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 /*
34 * Global variables
35 */
36 char hostname_g[DATA_MAX_NAME_LEN];
37 int interval_g;
38 #if HAVE_LIBKSTAT
39 kstat_ctl_t *kc;
40 #endif /* HAVE_LIBKSTAT */
42 static int loop = 0;
44 static void sigIntHandler (int signal)
45 {
46 loop++;
47 }
49 static void sigTermHandler (int signal)
50 {
51 loop++;
52 }
54 static int init_hostname (void)
55 {
56 const char *str;
58 struct addrinfo ai_hints;
59 struct addrinfo *ai_list;
60 struct addrinfo *ai_ptr;
61 int status;
63 str = global_option_get ("Hostname");
64 if (str != NULL)
65 {
66 strncpy (hostname_g, str, sizeof (hostname_g));
67 hostname_g[sizeof (hostname_g) - 1] = '\0';
68 return (0);
69 }
71 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
72 {
73 fprintf (stderr, "`gethostname' failed and no "
74 "hostname was configured.\n");
75 return (-1);
76 }
78 str = global_option_get ("FQDNLookup");
79 if ((strcasecmp ("false", str) == 0)
80 || (strcasecmp ("no", str) == 0)
81 || (strcasecmp ("off", str) == 0))
82 return (0);
84 memset (&ai_hints, '\0', sizeof (ai_hints));
85 ai_hints.ai_flags = AI_CANONNAME;
87 status = getaddrinfo (hostname_g, NULL, &ai_hints, &ai_list);
88 if (status != 0)
89 {
90 ERROR ("Looking up \"%s\" failed. You have set the "
91 "\"FQDNLookup\" option, but I cannot resolve "
92 "my hostname to a fully qualified domain "
93 "name. Please fix you network "
94 "configuration.", hostname_g);
95 return (-1);
96 }
98 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
99 {
100 if (ai_ptr->ai_canonname == NULL)
101 continue;
103 strncpy (hostname_g, ai_ptr->ai_canonname, sizeof (hostname_g));
104 hostname_g[sizeof (hostname_g) - 1] = '\0';
105 break;
106 }
108 freeaddrinfo (ai_list);
109 return (0);
110 } /* int init_hostname */
112 static int init_global_variables (void)
113 {
114 const char *str;
116 str = global_option_get ("Interval");
117 if (str == NULL)
118 str = "10";
119 interval_g = atoi (str);
120 if (interval_g <= 0)
121 {
122 fprintf (stderr, "Cannot set the interval to a correct value.\n"
123 "Please check your settings.\n");
124 return (-1);
125 }
126 DEBUG ("interval_g = %i;", interval_g);
128 if (init_hostname () != 0)
129 return (-1);
130 DEBUG ("hostname_g = %s;", hostname_g);
132 return (0);
133 } /* int init_global_variables */
135 static int change_basedir (const char *orig_dir)
136 {
137 char *dir = strdup (orig_dir);
138 int dirlen;
139 int status;
141 if (dir == NULL)
142 {
143 char errbuf[1024];
144 ERROR ("strdup failed: %s",
145 sstrerror (errno, errbuf, sizeof (errbuf)));
146 return (-1);
147 }
149 dirlen = strlen (dir);
150 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
151 dir[--dirlen] = '\0';
153 if (dirlen <= 0)
154 return (-1);
156 status = chdir (dir);
157 free (dir);
159 if (status != 0)
160 {
161 if (errno == ENOENT)
162 {
163 if (mkdir (orig_dir, 0755) == -1)
164 {
165 char errbuf[1024];
166 ERROR ("change_basedir: mkdir (%s): %s", orig_dir,
167 sstrerror (errno, errbuf,
168 sizeof (errbuf)));
169 return (-1);
170 }
171 else if (chdir (orig_dir) == -1)
172 {
173 char errbuf[1024];
174 ERROR ("chdir (%s): %s", orig_dir,
175 sstrerror (errno, errbuf,
176 sizeof (errbuf)));
177 return (-1);
178 }
179 }
180 else
181 {
182 char errbuf[1024];
183 ERROR ("chdir (%s): %s", orig_dir,
184 sstrerror (errno, errbuf,
185 sizeof (errbuf)));
186 return (-1);
187 }
188 }
190 return (0);
191 } /* static int change_basedir (char *dir) */
193 #if HAVE_LIBKSTAT
194 static void update_kstat (void)
195 {
196 if (kc == NULL)
197 {
198 if ((kc = kstat_open ()) == NULL)
199 ERROR ("Unable to open kstat control structure");
