Enable pylint checks

.github/workflows/pythonpackage.yml

@@ -30,6 +30,9 @@ jobs:
     - name: Lint with flake8
       run: |
         flake8 sshuttle tests --count --show-source --statistics
+    - name: Lint with pylint
+      run: |
+        pylint sshuttle
     - name: Test with pytest
       run: |
         PYTHONPATH=$PWD pytest

.pylintrc

@@ -0,0 +1,591 @@
+[MASTER]
+
+# A comma-separated list of package or module names from where C extensions may
+# be loaded. Extensions are loading into the active Python interpreter and may
+# run arbitrary code.
+extension-pkg-whitelist=
+
+# Specify a score threshold to be exceeded before program exits with error.
+fail-under=10.0
+
+# Add files or directories to the blacklist. They should be base names, not
+# paths.
+ignore=CVS
+
+# Add files or directories matching the regex patterns to the blacklist. The
+# regex matches against base names, not paths.
+ignore-patterns=
+
+# Python code to execute, usually for sys.path manipulation such as
+# pygtk.require().
+#init-hook=
+
+# Use multiple processes to speed up Pylint. Specifying 0 will auto-detect the
+# number of processors available to use.
+jobs=1
+
+# Control the amount of potential inferred values when inferring a single
+# object. This can help the performance when dealing with large functions or
+# complex, nested conditions.
+limit-inference-results=100
+
+# List of plugins (as comma separated values of python module names) to load,
+# usually to register additional checkers.
+load-plugins=
+
+# Pickle collected data for later comparisons.
+persistent=yes
+
+# When enabled, pylint would attempt to guess common misconfiguration and emit
+# user-friendly hints instead of false-positive error messages.
+suggestion-mode=yes
+
+# Allow loading of arbitrary C extensions. Extensions are imported into the
+# active Python interpreter and may run arbitrary code.
+unsafe-load-any-extension=no
+
+
+[MESSAGES CONTROL]
+
+# Only show warnings with the listed confidence levels. Leave empty to show
+# all. Valid levels: HIGH, INFERENCE, INFERENCE_FAILURE, UNDEFINED.
+confidence=
+
+# Disable the message, report, category or checker with the given id(s). You
+# can either give multiple identifiers separated by comma (,) or put this
+# option multiple times (only on the command line, not in the configuration
+# file where it should appear only once). You can also use "--disable=all" to
+# disable everything first and then reenable specific checks. For example, if
+# you want to run only the similarities checker, you can use "--disable=all
+# --enable=similarities". If you want to run only the classes checker, but have
+# no Warning level messages displayed, use "--disable=all --enable=classes
+# --disable=W".
+disable=print-statement,
+        parameter-unpacking,
+        unpacking-in-except,
+        old-raise-syntax,
+        backtick,
+        long-suffix,
+        old-ne-operator,
+        old-octal-literal,
+        import-star-module-level,
+        non-ascii-bytes-literal,
+        raw-checker-failed,
+        bad-inline-option,
+        locally-disabled,
+        file-ignored,
+        suppressed-message,
+        useless-suppression,
+        deprecated-pragma,
+        use-symbolic-message-instead,
+        apply-builtin,
+        basestring-builtin,
+        buffer-builtin,
+        cmp-builtin,
+        coerce-builtin,
+        execfile-builtin,
+        file-builtin,
+        long-builtin,
+        raw_input-builtin,
+        reduce-builtin,
+        standarderror-builtin,
+        unicode-builtin,
+        xrange-builtin,
+        coerce-method,
+        delslice-method,
+        getslice-method,
+        setslice-method,
+        no-absolute-import,
+        old-division,
+        dict-iter-method,
+        dict-view-method,
+        next-method-called,
+        metaclass-assignment,
+        indexing-exception,
+        raising-string,
+        reload-builtin,
+        oct-method,
+        hex-method,
+        nonzero-method,
+        cmp-method,
+        input-builtin,
+        round-builtin,
+        intern-builtin,
+        unichr-builtin,
+        map-builtin-not-iterating,
+        zip-builtin-not-iterating,
+        range-builtin-not-iterating,
+        filter-builtin-not-iterating,
+        using-cmp-argument,
+        eq-without-hash,
+        div-method,
+        idiv-method,
+        rdiv-method,
+        exception-message-attribute,
+        invalid-str-codec,
+        sys-max-int,
+        bad-python3-import,
+        deprecated-string-function,
+        deprecated-str-translate-call,
+        deprecated-itertools-function,
+        deprecated-types-field,
+        next-method-defined,
+        dict-items-not-iterating,
+        dict-keys-not-iterating,
+        dict-values-not-iterating,
