _exc_dump():
+    exc_info = sys.exc_info()
+    return ''.join(traceback.format_exception(*exc_info))
+
+
+def start_hostwatch(seed_hosts, auto_hosts):
+    s1, s2 = socket.socketpair()
+    pid = os.fork()
+    if not pid:
+        # child
+        rv = 99
+        try:
+            try:
+                s2.close()
+                os.dup2(s1.fileno(), 1)
+                os.dup2(s1.fileno(), 0)
+                s1.close()
+                rv = hostwatch.hw_main(seed_hosts, auto_hosts) or 0
+            except Exception:
+                log('%s' % _exc_dump())
+                rv = 98
+        finally:
+            os._exit(rv)
+    s1.close()
+    return pid, s2
+
+
+class Hostwatch:
+
+    def __init__(self):
+        self.pid = 0
+        self.sock = None
+
+
+class DnsProxy(Handler):
+
+    def __init__(self, mux, chan, request, to_nameserver):
+        Handler.__init__(self, [])
+        self.timeout = time.time() + 30
+        self.mux = mux
+        self.chan = chan
+        self.tries = 0
+        self.request = request
+        self.peers = {}
+        self.to_ns_peer = None
+        self.to_ns_port = None
+        if to_nameserver is None:
+            self.to_nameserver = None
+        else:
+            self.to_ns_peer, self.to_ns_port = to_nameserver.split("@")
+            self.to_nameserver = self._addrinfo(self.to_ns_peer,
+                                                self.to_ns_port)
+        self.try_send()
+
+    @staticmethod
+    def _addrinfo(peer, port):
+        if int(port) == 0:
+            port = 53
+        family, _, _, _, sockaddr = socket.getaddrinfo(peer, port)[0]
+        return (family, sockaddr)
+
+    def try_send(self):
+        if self.tries >= 3:
+            return
+        self.tries += 1
+
+        if self.to_nameserver is None:
+            _, peer = get_random_nameserver()
+            port = 53
+        else:
+            peer = self.to_ns_peer
+            port = int(self.to_ns_port)
+
+        family, sockaddr = self._addrinfo(peer, port)
+        sock = socket.socket(family, socket.SOCK_DGRAM)
+        sock.connect(sockaddr)
+
+        self.peers[sock] = peer
+
+        debug2('DNS: sending to %r:%d (try %d)' % (peer, port, self.tries))
+        try:
+            sock.send(self.request)
+            self.socks.append(sock)
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            if e.args[0] in ssnet.NET_ERRS:
+                # might have been spurious; try again.
+                # Note: these errors sometimes are reported by recv(),
+                # and sometimes by send().  We have to catch both.
+                debug2('DNS send to %r: %s' % (peer, e))
+                self.try_send()
+                return
+            else:
+                log('DNS send to %r: %s' % (peer, e))
+                return
+
+    def callback(self, sock):
+        peer = self.peers[sock]
+
+        try:
+            data = sock.recv(4096)
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            self.socks.remove(sock)
+            del self.peers[sock]
+
+            if e.args[0] in ssnet.NET_ERRS:
+                # might have been spurious; try again.
+                # Note: these errors sometimes are reported by recv(),
+                # and sometimes by send().  We have to catch both.
+                debug2('DNS recv from %r: %s' % (peer, e))
+                self.try_send()
+                return
+            else:
+                log('DNS recv from %r: %s' % (peer, e))
+                return
+        debug2('DNS response: %d bytes' % len(data))
+        self.mux.send(self.chan, ssnet.CMD_DNS_RESPONSE, data)
+        self.ok = False
+
+
+class UdpProxy(Handler):
+
+    def __init__(self, mux, chan, family):
+        sock = socket.socket(family, socket.SOCK_DGRAM)
+        Handler.__init__(self, [sock])
+        self.timeout = time.time() + 30
+        self.mux = mux
+        self.chan = chan
+        self.sock = sock
+
+    def send(self, dstip, data):
+        debug2('UDP: sending to %r port %d' % dstip)
+        try:
+            self.sock.sendto(data, dstip)
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            log('UDP send to %r port %d: %s' % (dstip[0], dstip[1], e))
+            return
+
+    def callback(self, sock):
+        try:
+            data, peer = sock.recvfrom(4096)
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            log('UDP recv from %r port %d: %s' % (peer[0], peer[1], e))
+            return
+        debug2('UDP response: %d bytes' % len(data))
+        hdr = b("%s,%r," % (peer[0], peer[1]))
+        self.mux.send(self.chan, ssnet.CMD_UDP_DATA, hdr + data)
+
+
+def main(latency_control, latency_buffer_size, auto_hosts, to_nameserver,
+         auto_nets):
+    try:
+        helpers.logprefix = ' s: '
+
+        debug1('latency control setting = %r' % latency_control)
+        if latency_buffer_size:
+            import sshuttle.ssnet as ssnet
+            ssnet.LATENCY_BUFFER_SIZE = latency_buffer_size
+
+        # synchronization header
+        sys.stdout.write('\0\0SSHUTTLE0001')
+        sys.stdout.flush()
+
+        handlers = []
+        # get unbuffered stdin and stdout in binary mode. Equivalent to stdin.buffer/stdout.buffer (Only available in Python 3)
+        r, w = io.FileIO(0, mode='r'), io.FileIO(1, mode='w')
+        if sys.platform == 'win32':
+            def _deferred_exit():
+                time.sleep(1)  # give enough time to write logs to stderr
+                os._exit(23)
+            shim = SocketRWShim(r, w, on_end=_deferred_exit)
+            mux = Mux(*shim.makefiles())
+        else:
+            mux = Mux(r, w)
+        handlers.append(mux)
+
+        debug1('auto-nets:' + str(auto_nets))
+        if auto_nets:
+            routes = list(list_routes())
+            debug1('available routes:')
+            for r in routes:
+                debug1('  %d/%s/%d' % r)
+        else:
+            routes = []
+
+        routepkt = ''
+        for r in routes:
+            routepkt += '%d,%s,%d\n' % r
+        mux.send(0, ssnet.CMD_ROUTES, b(routepkt))
+
+        hw = Hostwatch()
+        hw.leftover = b('')
+
+        def hostwatch_ready(sock):
+            assert hw.pid
+            content = hw.sock.recv(4096)
+            if content:
+                lines = (hw.leftover + content).split(b('\n'))
+                if lines[-1]:
+                    # no terminating newline: entry isn't complete yet!
+                    hw.leftover = lines.pop()
+                    lines.append(b(''))
+                else:
+                    hw.leftover = b('')
+                mux.send(0, ssnet.CMD_HOST_LIST, b('\n').join(lines))
+            else:
+                raise Fatal('hostwatch process died')
+
+        def got_host_req(data):
+            if not hw.pid:
+                (hw.pid, hw.sock) = start_hostwatch(
+                        data.decode("ASCII").strip().split(), auto_hosts)
+                handlers.append(Handler(socks=[hw.sock],
+                                        callback=hostwatch_ready))
+        mux.got_host_req = got_host_req
+
+        def new_channel(channel, data):
+            (family, dstip, dstport) = data.decode("ASCII").split(',', 2)
+            family = int(family)
+            # AF_INET is the same constant on Linux and BSD but AF_INET6
+            # is different. As the client and server can be running on
+            # different platforms we can not just set the socket family
+            # to what comes in the wire.
+            if family != socket.AF_INET:
+                family = socket.AF_INET6
+            dstport = int(dstport)
+            outwrap = ssnet.connect_dst(family, dstip, dstport)
+            handlers.append(Proxy(MuxWrapper(mux, channel), outwrap))
+        mux.new_channel = new_channel
+
+        dnshandlers = {}
+
+        def dns_req(channel, data):
+            debug2('Incoming DNS request channel=%d.' % channel)
+            h = DnsProxy(mux, channel, data, to_nameserver)
+            handlers.append(h)
+            dnshandlers[channel] = h
+        mux.got_dns_req = dns_req
+
+        udphandlers = {}
+
+        def udp_req(channel, cmd, data):
+            debug2('Incoming UDP request channel=%d, cmd=%d' %
+                   (channel, cmd))
+            if cmd == ssnet.CMD_UDP_DATA:
+                (dstip, dstport, data) = data.split(b(','), 2)
+                dstport = int(dstport)
+                debug2('is incoming UDP data. %r %d.' % (dstip, dstport))
+                h = udphandlers[channel]
+                h.send((dstip, dstport), data)
+            elif cmd == ssnet.CMD_UDP_CLOSE:
+                debug2('is incoming UDP close')
+                h = udphandlers[channel]
+                h.ok = False
+                del mux.channels[channel]
+
+        def udp_open(channel, data):
+            debug2('Incoming UDP open.')
+            family = int(data)
+            mux.channels[channel] = lambda cmd, data: udp_req(channel, cmd,
+                                                              data)
+            if channel in udphandlers:
+                raise Fatal('UDP connection channel %d already open' %
+                            channel)
+            else:
+                h = UdpProxy(mux, channel, family)
+                handlers.append(h)
+                udphandlers[channel] = h
+        mux.got_udp_open = udp_open
+
+        while mux.ok:
+            if hw.pid:
+                assert hw.pid > 0
+                (rpid, rv) = os.waitpid(hw.pid, os.WNOHANG)
+                if rpid:
+                    raise Fatal(
+                        'hostwatch exited unexpectedly: code 0x%04x' % rv)
+
+            ssnet.runonce(handlers, mux)
+            if latency_control:
+                mux.check_fullness()
+
+            if dnshandlers:
+                now = time.time()
+                remove = []
+                for channel, h in dnshandlers.items():
+                    if h.timeout < now or not h.ok:
+                        debug3('expiring dnsreqs channel=%d' % channel)
+                        remove.append(channel)
+                        h.ok = False
+                for channel in remove:
+                    del dnshandlers[channel]
+            if udphandlers:
+                remove = []
+                for channel, h in udphandlers.items():
+                    if not h.ok:
+                        debug3('expiring UDP channel=%d' % channel)
+                        remove.append(channel)
+                        h.ok = False
+                for channel in remove:
+                    del udphandlers[channel]
+
+    except Fatal as e:
+        log('fatal: %s' % e)
+        sys.exit(99)

sshuttle/ssh.py

@@ -0,0 +1,255 @@
+import sys
+import os
+import re
+import socket
+import zlib
+import importlib
+import importlib.util
+import subprocess as ssubprocess
+import shlex
+from shlex import quote
+import ipaddress
+from urllib.parse import urlparse
+
+import sshuttle.helpers as helpers
+from sshuttle.helpers import debug2, which, get_path, SocketRWShim, Fatal
+
+
+def get_module_source(name):
+    spec = importlib.util.find_spec(name)
+    with open(spec.origin, "rt") as f:
+        return f.read().encode("utf-8")
+
+
+def empackage(z, name, data=None):
+    if not data:
+        data = get_module_source(name)
+    content = z.compress(data)
+    content += z.flush(zlib.Z_SYNC_FLUSH)
+
+    return b'%s\n%d\n%s' % (name.encode("ASCII"), len(content), content)
+
+
+def parse_hostport(rhostport):
+    """
+    parses the given rhostport variable, looking like this:
+
+            [username[:password]@]host[:port]
+
+    if only host is given, can be a hostname, IPv4/v6 address or a ssh alias
+    from ~/.ssh/config
+
+    and returns a tuple (username, password, port, host)
+    """
+    # leave use of default port to ssh command to prevent overwriting
+    # ports configured in ~/.ssh/config when no port is given
+    if rhostport is None or len(rhostport) == 0:
+        return None, None, None, None
+    port = None
+    username = None
+    password = None
+    host = rhostport
+
+    if "@" in host:
+        # split username (and possible password) from the host[:port]
+        username, host = host.rsplit("@", 1)
+        # Fix #410 bad username error detect
+        if ":" in username:
+            # this will even allow for the username to be empty
+            username, password = username.split(":", 1)
+
+    if ":" in host:
+        # IPv6 address and/or got a port specified
+
+        # If it is an IPv6 address with port specification,
+        # then it will look like: [::1]:22
+
+        try:
+            # try to parse host as an IP address,
+            # if that works it is an IPv6 address
+            host = str(ipaddress.ip_address(host))
+        except ValueError:
+            # if that fails parse as URL to get the port
+            parsed = urlparse('//{}'.format(host))
+            try:
+                host = str(ipaddress.ip_address(parsed.hostname))
+            except ValueError:
+                # else if both fails, we have a hostname with port
+                host = parsed.hostname
+            port = parsed.port
+
+    if password is None or len(password) == 0:
+        password = None
+
+    return username, password, port, host
+
+
+def connect(ssh_cmd, rhostport, python, stderr, add_cmd_delimiter, remote_shell, options):
+    username, password, port, host = parse_hostport(rhostport)
+    if username:
+        rhost = "{}@{}".format(username, host)
+    else:
+        rhost = host
+
+    z = zlib.compressobj(1)
+    content = get_module_source('sshuttle.assembler')
+    optdata = ''.join("%s=%r\n" % (k, v) for (k, v) in list(options.items()))
+    optdata = optdata.encode("UTF8")
+    content2 = (empackage(z, 'sshuttle') +
+                empackage(z, 'sshuttle.cmdline_options', optdata) +
+                empackage(z, 'sshuttle.helpers') +
+                empackage(z, 'sshuttle.ssnet') +
+                empackage(z, 'sshuttle.hostwatch') +
+                empackage(z, 'sshuttle.server') +
+                b"\n")
+
+    # If the exec() program calls sys.exit(), it should exit python
+    # and the sys.exit(98) call won't be reached (so we try to only
+    # exit that way in the server). However, if the code that we
+    # exec() simply returns from main, then we will return from
+    # exec(). If the server's python process dies, it should stop
+    # executing and also won't reach sys.exit(98).
+    #
+    # So, we shouldn't reach sys.exit(98) and we certainly shouldn't
+    # reach it immediately after trying to start the server.
+    pyscript = r"""
+                import sys, os;
+                verbosity=%d;
+                stdin = os.fdopen(0, 'rb');
+                exec(compile(stdin.read(%d), 'assembler.py', 'exec'));
+                sys.exit(98);
+                """ % (helpers.verbose or 0, len(content))
+    pyscript = re.sub(r'\s+', ' ', pyscript.strip())
+
+    if not rhost:
+        # ignore the --python argument when running locally; we already know
+        # which python version works.
+        argv = [sys.executable, '-c', pyscript]
+    else:
+        if ssh_cmd:
+            sshl = shlex.split(ssh_cmd)
+        else:
+            sshl = ['ssh']
+        if port is not None:
+            portl = ["-p", str(port)]
+        else:
+            portl = []
+        if remote_shell == "cmd":
+            pycmd = '"%s" -c "%s"' % (python or 'python', pyscript)
+        elif remote_shell == "powershell":
+            for c in ('\'', ' ', ';', '(', ')', ','):
+                pyscript = pyscript.replace(c, '`' + c)
+            pycmd = '%s -c %s' % (python or 'python', pyscript)
+        else:  # posix shell expected
+            if python:
+                pycmd = '"%s" -c "%s"' % (python, pyscript)
+            else:
+                # By default, we run the following code in a shell.
+                # However, with restricted shells and other unusual
+                # situations, there can be trouble. See the RESTRICTED
+                # SHELL section in "man bash" for more information. The
+                # code makes many assumptions:
+                #
+                # (1) That /bin/sh exists and that we can call it.
+                # Restricted shells often do *not* allow you to run
+                # programs specified with an absolute path like /bin/sh.
+                # Either way, if there is trouble with this, it should
+                # return error code 127.
+                #
+                # (2) python3 or python exists in the PATH and is
+                # executable. If they aren't, then exec won't work (see (4)
+                # below).
+                #
+                # (3) In /bin/sh, that we can redirect stderr in order to
+                # hide the version that "python3 -V" might print (some
+                # restricted shells don't allow redirection, see
+                # RESTRICTED SHELL section in 'man bash'). However, if we
+                # are in a restricted shell, we'd likely have trouble with
+                # assumption (1) above.
+                #
+                # (4) The 'exec' command should work except if we failed
+                # to exec python because it doesn't exist or isn't
+                # executable OR if exec isn't allowed (some restricted
+                # shells don't allow exec). If the exec succeeded, it will
+                # not return and not get to the "exit 97" command. If exec
+                # does return, we exit with code 97.
+                #
+                # Specifying the exact python program to run with --python
+                # avoids many of the issues above. However, if
+                # you have a restricted shell on remote, you may only be
+                # able to run python if it is in your PATH (and you can't
+                # run programs specified with an absolute path). In that
+                # case, sshuttle might not work at all since it is not
+                # possible to run python on the remote machine---even if
+                # it is present.
+                devnull = '/dev/null'
+                pycmd = ("P=python3; $P -V 2>%s || P=python; "
+                         "exec \"$P\" -c %s; exit 97") % \
+                    (devnull, quote(pyscript))
+                pycmd = ("/bin/sh -c {}".format(quote(pycmd)))
+
+        if password is not None:
+            os.environ['SSHPASS'] = str(password)
+            argv = (["sshpass", "-e"] + sshl +
+                    portl + [rhost])
+
+        else:
+            argv = (sshl + portl + [rhost])
+
+        if add_cmd_delimiter:
+            argv += ['--', pycmd]
+        else:
+            argv += [pycmd]
+
+    # Our which() function searches for programs in get_path()
+    # directories (which include PATH). This step isn't strictly
+    # necessary if ssh is already in the user's PATH, but it makes the
+    # error message friendlier if the user incorrectly passes in a
+    # custom ssh command that we cannot find.
+    abs_path = which(argv[0])
+    if abs_path is None:
+        raise Fatal("Failed to find '%s' in path %s" % (argv[0], get_path()))
+    argv[0] = abs_path
+
+    if sys.platform != 'win32':
+        (s1, s2) = socket.socketpair()
+        pstdin, pstdout = os.dup(s1.fileno()), os.dup(s1.fileno())
+
+        def preexec_fn():
+            # runs in the child process
+            s2.close()
+        s1.close()
+
+        def get_server_io():
+            os.close(pstdin)
+            os.close(pstdout)
+            return s2.makefile("rb", buffering=0), s2.makefile("wb", buffering=0)
+    else:
+        # In Windows CPython, BSD sockets are not supported as subprocess stdio
+        # and select.select() used in ssnet.py won't work on Windows pipes.
+        # So we have to use both socketpair (for select.select) and pipes (for subprocess.Popen) together
+        # along with reader/writer threads to stream data between them
+        # NOTE: Their could be a better way. Need to investigate further on this.
+        #   Either to use sockets as stdio for subprocess. Or to use pipes but with a select() alternative
+        #   https://stackoverflow.com/questions/4993119/redirect-io-of-process-to-windows-socket
+
+        pstdin = ssubprocess.PIPE
+        pstdout = ssubprocess.PIPE
+
+        preexec_fn = None
+
+        def get_server_io():
+            shim = SocketRWShim(p.stdout, p.stdin, on_end=lambda: p.terminate())
+            return shim.makefiles()
+
+    # See: stackoverflow.com/questions/48671215/howto-workaround-of-close-fds-true-and-redirect-stdout-stderr-on-windows
+    close_fds = False if sys.platform == 'win32' else True
+
+    debug2("executing: %r" % argv)
+    p = ssubprocess.Popen(argv, stdin=pstdin, stdout=pstdout, preexec_fn=preexec_fn,
+                          close_fds=close_fds, stderr=stderr, bufsize=0)
+
+    rfile, wfile = get_server_io()
+    wfile.write(content)
+    wfile.write(content2)
+    return p, rfile, wfile

sshuttle/ssnet.py

@@ -1,49 +1,71 @@
-import struct, socket, errno, select
-if not globals().get('skip_imports'):
-    from helpers import *
-    
-# these don't exist in the socket module in python 2.3!
+import sys
+import struct
+import socket
+import errno
+import select
+import os
+
+from sshuttle.helpers import b, log, debug1, debug2, debug3, Fatal, set_non_blocking_io
+
+MAX_CHANNEL = 65535
+LATENCY_BUFFER_SIZE = 32768
+
 SHUT_RD = 0
 SHUT_WR = 1
 SHUT_RDWR = 2
 
-
 HDR_LEN = 8
 
-
 CMD_EXIT = 0x4200
 CMD_PING = 0x4201
 CMD_PONG = 0x4202
-CMD_CONNECT = 0x4203
-# CMD_CLOSE = 0x4204   # never used - removed
-CMD_EOF = 0x4205
-CMD_DATA = 0x4206
+CMD_TCP_CONNECT = 0x4203
+CMD_TCP_STOP_SENDING = 0x4204
+CMD_TCP_EOF = 0x4205
+CMD_TCP_DATA = 0x4206
 CMD_ROUTES = 0x4207
 CMD_HOST_REQ = 0x4208
 CMD_HOST_LIST = 0x4209
+CMD_DNS_REQ = 0x420a
+CMD_DNS_RESPONSE = 0x420b
+CMD_UDP_OPEN = 0x420c
+CMD_UDP_DATA = 0x420d
+CMD_UDP_CLOSE = 0x420e
 
 cmd_to_name = {
     CMD_EXIT: 'EXIT',
     CMD_PING: 'PING',
     CMD_PONG: 'PONG',
-    CMD_CONNECT: 'CONNECT',
-    CMD_EOF: 'EOF',
-    CMD_DATA: 'DATA',
+    CMD_TCP_CONNECT: 'TCP_CONNECT',
+    CMD_TCP_STOP_SENDING: 'TCP_STOP_SENDING',
+    CMD_TCP_EOF: 'TCP_EOF',
+    CMD_TCP_DATA: 'TCP_DATA',
     CMD_ROUTES: 'ROUTES',
     CMD_HOST_REQ: 'HOST_REQ',
     CMD_HOST_LIST: 'HOST_LIST',
+    CMD_DNS_REQ: 'DNS_REQ',
+    CMD_DNS_RESPONSE: 'DNS_RESPONSE',
+    CMD_UDP_OPEN: 'UDP_OPEN',
+    CMD_UDP_DATA: 'UDP_DATA',
+    CMD_UDP_CLOSE: 'UDP_CLOSE',
 }
-    
 
 
-def _add(l, elem):
-    if not elem in l:
-        l.append(elem)
+NET_ERRS = [errno.ECONNREFUSED, errno.ETIMEDOUT,
+            errno.EHOSTUNREACH, errno.ENETUNREACH,
+            errno.EHOSTDOWN, errno.ENETDOWN,
+            errno.ENETUNREACH, errno.ECONNABORTED,
+            errno.ECONNRESET]
 
 
-def _fds(l):
+def _add(socks, elem):
+    if elem not in socks:
+        socks.append(elem)
+
+
+def _fds(socks):
     out = []
-    for i in l:
+    for i in socks:
         try:
             out.append(i.fileno())
         except AttributeError:
@@ -55,11 +77,13 @@ def _fds(l):
 def _nb_clean(func, *args):
     try:
         return func(*args)
-    except OSError, e:
+    except (OSError, socket.error):
+        # Note: In python2 socket.error != OSError (In python3, they are same)
+        _, e = sys.exc_info()[:2]
         if e.errno not in (errno.EWOULDBLOCK, errno.EAGAIN):
             raise
         else:
-            debug3('%s: err was: %s\n' % (func.__name__, e))
+            debug3('%s: err was: %s' % (func.__name__, e))
             return None
 
 
@@ -68,18 +92,26 @@ def _try_peername(sock):
         pn = sock.getpeername()
         if pn:
             return '%s:%s' % (pn[0], pn[1])
-    except socket.error, e:
-        if e.args[0] not in (errno.ENOTCONN, errno.ENOTSOCK):
+    except socket.error:
+        _, e = sys.exc_info()[:2]
+        if e.args[0] == errno.EINVAL:
+            pass
+        elif e.args[0] not in (errno.ENOTCONN, errno.ENOTSOCK):
             raise
+    except AttributeError:
+        pass
     return 'unknown'
 
 
 _swcount = 0
+
+
 class SockWrapper:
+
     def __init__(self, rsock, wsock, connect_to=None, peername=None):
         global _swcount
         _swcount += 1
-        debug3('creating new SockWrapper (%d now exist\n)' % _swcount)
+        debug3('creating new SockWrapper (%d now exist)' % _swcount)
         self.exc = None
         self.rsock = rsock
         self.wsock = wsock
@@ -92,9 +124,9 @@ class SockWrapper:
     def __del__(self):
         global _swcount
         _swcount -= 1
-        debug1('%r: deleting (%d remain)\n' % (self, _swcount))
+        debug1('%r: deleting (%d remain)' % (self, _swcount))
         if self.exc:
-            debug1('%r: error was: %r\n' % (self, self.exc))
+            debug1('%r: error was: %s' % (self, self.exc))
 
     def __repr__(self):
         if self.rsock == self.wsock:
@@ -106,6 +138,8 @@ class SockWrapper:
     def seterr(self, e):
         if not self.exc:
             self.exc = e
+        self.nowrite()
+        self.noread()
 
     def try_connect(self):
         if self.connect_to and self.shut_write:
@@ -114,21 +148,47 @@ class SockWrapper:
         if not self.connect_to:
             return  # already connected
         self.rsock.setblocking(False)
-        debug3('%r: trying connect to %r\n' % (self, self.connect_to))
+        debug3('%r: trying connect to %r' % (self, self.connect_to))
         try:
             self.rsock.connect(self.connect_to)
             # connected successfully (Linux)
             self.connect_to = None
-        except socket.error, e:
-            debug3('%r: connect result: %r\n' % (self, e))
+        except socket.error:
+            _, e = sys.exc_info()[:2]
+            debug3('%r: connect result: %s' % (self, e))
+            if e.args[0] == errno.EINVAL:
+                # this is what happens when you call connect() on a socket
+                # that is now connected but returned EINPROGRESS last time,
+                # on BSD, on python pre-2.5.1.  We need to use getsockopt()
+                # to get the "real" error.  Later pythons do this
+                # automatically, so this code won't run.
+                realerr = self.rsock.getsockopt(socket.SOL_SOCKET,
+                                                socket.SO_ERROR)
+                e = socket.error(realerr, os.strerror(realerr))
+                debug3('%r: fixed connect result: %s' % (self, e))
             if e.args[0] in [errno.EINPROGRESS, errno.EALREADY]:
                 pass  # not connected yet
+            elif sys.platform == 'win32' and e.args[0] == errno.WSAEWOULDBLOCK:  # 10035
+                pass  # not connected yet
+            elif e.args[0] == 0:
+                if sys.platform == 'win32':
+                    # On Windows "real" error of EINVAL could be 0, when socket is in connecting state
+                    pass
+                else:
+                    # connected successfully (weird Linux bug?)
+                    # Sometimes Linux seems to return EINVAL when it isn't
+                    # invalid.  This *may* be caused by a race condition
+                    # between connect() and getsockopt(SO_ERROR) (ie. it
+                    # finishes connecting in between the two, so there is no
+                    # longer an error).  However, I'm not sure of that.
+                    #
+                    # I did get at least one report that the problem went away
+                    # when we added this, however.
+                    self.connect_to = None
             elif e.args[0] == errno.EISCONN:
-                # connected successfully (BSD)
+                # connected successfully (BSD + Windows)
                 self.connect_to = None
-            elif e.args[0] in [errno.ECONNREFUSED, errno.ETIMEDOUT,
-                               errno.EHOSTUNREACH, errno.ENETUNREACH,
-                               errno.EACCES, errno.EPERM]:
+            elif e.args[0] in NET_ERRS + [errno.EACCES, errno.EPERM]:
                 # a "normal" kind of error
                 self.connect_to = None
                 self.seterr(e)
@@ -137,20 +197,21 @@ class SockWrapper:
 
     def noread(self):
         if not self.shut_read:
-            debug2('%r: done reading\n' % self)
+            debug2('%r: done reading' % self)
             self.shut_read = True
-            #self.rsock.shutdown(SHUT_RD)  # doesn't do anything anyway
-        
+
     def nowrite(self):
         if not self.shut_write:
-            debug2('%r: done writing\n' % self)
+            debug2('%r: done writing' % self)
             self.shut_write = True
             try:
                 self.wsock.shutdown(SHUT_WR)
-            except socket.error, e:
-                self.seterr(e)
+            except socket.error:
+                _, e = sys.exc_info()[:2]
+                self.seterr('nowrite: %s' % e)
 
