1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <errno.h>
18#include <fcntl.h>
19#include <linux/watchdog.h>
20#include <stdlib.h>
21#include <string.h>
22#include <unistd.h>
23
24#include <android-base/logging.h>
25
26#include "log.h"
27
28#ifdef _INIT_INIT_H
29#error "Do not include init.h in files used by ueventd or watchdogd; it will expose init's globals"
30#endif
31
32#define DEV_NAME "/dev/watchdog"
33
34namespace android {
35namespace init {
36
37int watchdogd_main(int argc, char **argv) {
38    InitKernelLogging(argv);
39
40    int interval = 10;
41    if (argc >= 2) interval = atoi(argv[1]);
42
43    int margin = 10;
44    if (argc >= 3) margin = atoi(argv[2]);
45
46    LOG(INFO) << "watchdogd started (interval " << interval << ", margin " << margin << ")!";
47
48    int fd = open(DEV_NAME, O_RDWR|O_CLOEXEC);
49    if (fd == -1) {
50        PLOG(ERROR) << "Failed to open " << DEV_NAME;
51        return 1;
52    }
53
54    int timeout = interval + margin;
55    int ret = ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
56    if (ret) {
57        PLOG(ERROR) << "Failed to set timeout to " << timeout;
58        ret = ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
59        if (ret) {
60            PLOG(ERROR) << "Failed to get timeout";
61        } else {
62            if (timeout > margin) {
63                interval = timeout - margin;
64            } else {
65                interval = 1;
66            }
67            LOG(WARNING) << "Adjusted interval to timeout returned by driver: "
68                         << "timeout " << timeout
69                         << ", interval " << interval
70                         << ", margin " << margin;
71        }
72    }
73
74    while (true) {
75        write(fd, "", 1);
76        sleep(interval);
77    }
78}
79
80}  // namespace init
81}  // namespace android
82