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 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 * 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 * 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 * 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 * 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 * 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 static struct test { 267 const char *name; 268 const char *(*func)(void); 269 } t[] = { 270 { "pidfile_uncontested", test_pidfile_uncontested }, 271 { "pidfile_self", test_pidfile_self }, 272 { "pidfile_contested", test_pidfile_contested }, 273 { "pidfile_inherited", test_pidfile_inherited }, 274 }; 275 276 int 277 main(void) 278 { 279 const char *result; 280 int i, nt; 281 282 nt = sizeof(t) / sizeof(*t); 283 printf("1..%d\n", nt); 284 for (i = 0; i < nt; ++i) { 285 if ((result = t[i].func()) != NULL) 286 printf("not ok %d - %s # %s\n", i + 1, 287 t[i].name, result); 288 else 289 printf("ok %d - %s\n", i + 1, 290 t[i].name); 291 } 292 exit(0); 293 } 294