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 free (dir);
202 return (-1);
203 }
205 status = chdir (dir);
206 if (status == 0)
207 {
208 free (dir);
209 return (0);
210 }
211 else if (errno != ENOENT)
212 {
213 char errbuf[1024];
214 ERROR ("change_basedir: chdir (%s): %s", dir,
215 sstrerror (errno, errbuf, sizeof (errbuf)));
216 free (dir);
217 return (-1);
218 }
220 status = mkdir (dir, S_IRWXU | S_IRWXG | S_IRWXO);
221 if (status != 0)
222 {
223 char errbuf[1024];
224 ERROR ("change_basedir: mkdir (%s): %s", dir,
225 sstrerror (errno, errbuf, sizeof (errbuf)));
226 free (dir);
227 return (-1);
228 }
230 status = chdir (dir);
231 if (status != 0)
232 {
233 char errbuf[1024];
234 ERROR ("change_basedir: chdir (%s): %s", dir,
235 sstrerror (errno, errbuf, sizeof (errbuf)));
236 free (dir);
237 return (-1);
238 }
240 free (dir);
241 return (0);
242 } /* static int change_basedir (char *dir) */
244 #if HAVE_LIBKSTAT
245 static void update_kstat (void)
246 {
247 if (kc == NULL)
248 {
249 if ((kc = kstat_open ()) == NULL)
250 ERROR ("Unable to open kstat control structure");
251 }
252 else
253 {
254 kid_t kid;
255 kid = kstat_chain_update (kc);
256 if (kid > 0)
257 {
258 INFO ("kstat chain has been updated");
259 plugin_init_all ();
260 }
261 else if (kid < 0)
262 ERROR ("kstat chain update failed");
263 /* else: everything works as expected */
264 }
266 return;
267 } /* static void update_kstat (void) */
268 #endif /* HAVE_LIBKSTAT */
270 /* TODO
271 * Remove all settings but `-f' and `-C'
272 */
273 static void exit_usage (int status)
274 {
275 printf ("Usage: "PACKAGE_NAME" [OPTIONS]\n\n"
277 "Available options:\n"
278 " General:\n"
279 " -C <file> Configuration file.\n"
280 " Default: "CONFIGFILE"\n"
281 " -t Test config and exit.\n"
282 " -T Test plugin read and exit.\n"
283 " -P <file> PID-file.\n"
284 " Default: "PIDFILE"\n"
285 #if COLLECT_DAEMON
286 " -f Don't fork to the background.\n"
287 #endif
288 " -h Display help (this message)\n"
289 "\nBuiltin defaults:\n"
290 " Config file "CONFIGFILE"\n"
291 " PID file "PIDFILE"\n"
292 " Plugin directory "PLUGINDIR"\n"
293 " Data directory "PKGLOCALSTATEDIR"\n"
294 "\n"PACKAGE_NAME" "PACKAGE_VERSION", http://collectd.org/\n"
295 "by Florian octo Forster <octo@collectd.org>\n"
296 "for contributions see `AUTHORS'\n");
297 exit (status);
298 } /* static void exit_usage (int status) */
300 static int do_init (void)
301 {
302 #if HAVE_SETLOCALE
303 if (setlocale (LC_NUMERIC, COLLECTD_LOCALE) == NULL)
304 WARNING ("setlocale (\"%s\") failed.", COLLECTD_LOCALE);
305 #endif
307 #if HAVE_LIBKSTAT
308 kc = NULL;
309 update_kstat ();
310 #endif
312 #if HAVE_LIBSTATGRAB
313 if (sg_init (
314 # if HAVE_LIBSTATGRAB_0_90
315 0
316 # endif
317 ))
318 {
319 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
320 return (-1);
321 }
323 if (sg_drop_privileges ())
324 {
325 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
326 return (-1);
327 }
328 #endif
330 plugin_init_all ();
332 return (0);
333 } /* int do_init () */
336 static int do_loop (void)
337 {
338 cdtime_t interval = cf_get_default_interval ();
339 cdtime_t wait_until;
341 wait_until = cdtime () + interval;
343 while (loop == 0)
344 {