-    def too_full(self):
+    @staticmethod
+    def too_full():
         return False  # fullness is determined by the socket's select() state
 
     def uwrite(self, buf):
@@ -158,16 +219,20 @@ class SockWrapper:
             return 0  # still connecting
         self.wsock.setblocking(False)
         try:
-            return _nb_clean(os.write, self.wsock.fileno(), buf)
-        except OSError, e:
-            # unexpected error... stream is dead
-            self.seterr(e)
-            self.nowrite()
-            self.noread()
-            return 0
-        
+            return _nb_clean(self.wsock.send, buf)
+        except OSError:
+            _, e = sys.exc_info()[:2]
+            if e.errno == errno.EPIPE:
+                debug1('%r: uwrite: got EPIPE' % self)
+                self.nowrite()
+                return 0
+            else:
+                # unexpected error... stream is dead
+                self.seterr('uwrite: %s' % e)
+                return 0
+
     def write(self, buf):
-        assert(buf)
+        assert buf
         return self.uwrite(buf)
 
     def uread(self):
@@ -177,10 +242,11 @@ class SockWrapper:
             return
         self.rsock.setblocking(False)
         try:
-            return _nb_clean(os.read, self.rsock.fileno(), 65536)
-        except OSError, e:
-            self.seterr(e)
-            return '' # unexpected error... we'll call it EOF
+            return _nb_clean(self.rsock.recv, 65536)
+        except OSError:
+            _, e = sys.exc_info()[:2]
+            self.seterr('uread: %s' % e)
+            return b('')  # unexpected error... we'll call it EOF
 
     def fill(self):
         if self.buf:
@@ -188,7 +254,7 @@ class SockWrapper:
         rb = self.uread()
         if rb:
             self.buf.append(rb)
-        if rb == '':  # empty string means EOF; None means temporarily empty
+        if rb == b(''):  # empty string means EOF; None means temporarily empty
             self.noread()
 
     def copy_to(self, outwrap):
@@ -202,7 +268,8 @@ class SockWrapper:
 
 
 class Handler:
-    def __init__(self, socks = None, callback = None):
+
+    def __init__(self, socks=None, callback=None):
         self.ok = True
         self.socks = socks or []
         if callback:
@@ -212,18 +279,19 @@ class Handler:
         for i in self.socks:
             _add(r, i)
 
-    def callback(self):
-        log('--no callback defined-- %r\n' % self)
-        (r,w,x) = select.select(self.socks, [], [], 0)
+    def callback(self, sock):
+        log('--no callback defined-- %r' % self)
+        (r, _, _) = select.select(self.socks, [], [], 0)
         for s in r:
             v = s.recv(4096)
             if not v:
-                log('--closed-- %r\n' % self)
+                log('--closed-- %r' % self)
                 self.socks = []
                 self.ok = False
 
 
 class Proxy(Handler):
+
     def __init__(self, wrap1, wrap2):
         Handler.__init__(self, [wrap1.rsock, wrap1.wsock,
                                 wrap2.rsock, wrap2.wsock])
@@ -231,6 +299,11 @@ class Proxy(Handler):
         self.wrap2 = wrap2
 
     def pre_select(self, r, w, x):
+        if self.wrap1.shut_write:
+            self.wrap2.noread()
+        if self.wrap2.shut_write:
+            self.wrap1.noread()
+
         if self.wrap1.connect_to:
             _add(w, self.wrap1.rsock)
         elif self.wrap1.buf:
@@ -247,7 +320,7 @@ class Proxy(Handler):
         elif not self.wrap2.shut_read:
             _add(r, self.wrap2.rsock)
 
-    def callback(self):
+    def callback(self, sock):
         self.wrap1.try_connect()
         self.wrap2.try_connect()
         self.wrap1.fill()
@@ -261,79 +334,87 @@ class Proxy(Handler):
             self.wrap2.buf = []
             self.wrap2.noread()
         if (self.wrap1.shut_read and self.wrap2.shut_read and
-            not self.wrap1.buf and not self.wrap2.buf):
+                not self.wrap1.buf and not self.wrap2.buf):
             self.ok = False
             self.wrap1.nowrite()
             self.wrap2.nowrite()
 
 
 class Mux(Handler):
-    def __init__(self, rsock, wsock):
-        Handler.__init__(self, [rsock, wsock])
-        self.rsock = rsock
-        self.wsock = wsock
-        self.new_channel = self.got_routes = None
+
+    def __init__(self, rfile, wfile):
+        Handler.__init__(self, [rfile, wfile])
+        self.rfile = rfile
+        self.wfile = wfile
+        self.new_channel = self.got_dns_req = self.got_routes = None
+        self.got_udp_open = self.got_udp_data = self.got_udp_close = None
         self.got_host_req = self.got_host_list = None
         self.channels = {}
         self.chani = 0
         self.want = 0
-        self.inbuf = ''
+        self.inbuf = b('')
         self.outbuf = []
         self.fullness = 0
         self.too_full = False
-        self.send(0, CMD_PING, 'chicken')
+        self.send(0, CMD_PING, b('chicken'))
 
     def next_channel(self):
         # channel 0 is special, so we never allocate it
-        for timeout in xrange(1024):
+        for _ in range(1024):
             self.chani += 1
-            if self.chani > 65535:
+            if self.chani > MAX_CHANNEL:
                 self.chani = 1
             if not self.channels.get(self.chani):
                 return self.chani
 
     def amount_queued(self):
         total = 0
-        for b in self.outbuf:
-            total += len(b)
+        for byte in self.outbuf:
+            total += len(byte)
         return total
-            
+
     def check_fullness(self):
-        if self.fullness > 32768:
+        if self.fullness > LATENCY_BUFFER_SIZE:
             if not self.too_full:
-                self.send(0, CMD_PING, 'rttest')
+                self.send(0, CMD_PING, b('rttest'))
             self.too_full = True
-        #ob = []
-        #for b in self.outbuf:
-        #    (s1,s2,c) = struct.unpack('!ccH', b[:4])
-        #    ob.append(c)
-        #log('outbuf: %d %r\n' % (self.amount_queued(), ob))
-        
+
     def send(self, channel, cmd, data):
-        data = str(data)
-        assert(len(data) <= 65535)
-        p = struct.pack('!ccHHH', 'S', 'S', channel, cmd, len(data)) + data
+        assert isinstance(data, bytes)
+        assert len(data) <= 65535
+        p = struct.pack('!ccHHH', b('S'), b('S'), channel, cmd, len(data)) \
+            + data
         self.outbuf.append(p)
-        debug2(' > channel=%d cmd=%s len=%d (fullness=%d)\n'
-               % (channel, cmd_to_name.get(cmd,hex(cmd)),
+        debug2(' > channel=%d cmd=%s len=%d (fullness=%d)'
+               % (channel, cmd_to_name.get(cmd, hex(cmd)),
                   len(data), self.fullness))
+        # debug3('>>> data: %r' % data)
         self.fullness += len(data)
 
     def got_packet(self, channel, cmd, data):
-        debug2('<  channel=%d cmd=%s len=%d\n' 
-               % (channel, cmd_to_name.get(cmd,hex(cmd)), len(data)))
+        debug2('<  channel=%d cmd=%s len=%d'
+               % (channel, cmd_to_name.get(cmd, hex(cmd)), len(data)))
+        # debug3('<<< data: %r' % data)
         if cmd == CMD_PING:
             self.send(0, CMD_PONG, data)
         elif cmd == CMD_PONG:
-            debug2('received PING response\n')
+            debug2('received PING response')
             self.too_full = False
             self.fullness = 0
         elif cmd == CMD_EXIT:
             self.ok = False
-        elif cmd == CMD_CONNECT:
-            assert(not self.channels.get(channel))
+        elif cmd == CMD_TCP_CONNECT:
+            assert not self.channels.get(channel)
             if self.new_channel:
                 self.new_channel(channel, data)
+        elif cmd == CMD_DNS_REQ:
+            assert not self.channels.get(channel)
+            if self.got_dns_req:
+                self.got_dns_req(channel, data)
+        elif cmd == CMD_UDP_OPEN:
+            assert not self.channels.get(channel)
+            if self.got_udp_open:
+                self.got_udp_open(channel, data)
         elif cmd == CMD_ROUTES:
             if self.got_routes:
                 self.got_routes(data)
@@ -350,41 +431,48 @@ class Mux(Handler):
             else:
                 raise Exception('got CMD_HOST_LIST without got_host_list?')
         else:
-            callback = self.channels[channel]
-            callback(cmd, data)
+            callback = self.channels.get(channel)
+            if not callback:
+                log('warning: closed channel %d got cmd=%s len=%d'
+                    % (channel, cmd_to_name.get(cmd, hex(cmd)), len(data)))
+            else:
+                callback(cmd, data)
 
     def flush(self):
-        self.wsock.setblocking(False)
+        set_non_blocking_io(self.wfile.fileno())
         if self.outbuf and self.outbuf[0]:
-            wrote = _nb_clean(os.write, self.wsock.fileno(), self.outbuf[0])
-            debug2('mux wrote: %r/%d\n' % (wrote, len(self.outbuf[0])))
+            wrote = _nb_clean(self.wfile.write, self.outbuf[0])
+            # self.wfile.flush()
+            debug2('mux wrote: %r/%d' % (wrote, len(self.outbuf[0])))
             if wrote:
                 self.outbuf[0] = self.outbuf[0][wrote:]
         while self.outbuf and not self.outbuf[0]:
             self.outbuf[0:1] = []
 
     def fill(self):
-        self.rsock.setblocking(False)
+        set_non_blocking_io(self.rfile.fileno())
         try:
-            b = _nb_clean(os.read, self.rsock.fileno(), 32768)
-        except OSError, e:
+            # If LATENCY_BUFFER_SIZE is inappropriately large, we will
+            # get a MemoryError here. Read no more than 1MiB.
+            read = _nb_clean(self.rfile.read, min(1048576, LATENCY_BUFFER_SIZE))
+            debug2('mux read: %r' % len(read))
+        except OSError:
+            _, e = sys.exc_info()[:2]
             raise Fatal('other end: %r' % e)
-        #log('<<< %r\n' % b)
-        if b == '': # EOF
+        # log('<<< %r' % b)
+        if read == b(''):  # EOF
             self.ok = False
-        if b:
-            self.inbuf += b
+        if read:
+            self.inbuf += read
 
     def handle(self):
         self.fill()
-        #log('inbuf is: (%d,%d) %r\n'
-        #     % (self.want, len(self.inbuf), self.inbuf))
         while 1:
             if len(self.inbuf) >= (self.want or HDR_LEN):
-                (s1,s2,channel,cmd,datalen) = \
+                (s1, s2, channel, cmd, datalen) = \
                     struct.unpack('!ccHHH', self.inbuf[:HDR_LEN])
-                assert(s1 == 'S')
-                assert(s2 == 'S')
+                assert s1 == b('S')
+                assert s2 == b('S')
                 self.want = datalen + HDR_LEN
             if self.want and len(self.inbuf) >= self.want:
                 data = self.inbuf[HDR_LEN:self.want]
@@ -395,47 +483,60 @@ class Mux(Handler):
                 break
 
     def pre_select(self, r, w, x):
-        _add(r, self.rsock)
+        _add(r, self.rfile)
         if self.outbuf:
-            _add(w, self.wsock)
+            _add(w, self.wfile)
 
-    def callback(self):
-        (r,w,x) = select.select([self.rsock], [self.wsock], [], 0)
-        if self.rsock in r:
+    def callback(self, sock):
+        (r, w, _) = select.select([self.rfile], [self.wfile], [], 0)
+        if self.rfile in r:
             self.handle()
-        if self.outbuf and self.wsock in w:
+        if self.outbuf and self.wfile in w:
             self.flush()
 
 
 class MuxWrapper(SockWrapper):
+
     def __init__(self, mux, channel):
-        SockWrapper.__init__(self, mux.rsock, mux.wsock)
+        SockWrapper.__init__(self, mux.rfile, mux.wfile)
         self.mux = mux
         self.channel = channel
         self.mux.channels[channel] = self.got_packet
         self.socks = []
-        debug2('new channel: %d\n' % channel)
+        debug2('new channel: %d' % channel)
 
     def __del__(self):
         self.nowrite()
         SockWrapper.__del__(self)
 
     def __repr__(self):
-        return 'SW%r:Mux#%d' % (self.peername,self.channel)
+        return 'SW%r:Mux#%d' % (self.peername, self.channel)
 
     def noread(self):
         if not self.shut_read:
+            self.mux.send(self.channel, CMD_TCP_STOP_SENDING, b(''))
+            self.setnoread()
+
+    def setnoread(self):
+        if not self.shut_read:
+            debug2('%r: done reading' % self)
             self.shut_read = True
             self.maybe_close()
 
     def nowrite(self):
         if not self.shut_write:
+            self.mux.send(self.channel, CMD_TCP_EOF, b(''))
+            self.setnowrite()
+
+    def setnowrite(self):
+        if not self.shut_write:
+            debug2('%r: done writing' % self)
             self.shut_write = True
-            self.mux.send(self.channel, CMD_EOF, '')
             self.maybe_close()
 
     def maybe_close(self):
         if self.shut_read and self.shut_write:
+            debug2('%r: closing connection' % self)
             # remove the mux's reference to us.  The python garbage collector
             # will then be able to reap our object.
             self.mux.channels[self.channel] = None
@@ -448,57 +549,61 @@ class MuxWrapper(SockWrapper):
             return 0  # too much already enqueued
         if len(buf) > 2048:
             buf = buf[:2048]
-        self.mux.send(self.channel, CMD_DATA, buf)
+        self.mux.send(self.channel, CMD_TCP_DATA, buf)
         return len(buf)
 
     def uread(self):
         if self.shut_read:
-            return '' # EOF
+            return b('')  # EOF
         else:
             return None  # no data available right now
 
     def got_packet(self, cmd, data):
-        if cmd == CMD_EOF:
-            self.noread()
-        elif cmd == CMD_DATA:
+        if cmd == CMD_TCP_EOF:
+            # Remote side already knows the status - set flag but don't notify
+            self.setnoread()
+        elif cmd == CMD_TCP_STOP_SENDING:
+            # Remote side already knows the status - set flag but don't notify
+            self.setnowrite()
+        elif cmd == CMD_TCP_DATA:
             self.buf.append(data)
         else:
-            raise Exception('unknown command %d (%d bytes)' 
+            raise Exception('unknown command %d (%d bytes)'
                             % (cmd, len(data)))
 
