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 "plugin.h"
31 #include "configfile.h"
33 #if HAVE_STATGRAB_H
34 # include <statgrab.h>
35 #endif
37 /*
38 * Global variables
39 */
40 char hostname_g[DATA_MAX_NAME_LEN];
41 int interval_g;
42 #if HAVE_LIBKSTAT
43 kstat_ctl_t *kc;
44 #endif /* HAVE_LIBKSTAT */
46 static int loop = 0;
48 static void sigIntHandler (int signal)
49 {
50 loop++;
51 }
53 static void sigTermHandler (int signal)
54 {
55 loop++;
56 }
58 static int init_hostname (void)
59 {
60 const char *str;
62 struct addrinfo ai_hints;
63 struct addrinfo *ai_list;
64 struct addrinfo *ai_ptr;
65 int status;
67 str = global_option_get ("Hostname");
68 if (str != NULL)
69 {
70 strncpy (hostname_g, str, sizeof (hostname_g));
71 hostname_g[sizeof (hostname_g) - 1] = '\0';
72 return (0);
73 }
75 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
76 {
77 fprintf (stderr, "`gethostname' failed and no "
78 "hostname was configured.\n");
79 return (-1);
80 }
82 str = global_option_get ("FQDNLookup");
83 if ((strcasecmp ("false", str) == 0)
84 || (strcasecmp ("no", str) == 0)
85 || (strcasecmp ("off", str) == 0))
86 return (0);
88 memset (&ai_hints, '\0', sizeof (ai_hints));
89 ai_hints.ai_flags = AI_CANONNAME;
91 status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
92 if (status != 0)
93 {
94 ERROR ("Looking up \"%s\" failed. You have set the "
95 "\"FQDNLookup\" option, but I cannot resolve "
96 "my hostname to a fully qualified domain "
97 "name. Please fix you network "
98 "configuration.", hostname_g);
99 return (-1);
100 }
102 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
103 {
104 if (ai_ptr->ai_canonname == NULL)
105 continue;
107 strncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
108 hostname_g[sizeof (hostname_g) - 1] = '\0';
109 break;
110 }
112 freeaddrinfo (ai_list);
113 return (0);
114 } /* int init_hostname */
116 static int init_global_variables (void)
117 {
118 const char *str;
120 str = global_option_get ("Interval");
121 if (str == NULL)
122 str = "10";
123 interval_g = atoi (str);
124 if (interval_g <= 0)
125 {
126 fprintf (stderr, "Cannot set the interval to a correct value.\n"
127 "Please check your settings.\n");
128 return (-1);
129 }
130 DEBUG ("interval_g = %i;", interval_g);
132 if (init_hostname () != 0)
133 return (-1);
134 DEBUG ("hostname_g = %s;", hostname_g);
136 return (0);
137 } /* int init_global_variables */
139 static int change_basedir (const char *orig_dir)
140 {
141 char *dir = strdup (orig_dir);
142 int dirlen;
143 int status;
145 if (dir == NULL)
146 {
147 char errbuf[1024];
148 ERROR ("strdup failed: %s",
149 sstrerror (errno, errbuf, sizeof (errbuf)));
150 return (-1);
151 }
153 dirlen = strlen (dir);
154 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
155 dir[--dirlen] = '\0';
157 if (dirlen <= 0)
158 return (-1);
160 status = chdir (dir);
161 free (dir);
163 if (status != 0)
164 {
165 if (errno == ENOENT)
166 {
167 if (mkdir (orig_dir, 0755) == -1)
168 {
169 char errbuf[1024];
170 ERROR ("change_basedir: mkdir (%s): %s", orig_dir,
171 sstrerror (errno, errbuf,
172 sizeof (errbuf)));
173 return (-1);
174 }
175 else if (chdir (orig_dir) == -1)
176 {
177 char errbuf[1024];
178 ERROR ("chdir (%s): %s", orig_dir,
179 sstrerror (errno, errbuf,
180 sizeof (errbuf)));
181 return (-1);
182 }
183 }
184 else
185 {
186 char errbuf[1024];
187 ERROR ("chdir (%s): %s", orig_dir,
188 sstrerror (errno, errbuf,
189 sizeof (errbuf)));
190 return (-1);
191 }
192 }
194 return (0);
195 } /* static int change_basedir (char *dir) */
197 #if HAVE_LIBKSTAT
198 static void update_kstat (void)
199 {
200 if (kc == NULL)
201 {
202 if ((kc = kstat_open ()) == NULL)