+        deprecated-operator-function,
+        deprecated-urllib-function,
+        xreadlines-attribute,
+        deprecated-sys-function,
+        exception-escape,
+        comprehension-escape,
+        too-many-locals,
+        too-many-branches,
+        no-else-return
+
+# Enable the message, report, category or checker with the given id(s). You can
+# either give multiple identifier separated by comma (,) or put this option
+# multiple time (only on the command line, not in the configuration file where
+# it should appear only once). See also the "--disable" option for examples.
+enable=c-extension-no-member
+
+
+[REPORTS]
+
+# Python expression which should return a score less than or equal to 10. You
+# have access to the variables 'error', 'warning', 'refactor', and 'convention'
+# which contain the number of messages in each category, as well as 'statement'
+# which is the total number of statements analyzed. This score is used by the
+# global evaluation report (RP0004).
+evaluation=10.0 - ((float(5 * error + warning + refactor + convention) / statement) * 10)
+
+# Template used to display messages. This is a python new-style format string
+# used to format the message information. See doc for all details.
+#msg-template=
+
+# Set the output format. Available formats are text, parseable, colorized, json
+# and msvs (visual studio). You can also give a reporter class, e.g.
+# mypackage.mymodule.MyReporterClass.
+output-format=text
+
+# Tells whether to display a full report or only the messages.
+reports=no
+
+# Activate the evaluation score.
+score=yes
+
+
+[REFACTORING]
+
+# Maximum number of nested blocks for function / method body
+max-nested-blocks=5
+
+# Complete name of functions that never returns. When checking for
+# inconsistent-return-statements if a never returning function is called then
+# it will be considered as an explicit return statement and no message will be
+# printed.
+never-returning-functions=sys.exit
+
+
+[VARIABLES]
+
+# List of additional names supposed to be defined in builtins. Remember that
+# you should avoid defining new builtins when possible.
+additional-builtins=
+
+# Tells whether unused global variables should be treated as a violation.
+allow-global-unused-variables=yes
+
+# List of strings which can identify a callback function by name. A callback
+# name must start or end with one of those strings.
+callbacks=cb_,
+          _cb
+
+# A regular expression matching the name of dummy variables (i.e. expected to
+# not be used).
+dummy-variables-rgx=_+$|(_[a-zA-Z0-9_]*[a-zA-Z0-9]+?$)|dummy|^ignored_|^unused_
+
+# Argument names that match this expression will be ignored. Default to name
+# with leading underscore.
+ignored-argument-names=_.*|^ignored_|^unused_
+
+# Tells whether we should check for unused import in __init__ files.
+init-import=no
+
+# List of qualified module names which can have objects that can redefine
+# builtins.
+redefining-builtins-modules=six.moves,past.builtins,future.builtins,builtins,io
+
+
+[TYPECHECK]
+
+# List of decorators that produce context managers, such as
+# contextlib.contextmanager. Add to this list to register other decorators that
+# produce valid context managers.
+contextmanager-decorators=contextlib.contextmanager
+
+# List of members which are set dynamically and missed by pylint inference
+# system, and so shouldn't trigger E1101 when accessed. Python regular
+# expressions are accepted.
+generated-members=
+
+# Tells whether missing members accessed in mixin class should be ignored. A
+# mixin class is detected if its name ends with "mixin" (case insensitive).
+ignore-mixin-members=yes
+
+# Tells whether to warn about missing members when the owner of the attribute
+# is inferred to be None.
+ignore-none=yes
+
+# This flag controls whether pylint should warn about no-member and similar
+# checks whenever an opaque object is returned when inferring. The inference
+# can return multiple potential results while evaluating a Python object, but
+# some branches might not be evaluated, which results in partial inference. In
+# that case, it might be useful to still emit no-member and other checks for
+# the rest of the inferred objects.
+ignore-on-opaque-inference=yes
+
+# List of class names for which member attributes should not be checked (useful
+# for classes with dynamically set attributes). This supports the use of
+# qualified names.
+ignored-classes=optparse.Values,thread._local,_thread._local
+
+# List of module names for which member attributes should not be checked
+# (useful for modules/projects where namespaces are manipulated during runtime
+# and thus existing member attributes cannot be deduced by static analysis). It
+# supports qualified module names, as well as Unix pattern matching.
+ignored-modules=
+
+# Show a hint with possible names when a member name was not found. The aspect
+# of finding the hint is based on edit distance.
+missing-member-hint=yes
+
+# The minimum edit distance a name should have in order to be considered a
+# similar match for a missing member name.
+missing-member-hint-distance=1
+
+# The total number of similar names that should be taken in consideration when
+# showing a hint for a missing member.
+missing-member-max-choices=1
+
+# List of decorators that change the signature of a decorated function.
+signature-mutators=
+
+
+[MISCELLANEOUS]
+
+# List of note tags to take in consideration, separated by a comma.
+notes=FIXME,
+      XXX,
+      TODO
+
+# Regular expression of note tags to take in consideration.
+#notes-rgx=
+
+
+[SPELLING]
+
+# Limits count of emitted suggestions for spelling mistakes.
+max-spelling-suggestions=4
+
+# Spelling dictionary name. Available dictionaries: none. To make it work,
+# install the python-enchant package.
+spelling-dict=
+
+# List of comma separated words that should not be checked.
+spelling-ignore-words=
+
+# A path to a file that contains the private dictionary; one word per line.
+spelling-private-dict-file=
+
+# Tells whether to store unknown words to the private dictionary (see the
+# --spelling-private-dict-file option) instead of raising a message.
+spelling-store-unknown-words=no
+
+
+[BASIC]
+
+# Naming style matching correct argument names.
+argument-naming-style=snake_case
+
+# Regular expression matching correct argument names. Overrides argument-
+# naming-style.
+argument-rgx=
+
+# Naming style matching correct attribute names.
+attr-naming-style=snake_case
+
+# Regular expression matching correct attribute names. Overrides attr-naming-
+# style.
+#attr-rgx=
+
+# Bad variable names which should always be refused, separated by a comma.
+bad-names=foo,
+          bar,
+          baz,
+          toto,
+          tutu,
+          tata
+
+# Bad variable names regexes, separated by a comma. If names match any regex,
+# they will always be refused
+bad-names-rgxs=
+
+# Naming style matching correct class attribute names.
+class-attribute-naming-style=any
+
+# Regular expression matching correct class attribute names. Overrides class-
+# attribute-naming-style.
+class-attribute-rgx=^[a-z0-9_]{1,30}$
+
+# Naming style matching correct class names.
+class-naming-style=PascalCase
+
+# Regular expression matching correct class names. Overrides class-naming-
+# style.
+#class-rgx=
+
+# Naming style matching correct constant names.
+const-naming-style=UPPER_CASE
+
+# Regular expression matching correct constant names. Overrides const-naming-
+# style.
+#const-rgx=
+
+# Minimum line length for functions/classes that require docstrings, shorter
+# ones are exempt.
+docstring-min-length=-1
+
+# Naming style matching correct function names.
+function-naming-style=snake_case
+
+# Regular expression matching correct function names. Overrides function-
+# naming-style.
+#function-rgx=
+
+# Good variable names which should always be accepted, separated by a comma.
+good-names=i,
+           j,
+           k,
+           ex,
+           Run,
+           _
+
+# Good variable names regexes, separated by a comma. If names match any regex,
+# they will always be accepted
+good-names-rgxs=
+
+# Include a hint for the correct naming format with invalid-name.
+include-naming-hint=no
+
+# Naming style matching correct inline iteration names.
+inlinevar-naming-style=any
+
+# Regular expression matching correct inline iteration names. Overrides
+# inlinevar-naming-style.
+#inlinevar-rgx=
+
+# Naming style matching correct method names.
+method-naming-style=snake_case
+
+# Regular expression matching correct method names. Overrides method-naming-
+# style.
+#method-rgx=
+
+# Naming style matching correct module names.
+module-naming-style=snake_case
+
+# Regular expression matching correct module names. Overrides module-naming-
+# style.
+#module-rgx=
+
+# Colon-delimited sets of names that determine each other's naming style when
+# the name regexes allow several styles.
+name-group=
+
+# Regular expression which should only match function or class names that do
+# not require a docstring.
+no-docstring-rgx=^_
+
+# List of decorators that produce properties, such as abc.abstractproperty. Add
+# to this list to register other decorators that produce valid properties.
+# These decorators are taken in consideration only for invalid-name.
+property-classes=abc.abstractproperty
+
+# Naming style matching correct variable names.
+variable-naming-style=snake_case
+
+# Regular expression matching correct variable names. Overrides variable-
+# naming-style.
+variable-rgx=^[a-z0-9_]{1,30}$
+
+
+[STRING]
+
