# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Tests for L{twisted.python.sendmsg}.
"""
import sys
import errno
import warnings
from os import devnull, pipe, read, close, pathsep
from struct import pack
from socket import SOL_SOCKET, AF_INET, AF_INET6, socket, error
try:
from socket import AF_UNIX, socketpair
except ImportError:
nonUNIXSkip = "Platform does not support AF_UNIX sockets"
else:
nonUNIXSkip = None
from twisted.internet import reactor
from twisted.internet.defer import Deferred, inlineCallbacks
from twisted.internet.error import ProcessDone
from twisted.internet.protocol import ProcessProtocol
from twisted.python.compat import _PY3, intToBytes, bytesEnviron
from twisted.python.filepath import FilePath
from twisted.python.runtime import platform
from twisted.trial.unittest import TestCase
if platform.isLinux():
from socket import MSG_DONTWAIT
dontWaitSkip = None
else:
# It would be nice to be able to test flags on more platforms, but finding
# a flag that works *at all* is somewhat challenging.
dontWaitSkip = "MSG_DONTWAIT is only known to work as intended on Linux"
try:
from twisted.python.sendmsg import sendmsg, recvmsg
from twisted.python.sendmsg import SCM_RIGHTS, getSocketFamily
except ImportError:
importSkip = "Platform doesn't support sendmsg."
else:
importSkip = None
try:
from twisted.python.sendmsg import send1msg, recv1msg
from twisted.python.sendmsg import getsockfam
except ImportError:
CModuleImportSkip = "Cannot import twisted.python.sendmsg"
else:
CModuleImportSkip = None
class _FDHolder(object):
"""
A wrapper around a FD that will remember if it has been closed or not.
"""
def __init__(self, fd):
self._fd = fd
def fileno(self):
"""
Return the fileno of this FD.
"""
return self._fd
def close(self):
"""
Close the FD. If it's already been closed, do nothing.
"""
if self._fd:
close(self._fd)
self._fd = None
def __del__(self):
"""
If C{self._fd} is unclosed, raise a warning.
"""
if self._fd:
if not _PY3:
ResourceWarning = Warning
warnings.warn("FD %s was not closed!" % (self._fd,),
ResourceWarning)
self.close()
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
self.close()
def _makePipe():
"""
Create a pipe, and return the two FDs wrapped in L{_FDHolders}.
"""
r, w = pipe()
return (_FDHolder(r), _FDHolder(w))
class ExitedWithStderr(Exception):
"""
A process exited with some stderr.
"""
def __str__(self):
"""
Dump the errors in a pretty way in the event of a subprocess traceback.
"""
result = b'\n'.join([b''] + list(self.args))
if _PY3:
result = repr(result)
return result
class StartStopProcessProtocol(ProcessProtocol):
"""
An L{IProcessProtocol} with a Deferred for events where the subprocess
starts and stops.
@ivar started: A L{Deferred} which fires with this protocol's
L{IProcessTransport} provider when it is connected to one.
@ivar stopped: A L{Deferred} which fires with the process output or a
failure if the process produces output on standard error.
@ivar output: A C{str} used to accumulate standard output.
@ivar errors: A C{str} used to accumulate standard error.
"""
def __init__(self):
self.started = Deferred()
self.stopped = Deferred()
self.output = b''
self.errors = b''
def connectionMade(self):
self.started.callback(self.transport)
def outReceived(self, data):
self.output += data
def errReceived(self, data):
self.errors += data
def processEnded(self, reason):
if reason.check(ProcessDone):
self.stopped.callback(self.output)
else:
self.stopped.errback(ExitedWithStderr(
self.errors, self.output))
def _spawn(script, outputFD):
"""
Start a script that is a peer of this test as a subprocess.
