1 /*-
2 * Copyright (c) 2007-2009 Dag-Erling Coïdan Smørgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include <sys/param.h>
32 #include <sys/wait.h>
33 #include <sys/event.h>
34
35 #include <fcntl.h>
36 #include <errno.h>
37 #include <signal.h>
38 #include <stdint.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43
44 #include <libutil.h>
45
46 /*
47 * We need a signal handler so kill(2) will interrupt the child
48 * instead of killing it.
49 */
50 static void
signal_handler(int sig)51 signal_handler(int sig)
52 {
53 (void)sig;
54 }
55
56 /*
57 * Test that pidfile_open() can create a pidfile and that pidfile_write()
58 * can write to it.
59 */
60 static const char *
test_pidfile_uncontested(void)61 test_pidfile_uncontested(void)
62 {
63 const char *fn = "test_pidfile_uncontested";
64 struct pidfh *pf;
65 pid_t other = 0;
66
67 unlink(fn);
68 pf = pidfile_open(fn, 0600, &other);
69 if (pf == NULL && other != 0)
70 return ("pidfile exists and is locked");
71 if (pf == NULL)
72 return (strerror(errno));
73 if (pidfile_write(pf) != 0) {
74 pidfile_close(pf);
75 unlink(fn);
76 return ("failed to write PID");
77 }
78 pidfile_close(pf);
79 unlink(fn);
80 return (NULL);
81 }
82
83 /*
84 * Test that pidfile_open() locks against self.
85 */
86 static const char *
test_pidfile_self(void)87 test_pidfile_self(void)
88 {
89 const char *fn = "test_pidfile_self";
90 struct pidfh *pf1, *pf2;
91 pid_t other = 0;
92 int serrno;
93
94 unlink(fn);
95 pf1 = pidfile_open(fn, 0600, &other);
96 if (pf1 == NULL && other != 0)
97 return ("pidfile exists and is locked");
98 if (pf1 == NULL)
99 return (strerror(errno));
100 if (pidfile_write(pf1) != 0) {
101 serrno = errno;
102 pidfile_close(pf1);
103 unlink(fn);
104 return (strerror(serrno));
105 }
106 // second open should fail
107 pf2 = pidfile_open(fn, 0600, &other);
108 if (pf2 != NULL) {
109 pidfile_close(pf1);
110 pidfile_close(pf2);
111 unlink(fn);
112 return ("managed to opened pidfile twice");
113 }
114 if (other != getpid()) {
115 pidfile_close(pf1);
116 unlink(fn);
117 return ("pidfile contained wrong PID");
118 }
119 pidfile_close(pf1);
120 unlink(fn);
121 return (NULL);
122 }
123
124 /*
125 * Common code for test_pidfile_{contested,inherited}.
126 */
127 static const char *
common_test_pidfile_child(const char * fn,int parent_open)128 common_test_pidfile_child(const char *fn, int parent_open)
129 {
130 struct pidfh *pf = NULL;
131 pid_t other = 0, pid = 0;
132 int fd[2], serrno, status;
133 struct kevent event, ke;
134 char ch;
135 int kq;
136
137 unlink(fn);
138 if (pipe(fd) != 0)
139 return (strerror(errno));
140
141 if (parent_open) {
142 pf = pidfile_open(fn, 0600, &other);
143 if (pf == NULL && other != 0)
144 return ("pidfile exists and is locked");
145 if (pf == NULL)
146 return (strerror(errno));
147 }
148
149 pid = fork();
150 if (pid == -1)
151 return (strerror(errno));
152 if (pid == 0) {
153 // child
154 close(fd[0]);
155 signal(SIGINT, signal_handler);
156 if (!parent_open) {
157 pf = pidfile_open(fn, 0600, &other);
158 if (pf == NULL && other != 0)
159 return ("pidfile exists and is locked");
160 if (pf == NULL)
161 return (strerror(errno));
162 }
163 if (pidfile_write(pf) != 0) {
164 serrno = errno;
165 pidfile_close(pf);
166 unlink(fn);
167 return (strerror(serrno));
168 }
169 if (pf == NULL)
170 _exit(1);
171 if (pidfile_write(pf) != 0)
172 _exit(2);
173 kq = kqueue();
174 if (kq == -1)
175 _exit(3);
176 EV_SET(&ke, SIGINT, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
177 /* Attach event to the kqueue. */
178 if (kevent(kq, &ke, 1, NULL, 0, NULL) != 0)
179 _exit(4);
180 /* Inform the parent we are ready to receive SIGINT */
181 if (write(fd[1], "*", 1) != 1)