203 ERROR ("Unable to open kstat control structure");
204 }
205 else
206 {
207 kid_t kid;
208 kid = kstat_chain_update (kc);
209 if (kid > 0)
210 {
211 INFO ("kstat chain has been updated");
212 plugin_init_all ();
213 }
214 else if (kid < 0)
215 ERROR ("kstat chain update failed");
216 /* else: everything works as expected */
217 }
219 return;
220 } /* static void update_kstat (void) */
221 #endif /* HAVE_LIBKSTAT */
223 /* TODO
224 * Remove all settings but `-f' and `-C'
225 */
226 static void exit_usage (void)
227 {
228 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
230 "Available options:\n"
231 " General:\n"
232 " -C <file> Configuration file.\n"
233 " Default: "CONFIGFILE"\n"
234 " -P <file> PID-file.\n"
235 " Default: "PIDFILE"\n"
236 #if COLLECT_DAEMON
237 " -f Don't fork to the background.\n"
238 #endif
239 "\nBuiltin defaults:\n"
240 " Config-File "CONFIGFILE"\n"
241 " PID-File "PIDFILE"\n"
242 " Data-Directory "PKGLOCALSTATEDIR"\n"
243 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
244 "by Florian octo Forster <octo@verplant.org>\n"
245 "for contributions see `AUTHORS'\n");
246 exit (0);
247 } /* static void exit_usage (char *name) */
249 static int do_init (void)
250 {
251 #if HAVE_LIBKSTAT
252 kc = NULL;
253 update_kstat ();
254 #endif
256 #if HAVE_LIBSTATGRAB
257 if (sg_init ())
258 {
259 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
260 return (-1);
261 }
263 if (sg_drop_privileges ())
264 {
265 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
266 return (-1);
267 }
268 #endif
270 plugin_init_all ();
272 return (0);
273 } /* int do_init () */
276 static int do_loop (void)
277 {
278 struct timeval tv_now;
279 struct timeval tv_next;
280 struct timespec ts_wait;
282 while (loop == 0)
283 {
284 if (gettimeofday (&tv_next, NULL) < 0)
285 {
286 char errbuf[1024];
287 ERROR ("gettimeofday failed: %s",
288 sstrerror (errno, errbuf,
289 sizeof (errbuf)));
290 return (-1);
291 }
292 tv_next.tv_sec += interval_g;
294 #if HAVE_LIBKSTAT
295 update_kstat ();
296 #endif
298 /* Issue all plugins */
299 plugin_read_all ();
301 if (gettimeofday (&tv_now, NULL) < 0)
302 {
303 char errbuf[1024];
304 ERROR ("gettimeofday failed: %s",
305 sstrerror (errno, errbuf,
306 sizeof (errbuf)));
307 return (-1);
308 }
310 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
311 {
312 WARNING ("Not sleeping because "
313 "`timeval_sub_timespec' returned "
314 "non-zero!");
315 continue;
316 }
318 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
319 {
320 if (errno != EINTR)
321 {
322 char errbuf[1024];
323 ERROR ("nanosleep failed: %s",
324 sstrerror (errno, errbuf,
325 sizeof (errbuf)));
326 return (-1);
327 }
328 }
329 } /* while (loop == 0) */
331 DEBUG ("return (0);");
332 return (0);
333 } /* int do_loop */
335 static int do_shutdown (void)
336 {
337 plugin_shutdown_all ();
338 return (0);
339 } /* int do_shutdown */
341 #if COLLECT_DAEMON
342 static int pidfile_create (void)
343 {
344 FILE *fh;
345 const char *file = global_option_get ("PIDFile");
347 if ((fh = fopen (file, "w")) == NULL)
348 {
349 char errbuf[1024];
350 ERROR ("fopen (%s): %s", file,
351 sstrerror (errno, errbuf, sizeof (errbuf)));
352 return (1);
353 }
355 fprintf (fh, "%i\n", (int) getpid ());
356 fclose(fh);
358 return (0);
359 } /* static int pidfile_create (const char *file) */
361 static int pidfile_remove (void)
362 {
363 const char *file = global_option_get ("PIDFile");
365 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
366 return (unlink (file));
367 } /* static int pidfile_remove (const char *file) */
368 #endif /* COLLECT_DAEMON */
370 int main (int argc, char **argv)
371 {