+# This flag controls whether inconsistent-quotes generates a warning when the
+# character used as a quote delimiter is used inconsistently within a module.
+check-quote-consistency=no
+
+# This flag controls whether the implicit-str-concat should generate a warning
+# on implicit string concatenation in sequences defined over several lines.
+check-str-concat-over-line-jumps=no
+
+
+[SIMILARITIES]
+
+# Ignore comments when computing similarities.
+ignore-comments=yes
+
+# Ignore docstrings when computing similarities.
+ignore-docstrings=yes
+
+# Ignore imports when computing similarities.
+ignore-imports=no
+
+# Minimum lines number of a similarity.
+min-similarity-lines=4
+
+
+[LOGGING]
+
+# The type of string formatting that logging methods do. `old` means using %
+# formatting, `new` is for `{}` formatting.
+logging-format-style=old
+
+# Logging modules to check that the string format arguments are in logging
+# function parameter format.
+logging-modules=logging
+
+
+[FORMAT]
+
+# Expected format of line ending, e.g. empty (any line ending), LF or CRLF.
+expected-line-ending-format=
+
+# Regexp for a line that is allowed to be longer than the limit.
+ignore-long-lines=^\s*(# )?<?https?://\S+>?$
+
+# Number of spaces of indent required inside a hanging or continued line.
+indent-after-paren=4
+
+# String used as indentation unit. This is usually "    " (4 spaces) or "\t" (1
+# tab).
+indent-string='    '
+
+# Maximum number of characters on a single line.
+max-line-length=100
+
+# Maximum number of lines in a module.
+max-module-lines=1000
+
+# Allow the body of a class to be on the same line as the declaration if body
+# contains single statement.
+single-line-class-stmt=no
+
+# Allow the body of an if to be on the same line as the test if there is no
+# else.
+single-line-if-stmt=no
+
+
+[CLASSES]
+
+# List of method names used to declare (i.e. assign) instance attributes.
+defining-attr-methods=__init__,
+                      __new__,
+                      setUp,
+                      __post_init__
+
+# List of member names, which should be excluded from the protected access
+# warning.
+exclude-protected=_asdict,
+                  _fields,
+                  _replace,
+                  _source,
+                  _make
+
+# List of valid names for the first argument in a class method.
+valid-classmethod-first-arg=cls
+
+# List of valid names for the first argument in a metaclass class method.
+valid-metaclass-classmethod-first-arg=cls
+
+
+[DESIGN]
+
+# Maximum number of arguments for function / method.
+max-args=5
+
+# Maximum number of attributes for a class (see R0902).
+max-attributes=7
+
+# Maximum number of boolean expressions in an if statement (see R0916).
+max-bool-expr=5
+
+# Maximum number of branch for function / method body.
+max-branches=12
+
+# Maximum number of locals for function / method body.
+max-locals=15
+
+# Maximum number of parents for a class (see R0901).
+max-parents=7
+
+# Maximum number of public methods for a class (see R0904).
+max-public-methods=20
+
+# Maximum number of return / yield for function / method body.
+max-returns=6
+
+# Maximum number of statements in function / method body.
+max-statements=50
+
+# Minimum number of public methods for a class (see R0903).
+min-public-methods=2
+
+
+[IMPORTS]
+
+# List of modules that can be imported at any level, not just the top level
+# one.
+allow-any-import-level=
+
+# Allow wildcard imports from modules that define __all__.
+allow-wildcard-with-all=no
+
+# Analyse import fallback blocks. This can be used to support both Python 2 and
+# 3 compatible code, which means that the block might have code that exists
+# only in one or another interpreter, leading to false positives when analysed.
+analyse-fallback-blocks=no
+
+# Deprecated modules which should not be used, separated by a comma.
+deprecated-modules=optparse,tkinter.tix
+
+# Create a graph of external dependencies in the given file (report RP0402 must
+# not be disabled).
+ext-import-graph=
+
+# Create a graph of every (i.e. internal and external) dependencies in the
+# given file (report RP0402 must not be disabled).
+import-graph=
+
+# Create a graph of internal dependencies in the given file (report RP0402 must
+# not be disabled).
+int-import-graph=
+
+# Force import order to recognize a module as part of the standard
+# compatibility libraries.
+known-standard-library=
+
+# Force import order to recognize a module as part of a third party library.
+known-third-party=enchant
+
+# Couples of modules and preferred modules, separated by a comma.
+preferred-modules=
+
+
+[EXCEPTIONS]
+
+# Exceptions that will emit a warning when being caught. Defaults to
+# "BaseException, Exception".
+overgeneral-exceptions=BaseException,
+                       Exception

