Previously, it was possible to run sshuttle locally without using ssh
and connecting to a remote server. In this configuration, traffic was
redirected to the sshuttle server running on the localhost. However,
the firewall needed to distinguish between traffic leaving the
sshuttle server and traffic that originated from the machine that
still needed to be routed through the sshuttle server. The TTL of the
packets leaving the sshuttle server were manipulated to indicate to
the firewall what should happen. The TTL was adjusted for all packets
leaving the sshuttle server (even if it wasn't necessary because the
server and client were running on different machines).
Changing the TTL caused trouble and some machines, and
the --ttl option was added as a workaround to change how the TTL was
set for traffic leaving sshuttle. All of this added complexity to the
code for a feature (running the server on localhost) that is likely
only used for testing and rarely used by others.
This commit updates the associated documentation, but doesn't fully
fix the ipfw method since I am unable to test that.
This change will also make sshuttle fail to work if -r is used to
specify a localhost. Pull request #610 partially addresses that issue.
For example, see: #240, #490, #660, #606.
Even when --tmark was used, the iptables code always used '1' for the
mark. This patch corrects the problem.
Previously, it wasn't clear if the tmark should be supplied in
hexadecimal or as an integer. This makes it use hexadecimal, checks
that the input is hexadecimal, and updates the associated
documentation.
This patch also makes --ttl information get passed to the firewall in
a way that matches how other information gets passed. The ttl and
tmark information are passed next to each other in many places and
this patch also makes the order consistent.
In instances where a cluster pod in a local VM needs to access a server
that is sshuttle'd from the host, since the packets arriving at the host
already made a hop, their TTL is 63 and so get ignored by sshuttle.
Allowing an override of the firewall TTL rule allows the packets to go
through.
If you use the tproxy method with a large subnet (such as 0/0), then
(1) you may not receive UDP packets that sshuttle/tproxy can handle
and (2) you are unable to connect to your machine using an IP that
your computer recognizes as its own.
To resolve those issues, any traffic to an IP that the host knows is
local, does not go through the sshuttle chains.
* re-organized imports according to pep8
* fixed all remaining pep8 issues
* moved common config into setup.cfg, additionally test `tests`
* removed --select=X -- the errors selected where by default not in
flake8's --ignore list so effectively had no effect
* update .travis.yml to reflect changes in tox.ini
* make travis just use tox in order to avoid code duplaction
* replace py.test with pytest
* fixed .travis.yml
* try different pypy toxenv
* hopefully fixed testenv for pypy
* added pypy basepython, removed unused python2.6
* install dev package before testing (fixes missing coverage)
* fixed empty exception pass blocks with noqa
* Added dummy log message on empty try-except-pass blocks to make dodacy happy :(
* Replaced Exception with BaseException
Having the tests in a `tests` directory in root is the most common
approach. Also moved pytest's conftest.py into `tests` making the
fixture available for client and server tests.
