xref: /openbsd-src/sys/kern/sysv_ipc.c (revision a4afd6dad3fba28f80e70208181c06c482259988)
1 /*	$NetBSD: sysv_ipc.c,v 1.10 1995/06/03 05:53:28 mycroft Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Charles M. Hannum.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *      This product includes software developed by Charles M. Hannum.
17  * 4. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/proc.h>
35 #include <sys/ipc.h>
36 #include <sys/systm.h>
37 #include <sys/mount.h>
38 #include <sys/vnode.h>
39 
40 /*
41  * Check for ipc permission
42  */
43 
44 int
45 ipcperm(cred, perm, mode)
46 	struct ucred *cred;
47 	struct ipc_perm *perm;
48 	int mode;
49 {
50 
51 	if (mode == IPC_M) {
52 		if (cred->cr_uid == 0 ||
53 		    cred->cr_uid == perm->uid ||
54 		    cred->cr_uid == perm->cuid)
55 			return (0);
56 		return (EPERM);
57 	}
58 
59 	if (vaccess(perm->mode, perm->uid, perm->gid, mode, cred) == 0 ||
60 	    vaccess(perm->mode, perm->cuid, perm->cgid, mode, cred) == 0)
61 		return (0);
62 	return (EACCES);
63 }
64