107 lines
3.3 KiB
Python
107 lines
3.3 KiB
Python
# -*- test-case-name: twisted.test.test_sendmsg -*-
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# Copyright (c) Twisted Matrix Laboratories.
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# See LICENSE for details.
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"""
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sendmsg(2) and recvmsg(2) support for Python.
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"""
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from __future__ import absolute_import, division
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from collections import namedtuple
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from twisted.python.compat import _PY3
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__all__ = ["sendmsg", "recvmsg", "getSocketFamily", "SCM_RIGHTS"]
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if not _PY3:
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from twisted.python._sendmsg import send1msg, recv1msg
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from twisted.python._sendmsg import getsockfam, SCM_RIGHTS
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__all__ += ["send1msg", "recv1msg", "getsockfam"]
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else:
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from socket import SCM_RIGHTS, CMSG_SPACE
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RecievedMessage = namedtuple('RecievedMessage', ['data', 'ancillary', 'flags'])
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def sendmsg(socket, data, ancillary=[], flags=0):
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"""
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Send a message on a socket.
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@param socket: The socket to send the message on.
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@type socket: L{socket.socket}
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@param data: Bytes to write to the socket.
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@type data: bytes
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@param ancillary: Extra data to send over the socket outside of the normal
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datagram or stream mechanism. By default no ancillary data is sent.
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@type ancillary: C{list} of C{tuple} of C{int}, C{int}, and C{bytes}.
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@param flags: Flags to affect how the message is sent. See the C{MSG_}
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constants in the sendmsg(2) manual page. By default no flags are set.
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@type flags: C{int}
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@return: The return value of the underlying syscall, if it succeeds.
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"""
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if _PY3:
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return socket.sendmsg([data], ancillary, flags)
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else:
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return send1msg(socket.fileno(), data, flags, ancillary)
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def recvmsg(socket, maxSize=8192, cmsgSize=4096, flags=0):
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"""
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Receive a message on a socket.
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@param socket: The socket to receive the message on.
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@type socket: L{socket.socket}
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@param maxSize: The maximum number of bytes to receive from the socket using
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the datagram or stream mechanism. The default maximum is 8192.
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@type maxSize: L{int}
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@param cmsgSize: The maximum number of bytes to receive from the socket
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outside of the normal datagram or stream mechanism. The default maximum
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is 4096.
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@type cmsgSize: L{int}
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@param flags: Flags to affect how the message is sent. See the C{MSG_}
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constants in the sendmsg(2) manual page. By default no flags are set.
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@type flags: L{int}
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@return: A named 3-tuple of the bytes received using the datagram/stream
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mechanism, a L{list} of L{tuple}s giving ancillary received data, and
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flags as an L{int} describing the data received.
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"""
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if _PY3:
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# In Twisted's sendmsg.c, the csmg_space is defined as:
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# int cmsg_size = 4096;
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# cmsg_space = CMSG_SPACE(cmsg_size);
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# Since the default in Python 3's socket is 0, we need to define our
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# own default of 4096. -hawkie
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data, ancillary, flags = socket.recvmsg(
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maxSize, CMSG_SPACE(cmsgSize), flags)[0:3]
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else:
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data, flags, ancillary = recv1msg(
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socket.fileno(), flags, maxSize, cmsgSize)
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return RecievedMessage(data=data, ancillary=ancillary, flags=flags)
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def getSocketFamily(socket):
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"""
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Return the family of the given socket.
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@param socket: The socket to get the family of.
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@type socket: L{socket.socket}
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@rtype: L{int}
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"""
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if _PY3:
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return socket.family
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else:
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return getsockfam(socket.fileno())
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