requirements-tests.txt

@@ -5,3 +5,4 @@ pytest-cov==2.10.1
 mock==2.0.0
 flake8==3.8.4
 pyflakes==2.2.0
+pylint==2.6.0

sshuttle/__init__.py

@@ -1,3 +1,6 @@
+"""
+sshuttle: where transparent proxy meets VPN meets ssh
+"""
 try:
     from sshuttle.version import version as __version__
 except ImportError:

sshuttle/client.py

@@ -1,3 +1,4 @@
+""" Sshuttle client code """
 import errno
 import re
 import signal
@@ -40,53 +41,56 @@ except AttributeError:
 _extra_fd = os.open(os.devnull, os.O_RDONLY)
 
 
-def got_signal(signum, frame):
+def got_signal(signum, _frame):
+    """ Process client signal """
     log('exiting on signal %d\n' % signum)
     sys.exit(1)
 
 
-_pidname = None
+_PID_NAME = None
 
 
 def check_daemon(pidfile):
-    global _pidname
-    _pidname = os.path.abspath(pidfile)
+    """ Check if daemon """
+    global _PID_NAME
+    _PID_NAME = os.path.abspath(pidfile)
     try:
-        oldpid = open(_pidname).read(1024)
+        oldpid = open(_PID_NAME).read(1024)
     except IOError as e:
         if e.errno == errno.ENOENT:
             return  # no pidfile, ok
         else:
-            raise Fatal("c : can't read %s: %s" % (_pidname, e))
+            raise Fatal("c : can't read %s: %s" % (_PID_NAME, e))
     if not oldpid:
-        os.unlink(_pidname)
+        os.unlink(_PID_NAME)
         return  # invalid pidfile, ok
     oldpid = int(oldpid.strip() or 0)
     if oldpid <= 0:
-        os.unlink(_pidname)
+        os.unlink(_PID_NAME)
         return  # invalid pidfile, ok
     try:
         os.kill(oldpid, 0)
     except OSError as e:
         if e.errno == errno.ESRCH:
-            os.unlink(_pidname)
+            os.unlink(_PID_NAME)
             return  # outdated pidfile, ok
         elif e.errno == errno.EPERM:
             pass
         else:
             raise
     raise Fatal("%s: sshuttle is already running (pid=%d)"
-                % (_pidname, oldpid))
+                % (_PID_NAME, oldpid))
 
 
 def daemonize():
+    """ Run code as daemon """
     if os.fork():
-        os._exit(0)
+        sys.exit(0)
     os.setsid()
     if os.fork():
-        os._exit(0)
+        sys.exit(0)
 
