1 /**
2 * collectd - src/collectd.c
3 * Copyright (C) 2005-2007 Florian octo Forster
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Florian octo Forster <octo at verplant.org>
20 * Alvaro Barcellos <alvaro.barcellos at gmail.com>
21 **/
23 #include "collectd.h"
24 #include "common.h"
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <netdb.h>
30 #include <pthread.h>
32 #include "plugin.h"
33 #include "configfile.h"
35 /*
36 * Global variables
37 */
38 char hostname_g[DATA_MAX_NAME_LEN];
39 int interval_g;
40 #if HAVE_LIBKSTAT
41 kstat_ctl_t *kc;
42 #endif /* HAVE_LIBKSTAT */
44 static int loop = 0;
46 static void *do_flush (void *arg)
47 {
48 INFO ("Flushing all data.");
49 plugin_flush_all (-1);
50 INFO ("Finished flushing all data.");
51 pthread_exit (NULL);
52 return NULL;
53 }
55 static void sig_int_handler (int signal)
56 {
57 loop++;
58 }
60 static void sig_term_handler (int signal)
61 {
62 loop++;
63 }
65 static void sig_usr1_handler (int signal)
66 {
67 pthread_t thread;
68 pthread_attr_t attr;
70 /* flushing the data might take a while,
71 * so it should be done asynchronously */
72 pthread_attr_init (&attr);
73 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
74 pthread_create (&thread, &attr, do_flush, NULL);
75 }
77 static int init_hostname (void)
78 {
79 const char *str;
81 struct addrinfo ai_hints;
82 struct addrinfo *ai_list;
83 struct addrinfo *ai_ptr;
84 int status;
86 str = global_option_get ("Hostname");
87 if (str != NULL)
88 {
89 strncpy (hostname_g, str, sizeof (hostname_g));
90 hostname_g[sizeof (hostname_g) - 1] = '\0';
91 return (0);
92 }
94 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
95 {
96 fprintf (stderr, "`gethostname' failed and no "
97 "hostname was configured.\n");
98 return (-1);
99 }
101 str = global_option_get ("FQDNLookup");
102 if ((strcasecmp ("false", str) == 0)
103 || (strcasecmp ("no", str) == 0)
104 || (strcasecmp ("off", str) == 0))
105 return (0);
107 memset (&ai_hints, '\0', sizeof (ai_hints));
108 ai_hints.ai_flags = AI_CANONNAME;
110 status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
111 if (status != 0)
112 {
113 ERROR ("Looking up \"%s\" failed. You have set the "
114 "\"FQDNLookup\" option, but I cannot resolve "
115 "my hostname to a fully qualified domain "
116 "name. Please fix you network "
117 "configuration.", hostname_g);
118 return (-1);
119 }
121 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
122 {
123 if (ai_ptr->ai_canonname == NULL)
124 continue;
126 strncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
127 hostname_g[sizeof (hostname_g) - 1] = '\0';
128 break;
129 }
131 freeaddrinfo (ai_list);
132 return (0);
133 } /* int init_hostname */
135 static int init_global_variables (void)
136 {
137 const char *str;
139 str = global_option_get ("Interval");
140 if (str == NULL)
141 str = "10";
142 interval_g = atoi (str);
143 if (interval_g <= 0)
144 {
145 fprintf (stderr, "Cannot set the interval to a correct value.\n"
146 "Please check your settings.\n");
147 return (-1);
148 }
149 DEBUG ("interval_g = %i;", interval_g);
151 if (init_hostname () != 0)
152 return (-1);
153 DEBUG ("hostname_g = %s;", hostname_g);
155 return (0);
156 } /* int init_global_variables */
158 static int change_basedir (const char *orig_dir)
159 {
160 char *dir = strdup (orig_dir);
161 int dirlen;
162 int status;
164 if (dir == NULL)
165 {
166 char errbuf[1024];
167 ERROR ("strdup failed: %s",
168 sstrerror (errno, errbuf, sizeof (errbuf)));
169 return (-1);
170 }
172 dirlen = strlen (dir);
173 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
174 dir[--dirlen] = '\0';
176 if (dirlen <= 0)
177 return (-1);
179 status = chdir (dir);
180 free (dir);
182 if (status != 0)
183 {
184 if (errno == ENOENT)
185 {
186 if (mkdir (orig_dir, 0755) == -1)
187 {
188 char errbuf[1024];
189 ERROR ("change_basedir: mkdir (%s): %s", orig_dir,
190 sstrerror (errno, errbuf,
191 sizeof (errbuf)));
192 return (-1);
193 }
194 else if (chdir (orig_dir) == -1)
195 {
196 char errbuf[1024];
197 ERROR ("chdir (%s): %s", orig_dir,
198 sstrerror (errno, errbuf,
199 sizeof (errbuf)));
200 return (-1);
201 }
202 }
203 else
204 {
205 char errbuf[1024];
206 ERROR ("chdir (%s): %s", orig_dir,
207 sstrerror (errno, errbuf,
208 sizeof (errbuf)));
209 return (-1);
210 }
211 }
213 return (0);
214 } /* static int change_basedir (char *dir) */
216 #if HAVE_LIBKSTAT
217 static void update_kstat (void)
218 {
219 if (kc == NULL)
220 {
221 if ((kc = kstat_open ()) == NULL)
222 ERROR ("Unable to open kstat control structure");
223 }
224 else
225 {
226 kid_t kid;
227 kid = kstat_chain_update (kc);