345 struct timespec ts_wait = { 0, 0 };
346 cdtime_t now;
348 #if HAVE_LIBKSTAT
349 update_kstat ();
350 #endif
352 /* Issue all plugins */
353 plugin_read_all ();
355 now = cdtime ();
356 if (now >= wait_until)
357 {
358 WARNING ("Not sleeping because the next interval is "
359 "%.3f seconds in the past!",
360 CDTIME_T_TO_DOUBLE (now - wait_until));
361 wait_until = now + interval;
362 continue;
363 }
365 CDTIME_T_TO_TIMESPEC (wait_until - now, &ts_wait);
366 wait_until = wait_until + interval;
368 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) != 0))
369 {
370 if (errno != EINTR)
371 {
372 char errbuf[1024];
373 ERROR ("nanosleep failed: %s",
374 sstrerror (errno, errbuf,
375 sizeof (errbuf)));
376 return (-1);
377 }
378 }
379 } /* while (loop == 0) */
381 return (0);
382 } /* int do_loop */
384 static int do_shutdown (void)
385 {
386 plugin_shutdown_all ();
387 return (0);
388 } /* int do_shutdown */
390 #if COLLECT_DAEMON
391 static int pidfile_create (void)
392 {
393 FILE *fh;
394 const char *file = global_option_get ("PIDFile");
396 if ((fh = fopen (file, "w")) == NULL)
397 {
398 char errbuf[1024];
399 ERROR ("fopen (%s): %s", file,
400 sstrerror (errno, errbuf, sizeof (errbuf)));
401 return (1);
402 }
404 fprintf (fh, "%i\n", (int) getpid ());
405 fclose(fh);
407 return (0);
408 } /* static int pidfile_create (const char *file) */
410 static int pidfile_remove (void)
411 {
412 const char *file = global_option_get ("PIDFile");
413 if (file == NULL)
414 return 0;
416 return (unlink (file));
417 } /* static int pidfile_remove (const char *file) */
418 #endif /* COLLECT_DAEMON */
420 #ifdef KERNEL_LINUX
421 int notify_upstart (void)
422 {
423 char const *upstart_job = getenv("UPSTART_JOB");
425 if (upstart_job == NULL)
426 return 0;
428 if (strcmp(upstart_job, "collectd") != 0)
429 {
430 WARNING ("Environment specifies unexpected UPSTART_JOB=\"%s\", expected \"collectd\". Ignoring the variable.", upstart_job);
431 return 0;
432 }
434 NOTICE("Upstart detected, stopping now to signal readyness.");
435 raise(SIGSTOP);
436 unsetenv("UPSTART_JOB");
438 return 1;
439 }
441 int notify_systemd (void)
442 {
443 int fd;
444 const char *notifysocket;
445 struct sockaddr_un su;
446 size_t su_size;
447 char buffer[] = "READY=1\n";
449 notifysocket = getenv ("NOTIFY_SOCKET");
450 if (notifysocket == NULL)
451 return 0;
453 if ((strlen (notifysocket) < 2)
454 || ((notifysocket[0] != '@') && (notifysocket[0] != '/')))
455 {
456 ERROR ("invalid notification socket NOTIFY_SOCKET=\"%s\": path must be absolute", notifysocket);
457 return 0;
458 }
459 NOTICE ("Systemd detected, trying to signal readyness.");
461 unsetenv ("NOTIFY_SOCKET");
463 fd = socket (AF_UNIX, SOCK_DGRAM, /* protocol = */ 0);
464 if (fd < 0) {
465 char errbuf[1024];
466 ERROR ("creating UNIX socket failed: %s",
467 sstrerror (errno, errbuf, sizeof (errbuf)));
468 return 0;
469 }
471 memset (&su, 0, sizeof (su));
472 su.sun_family = AF_UNIX;
473 if (notifysocket[0] != '@')
474 {
475 /* regular UNIX socket */
476 sstrncpy (su.sun_path, notifysocket, sizeof (su.sun_path));
477 su_size = sizeof (su);
478 }
479 else
480 {
481 #if KERNEL_LINUX
482 /* Linux abstract namespace socket: specify address as "\0foo", i.e.
