1 /**
2 * collectd - src/collectdmon.c
3 * Copyright (C) 2007 Sebastian Harl
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Sebastian Harl <sh at tokkee.org>
25 **/
27 #if !defined(__GNUC__) || !__GNUC__
28 # define __attribute__(x) /**/
29 #endif
31 #include "config.h"
33 #include <assert.h>
35 #include <errno.h>
37 #include <fcntl.h>
39 #include <signal.h>
41 #include <stdio.h>
42 #include <stdlib.h>
44 #include <string.h>
46 #include <syslog.h>
48 #include <sys/resource.h>
49 #include <sys/time.h>
50 #include <sys/types.h>
51 #include <sys/stat.h>
52 #include <sys/wait.h>
54 #include <time.h>
56 #include <unistd.h>
58 #ifndef COLLECTDMON_PIDFILE
59 # define COLLECTDMON_PIDFILE LOCALSTATEDIR"/run/collectdmon.pid"
60 #endif /* ! COLLECTDMON_PIDFILE */
62 #ifndef WCOREDUMP
63 # define WCOREDUMP(s) 0
64 #endif /* ! WCOREDUMP */
66 static int loop = 0;
67 static int restart = 0;
69 static char *pidfile = NULL;
70 static pid_t collectd_pid = 0;
72 static void exit_usage (char *name)
73 {
74 printf ("Usage: %s <options> [-- <collectd options>]\n"
76 "\nAvailable options:\n"
77 " -h Display this help and exit.\n"
78 " -c <path> Path to the collectd binary.\n"
79 " -P <file> PID-file.\n"
81 "\nFor <collectd options> see collectd.conf(5).\n"
83 "\n"PACKAGE_NAME" "PACKAGE_VERSION", http://collectd.org/\n"
84 "by Florian octo Forster <octo@collectd.org>\n"
85 "for contributions see `AUTHORS'\n", name);
86 exit (0);
87 } /* exit_usage */
89 static int pidfile_create (void)
90 {
91 FILE *file = NULL;
93 if (NULL == pidfile)
94 pidfile = COLLECTDMON_PIDFILE;
96 if (NULL == (file = fopen (pidfile, "w"))) {
97 syslog (LOG_ERR, "Error: couldn't open PID-file (%s) for writing: %s",
98 pidfile, strerror (errno));
99 return -1;
100 }
102 fprintf (file, "%i\n", (int)getpid ());
103 fclose (file);
104 return 0;
105 } /* pidfile_create */
107 static int pidfile_delete (void)
108 {
109 assert (NULL != pidfile);
111 if (0 != unlink (pidfile)) {
112 syslog (LOG_ERR, "Error: couldn't delete PID-file (%s): %s",
113 pidfile, strerror (errno));
114 return -1;
115 }
116 return 0;
117 } /* pidfile_remove */
119 static int daemonize (void)
120 {
121 struct rlimit rl;
122 int dev_null;
124 pid_t pid = 0;
125 int i = 0;
127 if (0 != chdir ("/")) {
128 fprintf (stderr, "Error: chdir() failed: %s\n", strerror (errno));
129 return -1;
130 }
132 if (0 != getrlimit (RLIMIT_NOFILE, &rl)) {
133 fprintf (stderr, "Error: getrlimit() failed: %s\n", strerror (errno));
134 return -1;
135 }
137 if (0 > (pid = fork ())) {
138 fprintf (stderr, "Error: fork() failed: %s\n", strerror (errno));
139 return -1;
140 }
141 else if (pid != 0) {
142 exit (0);
143 }
145 if (0 != pidfile_create ())
146 return -1;
148 setsid ();
150 if (RLIM_INFINITY == rl.rlim_max)
151 rl.rlim_max = 1024;
153 for (i = 0; i < (int)rl.rlim_max; ++i)
154 close (i);
156 dev_null = open ("/dev/null", O_RDWR);
157 if (dev_null == -1) {
158 syslog (LOG_ERR, "Error: couldn't failed to open /dev/null: %s", strerror (errno));
159 return -1;
160 }
162 if (dup2 (dev_null, STDIN_FILENO) == -1) {
163 syslog (LOG_ERR, "Error: couldn't connect STDIN to /dev/null: %s", strerror (errno));
164 return -1;
165 }
167 if (dup2 (dev_null, STDOUT_FILENO) == -1) {
168 syslog (LOG_ERR, "Error: couldn't connect STDOUT to /dev/null: %s", strerror (errno));
169 return -1;
170 }
172 if (dup2 (dev_null, STDERR_FILENO) == -1) {
173 syslog (LOG_ERR, "Error: couldn't connect STDERR to /dev/null: %s", strerror (errno));
174 return -1;
175 }
177 if ((dev_null != STDIN_FILENO) && (dev_null != STDOUT_FILENO) && (dev_null != STDERR_FILENO))
178 close (dev_null);
180 return 0;
181 } /* daemonize */
183 static int collectd_start (char **argv)
184 {
185 pid_t pid = 0;
187 if (0 > (pid = fork ())) {
188 syslog (LOG_ERR, "Error: fork() failed: %s", strerror (errno));
189 return -1;
190 }
191 else if (pid != 0) {
192 collectd_pid = pid;
193 return 0;
194 }
196 execvp (argv[0], argv);
197 syslog (LOG_ERR, "Error: execvp(%s) failed: %s",
198 argv[0], strerror (errno));
199 exit (-1);
200 } /* collectd_start */
202 static int collectd_stop (void)
203 {
204 if (0 == collectd_pid)
205 return 0;
