1 /*-
2  * Copyright (c) 1999 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
7  * NASA Ames Research Center.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the NetBSD
20  *	Foundation, Inc. and its contributors.
21  * 4. Neither the name of The NetBSD Foundation nor the names of its
22  *    contributors may be used to endorse or promote products derived
23  *    from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  *
37  * Obtained from: $NetBSD: shmtest.c,v 1.3 2002/07/20 08:36:26 grant Exp $
38  */
39 
40 /*
41  * Test the SVID-compatible Shared Memory facility.
42  */
43 
44 #include <sys/param.h>
45 #include <sys/ipc.h>
46 #include <sys/shm.h>
47 #include <sys/wait.h>
48 
49 #include <err.h>
50 #include <errno.h>
51 #include <signal.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <time.h>
56 #include <unistd.h>
57 
58 void	print_shmid_ds (struct shmid_ds *, mode_t);
59 void	sigsys_handler (int);
60 void	sigchld_handler (int);
61 void	cleanup (void);
62 void	receiver (void);
63 void	usage (void);
64 
65 const char *m_str = "The quick brown fox jumped over the lazy dog.";
66 
67 int	sender_shmid = -1;
68 pid_t	child_pid;
69 
70 key_t	shmkey;
71 
72 size_t	pgsize;
73 
74 int
main(argc,argv)75 main(argc, argv)
76 	int argc;
77 	char *argv[];
78 {
79 	struct sigaction sa;
80 	struct shmid_ds s_ds;
81 	sigset_t sigmask;
82 	char *shm_buf;
83 
84 	if (argc != 2)
85 		usage();
86 
87 	/*
88 	 * Install a SIGSYS handler so that we can exit gracefully if
89 	 * System V Shared Memory support isn't in the kernel.
90 	 */
91 	sa.sa_handler = sigsys_handler;
92 	sigemptyset(&sa.sa_mask);
93 	sa.sa_flags = 0;
94 	if (sigaction(SIGSYS, &sa, NULL) == -1)
95 		err(1, "sigaction SIGSYS");
96 
97 	/*
98 	 * Install and SIGCHLD handler to deal with all possible exit
99 	 * conditions of the receiver.
100 	 */
101 	sa.sa_handler = sigchld_handler;
102 	sigemptyset(&sa.sa_mask);
103 	sa.sa_flags = 0;
104 	if (sigaction(SIGCHLD, &sa, NULL) == -1)
105 		err(1, "sigaction SIGCHLD");
106 
107 	pgsize = sysconf(_SC_PAGESIZE);
108 
109 	shmkey = ftok(argv[1], 4160);
110 
111 	/*
112 	 * Initialize child_pid to ourselves to that the cleanup function
113 	 * works before we create the receiver.
114 	 */
115 	child_pid = getpid();
116 
117 	/*
118 	 * Make sure that when the sender exits, the message queue is
119 	 * removed.
120 	 */
121 	if (atexit(cleanup) == -1)
122 		err(1, "atexit");
123 
124 	if ((sender_shmid = shmget(shmkey, pgsize, IPC_CREAT | 0640)) == -1)
125 		err(1, "shmget");
126 
127 	if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1)
128 		err(1, "shmctl IPC_STAT");
129 
130 	print_shmid_ds(&s_ds, 0640);
131 
132 	s_ds.shm_perm.mode = (s_ds.shm_perm.mode & ~0777) | 0600;
133 
134 	if (shmctl(sender_shmid, IPC_SET, &s_ds) == -1)
135 		err(1, "shmctl IPC_SET");
136 
137 	memset(&s_ds, 0, sizeof(s_ds));
138 
139 	if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1)
140 		err(1, "shmctl IPC_STAT");
141 
142 	if ((s_ds.shm_perm.mode & 0777) != 0600)
143 		err(1, "IPC_SET of mode didn't hold");
144 
145 	print_shmid_ds(&s_ds, 0600);
146 
147 	if ((shm_buf = shmat(sender_shmid, NULL, 0)) == (void *) -1)
148 		err(1, "sender: shmat");
149 
150 	/*
151 	 * Write the test pattern into the shared memory buffer.
152 	 */
153 	strcpy(shm_buf, m_str);
154 
155 	switch ((child_pid = fork())) {
156 	case -1:
157 		err(1, "fork");
158 		/* NOTREACHED */
159 
160 	case 0:
161 		receiver();
162 		break;
163 
164 	default:
165 		break;
166 	}
167 
168 	/*
169 	 * Suspend forever; when we get SIGCHLD, the handler will exit.
