sysdeps/unix/sysv/linux/msgctl.c

   1 /* Copyright (C) 1995-2015 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 <shlib-compat.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 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  50 int __old_msgctl (int, int, struct __old_msqid_ds *);
  51 #endif
  52 int __new_msgctl (int, int, struct msqid_ds *);
  53
  54 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  55 int
  56 attribute_compat_text_section
  57 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  58 {
  59   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, buf);
  60 }
  61 compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
  62 #endif
  63
  64 int
  65 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  66 {
  67 #if __ASSUME_IPC64 > 0
  68   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  69                          msqid, cmd | __IPC_64, 0, buf);
  70 #else
  71   switch (cmd) {
  72     case MSG_STAT:
  73     case IPC_STAT:
  74     case IPC_SET:
  75       break;
  76     default:
  77       return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  78                              msqid, cmd, 0, buf);
  79   }
  80
  81   {
  82     int result;
  83     struct __old_msqid_ds old;
  84
  85     /* Unfortunately there is no way how to find out for sure whether
  86        we should use old or new msgctl.  */
  87     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  88                              msqid, cmd | __IPC_64, 0, buf);
  89     if (result != -1 || errno != EINVAL)
  90       return result;
  91
  92     if (cmd == IPC_SET)
  93       {
  94         old.msg_perm.uid = buf->msg_perm.uid;
  95         old.msg_perm.gid = buf->msg_perm.gid;
  96         old.msg_perm.mode = buf->msg_perm.mode;
  97         old.msg_qbytes = buf->msg_qbytes;
  98         if (old.msg_perm.uid != buf->msg_perm.uid ||
  99             old.msg_perm.gid != buf->msg_perm.gid ||
 100             old.msg_qbytes != buf->msg_qbytes)
 101           {
 102             __set_errno (EINVAL);
 103             return -1;
 104           }
 105       }
 106     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, &old);
 107     if (result != -1 && cmd != IPC_SET)
 108       {
 109         memset(buf, 0, sizeof(*buf));
 110         buf->msg_perm.__key = old.msg_perm.__key;
 111         buf->msg_perm.uid = old.msg_perm.uid;
 112         buf->msg_perm.gid = old.msg_perm.gid;
 113         buf->msg_perm.cuid = old.msg_perm.cuid;
 114         buf->msg_perm.cgid = old.msg_perm.cgid;
 115         buf->msg_perm.mode = old.msg_perm.mode;
 116         buf->msg_perm.__seq = old.msg_perm.__seq;
 117         buf->msg_stime = old.msg_stime;
 118         buf->msg_rtime = old.msg_rtime;
 119         buf->msg_ctime = old.msg_ctime;
 120         buf->__msg_cbytes = old.__msg_cbytes;
 121         buf->msg_qnum = old.msg_qnum;
 122         buf->msg_qbytes = old.msg_qbytes;
 123         buf->msg_lspid = old.msg_lspid;
 124         buf->msg_lrpid = old.msg_lrpid;
 125       }
 126     return result;
 127   }
 128 #endif
 129 }
 130
 131 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);