bsd/kern/sysv_ipc.c

   1 /*
   2  * Copyright (c) 2000 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 /*      $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
  24
  25 /*
  26  * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
  27  * All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by Herb Peyerl.
  40  * 4. The name of Herb Peyerl may not be used to endorse or promote products
  41  *    derived from this software without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  44  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  45  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  46  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  47  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  48  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  49  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  50  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  51  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  52  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  53  */
  54
  55
  56 #include <sys/param.h>
  57 #include <sys/ipc.h>
  58 #include <sys/ucred.h>
  59 #include <sys/kauth.h>
  60
  61
  62 /*
  63  * Check for ipc permission
  64  *
  65  * XXX: Should pass proc argument so that we can pass
  66  * XXX: proc->p_acflag to suser()
  67  */
  68
  69 int
  70 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode)
  71 {
  72
  73         if (!suser(cred, (u_short *)NULL))
  74                 return (0);
  75
  76         /* Check for user match. */
  77         if (kauth_cred_getuid(cred) != perm->cuid && kauth_cred_getuid(cred) != perm->uid) {
  78                 int is_member;
  79
  80                 if (mode & IPC_M)
  81                         return (EPERM);
  82                 /* Check for group match. */
  83                 mode >>= 3;
  84                 if ((kauth_cred_ismember_gid(cred, perm->gid, &is_member) || !is_member) &&
  85                     (kauth_cred_ismember_gid(cred, perm->cgid, &is_member) || !is_member))
  86                         /* Check for `other' match. */
  87                         mode >>= 3;
  88         }
  89
  90         if (mode & IPC_M)
  91                 return (0);
  92         return ((mode & perm->mode) == mode ? 0 : EACCES);
  93 }