@param script: the module name of the script in this directory (no
package prefix, no '.py')
@type script: C{str}
@rtype: L{StartStopProcessProtocol}
"""
pyExe = FilePath(sys.executable).asBytesMode().path
env = bytesEnviron()
env[b"PYTHONPATH"] = FilePath(
pathsep.join(sys.path)).asBytesMode().path
sspp = StartStopProcessProtocol()
reactor.spawnProcess(
sspp, pyExe, [
pyExe,
FilePath(__file__).sibling(script + ".py").asBytesMode().path,
intToBytes(outputFD),
],
env=env,
childFDs={0: "w", 1: "r", 2: "r", outputFD: outputFD}
)
return sspp
class BadList(list):
"""
A list which cannot be iterated sometimes.
This is a C{list} subclass to get past the type check in L{send1msg}, not
as an example of how real programs might want to interact with L{send1msg}
(or anything else). A custom C{list} subclass makes it easier to trigger
certain error cases in the implementation.
@ivar iterate: A flag which indicates whether an instance of L{BadList}
will allow iteration over itself or not. If C{False}, an attempt to
iterate over the instance will raise an exception.
"""
iterate = True
def __iter__(self):
"""
Allow normal list iteration, or raise an exception.
If C{self.iterate} is C{True}, it will be flipped to C{False} and then
normal iteration will proceed. If C{self.iterate} is C{False},
L{RuntimeError} is raised instead.
"""
if self.iterate:
self.iterate = False
return super(BadList, self).__iter__()
raise RuntimeError("Something bad happened")
class WorseList(list):
"""
A list which at first gives the appearance of being iterable, but then
raises an exception.
See L{BadList} for a warning about not writing code like this.
"""
def __iter__(self):
"""
Return an iterator which will raise an exception as soon as C{next} is
called on it.
"""
class BadIterator(object):
def next(self):
raise RuntimeError("This is a really bad case.")
return BadIterator()
class CModuleSendmsgTests(TestCase):
"""
Tests for sendmsg extension module and associated file-descriptor sending
functionality.
"""
if nonUNIXSkip is not None:
skip = nonUNIXSkip
elif CModuleImportSkip is not None:
skip = CModuleImportSkip
def setUp(self):
"""
Create a pair of UNIX sockets.
"""
self.input, self.output = socketpair(AF_UNIX)
def tearDown(self):
"""
Close the sockets opened by setUp.
"""
self.input.close()
self.output.close()
def test_sendmsgBadArguments(self):
"""
The argument types accepted by L{send1msg} are:
1. C{int}
2. read-only character buffer
3. C{int}
4. sequence
The 3rd and 4th arguments are optional. If fewer than two arguments or
more than four arguments are passed, or if any of the arguments passed
are not compatible with these types, L{TypeError} is raised.
"""
# Exercise the wrong number of arguments cases
self.assertRaises(TypeError, send1msg)
self.assertRaises(TypeError, send1msg, 1)
self.assertRaises(TypeError, send1msg,
1, "hello world", 2, [], object())
# Exercise the wrong type of arguments cases
self.assertRaises(TypeError, send1msg, object(), "hello world", 2, [])
self.assertRaises(TypeError, send1msg, 1, object(), 2, [])
self.assertRaises(TypeError, send1msg, 1, "hello world", object(), [])
self.assertRaises(TypeError, send1msg, 1, "hello world", 2, object())
def test_badAncillaryIter(self):
"""
If iteration over the ancillary data list fails (at the point of the
C{__iter__} call), the exception with which it fails is propagated to
the caller of L{send1msg}.
"""
badList = BadList()
badList.append((1, 2, "hello world"))
badList.iterate = False
self.assertRaises(RuntimeError, send1msg, 1, "hello world", 2, badList)
# Hit the second iteration
badList.iterate = True
self.assertRaises(RuntimeError, send1msg, 1, "hello world", 2, badList)
def test_badAncillaryNext(self):
"""
If iteration over the ancillary data list fails (at the point of a
C{next} call), the exception with which it fails is propagated to the
caller of L{send1msg}.