182 _exit(5);
183 /* Wait for SIGINT received */
184 if (kevent(kq, NULL, 0, &event, 1, NULL) != 1)
185 _exit(6);
186 _exit(0);
187 }
188 // parent
189 close(fd[1]);
190 if (pf)
191 pidfile_close(pf);
192
193 // wait for the child to signal us
194 if (read(fd[0], &ch, 1) != 1) {
195 serrno = errno;
196 unlink(fn);
197 kill(pid, SIGTERM);
198 errno = serrno;
199 return (strerror(errno));
200 }
201
202 // We shouldn't be able to lock the same pidfile as our child
203 pf = pidfile_open(fn, 0600, &other);
204 if (pf != NULL) {
205 pidfile_close(pf);
206 unlink(fn);
207 return ("managed to lock contested pidfile");
208 }
209
210 // Failed to lock, but not because it was contested
211 if (other == 0) {
212 unlink(fn);
213 return (strerror(errno));
214 }
215
216 // Locked by the wrong process
217 if (other != pid) {
218 unlink(fn);
219 return ("pidfile contained wrong PID");
220 }
221
222 // check our child's fate
223 if (pf)
224 pidfile_close(pf);
225 unlink(fn);
226 if (kill(pid, SIGINT) != 0)
227 return (strerror(errno));
228 if (waitpid(pid, &status, 0) == -1)
229 return (strerror(errno));
230 if (WIFSIGNALED(status))
231 return ("child caught signal");
232 if (WEXITSTATUS(status) != 0)
233 return ("child returned non-zero status");
234
235 // success
236 return (NULL);
237 }
238
239 /*
240 * Test that pidfile_open() fails when attempting to open a pidfile that
241 * is already locked, and that it returns the correct PID.
242 */
243 static const char *
test_pidfile_contested(void)244 test_pidfile_contested(void)
245 {
246 const char *fn = "test_pidfile_contested";
247 const char *result;
248
249 result = common_test_pidfile_child(fn, 0);
250 return (result);
251 }
252
253 /*
254 * Test that the pidfile lock is inherited.
255 */
256 static const char *
test_pidfile_inherited(void)257 test_pidfile_inherited(void)
258 {
259 const char *fn = "test_pidfile_inherited";
260 const char *result;
261
262 result = common_test_pidfile_child(fn, 1);
263 return (result);
264 }
265
266 /*
267 * Make sure we handle relative pidfile paths correctly.
268 */
269 static const char *
test_pidfile_relative(void)270 test_pidfile_relative(void)
271 {
272 char path[PATH_MAX], pid[32], tmpdir[PATH_MAX];
273 struct pidfh *pfh;
274 int fd;
275
276 (void)snprintf(tmpdir, sizeof(tmpdir), "%s.XXXXXX", __func__);
277 if (mkdtemp(tmpdir) == NULL)
278 return (strerror(errno));
279 (void)snprintf(path, sizeof(path), "%s/pidfile", tmpdir);
280
281 pfh = pidfile_open(path, 0600, NULL);
282 if (pfh == NULL)
283 return (strerror(errno));
284 if (pidfile_write(pfh) != 0)
285 return (strerror(errno));
286 fd = open(path, O_RDONLY);
287 if (fd < 0)
288 return (strerror(errno));
289 if (read(fd, pid, sizeof(pid)) < 0)
290 return (strerror(errno));
291 if (atoi(pid) != getpid())
292 return ("pid mismatch");
293 if (close(fd) != 0)
294 return (strerror(errno));
295 if (pidfile_close(pfh) != 0)
296 return (strerror(errno));
297 return (NULL);
298 }
299
300 static struct test {
301 const char *name;
302 const char *(*func)(void);
303 } t[] = {
304 { "pidfile_uncontested", test_pidfile_uncontested },
305 { "pidfile_self", test_pidfile_self },
306 { "pidfile_contested", test_pidfile_contested },
307 { "pidfile_inherited", test_pidfile_inherited },
308 { "pidfile_relative", test_pidfile_relative },
309 };
310
311 int
main(void)312 main(void)
313 {
314 const char *result;
315 int i, nt;
316
317 nt = sizeof(t) / sizeof(*t);
318 printf("1..%d\n", nt);
319 for (i = 0; i < nt; ++i) {
320 if ((result = t[i].func()) != NULL)
321 printf("not ok %d - %s # %s\n", i + 1,
322 t[i].name, result);
323 else
324 printf("ok %d - %s\n", i + 1,
325 t[i].name);
326 }
327 exit(0);
328 }
329