207 if (0 != kill (collectd_pid, SIGTERM)) {
208 syslog (LOG_ERR, "Error: kill() failed: %s", strerror (errno));
209 return -1;
210 }
211 return 0;
212 } /* collectd_stop */
214 static void sig_int_term_handler (int __attribute__((unused)) signo)
215 {
216 ++loop;
217 return;
218 } /* sig_int_term_handler */
220 static void sig_hup_handler (int __attribute__((unused)) signo)
221 {
222 ++restart;
223 return;
224 } /* sig_hup_handler */
226 static void log_status (int status)
227 {
228 if (WIFEXITED (status)) {
229 if (0 == WEXITSTATUS (status))
230 syslog (LOG_INFO, "Info: collectd terminated with exit status %i",
231 WEXITSTATUS (status));
232 else
233 syslog (LOG_WARNING,
234 "Warning: collectd terminated with exit status %i",
235 WEXITSTATUS (status));
236 }
237 else if (WIFSIGNALED (status)) {
238 syslog (LOG_WARNING, "Warning: collectd was terminated by signal %i%s",
239 WTERMSIG (status), WCOREDUMP (status) ? " (core dumped)" : "");
240 }
241 return;
242 } /* log_status */
244 static void check_respawn (void)
245 {
246 time_t t = time (NULL);
248 static time_t timestamp = 0;
249 static int counter = 0;
251 if ((t - 120) < timestamp)
252 ++counter;
253 else {
254 timestamp = t;
255 counter = 0;
256 }
258 if (10 < counter) {
259 unsigned int time_left = 300;
261 syslog (LOG_ERR, "Error: collectd is respawning too fast - "
262 "disabled for %i seconds", time_left);
264 while ((0 < (time_left = sleep (time_left))) && (0 == loop));
265 }
266 return;
267 } /* check_respawn */
269 int main (int argc, char **argv)
270 {
271 int collectd_argc = 0;
272 char *collectd = NULL;
273 char **collectd_argv = NULL;
275 struct sigaction sa;
277 int i = 0;
279 /* parse command line options */
280 while (42) {
281 int c = getopt (argc, argv, "hc:P:");
283 if (-1 == c)
284 break;
286 switch (c) {
287 case 'c':
288 collectd = optarg;
289 break;
290 case 'P':
291 pidfile = optarg;
292 break;
293 case 'h':
294 default:
295 exit_usage (argv[0]);
296 }
297 }
299 for (i = optind; i < argc; ++i)
300 if (0 == strcmp (argv[i], "-f"))
301 break;
303 /* i < argc => -f already present */
304 collectd_argc = 1 + argc - optind + ((i < argc) ? 0 : 1);
305 collectd_argv = (char **)calloc (collectd_argc + 1, sizeof (char *));
307 if (NULL == collectd_argv) {
308 fprintf (stderr, "Out of memory.");
309 return 3;
310 }
312 collectd_argv[0] = (NULL == collectd) ? "collectd" : collectd;
314 if (i == argc)
315 collectd_argv[collectd_argc - 1] = "-f";
317 for (i = optind; i < argc; ++i)
318 collectd_argv[i - optind + 1] = argv[i];
320 collectd_argv[collectd_argc] = NULL;
322 openlog ("collectdmon", LOG_CONS | LOG_PID, LOG_DAEMON);
324 if (-1 == daemonize ())
325 {
326 free (collectd_argv);
327 return 1;
328 }
330 sa.sa_handler = sig_int_term_handler;
331 sa.sa_flags = 0;
332 sigemptyset (&sa.sa_mask);
334 if (0 != sigaction (SIGINT, &sa, NULL)) {
335 syslog (LOG_ERR, "Error: sigaction() failed: %s", strerror (errno));
336 free (collectd_argv);
337 return 1;
338 }
340 if (0 != sigaction (SIGTERM, &sa, NULL)) {
341 syslog (LOG_ERR, "Error: sigaction() failed: %s", strerror (errno));
342 free (collectd_argv);
343 return 1;
344 }
346 sa.sa_handler = sig_hup_handler;
348 if (0 != sigaction (SIGHUP, &sa, NULL)) {
349 syslog (LOG_ERR, "Error: sigaction() failed: %s", strerror (errno));
350 free (collectd_argv);
351 return 1;
352 }
354 while (0 == loop) {
355 int status = 0;
357 if (0 != collectd_start (collectd_argv)) {
358 syslog (LOG_ERR, "Error: failed to start collectd.");
359 break;
360 }
362 assert (0 < collectd_pid);
363 while ((collectd_pid != waitpid (collectd_pid, &status, 0))
364 && (EINTR == errno))
365 if ((0 != loop) || (0 != restart))
366 collectd_stop ();
368 collectd_pid = 0;
370 log_status (status);
371 check_respawn ();
373 if (0 != restart) {
374 syslog (LOG_INFO, "Info: restarting collectd");
375 restart = 0;
376 }
377 else if (0 == loop)
378 syslog (LOG_WARNING, "Warning: restarting collectd");
379 }
381 syslog (LOG_INFO, "Info: shutting down collectdmon");
383 pidfile_delete ();
384 closelog ();
386 free (collectd_argv);
387 return 0;
388 } /* main */
390 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */