xref: /freebsd/sys/kern/sysv_ipc.c (revision 42c159fe388a3765f69860c84183700af37aca8a)
1 /* $FreeBSD$ */
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 
44 void (*shmfork_hook)(struct proc *, struct proc *) = NULL;
45 void (*shmexit_hook)(struct proc *) = NULL;
46 
47 /* called from kern_fork.c */
48 void
49 shmfork(p1, p2)
50 	struct proc *p1, *p2;
51 {
52 
53 	if (shmfork_hook != NULL)
54 		shmfork_hook(p1, p2);
55 	return;
56 }
57 
58 /* called from kern_exit.c */
59 void
60 shmexit(p)
61 	struct proc *p;
62 {
63 
64 	if (shmexit_hook != NULL)
65 		shmexit_hook(p);
66 	return;
67 }
68 
69 /*
70  * Check for ipc permission
71  */
72 
73 int
74 ipcperm(td, perm, mode)
75 	struct thread *td;
76 	struct ipc_perm *perm;
77 	int mode;
78 {
79 	struct ucred *cred = td->td_ucred;
80 
81 	/* Check for user match. */
82 	if (cred->cr_uid != perm->cuid && cred->cr_uid != perm->uid) {
83 		if (mode & IPC_M)
84 			return (suser_td(td) == 0 ? 0 : EPERM);
85 		/* Check for group match. */
86 		mode >>= 3;
87 		if (!groupmember(perm->gid, cred) &&
88 		    !groupmember(perm->cgid, cred))
89 			/* Check for `other' match. */
90 			mode >>= 3;
91 	}
92 
93 	if (mode & IPC_M)
94 		return (0);
95 	return ((mode & perm->mode) == mode ||
96 	    suser_td(td) == 0 ? 0 : EACCES);
97 }
98