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(void); 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 watchdog_onoff(0); 125 pidfile_remove(pfh); 126 return (EX_OK); 127 } else { 128 if (passive) 129 timeout |= WD_PASSIVE; 130 else 131 timeout |= WD_ACTIVE; 132 if (watchdog_patpat() < 0) 133 err(EX_OSERR, "patting the dog"); 134 return (EX_OK); 135 } 136 } 137 138 /* 139 * Catch signals and begin shutdown process. 140 */ 141 static void 142 sighandler(int signum) 143 { 144 145 if (signum == SIGINT || signum == SIGTERM) 146 end_program = 1; 147 } 148 149 /* 150 * Open the watchdog device. 151 */ 152 static int 153 watchdog_init() 154 { 155 156 fd = open("/dev/" _PATH_WATCHDOG, O_RDWR); 157 if (fd >= 0) 158 return (0); 159 warn("Could not open watchdog device"); 160 return (-1); 161 } 162 163 /* 164 * Main program loop which is iterated every second. 165 */ 166 static void 167 watchdog_loop(void) 168 { 169 struct stat sb; 170 int failed; 171 172 while (end_program == 0) { 173 failed = 0; 174 175 if (test_cmd != NULL) 176 failed = system(test_cmd); 177 else 178 failed = stat("/etc", &sb); 179 180 if (failed == 0) 181 watchdog_patpat(); 182 sleep(nap); 183 } 184 } 185 186 /* 187 * Reset the watchdog timer. This function must be called periodically 188 * to keep the watchdog from firing. 189 */ 190 int 191 watchdog_patpat(void) 192 { 193 194 return ioctl(fd, WDIOCPATPAT, &timeout); 195 } 196 197 /* 198 * Toggle the kernel's watchdog. This routine is used to enable and 199 * disable the watchdog. 200 */ 201 static int 202 watchdog_onoff(int onoff) 203 { 204 205 if (onoff) 206 timeout |= WD_ACTIVE; 207 else 208 timeout &= ~WD_ACTIVE; 209 return watchdog_patpat(); 210 } 211 212 /* 213 * Tell user how to use the program. 214 */ 215 static void 216 usage() 217 { 218 if (is_daemon) 219 fprintf(stderr, "usage: watchdogd [-d] [-e cmd] [-I file]\n"); 220 else 221 fprintf(stderr, "usage: watchdog [-d] [-t timeout]\n"); 222 exit(EX_USAGE); 223 } 224 225 /* 226 * Handle the few command line arguments supported. 227 */ 228 static void 229 parseargs(int argc, char *argv[]) 230 { 231 int c; 232 char *p; 233 double a; 234 235 c = strlen(argv[0]); 236 if (argv[0][c - 1] == 'd') 237 is_daemon = 1; 238 while ((c = getopt(argc, argv, 239 is_daemon ? "I:de:s:t:?" : "dt:?")) != -1) { 240 switch (c) { 241 case 'I': 242 pidfile = optarg; 243 break; 244 case 'd': 245 debugging = 1; 246 break; 247 case 'e': 248 test_cmd = strdup(optarg); 249 break; 250 #ifdef notyet 251 case 'p': 252 passive = 1; 253 break; 254 #endif 255 case 's': 256 p = NULL; 257 errno = 0; 258 nap = strtol(optarg, &p, 0); 259 if ((p != NULL && *p != '\0') || errno != 0) 260 errx(EX_USAGE, "-s argument is not a number"); 261 break; 262 case 't': 263 p = NULL; 264 errno = 0; 265 a = strtod(optarg, &p); 266 if ((p != NULL && *p != '\0') || errno != 0) 267 errx(EX_USAGE, "-t argument is not a number"); 268 if (a < 0) 269 errx(EX_USAGE, "-t argument must be positive"); 270 if (a == 0) 271 timeout = WD_TO_NEVER; 272 else 273 timeout = 1.0 + log(a * 1e9) / log(2.0); 274 if (debugging) 275 printf("Timeout is 2^%d nanoseconds\n", 276 timeout); 277 break; 278 case '?': 279 default: 280 usage(); 281 /* NOTREACHED */ 282 } 283 } 284 if (argc != optind) 285 errx(EX_USAGE, "extra arguments."); 286 if (is_daemon && timeout < WD_TO_1SEC) 287 errx(EX_USAGE, "-t argument is less than one second."); 288 } 289