 
-def connect_dst(ip, port):
-    debug2('Connecting to %s:%d\n' % (ip, port))
-    outsock = socket.socket()
-    outsock.setsockopt(socket.SOL_IP, socket.IP_TTL, 42)
+def connect_dst(family, ip, port):
+    debug2('Connecting to %s:%d' % (ip, port))
+    outsock = socket.socket(family)
+
     return SockWrapper(outsock, outsock,
-                       connect_to = (ip,port),
-                       peername = '%s:%d' % (ip,port))
+                       connect_to=(ip, port),
+                       peername='%s:%d' % (ip, port))
 
 
 def runonce(handlers, mux):
     r = []
     w = []
     x = []
-    to_remove = filter(lambda s: not s.ok, handlers)
+    to_remove = [s for s in handlers if not s.ok]
     for h in to_remove:
         handlers.remove(h)
 
     for s in handlers:
-        s.pre_select(r,w,x)
-    debug2('Waiting: %d r=%r w=%r x=%r (fullness=%d/%d)\n' 
-            % (len(handlers), _fds(r), _fds(w), _fds(x),
+        s.pre_select(r, w, x)
+    debug2('Waiting: %d r=%r w=%r x=%r (fullness=%d/%d)'
+           % (len(handlers), _fds(r), _fds(w), _fds(x),
                mux.fullness, mux.too_full))
-    (r,w,x) = select.select(r,w,x)
-    debug2('  Ready: %d r=%r w=%r x=%r\n' 
-        % (len(handlers), _fds(r), _fds(w), _fds(x)))
-    ready = r+w+x
+    (r, w, x) = select.select(r, w, x)
+    debug2('  Ready: %d r=%r w=%r x=%r'
+           % (len(handlers), _fds(r), _fds(w), _fds(x)))
+    ready = r + w + x
     did = {}
     for h in handlers:
         for s in h.socks:
             if s in ready:
-                h.callback()
+                h.callback(s)
                 did[s] = 1
     for s in ready:
-        if not s in did:
+        if s not in did:
             raise Fatal('socket %r was not used by any handler' % s)

sshuttle/ssyslog.py

@@ -0,0 +1,31 @@
+import sys
+import os
+import subprocess as ssubprocess
+
+
+_p = None
+
+
+def start_syslog():
+    global _p
+    with open(os.devnull, 'w') as devnull:
+        _p = ssubprocess.Popen(
+            ['logger', '-p', 'daemon.err', '-t', 'sshuttle'],
+            stdin=ssubprocess.PIPE,
+            stdout=devnull,
+            stderr=devnull
+        )
+
+
+def close_stdin():
+    sys.stdin.close()
+
+
+def stdout_to_syslog():
+    sys.stdout.flush()
+    os.dup2(_p.stdin.fileno(), sys.stdout.fileno())
+
+
+def stderr_to_syslog():
+    sys.stderr.flush()
+    os.dup2(_p.stdin.fileno(), sys.stderr.fileno())

sshuttle/sudoers.py

@@ -0,0 +1,45 @@
+import os
+import sys
+import getpass
+from uuid import uuid4
+
+
+def build_config(user_name):
+    """Generates a sudoers configuration to allow passwordless execution of sshuttle."""
+
+    argv0 = os.path.abspath(sys.argv[0])
+    is_python_script = argv0.endswith('.py')
+    executable = f"{sys.executable} {argv0}" if is_python_script else argv0
+    dist_packages = os.path.dirname(os.path.abspath(__file__))
+    cmd_alias = f"SSHUTTLE{uuid4().hex[-3:].upper()}"
+
+    template = f"""
+# WARNING: If you intend to restrict a user to only running the
+# sshuttle command as root, THIS CONFIGURATION IS INSECURE.
+# When a user can run sshuttle as root (with or without a password),
+# they can also run other commands as root because sshuttle itself
+# can run a command specified by the user with the --ssh-cmd option.
+
+# INSTRUCTIONS: Add this text to your sudo configuration to run
+# sshuttle without needing to enter a sudo password. To use this
+# configuration, run 'visudo /etc/sudoers.d/sshuttle_auto' as root and
+# paste this text into the editor that it opens. If you want to give
+# multiple users these privileges, you may wish to use different
+# filenames for each one (i.e., /etc/sudoers.d/sshuttle_auto_john).
+
+# This configuration was initially generated by the
+# 'sshuttle --sudoers-no-modify' command.
+
+Cmnd_Alias {cmd_alias} = /usr/bin/env PYTHONPATH={dist_packages} {executable} *
+
+{user_name} ALL=NOPASSWD: {cmd_alias}
+"""
+
+    return template
+
+
+def sudoers(user_name=None):
+    user_name = user_name or getpass.getuser()
+    content = build_config(user_name)
+    sys.stdout.write(content)
+    exit(0)

tests/client/test_firewall.py

@@ -0,0 +1,163 @@
+import io
+import os
+from socket import AF_INET, AF_INET6
+
+from unittest.mock import Mock, patch, call
+
+import pytest
+
+import sshuttle.firewall
+
+
+def setup_daemon():
+    stdin = io.BytesIO(u"""ROUTES
+{inet},24,0,1.2.3.0,8000,9000
+{inet},32,1,1.2.3.66,8080,8080
+{inet6},64,0,2404:6800:4004:80c::,0,0
+{inet6},128,1,2404:6800:4004:80c::101f,80,80
+NSLIST
+{inet},1.2.3.33
+{inet6},2404:6800:4004:80c::33
+PORTS 1024,1025,1026,1027
+GO 1 - - 0x01 12345
+HOST 1.2.3.3,existing
+""".format(inet=AF_INET, inet6=AF_INET6).encode('ASCII'))
+    stdout = Mock()
+    return stdin, stdout
+
+
+def test_rewrite_etc_hosts(tmpdir):
+    orig_hosts = tmpdir.join("hosts.orig")
+    orig_hosts.write("1.2.3.3 existing\n")
+
+    new_hosts = tmpdir.join("hosts")
+    orig_hosts.copy(new_hosts)
+
+    hostmap = {
+        'myhost': '1.2.3.4',
+        'myotherhost': '1.2.3.5',
+    }
+    with patch('sshuttle.firewall.HOSTSFILE', new=str(new_hosts)):
+        sshuttle.firewall.rewrite_etc_hosts(hostmap, 10)
+
+    with new_hosts.open() as f:
+        line = f.readline()
+        s = line.split()
+        assert s == ['1.2.3.3', 'existing']
+
+        line = f.readline()
+        s = line.split()
+        assert s == ['1.2.3.4', 'myhost',
+                     '#', 'sshuttle-firewall-10', 'AUTOCREATED']
+
+        line = f.readline()
+        s = line.split()
+        assert s == ['1.2.3.5', 'myotherhost',
+                     '#', 'sshuttle-firewall-10', 'AUTOCREATED']
+
+        line = f.readline()
+        assert line == ""
+
+    with patch('sshuttle.firewall.HOSTSFILE', new=str(new_hosts)):
+        sshuttle.firewall.restore_etc_hosts(hostmap, 10)
+    assert orig_hosts.computehash() == new_hosts.computehash()
+
+
+@patch('os.link')
+@patch('os.rename')
+def test_rewrite_etc_hosts_no_overwrite(mock_link, mock_rename, tmpdir):
+    mock_link.side_effect = OSError
+    mock_rename.side_effect = OSError
+
+    with pytest.raises(OSError):
+        os.link('/test_from', '/test_to')
+
+    with pytest.raises(OSError):
+        os.rename('/test_from', '/test_to')
+
+    test_rewrite_etc_hosts(tmpdir)
+
+
+def test_subnet_weight():
+    subnets = [
+        (AF_INET, 16, 0, '192.168.0.0', 0, 0),
+        (AF_INET, 24, 0, '192.168.69.0', 0, 0),
+        (AF_INET, 32, 0, '192.168.69.70', 0, 0),
+        (AF_INET, 32, 1, '192.168.69.70', 0, 0),
+        (AF_INET, 32, 1, '192.168.69.70', 80, 80),
+        (AF_INET, 0, 1, '0.0.0.0', 0, 0),
+        (AF_INET, 0, 1, '0.0.0.0', 8000, 9000),
+        (AF_INET, 0, 1, '0.0.0.0', 8000, 8500),
+        (AF_INET, 0, 1, '0.0.0.0', 8000, 8000),
+        (AF_INET, 0, 1, '0.0.0.0', 400, 450)
+    ]
+    subnets_sorted = [
+        (AF_INET, 32, 1, '192.168.69.70', 80, 80),
+        (AF_INET, 0, 1, '0.0.0.0', 8000, 8000),
+        (AF_INET, 0, 1, '0.0.0.0', 400, 450),
+        (AF_INET, 0, 1, '0.0.0.0', 8000, 8500),
+        (AF_INET, 0, 1, '0.0.0.0', 8000, 9000),
+        (AF_INET, 32, 1, '192.168.69.70', 0, 0),
+        (AF_INET, 32, 0, '192.168.69.70', 0, 0),
+        (AF_INET, 24, 0, '192.168.69.0', 0, 0),
+        (AF_INET, 16, 0, '192.168.0.0', 0, 0),
+        (AF_INET, 0, 1, '0.0.0.0', 0, 0)
+    ]
+
+    assert subnets_sorted == sorted(subnets,
+                                    key=sshuttle.firewall.subnet_weight,
+                                    reverse=True)
+
+
+@patch('sshuttle.firewall.rewrite_etc_hosts')
+@patch('sshuttle.firewall.setup_daemon')
+@patch('sshuttle.firewall.get_method')
+def test_main(mock_get_method, mock_setup_daemon, mock_rewrite_etc_hosts):
+    stdin, stdout = setup_daemon()
+    mock_setup_daemon.return_value = stdin, stdout
+
+    mock_get_method("not_auto").name = "test"
+    mock_get_method.reset_mock()
+
+    sshuttle.firewall.main("not_auto", False)
+
+    assert mock_rewrite_etc_hosts.mock_calls == [
+        call({'1.2.3.3': 'existing'}, 1024),
+        call({}, 1024),
+    ]
+
+    assert stdout.mock_calls == [
+        call.write(b'READY test\n'),
+        call.flush(),
+        call.write(b'STARTED\n'),
+        call.flush()
+    ]
+    assert mock_setup_daemon.mock_calls == [call()]
+    assert mock_get_method.mock_calls == [
+        call('not_auto'),
+        call().is_supported(),
+        call().is_supported().__bool__(),
+        call().setup_firewall(
+            1024, 1026,
+            [(AF_INET6, u'2404:6800:4004:80c::33')],
+            AF_INET6,
+            [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 0, 0),
+             (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 80, 80)],
+            True,
+            None,
+            None,
+            '0x01'),
+        call().setup_firewall(
+            1025, 1027,
+            [(AF_INET, u'1.2.3.33')],
+            AF_INET,
+            [(AF_INET, 24, False, u'1.2.3.0', 8000, 9000),
+             (AF_INET, 32, True, u'1.2.3.66', 8080, 8080)],
+            True,
+            None,
+            None,
+            '0x01'),
+        call().wait_for_firewall_ready(12345),
+        call().restore_firewall(1024, AF_INET6, True, None, None),
+        call().restore_firewall(1025, AF_INET, True, None, None),
+    ]

