1 /* $NetBSD: shmtest.c,v 1.2 2001/02/19 22:44:41 cgd Exp $ */
2
3 /*-
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
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 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*
34 * Test the SVID-compatible Shared Memory facility.
35 */
36
37 #include <sys/ipc.h>
38 #include <sys/mman.h>
39 #include <sys/shm.h>
40 #include <sys/wait.h>
41
42 #include <err.h>
43 #include <errno.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <time.h>
49 #include <unistd.h>
50
51 int main(int, char *[]);
52 void print_shmid_ds(struct shmid_ds *, mode_t);
53 void sigsys_handler(int);
54 void sigchld_handler(int);
55 void cleanup(void);
56 void receiver(void);
57
58 const char *m_str = "The quick brown fox jumped over the lazy dog.";
59
60 int sender_shmid = -1;
61 pid_t child_pid;
62
63 key_t shmkey;
64
65 char keyname[] = "/tmp/msgtestXXXXXXXX";
66
67 int verbose;
68
69 size_t pgsize;
70
71 int
main(argc,argv)72 main(argc, argv)
73 int argc;
74 char *argv[];
75 {
76 struct sigaction sa;
77 struct shmid_ds s_ds;
78 sigset_t sigmask;
79 char *shm_buf;
80 int fd, ch;
81
82 if ((fd = mkstemp(keyname)) < 0)
83 err(1, "mkstemp");
84
85 close(fd);
86
87 while ((ch = getopt(argc, argv, "v")) != -1) {
88 switch (ch) {
89 case 'v':
90 verbose = 1;
91 break;
92 default:
93 fprintf(stderr, "Usage: shmtest [-v]\n");
94 exit(1);
95 }
96 }
97
98 /*
99 * Install a SIGSYS handler so that we can exit gracefully if
100 * System V Shared Memory support isn't in the kernel.
101 */
102 sa.sa_handler = sigsys_handler;
103 sigemptyset(&sa.sa_mask);
104 sa.sa_flags = 0;
105 if (sigaction(SIGSYS, &sa, NULL) == -1)
106 err(1, "sigaction SIGSYS");
107
108 /*
109 * Install and SIGCHLD handler to deal with all possible exit
110 * conditions of the receiver.
111 */
112 sa.sa_handler = sigchld_handler;
113 sigemptyset(&sa.sa_mask);
114 sa.sa_flags = 0;
115 if (sigaction(SIGCHLD, &sa, NULL) == -1)
116 err(1, "sigaction SIGCHLD");
117
118 pgsize = sysconf(_SC_PAGESIZE);
119
120 shmkey = ftok(argv[1], 4160);
121
122 /*
123 * Initialize child_pid to ourselves to that the cleanup function
124 * works before we create the receiver.
125 */
126 child_pid = getpid();
127
128 /*
129 * Make sure that when the sender exits, the message queue is
130 * removed.
131 */
132 if (atexit(cleanup) == -1)
133 err(1, "atexit");
134
135 if ((sender_shmid = shmget(shmkey, pgsize, IPC_CREAT | 0640)) == -1)
136 err(1, "shmget");
137
138 if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1)
139 err(1, "shmctl IPC_STAT");
140
141 if (verbose)
142 print_shmid_ds(&s_ds, 0640);
143
144 s_ds.shm_perm.mode = (s_ds.shm_perm.mode & ~0777) | 0600;
145
146 if (shmctl(sender_shmid, IPC_SET, &s_ds) == -1)
147 err(1, "shmctl IPC_SET");
148
149 memset(&s_ds, 0, sizeof(s_ds));
150
151 if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1)
152 err(1, "shmctl IPC_STAT");
153
154 if ((s_ds.shm_perm.mode & 0777) != 0600)
155 err(1, "IPC_SET of mode didn't hold");
156
157 if (verbose)
158 print_shmid_ds(&s_ds, 0600);
159
160 if ((shm_buf = shmat(sender_shmid, NULL, 0)) == (void *) -1)
161 err(1, "sender: shmat");
162
163 /*
164 * Write the test pattern into the shared memory buffer.
165 */
166 strlcpy(shm_buf, m_str, pgsize);
167
168 switch ((child_pid = fork())) {
169 case -1:
170 err(1, "fork");
171 /* NOTREACHED */
172
173 case 0:
174 receiver();
175 break;
176
177 default:
178 break;
179 }
180
181 /*
182 * Suspend forever; when we get SIGCHLD, the handler will exit.
183 */
184 sigemptyset(&sigmask);
185 (void) sigsuspend(&sigmask);
186
187 /*
188 * ...and any other signal is an unexpected error.
