sys/semctl.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 <stdarg.h>
  25 #include <sys/sem.h>
  26
  27 #if !__DARWIN_UNIX03
  28 #include <errno.h>
  29 /*
  30  * Because KERNEL is defined, including errno.h doesn't define errno, so
  31  * we have to do it ourselves.
  32  */
  33 extern int * __error(void);
  34 #define errno (*__error())
  35 #endif /* !__DARWIN_UNIX03 */
  36
  37 /*
  38  * Stub function to account for the differences in the ipc_perm structure,
  39  * while maintaining binary backward compatibility.
  40  */
  41 extern int __semctl(int semid, int semnum, int cmd, void *);
  42
  43 int
  44 semctl(int semid, int semnum, int cmd, ...)
  45 {
  46         va_list                 ap;
  47         int                     rv;
  48         int                     val = 0;
  49 #if __DARWIN_UNIX03
  50         struct __semid_ds_new   *ds;
  51
  52         va_start(ap, cmd);
  53         if (cmd == SETVAL) {
  54                 val = va_arg(ap, int);
  55                 rv = __semctl(semid, semnum, cmd, (void *)val);
  56         } else {
  57                 ds = va_arg(ap, struct __semid_ds_new *);
  58                 rv = __semctl(semid, semnum, cmd, (void *)ds);
  59         }
  60         va_end(ap);
  61
  62         return rv;
  63 #else   /* !__DARWIN_UNIX03 */
  64         struct __semid_ds_new   ds;
  65         struct __semid_ds_new   *ds_new = &ds;
  66         struct __semid_ds_old   *ds_old = NULL;
  67
  68         va_start(ap, cmd);
  69         if (cmd == SETVAL)
  70                 val = va_arg(ap, int);
  71         else
  72                 ds_old = va_arg(ap, struct __semid_ds_old *);
  73         va_end(ap);
  74
  75 #define _UP_CVT(x)      ds_new-> x = ds_old-> x
  76 #define _DN_CVT(x)      ds_old-> x = ds_new-> x
  77
  78         if ((cmd == IPC_SET || cmd == IPC_STAT) && ds_old == NULL) {
  79                 /* Return EFAULT if ds_old is NULL (like the kernel would do) */
  80                 errno = EFAULT;
  81                 return -1;
  82         }
  83         if (cmd == IPC_SET) {
  84                 /* convert before call */
  85                 _UP_CVT(sem_perm.uid);
  86                 _UP_CVT(sem_perm.gid);
  87                 _UP_CVT(sem_perm.cuid);
  88                 _UP_CVT(sem_perm.cgid);
  89                 _UP_CVT(sem_perm.mode);
  90                 ds_new->sem_perm._seq = ds_old->sem_perm.seq;
  91                 ds_new->sem_perm._key = ds_old->sem_perm.key;
  92                 _UP_CVT(sem_base);
  93                 _UP_CVT(sem_nsems);
  94                 _UP_CVT(sem_otime);
  95                 _UP_CVT(sem_pad1);      /* binary compatibility */
  96                 _UP_CVT(sem_ctime);
  97                 _UP_CVT(sem_pad2);      /* binary compatibility */
  98                 _UP_CVT(sem_pad3[0]);   /* binary compatibility */
  99                 _UP_CVT(sem_pad3[1]);   /* binary compatibility */
 100                 _UP_CVT(sem_pad3[2]);   /* binary compatibility */
 101                 _UP_CVT(sem_pad3[3]);   /* binary compatibility */
 102         }
 103         switch (cmd) {
 104         case SETVAL:
 105                 /* syscall must use LP64 quantities */
 106                 rv = __semctl(semid, semnum, cmd, (void *)val);
 107                 break;
 108         case IPC_SET:
 109         case IPC_STAT:
 110                 rv = __semctl(semid, semnum, cmd, ds_new);
 111                 break;
 112         default:
 113                 rv = __semctl(semid, semnum, cmd, ds_old);
 114                 break;
 115         }
 116
 117         if (cmd == IPC_STAT) {
 118                 /* convert after call */
 119                 _DN_CVT(sem_perm.uid);  /* warning!  precision loss! */
 120                 _DN_CVT(sem_perm.gid);  /* warning!  precision loss! */
 121                 _DN_CVT(sem_perm.cuid); /* warning!  precision loss! */
 122                 _DN_CVT(sem_perm.cgid); /* warning!  precision loss! */
 123                 _DN_CVT(sem_perm.mode);
 124                 ds_old->sem_perm.seq = ds_new->sem_perm._seq;
 125                 ds_old->sem_perm.key = ds_new->sem_perm._key;
 126                 _DN_CVT(sem_base);
 127                 _DN_CVT(sem_nsems);
 128                 _DN_CVT(sem_otime);
 129                 _DN_CVT(sem_pad1);      /* binary compatibility */
 130                 _DN_CVT(sem_ctime);
 131                 _DN_CVT(sem_pad2);      /* binary compatibility */
 132                 _DN_CVT(sem_pad3[0]);   /* binary compatibility */
 133                 _DN_CVT(sem_pad3[1]);   /* binary compatibility */
 134                 _DN_CVT(sem_pad3[2]);   /* binary compatibility */
 135                 _DN_CVT(sem_pad3[3]);   /* binary compatibility */
 136         }
 137
 138         return (rv);
 139 #endif  /* !__DARWIN_UNIX03 */
 140 }