tests/client/test_helpers.py

@@ -0,0 +1,195 @@
+import io
+import socket
+from socket import AF_INET, AF_INET6
+import errno
+
+from unittest.mock import patch, call
+import sshuttle.helpers
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_log(mock_stderr, mock_stdout):
+    sshuttle.helpers.log("message")
+    sshuttle.helpers.log("abc")
+    sshuttle.helpers.log("message 1\n")
+    sshuttle.helpers.log("message 2\nline2\nline3\n")
+    sshuttle.helpers.log("message 3\nline2\nline3")
+    assert mock_stdout.mock_calls == [
+        call.flush(),
+        call.flush(),
+        call.flush(),
+        call.flush(),
+        call.flush(),
+    ]
+    assert mock_stderr.mock_calls == [
+        call.write('prefix: message\n'),
+        call.flush(),
+        call.write('prefix: abc\n'),
+        call.flush(),
+        call.write('prefix: message 1\n'),
+        call.flush(),
+        call.write('prefix: message 2\n'),
+        call.write('    line2\n'),
+        call.write('    line3\n'),
+        call.flush(),
+        call.write('prefix: message 3\n'),
+        call.write('    line2\n'),
+        call.write('    line3\n'),
+        call.flush(),
+    ]
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.verbose', new=1)
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_debug1(mock_stderr, mock_stdout):
+    sshuttle.helpers.debug1("message")
+    assert mock_stdout.mock_calls == [
+        call.flush(),
+    ]
+    assert mock_stderr.mock_calls == [
+        call.write('prefix: message\n'),
+        call.flush(),
+    ]
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.verbose', new=0)
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_debug1_nop(mock_stderr, mock_stdout):
+    sshuttle.helpers.debug1("message")
+    assert mock_stdout.mock_calls == []
+    assert mock_stderr.mock_calls == []
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.verbose', new=2)
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_debug2(mock_stderr, mock_stdout):
+    sshuttle.helpers.debug2("message")
+    assert mock_stdout.mock_calls == [
+        call.flush(),
+    ]
+    assert mock_stderr.mock_calls == [
+        call.write('prefix: message\n'),
+        call.flush(),
+    ]
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.verbose', new=1)
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_debug2_nop(mock_stderr, mock_stdout):
+    sshuttle.helpers.debug2("message")
+    assert mock_stdout.mock_calls == []
+    assert mock_stderr.mock_calls == []
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.verbose', new=3)
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_debug3(mock_stderr, mock_stdout):
+    sshuttle.helpers.debug3("message")
+    assert mock_stdout.mock_calls == [
+        call.flush(),
+    ]
+    assert mock_stderr.mock_calls == [
+        call.write('prefix: message\n'),
+        call.flush(),
+    ]
+
+
+@patch('sshuttle.helpers.logprefix', new='prefix: ')
+@patch('sshuttle.helpers.verbose', new=2)
+@patch('sshuttle.helpers.sys.stdout')
+@patch('sshuttle.helpers.sys.stderr')
+def test_debug3_nop(mock_stderr, mock_stdout):
+    sshuttle.helpers.debug3("message")
+    assert mock_stdout.mock_calls == []
+    assert mock_stderr.mock_calls == []
+
+
+@patch('sshuttle.helpers.open', create=True)
+def test_resolvconf_nameservers(mock_open):
+    mock_open.return_value = io.StringIO(u"""
+# Generated by NetworkManager
+search pri
+nameserver 192.168.1.1
+nameserver 192.168.2.1
+nameserver 192.168.3.1
+nameserver 192.168.4.1
+nameserver 2404:6800:4004:80c::1
+nameserver 2404:6800:4004:80c::2
+nameserver 2404:6800:4004:80c::3
+nameserver 2404:6800:4004:80c::4
+""")
+
+    ns = sshuttle.helpers.resolvconf_nameservers(False)
+    assert ns == [
+        (AF_INET, u'192.168.1.1'), (AF_INET, u'192.168.2.1'),
+        (AF_INET, u'192.168.3.1'), (AF_INET, u'192.168.4.1'),
+        (AF_INET6, u'2404:6800:4004:80c::1'),
+        (AF_INET6, u'2404:6800:4004:80c::2'),
+        (AF_INET6, u'2404:6800:4004:80c::3'),
+        (AF_INET6, u'2404:6800:4004:80c::4')
+    ]
+
+
+@patch('sshuttle.helpers.open', create=True)
+def test_get_random_nameserver(mock_open):
+    mock_open.return_value = io.StringIO(u"""
+# Generated by NetworkManager
+search pri
+nameserver 192.168.1.1
+nameserver 192.168.2.1
+nameserver 192.168.3.1
+nameserver 192.168.4.1
+nameserver 2404:6800:4004:80c::1
+nameserver 2404:6800:4004:80c::2
+nameserver 2404:6800:4004:80c::3
+nameserver 2404:6800:4004:80c::4
+""")
+    ns = sshuttle.helpers.get_random_nameserver()
+    assert ns in [
+        (AF_INET, u'192.168.1.1'), (AF_INET, u'192.168.2.1'),
+        (AF_INET, u'192.168.3.1'), (AF_INET, u'192.168.4.1'),
+        (AF_INET6, u'2404:6800:4004:80c::1'),
+        (AF_INET6, u'2404:6800:4004:80c::2'),
+        (AF_INET6, u'2404:6800:4004:80c::3'),
+        (AF_INET6, u'2404:6800:4004:80c::4')
+    ]
+
+
+@patch('sshuttle.helpers.socket.socket.bind')
+def test_islocal(mock_bind):
+    bind_error = socket.error(errno.EADDRNOTAVAIL)
+    mock_bind.side_effect = [None, bind_error, None, bind_error]
+
+    assert sshuttle.helpers.islocal("127.0.0.1", AF_INET)
+    assert not sshuttle.helpers.islocal("192.0.2.1", AF_INET)
+    assert sshuttle.helpers.islocal("::1", AF_INET6)
+    assert not sshuttle.helpers.islocal("2001:db8::1", AF_INET6)
+
+
+def test_family_ip_tuple():
+    assert sshuttle.helpers.family_ip_tuple("127.0.0.1") \
+        == (AF_INET, "127.0.0.1")
+    assert sshuttle.helpers.family_ip_tuple("192.168.2.6") \
+        == (AF_INET, "192.168.2.6")
+    assert sshuttle.helpers.family_ip_tuple("::1") \
+        == (AF_INET6, "::1")
+    assert sshuttle.helpers.family_ip_tuple("2404:6800:4004:80c::1") \
+        == (AF_INET6, "2404:6800:4004:80c::1")
+
+
+def test_family_to_string():
+    assert sshuttle.helpers.family_to_string(AF_INET) == "AF_INET"
+    assert sshuttle.helpers.family_to_string(AF_INET6) == "AF_INET6"
+    assert isinstance(sshuttle.helpers.family_to_string(socket.AF_UNIX), str)

tests/client/test_methods_nat.py

@@ -0,0 +1,215 @@
+import socket
+from socket import AF_INET, AF_INET6
+import struct
+
+import pytest
+from unittest.mock import Mock, patch, call
+from sshuttle.helpers import Fatal
+from sshuttle.methods import get_method
+
+
+def test_get_supported_features():
+    method = get_method('nat')
+    features = method.get_supported_features()
+    assert features.ipv6
+    assert not features.udp
+    assert features.dns
+
+
+def test_get_tcp_dstip():
+    sock = Mock()
+    sock.family = AF_INET
+    sock.getsockopt.return_value = struct.pack(
+        '!HHBBBB', socket.ntohs(AF_INET), 1024, 127, 0, 0, 1)
+    method = get_method('nat')
+    assert method.get_tcp_dstip(sock) == ('127.0.0.1', 1024)
+    assert sock.mock_calls == [call.getsockopt(0, 80, 16)]
+
+    sock = Mock()
+    sock.family = AF_INET6
+    sock.getsockopt.return_value = struct.pack(
+        '!HH4xBBBBBBBBBBBBBBBB', socket.ntohs(AF_INET6),
+        1024, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1)
+    method = get_method('nft')
+    assert method.get_tcp_dstip(sock) == ('::1', 1024)
+    assert sock.mock_calls == [call.getsockopt(41, 80, 64)]
+
+
+def test_recv_udp():
+    sock = Mock()
+    sock.recvfrom.return_value = "11111", "127.0.0.1"
+    method = get_method('nat')
+    result = method.recv_udp(sock, 1024)
+    assert sock.mock_calls == [call.recvfrom(1024)]
+    assert result == ("127.0.0.1", None, "11111")
+
+
+def test_send_udp():
+    sock = Mock()
+    method = get_method('nat')
+    method.send_udp(sock, None, "127.0.0.1", "22222")
+    assert sock.mock_calls == [call.sendto("22222", "127.0.0.1")]
+
+
+def test_setup_tcp_listener():
+    listener = Mock()
+    method = get_method('nat')
+    method.setup_tcp_listener(listener)
+    assert listener.mock_calls == []
+
+
+def test_setup_udp_listener():
+    listener = Mock()
+    method = get_method('nat')
+    method.setup_udp_listener(listener)
+    assert listener.mock_calls == []
+
+
+def test_assert_features():
+    method = get_method('nat')
+    features = method.get_supported_features()
+    method.assert_features(features)
+
+    features.udp = True
+    with pytest.raises(Fatal):
+        method.assert_features(features)
+
+    features.ipv6 = True
+    with pytest.raises(Fatal):
+        method.assert_features(features)
+
+
+def test_firewall_command():
+    method = get_method('nat')
+    assert not method.firewall_command("something")
+
+
+@patch('sshuttle.methods.nat.ipt')
+@patch('sshuttle.methods.nat.ipt_chain_exists')
+def test_setup_firewall(mock_ipt_chain_exists, mock_ipt):
+    mock_ipt_chain_exists.return_value = True
+    method = get_method('nat')
+    assert method.name == 'nat'
+
+    assert mock_ipt_chain_exists.mock_calls == []
+    assert mock_ipt.mock_calls == []
+    method.setup_firewall(
+        1024, 1026,
+        [(AF_INET6, u'2404:6800:4004:80c::33')],
+        AF_INET6,
+        [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 0, 0),
+         (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 80, 80)],
+        False,
+        None,
+        None,
+        '0x01')
+
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET6, 'nat', 'sshuttle-1024')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET6, 'nat', '-D', 'OUTPUT', '-j', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-D', 'PREROUTING', '-j', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-F', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-X', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-N', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-F', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-I', 'OUTPUT', '1', '-j', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-I', 'PREROUTING', '1', '-j', 'sshuttle-1024'),
+        call(AF_INET6, 'nat', '-A', 'sshuttle-1024', '-j', 'REDIRECT',
+             '--dest', u'2404:6800:4004:80c::33', '-p', 'udp',
+             '--dport', '53', '--to-ports', '1026'),
+        call(AF_INET6, 'nat', '-A', 'sshuttle-1024', '-j', 'RETURN',
+             '--dest', u'2404:6800:4004:80c::101f/128', '-p', 'tcp',
+             '--dport', '80:80'),
+        call(AF_INET6, 'nat', '-A', 'sshuttle-1024', '-j', 'REDIRECT',
+             '--dest', u'2404:6800:4004:80c::/64', '-p', 'tcp',
+             '--to-ports', '1024'),
+        call(AF_INET6, 'nat', '-A', 'sshuttle-1024', '-j', 'RETURN',
+             '-m', 'addrtype', '--dst-type', 'LOCAL')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()
+
+    assert mock_ipt_chain_exists.mock_calls == []
+    assert mock_ipt.mock_calls == []
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1025, 1027,
+            [(AF_INET, u'1.2.3.33')],
+            AF_INET,
+            [(AF_INET, 24, False, u'1.2.3.0', 8000, 9000),
+                (AF_INET, 32, True, u'1.2.3.66', 8080, 8080)],
+            True,
+            None,
+            None,
+            '0x01')
+    assert str(excinfo.value) == 'UDP not supported by nat method_name'
+    assert mock_ipt_chain_exists.mock_calls == []
+    assert mock_ipt.mock_calls == []
+
+    method.setup_firewall(
+        1025, 1027,
+        [(AF_INET, u'1.2.3.33')],
+        AF_INET,
+        [(AF_INET, 24, False, u'1.2.3.0', 8000, 9000),
+            (AF_INET, 32, True, u'1.2.3.66', 8080, 8080)],
+        False,
+        None,
+        None,
+        '0x01')
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET, 'nat', 'sshuttle-1025')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET, 'nat', '-D', 'OUTPUT', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-D', 'PREROUTING', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-X', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-N', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-I', 'OUTPUT', '1', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-I', 'PREROUTING', '1', '-j', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'REDIRECT',
+             '--dest', u'1.2.3.33', '-p', 'udp',
+             '--dport', '53', '--to-ports', '1027'),
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'RETURN',
+             '--dest', u'1.2.3.66/32', '-p', 'tcp', '--dport', '8080:8080'),
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'REDIRECT',
+             '--dest', u'1.2.3.0/24', '-p', 'tcp', '--dport', '8000:9000',
+             '--to-ports', '1025'),
+        call(AF_INET, 'nat', '-A', 'sshuttle-1025', '-j', 'RETURN',
+             '-m', 'addrtype', '--dst-type', 'LOCAL'),
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()
+
+    method.restore_firewall(1025, AF_INET, False, None, None)
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET, 'nat', 'sshuttle-1025')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET, 'nat', '-D', 'OUTPUT', '-j',
+             'sshuttle-1025'),
+        call(AF_INET, 'nat', '-D', 'PREROUTING', '-j',
+             'sshuttle-1025'),
+        call(AF_INET, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET, 'nat', '-X', 'sshuttle-1025')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()
+
+    method.restore_firewall(1025, AF_INET6, False, None, None)
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET6, 'nat', 'sshuttle-1025')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET6, 'nat', '-D', 'OUTPUT', '-j', 'sshuttle-1025'),
+        call(AF_INET6, 'nat', '-D', 'PREROUTING', '-j',
+             'sshuttle-1025'),
+        call(AF_INET6, 'nat', '-F', 'sshuttle-1025'),
+        call(AF_INET6, 'nat', '-X', 'sshuttle-1025')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()

