| /*-*- 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 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 <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, 0)); |
| |
| 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) { |
| 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_t) -1) |
| 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) { |
| 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; |
| } |
| } |
| } |
| |
| watchdog_fd = safe_close(watchdog_fd); |
| } |