200 }
201 else
202 {
203 kid_t kid;
204 kid = kstat_chain_update (kc);
205 if (kid > 0)
206 {
207 INFO ("kstat chain has been updated");
208 plugin_init_all ();
209 }
210 else if (kid < 0)
211 ERROR ("kstat chain update failed");
212 /* else: everything works as expected */
213 }
215 return;
216 } /* static void update_kstat (void) */
217 #endif /* HAVE_LIBKSTAT */
219 /* TODO
220 * Remove all settings but `-f' and `-C'
221 */
222 static void exit_usage (void)
223 {
224 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
226 "Available options:\n"
227 " General:\n"
228 " -C <file> Configuration file.\n"
229 " Default: "CONFIGFILE"\n"
230 " -P <file> PID-file.\n"
231 " Default: "PIDFILE"\n"
232 #if COLLECT_DAEMON
233 " -f Don't fork to the background.\n"
234 #endif
235 "\nBuiltin defaults:\n"
236 " Config-File "CONFIGFILE"\n"
237 " PID-File "PIDFILE"\n"
238 " Data-Directory "PKGLOCALSTATEDIR"\n"
239 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
240 "by Florian octo Forster <octo@verplant.org>\n"
241 "for contributions see `AUTHORS'\n");
242 exit (0);
243 } /* static void exit_usage (char *name) */
245 static int do_init (void)
246 {
247 #if HAVE_LIBKSTAT
248 kc = NULL;
249 update_kstat ();
250 #endif
252 #if HAVE_LIBSTATGRAB
253 if (sg_init ())
254 {
255 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
256 return (-1);
257 }
259 if (sg_drop_privileges ())
260 {
261 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
262 return (-1);
263 }
264 #endif
266 plugin_init_all ();
268 return (0);
269 } /* int do_init () */
272 static int do_loop (void)
273 {
274 struct timeval tv_now;
275 struct timeval tv_next;
276 struct timespec ts_wait;
278 while (loop == 0)
279 {
280 if (gettimeofday (&tv_next, NULL) < 0)
281 {
282 char errbuf[1024];
283 ERROR ("gettimeofday failed: %s",
284 sstrerror (errno, errbuf,
285 sizeof (errbuf)));
286 return (-1);
287 }
288 tv_next.tv_sec += interval_g;
290 #if HAVE_LIBKSTAT
291 update_kstat ();
292 #endif
294 /* Issue all plugins */
295 plugin_read_all ();
297 if (gettimeofday (&tv_now, NULL) < 0)
298 {
299 char errbuf[1024];
300 ERROR ("gettimeofday failed: %s",
301 sstrerror (errno, errbuf,
302 sizeof (errbuf)));
303 return (-1);
304 }
306 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
307 {
308 WARNING ("Not sleeping because "
309 "`timeval_sub_timespec' returned "
310 "non-zero!");
311 continue;
312 }
314 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
315 {
316 if (errno != EINTR)
317 {
318 char errbuf[1024];
319 ERROR ("nanosleep failed: %s",
320 sstrerror (errno, errbuf,
321 sizeof (errbuf)));
322 return (-1);
323 }
324 }
325 } /* while (loop == 0) */
327 DEBUG ("return (0);");
328 return (0);
329 } /* int do_loop */
331 static int do_shutdown (void)
332 {
333 plugin_shutdown_all ();
334 return (0);
335 } /* int do_shutdown */
337 #if COLLECT_DAEMON
338 static int pidfile_create (void)
339 {
340 FILE *fh;
341 const char *file = global_option_get ("PIDFile");
343 if ((fh = fopen (file, "w")) == NULL)
344 {
345 char errbuf[1024];
346 ERROR ("fopen (%s): %s", file,
347 sstrerror (errno, errbuf, sizeof (errbuf)));
348 return (1);
349 }
351 fprintf (fh, "%i\n", (int) getpid ());
352 fclose(fh);
354 return (0);
355 } /* static int pidfile_create (const char *file) */
357 static int pidfile_remove (void)
358 {
359 const char *file = global_option_get ("PIDFile");
361 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
362 return (unlink (file));
363 } /* static int pidfile_remove (const char *file) */
364 #endif /* COLLECT_DAEMON */
366 int main (int argc, char **argv)
367 {
368 struct sigaction sigIntAction;
