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from __future__ import annotations
import socket
import typing
from ..exceptions import LocationParseError
from .timeout import _DEFAULT_TIMEOUT, _TYPE_TIMEOUT
_TYPE_SOCKET_OPTIONS = typing.Sequence[typing.Tuple[int, int, typing.Union[int, bytes]]]
if typing.TYPE_CHECKING:
from .._base_connection import BaseHTTPConnection
def is_connection_dropped(conn: BaseHTTPConnection) -> bool: # Platform-specific
"""
Returns True if the connection is dropped and should be closed.
:param conn: :class:`urllib3.connection.HTTPConnection` object.
"""
return not conn.is_connected
# 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: tuple[str, int],
timeout: _TYPE_TIMEOUT = _DEFAULT_TIMEOUT,
source_address: tuple[str, int] | None = None,
socket_options: _TYPE_SOCKET_OPTIONS | None = None,
) -> socket.socket:
"""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:`socket.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()
try:
host.encode("idna")
except UnicodeError:
raise LocationParseError(f"'{host}', label empty or too long") from None
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 _DEFAULT_TIMEOUT:
sock.settimeout(timeout)
if source_address:
sock.bind(source_address)
sock.connect(sa)
# Break explicitly a reference cycle
err = None
return sock
except OSError as _:
err = _
if sock is not None:
sock.close()
if err is not None:
try:
raise err
finally:
# Break explicitly a reference cycle
err = None
else:
raise OSError("getaddrinfo returns an empty list")
def _set_socket_options(
sock: socket.socket, options: _TYPE_SOCKET_OPTIONS | None
) -> None:
if options is None:
return
for opt in options:
sock.setsockopt(*opt)
def allowed_gai_family() -> socket.AddressFamily:
"""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: str) -> bool:
"""Returns True if the system can bind an IPv6 address."""
sock = None
has_ipv6 = 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")