-    outfd = os.open(_pidname, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o666)
+    outfd = os.open(_PID_NAME, os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o666)
     try:
         os.write(outfd, b'%d\n' % os.getpid())
     finally:
@@ -104,8 +108,9 @@ def daemonize():
 
 
 def daemon_cleanup():
+    """ Clean up after daemon """
     try:
-        os.unlink(_pidname)
+        os.unlink(_PID_NAME)
     except OSError as e:
         if e.errno == errno.ENOENT:
             pass
@@ -114,6 +119,7 @@ def daemon_cleanup():
 
 
 class MultiListener:
+    """ Listen to multiple sockets """
 
     def __init__(self, kind=socket.SOCK_STREAM, proto=0):
         self.type = kind
@@ -123,14 +129,14 @@ class MultiListener:
         self.bind_called = False
 
     def setsockopt(self, level, optname, value):
-        assert(self.bind_called)
+        assert self.bind_called
         if self.v6:
             self.v6.setsockopt(level, optname, value)
         if self.v4:
             self.v4.setsockopt(level, optname, value)
 
     def add_handler(self, handlers, callback, method, mux):
-        assert(self.bind_called)
+        assert self.bind_called
         socks = []
         if self.v6:
             socks.append(self.v6)
@@ -145,7 +151,7 @@ class MultiListener:
         )
 
     def listen(self, backlog):
-        assert(self.bind_called)
+        assert self.bind_called
         if self.v6:
             self.v6.listen(backlog)
         if self.v4:
@@ -160,7 +166,7 @@ class MultiListener:
                     raise e
 
     def bind(self, address_v6, address_v4):
-        assert(not self.bind_called)
+        assert not self.bind_called
         self.bind_called = True
         if address_v6 is not None:
             self.v6 = socket.socket(socket.AF_INET6, self.type, self.proto)
@@ -174,7 +180,7 @@ class MultiListener:
             self.v4 = None
 
     def print_listening(self, what):
-        assert(self.bind_called)
+        assert self.bind_called
         if self.v6:
             listenip = self.v6.getsockname()
             debug1('%s listening on %r.\n' % (what, listenip))
@@ -186,6 +192,7 @@ class MultiListener:
 
 
 class FirewallClient:
+    """ Start firewall code """
 
     def __init__(self, method_name, sudo_pythonpath):
         self.auto_nets = []
@@ -309,8 +316,8 @@ class FirewallClient:
             raise Fatal('%r expected STARTED, got %r' % (self.argv, line))
 
     def sethostip(self, hostname, ip):
-        assert(not re.search(br'[^-\w\.]', hostname))
-        assert(not re.search(br'[^0-9.]', ip))
+        assert not re.search(br'[^-\w\.]', hostname)
+        assert not re.search(br'[^0-9.]', ip)
         self.pfile.write(b'HOST %s,%s\n' % (hostname, ip))
         self.pfile.flush()
 
@@ -326,6 +333,7 @@ udp_by_src = {}
 
 
 def expire_connections(now, mux):
+    """ Expire connections that have timed out """
     remove = []
     for chan, timeout in dnsreqs.items():
         if timeout < now:
@@ -349,6 +357,7 @@ def expire_connections(now, mux):
 
 
 def onaccept_tcp(listener, method, mux, handlers):
+    """ Accept a new TCP connection """
     global _extra_fd
     try:
         sock, srcip = listener.accept()
@@ -386,6 +395,7 @@ def onaccept_tcp(listener, method, mux, handlers):
 
 
 def udp_done(chan, data, method, sock, dstip):
+    """ Respond to UDP request """
     (src, srcport, data) = data.split(b",", 2)
     srcip = (src, int(srcport))
     debug3('doing send from %r to %r\n' % (srcip, dstip,))
@@ -393,6 +403,7 @@ def udp_done(chan, data, method, sock, dstip):
 
 
 def onaccept_udp(listener, method, mux, handlers):
+    """ Accept a new UDP request """
     now = time.time()
     t = method.recv_udp(listener, 4096)
     if t is None:
@@ -415,6 +426,7 @@ def onaccept_udp(listener, method, mux, handlers):
 
 
 def dns_done(chan, data, method, sock, srcip, dstip, mux):
+    """ Respond to a DNS request """
     debug3('dns_done: channel=%d src=%r dst=%r\n' % (chan, srcip, dstip))
     del mux.channels[chan]
     del dnsreqs[chan]
@@ -422,6 +434,7 @@ def dns_done(chan, data, method, sock, srcip, dstip, mux):
 
 
 def ondns(listener, method, mux, handlers):
+    """ Accept a new DNS request """
     now = time.time()
     t = method.recv_udp(listener, 4096)
     if t is None:
@@ -499,7 +512,7 @@ def _main(tcp_listener, udp_listener, fw, ssh_cmd, remotename,
     sys.stdout.flush()
     if daemon:
         daemonize()
-        log('daemonizing (%s).\n' % _pidname)
+        log('daemonizing (%s).\n' % _PID_NAME)
 