170 	 */
171 	sigemptyset(&sigmask);
172 	(void) sigsuspend(&sigmask);
173 
174 	/*
175 	 * ...and any other signal is an unexpected error.
176 	 */
177 	errx(1, "sender: received unexpected signal");
178 }
179 
180 void
sigsys_handler(signo)181 sigsys_handler(signo)
182 	int signo;
183 {
184 
185 	errx(1, "System V Shared Memory support is not present in the kernel");
186 }
187 
188 void
sigchld_handler(signo)189 sigchld_handler(signo)
190 	int signo;
191 {
192 	struct shmid_ds s_ds;
193 	int cstatus;
194 
195 	/*
196 	 * Reap the child; if it exited successfully, then the test passed!
197 	 */
198 	if (waitpid(child_pid, &cstatus, 0) != child_pid)
199 		err(1, "waitpid");
200 
201 	if (WIFEXITED(cstatus) == 0)
202 		errx(1, "receiver exited abnormally");
203 
204 	if (WEXITSTATUS(cstatus) != 0)
205 		errx(1, "receiver exited with status %d",
206 		    WEXITSTATUS(cstatus));
207 
208 	/*
209 	 * If we get here, the child has exited normally, and thus
210 	 * we should exit normally too.  First, tho, we print out
211 	 * the final stats for the message queue.
212 	 */
213 
214 	if (shmctl(sender_shmid, IPC_STAT, &s_ds) == -1)
215 		err(1, "shmctl IPC_STAT");
216 
217 	print_shmid_ds(&s_ds, 0600);
218 
219 	exit(0);
220 }
221 
222 void
cleanup()223 cleanup()
224 {
225 
226 	/*
227 	 * If we're the sender, and it exists, remove the shared memory area.
228 	 */
229 	if (child_pid != 0 && sender_shmid != -1) {
230 		if (shmctl(sender_shmid, IPC_RMID, NULL) == -1)
231 			warn("shmctl IPC_RMID");
232 	}
233 }
234 
235 void
print_shmid_ds(sp,mode)236 print_shmid_ds(sp, mode)
237 	struct shmid_ds *sp;
238 	mode_t mode;
239 {
240 	uid_t uid = geteuid();
241 	gid_t gid = getegid();
242 
243 	printf("PERM: uid %d, gid %d, cuid %d, cgid %d, mode 0%o\n",
244 	    sp->shm_perm.uid, sp->shm_perm.gid,
245 	    sp->shm_perm.cuid, sp->shm_perm.cgid,
246 	    sp->shm_perm.mode & 0777);
247 
248 	printf("segsz %lu, lpid %d, cpid %d, nattch %u\n",
249 	    (u_long)sp->shm_segsz, sp->shm_lpid, sp->shm_cpid,
250 	    sp->shm_nattch);
251 
252 	printf("atime: %s", ctime(&sp->shm_atime));
253 	printf("dtime: %s", ctime(&sp->shm_dtime));
254 	printf("ctime: %s", ctime(&sp->shm_ctime));
255 
256 	/*
257 	 * Sanity check a few things.
258 	 */
259 
260 	if (sp->shm_perm.uid != uid || sp->shm_perm.cuid != uid)
261 		errx(1, "uid mismatch");
262 
263 	if (sp->shm_perm.gid != gid || sp->shm_perm.cgid != gid)
264 		errx(1, "gid mismatch");
265 
266 	if ((sp->shm_perm.mode & 0777) != mode)
267 		errx(1, "mode mismatch");
268 }
269 
270 void
usage()271 usage()
272 {
273 
274 	fprintf(stderr, "usage: %s keypath\n", getprogname());
275 	exit(1);
276 }
277 
278 void
receiver()279 receiver()
280 {
281 	int shmid;
282 	void *shm_buf;
283 
284 	if ((shmid = shmget(shmkey, pgsize, 0)) == -1)
285 		err(1, "receiver: shmget");
286 
287 	if ((shm_buf = shmat(shmid, NULL, 0)) == (void *) -1)
288 		err(1, "receiver: shmat");
289 
290 	printf("%s\n", (const char *)shm_buf);
291 	if (strcmp((const char *)shm_buf, m_str) != 0)
292 		err(1, "receiver: data isn't correct");
293 
294 	exit(0);
295 }
296