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064af421 BP |
1 | /* Copyright (c) 2008, 2009 Nicira Networks, Inc. |
2 | * | |
a14bc59f BP |
3 | * Licensed under the Apache License, Version 2.0 (the "License"); |
4 | * you may not use this file except in compliance with the License. | |
5 | * You may obtain a copy of the License at: | |
064af421 | 6 | * |
a14bc59f | 7 | * http://www.apache.org/licenses/LICENSE-2.0 |
064af421 | 8 | * |
a14bc59f BP |
9 | * Unless required by applicable law or agreed to in writing, software |
10 | * distributed under the License is distributed on an "AS IS" BASIS, | |
11 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
12 | * See the License for the specific language governing permissions and | |
13 | * limitations under the License. | |
064af421 BP |
14 | */ |
15 | ||
16 | #include <stdio.h> | |
17 | #include <stdlib.h> | |
18 | #include <string.h> | |
19 | #include <unistd.h> | |
20 | #include <fcntl.h> | |
21 | #include <errno.h> | |
22 | #include <getopt.h> | |
23 | #include <signal.h> | |
24 | #include <sys/ioctl.h> | |
25 | #include <linux/types.h> | |
26 | #include <linux/watchdog.h> | |
27 | ||
28 | ||
29 | /* Default values for the interval and timer. In seconds. */ | |
30 | #define DEFAULT_INTERVAL 1 | |
31 | #define DEFAULT_TIMEOUT 30 | |
32 | ||
33 | int fd = -1; | |
34 | ||
35 | /* The WDT is automatically enabled when /dev/watchdog is opened. If we | |
36 | * do not send the magic value to the device first before exiting, the | |
37 | * system will reboot. This function allows the program to exit without | |
38 | * causing a reboot. | |
39 | */ | |
40 | static void | |
41 | cleanup(void) | |
42 | { | |
43 | if (fd == -1) { | |
44 | return; | |
45 | } | |
46 | ||
47 | /* Writing the magic value "V" to the device is an indication that | |
48 | * the device is about to be closed. This causes the watchdog to be | |
49 | * disabled after the call to close. | |
50 | */ | |
51 | if (write(fd, "V", 1) != 1) { | |
52 | fprintf(stderr, "Couldn't write magic val: %d\n", errno); | |
53 | return; | |
54 | } | |
55 | close(fd); | |
56 | fd = -1; | |
57 | } | |
58 | ||
59 | ||
60 | /* If we receive a SIGINT, cleanup first, which will disable the | |
61 | * watchdog timer. | |
62 | */ | |
63 | static void | |
64 | sighandler(int signum) | |
65 | { | |
66 | cleanup(); | |
67 | signal(signum, SIG_DFL); | |
68 | raise(signum); | |
69 | } | |
70 | ||
71 | static void | |
72 | setup_signal(void) | |
73 | { | |
74 | struct sigaction action; | |
75 | ||
76 | action.sa_handler = sighandler; | |
77 | sigemptyset(&action.sa_mask); | |
78 | action.sa_flags = 0; | |
79 | ||
80 | if (sigaction(SIGINT, &action, NULL) != 0) { | |
81 | fprintf(stderr, "Problem setting up SIGINT handler...\n"); | |
82 | } | |
83 | if (sigaction(SIGTERM, &action, NULL) != 0) { | |
84 | fprintf(stderr, "Problem setting up SIGTERM handler...\n"); | |
85 | } | |
86 | } | |
87 | ||
88 | ||
89 | /* Print information on the WDT hardware */ | |
90 | static void | |
91 | print_wdt_info(void) | |
92 | { | |
93 | struct watchdog_info ident; | |
94 | ||
95 | if (ioctl(fd, WDIOC_GETSUPPORT, &ident) == -1) { | |
96 | fprintf(stderr, "Couldn't get version: %d\n", errno); | |
97 | cleanup(); | |
98 | exit(-1); | |
99 | } | |
100 | printf("identity: %s, ver: %d, opt: %#x\n", ident.identity, | |
101 | ident.firmware_version, ident.options); | |
102 | } | |
103 | ||
104 | ||
105 | static void | |
106 | print_help(char *progname) | |
107 | { | |
108 | printf("%s: Watchdog timer utility\n", progname); | |
109 | printf("usage: %s [OPTIONS]\n\n", progname); | |
110 | printf("Options:\n"); | |
111 | printf(" -t, --timeout=SECS expiration time of WDT (default: %d)\n", | |
112 | DEFAULT_TIMEOUT); | |
113 | printf(" -i, --interval=SECS interval to send keep-alives (default: %d)\n", | |
114 | DEFAULT_INTERVAL); | |
115 | printf(" -d, --disable disable the WDT and exit\n"); | |
116 | printf(" -h, --help display this help message\n"); | |
117 | printf(" -v, --verbose enable verbose printing\n"); | |
118 | printf(" -V, --version display version information of WDT and exit\n"); | |
119 | } | |
120 | ||
121 | ||
122 | int main(int argc, char *argv[]) | |
123 | { | |
124 | int arg; | |
125 | int optc; | |
126 | int verbose = 0; | |
127 | int interval = DEFAULT_INTERVAL; | |
128 | int timeout = DEFAULT_TIMEOUT; | |
129 | static struct option const longopts[] = | |
130 | { | |
131 | {"timeout", required_argument, NULL, 't'}, | |
132 | {"interval", required_argument, NULL, 'i'}, | |
133 | {"disable", no_argument, NULL, 'd'}, | |
134 | {"help", no_argument, NULL, 'h'}, | |
135 | {"verbose", no_argument, NULL, 'v'}, | |
136 | {"version", no_argument, NULL, 'V'}, | |
137 | {0, 0, 0, 0} | |
138 | }; | |
139 | ||
140 | setup_signal(); | |
141 | ||
142 | fd = open("/dev/watchdog", O_RDWR); | |
143 | if (fd == -1) { | |
144 | fprintf(stderr, "Couldn't open watchdog device: %s\n", strerror(errno)); | |
145 | exit(-1); | |
146 | } | |
147 | ||
148 | while ((optc = getopt_long(argc, argv, "t:i:dh?vV", longopts, NULL)) != -1) { | |
149 | switch (optc) { | |
150 | case 't': | |
151 | timeout = strtol(optarg, NULL, 10); | |
152 | if (!timeout) { | |
153 | fprintf(stderr, "Invalid timeout: %s\n", optarg); | |
154 | goto error; | |
155 | } | |
156 | break; | |
157 | ||
158 | case 'i': | |
159 | interval = strtol(optarg, NULL, 10); | |
160 | if (!interval) { | |
161 | fprintf(stderr, "Invalid interval: %s\n", optarg); | |
162 | goto error; | |
163 | } | |
164 | break; | |
165 | ||
166 | case 'd': | |
167 | arg = WDIOS_DISABLECARD; | |
168 | if (ioctl(fd, WDIOC_SETOPTIONS, &arg) == -1) { | |
169 | fprintf(stderr, "Couldn't disable: %d\n", errno); | |
170 | goto error; | |
171 | } | |
172 | cleanup(); | |
173 | exit(0); | |
174 | break; | |
175 | ||
176 | case 'h': | |
177 | print_help(argv[0]); | |
178 | cleanup(); | |
179 | exit(0); | |
180 | break; | |
181 | ||
182 | case 'v': | |
183 | verbose = 1; | |
184 | break; | |
185 | ||
186 | case 'V': | |
187 | print_wdt_info(); | |
188 | cleanup(); | |
189 | exit(0); | |
190 | break; | |
191 | ||
192 | default: | |
193 | print_help(argv[0]); | |
194 | goto error; | |
195 | break; | |
196 | } | |
197 | } | |
198 | ||
199 | argc -= optind; | |
200 | argv += optind; | |
201 | ||
202 | /* Sanity-check the arguments */ | |
203 | if (argc != 0) { | |
204 | fprintf(stderr, "Illegal argument: %s\n", argv[0]); | |
205 | goto error; | |
206 | } | |
207 | ||
208 | if (verbose) { | |
209 | print_wdt_info(); | |
210 | printf("timeout: %d, interval: %d\n", timeout, interval); | |
211 | } | |
212 | ||
213 | /* Prevent the interval being greater than the timeout, since it | |
214 | * will always cause a reboot. | |
215 | */ | |
216 | if (interval > timeout) { | |
217 | fprintf(stderr, "Interval greater than timeout: %d > %d\n", | |
218 | interval, timeout); | |
219 | goto error; | |
220 | } | |
221 | ||
222 | /* Always set the timeout */ | |
223 | if (ioctl(fd, WDIOC_SETTIMEOUT, &timeout) == -1) { | |
224 | fprintf(stderr, "Couldn't set timeout: %d\n", errno); | |
225 | goto error; | |
226 | } | |
227 | ||
228 | /* Loop and send a keep-alive every "interval" seconds */ | |
229 | while (1) { | |
230 | if (verbose) { | |
231 | if (ioctl(fd, WDIOC_GETTIMELEFT, &arg) == -1) { | |
232 | fprintf(stderr, "Couldn't get time left: %d\n", errno); | |
233 | goto error; | |
234 | } | |
235 | printf("Sending keep alive, time remaining: %d\n", arg); | |
236 | } | |
237 | ||
238 | /* Send a keep-alive. The argument is ignored */ | |
239 | if (ioctl(fd, WDIOC_KEEPALIVE, &arg) == -1) { | |
240 | fprintf(stderr, "Couldn't keepalive: %d\n", errno); | |
241 | goto error; | |
242 | } | |
243 | ||
244 | sleep(interval); | |
245 | } | |
246 | ||
247 | /* Never directly reached... */ | |
248 | error: | |
249 | cleanup(); | |
250 | exit(-1); | |
251 | } |