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 timeout_g;
50 #if HAVE_LIBKSTAT
51 kstat_ctl_t *kc;
52 #endif /* HAVE_LIBKSTAT */
54 static int loop = 0;
56 static void *do_flush (void __attribute__((unused)) *arg)
57 {
58 INFO ("Flushing all data.");
59 plugin_flush (/* plugin = */ NULL,
60 /* timeout = */ 0,
61 /* ident = */ NULL);
62 INFO ("Finished flushing all data.");
63 pthread_exit (NULL);
64 return NULL;
65 }
67 static void sig_int_handler (int __attribute__((unused)) signal)
68 {
69 loop++;
70 }
72 static void sig_term_handler (int __attribute__((unused)) signal)
73 {
74 loop++;
75 }
77 static void sig_usr1_handler (int __attribute__((unused)) signal)
78 {
79 pthread_t thread;
80 pthread_attr_t attr;
82 /* flushing the data might take a while,
83 * so it should be done asynchronously */
84 pthread_attr_init (&attr);
85 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
86 pthread_create (&thread, &attr, do_flush, NULL);
87 pthread_attr_destroy (&attr);
88 }
90 static int init_hostname (void)
91 {
92 const char *str;
94 struct addrinfo ai_hints;
95 struct addrinfo *ai_list;
96 struct addrinfo *ai_ptr;
97 int status;
99 str = global_option_get ("Hostname");
100 if (str != NULL)
101 {
102 sstrncpy (hostname_g, str, sizeof (hostname_g));
103 return (0);
104 }
106 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
107 {
108 fprintf (stderr, "`gethostname' failed and no "
109 "hostname was configured.\n");
110 return (-1);
111 }
113 str = global_option_get ("FQDNLookup");
114 if (IS_FALSE (str))
115 return (0);
117 memset (&ai_hints, '\0', sizeof (ai_hints));
118 ai_hints.ai_flags = AI_CANONNAME;
120 status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
121 if (status != 0)
122 {
123 ERROR ("Looking up \"%s\" failed. You have set the "
124 "\"FQDNLookup\" option, but I cannot resolve "
125 "my hostname to a fully qualified domain "
126 "name. Please fix the network "
127 "configuration.", hostname_g);
128 return (-1);
129 }
131 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
132 {
133 if (ai_ptr->ai_canonname == NULL)
134 continue;
136 sstrncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
137 break;
138 }
140 freeaddrinfo (ai_list);
141 return (0);
142 } /* int init_hostname */
144 static int init_global_variables (void)
145 {
146 char const *str;
148 interval_g = cf_get_default_interval ();
149 assert (interval_g > 0);
150 DEBUG ("interval_g = %.3f;", CDTIME_T_TO_DOUBLE (interval_g));
152 str = global_option_get ("Timeout");
153 if (str == NULL)
154 str = "2";
155 timeout_g = atoi (str);
156 if (timeout_g <= 1)
157 {
158 fprintf (stderr, "Cannot set the timeout to a correct value.\n"
159 "Please check your settings.\n");
160 return (-1);
161 }
162 DEBUG ("timeout_g = %i;", timeout_g);
164 if (init_hostname () != 0)
165 return (-1);
166 DEBUG ("hostname_g = %s;", hostname_g);
168 return (0);
169 } /* int init_global_variables */
171 static int change_basedir (const char *orig_dir)
172 {
173 char *dir;
174 size_t dirlen;
175 int status;
177 dir = strdup (orig_dir);
178 if (dir == NULL)
179 {
180 char errbuf[1024];
181 ERROR ("strdup failed: %s",
182 sstrerror (errno, errbuf, sizeof (errbuf)));
183 return (-1);
184 }
186 dirlen = strlen (dir);
187 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
188 dir[--dirlen] = '\0';
190 if (dirlen <= 0)
191 return (-1);
193 status = chdir (dir);
194 if (status == 0)
195 {
196 free (dir);
197 return (0);
198 }
199 else if (errno != ENOENT)
200 {
201 char errbuf[1024];
202 ERROR ("change_basedir: chdir (%s): %s", dir,
203 sstrerror (errno, errbuf, sizeof (errbuf)));
204 free (dir);
205 return (-1);
206 }
208 status = mkdir (dir, S_IRWXU | S_IRWXG | S_IRWXO);
209 if (status != 0)
210 {
211 char errbuf[1024];
212 ERROR ("change_basedir: mkdir (%s): %s", dir,
213 sstrerror (errno, errbuf, sizeof (errbuf)));
214 free (dir);
215 return (-1);
216 }
218 status = chdir (dir);
219 if (status != 0)
220 {
221 char errbuf[1024];
222 ERROR ("change_basedir: chdir (%s): %s", dir,
223 sstrerror (errno, errbuf, sizeof (errbuf)));
224 free (dir);
225 return (-1);
226 }
228 free (dir);
229 return (0);
230 } /* static int change_basedir (char *dir) */
232 #if HAVE_LIBKSTAT
233 static void update_kstat (void)
234 {
235 if (kc == NULL)
236 {
237 if ((kc = kstat_open ()) == NULL)
238 ERROR ("Unable to open kstat control structure");
239 }
240 else
241 {
242 kid_t kid;
243 kid = kstat_chain_update (kc);
244 if (kid > 0)
245 {
246 INFO ("kstat chain has been updated");
247 plugin_init_all ();
248 }
249 else if (kid < 0)
250 ERROR ("kstat chain update failed");
251 /* else: everything works as expected */
252 }
254 return;
