xref: /openbsd-src/sys/kern/sysv_ipc.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: sysv_ipc.c,v 1.6 2008/06/09 23:38:37 millert Exp $	*/
2 /*	$NetBSD: sysv_ipc.c,v 1.10 1995/06/03 05:53:28 mycroft Exp $	*/
3 
4 /*
5  * Copyright (c) 1995 Charles M. Hannum.  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 Charles M. Hannum.
18  * 4. The name of the author 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 #include <sys/mount.h>
39 #include <sys/vnode.h>
40 
41 /*
42  * Check for ipc permission
43  */
44 
45 int
46 ipcperm(struct ucred *cred, struct ipc_perm *perm, int mode)
47 {
48 
49 	if (mode == IPC_M) {
50 		if (cred->cr_uid == 0 ||
51 		    cred->cr_uid == perm->uid ||
52 		    cred->cr_uid == perm->cuid)
53 			return (0);
54 		return (EPERM);
55 	}
56 
57 	if (vaccess(VNON, perm->mode, perm->uid, perm->gid, mode, cred) == 0 ||
58 	    vaccess(VNON, perm->mode, perm->cuid, perm->cgid, mode, cred) == 0)
59 		return (0);
60 	return (EACCES);
61 }
62