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
  30 struct __old_msqid_ds
  31 {
  32   struct __old_ipc_perm msg_perm;       /* structure describing operation permission */
  33   struct msg *__msg_first;              /* pointer to first message on queue */
  34   struct msg *__msg_last;               /* pointer to last message on queue */
  35   __time_t msg_stime;                   /* time of last msgsnd command */
  36   __time_t msg_rtime;                   /* time of last msgrcv command */
  37   __time_t msg_ctime;                   /* time of last change */
  38   struct wait_queue *__wwait;           /* ??? */
  39   struct wait_queue *__rwait;           /* ??? */
  40   unsigned short int __msg_cbytes;      /* current number of bytes on queue */
  41   unsigned short int msg_qnum;          /* number of messages currently on queue */
  42   unsigned short int msg_qbytes;        /* max number of bytes allowed on queue */
  43   __ipc_pid_t msg_lspid;                /* pid of last msgsnd() */
  44   __ipc_pid_t msg_lrpid;                /* pid of last msgrcv() */
  45 };
  46
  47 /* Allows to control internal state and destruction of message queue
  48    objects.  */
  49 int __old_msgctl (int, int, struct __old_msqid_ds *);
  50 int __new_msgctl (int, int, struct msqid_ds *);
  51
  52 #ifdef __NR_getuid32
  53 # if __ASSUME_32BITUIDS == 0
  54 /* This variable is shared with all files that need to check for 32bit
  55    uids.  */
  56 extern int __libc_missing_32bit_uids;
  57 # endif
  58 #endif
  59
  60 int
  61 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  62 {
  63   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, buf);
  64 }
  65
  66 int
  67 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  68 {
  69 #if __ASSUME_32BITUIDS > 0
  70   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd | __IPC_64, 0, 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, msqid, cmd, 0, buf);
  79   }
  80
  81   {
  82     int result;
  83     struct __old_msqid_ds old;
  84
  85 #ifdef __NR_getuid32
  86     if (__libc_missing_32bit_uids <= 0)
  87       {
  88         if (__libc_missing_32bit_uids < 0)
  89           {
  90             int save_errno = errno;
  91
  92             /* Test presence of new IPC by testing for getuid32 syscall.  */
  93             result = INLINE_SYSCALL (getuid32, 0);
  94             if (result == -1 && errno == ENOSYS)
  95               __libc_missing_32bit_uids = 1;
  96             else
  97               __libc_missing_32bit_uids = 0;
  98             __set_errno(save_errno);
  99           }
 100         if (__libc_missing_32bit_uids <= 0)
 101           {
 102             result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd | __IPC_64, 0, buf);
 103             return result;
 104           }
 105       }
 106 #endif
 107     if (cmd == IPC_SET)
 108       {
 109         old.msg_perm.uid = buf->msg_perm.uid;
 110         old.msg_perm.gid = buf->msg_perm.gid;
 111         old.msg_perm.mode = buf->msg_perm.mode;
 112         old.msg_qbytes = buf->msg_qbytes;
 113         if (old.msg_perm.uid != buf->msg_perm.uid ||
 114             old.msg_perm.gid != buf->msg_perm.gid ||
 115             old.msg_qbytes != buf->msg_qbytes)
 116           {
 117             __set_errno (EINVAL);
 118             return -1;
 119           }
 120       }
 121     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, &old);
 122     if (result != -1 && cmd != IPC_SET)
 123       {
 124         memset(buf, 0, sizeof(*buf));
 125         buf->msg_perm.__key = old.msg_perm.__key;
 126         buf->msg_perm.uid = old.msg_perm.uid;
 127         buf->msg_perm.gid = old.msg_perm.gid;
 128         buf->msg_perm.cuid = old.msg_perm.cuid;
 129         buf->msg_perm.cgid = old.msg_perm.cgid;
 130         buf->msg_perm.mode = old.msg_perm.mode;
 131         buf->msg_perm.__seq = old.msg_perm.__seq;
 132         buf->msg_stime = old.msg_stime;
 133         buf->msg_rtime = old.msg_rtime;
 134         buf->msg_ctime = old.msg_ctime;
 135         buf->__msg_cbytes = old.__msg_cbytes;
 136         buf->msg_qnum = old.msg_qnum;
 137         buf->msg_qbytes = old.msg_qbytes;
 138         buf->msg_lspid = old.msg_lspid;
 139         buf->msg_lrpid = old.msg_lrpid;
 140       }
 141     return result;
 142   }
 143 #endif
 144 }
 145
 146 #if defined PIC && DO_VERSIONING
 147 default_symbol_version (__new_msgctl, msgctl, GLIBC_2.2);
 148 symbol_version (__old_msgctl, msgctl, GLIBC_2.0);
 149 #else
 150 weak_alias (__new_msgctl, msgctl);
 151 #endif