Function create_connection

src/urllib3/util/connection.py:27–90

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 *timeo

(
    address: tuple[str, int],
    timeout: _TYPE_TIMEOUT = _DEFAULT_TIMEOUT,
    source_address: tuple[str, int] | None = None,
    socket_options: _TYPE_SOCKET_OPTIONS | None = None,
)

# 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: