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sysv_ipc.c revision 1.7 
      1 /*	$NetBSD: sysv_ipc.c,v 1.7 1994/06/29 06:33:11 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994 Herb Peyerl <hpeyerl (at) novatel.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *      This product includes software developed by Herb Peyerl.
     18  * 4. The name of Herb Peyerl may not be used to endorse or promote products
     19  *    derived from this software without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/param.h>
     34 #include <sys/kernel.h>
     35 #include <sys/proc.h>
     36 #include <sys/ipc.h>
     37 #include <sys/systm.h>
     38 
     39 /*
     40  * Check for ipc permission
     41  */
     42 
     43 int
     44 ipcperm(cred, perm, mode)
     45 	struct ucred *cred;
     46 	struct ipc_perm *perm;
     47 	int mode;
     48 {
     49 
     50 	if (cred->cr_uid == 0)
     51 		return (0);
     52 
     53 	/* Check for user match. */
     54 	if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
     55 		if (mode & IPC_M)
     56 			return (EPERM);
     57 		/* Check for group match. */
     58 		mode >>= 3;
     59 		if (!groupmember(perm->gid, cred) &&
     60 		    !groupmember(perm->cgid, cred))
     61 			/* Check for `other' match. */
     62 			mode >>= 3;
     63 	}
     64 
     65 	if (mode & IPC_M)
     66 		return (0);
     67 	return ((mode & perm->mode) == mode ? 0 : EACCES);
     68 }
     69