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-rw-r--r--src/libshared/watchdog.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/src/libshared/watchdog.c b/src/libshared/watchdog.c
new file mode 100644
index 0000000000..4f3e0125f3
--- /dev/null
+++ b/src/libshared/watchdog.c
@@ -0,0 +1,164 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2012 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <linux/watchdog.h>
+
+#include "fd-util.h"
+#include "log.h"
+#include "time-util.h"
+#include "watchdog.h"
+
+static int watchdog_fd = -1;
+static usec_t watchdog_timeout = USEC_INFINITY;
+
+static int update_timeout(void) {
+ int r;
+
+ if (watchdog_fd < 0)
+ return 0;
+
+ if (watchdog_timeout == USEC_INFINITY)
+ return 0;
+ else if (watchdog_timeout == 0) {
+ int flags;
+
+ flags = WDIOS_DISABLECARD;
+ r = ioctl(watchdog_fd, WDIOC_SETOPTIONS, &flags);
+ if (r < 0)
+ return log_warning_errno(errno, "Failed to disable hardware watchdog: %m");
+ } else {
+ int sec, flags;
+ char buf[FORMAT_TIMESPAN_MAX];
+
+ sec = (int) ((watchdog_timeout + USEC_PER_SEC - 1) / USEC_PER_SEC);
+ r = ioctl(watchdog_fd, WDIOC_SETTIMEOUT, &sec);
+ if (r < 0)
+ return log_warning_errno(errno, "Failed to set timeout to %is: %m", sec);
+
+ watchdog_timeout = (usec_t) sec * USEC_PER_SEC;
+ log_info("Set hardware watchdog to %s.", format_timespan(buf, sizeof(buf), watchdog_timeout, 0));
+
+ flags = WDIOS_ENABLECARD;
+ r = ioctl(watchdog_fd, WDIOC_SETOPTIONS, &flags);
+ if (r < 0) {
+ /* ENOTTY means the watchdog is always enabled so we're fine */
+ log_full(errno == ENOTTY ? LOG_DEBUG : LOG_WARNING,
+ "Failed to enable hardware watchdog: %m");
+ if (errno != ENOTTY)
+ return -errno;
+ }
+
+ r = ioctl(watchdog_fd, WDIOC_KEEPALIVE, 0);
+ if (r < 0)
+ return log_warning_errno(errno, "Failed to ping hardware watchdog: %m");
+ }
+
+ return 0;
+}
+
+static int open_watchdog(void) {
+ struct watchdog_info ident;
+
+ if (watchdog_fd >= 0)
+ return 0;
+
+ watchdog_fd = open("/dev/watchdog", O_WRONLY|O_CLOEXEC);
+ if (watchdog_fd < 0)
+ return -errno;
+
+ if (ioctl(watchdog_fd, WDIOC_GETSUPPORT, &ident) >= 0)
+ log_info("Hardware watchdog '%s', version %x",
+ ident.identity,
+ ident.firmware_version);
+
+ return update_timeout();
+}
+
+int watchdog_set_timeout(usec_t *usec) {
+ int r;
+
+ watchdog_timeout = *usec;
+
+ /* If we didn't open the watchdog yet and didn't get any
+ * explicit timeout value set, don't do anything */
+ if (watchdog_fd < 0 && watchdog_timeout == USEC_INFINITY)
+ return 0;
+
+ if (watchdog_fd < 0)
+ r = open_watchdog();
+ else
+ r = update_timeout();
+
+ *usec = watchdog_timeout;
+
+ return r;
+}
+
+int watchdog_ping(void) {
+ int r;
+
+ if (watchdog_fd < 0) {
+ r = open_watchdog();
+ if (r < 0)
+ return r;
+ }
+
+ r = ioctl(watchdog_fd, WDIOC_KEEPALIVE, 0);
+ if (r < 0)
+ return log_warning_errno(errno, "Failed to ping hardware watchdog: %m");
+
+ return 0;
+}
+
+void watchdog_close(bool disarm) {
+ int r;
+
+ if (watchdog_fd < 0)
+ return;
+
+ if (disarm) {
+ int flags;
+
+ /* Explicitly disarm it */
+ flags = WDIOS_DISABLECARD;
+ r = ioctl(watchdog_fd, WDIOC_SETOPTIONS, &flags);
+ if (r < 0)
+ log_warning_errno(errno, "Failed to disable hardware watchdog: %m");
+
+ /* To be sure, use magic close logic, too */
+ for (;;) {
+ static const char v = 'V';
+
+ if (write(watchdog_fd, &v, 1) > 0)
+ break;
+
+ if (errno != EINTR) {
+ log_error_errno(errno, "Failed to disarm watchdog timer: %m");
+ break;
+ }
+ }
+ }
+
+ watchdog_fd = safe_close(watchdog_fd);
+}