77 lines
2.6 KiB
Python
77 lines
2.6 KiB
Python
# -*- test-case-name: twisted.test.test_sendmsg -*-
|
|
# Copyright (c) Twisted Matrix Laboratories.
|
|
# See LICENSE for details.
|
|
|
|
"""
|
|
sendmsg(2) and recvmsg(2) support for Python.
|
|
"""
|
|
|
|
|
|
from collections import namedtuple
|
|
from socket import CMSG_SPACE, SCM_RIGHTS, socket as Socket
|
|
from typing import List, Tuple
|
|
|
|
__all__ = ["sendmsg", "recvmsg", "getSocketFamily", "SCM_RIGHTS"]
|
|
|
|
|
|
ReceivedMessage = namedtuple("ReceivedMessage", ["data", "ancillary", "flags"])
|
|
|
|
|
|
def sendmsg(
|
|
socket: Socket,
|
|
data: bytes,
|
|
ancillary: List[Tuple[int, int, bytes]] = [],
|
|
flags: int = 0,
|
|
) -> int:
|
|
"""
|
|
Send a message on a socket.
|
|
|
|
@param socket: The socket to send the message on.
|
|
@param data: Bytes to write to the socket.
|
|
@param ancillary: Extra data to send over the socket outside of the normal
|
|
datagram or stream mechanism. By default no ancillary data is sent.
|
|
@param flags: Flags to affect how the message is sent. See the C{MSG_}
|
|
constants in the sendmsg(2) manual page. By default no flags are set.
|
|
|
|
@return: The return value of the underlying syscall, if it succeeds.
|
|
"""
|
|
return socket.sendmsg([data], ancillary, flags)
|
|
|
|
|
|
def recvmsg(
|
|
socket: Socket, maxSize: int = 8192, cmsgSize: int = 4096, flags: int = 0
|
|
) -> ReceivedMessage:
|
|
"""
|
|
Receive a message on a socket.
|
|
|
|
@param socket: The socket to receive the message on.
|
|
@param maxSize: The maximum number of bytes to receive from the socket using
|
|
the datagram or stream mechanism. The default maximum is 8192.
|
|
@param cmsgSize: The maximum number of bytes to receive from the socket
|
|
outside of the normal datagram or stream mechanism. The default maximum
|
|
is 4096.
|
|
@param flags: Flags to affect how the message is sent. See the C{MSG_}
|
|
constants in the sendmsg(2) manual page. By default no flags are set.
|
|
|
|
@return: A named 3-tuple of the bytes received using the datagram/stream
|
|
mechanism, a L{list} of L{tuple}s giving ancillary received data, and
|
|
flags as an L{int} describing the data received.
|
|
"""
|
|
# In Twisted's _sendmsg.c, the csmg_space was defined as:
|
|
# int cmsg_size = 4096;
|
|
# cmsg_space = CMSG_SPACE(cmsg_size);
|
|
# Since the default in Python 3's socket is 0, we need to define our
|
|
# own default of 4096. -hawkie
|
|
data, ancillary, flags = socket.recvmsg(maxSize, CMSG_SPACE(cmsgSize), flags)[0:3]
|
|
|
|
return ReceivedMessage(data=data, ancillary=ancillary, flags=flags)
|
|
|
|
|
|
def getSocketFamily(socket: Socket) -> int:
|
|
"""
|
|
Return the family of the given socket.
|
|
|
|
@param socket: The socket to get the family of.
|
|
"""
|
|
return socket.family
|