483 * start with a null byte. Since null bytes have no special meaning in
484 * that case, we have to set su_size correctly to cover only the bytes
485 * that are part of the address. */
486 sstrncpy (su.sun_path, notifysocket, sizeof (su.sun_path));
487 su.sun_path[0] = 0;
488 su_size = sizeof (sa_family_t) + strlen (notifysocket);
489 if (su_size > sizeof (su))
490 su_size = sizeof (su);
491 #else
492 ERROR ("Systemd socket uses Linux abstract namespace notation (\"%s\"), "
493 "but I don't appear to be running on Linux.", notifysocket);
494 return 0;
495 #endif
496 }
498 if (sendto (fd, buffer, strlen (buffer), MSG_NOSIGNAL, (void *) &su, (socklen_t) su_size) < 0)
499 {
500 char errbuf[1024];
501 ERROR ("sendto(\"%s\") failed: %s", notifysocket,
502 sstrerror (errno, errbuf, sizeof (errbuf)));
503 close(fd);
504 return 0;
505 }
507 close(fd);
508 return 1;
509 }
510 #endif /* KERNEL_LINUX */
512 int main (int argc, char **argv)
513 {
514 struct sigaction sig_int_action;
515 struct sigaction sig_term_action;
516 struct sigaction sig_usr1_action;
517 struct sigaction sig_pipe_action;
518 char *configfile = CONFIGFILE;
519 int test_config = 0;
520 int test_readall = 0;
521 const char *basedir;
522 #if COLLECT_DAEMON
523 struct sigaction sig_chld_action;
524 pid_t pid;
525 int daemonize = 1;
526 #endif
527 int exit_status = 0;
529 /* read options */
530 while (1)
531 {
532 int c;
534 c = getopt (argc, argv, "htTC:"
535 #if COLLECT_DAEMON
536 "fP:"
537 #endif
538 );
540 if (c == -1)
541 break;
543 switch (c)
544 {
545 case 'C':
546 configfile = optarg;
547 break;
548 case 't':
549 test_config = 1;
550 break;
551 case 'T':
552 test_readall = 1;
553 global_option_set ("ReadThreads", "-1");
554 #if COLLECT_DAEMON
555 daemonize = 0;
556 #endif /* COLLECT_DAEMON */
557 break;
558 #if COLLECT_DAEMON
559 case 'P':
560 global_option_set ("PIDFile", optarg);
561 pidfile_from_cli = 1;
562 break;
563 case 'f':
564 daemonize = 0;
565 break;
566 #endif /* COLLECT_DAEMON */
567 case 'h':
568 exit_usage (0);
569 break;
570 default:
571 exit_usage (1);
572 } /* switch (c) */
573 } /* while (1) */
575 if (optind < argc)
576 exit_usage (1);
578 plugin_init_ctx ();
580 /*
581 * Read options from the config file, the environment and the command
582 * line (in that order, with later options overwriting previous ones in
583 * general).
584 * Also, this will automatically load modules.
585 */
586 if (cf_read (configfile))
587 {
588 fprintf (stderr, "Error: Reading the config file failed!\n"
589 "Read the syslog for details.\n");
590 return (1);
591 }
593 /*
594 * Change directory. We do this _after_ reading the config and loading
595 * modules to relative paths work as expected.
596 */
597 if ((basedir = global_option_get ("BaseDir")) == NULL)
598 {
599 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
600 return (1);
601 }
602 else if (change_basedir (basedir))
603 {
604 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
605 return (1);
606 }
608 /*
609 * Set global variables or, if that failes, exit. We cannot run with
610 * them being uninitialized. If nothing is configured, then defaults
611 * are being used. So this means that the user has actually done
612 * something wrong.
