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 "plugin.h"
32 #include "configfile.h"
34 #include <sys/types.h>
35 #include <sys/socket.h>
36 #include <sys/un.h>
37 #include <netdb.h>
39 #include <pthread.h>
41 #if HAVE_LOCALE_H
42 # include <locale.h>
43 #endif
45 #if HAVE_STATGRAB_H
46 # include <statgrab.h>
47 #endif
49 #ifndef COLLECTD_LOCALE
50 # define COLLECTD_LOCALE "C"
51 #endif
53 /*
54 * Global variables
55 */
56 char hostname_g[DATA_MAX_NAME_LEN];
57 cdtime_t interval_g;
58 int pidfile_from_cli = 0;
59 int timeout_g;
60 #if HAVE_LIBKSTAT
61 kstat_ctl_t *kc;
62 #endif /* HAVE_LIBKSTAT */
64 static int loop = 0;
66 static void *do_flush (void __attribute__((unused)) *arg)
67 {
68 INFO ("Flushing all data.");
69 plugin_flush (/* plugin = */ NULL,
70 /* timeout = */ 0,
71 /* ident = */ NULL);
72 INFO ("Finished flushing all data.");
73 pthread_exit (NULL);
74 return NULL;
75 }
77 static void sig_int_handler (int __attribute__((unused)) signal)
78 {
79 loop++;
80 }
82 static void sig_term_handler (int __attribute__((unused)) signal)
83 {
84 loop++;
85 }
87 static void sig_usr1_handler (int __attribute__((unused)) signal)
88 {
89 pthread_t thread;
90 pthread_attr_t attr;
92 /* flushing the data might take a while,
93 * so it should be done asynchronously */
94 pthread_attr_init (&attr);
95 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
96 pthread_create (&thread, &attr, do_flush, NULL);
97 pthread_attr_destroy (&attr);
98 }
100 static int init_hostname (void)
101 {
102 const char *str;
104 struct addrinfo ai_hints;
105 struct addrinfo *ai_list;
106 struct addrinfo *ai_ptr;
107 int status;
109 str = global_option_get ("Hostname");
110 if (str != NULL)
111 {
112 sstrncpy (hostname_g, str, sizeof (hostname_g));
113 return (0);
114 }
116 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
117 {
118 fprintf (stderr, "`gethostname' failed and no "
119 "hostname was configured.\n");
120 return (-1);
121 }
123 str = global_option_get ("FQDNLookup");
124 if (IS_FALSE (str))
125 return (0);
127 memset (&ai_hints, '\0', sizeof (ai_hints));
128 ai_hints.ai_flags = AI_CANONNAME;
130 status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
131 if (status != 0)
132 {
133 ERROR ("Looking up \"%s\" failed. You have set the "
134 "\"FQDNLookup\" option, but I cannot resolve "
135 "my hostname to a fully qualified domain "
136 "name. Please fix the network "
137 "configuration.", hostname_g);
138 return (-1);
139 }
141 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
142 {
143 if (ai_ptr->ai_canonname == NULL)
144 continue;
146 sstrncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
147 break;
148 }
150 freeaddrinfo (ai_list);
151 return (0);
152 } /* int init_hostname */
154 static int init_global_variables (void)
155 {
156 char const *str;
158 interval_g = cf_get_default_interval ();
159 assert (interval_g > 0);
160 DEBUG ("interval_g = %.3f;", CDTIME_T_TO_DOUBLE (interval_g));
162 str = global_option_get ("Timeout");
163 if (str == NULL)
164 str = "2";
165 timeout_g = atoi (str);
166 if (timeout_g <= 1)
167 {
168 fprintf (stderr, "Cannot set the timeout to a correct value.\n"
169 "Please check your settings.\n");
170 return (-1);
171 }
172 DEBUG ("timeout_g = %i;", timeout_g);
174 if (init_hostname () != 0)
175 return (-1);
176 DEBUG ("hostname_g = %s;", hostname_g);
178 return (0);
179 } /* int init_global_variables */
181 static int change_basedir (const char *orig_dir)
182 {
183 char *dir;
184 size_t dirlen;
185 int status;
187 dir = strdup (orig_dir);
188 if (dir == NULL)
189 {
190 char errbuf[1024];
191 ERROR ("strdup failed: %s",
192 sstrerror (errno, errbuf, sizeof (errbuf)));
193 return (-1);
194 }
196 dirlen = strlen (dir);
197 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
198 dir[--dirlen] = '\0';
200 if (dirlen <= 0)
201 return (-1);
203 status = chdir (dir);
