bsd/kern/sysv_ipc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*      $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
  29
  30 /*
  31  * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
  32  * All rights reserved.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions
  36  * are met:
  37  * 1. Redistributions of source code must retain the above copyright
  38  *    notice, this list of conditions and the following disclaimer.
  39  * 2. Redistributions in binary form must reproduce the above copyright
  40  *    notice, this list of conditions and the following disclaimer in the
  41  *    documentation and/or other materials provided with the distribution.
  42  * 3. All advertising materials mentioning features or use of this software
  43  *    must display the following acknowledgement:
  44  *      This product includes software developed by Herb Peyerl.
  45  * 4. The name of Herb Peyerl may not be used to endorse or promote products
  46  *    derived from this software without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  49  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  50  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  51  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  52  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  53  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  54  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  55  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  56  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  57  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  58  */
  59
  60
  61 #include <sys/param.h>
  62 #include <sys/ipc.h>
  63 #include <sys/ucred.h>
  64 #include <sys/kauth.h>
  65
  66
  67 /*
  68  * Check for ipc permission
  69  *
  70  * XXX: Should pass proc argument so that we can pass
  71  * XXX: proc->p_acflag to suser()
  72  */
  73
  74 /*
  75  * Returns:     0                       Success
  76  *              EPERM
  77  *              EACCES
  78  */
  79 int
  80 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode)
  81 {
  82
  83         if (!suser(cred, (u_short *)NULL))
  84                 return (0);
  85
  86         /* Check for user match. */
  87         if (kauth_cred_getuid(cred) != perm->cuid && kauth_cred_getuid(cred) != perm->uid) {
  88                 int is_member;
  89
  90                 if (mode & IPC_M)
  91                         return (EPERM);
  92                 /* Check for group match. */
  93                 mode >>= 3;
  94                 if ((kauth_cred_ismember_gid(cred, perm->gid, &is_member) || !is_member) &&
  95                     (kauth_cred_ismember_gid(cred, perm->cgid, &is_member) || !is_member)) {
  96                         /* Check for `other' match. */
  97                         mode >>= 3;
  98         }
  99         }
 100
 101         if (mode & IPC_M)
 102                 return (0);
 103
 104         return ((mode & perm->mode) == mode ? 0 : EACCES);
 105 }