1 /*- 2 * Copyright (c) 2007-2009 Dag-Erling 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/param.h> 29 #include <sys/wait.h> 30 #include <sys/event.h> 31 32 #include <fcntl.h> 33 #include <errno.h> 34 #include <signal.h> 35 #include <stdint.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 #include <libutil.h> 42 43 /* 44 * We need a signal handler so kill(2) will interrupt the child 45 * instead of killing it. 46 */ 47 static void 48 signal_handler(int sig) 49 { 50 (void)sig; 51 } 52 53 /* 54 * Test that pidfile_open() can create a pidfile and that pidfile_write() 55 * can write to it. 56 */ 57 static const char * 58 test_pidfile_uncontested(void) 59 { 60 const char *fn = "test_pidfile_uncontested"; 61 struct pidfh *pf; 62 pid_t other = 0; 63 64 unlink(fn); 65 pf = pidfile_open(fn, 0600, &other); 66 if (pf == NULL && other != 0) 67 return ("pidfile exists and is locked"); 68 if (pf == NULL) 69 return (strerror(errno)); 70 if (pidfile_write(pf) != 0) { 71 pidfile_close(pf); 72 unlink(fn); 73 return ("failed to write PID"); 74 } 75 pidfile_close(pf); 76 unlink(fn); 77 return (NULL); 78 } 79 80 /* 81 * Test that pidfile_open() locks against self. 82 */ 83 static const char * 84 test_pidfile_self(void) 85 { 86 const char *fn = "test_pidfile_self"; 87 struct pidfh *pf1, *pf2; 88 pid_t other = 0; 89 int serrno; 90 91 unlink(fn); 92 pf1 = pidfile_open(fn, 0600, &other); 93 if (pf1 == NULL && other != 0) 94 return ("pidfile exists and is locked"); 95 if (pf1 == NULL) 96 return (strerror(errno)); 97 if (pidfile_write(pf1) != 0) { 98 serrno = errno; 99 pidfile_close(pf1); 100 unlink(fn); 101 return (strerror(serrno)); 102 } 103 // second open should fail 104 pf2 = pidfile_open(fn, 0600, &other); 105 if (pf2 != NULL) { 106 pidfile_close(pf1); 107 pidfile_close(pf2); 108 unlink(fn); 109 return ("managed to opened pidfile twice"); 110 } 111 if (other != getpid()) { 112 pidfile_close(pf1); 113 unlink(fn); 114 return ("pidfile contained wrong PID"); 115 } 116 pidfile_close(pf1); 117 unlink(fn); 118 return (NULL); 119 } 120 121 /* 122 * Common code for test_pidfile_{contested,inherited}. 123 */ 124 static const char * 125 common_test_pidfile_child(const char *fn, int parent_open) 126 { 127 struct pidfh *pf = NULL; 128 pid_t other = 0, pid = 0; 129 int fd[2], serrno, status; 130 struct kevent event, ke; 131 char ch; 132 int kq; 133 134 unlink(fn); 135 if (pipe(fd) != 0) 136 return (strerror(errno)); 137 138 if (parent_open) { 139 pf = pidfile_open(fn, 0600, &other); 140 if (pf == NULL && other != 0) 141 return ("pidfile exists and is locked"); 142 if (pf == NULL) 143 return (strerror(errno)); 144 } 145 146 pid = fork(); 147 if (pid == -1) 148 return (strerror(errno)); 149 if (pid == 0) { 150 // child 151 close(fd[0]); 152 signal(SIGINT, signal_handler); 153 if (!parent_open) { 154 pf = pidfile_open(fn, 0600, &other); 155 if (pf == NULL && other != 0) 156 return ("pidfile exists and is locked"); 157 if (pf == NULL) 158 return (strerror(errno)); 159 } 160 if (pidfile_write(pf) != 0) { 161 serrno = errno; 162 pidfile_close(pf); 163 unlink(fn); 164 return (strerror(serrno)); 165 } 166 if (pf == NULL) 167 _exit(1); 168 if (pidfile_write(pf) != 0) 169 _exit(2); 170 kq = kqueue(); 171 if (kq == -1) 172 _exit(3); 173 EV_SET(&ke, SIGINT, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL); 174 /* Attach event to the kqueue. */ 175 if (kevent(kq, &ke, 1, NULL, 0, NULL) != 0) 176 _exit(4); 177 /* Inform the parent we are ready to receive SIGINT */ 178 if (write(fd[1], "*", 1) != 1) 179 _exit(5); 180 /* Wait for SIGINT received */ 181 if (kevent(kq, NULL, 0, &event, 1, NULL) != 1) 182 _exit(6); 183 _exit(0); 184 } 185 // parent 186 close(fd[1]); 187 if (pf) 188 pidfile_close(pf); 189 190 // wait for the child to signal us 191 if (read(fd[0], &ch, 1) != 1) { 192 serrno = errno; 193 unlink(fn); 194 kill(pid, SIGTERM); 195 errno = serrno; 196 return (strerror(errno)); 197 } 198 199 // We shouldn't be able to lock the same pidfile as our child 200 pf = pidfile_open(fn, 0600, &other); 201 if (pf != NULL) { 202 pidfile_close(pf); 203 unlink(fn); 204 return ("managed to lock contested pidfile"); 205 } 206 207 // Failed to lock, but not because it was contested 208 if (other == 0) { 209 unlink(fn); 210 return (strerror(errno)); 211 } 212 213 // Locked by the wrong process 214 if (other != pid) { 215 unlink(fn); 216 return ("pidfile contained wrong PID"); 217 } 218 219 // check our child's fate 220 if (pf) 221 pidfile_close(pf); 222 unlink(fn); 223 if (kill(pid, SIGINT) != 0) 224 return (strerror(errno)); 225 if (waitpid(pid, &status, 0) == -1) 226 return (strerror(errno)); 227 if (WIFSIGNALED(status)) 228 return ("child caught signal"); 229 if (WEXITSTATUS(status) != 0) 230 return ("child returned non-zero status"); 231 232 // success 233 return (NULL); 234 } 235 236 /* 237 * Test that pidfile_open() fails when attempting to open a pidfile that 238 * is already locked, and that it returns the correct PID. 239 */ 240 static const char * 241 test_pidfile_contested(void) 242 { 243 const char *fn = "test_pidfile_contested"; 244 const char *result; 245 246 result = common_test_pidfile_child(fn, 0); 247 return (result); 248 } 249 250 /* 251 * Test that the pidfile lock is inherited. 252 */ 253 static const char * 254 test_pidfile_inherited(void) 255 { 256 const char *fn = "test_pidfile_inherited"; 257 const char *result; 258 259 result = common_test_pidfile_child(fn, 1); 260 return (result); 261 } 262 263 /* 264 * Make sure we handle relative pidfile paths correctly. 265 */ 266 static const char * 267 test_pidfile_relative(void) 268 { 269 char path[PATH_MAX], pid[32], tmpdir[PATH_MAX]; 270 struct pidfh *pfh; 271 int fd; 272 273 (void)snprintf(tmpdir, sizeof(tmpdir), "%s.XXXXXX", __func__); 274 if (mkdtemp(tmpdir) == NULL) 275 return (strerror(errno)); 276 (void)snprintf(path, sizeof(path), "%s/pidfile", tmpdir); 277 278 pfh = pidfile_open(path, 0600, NULL); 279 if (pfh == NULL) 280 return (strerror(errno)); 281 if (pidfile_write(pfh) != 0) 282 return (strerror(errno)); 283 fd = open(path, O_RDONLY); 284 if (fd < 0) 285 return (strerror(errno)); 286 memset(pid, 0, sizeof(pid)); 287 if (read(fd, pid, sizeof(pid) - 1) < 0) 288 return (strerror(errno)); 289 if (atoi(pid) != getpid()) 290 return ("pid mismatch"); 291 if (close(fd) != 0) 292 return (strerror(errno)); 293 if (pidfile_close(pfh) != 0) 294 return (strerror(errno)); 295 return (NULL); 296 } 297 298 static struct test { 299 const char *name; 300 const char *(*func)(void); 301 } t[] = { 302 { "pidfile_uncontested", test_pidfile_uncontested }, 303 { "pidfile_self", test_pidfile_self }, 304 { "pidfile_contested", test_pidfile_contested }, 305 { "pidfile_inherited", test_pidfile_inherited }, 306 { "pidfile_relative", test_pidfile_relative }, 307 }; 308 309 int 310 main(void) 311 { 312 const char *result; 313 int i, nt; 314 315 nt = sizeof(t) / sizeof(*t); 316 printf("1..%d\n", nt); 317 for (i = 0; i < nt; ++i) { 318 if ((result = t[i].func()) != NULL) 319 printf("not ok %d - %s # %s\n", i + 1, 320 t[i].name, result); 321 else 322 printf("ok %d - %s\n", i + 1, 323 t[i].name); 324 } 325 exit(0); 326 } 327