1 /**
2 * collectd - src/collectd.c
3 * Copyright (C) 2005-2007 Florian octo Forster
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 * Florian octo Forster <octo at collectd.org>
25 * Alvaro Barcellos <alvaro.barcellos at gmail.com>
26 **/
28 #include "collectd.h"
29 #include "common.h"
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <netdb.h>
35 #include <pthread.h>
37 #include "plugin.h"
38 #include "configfile.h"
40 #if HAVE_STATGRAB_H
41 # include <statgrab.h>
42 #endif
44 /*
45 * Global variables
46 */
47 char hostname_g[DATA_MAX_NAME_LEN];
48 cdtime_t interval_g;
49 int pidfile_from_cli = 0;
50 int timeout_g;
51 #if HAVE_LIBKSTAT
52 kstat_ctl_t *kc;
53 #endif /* HAVE_LIBKSTAT */
55 static int loop = 0;
57 static void *do_flush (void __attribute__((unused)) *arg)
58 {
59 INFO ("Flushing all data.");
60 plugin_flush (/* plugin = */ NULL,
61 /* timeout = */ 0,
62 /* ident = */ NULL);
63 INFO ("Finished flushing all data.");
64 pthread_exit (NULL);
65 return NULL;
66 }
68 static void sig_int_handler (int __attribute__((unused)) signal)
69 {
70 loop++;
71 }
73 static void sig_term_handler (int __attribute__((unused)) signal)
74 {
75 loop++;
76 }
78 static void sig_usr1_handler (int __attribute__((unused)) signal)
79 {
80 pthread_t thread;
81 pthread_attr_t attr;
83 /* flushing the data might take a while,
84 * so it should be done asynchronously */
85 pthread_attr_init (&attr);
86 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
87 pthread_create (&thread, &attr, do_flush, NULL);
88 pthread_attr_destroy (&attr);
89 }
91 static int init_hostname (void)
92 {
93 const char *str;
95 struct addrinfo ai_hints;
96 struct addrinfo *ai_list;
97 struct addrinfo *ai_ptr;
98 int status;
100 str = global_option_get ("Hostname");
101 if (str != NULL)
102 {
103 sstrncpy (hostname_g, str, sizeof (hostname_g));
104 return (0);
105 }
107 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
108 {
109 fprintf (stderr, "`gethostname' failed and no "
110 "hostname was configured.\n");
111 return (-1);
112 }
114 str = global_option_get ("FQDNLookup");
115 if (IS_FALSE (str))
116 return (0);
118 memset (&ai_hints, '\0', sizeof (ai_hints));
119 ai_hints.ai_flags = AI_CANONNAME;
121 status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
122 if (status != 0)
123 {
124 ERROR ("Looking up \"%s\" failed. You have set the "
125 "\"FQDNLookup\" option, but I cannot resolve "
126 "my hostname to a fully qualified domain "
127 "name. Please fix the network "
128 "configuration.", hostname_g);
129 return (-1);
130 }
132 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
133 {
134 if (ai_ptr->ai_canonname == NULL)
135 continue;
137 sstrncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
138 break;
139 }
141 freeaddrinfo (ai_list);
142 return (0);
143 } /* int init_hostname */
145 static int init_global_variables (void)
146 {
147 char const *str;
149 interval_g = cf_get_default_interval ();
150 assert (interval_g > 0);
151 DEBUG ("interval_g = %.3f;", CDTIME_T_TO_DOUBLE (interval_g));
153 str = global_option_get ("Timeout");
154 if (str == NULL)
155 str = "2";
156 timeout_g = atoi (str);
157 if (timeout_g <= 1)
158 {
159 fprintf (stderr, "Cannot set the timeout to a correct value.\n"
160 "Please check your settings.\n");
161 return (-1);
162 }
163 DEBUG ("timeout_g = %i;", timeout_g);
165 if (init_hostname () != 0)
166 return (-1);
167 DEBUG ("hostname_g = %s;", hostname_g);