     def onroutes(routestr):
         if auto_nets:
@@ -581,6 +594,7 @@ def main(listenip_v6, listenip_v4,
          method_name, seed_hosts, auto_hosts, auto_nets,
          subnets_include, subnets_exclude, daemon, to_nameserver, pidfile,
          user, sudo_pythonpath):
+    """ Main client code """
 
     if not remotename:
         print("WARNING: You must specify -r/--remote to securely route "
@@ -821,7 +835,7 @@ def main(listenip_v6, listenip_v4,
                 raise e
 
     if not bound:
-        assert(last_e)
+        assert last_e
         raise last_e
     tcp_listener.listen(10)
     tcp_listener.print_listening("TCP redirector")
@@ -867,7 +881,7 @@ def main(listenip_v6, listenip_v4,
 
         dns_listener.print_listening("DNS")
         if not bound:
-            assert(last_e)
+            assert last_e
             raise last_e
     else:
         dnsport_v6 = 0

sshuttle/hostwatch.py

@@ -197,7 +197,7 @@ def _check_smb(hostname):
         check_workgroup(workgroup)
 
     if lines:
-        assert(0)
+        assert 0
 
 
 def _check_nmb(hostname, is_workgroup, is_master):

sshuttle/sdnotify.py

@@ -35,7 +35,7 @@ def _notify(message):
     assert isinstance(message, bytes)
 
     try:
-        return (sock.sendto(message, addr) > 0)
+        return sock.sendto(message, addr) > 0
     except (OSError, IOError) as e:
         debug1("Error notifying systemd: %s\n" % e)
         return False

sshuttle/server.py

@@ -304,7 +304,7 @@ def main(latency_control, auto_hosts, to_nameserver, auto_nets):
     hw.leftover = b('')
 
     def hostwatch_ready(sock):
-        assert(hw.pid)
+        assert hw.pid
         content = hw.sock.recv(4096)
         if content:
             lines = (hw.leftover + content).split(b('\n'))
@@ -379,7 +379,7 @@ def main(latency_control, auto_hosts, to_nameserver, auto_nets):
 
     while mux.ok:
         if hw.pid:
-            assert(hw.pid > 0)
+            assert hw.pid > 0
             (rpid, rv) = os.waitpid(hw.pid, os.WNOHANG)
             if rpid:
                 raise Fatal(

sshuttle/ssh.py

@@ -1,3 +1,7 @@
+"""
+Run sshuttle via remove ssh session
+"""
+
 import sys
 import os
 import re
@@ -16,23 +20,27 @@ from sshuttle.helpers import debug2, which, get_path, Fatal
 
 
 def get_module_source(name):
+    """ Get source code for module """
     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):
+def empackage(zobj, name, data=None):
+    """ Compress and package module source code """
     if not data:
         data = get_module_source(name)
-    content = z.compress(data)
-    content += z.flush(zlib.Z_SYNC_FLUSH)
+    content = zobj.compress(data)
+    content += zobj.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:
+    Parses the given rhostport variable
+
+    rhostport looks like this:
 
             [username[:password]@]host[:port]
 
@@ -85,6 +93,7 @@ def parse_hostport(rhostport):
 
 
 def connect(ssh_cmd, rhostport, python, stderr, options):
+    """ Connect to a remote server via ssh and run sshuttle """
     username, password, port, host = parse_hostport(rhostport)
     if username:
         rhost = "{}@{}".format(username, host)

sshuttle/ssnet.py

@@ -227,7 +227,7 @@ class SockWrapper:
                 return 0
 
     def write(self, buf):
-        assert(buf)
+        assert buf
         return self.uwrite(buf)
 
     def uread(self):
@@ -402,15 +402,15 @@ class Mux(Handler):
         elif cmd == CMD_EXIT:
             self.ok = False
         elif cmd == CMD_TCP_CONNECT:
-            assert(not self.channels.get(channel))
+            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))
+            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))
+            assert not self.channels.get(channel)
             if self.got_udp_open:
                 self.got_udp_open(channel, data)
         elif cmd == CMD_ROUTES:
@@ -479,8 +479,8 @@ class Mux(Handler):
             if len(self.inbuf) >= (self.want or HDR_LEN):
                 (s1, s2, channel, cmd, datalen) = \
                     struct.unpack('!ccHHH', self.inbuf[:HDR_LEN])
-                assert(s1 == b('S'))
-                assert(s2 == b('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]

