sysdeps/unix/sysv/linux/i386/msgctl.c

   1 /* Copyright (C) 1995,1997,1998,2000,2004,2006 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <sys/msg.h>
  21 #include <ipc_priv.h>
  22
  23 #include <sysdep.h>
  24 #include <string.h>
  25 #include <sys/syscall.h>
  26 #include <bp-checks.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 *__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 #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 attribute_compat_text_section
  66 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  67 {
  68   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  69                          msqid, cmd, 0, CHECK_1 (buf));
  70 }
  71 compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
  72 #endif
  73
  74 int
  75 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  76 {
  77 #if __ASSUME_32BITUIDS > 0
  78   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  79                          msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
  80 #else
  81   switch (cmd) {
  82     case MSG_STAT:
  83     case IPC_STAT:
  84     case IPC_SET:
  85       break;
  86     default:
  87       return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  88                              msqid, cmd, 0, CHECK_1 (buf));
  89   }
  90
  91   {
  92     int result;
  93     struct __old_msqid_ds old;
  94
  95 #ifdef __NR_getuid32
  96     if (__libc_missing_32bit_uids <= 0)
  97       {
  98         if (__libc_missing_32bit_uids < 0)
  99           {
 100             int save_errno = errno;
 101
 102             /* Test presence of new IPC by testing for getuid32 syscall.  */
 103             result = INLINE_SYSCALL (getuid32, 0);
 104             if (result == -1 && errno == ENOSYS)
 105               __libc_missing_32bit_uids = 1;
 106             else
 107               __libc_missing_32bit_uids = 0;
 108             __set_errno(save_errno);
 109           }
 110         if (__libc_missing_32bit_uids <= 0)
 111           {
 112             result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
 113                                      msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
 114             return result;
 115           }
 116       }
 117 #endif
 118     if (cmd == IPC_SET)
 119       {
 120         old.msg_perm.uid = buf->msg_perm.uid;
 121         old.msg_perm.gid = buf->msg_perm.gid;
 122         old.msg_perm.mode = buf->msg_perm.mode;
 123         old.msg_qbytes = buf->msg_qbytes;
 124         if (old.msg_perm.uid != buf->msg_perm.uid ||
 125             old.msg_perm.gid != buf->msg_perm.gid ||
 126             old.msg_qbytes != buf->msg_qbytes)
 127           {
 128             __set_errno (EINVAL);
 129             return -1;
 130           }
 131       }
 132     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
 133                              msqid, cmd, 0, __ptrvalue (&old));
 134     if (result != -1 && cmd != IPC_SET)
 135       {
 136         memset(buf, 0, sizeof(*buf));
 137         buf->msg_perm.__key = old.msg_perm.__key;
 138         buf->msg_perm.uid = old.msg_perm.uid;
 139         buf->msg_perm.gid = old.msg_perm.gid;
 140         buf->msg_perm.cuid = old.msg_perm.cuid;
 141         buf->msg_perm.cgid = old.msg_perm.cgid;
 142         buf->msg_perm.mode = old.msg_perm.mode;
 143         buf->msg_perm.__seq = old.msg_perm.__seq;
 144         buf->msg_stime = old.msg_stime;
 145         buf->msg_rtime = old.msg_rtime;
 146         buf->msg_ctime = old.msg_ctime;
 147         buf->__msg_cbytes = old.__msg_cbytes;
 148         buf->msg_qnum = old.msg_qnum;
 149         buf->msg_qbytes = old.msg_qbytes;
 150         buf->msg_lspid = old.msg_lspid;
 151         buf->msg_lrpid = old.msg_lrpid;
 152       }
 153     return result;
 154   }
 155 #endif
 156 }
 157
 158 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);