"""
worseList = WorseList()
self.assertRaises(RuntimeError, send1msg,
1, "hello world", 2,worseList)
def test_sendmsgBadAncillaryItem(self):
"""
The ancillary data list contains three-tuples with element types of:
1. C{int}
2. C{int}
3. read-only character buffer
If a tuple in the ancillary data list does not elements of these types,
L{TypeError} is raised.
"""
# Exercise the wrong number of arguments cases
self.assertRaises(TypeError, send1msg, 1, "hello world", 2, [()])
self.assertRaises(TypeError, send1msg, 1, "hello world", 2, [(1,)])
self.assertRaises(TypeError, send1msg, 1, "hello world", 2, [(1, 2)])
self.assertRaises(
TypeError,
send1msg, 1, "hello world", 2, [(1, 2, "goodbye", object())])
# Exercise the wrong type of arguments cases
exc = self.assertRaises(
TypeError, send1msg, 1, "hello world", 2, [object()])
self.assertEqual(
"send1msg argument 3 expected list of tuple, "
"got list containing object",
str(exc))
self.assertRaises(
TypeError,
send1msg, 1, "hello world", 2, [(object(), 1, "goodbye")])
self.assertRaises(
TypeError,
send1msg, 1, "hello world", 2, [(1, object(), "goodbye")])
self.assertRaises(
TypeError,
send1msg, 1, "hello world", 2, [(1, 1, object())])
def test_syscallError(self):
"""
If the underlying C{sendmsg} call fails, L{send1msg} raises
L{socket.error} with its errno set to the underlying errno value.
"""
with open(devnull) as probe:
fd = probe.fileno()
exc = self.assertRaises(error, send1msg, fd, "hello, world")
self.assertEqual(exc.args[0], errno.EBADF)
def test_syscallErrorWithControlMessage(self):
"""
The behavior when the underlying C{sendmsg} call fails is the same
whether L{send1msg} is passed ancillary data or not.
"""
with open(devnull) as probe:
fd = probe.fileno()
exc = self.assertRaises(
error, send1msg, fd, "hello, world", 0, [(0, 0, "0123")])
self.assertEqual(exc.args[0], errno.EBADF)
def test_roundtrip(self):
"""
L{recv1msg} will retrieve a message sent via L{send1msg}.
"""
message = "hello, world!"
self.assertEqual(
len(message),
send1msg(self.input.fileno(), message, 0))
result = recv1msg(fd=self.output.fileno())
self.assertEqual(result, (message, 0, []))
def test_shortsend(self):
"""
L{send1msg} returns the number of bytes which it was able to send.
"""
message = "x" * 1024 * 1024
self.input.setblocking(False)
sent = send1msg(self.input.fileno(), message)
# Sanity check - make sure the amount of data we sent was less than the
# message, but not the whole message, as we should have filled the send
# buffer. This won't work if the send buffer is more than 1MB, though.
self.assertTrue(sent < len(message))
received = recv1msg(self.output.fileno(), 0, len(message))
self.assertEqual(len(received[0]), sent)
def test_roundtripEmptyAncillary(self):
"""
L{send1msg} treats an empty ancillary data list the same way it treats
receiving no argument for the ancillary parameter at all.
"""
send1msg(self.input.fileno(), "hello, world!", 0, [])
result = recv1msg(fd=self.output.fileno())
self.assertEqual(result, ("hello, world!", 0, []))
def test_flags(self):
"""
The C{flags} argument to L{send1msg} is passed on to the underlying
C{sendmsg} call, to affect it in whatever way is defined by those
flags.
