/* * Copyright (c) 2010-2012 Red Hat, Inc. * * All rights reserved. * * Author: Angus Salkeld * * This software licensed under BSD license, the text of which follows: * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * - Neither the name of the MontaVista Software, Inc. nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fsm.h" #include "service.h" typedef enum { WD_RESOURCE_GOOD, WD_RESOURCE_FAILED, WD_RESOURCE_STATE_UNKNOWN, WD_RESOURCE_NOT_MONITORED } wd_resource_state_t; struct resource { char res_path[ICMAP_KEYNAME_MAXLEN]; char *recovery; char name[CS_MAX_NAME_LENGTH]; time_t last_updated; struct cs_fsm fsm; corosync_timer_handle_t check_timer; uint64_t check_timeout; icmap_track_t icmap_track; }; LOGSYS_DECLARE_SUBSYS("WD"); /* * Service Interfaces required by service_message_handler struct */ static char *wd_exec_init_fn (struct corosync_api_v1 *corosync_api); static int wd_exec_exit_fn (void); static void wd_resource_check_fn (void* resource_ref); static struct corosync_api_v1 *api; #define WD_DEFAULT_TIMEOUT_SEC 6 #define WD_DEFAULT_TIMEOUT_MS (WD_DEFAULT_TIMEOUT_SEC * CS_TIME_MS_IN_SEC) #define WD_MIN_TIMEOUT_MS 500 #define WD_MAX_TIMEOUT_MS (120 * CS_TIME_MS_IN_SEC) static uint32_t watchdog_timeout = WD_DEFAULT_TIMEOUT_SEC; static uint64_t tickle_timeout = (WD_DEFAULT_TIMEOUT_MS / 2); static int dog = -1; static corosync_timer_handle_t wd_timer; static int watchdog_ok = 1; static char *watchdog_device = NULL; struct corosync_service_engine wd_service_engine = { .name = "corosync watchdog service", .id = WD_SERVICE, .priority = 1, .private_data_size = 0, .flow_control = CS_LIB_FLOW_CONTROL_NOT_REQUIRED, .lib_init_fn = NULL, .lib_exit_fn = NULL, .lib_engine = NULL, .lib_engine_count = 0, .exec_engine = NULL, .exec_engine_count = 0, .confchg_fn = NULL, .exec_init_fn = wd_exec_init_fn, .exec_exit_fn = wd_exec_exit_fn, .exec_dump_fn = NULL }; static QB_LIST_DECLARE (confchg_notify); /* * F S M */ static void wd_config_changed (struct cs_fsm* fsm, int32_t event, void * data); static void wd_resource_failed (struct cs_fsm* fsm, int32_t event, void * data); enum wd_resource_state { WD_S_RUNNING, WD_S_FAILED, WD_S_STOPPED }; enum wd_resource_event { WD_E_FAILURE, WD_E_CONFIG_CHANGED }; const char * wd_running_str = "running"; const char * wd_failed_str = "failed"; const char * wd_failure_str = "failure"; const char * wd_stopped_str = "stopped"; const char * wd_config_changed_str = "config_changed"; struct cs_fsm_entry wd_fsm_table[] = { { WD_S_STOPPED, WD_E_CONFIG_CHANGED, wd_config_changed, {WD_S_STOPPED, WD_S_RUNNING, -1} }, { WD_S_STOPPED, WD_E_FAILURE, NULL, {-1} }, { WD_S_RUNNING, WD_E_CONFIG_CHANGED, wd_config_changed, {WD_S_RUNNING, WD_S_STOPPED, -1} }, { WD_S_RUNNING, WD_E_FAILURE, wd_resource_failed, {WD_S_FAILED, -1} }, { WD_S_FAILED, WD_E_CONFIG_CHANGED, wd_config_changed, {WD_S_RUNNING, WD_S_STOPPED, -1} }, { WD_S_FAILED, WD_E_FAILURE, NULL, {-1} }, }; struct corosync_service_engine *wd_get_service_engine_ver0 (void) { return (&wd_service_engine); } static const char * wd_res_state_to_str(struct cs_fsm* fsm, int32_t state) { switch (state) { case WD_S_STOPPED: return wd_stopped_str; break; case WD_S_RUNNING: return wd_running_str; break; case WD_S_FAILED: return wd_failed_str; break; } return NULL; } static const char * wd_res_event_to_str(struct cs_fsm* fsm, int32_t event) { switch (event) { case WD_E_CONFIG_CHANGED: return wd_config_changed_str; break; case WD_E_FAILURE: return wd_failure_str; break; } return NULL; } static void wd_fsm_cb (struct cs_fsm *fsm, int cb_event, int32_t curr_state, int32_t next_state, int32_t fsm_event, void *data) { switch (cb_event) { case CS_FSM_CB_EVENT_PROCESS_NF: log_printf (LOGSYS_LEVEL_ERROR, "Fsm:%s could not find event \"%s\" in state \"%s\"", fsm->name, fsm->event_to_str(fsm, fsm_event), fsm->state_to_str(fsm, curr_state)); corosync_exit_error(COROSYNC_DONE_FATAL_ERR); break; case CS_FSM_CB_EVENT_STATE_SET: log_printf (LOGSYS_LEVEL_INFO, "Fsm:%s event \"%s\", state \"%s\" --> \"%s\"", fsm->name, fsm->event_to_str(fsm, fsm_event), fsm->state_to_str(fsm, fsm->table[fsm->curr_entry].curr_state), fsm->state_to_str(fsm, next_state)); break; case CS_FSM_CB_EVENT_STATE_SET_NF: log_printf (LOGSYS_LEVEL_CRIT, "Fsm:%s Can't change state from \"%s\" to \"%s\" (event was \"%s\")", fsm->name, fsm->state_to_str(fsm, fsm->table[fsm->curr_entry].curr_state), fsm->state_to_str(fsm, next_state), fsm->event_to_str(fsm, fsm_event)); corosync_exit_error(COROSYNC_DONE_FATAL_ERR); break; default: log_printf (LOGSYS_LEVEL_CRIT, "Fsm: Unknown callback event!"); corosync_exit_error(COROSYNC_DONE_FATAL_ERR); break; } } /* * returns (CS_TRUE == OK, CS_FALSE == failed) */ static int32_t wd_resource_state_is_ok (struct resource *ref) { char* state = NULL; uint64_t last_updated; uint64_t my_time; uint64_t allowed_period; char key_name[ICMAP_KEYNAME_MAXLEN]; if ((snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", ref->res_path, "last_updated") >= ICMAP_KEYNAME_MAXLEN) || (icmap_get_uint64(key_name, &last_updated) != CS_OK)) { /* key does not exist. */ return CS_FALSE; } if ((snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", ref->res_path, "state") >= ICMAP_KEYNAME_MAXLEN) || (icmap_get_string(key_name, &state) != CS_OK || strcmp(state, "disabled") == 0)) { /* key does not exist. */ if (state != NULL) free(state); return CS_FALSE; } if (last_updated == 0) { /* initial value */ free(state); return CS_TRUE; } my_time = cs_timestamp_get(); /* * Here we check that the monitor has written a timestamp within the poll_period * plus a grace factor of (0.5 * poll_period). */ allowed_period = (ref->check_timeout * MILLI_2_NANO_SECONDS * 3) / 2; if ((last_updated + allowed_period) < my_time) { log_printf (LOGSYS_LEVEL_ERROR, "last_updated %"PRIu64" ms too late, period:%"PRIu64".", (uint64_t)(my_time/MILLI_2_NANO_SECONDS - ((last_updated + allowed_period) / MILLI_2_NANO_SECONDS)), ref->check_timeout); free(state); return CS_FALSE; } if (strcmp (state, wd_failed_str) == 0) { free(state); return CS_FALSE; } free(state); return CS_TRUE; } static void wd_config_changed (struct cs_fsm* fsm, int32_t event, void * data) { char *state; uint64_t tmp_value; uint64_t next_timeout; struct resource *ref = (struct resource*)data; char key_name[ICMAP_KEYNAME_MAXLEN]; next_timeout = ref->check_timeout; if ((snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", ref->res_path, "poll_period") >= ICMAP_KEYNAME_MAXLEN) || (icmap_get_uint64(ref->res_path, &tmp_value) == CS_OK)) { if (tmp_value >= WD_MIN_TIMEOUT_MS && tmp_value <= WD_MAX_TIMEOUT_MS) { log_printf (LOGSYS_LEVEL_DEBUG, "poll_period changing from:%"PRIu64" to %"PRIu64".", ref->check_timeout, tmp_value); /* * To easy in the transition between poll_period's we are going * to make the first timeout the bigger of the new and old value. * This is to give the monitoring system time to adjust. */ next_timeout = CS_MAX(tmp_value, ref->check_timeout); ref->check_timeout = tmp_value; } else { log_printf (LOGSYS_LEVEL_WARNING, "Could NOT use poll_period:%"PRIu64" ms for resource %s", tmp_value, ref->name); } } if ((snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", ref->res_path, "recovery") >= ICMAP_KEYNAME_MAXLEN) || (icmap_get_string(key_name, &ref->recovery) != CS_OK)) { /* key does not exist. */ log_printf (LOGSYS_LEVEL_WARNING, "resource %s missing a recovery key.", ref->name); cs_fsm_state_set(&ref->fsm, WD_S_STOPPED, ref, wd_fsm_cb); return; } if ((snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", ref->res_path, "state") >= ICMAP_KEYNAME_MAXLEN) || (icmap_get_string(key_name, &state) != CS_OK)) { /* key does not exist. */ log_printf (LOGSYS_LEVEL_WARNING, "resource %s missing a state key.", ref->name); cs_fsm_state_set(&ref->fsm, WD_S_STOPPED, ref, wd_fsm_cb); return; } if (ref->check_timer) { api->timer_delete(ref->check_timer); ref->check_timer = 0; } if (strcmp(wd_stopped_str, state) == 0) { cs_fsm_state_set(&ref->fsm, WD_S_STOPPED, ref, wd_fsm_cb); } else { api->timer_add_duration(next_timeout * MILLI_2_NANO_SECONDS, ref, wd_resource_check_fn, &ref->check_timer); cs_fsm_state_set(&ref->fsm, WD_S_RUNNING, ref, wd_fsm_cb); } free(state); } static void wd_resource_failed (struct cs_fsm* fsm, int32_t event, void * data) { struct resource* ref = (struct resource*)data; if (ref->check_timer) { api->timer_delete(ref->check_timer); ref->check_timer = 0; } log_printf (LOGSYS_LEVEL_CRIT, "%s resource \"%s\" failed!", ref->recovery, (char*)ref->name); if (strcmp (ref->recovery, "watchdog") == 0 || strcmp (ref->recovery, "quit") == 0) { watchdog_ok = 0; } else if (strcmp (ref->recovery, "reboot") == 0) { reboot(RB_AUTOBOOT); } else if (strcmp (ref->recovery, "shutdown") == 0) { reboot(RB_POWER_OFF); } cs_fsm_state_set(fsm, WD_S_FAILED, data, wd_fsm_cb); } static void wd_key_changed( int32_t event, const char *key_name, struct icmap_notify_value new_val, struct icmap_notify_value old_val, void *user_data) { struct resource* ref = (struct resource*)user_data; char *last_key_part; if (ref == NULL) { return ; } last_key_part = strrchr(key_name, '.'); if (last_key_part == NULL) { return ; } last_key_part++; if (event == ICMAP_TRACK_ADD || event == ICMAP_TRACK_MODIFY) { if (strcmp(last_key_part, "last_updated") == 0 || strcmp(last_key_part, "current") == 0) { return; } cs_fsm_process(&ref->fsm, WD_E_CONFIG_CHANGED, ref, wd_fsm_cb); } if (event == ICMAP_TRACK_DELETE && ref != NULL) { if (strcmp(last_key_part, "state") != 0) { return ; } log_printf (LOGSYS_LEVEL_WARNING, "resource \"%s\" deleted from cmap!", ref->name); api->timer_delete(ref->check_timer); ref->check_timer = 0; icmap_track_delete(ref->icmap_track); free(ref); } } static void wd_resource_check_fn (void* resource_ref) { struct resource* ref = (struct resource*)resource_ref; if (wd_resource_state_is_ok (ref) == CS_FALSE) { cs_fsm_process(&ref->fsm, WD_E_FAILURE, ref, wd_fsm_cb); return; } api->timer_add_duration(ref->check_timeout*MILLI_2_NANO_SECONDS, ref, wd_resource_check_fn, &ref->check_timer); } /* * return 0 - fully configured * return -1 - partially configured */ static int32_t wd_resource_create (char *res_path, char *res_name) { char *state; uint64_t tmp_value; struct resource *ref = calloc (1, sizeof (struct resource)); char key_name[ICMAP_KEYNAME_MAXLEN]; strcpy(ref->res_path, res_path); ref->check_timeout = WD_DEFAULT_TIMEOUT_MS; ref->check_timer = 0; strcpy(ref->name, res_name); ref->fsm.name = ref->name; ref->fsm.table = wd_fsm_table; ref->fsm.entries = sizeof(wd_fsm_table) / sizeof(struct cs_fsm_entry); ref->fsm.curr_entry = 0; ref->fsm.curr_state = WD_S_STOPPED; ref->fsm.state_to_str = wd_res_state_to_str; ref->fsm.event_to_str = wd_res_event_to_str; snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", res_path, "poll_period"); if (icmap_get_uint64(key_name, &tmp_value) != CS_OK) { icmap_set_uint64(key_name, ref->check_timeout); } else { if (tmp_value >= WD_MIN_TIMEOUT_MS && tmp_value <= WD_MAX_TIMEOUT_MS) { ref->check_timeout = tmp_value; } else { log_printf (LOGSYS_LEVEL_WARNING, "Could NOT use poll_period:%"PRIu64" ms for resource %s", tmp_value, ref->name); } } icmap_track_add(res_path, ICMAP_TRACK_ADD | ICMAP_TRACK_MODIFY | ICMAP_TRACK_DELETE | ICMAP_TRACK_PREFIX, wd_key_changed, ref, &ref->icmap_track); snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", res_path, "recovery"); if (icmap_get_string(key_name, &ref->recovery) != CS_OK) { /* key does not exist. */ log_printf (LOGSYS_LEVEL_WARNING, "resource %s missing a recovery key.", ref->name); return -1; } snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", res_path, "state"); if (icmap_get_string(key_name, &state) != CS_OK) { /* key does not exist. */ log_printf (LOGSYS_LEVEL_WARNING, "resource %s missing a state key.", ref->name); return -1; } snprintf(key_name, ICMAP_KEYNAME_MAXLEN, "%s%s", res_path, "last_updated"); if (icmap_get_uint64(key_name, &tmp_value) != CS_OK) { /* key does not exist. */ ref->last_updated = 0; } else { ref->last_updated = tmp_value; } /* * delay the first check to give the monitor time to start working. */ tmp_value = CS_MAX(ref->check_timeout * 2, WD_DEFAULT_TIMEOUT_MS); api->timer_add_duration(tmp_value * MILLI_2_NANO_SECONDS, ref, wd_resource_check_fn, &ref->check_timer); cs_fsm_state_set(&ref->fsm, WD_S_RUNNING, ref, wd_fsm_cb); return 0; } static void wd_tickle_fn (void* arg) { ENTER(); if (watchdog_ok) { if (dog > 0) { ioctl(dog, WDIOC_KEEPALIVE, &watchdog_ok); } api->timer_add_duration(tickle_timeout*MILLI_2_NANO_SECONDS, NULL, wd_tickle_fn, &wd_timer); } else { log_printf (LOGSYS_LEVEL_ALERT, "NOT tickling the watchdog!"); } } static void wd_resource_created_cb( int32_t event, const char *key_name, struct icmap_notify_value new_val, struct icmap_notify_value old_val, void *user_data) { char res_name[ICMAP_KEYNAME_MAXLEN]; char res_type[ICMAP_KEYNAME_MAXLEN]; char tmp_key[ICMAP_KEYNAME_MAXLEN]; int res; if (event != ICMAP_TRACK_ADD) { return ; } res = sscanf(key_name, "resources.%[^.].%[^.].%[^.]", res_type, res_name, tmp_key); if (res != 3) { return ; } if (strcmp(tmp_key, "state") != 0) { return ; } snprintf(tmp_key, ICMAP_KEYNAME_MAXLEN, "resources.%s.%s.", res_type, res_name); wd_resource_create (tmp_key, res_name); } static void wd_scan_resources (void) { int res_count = 0; icmap_track_t icmap_track = NULL; icmap_iter_t iter; const char *key_name; int res; char res_name[ICMAP_KEYNAME_MAXLEN]; char res_type[ICMAP_KEYNAME_MAXLEN]; char tmp_key[ICMAP_KEYNAME_MAXLEN]; ENTER(); iter = icmap_iter_init("resources."); while ((key_name = icmap_iter_next(iter, NULL, NULL)) != NULL) { res = sscanf(key_name, "resources.%[^.].%[^.].%[^.]", res_type, res_name, tmp_key); if (res != 3) { continue ; } if (strcmp(tmp_key, "state") != 0) { continue ; } snprintf(tmp_key, ICMAP_KEYNAME_MAXLEN, "resources.%s.%s.", res_type, res_name); if (wd_resource_create (tmp_key, res_name) == 0) { res_count++; } } icmap_iter_finalize(iter); icmap_track_add("resources.process.", ICMAP_TRACK_ADD | ICMAP_TRACK_PREFIX, wd_resource_created_cb, NULL, &icmap_track); icmap_track_add("resources.system.", ICMAP_TRACK_ADD | ICMAP_TRACK_PREFIX, wd_resource_created_cb, NULL, &icmap_track); if (res_count == 0) { log_printf (LOGSYS_LEVEL_INFO, "no resources configured."); } } static void watchdog_timeout_apply (uint32_t new) { struct watchdog_info ident; uint32_t original_timeout = 0; if (dog > 0) { ioctl(dog, WDIOC_GETTIMEOUT, &original_timeout); } if (new == original_timeout) { return; } watchdog_timeout = new; if (dog > 0) { ioctl(dog, WDIOC_GETSUPPORT, &ident); if (ident.options & WDIOF_SETTIMEOUT) { /* yay! the dog is trained. */ ioctl(dog, WDIOC_SETTIMEOUT, &watchdog_timeout); } ioctl(dog, WDIOC_GETTIMEOUT, &watchdog_timeout); } if (watchdog_timeout == new) { tickle_timeout = (watchdog_timeout * CS_TIME_MS_IN_SEC)/ 2; /* reset the tickle timer in case it was reduced. */ api->timer_delete (wd_timer); api->timer_add_duration(tickle_timeout*MILLI_2_NANO_SECONDS, NULL, wd_tickle_fn, &wd_timer); log_printf (LOGSYS_LEVEL_DEBUG, "The Watchdog timeout is %d seconds", watchdog_timeout); log_printf (LOGSYS_LEVEL_DEBUG, "The tickle timeout is %"PRIu64" ms", tickle_timeout); } else { log_printf (LOGSYS_LEVEL_WARNING, "Could not change the