169 return (0);
170 } /* int init_global_variables */
172 static int change_basedir (const char *orig_dir)
173 {
174 char *dir;
175 size_t dirlen;
176 int status;
178 dir = strdup (orig_dir);
179 if (dir == NULL)
180 {
181 char errbuf[1024];
182 ERROR ("strdup failed: %s",
183 sstrerror (errno, errbuf, sizeof (errbuf)));
184 return (-1);
185 }
187 dirlen = strlen (dir);
188 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
189 dir[--dirlen] = '\0';
191 if (dirlen <= 0)
192 return (-1);
194 status = chdir (dir);
195 if (status == 0)
196 {
197 free (dir);
198 return (0);
199 }
200 else if (errno != ENOENT)
201 {
202 char errbuf[1024];
203 ERROR ("change_basedir: chdir (%s): %s", dir,
204 sstrerror (errno, errbuf, sizeof (errbuf)));
205 free (dir);
206 return (-1);
207 }
209 status = mkdir (dir, S_IRWXU | S_IRWXG | S_IRWXO);
210 if (status != 0)
211 {
212 char errbuf[1024];
213 ERROR ("change_basedir: mkdir (%s): %s", dir,
214 sstrerror (errno, errbuf, sizeof (errbuf)));
215 free (dir);
216 return (-1);
217 }
219 status = chdir (dir);
220 if (status != 0)
221 {
222 char errbuf[1024];
223 ERROR ("change_basedir: chdir (%s): %s", dir,
224 sstrerror (errno, errbuf, sizeof (errbuf)));
225 free (dir);
226 return (-1);
227 }
229 free (dir);
230 return (0);
231 } /* static int change_basedir (char *dir) */
233 #if HAVE_LIBKSTAT
234 static void update_kstat (void)
235 {
236 if (kc == NULL)
237 {
238 if ((kc = kstat_open ()) == NULL)
239 ERROR ("Unable to open kstat control structure");
240 }
241 else
242 {
243 kid_t kid;
244 kid = kstat_chain_update (kc);
245 if (kid > 0)
246 {
247 INFO ("kstat chain has been updated");
248 plugin_init_all ();
249 }
250 else if (kid < 0)
251 ERROR ("kstat chain update failed");
252 /* else: everything works as expected */
253 }
255 return;
256 } /* static void update_kstat (void) */
257 #endif /* HAVE_LIBKSTAT */
259 /* TODO
260 * Remove all settings but `-f' and `-C'
261 */
262 static void exit_usage (int status)
263 {
264 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
266 "Available options:\n"
267 " General:\n"
268 " -C <file> Configuration file.\n"
269 " Default: "CONFIGFILE"\n"
270 " -t Test config and exit.\n"
271 " -T Test plugin read and exit.\n"
272 " -P <file> PID-file.\n"
273 " Default: "PIDFILE"\n"
274 #if COLLECT_DAEMON
275 " -f Don't fork to the background.\n"
276 #endif
277 " -h Display help (this message)\n"
278 "\nBuiltin defaults:\n"
279 " Config file "CONFIGFILE"\n"
280 " PID file "PIDFILE"\n"
281 " Plugin directory "PLUGINDIR"\n"
282 " Data directory "PKGLOCALSTATEDIR"\n"
283 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
284 "by Florian octo Forster <octo@collectd.org>\n"
285 "for contributions see `AUTHORS'\n");
286 exit (status);
287 } /* static void exit_usage (int status) */
289 static int do_init (void)
290 {
291 #if HAVE_LIBKSTAT
292 kc = NULL;
293 update_kstat ();
294 #endif
296 #if HAVE_LIBSTATGRAB
297 if (sg_init ())
298 {
299 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
300 return (-1);
301 }
303 if (sg_drop_privileges ())
304 {
305 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
306 return (-1);
307 }
308 #endif
310 plugin_init_all ();
312 return (0);
313 } /* int do_init () */
316 static int do_loop (void)
317 {
318 cdtime_t interval = cf_get_default_interval ();
319 cdtime_t wait_until;
321 wait_until = cdtime () + interval;
323 while (loop == 0)
324 {
