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/*
* Copyright 2013-2020 the Pacemaker project contributors
*
* The version control history for this file may have further details.
*
* This source code is licensed under the GNU Lesser General Public License
* version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
*/
#include <crm_internal.h>
#include <sched.h>
#include <sys/ioctl.h>
#include <sys/reboot.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <dirent.h>
#include <signal.h>
#ifdef _POSIX_MEMLOCK
# include <sys/mman.h>
#endif
static pid_t sbd_pid = 0;
static void
sysrq_trigger(char t)
{
#if HAVE_PROCFS
FILE *procf;
// Root can always write here, regardless of kernel.sysrq value
procf = fopen("/proc/sysrq-trigger", "a");
if (!procf) {
crm_perror(LOG_WARNING, "Opening sysrq-trigger failed");
return;
}
crm_info("sysrq-trigger: %c", t);
fprintf(procf, "%c\n", t);
fclose(procf);
#endif // HAVE_PROCFS
return;
}
/*!
* \internal
* \brief Panic the local host (if root) or tell pacemakerd to do so
*/
static void
panic_local(void)
{
int rc = pcmk_ok;
uid_t uid = geteuid();
pid_t ppid = getppid();
if(uid != 0 && ppid > 1) {
/* We're a non-root pacemaker daemon (pacemaker-based,
* pacemaker-controld, pacemaker-schedulerd, pacemaker-attrd, etc.) with
* the original pacemakerd parent.
*
* Of these, only the controller is likely to be initiating resets.
*/
crm_emerg("Signaling parent %lld to panic", (long long) ppid);
crm_exit(CRM_EX_PANIC);
return;
} else if (uid != 0) {
#if HAVE_PROCFS
/*
* No permissions, and no pacemakerd parent to escalate to.
* Track down the new pacemakerd process and send a signal instead.
*/
union sigval signal_value;
memset(&signal_value, 0, sizeof(signal_value));
ppid = pcmk__procfs_pid_of("pacemakerd");
crm_emerg("Signaling pacemakerd[%lld] to panic", (long long) ppid);
if(ppid > 1 && sigqueue(ppid, SIGQUIT, signal_value) < 0) {
crm_perror(LOG_EMERG, "Cannot signal pacemakerd[%lld] to panic",
(long long) ppid);
}
#endif // HAVE_PROCFS
/* The best we can do now is die */
crm_exit(CRM_EX_PANIC);
return;
}
/* We're either pacemakerd, or a pacemaker daemon running as root */
if (pcmk__str_eq("crash", getenv("PCMK_panic_action"), pcmk__str_casei)) {
sysrq_trigger('c');
} else if (pcmk__str_eq("sync-crash", getenv("PCMK_panic_action"), pcmk__str_casei)) {
sync();
sysrq_trigger('c');
} else {
if (pcmk__str_eq("sync-reboot", getenv("PCMK_panic_action"), pcmk__str_casei)) {
sync();
}
sysrq_trigger('b');
}
/* reboot(RB_HALT_SYSTEM); rc = errno; */
reboot(RB_AUTOBOOT);
rc = errno;
crm_emerg("Reboot failed, escalating to parent %lld: %s " CRM_XS " rc=%d",
(long long) ppid, pcmk_rc_str(rc), rc);
if(ppid > 1) {
/* child daemon */
exit(CRM_EX_PANIC);
} else {
/* pacemakerd or orphan child */
exit(CRM_EX_FATAL);
}
}
/*!
* \internal
* \brief Tell sbd to kill the local host, then exit
*/
static void
panic_sbd(void)
{
union sigval signal_value;
pid_t ppid = getppid();
crm_emerg("Signaling sbd[%lld] to panic", (long long) sbd_pid);
memset(&signal_value, 0, sizeof(signal_value));
/* TODO: Arrange for a slightly less brutal option? */
if(sigqueue(sbd_pid, SIGKILL, signal_value) < 0) {
crm_perror(LOG_EMERG, "Cannot signal sbd[%lld] to terminate",
(long long) sbd_pid);
panic_local();
}
if(ppid > 1) {
/* child daemon */
exit(CRM_EX_PANIC);
} else {
/* pacemakerd or orphan child */
exit(CRM_EX_FATAL);
}
}
/*!
* \internal
* \brief Panic the local host
*
* Panic the local host either by sbd (if running), directly, or by asking
* pacemakerd. If trace logging this function, exit instead.
