sys/shmctl.c

   1 /*
   2  * Copyright (c) 2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #include <unistd.h>
  24 #include <sys/shm.h>
  25
  26 /*
  27  * Stub function to account for the differences in the ipc_perm structure,
  28  * while maintaining binary backward compatibility.
  29  *
  30  * This is only the legacy behavior.
  31  */
  32 extern int __shmctl(int, int, void *);
  33
  34 int
  35 shmctl(int shmid, int cmd, struct shmid_ds *ds)
  36 {
  37         struct __shmid_ds_old   *ds_old = (struct __shmid_ds_old *)ds;
  38         struct __shmid_ds_new   ds2;
  39         struct __shmid_ds_new   *ds_new = &ds2;
  40         int                     rv;
  41
  42 #define _UP_CVT(x)      ds_new-> x = ds_old-> x
  43 #define _DN_CVT(x)      ds_old-> x = ds_new-> x
  44
  45         if (cmd == IPC_SET) {
  46                 /* convert before call */
  47                 _UP_CVT(shm_perm.uid);
  48                 _UP_CVT(shm_perm.gid);
  49                 _UP_CVT(shm_perm.cuid);
  50                 _UP_CVT(shm_perm.cgid);
  51                 _UP_CVT(shm_perm.mode);
  52                 ds_new->shm_perm._seq = ds_old->shm_perm.seq;
  53                 ds_new->shm_perm._key = ds_old->shm_perm.key;
  54                 _UP_CVT(shm_segsz);
  55                 _UP_CVT(shm_lpid);
  56                 _UP_CVT(shm_cpid);
  57                 _UP_CVT(shm_nattch);
  58                 _UP_CVT(shm_atime);
  59                 _UP_CVT(shm_dtime);
  60                 _UP_CVT(shm_ctime);
  61                 _UP_CVT(shm_internal);
  62         }
  63
  64         rv = __shmctl(shmid, cmd, (void *)ds_new);
  65
  66         if (cmd == IPC_STAT) {
  67                 /* convert after call */
  68                 _DN_CVT(shm_perm.uid);  /* warning!  precision loss! */
  69                 _DN_CVT(shm_perm.gid);  /* warning!  precision loss! */
  70                 _DN_CVT(shm_perm.cuid); /* warning!  precision loss! */
  71                 _DN_CVT(shm_perm.cgid); /* warning!  precision loss! */
  72                 _DN_CVT(shm_perm.mode);
  73                 ds_old->shm_perm.seq = ds_new->shm_perm._seq;
  74                 ds_old->shm_perm.key = ds_new->shm_perm._key;
  75                 _DN_CVT(shm_segsz);
  76                 _DN_CVT(shm_lpid);
  77                 _DN_CVT(shm_cpid);
  78                 _DN_CVT(shm_nattch);
  79                 _DN_CVT(shm_atime);
  80                 _DN_CVT(shm_dtime);
  81                 _DN_CVT(shm_ctime);
  82                 _DN_CVT(shm_internal);
  83         }
  84
  85         return (rv);
  86 }