Watchdog timeout from %d to %d seconds", original_timeout, new); } } static int setup_watchdog(void) { struct watchdog_info ident; char *str; ENTER(); if (icmap_get_string("resources.watchdog_device", &str) == CS_OK) { if (str[0] == 0 || strcmp (str, "off") == 0) { log_printf (LOGSYS_LEVEL_WARNING, "Watchdog disabled by configuration"); free(str); dog = -1; return -1; } else { watchdog_device = str; } } else { log_printf (LOGSYS_LEVEL_WARNING, "Watchdog not enabled by configuration"); dog = -1; return -1; } if (access (watchdog_device, W_OK) != 0) { log_printf (LOGSYS_LEVEL_WARNING, "No watchdog %s, try modprobe ", watchdog_device); dog = -1; return -1; } /* here goes, lets hope they have "Magic Close" */ dog = open(watchdog_device, O_WRONLY); if (dog == -1) { log_printf (LOGSYS_LEVEL_WARNING, "Watchdog %s exists but couldn't be opened.", watchdog_device); dog = -1; return -1; } /* Right we have the dog. * Lets see what breed it is. */ ioctl(dog, WDIOC_GETSUPPORT, &ident); log_printf (LOGSYS_LEVEL_INFO, "Watchdog %s is now being tickled by corosync.", watchdog_device); log_printf (LOGSYS_LEVEL_DEBUG, "%s", ident.identity); watchdog_timeout_apply (watchdog_timeout); ioctl(dog, WDIOC_SETOPTIONS, WDIOS_ENABLECARD); return 0; } static void wd_top_level_key_changed( int32_t event, const char *key_name, struct icmap_notify_value new_val, struct icmap_notify_value old_val, void *user_data) { uint32_t tmp_value_32; ENTER(); if (icmap_get_uint32("resources.watchdog_timeout", &tmp_value_32) == CS_OK) { if (tmp_value_32 >= 2 && tmp_value_32 <= 120) { watchdog_timeout_apply (tmp_value_32); return; } } log_printf (LOGSYS_LEVEL_WARNING, "Set watchdog_timeout is out of range (2..120)."); icmap_set_uint32("resources.watchdog_timeout", watchdog_timeout); } static void watchdog_timeout_get_initial (void) { uint32_t tmp_value_32; icmap_track_t icmap_track = NULL; ENTER(); if (icmap_get_uint32("resources.watchdog_timeout", &tmp_value_32) != CS_OK) { watchdog_timeout_apply (WD_DEFAULT_TIMEOUT_SEC); icmap_set_uint32("resources.watchdog_timeout", watchdog_timeout); } else { if (tmp_value_32 >= 2 && tmp_value_32 <= 120) { watchdog_timeout_apply (tmp_value_32); } else { log_printf (LOGSYS_LEVEL_WARNING, "Set watchdog_timeout is out of range (2..120)."); log_printf (LOGSYS_LEVEL_INFO, "use default value %d seconds.", WD_DEFAULT_TIMEOUT_SEC); watchdog_timeout_apply (WD_DEFAULT_TIMEOUT_SEC); icmap_set_uint32("resources.watchdog_timeout", watchdog_timeout); } } icmap_track_add("resources.watchdog_timeout", ICMAP_TRACK_MODIFY, wd_top_level_key_changed, NULL, &icmap_track); } static char *wd_exec_init_fn (struct corosync_api_v1 *corosync_api) { ENTER(); api = corosync_api; watchdog_timeout_get_initial(); setup_watchdog(); wd_scan_resources(); return NULL; } static int wd_exec_exit_fn (void) { char magic = 'V'; ENTER(); if (dog > 0) { log_printf (LOGSYS_LEVEL_INFO, "magically closing the watchdog."); if (write (dog, &magic, 1) == -1) { log_printf (LOGSYS_LEVEL_ERROR, "failed to write %c to dog(%d).", magic, dog); } } return 0; }