1 /*- 2 * Copyright (c) 2003-2004 Sean M. Kelly <smkelly@FreeBSD.org> 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 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * Software watchdog daemon. 29 */ 30 31 #include <sys/types.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/param.h> 35 #include <sys/rtprio.h> 36 #include <sys/stat.h> 37 #include <sys/time.h> 38 #include <sys/watchdog.h> 39 40 #include <err.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <libutil.h> 44 #include <math.h> 45 #include <paths.h> 46 #include <signal.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include <sysexits.h> 51 #include <unistd.h> 52 53 static void parseargs(int, char *[]); 54 static void sighandler(int); 55 static void watchdog_loop(void); 56 static int watchdog_init(void); 57 static int watchdog_onoff(int onoff); 58 static int watchdog_patpat(u_int timeout); 59 static void usage(void); 60 61 static int debugging = 0; 62 static int end_program = 0; 63 static const char *pidfile = _PATH_VARRUN "watchdogd.pid"; 64 static u_int timeout = WD_TO_16SEC; 65 static u_int passive = 0; 66 static int is_daemon = 0; 67 static int fd = -1; 68 static int nap = 1; 69 static char *test_cmd = NULL; 70 71 /* 72 * Periodically pat the watchdog, preventing it from firing. 73 */ 74 int 75 main(int argc, char *argv[]) 76 { 77 struct rtprio rtp; 78 struct pidfh *pfh; 79 pid_t otherpid; 80 81 if (getuid() != 0) 82 errx(EX_SOFTWARE, "not super user"); 83 84 parseargs(argc, argv); 85 86 rtp.type = RTP_PRIO_REALTIME; 87 rtp.prio = 0; 88 if (rtprio(RTP_SET, 0, &rtp) == -1) 89 err(EX_OSERR, "rtprio"); 90 91 if (watchdog_init() == -1) 92 errx(EX_SOFTWARE, "unable to initialize watchdog"); 93 94 if (is_daemon) { 95 if (watchdog_onoff(1) == -1) 96 err(EX_OSERR, "patting the dog"); 97 98 pfh = pidfile_open(pidfile, 0600, &otherpid); 99 if (pfh == NULL) { 100 if (errno == EEXIST) { 101 errx(EX_SOFTWARE, "%s already running, pid: %d", 102 getprogname(), otherpid); 103 } 104 warn("Cannot open or create pidfile"); 105 } 106 107 if (debugging == 0 && daemon(0, 0) == -1) { 108 watchdog_onoff(0); 109 pidfile_remove(pfh); 110 err(EX_OSERR, "daemon"); 111 } 112 113 signal(SIGHUP, SIG_IGN); 114 signal(SIGINT, sighandler); 115 signal(SIGTERM, sighandler); 116 117 pidfile_write(pfh); 118 119 watchdog_loop(); 120 121 /* exiting */ 122 pidfile_remove(pfh); 123 return (EX_OK); 124 } else { 125 if (passive) 126 timeout |= WD_PASSIVE; 127 else 128 timeout |= WD_ACTIVE; 129 if (watchdog_patpat(timeout) < 0) 130 err(EX_OSERR, "patting the dog"); 131 return (EX_OK); 132 } 133 } 134 135 /* 136 * Catch signals and begin shutdown process. 137 */ 138 static void 139 sighandler(int signum) 140 { 141 142 if (signum == SIGINT || signum == SIGTERM) 143 end_program = 1; 144 } 145 146 /* 147 * Open the watchdog device. 148 */ 149 static int 150 watchdog_init(void) 151 { 152 153 fd = open("/dev/" _PATH_WATCHDOG, O_RDWR); 154 if (fd >= 0) 155 return (0); 156 warn("Could not open watchdog device"); 157 return (-1); 158 } 159 160 /* 161 * Main program loop which is iterated every second. 162 */ 163 static void 164 watchdog_loop(void) 165 { 166 struct stat sb; 167 int failed; 168 169 while (end_program != 2) { 170 failed = 0; 171 172 if (test_cmd != NULL) 173 failed = system(test_cmd); 174 else 175 failed = stat("/etc", &sb); 176 177 if (failed == 0) 178 watchdog_patpat(timeout|WD_ACTIVE); 179 sleep(nap); 180 181 if (end_program != 0) { 182 if (watchdog_onoff(0) == 0) { 183 end_program = 2; 184 } else { 185 warnx("Could not stop the watchdog, not exitting"); 186 end_program = 0; 187 } 188 } 189 } 190 } 191 192 /* 193 * Reset the watchdog timer. This function must be called periodically 194 * to keep the watchdog from firing. 195 */ 196 static int 197 watchdog_patpat(u_int t) 198 { 199 200 return ioctl(fd, WDIOCPATPAT, &t); 201 } 202 203 /* 204 * Toggle the kernel's watchdog. This routine is used to enable and 205 * disable the watchdog. 206 */ 207 static int 208 watchdog_onoff(int onoff) 209 { 210 211 if (onoff) 212 return watchdog_patpat((timeout|WD_ACTIVE)); 213 else 214 return watchdog_patpat(0); 215 } 216 217 /* 218 * Tell user how to use the program. 219 */ 220 static void 221 usage(void) 222 { 223 if (is_daemon) 224 fprintf(stderr, "usage: watchdogd [-d] [-e cmd] [-I file] [-s sleep] [-t timeout]\n"); 225 else 226 fprintf(stderr, "usage: watchdog [-d] [-t timeout]\n"); 227 exit(EX_USAGE); 228 } 229 230 /* 231 * Handle the few command line arguments supported. 232 */ 233 static void 234 parseargs(int argc, char *argv[]) 235 { 236 int c; 237 char *p; 238 double a; 239 240 c = strlen(argv[0]); 241 if (argv[0][c - 1] == 'd') 242 is_daemon = 1; 243 while ((c = getopt(argc, argv, 244 is_daemon ? "I:de:s:t:?" : "dt:?")) != -1) { 245 switch (c) { 246 case 'I': 247 pidfile = optarg; 248 break; 249 case 'd': 250 debugging = 1; 251 break; 252 case 'e': 253 test_cmd = strdup(optarg); 254 break; 255 #ifdef notyet 256 case 'p': 257 passive = 1; 258 break; 259 #endif 260 case 's': 261 p = NULL; 262 errno = 0; 263 nap = strtol(optarg, &p, 0); 264 if ((p != NULL && *p != '\0') || errno != 0) 265 errx(EX_USAGE, "-s argument is not a number"); 266 break; 267 case 't': 268 p = NULL; 269 errno = 0; 270 a = strtod(optarg, &p); 271 if ((p != NULL && *p != '\0') || errno != 0) 272 errx(EX_USAGE, "-t argument is not a number"); 273 if (a < 0) 274 errx(EX_USAGE, "-t argument must be positive"); 275 if (a == 0) 276 timeout = WD_TO_NEVER; 277 else 278 timeout = 1.0 + log(a * 1e9) / log(2.0); 279 if (debugging) 280 printf("Timeout is 2^%d nanoseconds\n", 281 timeout); 282 break; 283 case '?': 284 default: 285 usage(); 286 /* NOTREACHED */ 287 } 288 } 289 if (argc != optind) 290 errx(EX_USAGE, "extra arguments."); 291 if (is_daemon && timeout < WD_TO_1SEC) 292 errx(EX_USAGE, "-t argument is less than one second."); 293 } 294