189 */
190 errx(1, "sender: received unexpected signal");
191 }
192
193 void
sigsys_handler(signo)194 sigsys_handler(signo)
195 int signo;
196 {
197
198 errx(1, "System V Shared Memory support is not present in the kernel");
199 }
200
201 void
sigchld_handler(signo)202 sigchld_handler(signo)
203 int signo;
204 {
205 struct shmid_ds s_ds;
206 int cstatus;
207
208 /*
209 * Reap the child; if it exited successfully, then the test passed!
210 */
211 if (waitpid(child_pid, &cstatus, 0) != child_pid)
212 err(1, "waitpid");
213
214 if (WIFEXITED(cstatus) == 0)
215 errx(1, "receiver exited abnormally");
216
217 if (WEXITSTATUS(cstatus) != 0)
218 errx(1, "receiver exited with status %d",
219 WEXITSTATUS(cstatus));
220
221 /*
222 * If we get here, the child has exited normally, and thus
223 * we should exit normally too. First, tho, we print out
224 * the final stats for the message queue.
225 */
226
227 if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1)
228 err(1, "shmctl IPC_STAT");
229
230 if (verbose)
231 print_shmid_ds(&s_ds, 0600);
232
233 exit(0);
234 }
235
236 void
cleanup()237 cleanup()
238 {
239
240 /*
241 * If we're the sender, and it exists, remove the shared memory area.
242 */
243 if (child_pid != 0 && sender_shmid != -1) {
244 if (shmctl(sender_shmid, IPC_RMID, NULL) == -1)
245 warn("shmctl IPC_RMID");
246 }
247
248 remove(keyname);
249 }
250
251 void
print_shmid_ds(sp,mode)252 print_shmid_ds(sp, mode)
253 struct shmid_ds *sp;
254 mode_t mode;
255 {
256 uid_t uid = geteuid();
257 gid_t gid = getegid();
258
259 printf("PERM: uid %u, gid %u, cuid %u, cgid %u, mode 0%o\n",
260 sp->shm_perm.uid, sp->shm_perm.gid,
261 sp->shm_perm.cuid, sp->shm_perm.cgid,
262 sp->shm_perm.mode & 0777);
263
264 printf("segsz %lu, lpid %d, cpid %d, nattch %u\n",
265 (u_long)sp->shm_segsz, sp->shm_lpid, sp->shm_cpid,
266 sp->shm_nattch);
267
268 printf("atime: %s", ctime(&sp->shm_atime));
269 printf("dtime: %s", ctime(&sp->shm_dtime));
270 printf("ctime: %s", ctime(&sp->shm_ctime));
271
272 /*
273 * Sanity check a few things.
274 */
275
276 if (sp->shm_perm.uid != uid || sp->shm_perm.cuid != uid)
277 errx(1, "uid mismatch");
278
279 if (sp->shm_perm.gid != gid || sp->shm_perm.cgid != gid)
280 errx(1, "gid mismatch");
281
282 if ((sp->shm_perm.mode & 0777) != mode)
283 errx(1, "mode mismatch");
284 }
285
286 void
receiver()287 receiver()
288 {
289 int shmid;
290 void *shm_buf;
291 void *block;
292
293 if ((shmid = shmget(shmkey, pgsize, 0)) == -1)
294 err(1, "receiver: shmget");
295
296 if ((shm_buf = shmat(shmid, NULL, 0)) == (void *) -1)
297 err(1, "receiver: shmat");
298
299 if (verbose)
300 printf("%.*s\n", (int)pgsize, (const char *)shm_buf);
301 if (strcmp((const char *)shm_buf, m_str) != 0)
302 errx(1, "receiver: data isn't correct");
303
304 /* mmap() a page to get a distinct, freeable address */
305 block = mmap(NULL, pgsize, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON,
306 -1, 0);
307 if (block == MAP_FAILED)
308 err(1, "receiver: mmap");
309
310 /* detach, then try to attach, conflicting with the mmap() */
311 if (shmdt(shm_buf) == -1)
312 err(1, "receiver: shmdt");
313 if ((shm_buf = shmat(shmid, block, 0)) != (void *) -1)
314 errx(1, "receiver: shmat(conflict) succeeded!");
315 if (errno != ENOMEM)
316 err(1, "receiver: shmat(conflict) wrong error");
317
318 /* free up that address and try again */
319 if (munmap(block, pgsize) == -1)
320 err(1, "receiver: munmap");
321 if ((shm_buf = shmat(shmid, block, 0)) == (void *) -1)
322 err(1, "receiver: shmat(fixed)");
323
324 if (shm_buf != block)
325 errx(1, "receiver: shmat not at expected address: %p != %p",
326 shm_buf, block);
327
328 if (verbose)
329 printf("%.*s\n", (int)pgsize, (const char *)shm_buf);
330 if (strcmp((const char *)shm_buf, m_str) != 0)
331 errx(1, "receiver: data isn't correct second time");
332
333 exit(0);
334 }
335