1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
5 * Copyright (c) 2006 nCircle Network Security, Inc.
6 * All rights reserved.
7 *
8 * This software was developed by Robert N. M. Watson for the TrustedBSD
9 * Project under contract to nCircle Network Security, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by Herb Peyerl.
22 * 4. The name of Herb Peyerl may not be used to endorse or promote products
23 * derived from this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
26 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
29 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
30 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
34 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 *
36 * $NetBSD: sysv_ipc.c,v 1.9 1995/06/02 19:04:22 mycroft Exp $
37 */
38
39 #include <sys/cdefs.h>
40 #include "opt_sysvipc.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/sem.h>
45 #include <sys/shm.h>
46 #include <sys/ipc.h>
47 #include <sys/priv.h>
48 #include <sys/proc.h>
49 #include <sys/ucred.h>
50
51 #ifndef SYSVSHM
52 void (*shmfork_hook)(struct proc *, struct proc *) = NULL;
53 void (*shmexit_hook)(struct vmspace *) = NULL;
54
55 /* called from kern_fork.c */
56 void
shmfork(struct proc * p1,struct proc * p2)57 shmfork(struct proc *p1, struct proc *p2)
58 {
59 if (shmfork_hook != NULL)
60 shmfork_hook(p1, p2);
61 }
62
63 /* called from kern_exit.c */
64 void
shmexit(struct vmspace * vm)65 shmexit(struct vmspace *vm)
66 {
67 if (shmexit_hook != NULL)
68 shmexit_hook(vm);
69 }
70 #endif
71
72 /*
73 * Check for IPC permission.
74 *
75 * Note: The MAC Framework does not require any modifications to the
76 * ipcperm() function, as access control checks are performed throughout the
77 * implementation of each primitive. Those entry point calls complement the
78 * ipcperm() discertionary checks. Unlike file system discretionary access
79 * control, the original create of an object is given the same rights as the
80 * current owner.
81 */
82 int
ipcperm(struct thread * td,struct ipc_perm * perm,int acc_mode)83 ipcperm(struct thread *td, struct ipc_perm *perm, int acc_mode)
84 {
85 struct ucred *cred = td->td_ucred;
86 int error, obj_mode, dac_granted, priv_granted;
87
88 dac_granted = 0;
89 if (cred->cr_uid == perm->cuid || cred->cr_uid == perm->uid) {
90 obj_mode = perm->mode;
91 dac_granted |= IPC_M;
92 } else if (groupmember(perm->gid, cred) ||
93 groupmember(perm->cgid, cred)) {
94 obj_mode = perm->mode;
95 obj_mode <<= 3;
96 } else {
97 obj_mode = perm->mode;
98 obj_mode <<= 6;
99 }
100
101 /*
102 * While the System V IPC permission model allows IPC_M to be
103 * granted, as part of the mode, our implementation requires
104 * privilege to adminster the object if not the owner or creator.
105 */
106 #if 0
107 if (obj_mode & IPC_M)
108 dac_granted |= IPC_M;
109 #endif
110 if (obj_mode & IPC_R)
111 dac_granted |= IPC_R;
112 if (obj_mode & IPC_W)
113 dac_granted |= IPC_W;
114
115 /*
116 * Simple case: all required rights are granted by DAC.
117 */
118 if ((dac_granted & acc_mode) == acc_mode)
119 return (0);
120
121 /*
122 * Privilege is required to satisfy the request.
