X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fwatchdog.c;fp=src%2Fwatchdog.c;h=9625e151af1ee5190a3ba422379697c8b3d8613d;hb=e96d6be763014be75d480fde503d0b77f41194a0;hp=0000000000000000000000000000000000000000;hpb=348e27fedfd4cdd2238ff31a46785a70b9dc6fc0;p=elogind.git

diff --git a/src/watchdog.c b/src/watchdog.c
new file mode 100644
index 000000000..9625e151a
--- /dev/null
+++ b/src/watchdog.c
@@ -0,0 +1,166 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <linux/watchdog.h>
+
+#include "watchdog.h"
+#include "log.h"
+
+static int watchdog_fd = -1;
+static usec_t watchdog_timeout = (usec_t) -1;
+
+static int update_timeout(void) {
+        int r;
+
+        if (watchdog_fd < 0)
+                return 0;
+
+        if (watchdog_timeout == (usec_t) -1)
+                return 0;
+        else if (watchdog_timeout == 0) {
+                int flags;
+
+                flags = WDIOS_DISABLECARD;
+                r = ioctl(watchdog_fd, WDIOC_SETOPTIONS, &flags);
+                if (r < 0) {
+                        log_warning("Failed to disable hardware watchdog: %m");
+                        return -errno;
+                }
+        } 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) {
+                        log_warning("Failed to set timeout to %is: %m", sec);
+                        return -errno;
+                }
+
+                watchdog_timeout = (usec_t) sec * USEC_PER_SEC;
+                log_info("Set hardware watchdog to %s.", format_timespan(buf, sizeof(buf), watchdog_timeout));
+
+                flags = WDIOS_ENABLECARD;
+                r = ioctl(watchdog_fd, WDIOC_SETOPTIONS, &flags);
+                if (r < 0) {
+                        log_warning("Failed to enable hardware watchdog: %m");
+                        return -errno;
+                }
+
+                r = ioctl(watchdog_fd, WDIOC_KEEPALIVE, 0);
+                if (r < 0) {
+                        log_warning("Failed to ping hardware watchdog: %m");
+                        return -errno;
+                }
+        }
+
+        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) {
+
+        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_t) -1)
+                return 0;
+
+        if (watchdog_fd < 0)
+                return open_watchdog();
+        else
+                return update_timeout();
+
+        *usec = watchdog_timeout;
+}
+
+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) {
+                log_warning("Failed to ping hardware watchdog: %m");
+                return -errno;
+        }
+
+        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("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("Failed to disarm watchdog timer: %m");
+                                break;
+                        }
+                }
+        }
+
+        close_nointr_nofail(watchdog_fd);
+        watchdog_fd = -1;
+}