204 if (status == 0)
205 {
206 free (dir);
207 return (0);
208 }
209 else if (errno != ENOENT)
210 {
211 char errbuf[1024];
212 ERROR ("change_basedir: chdir (%s): %s", dir,
213 sstrerror (errno, errbuf, sizeof (errbuf)));
214 free (dir);
215 return (-1);
216 }
218 status = mkdir (dir, S_IRWXU | S_IRWXG | S_IRWXO);
219 if (status != 0)
220 {
221 char errbuf[1024];
222 ERROR ("change_basedir: mkdir (%s): %s", dir,
223 sstrerror (errno, errbuf, sizeof (errbuf)));
224 free (dir);
225 return (-1);
226 }
228 status = chdir (dir);
229 if (status != 0)
230 {
231 char errbuf[1024];
232 ERROR ("change_basedir: chdir (%s): %s", dir,
233 sstrerror (errno, errbuf, sizeof (errbuf)));
234 free (dir);
235 return (-1);
236 }
238 free (dir);
239 return (0);
240 } /* static int change_basedir (char *dir) */
242 #if HAVE_LIBKSTAT
243 static void update_kstat (void)
244 {
245 if (kc == NULL)
246 {
247 if ((kc = kstat_open ()) == NULL)
248 ERROR ("Unable to open kstat control structure");
249 }
250 else
251 {
252 kid_t kid;
253 kid = kstat_chain_update (kc);
254 if (kid > 0)
255 {
256 INFO ("kstat chain has been updated");
257 plugin_init_all ();
258 }
259 else if (kid < 0)
260 ERROR ("kstat chain update failed");
261 /* else: everything works as expected */
262 }
264 return;
265 } /* static void update_kstat (void) */
266 #endif /* HAVE_LIBKSTAT */
268 /* TODO
269 * Remove all settings but `-f' and `-C'
270 */
271 static void exit_usage (int status)
272 {
273 printf ("Usage: "PACKAGE_NAME" [OPTIONS]\n\n"
275 "Available options:\n"
276 " General:\n"
277 " -C <file> Configuration file.\n"
278 " Default: "CONFIGFILE"\n"
279 " -t Test config and exit.\n"
280 " -T Test plugin read and exit.\n"
281 " -P <file> PID-file.\n"
282 " Default: "PIDFILE"\n"
283 #if COLLECT_DAEMON
284 " -f Don't fork to the background.\n"
285 #endif
286 " -h Display help (this message)\n"
287 "\nBuiltin defaults:\n"
288 " Config file "CONFIGFILE"\n"
289 " PID file "PIDFILE"\n"
290 " Plugin directory "PLUGINDIR"\n"
291 " Data directory "PKGLOCALSTATEDIR"\n"
292 "\n"PACKAGE_NAME" "PACKAGE_VERSION", http://collectd.org/\n"
293 "by Florian octo Forster <octo@collectd.org>\n"
294 "for contributions see `AUTHORS'\n");
295 exit (status);
296 } /* static void exit_usage (int status) */
298 static int do_init (void)
299 {
300 #if HAVE_SETLOCALE
301 if (setlocale (LC_NUMERIC, COLLECTD_LOCALE) == NULL)
302 WARNING ("setlocale (\"%s\") failed.", COLLECTD_LOCALE);
303 #endif
305 #if HAVE_LIBKSTAT
306 kc = NULL;
307 update_kstat ();
308 #endif
310 #if HAVE_LIBSTATGRAB
311 if (sg_init (
312 # if HAVE_LIBSTATGRAB_0_90
313 0
314 # endif
315 ))
316 {
317 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
318 return (-1);
319 }
321 if (sg_drop_privileges ())
322 {
323 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
324 return (-1);
325 }
326 #endif
328 plugin_init_all ();
330 return (0);
331 } /* int do_init () */
334 static int do_loop (void)
335 {
336 cdtime_t interval = cf_get_default_interval ();
337 cdtime_t wait_until;
339 wait_until = cdtime () + interval;
341 while (loop == 0)
342 {
343 struct timespec ts_wait = { 0, 0 };
344 cdtime_t now;
346 #if HAVE_LIBKSTAT
347 update_kstat ();
348 #endif
350 /* Issue all plugins */
351 plugin_read_all ();
353 now = cdtime ();
354 if (now >= wait_until)
355 {
356 WARNING ("Not sleeping because the next interval is "
357 "%.3f seconds in the past!",
358 CDTIME_T_TO_DOUBLE (now - wait_until));
359 wait_until = now + interval;
360 continue;
361 }
363 CDTIME_T_TO_TIMESPEC (wait_until - now, &ts_wait);
364 wait_until = wait_until + interval;
366 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) != 0))
367 {
368 if (errno != EINTR)
369 {
370 char errbuf[1024];
371 ERROR ("nanosleep failed: %s",
372 sstrerror (errno, errbuf,
373 sizeof (errbuf)));
374 return (-1);
375 }
376 }
377 } /* while (loop == 0) */