369 struct sigaction sigTermAction;
370 char *configfile = CONFIGFILE;
371 int test_config = 0;
372 const char *basedir;
373 #if COLLECT_DAEMON
374 struct sigaction sigChldAction;
375 pid_t pid;
376 int daemonize = 1;
377 #endif
379 /* read options */
380 while (1)
381 {
382 int c;
384 c = getopt (argc, argv, "htC:"
385 #if COLLECT_DAEMON
386 "fP:"
387 #endif
388 );
390 if (c == -1)
391 break;
393 switch (c)
394 {
395 case 'C':
396 configfile = optarg;
397 break;
398 case 't':
399 test_config = 1;
400 break;
401 #if COLLECT_DAEMON
402 case 'P':
403 global_option_set ("PIDFile", optarg);
404 break;
405 case 'f':
406 daemonize = 0;
407 break;
408 #endif /* COLLECT_DAEMON */
409 case 'h':
410 default:
411 exit_usage ();
412 } /* switch (c) */
413 } /* while (1) */
415 /*
416 * Read options from the config file, the environment and the command
417 * line (in that order, with later options overwriting previous ones in
418 * general).
419 * Also, this will automatically load modules.
420 */
421 if (cf_read (configfile))
422 {
423 fprintf (stderr, "Error: Reading the config file failed!\n"
424 "Read the syslog for details.\n");
425 return (1);
426 }
428 /*
429 * Change directory. We do this _after_ reading the config and loading
430 * modules to relative paths work as expected.
431 */
432 if ((basedir = global_option_get ("BaseDir")) == NULL)
433 {
434 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
435 return (1);
436 }
437 else if (change_basedir (basedir))
438 {
439 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
440 return (1);
441 }
443 /*
444 * Set global variables or, if that failes, exit. We cannot run with
445 * them being uninitialized. If nothing is configured, then defaults
446 * are being used. So this means that the user has actually done
447 * something wrong.
448 */
449 if (init_global_variables () != 0)
450 return (1);
452 if (test_config)
453 return (0);
455 #if COLLECT_DAEMON
456 /*
457 * fork off child
458 */
459 memset (&sigChldAction, '\0', sizeof (sigChldAction));
460 sigChldAction.sa_handler = SIG_IGN;
461 sigaction (SIGCHLD, &sigChldAction, NULL);
463 if (daemonize)
464 {
465 if ((pid = fork ()) == -1)
466 {
467 /* error */
468 char errbuf[1024];
469 fprintf (stderr, "fork: %s",
470 sstrerror (errno, errbuf,
471 sizeof (errbuf)));
472 return (1);
473 }
474 else if (pid != 0)
475 {
476 /* parent */
477 /* printf ("Running (PID %i)\n", pid); */
478 return (0);
479 }
481 /* Detach from session */
482 setsid ();
484 /* Write pidfile */
485 if (pidfile_create ())
486 exit (2);
488 /* close standard descriptors */
489 close (2);
490 close (1);
491 close (0);
493 if (open ("/dev/null", O_RDWR) != 0)
494 {
495 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
496 return (1);
497 }
498 if (dup (0) != 1)
499 {
500 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
501 return (1);
502 }
503 if (dup (0) != 2)
504 {
505 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
506 return (1);
507 }
508 } /* if (daemonize) */
509 #endif /* COLLECT_DAEMON */
511 /*
512 * install signal handlers
513 */
514 memset (&sigIntAction, '\0', sizeof (sigIntAction));
515 sigIntAction.sa_handler = sigIntHandler;
516 sigaction (SIGINT, &sigIntAction, NULL);
518 memset (&sigTermAction, '\0', sizeof (sigTermAction));
519 sigTermAction.sa_handler = sigTermHandler;
520 sigaction (SIGTERM, &sigTermAction, NULL);
522 /*
523 * run the actual loops
524 */
525 do_init ();
526 do_loop ();
528 /* close syslog */
529 INFO ("Exiting normally");
531 do_shutdown ();
533 #if COLLECT_DAEMON
534 if (daemonize)
535 pidfile_remove ();
536 #endif /* COLLECT_DAEMON */
538 return (0);
539 } /* int main */