sysdeps/unix/sysv/linux/recvmmsg.c

   1 /* Copyright (C) 2010 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Andreas Schwab <schwab@redhat.com>, 2010.
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <sys/socket.h>
  22
  23 #include <sysdep-cancel.h>
  24 #include <sys/syscall.h>
  25 #include <kernel-features.h>
  26
  27
  28 #ifdef __NR_recvmmsg
  29 int
  30 recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
  31           const struct timespec *tmo)
  32 {
  33   if (SINGLE_THREAD_P)
  34     return INLINE_SYSCALL (recvmmsg, 5, fd, vmessages, vlen, flags, tmo);
  35
  36   int oldtype = LIBC_CANCEL_ASYNC ();
  37
  38   int result = INLINE_SYSCALL (recvmmsg, 5, fd, vmessages, vlen, flags, tmo);
  39
  40   LIBC_CANCEL_RESET (oldtype);
  41
  42   return result;
  43 }
  44 #elif defined __NR_socketcall
  45 # ifndef __ASSUME_RECVMMSG
  46 extern int __internal_recvmmsg (int fd, struct mmsghdr *vmessages,
  47                                 unsigned int vlen, int flags,
  48                                 const struct timespec *tmo)
  49      attribute_hidden;
  50
  51 static int have_recvmmsg;
  52
  53 int
  54 recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
  55           const struct timespec *tmo)
  56 {
  57   if (__builtin_expect (have_recvmmsg >= 0, 1))
  58     {
  59       int ret = __internal_recvmmsg (fd, vmessages, vlen, flags, tmo);
  60       /* The kernel returns -EINVAL for unknown socket operations.
  61          We need to convert that error to an ENOSYS error.  */
  62       if (__builtin_expect (ret < 0, 0)
  63           && have_recvmmsg == 0
  64           && errno == EINVAL)
  65         {
  66           /* Try another call, this time with an invalid file
  67              descriptor and all other parameters cleared.  This call
  68              will not cause any harm and it will return
  69              immediately.  */
  70           ret = __internal_recvmmsg (-1, 0, 0, 0, 0);
  71           if (errno == EINVAL)
  72             {
  73               have_recvmmsg = -1;
  74               __set_errno (ENOSYS);
  75             }
  76           else
  77             {
  78               have_recvmmsg = 1;
  79               __set_errno (EINVAL);
  80             }
  81           return -1;
  82         }
  83       return ret;
  84     }
  85   __set_errno (ENOSYS);
  86   return -1;
  87 }
  88 # else
  89 /* When __ASSUME_RECVMMSG recvmmsg is defined in internal_recvmmsg.S.  */
  90 # endif
  91 #else
  92 int
  93 recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags,
  94           const struct timespec *tmo)
  95 {
  96   __set_errno (ENOSYS);
  97   return -1;
  98 }
  99 stub_warning (recvmmsg)
 100 #endif