tests/client/test_methods_pf.py

@@ -0,0 +1,506 @@
+import socket
+from socket import AF_INET, AF_INET6
+
+import pytest
+from unittest.mock import Mock, patch, call, ANY
+from sshuttle.methods import get_method
+from sshuttle.helpers import Fatal, get_env
+from sshuttle.methods.pf import FreeBsd, Darwin, OpenBsd
+
+
+def test_get_supported_features():
+    method = get_method('pf')
+    features = method.get_supported_features()
+    assert features.ipv6
+    assert not features.udp
+    assert features.dns
+
+
+@patch('sshuttle.helpers.verbose', new=3)
+def test_get_tcp_dstip():
+    sock = Mock()
+    sock.getpeername.return_value = ("127.0.0.1", 1024)
+    sock.getsockname.return_value = ("127.0.0.2", 1025)
+    sock.family = AF_INET
+
+    firewall = Mock()
+    firewall.pfile.readline.return_value = \
+        b"QUERY_PF_NAT_SUCCESS 127.0.0.3,1026\n"
+
+    method = get_method('pf')
+    method.set_firewall(firewall)
+    assert method.get_tcp_dstip(sock) == ('127.0.0.3', 1026)
+
+    assert sock.mock_calls == [
+        call.getpeername(),
+        call.getsockname(),
+    ]
+    assert firewall.mock_calls == [
+        call.pfile.write(b'QUERY_PF_NAT 2,6,127.0.0.1,1024,127.0.0.2,1025\n'),
+        call.pfile.flush(),
+        call.pfile.readline()
+    ]
+
+
+def test_recv_udp():
+    sock = Mock()
+    sock.recvfrom.return_value = "11111", "127.0.0.1"
+    method = get_method('pf')
+    result = method.recv_udp(sock, 1024)
+    assert sock.mock_calls == [call.recvfrom(1024)]
+    assert result == ("127.0.0.1", None, "11111")
+
+
+def test_send_udp():
+    sock = Mock()
+    method = get_method('pf')
+    method.send_udp(sock, None, "127.0.0.1", "22222")
+    assert sock.mock_calls == [call.sendto("22222", "127.0.0.1")]
+
+
+def test_setup_tcp_listener():
+    listener = Mock()
+    method = get_method('pf')
+    method.setup_tcp_listener(listener)
+    assert listener.mock_calls == []
+
+
+def test_setup_udp_listener():
+    listener = Mock()
+    method = get_method('pf')
+    method.setup_udp_listener(listener)
+    assert listener.mock_calls == []
+
+
+def test_assert_features():
+    method = get_method('pf')
+    features = method.get_supported_features()
+    method.assert_features(features)
+
+    features.udp = True
+    with pytest.raises(Fatal):
+        method.assert_features(features)
+
+    features.ipv6 = True
+    with pytest.raises(Fatal):
+        method.assert_features(features)
+
+
+@patch('sshuttle.methods.pf.pf', Darwin())
+@patch('sshuttle.methods.pf.sys.stdout')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_firewall_command_darwin(mock_pf_get_dev, mock_ioctl, mock_stdout):
+    method = get_method('pf')
+    assert not method.firewall_command("something")
+
+    command = "QUERY_PF_NAT %d,%d,%s,%d,%s,%d\n" % (
+        AF_INET, socket.IPPROTO_TCP,
+        "127.0.0.1", 1025, "127.0.0.2", 1024)
+    assert method.firewall_command(command)
+
+    assert mock_pf_get_dev.mock_calls == [call()]
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xc0544417, ANY),
+    ]
+    assert mock_stdout.mock_calls == [
+        call.write('QUERY_PF_NAT_SUCCESS 0.0.0.0,0\n'),
+        call.flush(),
+    ]
+
+
+@patch('sshuttle.methods.pf.pf', FreeBsd())
+@patch('sshuttle.methods.pf.sys.stdout')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_firewall_command_freebsd(mock_pf_get_dev, mock_ioctl, mock_stdout):
+    method = get_method('pf')
+    assert not method.firewall_command("something")
+
+    command = "QUERY_PF_NAT %d,%d,%s,%d,%s,%d\n" % (
+        AF_INET, socket.IPPROTO_TCP,
+        "127.0.0.1", 1025, "127.0.0.2", 1024)
+    assert method.firewall_command(command)
+
+    assert mock_pf_get_dev.mock_calls == [call()]
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xc04c4417, ANY),
+    ]
+    assert mock_stdout.mock_calls == [
+        call.write('QUERY_PF_NAT_SUCCESS 0.0.0.0,0\n'),
+        call.flush(),
+    ]
+
+
+@patch('sshuttle.methods.pf.pf', OpenBsd())
+@patch('sshuttle.methods.pf.sys.stdout')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_firewall_command_openbsd(mock_pf_get_dev, mock_ioctl, mock_stdout):
+    method = get_method('pf')
+    assert not method.firewall_command("something")
+
+    command = "QUERY_PF_NAT %d,%d,%s,%d,%s,%d\n" % (
+        AF_INET, socket.IPPROTO_TCP,
+        "127.0.0.1", 1025, "127.0.0.2", 1024)
+    assert method.firewall_command(command)
+
+    assert mock_pf_get_dev.mock_calls == [call()]
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xc0504417, ANY),
+    ]
+    assert mock_stdout.mock_calls == [
+        call.write('QUERY_PF_NAT_SUCCESS 0.0.0.0,0\n'),
+        call.flush(),
+    ]
+
+
+def pfctl(args, stdin=None):
+    if args == '-s Interfaces -i lo -v':
+        return (b'lo0 (skip)',)
+    if args == '-s all':
+        return (b'INFO:\nStatus: Disabled\nanother mary had a little lamb\n',
+                b'little lamb\n')
+    if args == '-E':
+        return (b'\n', b'Token : abcdefg\n')
+    return None
+
+
+@patch('sshuttle.helpers.verbose', new=3)
+@patch('sshuttle.methods.pf.pf', Darwin())
+@patch('sshuttle.methods.pf.pfctl')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_setup_firewall_darwin(mock_pf_get_dev, mock_ioctl, mock_pfctl):
+    mock_pfctl.side_effect = pfctl
+
+    method = get_method('pf')
+    assert method.name == 'pf'
+
+    # IPV6
+
+    method.setup_firewall(
+        1024, 1026,
+        [(AF_INET6, u'2404:6800:4004:80c::33')],
+        AF_INET6,
+        [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 8000, 9000),
+            (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 8080, 8080)],
+        False,
+        None,
+        None,
+        '0x01')
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xC4704433, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+        call(mock_pf_get_dev(), 0xC4704433, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+    ]
+    assert mock_pfctl.mock_calls == [
+        call('-s Interfaces -i lo -v'),
+        call('-f /dev/stdin', b'pass on lo\n'),
+        call('-s all'),
+        call('-a sshuttle6-1024 -f /dev/stdin',
+             b'table <dns_servers> {2404:6800:4004:80c::33}\n'
+             b'rdr pass on lo0 inet6 proto tcp from ! ::1 to '
+             b'2404:6800:4004:80c::/64 port 8000:9000 -> ::1 port 1024\n'
+             b'rdr pass on lo0 inet6 proto udp '
+             b'to <dns_servers> port 53 -> ::1 port 1026\n'
+             b'pass out route-to lo0 inet6 proto tcp to '
+             b'2404:6800:4004:80c::/64 port 8000:9000 keep state\n'
+             b'pass out inet6 proto tcp to '
+             b'2404:6800:4004:80c::101f/128 port 8080:8080\n'
+             b'pass out route-to lo0 inet6 proto udp '
+             b'to <dns_servers> port 53 keep state\n'),
+        call('-E'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1025, 1027,
+            [(AF_INET, u'1.2.3.33')],
+            AF_INET,
+            [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+                (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+            True,
+            None,
+            None,
+            '0x01')
+    assert str(excinfo.value) == 'UDP not supported by pf method_name'
+    assert mock_pf_get_dev.mock_calls == []
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == []
+
+    method.setup_firewall(
+        1025, 1027,
+        [(AF_INET, u'1.2.3.33')],
+        AF_INET,
+        [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+            (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+        False,
+        None,
+        None,
+        '0x01')
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xC4704433, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+        call(mock_pf_get_dev(), 0xC4704433, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+        call(mock_pf_get_dev(), 0xCC20441A, ANY),
+    ]
+    assert mock_pfctl.mock_calls == [
+        call('-s Interfaces -i lo -v'),
+        call('-f /dev/stdin', b'pass on lo\n'),
+        call('-s all'),
+        call('-a sshuttle-1025 -f /dev/stdin',
+             b'table <dns_servers> {1.2.3.33}\n'
+             b'rdr pass on lo0 inet proto tcp from ! 127.0.0.1 to 1.2.3.0/24 '
+             b'-> 127.0.0.1 port 1025\n'
+             b'rdr pass on lo0 inet proto udp '
+             b'to <dns_servers> port 53 -> 127.0.0.1 port 1027\n'
+             b'pass out route-to lo0 inet proto tcp to 1.2.3.0/24 keep state\n'
+             b'pass out inet proto tcp to 1.2.3.66/32 port 80:80\n'
+             b'pass out route-to lo0 inet proto udp '
+             b'to <dns_servers> port 53 keep state\n'),
+        call('-E'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    method.restore_firewall(1025, AF_INET, False, None, None)
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == [
+        call('-a sshuttle-1025 -F all'),
+        call("-X abcdefg"),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_pfctl.reset_mock()
+    mock_ioctl.reset_mock()
+
+
+@patch('sshuttle.helpers.verbose', new=3)
+@patch('sshuttle.methods.pf.pf', FreeBsd())
+@patch('subprocess.call')
+@patch('sshuttle.methods.pf.pfctl')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_setup_firewall_freebsd(mock_pf_get_dev, mock_ioctl, mock_pfctl,
+                                mock_subprocess_call):
+    mock_pfctl.side_effect = pfctl
+
+    method = get_method('pf')
+    assert method.name == 'pf'
+
+    method.setup_firewall(
+        1024, 1026,
+        [(AF_INET6, u'2404:6800:4004:80c::33')],
+        AF_INET6,
+        [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 8000, 9000),
+            (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 8080, 8080)],
+        False,
+        None,
+        None,
+        '0x01')
+
+    assert mock_pfctl.mock_calls == [
+        call('-s all'),
+        call('-a sshuttle6-1024 -f /dev/stdin',
+             b'table <dns_servers> {2404:6800:4004:80c::33}\n'
+             b'rdr pass on lo0 inet6 proto tcp from ! ::1 to '
+             b'2404:6800:4004:80c::/64 port 8000:9000 -> ::1 port 1024\n'
+             b'rdr pass on lo0 inet6 proto udp '
+             b'to <dns_servers> port 53 -> ::1 port 1026\n'
+             b'pass out route-to lo0 inet6 proto tcp to '
+             b'2404:6800:4004:80c::/64 port 8000:9000 keep state\n'
+             b'pass out inet6 proto tcp to '
+             b'2404:6800:4004:80c::101f/128 port 8080:8080\n'
+             b'pass out route-to lo0 inet6 proto udp '
+             b'to <dns_servers> port 53 keep state\n'),
+        call('-e'),
+    ]
+    assert call(['kldload', 'pf'], env=get_env()) in \
+        mock_subprocess_call.mock_calls
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1025, 1027,
+            [(AF_INET, u'1.2.3.33')],
+            AF_INET,
+            [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+                (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+            True,
+            None,
+            None,
+            '0x01')
+    assert str(excinfo.value) == 'UDP not supported by pf method_name'
+    assert mock_pf_get_dev.mock_calls == []
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == []
+
+    method.setup_firewall(
+        1025, 1027,
+        [(AF_INET, u'1.2.3.33')],
+        AF_INET,
+        [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+            (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+        False,
+        None,
+        None,
+        '0x01')
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xC4704433, ANY),
+        call(mock_pf_get_dev(), 0xCBE0441A, ANY),
+        call(mock_pf_get_dev(), 0xCBE0441A, ANY),
+        call(mock_pf_get_dev(), 0xC4704433, ANY),
+        call(mock_pf_get_dev(), 0xCBE0441A, ANY),
+        call(mock_pf_get_dev(), 0xCBE0441A, ANY),
+    ]
+    assert mock_pfctl.mock_calls == [
+        call('-s all'),
+        call('-a sshuttle-1025 -f /dev/stdin',
+             b'table <dns_servers> {1.2.3.33}\n'
+             b'rdr pass on lo0 inet proto tcp from ! 127.0.0.1 '
+             b'to 1.2.3.0/24 -> 127.0.0.1 port 1025\n'
+             b'rdr pass on lo0 inet proto udp '
+             b'to <dns_servers> port 53 -> 127.0.0.1 port 1027\n'
+             b'pass out route-to lo0 inet proto tcp to 1.2.3.0/24 keep state\n'
+             b'pass out inet proto tcp to 1.2.3.66/32 port 80:80\n'
+             b'pass out route-to lo0 inet proto udp '
+             b'to <dns_servers> port 53 keep state\n'),
+        call('-e'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    method.restore_firewall(1025, AF_INET, False, None, None)
+    method.restore_firewall(1024, AF_INET6, False, None, None)
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == [
+        call('-a sshuttle-1025 -F all'),
+        call('-a sshuttle6-1024 -F all'),
+        call("-d"),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_pfctl.reset_mock()
+    mock_ioctl.reset_mock()
+
+
+@patch('sshuttle.helpers.verbose', new=3)
+@patch('sshuttle.methods.pf.pf', OpenBsd())
+@patch('sshuttle.methods.pf.pfctl')
+@patch('sshuttle.methods.pf.ioctl')
+@patch('sshuttle.methods.pf.pf_get_dev')
+def test_setup_firewall_openbsd(mock_pf_get_dev, mock_ioctl, mock_pfctl):
+    mock_pfctl.side_effect = pfctl
+
+    method = get_method('pf')
+    assert method.name == 'pf'
+
+    method.setup_firewall(
+        1024, 1026,
+        [(AF_INET6, u'2404:6800:4004:80c::33')],
+        AF_INET6,
+        [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 8000, 9000),
+            (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 8080, 8080)],
+        False,
+        None,
+        None,
+        '0x01')
+
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xcd50441a, ANY),
+        call(mock_pf_get_dev(), 0xcd50441a, ANY),
+    ]
+    assert mock_pfctl.mock_calls == [
+        call('-s Interfaces -i lo -v'),
+        call('-f /dev/stdin', b'match on lo\n'),
+        call('-s all'),
+        call('-a sshuttle6-1024 -f /dev/stdin',
+             b'table <dns_servers> {2404:6800:4004:80c::33}\n'
+             b'pass in on lo0 inet6 proto tcp to 2404:6800:4004:80c::/64 '
+             b'port 8000:9000 divert-to ::1 port 1024\n'
+             b'pass in on lo0 inet6 proto udp '
+             b'to <dns_servers> port 53 rdr-to ::1 port 1026\n'
+             b'pass out inet6 proto tcp to 2404:6800:4004:80c::/64 '
+             b'port 8000:9000 route-to lo0 keep state\n'
+             b'pass out inet6 proto tcp to '
+             b'2404:6800:4004:80c::101f/128 port 8080:8080\n'
+             b'pass out inet6 proto udp to '
+             b'<dns_servers> port 53 route-to lo0 keep state\n'),
+        call('-e'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    with pytest.raises(Exception) as excinfo:
+        method.setup_firewall(
+            1025, 1027,
+            [(AF_INET, u'1.2.3.33')],
+            AF_INET,
+            [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+                (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+            True,
+            None,
+            None,
+            '0x01')
+    assert str(excinfo.value) == 'UDP not supported by pf method_name'
+    assert mock_pf_get_dev.mock_calls == []
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == []
+
+    method.setup_firewall(
+        1025, 1027,
+        [(AF_INET, u'1.2.3.33')],
+        AF_INET,
+        [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+            (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+        False,
+        None,
+        None,
+        '0x01')
+    assert mock_ioctl.mock_calls == [
+        call(mock_pf_get_dev(), 0xcd50441a, ANY),
+        call(mock_pf_get_dev(), 0xcd50441a, ANY),
+    ]
+    assert mock_pfctl.mock_calls == [
+        call('-s Interfaces -i lo -v'),
+        call('-f /dev/stdin', b'match on lo\n'),
+        call('-s all'),
+        call('-a sshuttle-1025 -f /dev/stdin',
+             b'table <dns_servers> {1.2.3.33}\n'
+             b'pass in on lo0 inet proto tcp to 1.2.3.0/24 divert-to '
+             b'127.0.0.1 port 1025\n'
+             b'pass in on lo0 inet proto udp to '
+             b'<dns_servers> port 53 rdr-to 127.0.0.1 port 1027\n'
+             b'pass out inet proto tcp to 1.2.3.0/24 route-to lo0 keep state\n'
+             b'pass out inet proto tcp to 1.2.3.66/32 port 80:80\n'
+             b'pass out inet proto udp to '
+             b'<dns_servers> port 53 route-to lo0 keep state\n'),
+        call('-e'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_ioctl.reset_mock()
+    mock_pfctl.reset_mock()
+
+    method.restore_firewall(1025, AF_INET, False, None, None)
+    method.restore_firewall(1024, AF_INET6, False, None, None)
+    assert mock_ioctl.mock_calls == []
+    assert mock_pfctl.mock_calls == [
+        call('-a sshuttle-1025 -F all'),
+        call('-a sshuttle6-1024 -F all'),
+        call('-d'),
+    ]
+    mock_pf_get_dev.reset_mock()
+    mock_pfctl.reset_mock()
+    mock_ioctl.reset_mock()