255 } /* static void update_kstat (void) */
256 #endif /* HAVE_LIBKSTAT */
258 /* TODO
259 * Remove all settings but `-f' and `-C'
260 */
261 static void exit_usage (int status)
262 {
263 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
265 "Available options:\n"
266 " General:\n"
267 " -C <file> Configuration file.\n"
268 " Default: "CONFIGFILE"\n"
269 " -t Test config and exit.\n"
270 " -T Test plugin read and exit.\n"
271 " -P <file> PID-file.\n"
272 " Default: "PIDFILE"\n"
273 #if COLLECT_DAEMON
274 " -f Don't fork to the background.\n"
275 #endif
276 " -h Display help (this message)\n"
277 "\nBuiltin defaults:\n"
278 " Config file "CONFIGFILE"\n"
279 " PID file "PIDFILE"\n"
280 " Plugin directory "PLUGINDIR"\n"
281 " Data directory "PKGLOCALSTATEDIR"\n"
282 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
283 "by Florian octo Forster <octo@collectd.org>\n"
284 "for contributions see `AUTHORS'\n");
285 exit (status);
286 } /* static void exit_usage (int status) */
288 static int do_init (void)
289 {
290 #if HAVE_LIBKSTAT
291 kc = NULL;
292 update_kstat ();
293 #endif
295 #if HAVE_LIBSTATGRAB
296 if (sg_init ())
297 {
298 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
299 return (-1);
300 }
302 if (sg_drop_privileges ())
303 {
304 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
305 return (-1);
306 }
307 #endif
309 plugin_init_all ();
311 return (0);
312 } /* int do_init () */
315 static int do_loop (void)
316 {
317 cdtime_t interval = cf_get_default_interval ();
318 cdtime_t wait_until;
320 wait_until = cdtime () + interval;
322 while (loop == 0)
323 {
324 struct timespec ts_wait = { 0, 0 };
325 cdtime_t now;
327 #if HAVE_LIBKSTAT
328 update_kstat ();
329 #endif
331 /* Issue all plugins */
332 plugin_read_all ();
334 now = cdtime ();
335 if (now >= wait_until)
336 {
337 WARNING ("Not sleeping because the next interval is "
338 "%.3f seconds in the past!",
339 CDTIME_T_TO_DOUBLE (now - wait_until));
340 wait_until = now + interval;
341 continue;
342 }
344 CDTIME_T_TO_TIMESPEC (wait_until - now, &ts_wait);
345 wait_until = wait_until + interval;
347 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) != 0))
348 {
349 if (errno != EINTR)
350 {
351 char errbuf[1024];
352 ERROR ("nanosleep failed: %s",
353 sstrerror (errno, errbuf,
354 sizeof (errbuf)));
355 return (-1);
356 }
357 }
358 } /* while (loop == 0) */
360 return (0);
361 } /* int do_loop */
363 static int do_shutdown (void)
364 {
365 plugin_shutdown_all ();
366 return (0);
367 } /* int do_shutdown */
369 #if COLLECT_DAEMON
370 static int pidfile_create (void)
371 {
372 FILE *fh;
373 const char *file = global_option_get ("PIDFile");
375 if ((fh = fopen (file, "w")) == NULL)
376 {
377 char errbuf[1024];
378 ERROR ("fopen (%s): %s", file,
379 sstrerror (errno, errbuf, sizeof (errbuf)));
380 return (1);
381 }
383 fprintf (fh, "%i\n", (int) getpid ());
384 fclose(fh);
386 return (0);
387 } /* static int pidfile_create (const char *file) */
389 static int pidfile_remove (void)
390 {
391 const char *file = global_option_get ("PIDFile");
393 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
394 return (unlink (file));
395 } /* static int pidfile_remove (const char *file) */
396 #endif /* COLLECT_DAEMON */
398 int main (int argc, char **argv)
399 {
400 struct sigaction sig_int_action;
401 struct sigaction sig_term_action;
402 struct sigaction sig_usr1_action;
403 struct sigaction sig_pipe_action;
404 char *configfile = CONFIGFILE;
405 int test_config = 0;
406 int test_readall = 0;
407 const char *basedir;
408 #if COLLECT_DAEMON
409 struct sigaction sig_chld_action;
410 pid_t pid;
411 int daemonize = 1;
412 #endif
413 int exit_status = 0;
415 /* read options */
416 while (1)
417 {
418 int c;
420 c = getopt (argc, argv, "htTC:"
421 #if COLLECT_DAEMON
422 "fP:"
423 #endif
424 );
426 if (c == -1)
427 break;
429 switch (c)
430 {
431 case 'C':
432 configfile = optarg;
433 break;
434 case 't':
435 test_config = 1;
436 break;
437 case 'T':
438 test_readall = 1;
439 global_option_set ("ReadThreads", "-1");
440 #if COLLECT_DAEMON
441 daemonize = 0;
442 #endif /* COLLECT_DAEMON */
443 break;
444 #if COLLECT_DAEMON
445 case 'P':
446 global_option_set ("PIDFile", optarg);
447 break;
448 case 'f':
449 daemonize = 0;
450 break;
451 #endif /* COLLECT_DAEMON */
452 case 'h':
453 exit_usage (0);
454 break;
455 default:
456 exit_usage (1);
457 } /* switch (c) */
458 } /* while (1) */
460 if (optind < argc)
461 exit_usage (1);
463 plugin_init_ctx ();
465 /*
466 * Read options from the config file, the environment and the command
467 * line (in that order, with later options overwriting previous ones in
468 * general).
