sysv_ipc.c revision 69449 
1/* $FreeBSD: head/sys/kern/sysv_ipc.c 69449 2000-12-01 08:57:47Z alfred $ */
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 "opt_sysvipc.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/sem.h>
39#include <sys/shm.h>
40#include <sys/ipc.h>
41#include <sys/proc.h>
42#include <sys/ucred.h>
43
44void (*semexit_hook)(struct proc *) = NULL;
45void (*shmfork_hook)(struct proc *, struct proc *) = NULL;
46void (*shmexit_hook)(struct proc *) = NULL;
47
48/* called from kern_exit.c */
49void
50semexit(p)
51	struct proc *p;
52{
53
54	if (semexit_hook != NULL)
55		semexit_hook(p);
56	return;
57}
58
59/* called from kern_fork.c */
60void
61shmfork(p1, p2)
62	struct proc *p1, *p2;
63{
64
65	if (shmfork_hook != NULL)
66		shmfork_hook(p1, p2);
67	return;
68}
69
70/* called from kern_exit.c */
71void
72shmexit(p)
73	struct proc *p;
74{
75
76	if (shmexit_hook != NULL)
77		shmexit_hook(p);
78	return;
79}
80
81/*
82 * Check for ipc permission
83 */
84
85int
86ipcperm(p, perm, mode)
87	struct proc *p;
88	struct ipc_perm *perm;
89	int mode;
90{
91	struct ucred *cred = p->p_ucred;
92
93	/* Check for user match. */
94	if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
95		if (mode & IPC_M)
96			return (suser(p) == 0 ? 0 : EPERM);
97		/* Check for group match. */
98		mode >>= 3;
99		if (!groupmember(perm->gid, cred) &&
100		    !groupmember(perm->cgid, cred))
101			/* Check for `other' match. */
102			mode >>= 3;
103	}
104
105	if (mode & IPC_M)
106		return (0);
107	return ((mode & perm->mode) == mode || suser(p) == 0 ? 0 : EACCES);
108}
109