123 */
124 priv_granted = 0;
125 if ((acc_mode & IPC_M) && !(dac_granted & IPC_M)) {
126 error = priv_check(td, PRIV_IPC_ADMIN);
127 if (error == 0)
128 priv_granted |= IPC_M;
129 }
130
131 if ((acc_mode & IPC_R) && !(dac_granted & IPC_R)) {
132 error = priv_check(td, PRIV_IPC_READ);
133 if (error == 0)
134 priv_granted |= IPC_R;
135 }
136
137 if ((acc_mode & IPC_W) && !(dac_granted & IPC_W)) {
138 error = priv_check(td, PRIV_IPC_WRITE);
139 if (error == 0)
140 priv_granted |= IPC_W;
141 }
142
143 if (((dac_granted | priv_granted) & acc_mode) == acc_mode)
144 return (0);
145 else
146 return (EACCES);
147 }
148
149 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
150 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
151 void
ipcperm_old2new(struct ipc_perm_old * old,struct ipc_perm * new)152 ipcperm_old2new(struct ipc_perm_old *old, struct ipc_perm *new)
153 {
154
155 new->cuid = old->cuid;
156 new->cgid = old->cgid;
157 new->uid = old->uid;
158 new->gid = old->gid;
159 new->mode = old->mode;
160 new->seq = old->seq;
161 new->key = old->key;
162 }
163
164 void
ipcperm_new2old(struct ipc_perm * new,struct ipc_perm_old * old)165 ipcperm_new2old(struct ipc_perm *new, struct ipc_perm_old *old)
166 {
167
168 /* XXX: How to handle ID's > USHORT_MAX? */
169 old->cuid = new->cuid;
170 old->cgid = new->cgid;
171 old->uid = new->uid;
172 old->gid = new->gid;
173 old->mode = new->mode;
174 old->seq = new->seq;
175 old->key = new->key;
176 }
177 #endif
178
179 #ifdef COMPAT_FREEBSD32
180 #include <sys/mount.h>
181 #include <sys/socket.h>
182 #include <compat/freebsd32/freebsd32.h>
183 #include <compat/freebsd32/freebsd32_ipc.h>
184 #include <compat/freebsd32/freebsd32_proto.h>
185 #include <compat/freebsd32/freebsd32_signal.h>
186 #include <compat/freebsd32/freebsd32_syscall.h>
187 #include <compat/freebsd32/freebsd32_util.h>
188
189 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
190 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
191 void
freebsd32_ipcperm_old_in(struct ipc_perm_old32 * ip32,struct ipc_perm * ip)192 freebsd32_ipcperm_old_in(struct ipc_perm_old32 *ip32, struct ipc_perm *ip)
193 {
194
195 CP(*ip32, *ip, cuid);
196 CP(*ip32, *ip, cgid);
197 CP(*ip32, *ip, uid);
198 CP(*ip32, *ip, gid);
199 CP(*ip32, *ip, mode);
200 CP(*ip32, *ip, seq);
201 CP(*ip32, *ip, key);
202 }
203
204 void
freebsd32_ipcperm_old_out(struct ipc_perm * ip,struct ipc_perm_old32 * ip32)205 freebsd32_ipcperm_old_out(struct ipc_perm *ip, struct ipc_perm_old32 *ip32)
206 {
207
208 CP(*ip, *ip32, cuid);
209 CP(*ip, *ip32, cgid);
210 CP(*ip, *ip32, uid);
211 CP(*ip, *ip32, gid);
212 CP(*ip, *ip32, mode);
213 CP(*ip, *ip32, seq);
214 CP(*ip, *ip32, key);
215 }
216 #endif
217
218 void
freebsd32_ipcperm_in(struct ipc_perm32 * ip32,struct ipc_perm * ip)219 freebsd32_ipcperm_in(struct ipc_perm32 *ip32, struct ipc_perm *ip)
220 {
221
222 CP(*ip32, *ip, cuid);
223 CP(*ip32, *ip, cgid);
224 CP(*ip32, *ip, uid);
225 CP(*ip32, *ip, gid);
226 CP(*ip32, *ip, mode);
227 CP(*ip32, *ip, seq);
228 CP(*ip32, *ip, key);
229 }
230
231 void
freebsd32_ipcperm_out(struct ipc_perm * ip,struct ipc_perm32 * ip32)232 freebsd32_ipcperm_out(struct ipc_perm *ip, struct ipc_perm32 *ip32)
233 {
234
235 CP(*ip, *ip32, cuid);
236 CP(*ip, *ip32, cgid);
237 CP(*ip, *ip32, uid);
238 CP(*ip, *ip32, gid);
239 CP(*ip, *ip32, mode);
240 CP(*ip, *ip32, seq);
241 CP(*ip, *ip32, key);
242 }
243 #endif
244