228 if (kid > 0)
229 {
230 INFO ("kstat chain has been updated");
231 plugin_init_all ();
232 }
233 else if (kid < 0)
234 ERROR ("kstat chain update failed");
235 /* else: everything works as expected */
236 }
238 return;
239 } /* static void update_kstat (void) */
240 #endif /* HAVE_LIBKSTAT */
242 /* TODO
243 * Remove all settings but `-f' and `-C'
244 */
245 static void exit_usage (void)
246 {
247 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
249 "Available options:\n"
250 " General:\n"
251 " -C <file> Configuration file.\n"
252 " Default: "CONFIGFILE"\n"
253 " -t Test config and exit.\n"
254 " -P <file> PID-file.\n"
255 " Default: "PIDFILE"\n"
256 #if COLLECT_DAEMON
257 " -f Don't fork to the background.\n"
258 #endif
259 " -h Display help (this message)\n"
260 "\nBuiltin defaults:\n"
261 " Config-File "CONFIGFILE"\n"
262 " PID-File "PIDFILE"\n"
263 " Data-Directory "PKGLOCALSTATEDIR"\n"
264 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
265 "by Florian octo Forster <octo@verplant.org>\n"
266 "for contributions see `AUTHORS'\n");
267 exit (0);
268 } /* static void exit_usage (char *name) */
270 static int do_init (void)
271 {
272 #if HAVE_LIBKSTAT
273 kc = NULL;
274 update_kstat ();
275 #endif
277 #if HAVE_LIBSTATGRAB
278 if (sg_init ())
279 {
280 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
281 return (-1);
282 }
284 if (sg_drop_privileges ())
285 {
286 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
287 return (-1);
288 }
289 #endif
291 plugin_init_all ();
293 return (0);
294 } /* int do_init () */
297 static int do_loop (void)
298 {
299 struct timeval tv_now;
300 struct timeval tv_next;
301 struct timespec ts_wait;
303 while (loop == 0)
304 {
305 if (gettimeofday (&tv_next, NULL) < 0)
306 {
307 char errbuf[1024];
308 ERROR ("gettimeofday failed: %s",
309 sstrerror (errno, errbuf,
310 sizeof (errbuf)));
311 return (-1);
312 }
313 tv_next.tv_sec += interval_g;
315 #if HAVE_LIBKSTAT
316 update_kstat ();
317 #endif
319 /* Issue all plugins */
320 plugin_read_all ();
322 if (gettimeofday (&tv_now, NULL) < 0)
323 {
324 char errbuf[1024];
325 ERROR ("gettimeofday failed: %s",
326 sstrerror (errno, errbuf,
327 sizeof (errbuf)));
328 return (-1);
329 }
331 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
332 {
333 WARNING ("Not sleeping because "
334 "`timeval_sub_timespec' returned "
335 "non-zero!");
336 continue;
337 }
339 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
340 {
341 if (errno != EINTR)
342 {
343 char errbuf[1024];
344 ERROR ("nanosleep failed: %s",
345 sstrerror (errno, errbuf,
346 sizeof (errbuf)));
347 return (-1);
348 }
349 }
350 } /* while (loop == 0) */
352 DEBUG ("return (0);");
353 return (0);
354 } /* int do_loop */
356 static int do_shutdown (void)
357 {
358 plugin_shutdown_all ();
359 return (0);
360 } /* int do_shutdown */
362 #if COLLECT_DAEMON
363 static int pidfile_create (void)
364 {
365 FILE *fh;
366 const char *file = global_option_get ("PIDFile");
368 if ((fh = fopen (file, "w")) == NULL)
369 {
370 char errbuf[1024];
371 ERROR ("fopen (%s): %s", file,
372 sstrerror (errno, errbuf, sizeof (errbuf)));
373 return (1);
374 }
376 fprintf (fh, "%i\n", (int) getpid ());
377 fclose(fh);
379 return (0);
380 } /* static int pidfile_create (const char *file) */
382 static int pidfile_remove (void)
383 {
384 const char *file = global_option_get ("PIDFile");
386 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
387 return (unlink (file));
388 } /* static int pidfile_remove (const char *file) */
389 #endif /* COLLECT_DAEMON */
391 int main (int argc, char **argv)
392 {
393 struct sigaction sig_int_action;
394 struct sigaction sig_term_action;
395 struct sigaction sig_usr1_action;
396 char *configfile = CONFIGFILE;
397 int test_config = 0;
398 const char *basedir;
399 #if COLLECT_DAEMON
400 struct sigaction sigChldAction;
401 pid_t pid;
402 int daemonize = 1;
403 #endif
405 /* read options */
406 while (1)
407 {
408 int c;
410 c = getopt (argc, argv, "htC:"
411 #if COLLECT_DAEMON
412 "fP:"
413 #endif
414 );
416 if (c == -1)
417 break;
419 switch (c)
420 {
421 case 'C':
422 configfile = optarg;
423 break;
424 case 't':
425 test_config = 1;
426 break;
427 #if COLLECT_DAEMON
428 case 'P':
429 global_option_set ("PIDFile", optarg);
430 break;
431 case 'f':
432 daemonize = 0;
433 break;
434 #endif /* COLLECT_DAEMON */
435 case 'h':
436 default:
437 exit_usage ();
438 } /* switch (c) */
439 } /* while (1) */
441 /*
442 * Read options from the config file, the environment and the command
443 * line (in that order, with later options overwriting previous ones in
444 * general).