372 struct sigaction sigIntAction;
373 struct sigaction sigTermAction;
374 char *configfile = CONFIGFILE;
375 int test_config = 0;
376 const char *basedir;
377 #if COLLECT_DAEMON
378 struct sigaction sigChldAction;
379 pid_t pid;
380 int daemonize = 1;
381 #endif
383 /* read options */
384 while (1)
385 {
386 int c;
388 c = getopt (argc, argv, "htC:"
389 #if COLLECT_DAEMON
390 "fP:"
391 #endif
392 );
394 if (c == -1)
395 break;
397 switch (c)
398 {
399 case 'C':
400 configfile = optarg;
401 break;
402 case 't':
403 test_config = 1;
404 break;
405 #if COLLECT_DAEMON
406 case 'P':
407 global_option_set ("PIDFile", optarg);
408 break;
409 case 'f':
410 daemonize = 0;
411 break;
412 #endif /* COLLECT_DAEMON */
413 case 'h':
414 default:
415 exit_usage ();
416 } /* switch (c) */
417 } /* while (1) */
419 /*
420 * Read options from the config file, the environment and the command
421 * line (in that order, with later options overwriting previous ones in
422 * general).
423 * Also, this will automatically load modules.
424 */
425 if (cf_read (configfile))
426 {
427 fprintf (stderr, "Error: Reading the config file failed!\n"
428 "Read the syslog for details.\n");
429 return (1);
430 }
432 /*
433 * Change directory. We do this _after_ reading the config and loading
434 * modules to relative paths work as expected.
435 */
436 if ((basedir = global_option_get ("BaseDir")) == NULL)
437 {
438 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
439 return (1);
440 }
441 else if (change_basedir (basedir))
442 {
443 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
444 return (1);
445 }
447 /*
448 * Set global variables or, if that failes, exit. We cannot run with
449 * them being uninitialized. If nothing is configured, then defaults
450 * are being used. So this means that the user has actually done
451 * something wrong.
452 */
453 if (init_global_variables () != 0)
454 return (1);
456 if (test_config)
457 return (0);
459 #if COLLECT_DAEMON
460 /*
461 * fork off child
462 */
463 memset (&sigChldAction, '\0', sizeof (sigChldAction));
464 sigChldAction.sa_handler = SIG_IGN;
465 sigaction (SIGCHLD, &sigChldAction, NULL);
467 if (daemonize)
468 {
469 if ((pid = fork ()) == -1)
470 {
471 /* error */
472 char errbuf[1024];
473 fprintf (stderr, "fork: %s",
474 sstrerror (errno, errbuf,
475 sizeof (errbuf)));
476 return (1);
477 }
478 else if (pid != 0)
479 {
480 /* parent */
481 /* printf ("Running (PID %i)\n", pid); */
482 return (0);
483 }
485 /* Detach from session */
486 setsid ();
488 /* Write pidfile */
489 if (pidfile_create ())
490 exit (2);
492 /* close standard descriptors */
493 close (2);
494 close (1);
495 close (0);
497 if (open ("/dev/null", O_RDWR) != 0)
498 {
499 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
500 return (1);
501 }
502 if (dup (0) != 1)
503 {
504 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
505 return (1);
506 }
507 if (dup (0) != 2)
508 {
509 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
510 return (1);
511 }
512 } /* if (daemonize) */
513 #endif /* COLLECT_DAEMON */
515 /*
516 * install signal handlers
517 */
518 memset (&sigIntAction, '\0', sizeof (sigIntAction));
519 sigIntAction.sa_handler = sigIntHandler;
520 sigaction (SIGINT, &sigIntAction, NULL);
522 memset (&sigTermAction, '\0', sizeof (sigTermAction));
523 sigTermAction.sa_handler = sigTermHandler;
524 sigaction (SIGTERM, &sigTermAction, NULL);
526 /*
527 * run the actual loops
528 */
529 do_init ();
530 do_loop ();
532 /* close syslog */
533 INFO ("Exiting normally");
535 do_shutdown ();
537 #if COLLECT_DAEMON
538 if (daemonize)
539 pidfile_remove ();
540 #endif /* COLLECT_DAEMON */
542 return (0);
543 } /* int main */