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 int debugging = 0; 62 int end_program = 0; 63 const char *pidfile = _PATH_VARRUN "watchdogd.pid"; 64 int reset_mib[3]; 65 size_t reset_miblen = 3; 66 u_int timeout = WD_TO_16SEC; 67 u_int passive = 0; 68 int is_daemon = 0; 69 int fd = -1; 70 int nap = 1; 71 char *test_cmd = NULL; 72 73 /* 74 * Periodically pat the watchdog, preventing it from firing. 75 */ 76 int 77 main(int argc, char *argv[]) 78 { 79 struct rtprio rtp; 80 struct pidfh *pfh; 81 pid_t otherpid; 82 83 if (getuid() != 0) 84 errx(EX_SOFTWARE, "not super user"); 85 86 parseargs(argc, argv); 87 88 rtp.type = RTP_PRIO_REALTIME; 89 rtp.prio = 0; 90 if (rtprio(RTP_SET, 0, &rtp) == -1) 91 err(EX_OSERR, "rtprio"); 92 93 if (watchdog_init() == -1) 94 errx(EX_SOFTWARE, "unable to initialize watchdog"); 95 96 if (is_daemon) { 97 if (watchdog_onoff(1) == -1) 98 exit(EX_SOFTWARE); 99 100 pfh = pidfile_open(pidfile, 0600, &otherpid); 101 if (pfh == NULL) { 102 if (errno == EEXIST) { 103 errx(EX_SOFTWARE, "%s already running, pid: %d", 104 getprogname(), otherpid); 105 } 106 warn("Cannot open or create pidfile"); 107 } 108 109 if (debugging == 0 && daemon(0, 0) == -1) { 110 watchdog_onoff(0); 111 pidfile_remove(pfh); 112 err(EX_OSERR, "daemon"); 113 } 114 115 signal(SIGHUP, SIG_IGN); 116 signal(SIGINT, sighandler); 117 signal(SIGTERM, sighandler); 118 119 pidfile_write(pfh); 120 121 watchdog_loop(); 122 123 /* exiting */ 124 pidfile_remove(pfh); 125 return (EX_OK); 126 } else { 127 if (passive) 128 timeout |= WD_PASSIVE; 129 else 130 timeout |= WD_ACTIVE; 131 if (watchdog_patpat(timeout) < 0) 132 err(EX_OSERR, "patting the dog"); 133 return (EX_OK); 134 } 135 } 136 137 /* 138 * Catch signals and begin shutdown process. 139 */ 140 static void 141 sighandler(int signum) 142 { 143 144 if (signum == SIGINT || signum == SIGTERM) 145 end_program = 1; 146 } 147 148 /* 149 * Open the watchdog device. 150 */ 151 static int 152 watchdog_init() 153 { 154 155 fd = open("/dev/" _PATH_WATCHDOG, O_RDWR); 156 if (fd >= 0) 157 return (0); 158 warn("Could not open watchdog device"); 159 return (-1); 160 } 161 162 /* 163 * Main program loop which is iterated every second. 164 */ 165 static void 166 watchdog_loop(void) 167 { 168 struct stat sb; 169 int failed; 170 171 while (end_program != 2) { 172 failed = 0; 173 174 if (test_cmd != NULL) 175 failed = system(test_cmd); 176 else 177 failed = stat("/etc", &sb); 178 179 if (failed == 0) 180 watchdog_patpat(timeout|WD_ACTIVE); 181 sleep(nap); 182 183 if (end_program != 0) { 184 if (watchdog_onoff(0) == 0) { 185 end_program = 2; 186 } else { 187 warnx("Could not stop the watchdog, not exitting"); 188 end_program = 0; 189 } 190 } 191 } 192 } 193 194 /* 195 * Reset the watchdog timer. This function must be called periodically 196 * to keep the watchdog from firing. 197 */ 198 int 199 watchdog_patpat(u_int t) 200 { 201 202 return ioctl(fd, WDIOCPATPAT, &t); 203 } 204 205 /* 206 * Toggle the kernel's watchdog. This routine is used to enable and 207 * disable the watchdog. 208 */ 209 static int 210 watchdog_onoff(int onoff) 211 { 212 213 if (onoff) 214 return watchdog_patpat((timeout|WD_ACTIVE)); 215 else 216 return watchdog_patpat(0); 217 } 218 219 /* 220 * Tell user how to use the program. 221 */ 222 static void 223 usage() 224 { 225 if (is_daemon) 226 fprintf(stderr, "usage: watchdogd [-d] [-e cmd] [-I file] [-s sleep] [-t timeout]\n"); 227 else 228 fprintf(stderr, "usage: watchdog [-d] [-t timeout]\n"); 229 exit(EX_USAGE); 230 } 231 232 /* 233 * Handle the few command line arguments supported. 234 */ 235 static void 236 parseargs(int argc, char *argv[]) 237 { 238 int c; 239 char *p; 240 double a; 241 242 c = strlen(argv[0]); 243 if (argv[0][c - 1] == 'd') 244 is_daemon = 1; 245 while ((c = getopt(argc, argv, 246 is_daemon ? "I:de:s:t:?" : "dt:?")) != -1) { 247 switch (c) { 248 case 'I': 249 pidfile = optarg; 250 break; 251 case 'd': 252 debugging = 1; 253 break; 254 case 'e': 255 test_cmd = strdup(optarg); 256 break; 257 #ifdef notyet 258 case 'p': 259 passive = 1; 260 break; 261 #endif 262 case 's': 263 p = NULL; 264 errno = 0; 265 nap = strtol(optarg, &p, 0); 266 if ((p != NULL && *p != '\0') || errno != 0) 267 errx(EX_USAGE, "-s argument is not a number"); 268 break; 269 case 't': 270 p = NULL; 271 errno = 0; 272 a = strtod(optarg, &p); 273 if ((p != NULL && *p != '\0') || errno != 0) 274 errx(EX_USAGE, "-t argument is not a number"); 275 if (a < 0) 276 errx(EX_USAGE, "-t argument must be positive"); 277 if (a == 0) 278 timeout = WD_TO_NEVER; 279 else 280 timeout = 1.0 + log(a * 1e9) / log(2.0); 281 if (debugging) 282 printf("Timeout is 2^%d nanoseconds\n", 283 timeout); 284 break; 285 case '?': 286 default: 287 usage(); 288 /* NOTREACHED */ 289 } 290 } 291 if (argc != optind) 292 errx(EX_USAGE, "extra arguments."); 293 if (is_daemon && timeout < WD_TO_1SEC) 294 errx(EX_USAGE, "-t argument is less than one second."); 295 } 296