325 struct timespec ts_wait = { 0, 0 };
326 cdtime_t now;
328 #if HAVE_LIBKSTAT
329 update_kstat ();
330 #endif
332 /* Issue all plugins */
333 plugin_read_all ();
335 now = cdtime ();
336 if (now >= wait_until)
337 {
338 WARNING ("Not sleeping because the next interval is "
339 "%.3f seconds in the past!",
340 CDTIME_T_TO_DOUBLE (now - wait_until));
341 wait_until = now + interval;
342 continue;
343 }
345 CDTIME_T_TO_TIMESPEC (wait_until - now, &ts_wait);
346 wait_until = wait_until + interval;
348 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) != 0))
349 {
350 if (errno != EINTR)
351 {
352 char errbuf[1024];
353 ERROR ("nanosleep failed: %s",
354 sstrerror (errno, errbuf,
355 sizeof (errbuf)));
356 return (-1);
357 }
358 }
359 } /* while (loop == 0) */
361 return (0);
362 } /* int do_loop */
364 static int do_shutdown (void)
365 {
366 plugin_shutdown_all ();
367 return (0);
368 } /* int do_shutdown */
370 #if COLLECT_DAEMON
371 static int pidfile_create (void)
372 {
373 FILE *fh;
374 const char *file = global_option_get ("PIDFile");
376 if ((fh = fopen (file, "w")) == NULL)
377 {
378 char errbuf[1024];
379 ERROR ("fopen (%s): %s", file,
380 sstrerror (errno, errbuf, sizeof (errbuf)));
381 return (1);
382 }
384 fprintf (fh, "%i\n", (int) getpid ());
385 fclose(fh);
387 return (0);
388 } /* static int pidfile_create (const char *file) */
390 static int pidfile_remove (void)
391 {
392 const char *file = global_option_get ("PIDFile");
394 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
395 return (unlink (file));
396 } /* static int pidfile_remove (const char *file) */
397 #endif /* COLLECT_DAEMON */
399 int main (int argc, char **argv)
400 {
401 struct sigaction sig_int_action;
402 struct sigaction sig_term_action;
403 struct sigaction sig_usr1_action;
404 struct sigaction sig_pipe_action;
405 char *configfile = CONFIGFILE;
406 int test_config = 0;
407 int test_readall = 0;
408 const char *basedir;
409 #if COLLECT_DAEMON
410 struct sigaction sig_chld_action;
411 pid_t pid;
412 int daemonize = 1;
413 #endif
414 int exit_status = 0;
416 /* read options */
417 while (1)
418 {
419 int c;
421 c = getopt (argc, argv, "htTC:"
422 #if COLLECT_DAEMON
423 "fP:"
424 #endif
425 );
427 if (c == -1)
428 break;
430 switch (c)
431 {
432 case 'C':
433 configfile = optarg;
434 break;
435 case 't':
436 test_config = 1;
437 break;
438 case 'T':
439 test_readall = 1;
440 global_option_set ("ReadThreads", "-1");
441 #if COLLECT_DAEMON
442 daemonize = 0;
443 #endif /* COLLECT_DAEMON */
444 break;
445 #if COLLECT_DAEMON
446 case 'P':
447 global_option_set ("PIDFile", optarg);
448 pidfile_from_cli = 1;
449 break;
450 case 'f':
451 daemonize = 0;
452 break;
453 #endif /* COLLECT_DAEMON */
454 case 'h':
455 exit_usage (0);
456 break;
457 default:
458 exit_usage (1);
459 } /* switch (c) */
460 } /* while (1) */
462 if (optind < argc)
463 exit_usage (1);
465 plugin_init_ctx ();
467 /*
468 * Read options from the config file, the environment and the command
469 * line (in that order, with later options overwriting previous ones in
470 * general).
471 * Also, this will automatically load modules.
472 */
473 if (cf_read (configfile))
474 {
475 fprintf (stderr, "Error: Reading the config file failed!\n"
476 "Read the syslog for details.\n");
477 return (1);
478 }
480 /*
481 * Change directory. We do this _after_ reading the config and loading
482 * modules to relative paths work as expected.
