sysdeps/unix/sysv/linux/msgrcv.c

   1 /* Copyright (C) 1995, 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <errno.h>
  21 #include <sys/msg.h>
  22
  23 #include <sysdep.h>
  24 #include <sys/syscall.h>
  25
  26
  27 /* Kludge to work around Linux' restriction of only up to five
  28    arguments to a system call.  */
  29 struct ipc_kludge
  30   {
  31     void *msgp;
  32     long int msgtyp;
  33   };
  34
  35
  36 int
  37 msgrcv (msqid, msgp, msgsz, msgtyp, msgflg)
  38      int msqid;
  39      void *msgp;
  40      size_t msgsz;
  41      long int msgtyp;
  42      int msgflg;
  43 {
  44   /* The problem here is that Linux' calling convention only allows up to
  45      fives parameters to a system call.  */
  46   struct ipc_kludge tmp;
  47
  48   tmp.msgp = msgp;
  49   tmp.msgtyp = msgtyp;
  50
  51   return INLINE_SYSCALL (ipc, 5, IPCOP_msgrcv, msqid, msgsz, msgflg, &tmp);
  52 }