tests/client/test_methods_tproxy.py

@@ -0,0 +1,292 @@
+import socket
+from socket import AF_INET, AF_INET6
+
+from unittest.mock import Mock, patch, call
+
+from sshuttle.methods import get_method
+
+
+def test_get_supported_features():
+    method = get_method('tproxy')
+    features = method.get_supported_features()
+    assert features.ipv6
+    assert features.udp
+    assert features.dns
+
+
+def test_get_tcp_dstip():
+    sock = Mock()
+    sock.getsockname.return_value = ('127.0.0.1', 1024)
+    method = get_method('tproxy')
+    assert method.get_tcp_dstip(sock) == ('127.0.0.1', 1024)
+    assert sock.mock_calls == [call.getsockname()]
+
+
+@patch("sshuttle.methods.tproxy.recv_udp")
+def test_recv_udp(mock_recv_udp):
+    mock_recv_udp.return_value = ("127.0.0.1", "127.0.0.2", "11111")
+
+    sock = Mock()
+    method = get_method('tproxy')
+    result = method.recv_udp(sock, 1024)
+    assert sock.mock_calls == []
+    assert mock_recv_udp.mock_calls == [call(sock, 1024)]
+    assert result == ("127.0.0.1", "127.0.0.2", "11111")
+
+
+@patch("sshuttle.methods.socket.socket")
+def test_send_udp(mock_socket):
+    sock = Mock()
+    method = get_method('tproxy')
+    method.send_udp(sock, "127.0.0.2", "127.0.0.1", "2222222")
+    assert sock.mock_calls == []
+    assert mock_socket.mock_calls == [
+        call(sock.family, 2),
+        call().setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1),
+        call().setsockopt(0, 19, 1),
+        call().bind('127.0.0.2'),
+        call().sendto("2222222", '127.0.0.1'),
+        call().close()
+    ]
+
+
+def test_setup_tcp_listener():
+    listener = Mock()
+    method = get_method('tproxy')
+    method.setup_tcp_listener(listener)
+    assert listener.mock_calls == [
+        call.setsockopt(0, 19, 1)
+    ]
+
+
+def test_setup_udp_listener():
+    listener = Mock()
+    method = get_method('tproxy')
+    method.setup_udp_listener(listener)
+    assert listener.mock_calls == [
+        call.setsockopt(0, 19, 1),
+        call.v4.setsockopt(0, 20, 1),
+        call.v6.setsockopt(41, 74, 1)
+    ]
+
+
+def test_assert_features():
+    method = get_method('tproxy')
+    features = method.get_supported_features()
+    method.assert_features(features)
+
+
+def test_firewall_command():
+    method = get_method('tproxy')
+    assert not method.firewall_command("something")
+
+
+@patch('sshuttle.methods.tproxy.ipt')
+@patch('sshuttle.methods.tproxy.ipt_chain_exists')
+def test_setup_firewall(mock_ipt_chain_exists, mock_ipt):
+    mock_ipt_chain_exists.return_value = True
+    method = get_method('tproxy')
+    assert method.name == 'tproxy'
+
+    # IPV6
+
+    method.setup_firewall(
+        1024, 1026,
+        [(AF_INET6, u'2404:6800:4004:80c::33')],
+        AF_INET6,
+        [(AF_INET6, 64, False, u'2404:6800:4004:80c::', 8000, 9000),
+            (AF_INET6, 128, True, u'2404:6800:4004:80c::101f', 8080, 8080)],
+        True,
+        None,
+        None,
+        '0x01')
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET6, 'mangle', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', 'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', 'sshuttle-d-1024')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET6, 'mangle', '-D', 'OUTPUT', '-j', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', '-X', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', '-D', 'PREROUTING', '-j', 'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', '-X', 'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-d-1024'),
+        call(AF_INET6, 'mangle', '-X', 'sshuttle-d-1024'),
+        call(AF_INET6, 'mangle', '-N', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', '-N', 'sshuttle-d-1024'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-d-1024'),
+        call(AF_INET6, 'mangle', '-N', 'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', '-I', 'OUTPUT', '1', '-j', 'sshuttle-m-1024'),
+        call(AF_INET6, 'mangle', '-I', 'PREROUTING', '1', '-j',
+             'sshuttle-t-1024'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-m-1024', '-j', 'MARK',
+             '--set-mark', '0x01', '--dest', u'2404:6800:4004:80c::33/32',
+             '-m', 'udp', '-p', 'udp', '--dport', '53'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-j', 'TPROXY',
+             '--tproxy-mark', '0x01',
+             '--dest', u'2404:6800:4004:80c::33/32',
+             '-m', 'udp', '-p', 'udp', '--dport', '53', '--on-port', '1026'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-j', 'RETURN',
+             '-m', 'addrtype', '--dst-type', 'LOCAL'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-m-1024', '-j', 'RETURN',
+             '-m', 'addrtype', '--dst-type', 'LOCAL'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-d-1024', '-j', 'MARK',
+             '--set-mark', '0x01'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-d-1024', '-j', 'ACCEPT'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-m', 'socket',
+             '-j', 'sshuttle-d-1024', '-m', 'tcp', '-p', 'tcp'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-m', 'socket',
+             '-j', 'sshuttle-d-1024', '-m', 'udp', '-p', 'udp'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-m-1024', '-j', 'RETURN',
+             '--dest', u'2404:6800:4004:80c::101f/128',
+             '-m', 'tcp', '-p', 'tcp', '--dport', '8080:8080'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-j', 'RETURN',
+             '--dest', u'2404:6800:4004:80c::101f/128',
+             '-m', 'tcp', '-p', 'tcp', '--dport', '8080:8080'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-m-1024', '-j', 'RETURN',
+             '--dest', u'2404:6800:4004:80c::101f/128',
+             '-m', 'udp', '-p', 'udp', '--dport', '8080:8080'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-j', 'RETURN',
+             '--dest', u'2404:6800:4004:80c::101f/128',
+             '-m', 'udp', '-p', 'udp', '--dport', '8080:8080'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-m-1024', '-j', 'MARK',
+             '--set-mark', '0x01', '--dest', u'2404:6800:4004:80c::/64',
+             '-m', 'tcp', '-p', 'tcp', '--dport', '8000:9000'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-j', 'TPROXY',
+             '--tproxy-mark', '0x01', '--dest',
+             u'2404:6800:4004:80c::/64',
+             '-m', 'tcp', '-p', 'tcp', '--dport', '8000:9000',
+             '--on-port', '1024'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-m-1024', '-j', 'MARK',
+             '--set-mark', '0x01', '--dest', u'2404:6800:4004:80c::/64',
+             '-m', 'udp', '-p', 'udp', '--dport', '8000:9000'),
+        call(AF_INET6, 'mangle', '-A', 'sshuttle-t-1024', '-j', 'TPROXY',
+             '--tproxy-mark', '0x01', '--dest',
+             u'2404:6800:4004:80c::/64',
+             '-m', 'udp', '-p', 'udp', '--dport', '8000:9000',
+             '--on-port', '1024')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()
+
+    method.restore_firewall(1025, AF_INET6, True, None, None)
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET6, 'mangle', 'sshuttle-m-1025'),
+        call(AF_INET6, 'mangle', 'sshuttle-t-1025'),
+        call(AF_INET6, 'mangle', 'sshuttle-d-1025')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET6, 'mangle', '-D', 'OUTPUT', '-j', 'sshuttle-m-1025'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-m-1025'),
+        call(AF_INET6, 'mangle', '-X', 'sshuttle-m-1025'),
+        call(AF_INET6, 'mangle', '-D', 'PREROUTING', '-j', 'sshuttle-t-1025'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-t-1025'),
+        call(AF_INET6, 'mangle', '-X', 'sshuttle-t-1025'),
+        call(AF_INET6, 'mangle', '-F', 'sshuttle-d-1025'),
+        call(AF_INET6, 'mangle', '-X', 'sshuttle-d-1025')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()
+
+    # IPV4
+
+    method.setup_firewall(
+        1025, 1027,
+        [(AF_INET, u'1.2.3.33')],
+        AF_INET,
+        [(AF_INET, 24, False, u'1.2.3.0', 0, 0),
+            (AF_INET, 32, True, u'1.2.3.66', 80, 80)],
+        True,
+        None,
+        None,
+        '0x01')
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET, 'mangle', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', 'sshuttle-d-1025')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET, 'mangle', '-D', 'OUTPUT', '-j', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-X', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-D', 'PREROUTING', '-j', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-X', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-d-1025'),
+        call(AF_INET, 'mangle', '-X', 'sshuttle-d-1025'),
+        call(AF_INET, 'mangle', '-N', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-N', 'sshuttle-d-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-d-1025'),
+        call(AF_INET, 'mangle', '-N', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-I', 'OUTPUT', '1', '-j', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-I', 'PREROUTING', '1', '-j',
+             'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-m-1025', '-j', 'MARK',
+             '--set-mark', '0x01', '--dest', u'1.2.3.33/32',
+             '-m', 'udp', '-p', 'udp', '--dport', '53'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-j', 'TPROXY',
+             '--tproxy-mark', '0x01', '--dest', u'1.2.3.33/32',
+             '-m', 'udp', '-p', 'udp', '--dport', '53', '--on-port', '1027'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-j', 'RETURN',
+             '-m', 'addrtype', '--dst-type', 'LOCAL'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-m-1025', '-j', 'RETURN',
+             '-m', 'addrtype', '--dst-type', 'LOCAL'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-d-1025',
+             '-j', 'MARK', '--set-mark', '0x01'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-d-1025', '-j', 'ACCEPT'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-m', 'socket',
+             '-j', 'sshuttle-d-1025', '-m', 'tcp', '-p', 'tcp'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-m', 'socket',
+             '-j', 'sshuttle-d-1025', '-m', 'udp', '-p', 'udp'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-m-1025', '-j', 'RETURN',
+             '--dest', u'1.2.3.66/32', '-m', 'tcp', '-p', 'tcp',
+             '--dport', '80:80'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-j', 'RETURN',
+             '--dest', u'1.2.3.66/32', '-m', 'tcp', '-p', 'tcp',
+             '--dport', '80:80'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-m-1025', '-j', 'RETURN',
+             '--dest', u'1.2.3.66/32', '-m', 'udp', '-p', 'udp',
+             '--dport', '80:80'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-j', 'RETURN',
+             '--dest', u'1.2.3.66/32', '-m', 'udp', '-p', 'udp',
+             '--dport', '80:80'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-m-1025', '-j', 'MARK',
+             '--set-mark', '0x01', '--dest', u'1.2.3.0/24',
+             '-m', 'tcp', '-p', 'tcp'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-j', 'TPROXY',
+             '--tproxy-mark', '0x01', '--dest', u'1.2.3.0/24',
+             '-m', 'tcp', '-p', 'tcp', '--on-port', '1025'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-m-1025', '-j', 'MARK',
+             '--set-mark', '0x01', '--dest', u'1.2.3.0/24',
+             '-m', 'udp', '-p', 'udp'),
+        call(AF_INET, 'mangle', '-A', 'sshuttle-t-1025', '-j', 'TPROXY',
+             '--tproxy-mark', '0x01', '--dest', u'1.2.3.0/24',
+             '-m', 'udp', '-p', 'udp', '--on-port', '1025')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()
+
+    method.restore_firewall(1025, AF_INET, True, None, None)
+    assert mock_ipt_chain_exists.mock_calls == [
+        call(AF_INET, 'mangle', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', 'sshuttle-d-1025')
+    ]
+    assert mock_ipt.mock_calls == [
+        call(AF_INET, 'mangle', '-D', 'OUTPUT', '-j', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-X', 'sshuttle-m-1025'),
+        call(AF_INET, 'mangle', '-D', 'PREROUTING', '-j', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-X', 'sshuttle-t-1025'),
+        call(AF_INET, 'mangle', '-F', 'sshuttle-d-1025'),
+        call(AF_INET, 'mangle', '-X', 'sshuttle-d-1025')
+    ]
+    mock_ipt_chain_exists.reset_mock()
+    mock_ipt.reset_mock()