483 */
484 if ((basedir = global_option_get ("BaseDir")) == NULL)
485 {
486 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
487 return (1);
488 }
489 else if (change_basedir (basedir))
490 {
491 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
492 return (1);
493 }
495 /*
496 * Set global variables or, if that failes, exit. We cannot run with
497 * them being uninitialized. If nothing is configured, then defaults
498 * are being used. So this means that the user has actually done
499 * something wrong.
500 */
501 if (init_global_variables () != 0)
502 return (1);
504 if (test_config)
505 return (0);
507 #if COLLECT_DAEMON
508 /*
509 * fork off child
510 */
511 memset (&sig_chld_action, '\0', sizeof (sig_chld_action));
512 sig_chld_action.sa_handler = SIG_IGN;
513 sigaction (SIGCHLD, &sig_chld_action, NULL);
515 if (daemonize)
516 {
517 if ((pid = fork ()) == -1)
518 {
519 /* error */
520 char errbuf[1024];
521 fprintf (stderr, "fork: %s",
522 sstrerror (errno, errbuf,
523 sizeof (errbuf)));
524 return (1);
525 }
526 else if (pid != 0)
527 {
528 /* parent */
529 /* printf ("Running (PID %i)\n", pid); */
530 return (0);
531 }
533 /* Detach from session */
534 setsid ();
536 /* Write pidfile */
537 if (pidfile_create ())
538 exit (2);
540 /* close standard descriptors */
541 close (2);
542 close (1);
543 close (0);
545 if (open ("/dev/null", O_RDWR) != 0)
546 {
547 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
548 return (1);
549 }
550 if (dup (0) != 1)
551 {
552 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
553 return (1);
554 }
555 if (dup (0) != 2)
556 {
557 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
558 return (1);
559 }
560 } /* if (daemonize) */
561 #endif /* COLLECT_DAEMON */
563 memset (&sig_pipe_action, '\0', sizeof (sig_pipe_action));
564 sig_pipe_action.sa_handler = SIG_IGN;
565 sigaction (SIGPIPE, &sig_pipe_action, NULL);
567 /*
568 * install signal handlers
569 */
570 memset (&sig_int_action, '\0', sizeof (sig_int_action));
571 sig_int_action.sa_handler = sig_int_handler;
572 if (0 != sigaction (SIGINT, &sig_int_action, NULL)) {
573 char errbuf[1024];
574 ERROR ("Error: Failed to install a signal handler for signal INT: %s",
575 sstrerror (errno, errbuf, sizeof (errbuf)));
576 return (1);
577 }
579 memset (&sig_term_action, '\0', sizeof (sig_term_action));
580 sig_term_action.sa_handler = sig_term_handler;
581 if (0 != sigaction (SIGTERM, &sig_term_action, NULL)) {
582 char errbuf[1024];
583 ERROR ("Error: Failed to install a signal handler for signal TERM: %s",
584 sstrerror (errno, errbuf, sizeof (errbuf)));
585 return (1);
586 }
588 memset (&sig_usr1_action, '\0', sizeof (sig_usr1_action));
589 sig_usr1_action.sa_handler = sig_usr1_handler;
590 if (0 != sigaction (SIGUSR1, &sig_usr1_action, NULL)) {
591 char errbuf[1024];
592 ERROR ("Error: Failed to install a signal handler for signal USR1: %s",
593 sstrerror (errno, errbuf, sizeof (errbuf)));
594 return (1);
595 }
597 /*
598 * run the actual loops
599 */
600 do_init ();
602 if (test_readall)
603 {
604 if (plugin_read_all_once () != 0)
605 exit_status = 1;
606 }
607 else
608 {
609 INFO ("Initialization complete, entering read-loop.");
610 do_loop ();
611 }
613 /* close syslog */
614 INFO ("Exiting normally.");
616 do_shutdown ();
618 #if COLLECT_DAEMON
619 if (daemonize)
620 pidfile_remove ();
621 #endif /* COLLECT_DAEMON */
623 return (exit_status);
624 } /* int main */