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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    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 #include <bp-checks.h>
  28
  29 #include <kernel-features.h>
  30 #include <shlib-compat.h>
  31
  32 struct __old_msqid_ds
  33 {
  34   struct __old_ipc_perm msg_perm;       /* structure describing operation permission */
  35   struct msg *__unbounded __msg_first;  /* pointer to first message on queue */
  36   struct msg *__unbounded __msg_last;   /* pointer to last message on queue */
  37   __time_t msg_stime;                   /* time of last msgsnd command */
  38   __time_t msg_rtime;                   /* time of last msgrcv command */
  39   __time_t msg_ctime;                   /* time of last change */
  40   struct wait_queue *__unbounded __wwait; /* ??? */
  41   struct wait_queue *__unbounded __rwait; /* ??? */
  42   unsigned short int __msg_cbytes;      /* current number of bytes on queue */
  43   unsigned short int msg_qnum;          /* number of messages currently on queue */
  44   unsigned short int msg_qbytes;        /* max number of bytes allowed on queue */
  45   __ipc_pid_t msg_lspid;                /* pid of last msgsnd() */
  46   __ipc_pid_t msg_lrpid;                /* pid of last msgrcv() */
  47 };
  48
  49 /* Allows to control internal state and destruction of message queue
  50    objects.  */
  51 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  52 int __old_msgctl (int, int, struct __old_msqid_ds *);
  53 #endif
  54 int __new_msgctl (int, int, struct msqid_ds *);
  55
  56 #ifdef __NR_getuid32
  57 # if __ASSUME_32BITUIDS == 0
  58 /* This variable is shared with all files that need to check for 32bit
  59    uids.  */
  60 extern int __libc_missing_32bit_uids;
  61 # endif
  62 #endif
  63
  64 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
  65 int
  66 attribute_compat_text_section
  67 __old_msgctl (int msqid, int cmd, struct __old_msqid_ds *buf)
  68 {
  69   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  70                          msqid, cmd, 0, CHECK_1 (buf));
  71 }
  72 compat_symbol (libc, __old_msgctl, msgctl, GLIBC_2_0);
  73 #endif
  74
  75 int
  76 __new_msgctl (int msqid, int cmd, struct msqid_ds *buf)
  77 {
  78 #if __ASSUME_32BITUIDS > 0
  79   return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  80                          msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
  81 #else
  82   switch (cmd) {
  83     case MSG_STAT:
  84     case IPC_STAT:
  85     case IPC_SET:
  86       break;
  87     default:
  88       return INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
  89                              msqid, cmd, 0, CHECK_1 (buf));
  90   }
  91
  92   {
  93     int result;
  94     struct __old_msqid_ds old;
  95
  96 #ifdef __NR_getuid32
  97     if (__libc_missing_32bit_uids <= 0)
  98       {
  99         if (__libc_missing_32bit_uids < 0)
 100           {
 101             int save_errno = errno;
 102
 103             /* Test presence of new IPC by testing for getuid32 syscall.  */
 104             result = INLINE_SYSCALL (getuid32, 0);
 105             if (result == -1 && errno == ENOSYS)
 106               __libc_missing_32bit_uids = 1;
 107             else
 108               __libc_missing_32bit_uids = 0;
 109             __set_errno(save_errno);
 110           }
 111         if (__libc_missing_32bit_uids <= 0)
 112           {
 113             result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
 114                                      msqid, cmd | __IPC_64, 0, CHECK_1 (buf));
 115             return result;
 116           }
 117       }
 118 #endif
 119     if (cmd == IPC_SET)
 120       {
 121         old.msg_perm.uid = buf->msg_perm.uid;
 122         old.msg_perm.gid = buf->msg_perm.gid;
 123         old.msg_perm.mode = buf->msg_perm.mode;
 124         old.msg_qbytes = buf->msg_qbytes;
 125         if (old.msg_perm.uid != buf->msg_perm.uid ||
 126             old.msg_perm.gid != buf->msg_perm.gid ||
 127             old.msg_qbytes != buf->msg_qbytes)
 128           {
 129             __set_errno (EINVAL);
 130             return -1;
 131           }
 132       }
 133     result = INLINE_SYSCALL (ipc, 5, IPCOP_msgctl,
 134                              msqid, cmd, 0, __ptrvalue (&old));
 135     if (result != -1 && cmd != IPC_SET)
 136       {
 137         memset(buf, 0, sizeof(*buf));
 138         buf->msg_perm.__key = old.msg_perm.__key;
 139         buf->msg_perm.uid = old.msg_perm.uid;
 140         buf->msg_perm.gid = old.msg_perm.gid;
 141         buf->msg_perm.cuid = old.msg_perm.cuid;
 142         buf->msg_perm.cgid = old.msg_perm.cgid;
 143         buf->msg_perm.mode = old.msg_perm.mode;
 144         buf->msg_perm.__seq = old.msg_perm.__seq;
 145         buf->msg_stime = old.msg_stime;
 146         buf->msg_rtime = old.msg_rtime;
 147         buf->msg_ctime = old.msg_ctime;
 148         buf->__msg_cbytes = old.__msg_cbytes;
 149         buf->msg_qnum = old.msg_qnum;
 150         buf->msg_qbytes = old.msg_qbytes;
 151         buf->msg_lspid = old.msg_lspid;
 152         buf->msg_lrpid = old.msg_lrpid;
 153       }
 154     return result;
 155   }
 156 #endif
 157 }
 158
 159 versioned_symbol (libc, __new_msgctl, msgctl, GLIBC_2_2);