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sysv_ipc.c revision 1.16.12.1 
      1 /*	$NetBSD: sysv_ipc.c,v 1.16.12.1 2006/05/24 15:50:41 tron Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Charles M. Hannum.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 __KERNEL_RCSID(0, "$NetBSD: sysv_ipc.c,v 1.16.12.1 2006/05/24 15:50:41 tron Exp $");
     41 
     42 #include <sys/param.h>
     43 #include <sys/kernel.h>
     44 #include <sys/proc.h>
     45 #include <sys/ipc.h>
     46 #include <sys/systm.h>
     47 #include <sys/mount.h>
     48 #include <sys/vnode.h>
     49 #include <sys/stat.h>
     50 #include <sys/kauth.h>
     51 
     52 /*
     53  * Check for ipc permission
     54  */
     55 
     56 int
     57 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode)
     58 {
     59 	mode_t mask;
     60 	int ismember = 0;
     61 
     62 	if (kauth_cred_geteuid(cred) == 0)
     63 		return (0);
     64 
     65 	if (mode == IPC_M) {
     66 		if (kauth_cred_geteuid(cred) == perm->uid ||
     67 		    kauth_cred_geteuid(cred) == perm->cuid)
     68 			return (0);
     69 		return (EPERM);
     70 	}
     71 
     72 	mask = 0;
     73 
     74 	if (kauth_cred_geteuid(cred) == perm->uid ||
     75 	    kauth_cred_geteuid(cred) == perm->cuid) {
     76 		if (mode & IPC_R)
     77 			mask |= S_IRUSR;
     78 		if (mode & IPC_W)
     79 			mask |= S_IWUSR;
     80 		return ((perm->mode & mask) == mask ? 0 : EACCES);
     81 	}
     82 
     83 	if (kauth_cred_getegid(cred) == perm->gid ||
     84 	    (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) ||
     85 	    kauth_cred_getegid(cred) == perm->cgid ||
     86 	    (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) {
     87 		if (mode & IPC_R)
     88 			mask |= S_IRGRP;
     89 		if (mode & IPC_W)
     90 			mask |= S_IWGRP;
     91 		return ((perm->mode & mask) == mask ? 0 : EACCES);
     92 	}
     93 
     94 	if (mode & IPC_R)
     95 		mask |= S_IROTH;
     96 	if (mode & IPC_W)
     97 		mask |= S_IWOTH;
     98 	return ((perm->mode & mask) == mask ? 0 : EACCES);
     99 }
    100