sys/kern/sysv_ipc.c

   1 /* $FreeBSD: src/sys/kern/sysv_ipc.c,v 1.13.2.2 2000/07/01 14:33:49 bsd Exp $ */
   2 /*      $NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $ */
   3
   4 /*
   5  * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by Herb Peyerl.
  19  * 4. The name of Herb Peyerl may not be used to endorse or promote products
  20  *    derived from this software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/ipc.h>
  36 #include <sys/proc.h>
  37 #include <sys/priv.h>
  38 #include <sys/ucred.h>
  39
  40 /*
  41  * Check for ipc permission
  42  */
  43
  44 int
  45 ipcperm(struct proc *p, struct ipc_perm *perm, int mode)
  46 {
  47         struct ucred *cred = p->p_ucred;
  48
  49         /* Check for user match. */
  50         if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
  51                 if (mode & IPC_M)
  52                         return (priv_check_cred(cred, PRIV_ROOT, 0) == 0 ? 0 : EPERM);
  53                 /* Check for group match. */
  54                 mode >>= 3;
  55                 if (!groupmember(perm->gid, cred) &&
  56                     !groupmember(perm->cgid, cred))
  57                         /* Check for `other' match. */
  58                         mode >>= 3;
  59         }
  60
  61         if (mode & IPC_M)
  62                 return (0);
  63         return ((mode & perm->mode) == mode ||
  64                 priv_check_cred(cred, PRIV_ROOT, 0) == 0 ? 0 : EACCES);
  65 }