Coverage for /usr/local/lib/python3.7/dist-packages/urllib3/util/connection.py : 77%

from __future__ import absolute_import 

import socket 

from .wait import NoWayToWaitForSocketError, wait_for_read 

from ..contrib import _appengine_environ 

def is_connection_dropped(conn): # Platform-specific 

""" 

Returns True if the connection is dropped and should be closed. 

:param conn: 

:class:`httplib.HTTPConnection` object. 

Note: For platforms like AppEngine, this will always return ``False`` to 

let the platform handle connection recycling transparently for us. 

""" 

sock = getattr(conn, "sock", False) 

if sock is False: # Platform-specific: AppEngine 

return False 

if sock is None: # Connection already closed (such as by httplib). 

return True 

try: 

# Returns True if readable, which here means it's been dropped 

return wait_for_read(sock, timeout=0.0) 

except NoWayToWaitForSocketError: # Platform-specific: AppEngine 

return False 

# This function is copied from socket.py in the Python 2.7 standard 

# library test suite. Added to its signature is only `socket_options`. 

# One additional modification is that we avoid binding to IPv6 servers 

# discovered in DNS if the system doesn't have IPv6 functionality. 

def create_connection( 

address, 

timeout=socket._GLOBAL_DEFAULT_TIMEOUT, 

source_address=None, 

socket_options=None, 

): 

"""Connect to *address* and return the socket object. 

Convenience function. Connect to *address* (a 2-tuple ``(host, 

port)``) and return the socket object. Passing the optional 

*timeout* parameter will set the timeout on the socket instance 

before attempting to connect. If no *timeout* is supplied, the 

global default timeout setting returned by :func:`getdefaulttimeout` 

is used. If *source_address* is set it must be a tuple of (host, port) 

for the socket to bind as a source address before making the connection. 

An host of '' or port 0 tells the OS to use the default. 

""" 

host, port = address 

if host.startswith("["): 

host = host.strip("[]") 

err = None 

# Using the value from allowed_gai_family() in the context of getaddrinfo lets 

# us select whether to work with IPv4 DNS records, IPv6 records, or both. 

# The original create_connection function always returns all records. 

family = allowed_gai_family() 

for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM): 

af, socktype, proto, canonname, sa = res 

sock = None 

try: 

sock = socket.socket(af, socktype, proto) 

# If provided, set socket level options before connecting. 

_set_socket_options(sock, socket_options) 

if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT: 

sock.settimeout(timeout) 

if source_address: 

sock.bind(source_address) 

sock.connect(sa) 

return sock 

except socket.error as e: 

err = e 

if sock is not None: 

sock.close() 

sock = None 

if err is not None: 

raise err 

raise socket.error("getaddrinfo returns an empty list") 

def _set_socket_options(sock, options): 

if options is None: 

return 

for opt in options: 

sock.setsockopt(*opt) 

def allowed_gai_family(): 

"""This function is designed to work in the context of 

getaddrinfo, where family=socket.AF_UNSPEC is the default and 

will perform a DNS search for both IPv6 and IPv4 records.""" 

family = socket.AF_INET 

if HAS_IPV6: 

family = socket.AF_UNSPEC 

return family 

def _has_ipv6(host): 

""" Returns True if the system can bind an IPv6 address. """ 

sock = None 

has_ipv6 = False 

# App Engine doesn't support IPV6 sockets and actually has a quota on the 

# number of sockets that can be used, so just early out here instead of 

# creating a socket needlessly. 

# See https://github.com/urllib3/urllib3/issues/1446 

if _appengine_environ.is_appengine_sandbox(): 

return False 

if socket.has_ipv6: 

# has_ipv6 returns true if cPython was compiled with IPv6 support. 

# It does not tell us if the system has IPv6 support enabled. To 

# determine that we must bind to an IPv6 address. 

# https://github.com/urllib3/urllib3/pull/611 

# https://bugs.python.org/issue658327 

try: 

sock = socket.socket(socket.AF_INET6) 

sock.bind((host, 0)) 

has_ipv6 = True 

except Exception: 

pass 

if sock: 

sock.close() 

return has_ipv6 

HAS_IPV6 = _has_ipv6("::1")