# passfd.m4 serial 8

dnl Copyright (C) 2011-2018 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_PASSFD],

[

  AC_REQUIRE([gl_HEADER_SYS_SOCKET])

  AC_CHECK_FUNCS_ONCE([recvmsg sendmsg])

  dnl Persuade AIX 5.2 <sys/socket.h> to declare CMSG_SPACE, CMSG_LEN.

  dnl CMSG_FIRSTHDR is POSIX 2008, but CMSG_SPACE is only in RFC 3542.

  AC_DEFINE([_LINUX_SOURCE_COMPAT], [1],

    [Define in order to get some macros on AIX systems.])

  dnl Passfd prefers the POSIX use of msg.msg_control if the CMSG_* macros

  dnl are present, but can fall back to BSD 4.3 style of msg.msg_accrights.

  AC_CHECK_MEMBERS([struct msghdr.msg_accrights], [], [], [[

    #include <sys/types.h>

    #include <sys/socket.h>

  ]])

])