379 return (0);
380 } /* int do_loop */
382 static int do_shutdown (void)
383 {
384 plugin_shutdown_all ();
385 return (0);
386 } /* int do_shutdown */
388 #if COLLECT_DAEMON
389 static int pidfile_create (void)
390 {
391 FILE *fh;
392 const char *file = global_option_get ("PIDFile");
394 if ((fh = fopen (file, "w")) == NULL)
395 {
396 char errbuf[1024];
397 ERROR ("fopen (%s): %s", file,
398 sstrerror (errno, errbuf, sizeof (errbuf)));
399 return (1);
400 }
402 fprintf (fh, "%i\n", (int) getpid ());
403 fclose(fh);
405 return (0);
406 } /* static int pidfile_create (const char *file) */
408 static int pidfile_remove (void)
409 {
410 const char *file = global_option_get ("PIDFile");
411 if (file == NULL)
412 return 0;
414 return (unlink (file));
415 } /* static int pidfile_remove (const char *file) */
416 #endif /* COLLECT_DAEMON */
418 #ifdef KERNEL_LINUX
419 int notify_upstart (void)
420 {
421 const char *upstart_job = getenv("UPSTART_JOB");
423 if (upstart_job == NULL)
424 return 0;
426 if (strcmp(upstart_job, "collectd") != 0)
427 return 0;
429 WARNING ("supervised by upstart, will stop to signal readyness");
430 raise(SIGSTOP);
431 unsetenv("UPSTART_JOB");
433 return 1;
434 }
436 int notify_systemd (void)
437 {
438 int fd = -1;
439 const char *notifysocket = getenv("NOTIFY_SOCKET");
440 struct sockaddr_un su;
441 struct iovec iov;
442 struct msghdr hdr;
444 if (notifysocket == NULL)
445 return 0;
447 if ((strchr("@/", notifysocket[0])) == NULL ||
448 strlen(notifysocket) < 2)
449 return 0;
451 WARNING ("supervised by systemd, will signal readyness");
452 if ((fd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) {
453 WARNING ("cannot contact systemd socket %s", notifysocket);
454 return 0;
455 }
457 bzero(&su, sizeof(su));
458 su.sun_family = AF_UNIX;
459 sstrncpy (su.sun_path, notifysocket, sizeof(su.sun_path));
461 if (notifysocket[0] == '@')
462 su.sun_path[0] = 0;
464 bzero(&iov, sizeof(iov));
465 iov.iov_base = "READY=1";
466 iov.iov_len = strlen("READY=1");
468 bzero(&hdr, sizeof(hdr));
469 hdr.msg_name = &su;
470 hdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) +
471 strlen(notifysocket);
472 hdr.msg_iov = &iov;
473 hdr.msg_iovlen = 1;
475 unsetenv("NOTIFY_SOCKET");
476 if (sendmsg(fd, &hdr, MSG_NOSIGNAL) < 0) {
477 WARNING ("cannot send notification to systemd");
478 close(fd);
479 return 0;
480 }
481 close(fd);
482 return 1;
483 }
484 #endif /* KERNEL_LINUX */
486 int main (int argc, char **argv)
487 {
488 struct sigaction sig_int_action;
489 struct sigaction sig_term_action;
490 struct sigaction sig_usr1_action;
491 struct sigaction sig_pipe_action;
492 char *configfile = CONFIGFILE;
493 int test_config = 0;
494 int test_readall = 0;
495 const char *basedir;
496 #if COLLECT_DAEMON
497 struct sigaction sig_chld_action;
498 pid_t pid;
499 int daemonize = 1;
500 #endif
501 int exit_status = 0;
503 /* read options */
504 while (1)
505 {
506 int c;
508 c = getopt (argc, argv, "htTC:"
509 #if COLLECT_DAEMON
510 "fP:"
511 #endif
512 );
514 if (c == -1)
515 break;
517 switch (c)
518 {
519 case 'C':
520 configfile = optarg;
521 break;
522 case 't':
523 test_config = 1;
524 break;
525 case 'T':
526 test_readall = 1;
527 global_option_set ("ReadThreads", "-1");
528 #if COLLECT_DAEMON
529 daemonize = 0;
530 #endif /* COLLECT_DAEMON */
531 break;
532 #if COLLECT_DAEMON
533 case 'P':
534 global_option_set ("PIDFile", optarg);
535 pidfile_from_cli = 1;
536 break;
537 case 'f':
538 daemonize = 0;
539 break;
540 #endif /* COLLECT_DAEMON */
541 case 'h':
542 exit_usage (0);
543 break;
544 default:
545 exit_usage (1);
546 } /* switch (c) */
547 } /* while (1) */
549 if (optind < argc)
550 exit_usage (1);
552 plugin_init_ctx ();
554 /*
555 * Read options from the config file, the environment and the command
556 * line (in that order, with later options overwriting previous ones in
557 * general).
