FreeBSD/Linux Kernel Cross Reference
sys/kern/sysv_ipc.c
1 /* $NetBSD: sysv_ipc.c,v 1.21 2008/04/28 20:24:05 martin Exp $ */
2
3 /*-
4 * Copyright (c) 1998, 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Charles M. Hannum.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: sysv_ipc.c,v 1.21 2008/04/28 20:24:05 martin Exp $");
34
35 #include "opt_sysv.h"
36
37 #include <sys/param.h>
38 #include <sys/kernel.h>
39 #include <sys/proc.h>
40 #include <sys/ipc.h>
41 #ifdef SYSVMSG
42 #include <sys/msg.h>
43 #endif
44 #ifdef SYSVSEM
45 #include <sys/sem.h>
46 #endif
47 #ifdef SYSVSHM
48 #include <sys/shm.h>
49 #endif
50 #include <sys/systm.h>
51 #include <sys/malloc.h>
52 #include <sys/mount.h>
53 #include <sys/vnode.h>
54 #include <sys/stat.h>
55 #include <sys/sysctl.h>
56 #include <sys/kauth.h>
57
58 /*
59 * Check for ipc permission
60 */
61
62 int
63 ipcperm(kauth_cred_t cred, struct ipc_perm *perm, int mode)
64 {
65 mode_t mask;
66 int ismember = 0;
67
68 if (kauth_authorize_generic(cred, KAUTH_GENERIC_ISSUSER, NULL) == 0)
69 return (0);
70
71 if (mode == IPC_M) {
72 if (kauth_cred_geteuid(cred) == perm->uid ||
73 kauth_cred_geteuid(cred) == perm->cuid)
74 return (0);
75 return (EPERM);
76 }
77
78 mask = 0;
79
80 if (kauth_cred_geteuid(cred) == perm->uid ||
81 kauth_cred_geteuid(cred) == perm->cuid) {
82 if (mode & IPC_R)
83 mask |= S_IRUSR;
84 if (mode & IPC_W)
85 mask |= S_IWUSR;
86 return ((perm->mode & mask) == mask ? 0 : EACCES);
87 }
88
89 if (kauth_cred_getegid(cred) == perm->gid ||
90 (kauth_cred_ismember_gid(cred, perm->gid, &ismember) == 0 && ismember) ||
91 kauth_cred_getegid(cred) == perm->cgid ||
92 (kauth_cred_ismember_gid(cred, perm->cgid, &ismember) == 0 && ismember)) {
93 if (mode & IPC_R)
94 mask |= S_IRGRP;
95 if (mode & IPC_W)
96 mask |= S_IWGRP;
97 return ((perm->mode & mask) == mask ? 0 : EACCES);
98 }
99
100 if (mode & IPC_R)
101 mask |= S_IROTH;
102 if (mode & IPC_W)
103 mask |= S_IWOTH;
104 return ((perm->mode & mask) == mask ? 0 : EACCES);
105 }
106
107 /*
108 * sysctl helper routine for kern.ipc.sysvipc_info subtree.
109 */
110
111 #define FILL_PERM(src, dst) do { \
112 (dst)._key = (src)._key; \
113 (dst).uid = (src).uid; \
114 (dst).gid = (src).gid; \
115 (dst).cuid = (src).cuid; \
116 (dst).cgid = (src).cgid; \
117 (dst).mode = (src).mode; \
118 (dst)._seq = (src)._seq; \
119 } while (/*CONSTCOND*/ 0);
120
121 #define FILL_MSG(src, dst) do { \
122 FILL_PERM((src).msg_perm, (dst).msg_perm); \
123 (dst).msg_qnum = (src).msg_qnum; \
124 (dst).msg_qbytes = (src).msg_qbytes; \
125 (dst)._msg_cbytes = (src)._msg_cbytes; \
126 (dst).msg_lspid = (src).msg_lspid; \
127 (dst).msg_lrpid = (src).msg_lrpid; \
128 (dst).msg_stime = (src).msg_stime; \
129 (dst).msg_rtime = (src).msg_rtime; \
130 (dst).msg_ctime = (src).msg_ctime; \
131 } while (/*CONSTCOND*/ 0)
132
133 #define FILL_SEM(src, dst) do { \
134 FILL_PERM((src).sem_perm, (dst).sem_perm); \
135 (dst).sem_nsems = (src).sem_nsems; \
136 (dst).sem_otime = (src).sem_otime; \
137 (dst).sem_ctime = (src).sem_ctime; \
138 } while (/*CONSTCOND*/ 0)
139
140 #define FILL_SHM(src, dst) do { \
141 FILL_PERM((src).shm_perm, (dst).shm_perm); \
142 (dst).shm_segsz = (src).shm_segsz; \
143 (dst).shm_lpid = (src).shm_lpid; \
144 (dst).shm_cpid = (src).shm_cpid; \
145 (dst).shm_atime = (src).shm_atime; \
146 (dst).shm_dtime = (src).shm_dtime; \
147 (dst).shm_ctime = (src).shm_ctime; \
148 (dst).shm_nattch = (src).shm_nattch; \
149 } while (/*CONSTCOND*/ 0)
150
151 static int
152 sysctl_kern_sysvipc(SYSCTLFN_ARGS)
153 {
154 void *where = oldp;
155 size_t *sizep = oldlenp;
156 #ifdef SYSVMSG
157 struct msg_sysctl_info *msgsi = NULL;
158 #endif
159 #ifdef SYSVSEM
160 struct sem_sysctl_info *semsi = NULL;
161 #endif
162 #ifdef SYSVSHM
163 struct shm_sysctl_info *shmsi = NULL;
164 #endif
165 size_t infosize, dssize, tsize, buflen;
166 void *bf = NULL;
167 char *start;
168 int32_t nds;
169 int i, error, ret;
170
171 if (namelen != 1)
172 return EINVAL;
173
174 start = where;
175 buflen = *sizep;
176
177 switch (*name) {
178 case KERN_SYSVIPC_MSG_INFO:
179 #ifdef SYSVMSG
180 infosize = sizeof(msgsi->msginfo);
181 nds = msginfo.msgmni;
182 dssize = sizeof(msgsi->msgids[0]);
183 break;
184 #else
185 return EINVAL;
186 #endif
187 case KERN_SYSVIPC_SEM_INFO:
188 #ifdef SYSVSEM
189 infosize = sizeof(semsi->seminfo);
190 nds = seminfo.semmni;
191 dssize = sizeof(semsi->semids[0]);
192 break;
193 #else
194 return EINVAL;
195 #endif
196 case KERN_SYSVIPC_SHM_INFO:
197 #ifdef SYSVSHM
198 infosize = sizeof(shmsi->shminfo);
199 nds = shminfo.shmmni;
200 dssize = sizeof(shmsi->shmids[0]);
201 break;
202 #else
203 return EINVAL;
204 #endif
205 default:
206 return EINVAL;
207 }
208 /*
209 * Round infosize to 64 bit boundary if requesting more than just
210 * the info structure or getting the total data size.
