sysdeps/unix/sysv/linux/msgctl.c

   1 /* Copyright (C) 1995,1997,1998,2000,2002,2004,2006
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <errno.h>
  22 #include <sys/msg.h>
  23 #include <ipc_priv.h>
  24
  25 #include <sysdep.h>
  26 #include <string.h>
  27 #include <sys/syscall.h>
  28 #include <shlib-compat.h>
  29 #include <bp-checks.h>
  30
  31 #include <kernel-features.h>
  32
  33 struct __old_msqid_ds
  34 {
  35   struct __old_ipc_perm msg_perm;       /* structure describing operation permission */
  36   struct msg *__unbounded __msg_first;  /* pointer to first message on queue */
  37   struct msg *__unbounded __msg_last;   /* pointer to last message on queue */
  38   __time_t msg_stime;                   /* time of last msgsnd command */
  39   __time_t msg_rtime;                   /* time of last msgrcv command */
  40   __time_t msg_ctime;                   /* time of last change */
  41   struct wait_queue *__unbounded __wwait; /* ??? */
  42   struct wait_queue *__unbounded __rwait; /* ??? */
  43   unsigned short int __msg_cbytes;      /* current number of bytes on queue */
  44   unsigned short int msg_qnum;          /* number of messages currently on queue */
  45   unsigned short int msg_qbytes;        /* max number of bytes allowed on queue */
  46   __ipc_pid_t msg_lspid;                /* pid of last msgsnd() */
  47   __ipc_pid_t msg_lrpid;                /* pid of last msgrcv() */
  48 };
  49
  50 /* Allows to control internal state and destruction of message queue
  51    objects.  */
  52 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  53 int __old_msgctl (int, int, struct __old_msqid_ds *);
  54 #endif
  55 int __new_msgctl (int, int, struct msqid_ds *);
  56
  57 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  58 int
  59 attribute_compat_text_section
  60 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  61 {
  62   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl, msqid, cmd, 0, CHECK_1 (buf));
  63 }
  64 compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
  65 #endif
  66
  67 int
  68 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  69 {
  70 #if __ASSUME_IPC64 > 0
  71   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  72                          msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
  73 #else
  74   switch (cmd) {
  75     case MSG_STAT:
  76     case IPC_STAT:
  77     case IPC_SET:
  78       break;
  79     default:
  80       return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  81                              msqid, cmd, 0, CHECK_1 (buf));
  82   }
  83
  84   {
  85     int result;
  86     struct __old_msqid_ds old;
  87
  88     /* Unfortunately there is no way how to find out for sure whether
  89        we should use old or new msgctl.  */
  90     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  91                              msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
  92     if (result != -1 || errno != EINVAL)
  93       return result;
  94
  95     if (cmd == IPC_SET)
  96       {
  97         old.msg_perm.uid = buf->msg_perm.uid;
  98         old.msg_perm.gid = buf->msg_perm.gid;
  99         old.msg_perm.mode = buf->msg_perm.mode;
 100         old.msg_qbytes = buf->msg_qbytes;
 101         if (old.msg_perm.uid != buf->msg_perm.uid ||
 102             old.msg_perm.gid != buf->msg_perm.gid ||
 103             old.msg_qbytes != buf->msg_qbytes)
 104           {
 105             __set_errno (EINVAL);
 106             return -1;
 107           }
 108       }
 109     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
 110                              msqid, cmd, 0, __ptrvalue (&old));
 111     if (result != -1 && cmd != IPC_SET)
 112       {
 113         memset(buf, 0, sizeof(*buf));
 114         buf->msg_perm.__key = old.msg_perm.__key;
 115         buf->msg_perm.uid = old.msg_perm.uid;
 116         buf->msg_perm.gid = old.msg_perm.gid;
 117         buf->msg_perm.cuid = old.msg_perm.cuid;
 118         buf->msg_perm.cgid = old.msg_perm.cgid;
 119         buf->msg_perm.mode = old.msg_perm.mode;
 120         buf->msg_perm.__seq = old.msg_perm.__seq;
 121         buf->msg_stime = old.msg_stime;
 122         buf->msg_rtime = old.msg_rtime;
 123         buf->msg_ctime = old.msg_ctime;
 124         buf->__msg_cbytes = old.__msg_cbytes;
 125         buf->msg_qnum = old.msg_qnum;
 126         buf->msg_qbytes = old.msg_qbytes;
 127         buf->msg_lspid = old.msg_lspid;
 128         buf->msg_lrpid = old.msg_lrpid;
 129       }
 130     return result;
 131   }
 132 #endif
 133 }
 134
 135 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);