tests/client/test_options.py

@@ -0,0 +1,208 @@
+import socket
+from argparse import ArgumentTypeError as Fatal
+from unittest.mock import patch
+
+import pytest
+
+import sshuttle.options
+
+_ip4_reprs = {
+        '0.0.0.0': '0.0.0.0',
+        '255.255.255.255': '255.255.255.255',
+        '10.0': '10.0.0.0',
+        '184.172.10.74': '184.172.10.74',
+        '3098282570': '184.172.10.74',
+        '0xb8.0xac.0x0a.0x4a': '184.172.10.74',
+        '0270.0254.0012.0112': '184.172.10.74',
+}
+
+_ip4_swidths = (1, 8, 22, 27, 32)
+
+_ip6_reprs = {
+        '::': '::',
+        '::1': '::1',
+        'fc00::': 'fc00::',
+        '2a01:7e00:e000:188::1': '2a01:7e00:e000:188::1'
+}
+
+_ip6_swidths = (48, 64, 96, 115, 128)
+
+
+def _mock_getaddrinfo(host, *_):
+    return {
+        "example.com": [
+            (socket.AF_INET6, socket.SOCK_STREAM, 0, '', ('2606:2800:220:1:248:1893:25c8:1946', 0, 0, 0)),
+            (socket.AF_INET, socket.SOCK_STREAM, 0, '', ('93.184.216.34', 0)),
+        ],
+        "my.local": [
+            (socket.AF_INET6, socket.SOCK_STREAM, 0, '', ('::1', 0, 0, 0)),
+            (socket.AF_INET, socket.SOCK_STREAM, 0, '', ('127.0.0.1', 0)),
+        ],
+        "*.blogspot.com": [
+            (socket.AF_INET6, socket.SOCK_STREAM, 0, '', ('2404:6800:4004:821::2001', 0, 0, 0)),
+            (socket.AF_INET, socket.SOCK_STREAM, 0, '', ('142.251.42.129', 0)),
+        ],
+    }.get(host, [])
+
+
+def test_parse_subnetport_ip4():
+    for ip_repr, ip in _ip4_reprs.items():
+        assert sshuttle.options.parse_subnetport(ip_repr) \
+                == [(socket.AF_INET, ip, 32, 0, 0)]
+    with pytest.raises(Fatal) as excinfo:
+        sshuttle.options.parse_subnetport('10.256.0.0')
+    assert str(excinfo.value) == 'Unable to resolve address: 10.256.0.0'
+
+
+def test_parse_subnetport_ip4_with_mask():
+    for ip_repr, ip in _ip4_reprs.items():
+        for swidth in _ip4_swidths:
+            assert sshuttle.options.parse_subnetport(
+                    '/'.join((ip_repr, str(swidth)))
+                    ) == [(socket.AF_INET, ip, swidth, 0, 0)]
+    assert sshuttle.options.parse_subnetport('0/0') \
+        == [(socket.AF_INET, '0.0.0.0', 0, 0, 0)]
+    with pytest.raises(Fatal) as excinfo:
+        sshuttle.options.parse_subnetport('10.0.0.0/33')
+    assert str(excinfo.value) \
+        == 'Slash in CIDR notation (/33) is not between 0 and 32'
+
+
+def test_parse_subnetport_ip4_with_port():
+    for ip_repr, ip in _ip4_reprs.items():
+        assert sshuttle.options.parse_subnetport(':'.join((ip_repr, '80'))) \
+            == [(socket.AF_INET, ip, 32, 80, 80)]
+        assert sshuttle.options.parse_subnetport(':'.join((ip_repr, '80-90')))\
+            == [(socket.AF_INET, ip, 32, 80, 90)]
+
+
+def test_parse_subnetport_ip4_with_mask_and_port():
+    for ip_repr, ip in _ip4_reprs.items():
+        assert sshuttle.options.parse_subnetport(ip_repr + '/32:80') \
+            == [(socket.AF_INET, ip, 32, 80, 80)]
+        assert sshuttle.options.parse_subnetport(ip_repr + '/16:80-90') \
+            == [(socket.AF_INET, ip, 16, 80, 90)]
+
+
+def test_parse_subnetport_ip6():
+    for ip_repr, ip in _ip6_reprs.items():
+        assert sshuttle.options.parse_subnetport(ip_repr) \
+                == [(socket.AF_INET6, ip, 128, 0, 0)]
+
+
+def test_parse_subnetport_ip6_with_mask():
+    for ip_repr, ip in _ip6_reprs.items():
+        for swidth in _ip4_swidths + _ip6_swidths:
+            assert sshuttle.options.parse_subnetport(
+                    '/'.join((ip_repr, str(swidth)))
+                    ) == [(socket.AF_INET6, ip, swidth, 0, 0)]
+    assert sshuttle.options.parse_subnetport('::/0') \
+        == [(socket.AF_INET6, '::', 0, 0, 0)]
+    with pytest.raises(Fatal) as excinfo:
+        sshuttle.options.parse_subnetport('fc00::/129')
+    assert str(excinfo.value) \
+        == 'Slash in CIDR notation (/129) is not between 0 and 128'
+
+
+def test_parse_subnetport_ip6_with_port():
+    for ip_repr, ip in _ip6_reprs.items():
+        assert sshuttle.options.parse_subnetport('[' + ip_repr + ']:80') \
+            == [(socket.AF_INET6, ip, 128, 80, 80)]
+        assert sshuttle.options.parse_subnetport('[' + ip_repr + ']:80-90') \
+            == [(socket.AF_INET6, ip, 128, 80, 90)]
+
+
+def test_parse_subnetport_ip6_with_mask_and_port():
+    for ip_repr, ip in _ip6_reprs.items():
+        assert sshuttle.options.parse_subnetport('[' + ip_repr + '/128]:80') \
+            == [(socket.AF_INET6, ip, 128, 80, 80)]
+        assert sshuttle.options.parse_subnetport('[' + ip_repr + '/16]:80-90')\
+            == [(socket.AF_INET6, ip, 16, 80, 90)]
+
+
+def test_convert_arg_line_to_args_skips_comments():
+    parser = sshuttle.options.MyArgumentParser()
+    assert parser.convert_arg_line_to_args("# whatever something") == []
+
+
+@patch('sshuttle.options.socket.getaddrinfo', side_effect=_mock_getaddrinfo)
+def test_parse_subnetport_host(mock_getaddrinfo):
+    assert set(sshuttle.options.parse_subnetport('example.com')) \
+        == set([
+            (socket.AF_INET6, '2606:2800:220:1:248:1893:25c8:1946', 128, 0, 0),
+            (socket.AF_INET, '93.184.216.34', 32, 0, 0),
+        ])
+    assert set(sshuttle.options.parse_subnetport('my.local')) \
+        == set([
+            (socket.AF_INET6, '::1', 128, 0, 0),
+            (socket.AF_INET, '127.0.0.1', 32, 0, 0),
+        ])
+    assert set(sshuttle.options.parse_subnetport('*.blogspot.com')) \
+        == set([
+            (socket.AF_INET6, '2404:6800:4004:821::2001', 128, 0, 0),
+            (socket.AF_INET, '142.251.42.129', 32, 0, 0),
+        ])
+
+
+@patch('sshuttle.options.socket.getaddrinfo', side_effect=_mock_getaddrinfo)
+def test_parse_subnetport_host_with_port(mock_getaddrinfo):
+    assert set(sshuttle.options.parse_subnetport('example.com:80')) \
+        == set([
+            (socket.AF_INET6, '2606:2800:220:1:248:1893:25c8:1946', 128, 80, 80),
+            (socket.AF_INET, '93.184.216.34', 32, 80, 80),
+        ])
+    assert set(sshuttle.options.parse_subnetport('example.com:80-90')) \
+        == set([
+            (socket.AF_INET6, '2606:2800:220:1:248:1893:25c8:1946', 128, 80, 90),
+            (socket.AF_INET, '93.184.216.34', 32, 80, 90),
+        ])
+    assert set(sshuttle.options.parse_subnetport('my.local:445')) \
+        == set([
+            (socket.AF_INET6, '::1', 128, 445, 445),
+            (socket.AF_INET, '127.0.0.1', 32, 445, 445),
+        ])
+    assert set(sshuttle.options.parse_subnetport('my.local:445-450')) \
+        == set([
+            (socket.AF_INET6, '::1', 128, 445, 450),
+            (socket.AF_INET, '127.0.0.1', 32, 445, 450),
+        ])
+    assert set(sshuttle.options.parse_subnetport('*.blogspot.com:80')) \
+        == set([
+            (socket.AF_INET6, '2404:6800:4004:821::2001', 128, 80, 80),
+            (socket.AF_INET, '142.251.42.129', 32, 80, 80),
+        ])
+    assert set(sshuttle.options.parse_subnetport('*.blogspot.com:80-90')) \
+        == set([
+            (socket.AF_INET6, '2404:6800:4004:821::2001', 128, 80, 90),
+            (socket.AF_INET, '142.251.42.129', 32, 80, 90),
+        ])
+
+
+def test_parse_namespace():
+    valid_namespaces = [
+        'my_namespace',
+        'my.namespace',
+        'my_namespace_with_underscore',
+        'MyNamespace',
+        '@my_namespace',
+        'my.long_namespace.with.multiple.dots',
+        '@my.long_namespace.with.multiple.dots',
+        'my.Namespace.With.Mixed.Case',
+    ]
+
+    for namespace in valid_namespaces:
+        assert sshuttle.options.parse_namespace(namespace) == namespace
+
+    invalid_namespaces = [
+        '',
+        '123namespace',
+        'my-namespace',
+        'my_namespace!',
+        '.my_namespace',
+        'my_namespace.',
+        'my..namespace',
+    ]
+
+    for namespace in invalid_namespaces:
+        with pytest.raises(Fatal, match="'.*' is not a valid namespace name."):
+            sshuttle.options.parse_namespace(namespace)

tests/client/test_sdnotify.py

@@ -0,0 +1,65 @@
+import socket
+
+from unittest.mock import Mock, patch, call
+
+import sshuttle.sdnotify
+
+
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_invalid_socket_path(mock_get):
+    mock_get.return_value = 'invalid_path'
+    assert not sshuttle.sdnotify.send(sshuttle.sdnotify.ready())
+
+
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_socket_not_there(mock_get):
+    mock_get.return_value = '/run/valid_nonexistent_path'
+    assert not sshuttle.sdnotify.send(sshuttle.sdnotify.ready())
+
+
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_no_message(mock_get):
+    mock_get.return_value = '/run/valid_path'
+    assert not sshuttle.sdnotify.send()
+
+
+@patch('sshuttle.sdnotify.socket.socket')
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_socket_error(mock_get, mock_socket):
+    mock_get.return_value = '/run/valid_path'
+    mock_socket.side_effect = socket.error('test error')
+    assert not sshuttle.sdnotify.send(sshuttle.sdnotify.ready())
+
+
+@patch('sshuttle.sdnotify.socket.socket')
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify_sendto_error(mock_get, mock_socket):
+    message = sshuttle.sdnotify.ready()
+    socket_path = '/run/valid_path'
+
+    sock = Mock()
+    sock.sendto.side_effect = socket.error('test error')
+    mock_get.return_value = '/run/valid_path'
+    mock_socket.return_value = sock
+
+    assert not sshuttle.sdnotify.send(message)
+    assert sock.sendto.mock_calls == [
+        call(message, socket_path),
+    ]
+
+
+@patch('sshuttle.sdnotify.socket.socket')
+@patch('sshuttle.sdnotify.os.environ.get')
+def test_notify(mock_get, mock_socket):
+    messages = [sshuttle.sdnotify.ready(), sshuttle.sdnotify.status('Running')]
+    socket_path = '/run/valid_path'
+
+    sock = Mock()
+    sock.sendto.return_value = 1
+    mock_get.return_value = '/run/valid_path'
+    mock_socket.return_value = sock
+
+    assert sshuttle.sdnotify.send(*messages)
+    assert sock.sendto.mock_calls == [
+        call(b'\n'.join(messages), socket_path),
+    ]

tests/server/test_server.py

@@ -0,0 +1,60 @@
+import io
+import socket
+
+from unittest.mock import patch, Mock
+
+import sshuttle.server
+
+
+def test__ipmatch():
+    assert sshuttle.server._ipmatch("1.2.3.4") is not None
+    assert sshuttle.server._ipmatch("::1") is None   # ipv6 not supported
+    assert sshuttle.server._ipmatch("42 Example Street, Melbourne") is None
+
+
+def test__ipstr():
+    assert sshuttle.server._ipstr("1.2.3.4", 24) == "1.2.3.4/24"
+    assert sshuttle.server._ipstr("1.2.3.4", 32) == "1.2.3.4"
+
+
+def test__maskbits():
+    netmask = sshuttle.server._ipmatch("255.255.255.0")
+    sshuttle.server._maskbits(netmask)
+
+
+@patch('sshuttle.server.which', side_effect=lambda x: x == 'netstat')
+@patch('sshuttle.server.ssubprocess.Popen')
+def test_listroutes_netstat(mock_popen, mock_which):
+    mock_pobj = Mock()
+    mock_pobj.stdout = io.BytesIO(b"""
+Kernel IP routing table
+Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
+0.0.0.0         192.168.1.1     0.0.0.0         UG        0 0          0 wlan0
+192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 wlan0
+""")
+    mock_pobj.wait.return_value = 0
+    mock_popen.return_value = mock_pobj
+
+    routes = sshuttle.server.list_routes()
+
+    assert list(routes) == [
+        (socket.AF_INET, '192.168.1.0', 24)
+    ]
+
+
+@patch('sshuttle.server.which', side_effect=lambda x: x == 'ip')
+@patch('sshuttle.server.ssubprocess.Popen')
+def test_listroutes_iproute(mock_popen, mock_which):
+    mock_pobj = Mock()
+    mock_pobj.stdout = io.BytesIO(b"""
+default via 192.168.1.1 dev wlan0  proto static
+192.168.1.0/24 dev wlan0  proto kernel  scope link  src 192.168.1.1
+""")
+    mock_pobj.wait.return_value = 0
+    mock_popen.return_value = mock_pobj
+
+    routes = sshuttle.server.list_routes()
+
+    assert list(routes) == [
+        (socket.AF_INET, '192.168.1.0', 24)
+    ]

tests/ssh/test_parse_hostport.py

@@ -0,0 +1,20 @@
+from sshuttle.ssh import parse_hostport
+
+
+def test_host_only():
+    assert parse_hostport("host") == (None, None, None, "host")
+    assert parse_hostport("1.2.3.4") == (None, None, None, "1.2.3.4")
+    assert parse_hostport("2001::1") == (None, None, None, "2001::1")
+    assert parse_hostport("[2001::1]") == (None, None, None, "2001::1")
+
+
+def test_host_and_port():
+    assert parse_hostport("host:22") == (None, None, 22, "host")
+    assert parse_hostport("1.2.3.4:22") == (None, None, 22, "1.2.3.4")
+    assert parse_hostport("[2001::1]:22") == (None, None, 22, "2001::1")
+
+
+def test_username_and_host():
+    assert parse_hostport("user@host") == ("user", None, None, "host")
+    assert parse_hostport("user:@host") == ("user", None, None, "host")
+    assert parse_hostport("user:pass@host") == ("user", "pass", None, "host")

tox.ini

@@ -0,0 +1,22 @@
+[tox]
+downloadcache = {toxworkdir}/cache/
+envlist =
+    py38,
+    py39,
+    py310,
+
+[testenv]
+basepython =
+    py39: python3.9
+    py310: python3.10
+    py311: python3.11
+    py312: python3.12
+commands =
+    pip install -e .
+    # actual flake8 test
+    flake8 sshuttle tests
+    # flake8 complexity warnings
+    flake8 sshuttle tests --exit-zero --max-complexity=10
+    pytest
+deps =
+    -rrequirements-tests.txt