"""
# Just exercise one flag with simple, well-known behavior. MSG_DONTWAIT
# makes the send a non-blocking call, even if the socket is in blocking
# mode. See also test_flags in RecvmsgTests
for i in range(1024):
try:
send1msg(self.input.fileno(), "x" * 1024, MSG_DONTWAIT)
except error as e:
self.assertEqual(e.args[0], errno.EAGAIN)
break
else:
self.fail(
"Failed to fill up the send buffer, "
"or maybe send1msg blocked for a while")
if dontWaitSkip is not None:
test_flags.skip = dontWaitSkip
def test_wrongTypeAncillary(self):
"""
L{send1msg} will show a helpful exception message when given the wrong
type of object for the 'ancillary' argument.
"""
error = self.assertRaises(TypeError,
send1msg, self.input.fileno(),
"hello, world!", 0, 4321)
self.assertEqual(str(error),
"send1msg argument 3 expected list, got int")
@inlineCallbacks
def test_sendSubProcessFD(self):
"""
Calling L{sendsmsg} with SOL_SOCKET, SCM_RIGHTS, and a platform-endian
packed file descriptor number should send that file descriptor to a
different process, where it can be retrieved by using L{recv1msg}.
"""
sspp = _spawn("cmodulepullpipe", self.output.fileno())
yield sspp.started
pipeOut, pipeIn = _makePipe()
self.addCleanup(pipeOut.close)
self.addCleanup(pipeIn.close)
with pipeIn:
send1msg(
self.input.fileno(), "blonk", 0,
[(SOL_SOCKET, SCM_RIGHTS, pack("i", pipeIn.fileno()))])
yield sspp.stopped
self.assertEqual(read(pipeOut.fileno(), 1024),
"Test fixture data: blonk.\n")
# Make sure that the pipe is actually closed now.
self.assertEqual(read(pipeOut.fileno(), 1024), "")
def test_sendmsgTwoAncillaryDoesNotSegfault(self):
"""
L{sendmsg} with two FDs in two separate ancillary entries
does not segfault.
"""
ancillary = [
(SOL_SOCKET, SCM_RIGHTS, pack("i", self.input.fileno())),
(SOL_SOCKET, SCM_RIGHTS, pack("i", self.output.fileno())),
]
try:
send1msg(self.input.fileno(), b"some data", 0, ancillary)
except error:
# Ok as long as it doesn't segfault.
pass
class CModuleRecvmsgTests(TestCase):
"""
Tests for L{recv1msg} (primarily error handling cases).
"""
if CModuleImportSkip is not None:
skip = CModuleImportSkip
def test_badArguments(self):
"""
The argument types accepted by L{recv1msg} are:
1. C{int}
2. C{int}
3. C{int}
4. C{int}
The 2nd, 3rd, and 4th arguments are optional. If fewer than one
argument or more than four arguments are passed, or if any of the
arguments passed are not compatible with these types, L{TypeError} is
raised.
"""
# Exercise the wrong number of arguments cases
self.assertRaises(TypeError, recv1msg)
self.assertRaises(TypeError, recv1msg, 1, 2, 3, 4, object())
# Exercise the wrong type of arguments cases
self.assertRaises(TypeError, recv1msg, object(), 2, 3, 4)
self.assertRaises(TypeError, recv1msg, 1, object(), 3, 4)
self.assertRaises(TypeError, recv1msg, 1, 2, object(), 4)
self.assertRaises(TypeError, recv1msg, 1, 2, 3, object())
def test_cmsgSpaceOverflow(self):
"""
L{recv1msg} raises L{OverflowError} if passed a value for the
C{cmsg_size} argument which exceeds C{SOCKLEN_MAX}.
"""
self.assertRaises(OverflowError, recv1msg, 0, 0, 0, 0x7FFFFFFF)
def test_syscallError(self):
"""
If the underlying C{recvmsg} call fails, L{recv1msg} raises
L{socket.error} with its errno set to the underlying errno value.
"""
with open(devnull) as probe:
fd = probe.fileno()
exc = self.assertRaises(error, recv1msg, fd)
self.assertEqual(exc.args[0], errno.EBADF)
def test_flags(self):
"""
The C{flags} argument to L{recv1msg} is passed on to the underlying
C{recvmsg} call, to affect it in whatever way is defined by those
flags.