613 */
614 if (init_global_variables () != 0)
615 return (1);
617 if (test_config)
618 return (0);
620 #if COLLECT_DAEMON
621 /*
622 * fork off child
623 */
624 memset (&sig_chld_action, '\0', sizeof (sig_chld_action));
625 sig_chld_action.sa_handler = SIG_IGN;
626 sigaction (SIGCHLD, &sig_chld_action, NULL);
628 /*
629 * Only daemonize if we're not being supervised
630 * by upstart or systemd (when using Linux).
631 */
632 if (daemonize
633 #ifdef KERNEL_LINUX
634 && notify_upstart() == 0 && notify_systemd() == 0
635 #endif
636 )
637 {
638 if ((pid = fork ()) == -1)
639 {
640 /* error */
641 char errbuf[1024];
642 fprintf (stderr, "fork: %s",
643 sstrerror (errno, errbuf,
644 sizeof (errbuf)));
645 return (1);
646 }
647 else if (pid != 0)
648 {
649 /* parent */
650 /* printf ("Running (PID %i)\n", pid); */
651 return (0);
652 }
654 /* Detach from session */
655 setsid ();
657 /* Write pidfile */
658 if (pidfile_create ())
659 exit (2);
661 /* close standard descriptors */
662 close (2);
663 close (1);
664 close (0);
666 if (open ("/dev/null", O_RDWR) != 0)
667 {
668 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
669 return (1);
670 }
671 if (dup (0) != 1)
672 {
673 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
674 return (1);
675 }
676 if (dup (0) != 2)
677 {
678 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
679 return (1);
680 }
681 } /* if (daemonize) */
682 #endif /* COLLECT_DAEMON */
684 memset (&sig_pipe_action, '\0', sizeof (sig_pipe_action));
685 sig_pipe_action.sa_handler = SIG_IGN;
686 sigaction (SIGPIPE, &sig_pipe_action, NULL);
688 /*
689 * install signal handlers
690 */
691 memset (&sig_int_action, '\0', sizeof (sig_int_action));
692 sig_int_action.sa_handler = sig_int_handler;
693 if (0 != sigaction (SIGINT, &sig_int_action, NULL)) {
694 char errbuf[1024];
695 ERROR ("Error: Failed to install a signal handler for signal INT: %s",
696 sstrerror (errno, errbuf, sizeof (errbuf)));
697 return (1);
698 }
700 memset (&sig_term_action, '\0', sizeof (sig_term_action));
701 sig_term_action.sa_handler = sig_term_handler;
702 if (0 != sigaction (SIGTERM, &sig_term_action, NULL)) {
703 char errbuf[1024];
704 ERROR ("Error: Failed to install a signal handler for signal TERM: %s",
705 sstrerror (errno, errbuf, sizeof (errbuf)));
706 return (1);
707 }
709 memset (&sig_usr1_action, '\0', sizeof (sig_usr1_action));
710 sig_usr1_action.sa_handler = sig_usr1_handler;
711 if (0 != sigaction (SIGUSR1, &sig_usr1_action, NULL)) {
712 char errbuf[1024];
713 ERROR ("Error: Failed to install a signal handler for signal USR1: %s",
714 sstrerror (errno, errbuf, sizeof (errbuf)));
715 return (1);
716 }
718 /*
719 * run the actual loops
720 */
721 do_init ();
723 if (test_readall)
724 {
725 if (plugin_read_all_once () != 0)
726 exit_status = 1;
727 }
728 else
729 {
730 INFO ("Initialization complete, entering read-loop.");
731 do_loop ();
732 }
734 /* close syslog */
735 INFO ("Exiting normally.");
737 do_shutdown ();
739 #if COLLECT_DAEMON
740 if (daemonize)
741 pidfile_remove ();
742 #endif /* COLLECT_DAEMON */
744 return (exit_status);
745 } /* int main */