469 * Also, this will automatically load modules.
470 */
471 if (cf_read (configfile))
472 {
473 fprintf (stderr, "Error: Reading the config file failed!\n"
474 "Read the syslog for details.\n");
475 return (1);
476 }
478 /*
479 * Change directory. We do this _after_ reading the config and loading
480 * modules to relative paths work as expected.
481 */
482 if ((basedir = global_option_get ("BaseDir")) == NULL)
483 {
484 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
485 return (1);
486 }
487 else if (change_basedir (basedir))
488 {
489 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
490 return (1);
491 }
493 /*
494 * Set global variables or, if that failes, exit. We cannot run with
495 * them being uninitialized. If nothing is configured, then defaults
496 * are being used. So this means that the user has actually done
497 * something wrong.
498 */
499 if (init_global_variables () != 0)
500 return (1);
502 if (test_config)
503 return (0);
505 #if COLLECT_DAEMON
506 /*
507 * fork off child
508 */
509 memset (&sig_chld_action, '\0', sizeof (sig_chld_action));
510 sig_chld_action.sa_handler = SIG_IGN;
511 sigaction (SIGCHLD, &sig_chld_action, NULL);
513 if (daemonize)
514 {
515 if ((pid = fork ()) == -1)
516 {
517 /* error */
518 char errbuf[1024];
519 fprintf (stderr, "fork: %s",
520 sstrerror (errno, errbuf,
521 sizeof (errbuf)));
522 return (1);
523 }
524 else if (pid != 0)
525 {
526 /* parent */
527 /* printf ("Running (PID %i)\n", pid); */
528 return (0);
529 }
531 /* Detach from session */
532 setsid ();
534 /* Write pidfile */
535 if (pidfile_create ())
536 exit (2);
538 /* close standard descriptors */
539 close (2);
540 close (1);
541 close (0);
543 if (open ("/dev/null", O_RDWR) != 0)
544 {
545 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
546 return (1);
547 }
548 if (dup (0) != 1)
549 {
550 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
551 return (1);
552 }
553 if (dup (0) != 2)
554 {
555 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
556 return (1);
557 }
558 } /* if (daemonize) */
559 #endif /* COLLECT_DAEMON */
561 memset (&sig_pipe_action, '\0', sizeof (sig_pipe_action));
562 sig_pipe_action.sa_handler = SIG_IGN;
563 sigaction (SIGPIPE, &sig_pipe_action, NULL);
565 /*
566 * install signal handlers
567 */
568 memset (&sig_int_action, '\0', sizeof (sig_int_action));
569 sig_int_action.sa_handler = sig_int_handler;
570 if (0 != sigaction (SIGINT, &sig_int_action, NULL)) {
571 char errbuf[1024];
572 ERROR ("Error: Failed to install a signal handler for signal INT: %s",
573 sstrerror (errno, errbuf, sizeof (errbuf)));
574 return (1);
575 }
577 memset (&sig_term_action, '\0', sizeof (sig_term_action));
578 sig_term_action.sa_handler = sig_term_handler;
579 if (0 != sigaction (SIGTERM, &sig_term_action, NULL)) {
580 char errbuf[1024];
581 ERROR ("Error: Failed to install a signal handler for signal TERM: %s",
582 sstrerror (errno, errbuf, sizeof (errbuf)));
583 return (1);
584 }
586 memset (&sig_usr1_action, '\0', sizeof (sig_usr1_action));
587 sig_usr1_action.sa_handler = sig_usr1_handler;
588 if (0 != sigaction (SIGUSR1, &sig_usr1_action, NULL)) {
589 char errbuf[1024];
590 ERROR ("Error: Failed to install a signal handler for signal USR1: %s",
591 sstrerror (errno, errbuf, sizeof (errbuf)));
592 return (1);
593 }
595 /*
596 * run the actual loops
597 */
598 do_init ();
600 if (test_readall)
601 {
602 if (plugin_read_all_once () != 0)
603 exit_status = 1;
604 }
605 else
606 {
607 INFO ("Initialization complete, entering read-loop.");
608 do_loop ();
609 }
611 /* close syslog */
612 INFO ("Exiting normally.");
614 do_shutdown ();
616 #if COLLECT_DAEMON
617 if (daemonize)
618 pidfile_remove ();
619 #endif /* COLLECT_DAEMON */
621 return (exit_status);
622 } /* int main */