mirror of
https://github.com/troglobit/finit.git
synced 2026-10-02 05:52:48 +07:00
Joachim Nilsson
b674aad802
This patch adds a simple but effective watchdog daemon with support for
handover to an external daemon, should one register using the API.
Disabled by default, enable by:
configure --enable-watchdog
The watchdog forks to the background, opening /dev/watchdog setting a
three second timeout, and kicking every second. At shutdown/reboot the
daemon will receive SIGPWR from Finit to exit and cause a WDT reboot.
Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
136 lines
2.8 KiB
C
136 lines
2.8 KiB
C
/* Built-in watchdog daemon
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*
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* Copyright (c) 2016 Joachim Nilsson <troglobit@gmail.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <paths.h>
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#include <sys/un.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <linux/watchdog.h>
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#include "finit.h"
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#include "helpers.h"
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#include "watchdog.h"
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int running = 1;
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int handover = 0;
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static int notify(void)
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{
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int sd, result = 255;
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ssize_t len;
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struct sockaddr_un sun = {
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.sun_family = AF_UNIX,
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.sun_path = INIT_SOCKET,
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};
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struct init_request rq;
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sd = socket(AF_UNIX, SOCK_STREAM, 0);
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if (-1 == sd)
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return -1;
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if (connect(sd, (struct sockaddr*)&sun, sizeof(sun)) == -1)
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goto exit;
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rq.cmd = INIT_CMD_WDOG_HELLO;
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rq.magic = INIT_MAGIC;
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rq.runlevel = getpid();
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len = sizeof(rq);
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if (write(sd, &rq, len) != len)
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goto exit;
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if (read(sd, &rq, len) != len)
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goto exit;
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result = 0;
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exit:
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close(sd);
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return result;
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}
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static void sighandler(int signo)
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{
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if (signo == SIGTERM)
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handover = 1;
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running = 0;
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}
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static int init(char *progname, char *devnode, int timeout)
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{
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int fd;
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sprintf(progname, "@finit-watchdog");
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signal(SIGTERM, sighandler);
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signal(SIGPWR, sighandler);
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fd = open(devnode, O_WRONLY);
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if (fd == -1)
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return -1;
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ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
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return fd;
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}
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static int loop(int fd)
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{
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int done = 0;
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while (running) {
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do_sleep(1);
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ioctl(fd, WDIOC_KEEPALIVE, &done);
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if (!done && !notify())
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done = 1;
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}
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if (handover)
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return !write(fd, "V", 1);
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return 0;
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}
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void watchdog(char *progname)
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{
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if (fork() == 0) {
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int fd, ret;
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fd = init(progname, WDT_DEVNODE, WDT_TIMEOUT);
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if (fd == -1) {
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_pe("Failed connecting to watchdog %s", WDT_DEVNODE);
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_exit(1);
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}
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ret = loop(fd);
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close(fd);
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_exit(ret);
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}
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}
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/**
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* Local Variables:
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* indent-tabs-mode: t
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* c-file-style: "linux"
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* End:
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*/
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