sysdeps/unix/sysv/linux/i386/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
  28 #include "kernel-features.h"
  29 #include <shlib-compat.h>
  30
  31 struct __old_msqid_ds
  32 {
  33   struct __old_ipc_perm msg_perm;       /* structure describing operation permission */
  34   struct msg *__msg_first;              /* pointer to first message on queue */
  35   struct msg *__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 *__wwait;           /* ??? */
  40   struct wait_queue *__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 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  51 int __old_msgctl (int, int, struct __old_msqid_ds *);
  52 #endif
  53 int __new_msgctl (int, int, struct msqid_ds *);
  54
  55 #ifdef __NR_getuid32
  56 # if __ASSUME_32BITUIDS == 0
  57 /* This variable is shared with all files that need to check for 32bit
  58    uids.  */
  59 extern int __libc_missing_32bit_uids;
  60 # endif
  61 #endif
  62
  63 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  64 int
  65 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  66 {
  67   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, buf);
  68 }
  69 compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
  70 #endif
  71
  72 int
  73 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  74 {
  75 #if __ASSUME_32BITUIDS > 0
  76   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd | __IPC_64, 0, buf);
  77 #else
  78   switch (cmd) {
  79     case MSG_STAT:
  80     case IPC_STAT:
  81     case IPC_SET:
  82       break;
  83     default:
  84       return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, buf);
  85   }
  86
  87   {
  88     int result;
  89     struct __old_msqid_ds old;
  90
  91 #ifdef __NR_getuid32
  92     if (__libc_missing_32bit_uids <= 0)
  93       {
  94         if (__libc_missing_32bit_uids < 0)
  95           {
  96             int save_errno = errno;
  97
  98             /* Test presence of new IPC by testing for getuid32 syscall.  */
  99             result = INLINE_SYSCALL (getuid32, 0);
 100             if (result == -1 && errno == ENOSYS)
 101               __libc_missing_32bit_uids = 1;
 102             else
 103               __libc_missing_32bit_uids = 0;
 104             __set_errno(save_errno);
 105           }
 106         if (__libc_missing_32bit_uids <= 0)
 107           {
 108             result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd | __IPC_64, 0, buf);
 109             return result;
 110           }
 111       }
 112 #endif
 113     if (cmd == IPC_SET)
 114       {
 115         old.msg_perm.uid = buf->msg_perm.uid;
 116         old.msg_perm.gid = buf->msg_perm.gid;
 117         old.msg_perm.mode = buf->msg_perm.mode;
 118         old.msg_qbytes = buf->msg_qbytes;
 119         if (old.msg_perm.uid != buf->msg_perm.uid ||
 120             old.msg_perm.gid != buf->msg_perm.gid ||
 121             old.msg_qbytes != buf->msg_qbytes)
 122           {
 123             __set_errno (EINVAL);
 124             return -1;
 125           }
 126       }
 127     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, &old);
 128     if (result != -1 && cmd != IPC_SET)
 129       {
 130         memset(buf, 0, sizeof(*buf));
 131         buf->msg_perm.__key = old.msg_perm.__key;
 132         buf->msg_perm.uid = old.msg_perm.uid;
 133         buf->msg_perm.gid = old.msg_perm.gid;
 134         buf->msg_perm.cuid = old.msg_perm.cuid;
 135         buf->msg_perm.cgid = old.msg_perm.cgid;
 136         buf->msg_perm.mode = old.msg_perm.mode;
 137         buf->msg_perm.__seq = old.msg_perm.__seq;
 138         buf->msg_stime = old.msg_stime;
 139         buf->msg_rtime = old.msg_rtime;
 140         buf->msg_ctime = old.msg_ctime;
 141         buf->__msg_cbytes = old.__msg_cbytes;
 142         buf->msg_qnum = old.msg_qnum;
 143         buf->msg_qbytes = old.msg_qbytes;
 144         buf->msg_lspid = old.msg_lspid;
 145         buf->msg_lrpid = old.msg_lrpid;
 146       }
 147     return result;
 148   }
 149 #endif
 150 }
 151
 152 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);