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/mman.h> 35 #include <sys/param.h> 36 #include <sys/rtprio.h> 37 #include <sys/stat.h> 38 #include <sys/time.h> 39 #include <sys/watchdog.h> 40 41 #include <err.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <libutil.h> 45 #include <math.h> 46 #include <paths.h> 47 #include <signal.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <strings.h> 52 #include <sysexits.h> 53 #include <unistd.h> 54 55 static void parseargs(int, char *[]); 56 static void sighandler(int); 57 static void watchdog_loop(void); 58 static int watchdog_init(void); 59 static int watchdog_onoff(int onoff); 60 static int watchdog_patpat(u_int timeout); 61 static void usage(void); 62 63 static int debugging = 0; 64 static int end_program = 0; 65 static const char *pidfile = _PATH_VARRUN "watchdogd.pid"; 66 static u_int timeout = WD_TO_16SEC; 67 static u_int passive = 0; 68 static int is_daemon = 0; 69 static int fd = -1; 70 static int nap = 1; 71 static 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 err(EX_OSERR, "patting the dog"); 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 if (madvise(0, 0, MADV_PROTECT) != 0) 121 warn("madvise failed"); 122 if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0) 123 warn("mlockall failed"); 124 125 watchdog_loop(); 126 127 /* exiting */ 128 pidfile_remove(pfh); 129 return (EX_OK); 130 } else { 131 if (passive) 132 timeout |= WD_PASSIVE; 133 else 134 timeout |= WD_ACTIVE; 135 if (watchdog_patpat(timeout) < 0) 136 err(EX_OSERR, "patting the dog"); 137 return (EX_OK); 138 } 139 } 140 141 /* 142 * Catch signals and begin shutdown process. 143 */ 144 static void 145 sighandler(int signum) 146 { 147 148 if (signum == SIGINT || signum == SIGTERM) 149 end_program = 1; 150 } 151 152 /* 153 * Open the watchdog device. 154 */ 155 static int 156 watchdog_init(void) 157 { 158 159 fd = open("/dev/" _PATH_WATCHDOG, O_RDWR); 160 if (fd >= 0) 161 return (0); 162 warn("Could not open watchdog device"); 163 return (-1); 164 } 165 166 /* 167 * Main program loop which is iterated every second. 168 */ 169 static void 170 watchdog_loop(void) 171 { 172 struct stat sb; 173 int failed; 174 175 while (end_program != 2) { 176 failed = 0; 177 178 if (test_cmd != NULL) 179 failed = system(test_cmd); 180 else 181 failed = stat("/etc", &sb); 182 183 if (failed == 0) 184 watchdog_patpat(timeout|WD_ACTIVE); 185 sleep(nap); 186 187 if (end_program != 0) { 188 if (watchdog_onoff(0) == 0) { 189 end_program = 2; 190 } else { 191 warnx("Could not stop the watchdog, not exitting"); 192 end_program = 0; 193 } 194 } 195 } 196 } 197 198 /* 199 * Reset the watchdog timer. This function must be called periodically 200 * to keep the watchdog from firing. 201 */ 202 static int 203 watchdog_patpat(u_int t) 204 { 205 206 return ioctl(fd, WDIOCPATPAT, &t); 207 } 208 209 /* 210 * Toggle the kernel's watchdog. This routine is used to enable and 211 * disable the watchdog. 212 */ 213 static int 214 watchdog_onoff(int onoff) 215 { 216 217 if (onoff) 218 return watchdog_patpat((timeout|WD_ACTIVE)); 219 else 220 return watchdog_patpat(0); 221 } 222 223 /* 224 * Tell user how to use the program. 225 */ 226 static void 227 usage(void) 228 { 229 if (is_daemon) 230 fprintf(stderr, "usage: watchdogd [-d] [-e cmd] [-I file] [-s sleep] [-t timeout]\n"); 231 else 232 fprintf(stderr, "usage: watchdog [-d] [-t timeout]\n"); 233 exit(EX_USAGE); 234 } 235 236 /* 237 * Handle the few command line arguments supported. 238 */ 239 static void 240 parseargs(int argc, char *argv[]) 241 { 242 int c; 243 char *p; 244 double a; 245 246 c = strlen(argv[0]); 247 if (argv[0][c - 1] == 'd') 248 is_daemon = 1; 249 while ((c = getopt(argc, argv, 250 is_daemon ? "I:de:s:t:?" : "dt:?")) != -1) { 251 switch (c) { 252 case 'I': 253 pidfile = optarg; 254 break; 255 case 'd': 256 debugging = 1; 257 break; 258 case 'e': 259 test_cmd = strdup(optarg); 260 break; 261 #ifdef notyet 262 case 'p': 263 passive = 1; 264 break; 265 #endif 266 case 's': 267 p = NULL; 268 errno = 0; 269 nap = strtol(optarg, &p, 0); 270 if ((p != NULL && *p != '\0') || errno != 0) 271 errx(EX_USAGE, "-s argument is not a number"); 272 break; 273 case 't': 274 p = NULL; 275 errno = 0; 276 a = strtod(optarg, &p); 277 if ((p != NULL && *p != '\0') || errno != 0) 278 errx(EX_USAGE, "-t argument is not a number"); 279 if (a < 0) 280 errx(EX_USAGE, "-t argument must be positive"); 281 if (a == 0) 282 timeout = WD_TO_NEVER; 283 else 284 timeout = flsll(a * 1e9); 285 if (debugging) 286 printf("Timeout is 2^%d nanoseconds\n", 287 timeout); 288 break; 289 case '?': 290 default: 291 usage(); 292 /* NOTREACHED */ 293 } 294 } 295 if (argc != optind) 296 errx(EX_USAGE, "extra arguments."); 297 if (is_daemon && timeout < WD_TO_1SEC) 298 errx(EX_USAGE, "-t argument is less than one second."); 299 } 300