sysdeps/unix/sysv/linux/recvmsg.c

   1 /* Linux recvmsg syscall wrapper.
   2    Copyright (C) 2016-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <sys/socket.h>
  20 #include <sysdep-cancel.h>
  21 #include <socketcall.h>
  22
  23 static int
  24 __recvmsg_syscall (int fd, struct msghdr *msg, int flags)
  25 {
  26 #ifdef __ASSUME_RECVMSG_SYSCALL
  27   return SYSCALL_CANCEL (recvmsg, fd, msg, flags);
  28 #else
  29   return SOCKETCALL_CANCEL (recvmsg, fd, msg, flags);
  30 #endif
  31 }
  32
  33 ssize_t
  34 __libc_recvmsg64 (int fd, struct msghdr *msg, int flags)
  35 {
  36   ssize_t r;
  37 #if __TIMESIZE != 64
  38   socklen_t orig_controllen = msg != NULL ? msg->msg_controllen : 0;
  39 #endif
  40
  41   r = __recvmsg_syscall (fd, msg, flags);
  42
  43 #if __TIMESIZE != 64
  44   if (r >= 0 && orig_controllen != 0)
  45     __convert_scm_timestamps (msg, orig_controllen);
  46 #endif
  47
  48   return r;
  49 }
  50 #if __TIMESIZE != 64
  51 weak_alias (__libc_recvmsg64, __recvmsg64)
  52
  53 ssize_t
  54 __libc_recvmsg (int fd, struct msghdr *msg, int flags)
  55 {
  56   return __recvmsg_syscall (fd, msg, flags);
  57 }
  58 #endif
  59 weak_alias (__libc_recvmsg, recvmsg)
  60 weak_alias (__libc_recvmsg, __recvmsg)