mirror of https://github.com/python/cpython
273 lines
11 KiB
Python
273 lines
11 KiB
Python
import contextlib
|
|
import errno
|
|
import socket
|
|
import unittest
|
|
import sys
|
|
|
|
from .. import support
|
|
from . import warnings_helper
|
|
|
|
HOST = "localhost"
|
|
HOSTv4 = "127.0.0.1"
|
|
HOSTv6 = "::1"
|
|
|
|
# WASI SDK 15.0 does not provide gethostname, stub raises OSError ENOTSUP.
|
|
has_gethostname = not support.is_wasi
|
|
|
|
|
|
def find_unused_port(family=socket.AF_INET, socktype=socket.SOCK_STREAM):
|
|
"""Returns an unused port that should be suitable for binding. This is
|
|
achieved by creating a temporary socket with the same family and type as
|
|
the 'sock' parameter (default is AF_INET, SOCK_STREAM), and binding it to
|
|
the specified host address (defaults to 0.0.0.0) with the port set to 0,
|
|
eliciting an unused ephemeral port from the OS. The temporary socket is
|
|
then closed and deleted, and the ephemeral port is returned.
|
|
|
|
Either this method or bind_port() should be used for any tests where a
|
|
server socket needs to be bound to a particular port for the duration of
|
|
the test. Which one to use depends on whether the calling code is creating
|
|
a python socket, or if an unused port needs to be provided in a constructor
|
|
or passed to an external program (i.e. the -accept argument to openssl's
|
|
s_server mode). Always prefer bind_port() over find_unused_port() where
|
|
possible. Hard coded ports should *NEVER* be used. As soon as a server
|
|
socket is bound to a hard coded port, the ability to run multiple instances
|
|
of the test simultaneously on the same host is compromised, which makes the
|
|
test a ticking time bomb in a buildbot environment. On Unix buildbots, this
|
|
may simply manifest as a failed test, which can be recovered from without
|
|
intervention in most cases, but on Windows, the entire python process can
|
|
completely and utterly wedge, requiring someone to log in to the buildbot
|
|
and manually kill the affected process.
|
|
|
|
(This is easy to reproduce on Windows, unfortunately, and can be traced to
|
|
the SO_REUSEADDR socket option having different semantics on Windows versus
|
|
Unix/Linux. On Unix, you can't have two AF_INET SOCK_STREAM sockets bind,
|
|
listen and then accept connections on identical host/ports. An EADDRINUSE
|
|
OSError will be raised at some point (depending on the platform and
|
|
the order bind and listen were called on each socket).
|
|
|
|
However, on Windows, if SO_REUSEADDR is set on the sockets, no EADDRINUSE
|
|
will ever be raised when attempting to bind two identical host/ports. When
|
|
accept() is called on each socket, the second caller's process will steal
|
|
the port from the first caller, leaving them both in an awkwardly wedged
|
|
state where they'll no longer respond to any signals or graceful kills, and
|
|
must be forcibly killed via OpenProcess()/TerminateProcess().
|
|
|
|
The solution on Windows is to use the SO_EXCLUSIVEADDRUSE socket option
|
|
instead of SO_REUSEADDR, which effectively affords the same semantics as
|
|
SO_REUSEADDR on Unix. Given the propensity of Unix developers in the Open
|
|
Source world compared to Windows ones, this is a common mistake. A quick
|
|
look over OpenSSL's 0.9.8g source shows that they use SO_REUSEADDR when
|
|
openssl.exe is called with the 's_server' option, for example. See
|
|
http://bugs.python.org/issue2550 for more info. The following site also
|
|
has a very thorough description about the implications of both REUSEADDR
|
|
and EXCLUSIVEADDRUSE on Windows:
|
|
http://msdn2.microsoft.com/en-us/library/ms740621(VS.85).aspx)
|
|
|
|
XXX: although this approach is a vast improvement on previous attempts to
|
|
elicit unused ports, it rests heavily on the assumption that the ephemeral
|
|
port returned to us by the OS won't immediately be dished back out to some
|
|
other process when we close and delete our temporary socket but before our
|
|
calling code has a chance to bind the returned port. We can deal with this
|
|
issue if/when we come across it.