"""
# See test_flags in SendmsgTests
reader, writer = socketpair(AF_UNIX)
exc = self.assertRaises(
error, recv1msg, reader.fileno(), MSG_DONTWAIT)
self.assertEqual(exc.args[0], errno.EAGAIN)
if dontWaitSkip is not None:
test_flags.skip = dontWaitSkip
class CModuleGetSocketFamilyTests(TestCase):
"""
Tests for L{getsockfam}, a helper which reveals the address family of an
arbitrary socket.
"""
if CModuleImportSkip is not None:
skip = CModuleImportSkip
def _socket(self, addressFamily):
"""
Create a new socket using the given address family and return that
socket's file descriptor. The socket will automatically be closed when
the test is torn down.
"""
s = socket(addressFamily)
self.addCleanup(s.close)
return s.fileno()
def test_badArguments(self):
"""
L{getsockfam} accepts a single C{int} argument. If it is called in
some other way, L{TypeError} is raised.
"""
self.assertRaises(TypeError, getsockfam)
self.assertRaises(TypeError, getsockfam, 1, 2)
self.assertRaises(TypeError, getsockfam, object())
def test_syscallError(self):
"""
If the underlying C{getsockname} call fails, L{getsockfam} raises
L{socket.error} with its errno set to the underlying errno value.
"""
with open(devnull) as probe:
fd = probe.fileno()
exc = self.assertRaises(error, getsockfam, fd)
self.assertEqual(errno.EBADF, exc.args[0])
def test_inet(self):
"""
When passed the file descriptor of a socket created with the C{AF_INET}
address family, L{getsockfam} returns C{AF_INET}.
"""
self.assertEqual(AF_INET, getsockfam(self._socket(AF_INET)))
def test_inet6(self):
"""
When passed the file descriptor of a socket created with the
C{AF_INET6} address family, L{getsockfam} returns C{AF_INET6}.
"""
self.assertEqual(AF_INET6, getsockfam(self._socket(AF_INET6)))
def test_unix(self):
"""
When passed the file descriptor of a socket created with the C{AF_UNIX}
address family, L{getsockfam} returns C{AF_UNIX}.
"""
self.assertEqual(AF_UNIX, getsockfam(self._socket(AF_UNIX)))
if nonUNIXSkip is not None:
test_unix.skip = nonUNIXSkip
class SendmsgTests(TestCase):
"""
Tests for the Python2/3 compatible L{sendmsg} interface.
"""
if importSkip is not None:
skip = importSkip
def setUp(self):
"""
Create a pair of UNIX sockets.
"""
self.input, self.output = socketpair(AF_UNIX)
def tearDown(self):
"""
Close the sockets opened by setUp.
"""
self.input.close()
self.output.close()
def test_syscallError(self):
"""
If the underlying C{sendmsg} call fails, L{send1msg} raises
L{socket.error} with its errno set to the underlying errno value.
"""
self.input.close()
exc = self.assertRaises(error, sendmsg, self.input, b"hello, world")
self.assertEqual(exc.args[0], errno.EBADF)
def test_syscallErrorWithControlMessage(self):
"""
The behavior when the underlying C{sendmsg} call fails is the same
whether L{sendmsg} is passed ancillary data or not.
"""
self.input.close()
exc = self.assertRaises(
error, sendmsg, self.input, b"hello, world", [(0, 0, b"0123")], 0)
self.assertEqual(exc.args[0], errno.EBADF)
def test_roundtrip(self):
"""
L{recvmsg} will retrieve a message sent via L{sendmsg}.