211 */
212 if (where == NULL || *sizep > infosize)
213 infosize = roundup(infosize, sizeof(quad_t));
214 tsize = infosize + nds * dssize;
215
216 /* Return just the total size required. */
217 if (where == NULL) {
218 *sizep = tsize;
219 return 0;
220 }
221
222 /* Not enough room for even the info struct. */
223 if (buflen < infosize) {
224 *sizep = 0;
225 return ENOMEM;
226 }
227 bf = malloc(min(tsize, buflen), M_TEMP, M_WAITOK | M_ZERO);
228
229 switch (*name) {
230 #ifdef SYSVMSG
231 case KERN_SYSVIPC_MSG_INFO:
232 msgsi = (struct msg_sysctl_info *)bf;
233 msgsi->msginfo = msginfo;
234 break;
235 #endif
236 #ifdef SYSVSEM
237 case KERN_SYSVIPC_SEM_INFO:
238 semsi = (struct sem_sysctl_info *)bf;
239 semsi->seminfo = seminfo;
240 break;
241 #endif
242 #ifdef SYSVSHM
243 case KERN_SYSVIPC_SHM_INFO:
244 shmsi = (struct shm_sysctl_info *)bf;
245 shmsi->shminfo = shminfo;
246 break;
247 #endif
248 }
249 buflen -= infosize;
250
251 ret = 0;
252 if (buflen > 0) {
253 /* Fill in the IPC data structures. */
254 for (i = 0; i < nds; i++) {
255 if (buflen < dssize) {
256 ret = ENOMEM;
257 break;
258 }
259 switch (*name) {
260 #ifdef SYSVMSG
261 case KERN_SYSVIPC_MSG_INFO:
262 mutex_enter(&msgmutex);
263 FILL_MSG(msqs[i].msq_u, msgsi->msgids[i]);
264 mutex_exit(&msgmutex);
265 break;
266 #endif
267 #ifdef SYSVSEM
268 case KERN_SYSVIPC_SEM_INFO:
269 FILL_SEM(sema[i], semsi->semids[i]);
270 break;
271 #endif
272 #ifdef SYSVSHM
273 case KERN_SYSVIPC_SHM_INFO:
274 FILL_SHM(shmsegs[i], shmsi->shmids[i]);
275 break;
276 #endif
277 }
278 buflen -= dssize;
279 }
280 }
281 *sizep -= buflen;
282 error = copyout(bf, start, *sizep);
283 /* If copyout succeeded, use return code set earlier. */
284 if (error == 0)
285 error = ret;
286 if (bf)
287 free(bf, M_TEMP);
288 return error;
289 }
290
291 #undef FILL_PERM
292 #undef FILL_MSG
293 #undef FILL_SEM
294 #undef FILL_SHM
295
296 SYSCTL_SETUP(sysctl_ipc_setup, "sysctl kern.ipc subtree setup")
297 {
298 sysctl_createv(clog, 0, NULL, NULL,
299 CTLFLAG_PERMANENT,
300 CTLTYPE_NODE, "kern", NULL,
301 NULL, 0, NULL, 0,
302 CTL_KERN, CTL_EOL);
303
304 sysctl_createv(clog, 0, NULL, NULL,
305 CTLFLAG_PERMANENT,
306 CTLTYPE_NODE, "ipc",
307 SYSCTL_DESCR("SysV IPC options"),
308 NULL, 0, NULL, 0,
309 CTL_KERN, KERN_SYSVIPC, CTL_EOL);
310
311 sysctl_createv(clog, 0, NULL, NULL,
312 CTLFLAG_PERMANENT,
313 CTLTYPE_STRUCT, "sysvipc_info",
314 SYSCTL_DESCR("System V style IPC information"),
315 sysctl_kern_sysvipc, 0, NULL, 0,
316 CTL_KERN, KERN_SYSVIPC, KERN_SYSVIPC_INFO, CTL_EOL);
317 }
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