sysdeps/unix/sysv/linux/msgctl.c

   1 /* Copyright (C) 1995, 1997, 1998, 2000 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 #include <ipc_priv.h>
  23
  24 #include <sysdep.h>
  25 #include <string.h>
  26 #include <sys/syscall.h>
  27 #include <shlib-compat.h>
  28 #include <bp-checks.h>
  29
  30 #include "kernel-features.h"
  31
  32 struct __old_msqid_ds
  33 {
  34   struct __old_ipc_perm msg_perm;       /* structure describing operation permission */
  35   struct msg *__unbounded __msg_first;  /* pointer to first message on queue */
  36   struct msg *__unbounded __msg_last;   /* pointer to last message on queue */
  37   __time_t msg_stime;                   /* time of last msgsnd command */
  38   __time_t msg_rtime;                   /* time of last msgrcv command */
  39   __time_t msg_ctime;                   /* time of last change */
  40   struct wait_queue *__unbounded __wwait; /* ??? */
  41   struct wait_queue *__unbounded __rwait; /* ??? */
  42   unsigned short int __msg_cbytes;      /* current number of bytes on queue */
  43   unsigned short int msg_qnum;          /* number of messages currently on queue */
  44   unsigned short int msg_qbytes;        /* max number of bytes allowed on queue */
  45   __ipc_pid_t msg_lspid;                /* pid of last msgsnd() */
  46   __ipc_pid_t msg_lrpid;                /* pid of last msgrcv() */
  47 };
  48
  49 /* Allows to control internal state and destruction of message queue
  50    objects.  */
  51 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  52 int __old_msgctl (int, int, struct __old_msqid_ds *);
  53 #endif
  54 int __new_msgctl (int, int, struct msqid_ds *);
  55
  56 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  57 int
  58 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  59 {
  60   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, CHECK_1 (buf));
  61 }
  62 compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
  63 #endif
  64
  65 int
  66 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  67 {
  68 #if __ASSUME_32BITUIDS > 0
  69   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  70                          msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
  71 #else
  72   switch (cmd) {
  73     case MSG_STAT:
  74     case IPC_STAT:
  75     case IPC_SET:
  76       break;
  77     default:
  78       return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  79                              msqid, cmd, 0, CHECK_1 (buf));
  80   }
  81
  82   {
  83     int save_errno = errno, result;
  84     struct __old_msqid_ds old;
  85
  86     /* Unfortunately there is no way how to find out for sure whether
  87        we should use old or new msgctl.  */
  88     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  89                              msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
  90     if (result != -1 || errno != EINVAL)
  91       return result;
  92
  93     __set_errno(save_errno);
  94     if (cmd == IPC_SET)
  95       {
  96         old.msg_perm.uid = buf->msg_perm.uid;
  97         old.msg_perm.gid = buf->msg_perm.gid;
  98         old.msg_perm.mode = buf->msg_perm.mode;
  99         old.msg_qbytes = buf->msg_qbytes;
 100         if (old.msg_perm.uid != buf->msg_perm.uid ||
 101             old.msg_perm.gid != buf->msg_perm.gid ||
 102             old.msg_qbytes != buf->msg_qbytes)
 103           {
 104             __set_errno (EINVAL);
 105             return -1;
 106           }
 107       }
 108     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
 109                              msqid, cmd, 0, __ptrvalue (&old));
 110     if (result != -1 && cmd != IPC_SET)
 111       {
 112         memset(buf, 0, sizeof(*buf));
 113         buf->msg_perm.__key = old.msg_perm.__key;
 114         buf->msg_perm.uid = old.msg_perm.uid;
 115         buf->msg_perm.gid = old.msg_perm.gid;
 116         buf->msg_perm.cuid = old.msg_perm.cuid;
 117         buf->msg_perm.cgid = old.msg_perm.cgid;
 118         buf->msg_perm.mode = old.msg_perm.mode;
 119         buf->msg_perm.__seq = old.msg_perm.__seq;
 120         buf->msg_stime = old.msg_stime;
 121         buf->msg_rtime = old.msg_rtime;
 122         buf->msg_ctime = old.msg_ctime;
 123         buf->__msg_cbytes = old.__msg_cbytes;
 124         buf->msg_qnum = old.msg_qnum;
 125         buf->msg_qbytes = old.msg_qbytes;
 126         buf->msg_lspid = old.msg_lspid;
 127         buf->msg_lrpid = old.msg_lrpid;
 128       }
 129     return result;
 130   }
 131 #endif
 132 }
 133
 134 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);