sshuttle/stresstest.py

@@ -38,7 +38,7 @@ while 1:
         r = [listener] + servers + clients
     print('select(%d)' % len(r))
     r, w, x = select.select(r, [], [], 5)
-    assert(r)
+    assert r
     for i in r:
         if i == listener:
             s, addr = listener.accept()
@@ -47,7 +47,7 @@ while 1:
             b = i.recv(4096)
             print('srv <<  %r' % len(b))
             if i not in remain:
-                assert(len(b) >= 4)
+                assert len(b) >= 4
                 want = struct.unpack('I', b[:4])[0]
                 b = b[4:]
                 # i.send('y'*want)
@@ -55,13 +55,13 @@ while 1:
                 want = remain[i]
             if want < len(b):
                 print('weird wanted %d bytes, got %d: %r' % (want, len(b), b))
-                assert(want >= len(b))
+                assert want >= len(b)
             want -= len(b)
             remain[i] = want
             if not b:  # EOF
                 if want:
                     print('weird: eof but wanted %d more' % want)
-                    assert(want == 0)
+                    assert want == 0
                 i.close()
                 servers.remove(i)
                 del remain[i]
@@ -76,13 +76,13 @@ while 1:
             want = remain[i]
             if want < len(b):
                 print('weird wanted %d bytes, got %d: %r' % (want, len(b), b))
-                assert(want >= len(b))
+                assert want >= len(b)
             want -= len(b)
             remain[i] = want
             if not b:  # EOF
                 if want:
                     print('weird: eof but wanted %d more' % want)
-                    assert(want == 0)
+                    assert want == 0
                 i.close()
                 clients.remove(i)
                 del remain[i]

sshuttle/sudoers.py

@@ -1,10 +1,13 @@
+"""
+Manage sudoers file
+"""
 import os
 import sys
 import getpass
 from uuid import uuid4
 from subprocess import Popen, PIPE
-from sshuttle.helpers import log, debug1
 from distutils import spawn
+from sshuttle.helpers import log, debug1
 
 path_to_sshuttle = sys.argv[0]
 path_to_dist_packages = os.path.dirname(os.path.abspath(__file__))[:-9]
@@ -13,7 +16,7 @@ path_to_dist_packages = os.path.dirname(os.path.abspath(__file__))[:-9]
 command_alias = 'SSHUTTLE%(num)s' % {'num': uuid4().hex[-3:].upper()}
 
 # Template for the sudoers file
-template = '''
+TEMPLATE = '''
 Cmnd_Alias %(ca)s = /usr/bin/env PYTHONPATH=%(dist_packages)s %(py)s %(path)s *
 
 %(user_name)s ALL=NOPASSWD: %(ca)s
@@ -21,7 +24,8 @@ Cmnd_Alias %(ca)s = /usr/bin/env PYTHONPATH=%(dist_packages)s %(py)s %(path)s *
 
 
 def build_config(user_name):
-    content = template % {
+    """ Build sudoers config """
+    content = TEMPLATE % {
         'ca': command_alias,
         'dist_packages': path_to_dist_packages,
         'py': sys.executable,
@@ -33,6 +37,7 @@ def build_config(user_name):
 
 
 def save_config(content, file_name):
+    """ Save sudoers config """
     process = Popen([
         '/usr/bin/sudo',
         spawn.find_executable('sudoers-add'),
@@ -47,18 +52,19 @@ def save_config(content, file_name):
     if returncode:
         log('Failed updating sudoers file.\n')
         debug1(streamdata)
-        exit(returncode)
+        sys.exit(returncode)
     else:
         log('Success, sudoers file update.\n')
-        exit(0)
+        sys.exit(0)
 
 
 def sudoers(user_name=None, no_modify=None, file_name=None):
+    """ Update sudoers config """
     user_name = user_name or getpass.getuser()
     content = build_config(user_name)
 
     if no_modify:
         sys.stdout.write(content)
-        exit(0)
+        sys.exit(0)
     else:
         save_config(content, file_name)