"""
message = b"hello, world!"
self.assertEqual(
len(message),
sendmsg(self.input, message))
result = recvmsg(self.output)
self.assertEqual(result.data, b"hello, world!")
self.assertEqual(result.flags, 0)
self.assertEqual(result.ancillary, [])
def test_shortsend(self):
"""
L{sendmsg} returns the number of bytes which it was able to send.
"""
message = b"x" * 1024 * 1024
self.input.setblocking(False)
sent = sendmsg(self.input, message)
# Sanity check - make sure the amount of data we sent was less than the
# message, but not the whole message, as we should have filled the send
# buffer. This won't work if the send buffer is more than 1MB, though.
self.assertTrue(sent < len(message))
received = recvmsg(self.output, len(message))
self.assertEqual(len(received[0]), sent)
def test_roundtripEmptyAncillary(self):
"""
L{sendmsg} treats an empty ancillary data list the same way it treats
receiving no argument for the ancillary parameter at all.
"""
sendmsg(self.input, b"hello, world!", [], 0)
result = recvmsg(self.output)
self.assertEqual(result, (b"hello, world!", [], 0))
def test_flags(self):
"""
The C{flags} argument to L{sendmsg} is passed on to the underlying
C{sendmsg} call, to affect it in whatever way is defined by those
flags.
"""
# Just exercise one flag with simple, well-known behavior. MSG_DONTWAIT
# makes the send a non-blocking call, even if the socket is in blocking
# mode. See also test_flags in RecvmsgTests
for i in range(1024):
try:
sendmsg(self.input, b"x" * 1024, flags=MSG_DONTWAIT)
except error as e:
self.assertEqual(e.args[0], errno.EAGAIN)
break
else:
self.fail(
"Failed to fill up the send buffer, "
"or maybe send1msg blocked for a while")
if dontWaitSkip is not None:
test_flags.skip = dontWaitSkip
@inlineCallbacks
def test_sendSubProcessFD(self):
"""
Calling L{sendmsg} with SOL_SOCKET, SCM_RIGHTS, and a platform-endian
packed file descriptor number should send that file descriptor to a
different process, where it can be retrieved by using L{recv1msg}.
"""
sspp = _spawn("pullpipe", self.output.fileno())
yield sspp.started
pipeOut, pipeIn = _makePipe()
self.addCleanup(pipeOut.close)
self.addCleanup(pipeIn.close)
with pipeIn:
sendmsg(
self.input, b"blonk",
[(SOL_SOCKET, SCM_RIGHTS, pack("i", pipeIn.fileno()))])
yield sspp.stopped
self.assertEqual(read(pipeOut.fileno(), 1024),
b"Test fixture data: blonk.\n")
# Make sure that the pipe is actually closed now.
self.assertEqual(read(pipeOut.fileno(), 1024), b"")
class GetSocketFamilyTests(TestCase):
"""
Tests for L{getSocketFamily}.
"""
if importSkip is not None:
skip = importSkip
def _socket(self, addressFamily):
"""
Create a new socket using the given address family and return that
socket's file descriptor. The socket will automatically be closed when
the test is torn down.
"""
s = socket(addressFamily)
self.addCleanup(s.close)
return s
def test_inet(self):
"""
When passed the file descriptor of a socket created with the C{AF_INET}
address family, L{getSocketFamily} returns C{AF_INET}.
"""
self.assertEqual(AF_INET, getSocketFamily(self._socket(AF_INET)))
def test_inet6(self):
"""
When passed the file descriptor of a socket created with the
C{AF_INET6} address family, L{getSocketFamily} returns C{AF_INET6}.
"""
self.assertEqual(AF_INET6, getSocketFamily(self._socket(AF_INET6)))
def test_unix(self):
"""
When passed the file descriptor of a socket created with the C{AF_UNIX}
address family, L{getSocketFamily} returns C{AF_UNIX}.
"""
self.assertEqual(AF_UNIX, getSocketFamily(self._socket(AF_UNIX)))
if nonUNIXSkip is not None:
test_unix.skip = nonUNIXSkip