*
* \param[in] origin Function caller (for logging only)
*/
void
pcmk__panic(const char *origin)
{
static struct qb_log_callsite *panic_cs = NULL;
if (panic_cs == NULL) {
panic_cs = qb_log_callsite_get(__func__, __FILE__, "panic-delay",
LOG_TRACE, __LINE__, crm_trace_nonlog);
}
/* Ensure sbd_pid is set */
(void) pcmk__locate_sbd();
if (panic_cs && panic_cs->targets) {
/* getppid() == 1 means our original parent no longer exists */
crm_emerg("Shutting down instead of panicking the node "
CRM_XS " origin=%s sbd=%lld parent=%d",
origin, (long long) sbd_pid, getppid());
crm_exit(CRM_EX_FATAL);
return;
}
if(sbd_pid > 1) {
crm_emerg("Signaling sbd[%lld] to panic the system: %s",
(long long) sbd_pid, origin);
panic_sbd();
} else {
crm_emerg("Panicking the system directly: %s", origin);
panic_local();
}
}
/*!
* \internal
* \brief Return the process ID of sbd (or 0 if it is not running)
*/
pid_t
pcmk__locate_sbd(void)
{
char *pidfile = NULL;
char *sbd_path = NULL;
int rc;
if(sbd_pid > 1) {
return sbd_pid;
}
/* Look for the pid file */
pidfile = crm_strdup_printf(PCMK_RUN_DIR "/sbd.pid");
sbd_path = crm_strdup_printf("%s/sbd", SBIN_DIR);
/* Read the pid file */
rc = pcmk__pidfile_matches(pidfile, 0, sbd_path, &sbd_pid);
if (rc == pcmk_rc_ok) {
crm_trace("SBD detected at pid %lld (via PID file %s)",
(long long) sbd_pid, pidfile);
#if HAVE_PROCFS
} else {
/* Fall back to /proc for systems that support it */
sbd_pid = pcmk__procfs_pid_of("sbd");
crm_trace("SBD detected at pid %lld (via procfs)",
(long long) sbd_pid);
#endif // HAVE_PROCFS
}
if(sbd_pid < 0) {
sbd_pid = 0;
crm_trace("SBD not detected");
}
free(pidfile);
free(sbd_path);
return sbd_pid;
}
long
pcmk__get_sbd_timeout(void)
{
static long sbd_timeout = -2;
if (sbd_timeout == -2) {
sbd_timeout = crm_get_msec(getenv("SBD_WATCHDOG_TIMEOUT"));
}
return sbd_timeout;
}
bool
pcmk__get_sbd_sync_resource_startup(void)
{
static int sync_resource_startup = PCMK__SBD_SYNC_DEFAULT;
static bool checked_sync_resource_startup = false;
if (!checked_sync_resource_startup) {
const char *sync_env = getenv("SBD_SYNC_RESOURCE_STARTUP");
if (sync_env == NULL) {
crm_trace("Defaulting to %sstart-up synchronization with sbd",
(PCMK__SBD_SYNC_DEFAULT? "" : "no "));
} else if (crm_str_to_boolean(sync_env, &sync_resource_startup) < 0) {
crm_warn("Defaulting to %sstart-up synchronization with sbd "
"because environment value '%s' is invalid",
(PCMK__SBD_SYNC_DEFAULT? "" : "no "), sync_env);
}
checked_sync_resource_startup = true;
}
return sync_resource_startup != 0;
}
long
pcmk__auto_watchdog_timeout(void)
{
long sbd_timeout = pcmk__get_sbd_timeout();
return (sbd_timeout <= 0)? 0 : (2 * sbd_timeout);
}
bool
pcmk__valid_sbd_timeout(const char *value)
{
long st_timeout = value? crm_get_msec(value) : 0;
if (st_timeout < 0) {
st_timeout = pcmk__auto_watchdog_timeout();
crm_debug("Using calculated value %ld for stonith-watchdog-timeout (%s)",
st_timeout, value);
}
if (st_timeout == 0) {
crm_debug("Watchdog may be enabled but stonith-watchdog-timeout is disabled (%s)",
value? value : "default");
} else if (pcmk__locate_sbd() == 0) {
crm_emerg("Shutting down: stonith-watchdog-timeout configured (%s) "
"but SBD not active", (value? value : "auto"));
crm_exit(CRM_EX_FATAL);
return false;
} else {
long sbd_timeout = pcmk__get_sbd_timeout();
if (st_timeout < sbd_timeout) {
crm_emerg("Shutting down: stonith-watchdog-timeout (%s) too short "
"(must be >%ldms)", value, sbd_timeout);
crm_exit(CRM_EX_FATAL);
return false;
}
crm_info("Watchdog configured with stonith-watchdog-timeout %s and SBD timeout %ldms",
value, sbd_timeout);
}
return true;
}

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