sysdeps/unix/sysv/linux/alpha/msgctl.c

   1 /* Copyright (C) 1995,1997,1998,2000,2003,2006 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 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/msg.h>
  22 #include <ipc_priv.h>
  23
  24 #include <sysdep.h>
  25 #include <string.h>
  26 #include <sys/syscall.h>
  27 #include <bp-checks.h>
  28
  29 #include <kernel-features.h>
  30
  31 struct __old_msqid_ds
  32 {
  33   struct __old_ipc_perm msg_perm;       /* structure describing operation permission */
  34   struct msg *__unbounded __msg_first;  /* pointer to first message on queue */
  35   struct msg *__unbounded __msg_last;   /* pointer to last message on queue */
  36   __time_t msg_stime;                   /* time of last msgsnd command */
  37   __time_t msg_rtime;                   /* time of last msgrcv command */
  38   __time_t msg_ctime;                   /* time of last change */
  39   struct wait_queue *__unbounded __wwait; /* ??? */
  40   struct wait_queue *__unbounded __rwait; /* ??? */
  41   unsigned short int __msg_cbytes;      /* current number of bytes on queue */
  42   unsigned short int msg_qnum;          /* number of messages currently on queue */
  43   unsigned short int msg_qbytes;        /* max number of bytes allowed on queue */
  44   __ipc_pid_t msg_lspid;                /* pid of last msgsnd() */
  45   __ipc_pid_t msg_lrpid;                /* pid of last msgrcv() */
  46 };
  47
  48 /* Allows to control internal state and destruction of message queue
  49    objects.  */
  50 int __new_msgctl (int, int, struct msqid_ds *);
  51
  52 int
  53 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  54 {
  55   /* This is a misnomer -- Alpha had 32-bit uids at the beginning
  56      of time.  However, msg_qnum and msg_qbytes changed size at
  57      the same time the size of uid changed elsewhere.  */
  58 #if __ASSUME_32BITUIDS > 0
  59   return INLINE_SYSCALL (msgctl, 3, msqid, cmd | __IPC_64, CHECK_1 (buf));
  60 #else
  61   switch (cmd) {
  62     case MSG_STAT:
  63     case IPC_STAT:
  64     case IPC_SET:
  65       break;
  66     default:
  67       return INLINE_SYSCALL (msgctl, 3, msqid, cmd, CHECK_1 (buf));
  68   }
  69
  70   {
  71     int save_errno = errno, result;
  72     struct __old_msqid_ds old;
  73
  74     /* Unfortunately there is no way how to find out for sure whether
  75        we should use old or new msgctl.  */
  76     result = INLINE_SYSCALL (msgctl, 3, msqid, cmd | __IPC_64, CHECK_1 (buf));
  77     if (result != -1 || errno != EINVAL)
  78       return result;
  79
  80     __set_errno(save_errno);
  81     if (cmd == IPC_SET)
  82       {
  83         old.msg_perm.uid = buf->msg_perm.uid;
  84         old.msg_perm.gid = buf->msg_perm.gid;
  85         old.msg_perm.mode = buf->msg_perm.mode;
  86         old.msg_qbytes = buf->msg_qbytes;
  87         if (old.msg_perm.uid != buf->msg_perm.uid ||
  88             old.msg_perm.gid != buf->msg_perm.gid ||
  89             old.msg_qbytes != buf->msg_qbytes)
  90           {
  91             __set_errno (EINVAL);
  92             return -1;
  93           }
  94       }
  95     result = INLINE_SYSCALL (msgctl, 3, msqid, cmd, __ptrvalue (&old));
  96     if (result != -1 && cmd != IPC_SET)
  97       {
  98         memset(buf, 0, sizeof(*buf));
  99         buf->msg_perm.__key = old.msg_perm.__key;
 100         buf->msg_perm.uid = old.msg_perm.uid;
 101         buf->msg_perm.gid = old.msg_perm.gid;
 102         buf->msg_perm.cuid = old.msg_perm.cuid;
 103         buf->msg_perm.cgid = old.msg_perm.cgid;
 104         buf->msg_perm.mode = old.msg_perm.mode;
 105         buf->msg_perm.__seq = old.msg_perm.__seq;
 106         buf->msg_stime = old.msg_stime;
 107         buf->msg_rtime = old.msg_rtime;
 108         buf->msg_ctime = old.msg_ctime;
 109         buf->__msg_cbytes = old.__msg_cbytes;
 110         buf->msg_qnum = old.msg_qnum;
 111         buf->msg_qbytes = old.msg_qbytes;
 112         buf->msg_lspid = old.msg_lspid;
 113         buf->msg_lrpid = old.msg_lrpid;
 114       }
 115     return result;
 116   }
 117 #endif
 118 }
 119
 120 #include <shlib-compat.h>
 121 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);