|
|
"""
|
|
|
|
with socket.socket(family, socktype) as tempsock:
|
|
port = bind_port(tempsock)
|
|
del tempsock
|
|
return port
|
|
|
|
def bind_port(sock, host=HOST):
|
|
"""Bind the socket to a free port and return the port number. Relies on
|
|
ephemeral ports in order to ensure we are using an unbound port. This is
|
|
important as many tests may be running simultaneously, especially in a
|
|
buildbot environment. This method raises an exception if the sock.family
|
|
is AF_INET and sock.type is SOCK_STREAM, *and* the socket has SO_REUSEADDR
|
|
or SO_REUSEPORT set on it. Tests should *never* set these socket options
|
|
for TCP/IP sockets. The only case for setting these options is testing
|
|
multicasting via multiple UDP sockets.
|
|
|
|
Additionally, if the SO_EXCLUSIVEADDRUSE socket option is available (i.e.
|
|
on Windows), it will be set on the socket. This will prevent anyone else
|
|
from bind()'ing to our host/port for the duration of the test.
|
|
"""
|
|
|
|
if sock.family == socket.AF_INET and sock.type == socket.SOCK_STREAM:
|
|
if hasattr(socket, 'SO_REUSEADDR'):
|
|
if sock.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR) == 1:
|
|
raise support.TestFailed("tests should never set the "
|
|
"SO_REUSEADDR socket option on "
|
|
"TCP/IP sockets!")
|
|
if hasattr(socket, 'SO_REUSEPORT'):
|
|
try:
|
|
if sock.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT) == 1:
|
|
raise support.TestFailed("tests should never set the "
|
|
"SO_REUSEPORT socket option on "
|
|
"TCP/IP sockets!")
|
|
except OSError:
|
|
# Python's socket module was compiled using modern headers
|
|
# thus defining SO_REUSEPORT but this process is running
|
|
# under an older kernel that does not support SO_REUSEPORT.
|
|
pass
|
|
if hasattr(socket, 'SO_EXCLUSIVEADDRUSE'):
|
|
sock.setsockopt(socket.SOL_SOCKET, socket.SO_EXCLUSIVEADDRUSE, 1)
|
|
|
|
sock.bind((host, 0))
|
|
port = sock.getsockname()[1]
|
|
return port
|
|
|
|
def bind_unix_socket(sock, addr):
|
|
"""Bind a unix socket, raising SkipTest if PermissionError is raised."""
|
|
assert sock.family == socket.AF_UNIX
|
|
try:
|
|
sock.bind(addr)
|
|
except PermissionError:
|
|
sock.close()
|
|
raise unittest.SkipTest('cannot bind AF_UNIX sockets')
|
|
|
|
def _is_ipv6_enabled():
|
|
"""Check whether IPv6 is enabled on this host."""
|
|
if socket.has_ipv6:
|
|
sock = None
|
|
try:
|
|
sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
|
|
sock.bind((HOSTv6, 0))
|
|
return True
|
|
except OSError:
|
|
pass
|
|
finally:
|
|
if sock:
|
|
sock.close()
|
|
return False
|
|
|
|
IPV6_ENABLED = _is_ipv6_enabled()
|
|
|
|
|
|
_bind_nix_socket_error = None
|
|
def skip_unless_bind_unix_socket(test):
|
|
"""Decorator for tests requiring a functional bind() for unix sockets."""
|
|
if not hasattr(socket, 'AF_UNIX'):
|
|
return unittest.skip('No UNIX Sockets')(test)
|
|
global _bind_nix_socket_error
|
|
if _bind_nix_socket_error is None:
|
|
from .os_helper import TESTFN, unlink
|
|
path = TESTFN + "can_bind_unix_socket"
|
|
with socket.socket(socket.AF_UNIX) as sock:
|
|
try:
|
|
sock.bind(path)
|
|
_bind_nix_socket_error = False
|
|
except OSError as e:
|
|
_bind_nix_socket_error = e
|
|
finally:
|
|
unlink(path)
|
|
if _bind_nix_socket_error:
|
|
msg = 'Requires a functional unix bind(): %s' % _bind_nix_socket_error
|
|
return unittest.skip(msg)(test)
|
|
else:
|
|
return test
|
|
|
|
|
|
def get_socket_conn_refused_errs():
|
|
"""
|
|
Get the different socket error numbers ('errno') which can be received
|
|
when a connection is refused.