558 * Also, this will automatically load modules.
559 */
560 if (cf_read (configfile))
561 {
562 fprintf (stderr, "Error: Reading the config file failed!\n"
563 "Read the syslog for details.\n");
564 return (1);
565 }
567 /*
568 * Change directory. We do this _after_ reading the config and loading
569 * modules to relative paths work as expected.
570 */
571 if ((basedir = global_option_get ("BaseDir")) == NULL)
572 {
573 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
574 return (1);
575 }
576 else if (change_basedir (basedir))
577 {
578 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
579 return (1);
580 }
582 /*
583 * Set global variables or, if that failes, exit. We cannot run with
584 * them being uninitialized. If nothing is configured, then defaults
585 * are being used. So this means that the user has actually done
586 * something wrong.
587 */
588 if (init_global_variables () != 0)
589 return (1);
591 if (test_config)
592 return (0);
594 #if COLLECT_DAEMON
595 /*
596 * fork off child
597 */
598 memset (&sig_chld_action, '\0', sizeof (sig_chld_action));
599 sig_chld_action.sa_handler = SIG_IGN;
600 sigaction (SIGCHLD, &sig_chld_action, NULL);
602 /*
603 * Only daemonize if we're not being supervised
604 * by upstart or systemd (when using Linux).
605 */
606 if (daemonize
607 #ifdef KERNEL_LINUX
608 && notify_upstart() == 0 && notify_systemd() == 0
609 #endif
610 )
611 {
612 if ((pid = fork ()) == -1)
613 {
614 /* error */
615 char errbuf[1024];
616 fprintf (stderr, "fork: %s",
617 sstrerror (errno, errbuf,
618 sizeof (errbuf)));
619 return (1);
620 }
621 else if (pid != 0)
622 {
623 /* parent */
624 /* printf ("Running (PID %i)\n", pid); */
625 return (0);
626 }
628 /* Detach from session */
629 setsid ();
631 /* Write pidfile */
632 if (pidfile_create ())
633 exit (2);
635 /* close standard descriptors */
636 close (2);
637 close (1);
638 close (0);
640 if (open ("/dev/null", O_RDWR) != 0)
641 {
642 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
643 return (1);
644 }
645 if (dup (0) != 1)
646 {
647 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
648 return (1);
649 }
650 if (dup (0) != 2)
651 {
652 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
653 return (1);
654 }
655 } /* if (daemonize) */
656 #endif /* COLLECT_DAEMON */
658 memset (&sig_pipe_action, '\0', sizeof (sig_pipe_action));
659 sig_pipe_action.sa_handler = SIG_IGN;
660 sigaction (SIGPIPE, &sig_pipe_action, NULL);
662 /*
663 * install signal handlers
664 */
665 memset (&sig_int_action, '\0', sizeof (sig_int_action));
666 sig_int_action.sa_handler = sig_int_handler;
667 if (0 != sigaction (SIGINT, &sig_int_action, NULL)) {
668 char errbuf[1024];
669 ERROR ("Error: Failed to install a signal handler for signal INT: %s",
670 sstrerror (errno, errbuf, sizeof (errbuf)));
671 return (1);
672 }
674 memset (&sig_term_action, '\0', sizeof (sig_term_action));
675 sig_term_action.sa_handler = sig_term_handler;
676 if (0 != sigaction (SIGTERM, &sig_term_action, NULL)) {
677 char errbuf[1024];
678 ERROR ("Error: Failed to install a signal handler for signal TERM: %s",
679 sstrerror (errno, errbuf, sizeof (errbuf)));
680 return (1);
681 }
683 memset (&sig_usr1_action, '\0', sizeof (sig_usr1_action));
684 sig_usr1_action.sa_handler = sig_usr1_handler;
685 if (0 != sigaction (SIGUSR1, &sig_usr1_action, NULL)) {
686 char errbuf[1024];
687 ERROR ("Error: Failed to install a signal handler for signal USR1: %s",
688 sstrerror (errno, errbuf, sizeof (errbuf)));
689 return (1);
690 }
692 /*
693 * run the actual loops
694 */
695 do_init ();
697 if (test_readall)
698 {
699 if (plugin_read_all_once () != 0)
700 exit_status = 1;
701 }
702 else
703 {
704 INFO ("Initialization complete, entering read-loop.");
705 do_loop ();
706 }
708 /* close syslog */
709 INFO ("Exiting normally.");
711 do_shutdown ();
713 #if COLLECT_DAEMON
714 if (daemonize)
715 pidfile_remove ();
716 #endif /* COLLECT_DAEMON */
718 return (exit_status);
719 } /* int main */