1 /* 2 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org> 3 * Copyright (C) 2013 John Crispin <blogic@openwrt.org> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU Lesser General Public License version 2.1 7 * as published by the Free Software Foundation 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/watchdog.h> 16 17 #include <sys/ioctl.h> 18 #include <sys/types.h> 19 #include <sys/stat.h> 20 #include <fcntl.h> 21 22 #include <unistd.h> 23 24 #include <libubox/uloop.h> 25 26 #include "procd.h" 27 #include "watchdog.h" 28 29 #define WDT_PATH "/dev/watchdog" 30 31 static struct uloop_timeout wdt_timeout; 32 static int wdt_fd = -1; 33 static int wdt_drv_timeout = 30; 34 static int wdt_frequency = 5; 35 static bool wdt_magicclose = false; 36 37 void watchdog_ping(void) 38 { 39 DEBUG(4, "Ping\n"); 40 if (wdt_fd >= 0 && write(wdt_fd, "X", 1) < 0) 41 ERROR("WDT failed to write: %m\n"); 42 } 43 44 static void watchdog_timeout_cb(struct uloop_timeout *t) 45 { 46 watchdog_ping(); 47 uloop_timeout_set(t, wdt_frequency * 1000); 48 } 49 50 static int watchdog_open(bool cloexec) 51 { 52 char *env = getenv("WDTFD"); 53 54 if (wdt_fd >= 0) 55 return wdt_fd; 56 57 if (env) { 58 DEBUG(2, "Watchdog handover: fd=%s\n", env); 59 wdt_fd = atoi(env); 60 unsetenv("WDTFD"); 61 } else { 62 wdt_fd = open(WDT_PATH, O_WRONLY); 63 } 64 65 if (wdt_fd < 0) 66 return wdt_fd; 67 68 if (cloexec) 69 fcntl(wdt_fd, F_SETFD, fcntl(wdt_fd, F_GETFD) | FD_CLOEXEC); 70 71 return wdt_fd; 72 } 73 74 static void watchdog_close(void) 75 { 76 if (wdt_fd < 0) 77 return; 78 79 if (write(wdt_fd, "V", 1) < 0) 80 ERROR("WDT failed to write release: %m\n"); 81 82 if (close(wdt_fd) == -1) 83 ERROR("WDT failed to close watchdog: %m\n"); 84 85 wdt_fd = -1; 86 } 87 88 static int watchdog_set_drv_timeout(void) 89 { 90 if (wdt_fd < 0) 91 return -1; 92 93 return ioctl(wdt_fd, WDIOC_SETTIMEOUT, &wdt_drv_timeout); 94 } 95 96 void watchdog_set_magicclose(bool val) 97 { 98 wdt_magicclose = val; 99 } 100 101 bool watchdog_get_magicclose(void) 102 { 103 return wdt_magicclose; 104 } 105 106 void watchdog_set_stopped(bool val) 107 { 108 if (val) { 109 uloop_timeout_cancel(&wdt_timeout); 110 111 if (wdt_magicclose) 112 watchdog_close(); 113 } 114 else { 115 watchdog_open(true); 116 watchdog_set_drv_timeout(); 117 watchdog_timeout_cb(&wdt_timeout); 118 } 119 } 120 121 bool watchdog_get_stopped(void) 122 { 123 return !wdt_timeout.pending; 124 } 125 126 int watchdog_timeout(int timeout) 127 { 128 if (timeout) { 129 DEBUG(4, "Set watchdog timeout: %ds\n", timeout); 130 wdt_drv_timeout = timeout; 131 132 if (wdt_fd >= 0) 133 watchdog_set_drv_timeout(); 134 } 135 136 return wdt_drv_timeout; 137 } 138 139 int watchdog_frequency(int frequency) 140 { 141 if (frequency) { 142 DEBUG(4, "Set watchdog frequency: %ds\n", frequency); 143 wdt_frequency = frequency; 144 } 145 146 return wdt_frequency; 147 } 148 149 char* watchdog_fd(void) 150 { 151 static char fd_buf[12]; 152 153 if (wdt_fd < 0) 154 return NULL; 155 156 snprintf(fd_buf, sizeof(fd_buf), "%d", wdt_fd); 157 158 return fd_buf; 159 } 160 161 void watchdog_init(int preinit) 162 { 163 wdt_timeout.cb = watchdog_timeout_cb; 164 165 if (watchdog_open(!preinit) < 0) 166 return; 167 168 LOG("- watchdog -\n"); 169 watchdog_set_drv_timeout(); 170 watchdog_timeout_cb(&wdt_timeout); 171 172 DEBUG(4, "Opened watchdog with timeout %ds\n", watchdog_timeout(0)); 173 } 174 175 176 void watchdog_set_cloexec(bool val) 177 { 178 if (wdt_fd < 0) 179 return; 180 181 int flags = fcntl(wdt_fd, F_GETFD); 182 if (val) 183 flags |= FD_CLOEXEC; 184 else 185 flags &= ~FD_CLOEXEC; 186 fcntl(wdt_fd, F_SETFD, flags); 187 } 188
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