|
|
"""
|
|
errors = [errno.ECONNREFUSED]
|
|
if hasattr(errno, 'ENETUNREACH'):
|
|
# On Solaris, ENETUNREACH is returned sometimes instead of ECONNREFUSED
|
|
errors.append(errno.ENETUNREACH)
|
|
if hasattr(errno, 'EADDRNOTAVAIL'):
|
|
# bpo-31910: socket.create_connection() fails randomly
|
|
# with EADDRNOTAVAIL on Travis CI
|
|
errors.append(errno.EADDRNOTAVAIL)
|
|
if hasattr(errno, 'EHOSTUNREACH'):
|
|
# bpo-37583: The destination host cannot be reached
|
|
errors.append(errno.EHOSTUNREACH)
|
|
if not IPV6_ENABLED:
|
|
errors.append(errno.EAFNOSUPPORT)
|
|
return errors
|
|
|
|
|
|
_NOT_SET = object()
|
|
|
|
@contextlib.contextmanager
|
|
def transient_internet(resource_name, *, timeout=_NOT_SET, errnos=()):
|
|
"""Return a context manager that raises ResourceDenied when various issues
|
|
with the internet connection manifest themselves as exceptions."""
|
|
nntplib = warnings_helper.import_deprecated("nntplib")
|
|
import urllib.error
|
|
if timeout is _NOT_SET:
|
|
timeout = support.INTERNET_TIMEOUT
|
|
|
|
default_errnos = [
|
|
('ECONNREFUSED', 111),
|
|
('ECONNRESET', 104),
|
|
('EHOSTUNREACH', 113),
|
|
('ENETUNREACH', 101),
|
|
('ETIMEDOUT', 110),
|
|
# socket.create_connection() fails randomly with
|
|
# EADDRNOTAVAIL on Travis CI.
|
|
('EADDRNOTAVAIL', 99),
|
|
]
|
|
default_gai_errnos = [
|
|
('EAI_AGAIN', -3),
|
|
('EAI_FAIL', -4),
|
|
('EAI_NONAME', -2),
|
|
('EAI_NODATA', -5),
|
|
# Encountered when trying to resolve IPv6-only hostnames
|
|
('WSANO_DATA', 11004),
|
|
]
|
|
|
|
denied = support.ResourceDenied("Resource %r is not available" % resource_name)
|
|
captured_errnos = errnos
|
|
gai_errnos = []
|
|
if not captured_errnos:
|
|
captured_errnos = [getattr(errno, name, num)
|
|
for (name, num) in default_errnos]
|
|
gai_errnos = [getattr(socket, name, num)
|
|
for (name, num) in default_gai_errnos]
|
|
|
|
def filter_error(err):
|
|
n = getattr(err, 'errno', None)
|
|
if (isinstance(err, TimeoutError) or
|
|
(isinstance(err, socket.gaierror) and n in gai_errnos) or
|
|
(isinstance(err, urllib.error.HTTPError) and
|
|
500 <= err.code <= 599) or
|
|
(isinstance(err, urllib.error.URLError) and
|
|
(("ConnectionRefusedError" in err.reason) or
|
|
("TimeoutError" in err.reason) or
|
|
("EOFError" in err.reason))) or
|
|
n in captured_errnos):
|
|
if not support.verbose:
|
|
sys.stderr.write(denied.args[0] + "\n")
|
|
raise denied from err
|
|
|
|
old_timeout = socket.getdefaulttimeout()
|
|
try:
|
|
if timeout is not None:
|
|
socket.setdefaulttimeout(timeout)
|
|
yield
|
|
except nntplib.NNTPTemporaryError as err:
|
|
if support.verbose:
|
|
sys.stderr.write(denied.args[0] + "\n")
|
|
raise denied from err
|
|
except OSError as err:
|
|
# urllib can wrap original socket errors multiple times (!), we must
|
|
# unwrap to get at the original error.
|
|
while True:
|
|
a = err.args
|
|
if len(a) >= 1 and isinstance(a[0], OSError):
|
|
err = a[0]
|
|
# The error can also be wrapped as args[1]:
|
|
# except socket.error as msg:
|
|
# raise OSError('socket error', msg) from msg
|
|
elif len(a) >= 2 and isinstance(a[1], OSError):
|
|
err = a[1]
|
|
else:
|
|
break
|
|
filter_error(err)
|
|
raise
|
|
# XXX should we catch generic exceptions and look for their
|
|
# __cause__ or __context__?
|
|
finally:
|
|
socket.setdefaulttimeout(old_timeout)
|