445 * Also, this will automatically load modules.
446 */
447 if (cf_read (configfile))
448 {
449 fprintf (stderr, "Error: Reading the config file failed!\n"
450 "Read the syslog for details.\n");
451 return (1);
452 }
454 /*
455 * Change directory. We do this _after_ reading the config and loading
456 * modules to relative paths work as expected.
457 */
458 if ((basedir = global_option_get ("BaseDir")) == NULL)
459 {
460 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
461 return (1);
462 }
463 else if (change_basedir (basedir))
464 {
465 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
466 return (1);
467 }
469 /*
470 * Set global variables or, if that failes, exit. We cannot run with
471 * them being uninitialized. If nothing is configured, then defaults
472 * are being used. So this means that the user has actually done
473 * something wrong.
474 */
475 if (init_global_variables () != 0)
476 return (1);
478 if (test_config)
479 return (0);
481 #if COLLECT_DAEMON
482 /*
483 * fork off child
484 */
485 memset (&sigChldAction, '\0', sizeof (sigChldAction));
486 sigChldAction.sa_handler = SIG_IGN;
487 sigaction (SIGCHLD, &sigChldAction, NULL);
489 if (daemonize)
490 {
491 if ((pid = fork ()) == -1)
492 {
493 /* error */
494 char errbuf[1024];
495 fprintf (stderr, "fork: %s",
496 sstrerror (errno, errbuf,
497 sizeof (errbuf)));
498 return (1);
499 }
500 else if (pid != 0)
501 {
502 /* parent */
503 /* printf ("Running (PID %i)\n", pid); */
504 return (0);
505 }
507 /* Detach from session */
508 setsid ();
510 /* Write pidfile */
511 if (pidfile_create ())
512 exit (2);
514 /* close standard descriptors */
515 close (2);
516 close (1);
517 close (0);
519 if (open ("/dev/null", O_RDWR) != 0)
520 {
521 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
522 return (1);
523 }
524 if (dup (0) != 1)
525 {
526 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
527 return (1);
528 }
529 if (dup (0) != 2)
530 {
531 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
532 return (1);
533 }
534 } /* if (daemonize) */
535 #endif /* COLLECT_DAEMON */
537 /*
538 * install signal handlers
539 */
540 memset (&sig_int_action, '\0', sizeof (sig_int_action));
541 sig_int_action.sa_handler = sig_int_handler;
542 if (0 != sigaction (SIGINT, &sig_int_action, NULL)) {
543 char errbuf[1024];
544 ERROR ("Error: Failed to install a signal handler for signal INT: %s",
545 sstrerror (errno, errbuf, sizeof (errbuf)));
546 return (1);
547 }
549 memset (&sig_term_action, '\0', sizeof (sig_term_action));
550 sig_term_action.sa_handler = sig_term_handler;
551 if (0 != sigaction (SIGTERM, &sig_term_action, NULL)) {
552 char errbuf[1024];
553 ERROR ("Error: Failed to install a signal handler for signal TERM: %s",
554 sstrerror (errno, errbuf, sizeof (errbuf)));
555 return (1);
556 }
558 memset (&sig_usr1_action, '\0', sizeof (sig_usr1_action));
559 sig_usr1_action.sa_handler = sig_usr1_handler;
560 if (0 != sigaction (SIGUSR1, &sig_usr1_action, NULL)) {
561 char errbuf[1024];
562 ERROR ("Error: Failed to install a signal handler for signal USR1: %s",
563 sstrerror (errno, errbuf, sizeof (errbuf)));
564 return (1);
565 }
567 /*
568 * run the actual loops
569 */
570 do_init ();
571 do_loop ();
573 /* close syslog */
574 INFO ("Exiting normally");
576 do_shutdown ();
578 #if COLLECT_DAEMON
579 if (daemonize)
580 pidfile_remove ();
581 #endif /* COLLECT_DAEMON */
583 return (0);
584 } /* int main */