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 " -t Test config and exit.\n"
231 " -P <file> PID-file.\n"
232 " Default: "PIDFILE"\n"
233 #if COLLECT_DAEMON
234 " -f Don't fork to the background.\n"
235 #endif
236 " -h Display help (this message)\n"
237 "\nBuiltin defaults:\n"
238 " Config-File "CONFIGFILE"\n"
239 " PID-File "PIDFILE"\n"
240 " Data-Directory "PKGLOCALSTATEDIR"\n"
241 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
242 "by Florian octo Forster <octo@verplant.org>\n"
243 "for contributions see `AUTHORS'\n");
244 exit (0);
245 } /* static void exit_usage (char *name) */
247 static int do_init (void)
248 {
249 #if HAVE_LIBKSTAT
250 kc = NULL;
251 update_kstat ();
252 #endif
254 #if HAVE_LIBSTATGRAB
255 if (sg_init ())
256 {
257 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
258 return (-1);
259 }
261 if (sg_drop_privileges ())
262 {
263 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
264 return (-1);
265 }
266 #endif
268 plugin_init_all ();
270 return (0);
271 } /* int do_init () */
274 static int do_loop (void)
275 {
276 struct timeval tv_now;
277 struct timeval tv_next;
278 struct timespec ts_wait;
280 while (loop == 0)
281 {
282 if (gettimeofday (&tv_next, NULL) < 0)
283 {
284 char errbuf[1024];
285 ERROR ("gettimeofday failed: %s",
286 sstrerror (errno, errbuf,
287 sizeof (errbuf)));
288 return (-1);
289 }
290 tv_next.tv_sec += interval_g;
292 #if HAVE_LIBKSTAT
293 update_kstat ();
294 #endif
296 /* Issue all plugins */
297 plugin_read_all ();
299 if (gettimeofday (&tv_now, NULL) < 0)
300 {
301 char errbuf[1024];
302 ERROR ("gettimeofday failed: %s",
303 sstrerror (errno, errbuf,
304 sizeof (errbuf)));
305 return (-1);
306 }
308 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
309 {
310 WARNING ("Not sleeping because "
311 "`timeval_sub_timespec' returned "
312 "non-zero!");
313 continue;
314 }
316 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
317 {
318 if (errno != EINTR)
319 {
320 char errbuf[1024];
321 ERROR ("nanosleep failed: %s",
322 sstrerror (errno, errbuf,
323 sizeof (errbuf)));
324 return (-1);
325 }
326 }
327 } /* while (loop == 0) */
329 DEBUG ("return (0);");
330 return (0);
331 } /* int do_loop */
333 static int do_shutdown (void)
334 {
335 plugin_shutdown_all ();
336 return (0);
337 } /* int do_shutdown */
339 #if COLLECT_DAEMON
340 static int pidfile_create (void)
341 {
342 FILE *fh;
343 const char *file = global_option_get ("PIDFile");
345 if ((fh = fopen (file, "w")) == NULL)
346 {
347 char errbuf[1024];
348 ERROR ("fopen (%s): %s", file,
349 sstrerror (errno, errbuf, sizeof (errbuf)));
350 return (1);
351 }
353 fprintf (fh, "%i\n", (int) getpid ());
354 fclose(fh);
356 return (0);
357 } /* static int pidfile_create (const char *file) */
359 static int pidfile_remove (void)
360 {
361 const char *file = global_option_get ("PIDFile");
363 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
364 return (unlink (file));
365 } /* static int pidfile_remove (const char *file) */
366 #endif /* COLLECT_DAEMON */
368 int main (int argc, char **argv)
369 {
370 struct sigaction sigIntAction;
371 struct sigaction sigTermAction;
372 char *configfile = CONFIGFILE;
373 int test_config = 0;
374 const char *basedir;
375 #if COLLECT_DAEMON
376 struct sigaction sigChldAction;
377 pid_t pid;
378 int daemonize = 1;
379 #endif
381 /* read options */
382 while (1)
383 {
384 int c;
386 c = getopt (argc, argv, "htC:"
387 #if COLLECT_DAEMON
388 "fP:"
389 #endif
390 );
392 if (c == -1)
393 break;
395 switch (c)
396 {
397 case 'C':
398 configfile = optarg;
399 break;
400 case 't':
401 test_config = 1;
402 break;
403 #if COLLECT_DAEMON
404 case 'P':
405 global_option_set ("PIDFile", optarg);
406 break;
407 case 'f':
408 daemonize = 0;
409 break;
410 #endif /* COLLECT_DAEMON */
411 case 'h':
412 default:
413 exit_usage ();
414 } /* switch (c) */
415 } /* while (1) */
417 /*
418 * Read options from the config file, the environment and the command
419 * line (in that order, with later options overwriting previous ones in
420 * general).
421 * Also, this will automatically load modules.
422 */
423 if (cf_read (configfile))
424 {
425 fprintf (stderr, "Error: Reading the config file failed!\n"
426 "Read the syslog for details.\n");
427 return (1);
428 }
430 /*
431 * Change directory. We do this _after_ reading the config and loading
432 * modules to relative paths work as expected.
433 */
434 if ((basedir = global_option_get ("BaseDir")) == NULL)
435 {
436 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
437 return (1);
438 }
439 else if (change_basedir (basedir))
440 {
441 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
442 return (1);
443 }
445 /*
446 * Set global variables or, if that failes, exit. We cannot run with
447 * them being uninitialized. If nothing is configured, then defaults
448 * are being used. So this means that the user has actually done
449 * something wrong.
450 */
451 if (init_global_variables () != 0)
452 return (1);
454 if (test_config)
455 return (0);
457 #if COLLECT_DAEMON
458 /*
459 * fork off child
460 */
461 memset (&sigChldAction, '\0', sizeof (sigChldAction));
462 sigChldAction.sa_handler = SIG_IGN;
463 sigaction (SIGCHLD, &sigChldAction, NULL);
465 if (daemonize)
466 {
467 if ((pid = fork ()) == -1)
468 {
469 /* error */
470 char errbuf[1024];
471 fprintf (stderr, "fork: %s",
472 sstrerror (errno, errbuf,
473 sizeof (errbuf)));
474 return (1);
475 }
476 else if (pid != 0)
477 {
478 /* parent */
479 /* printf ("Running (PID %i)\n", pid); */
480 return (0);
481 }
483 /* Detach from session */
484 setsid ();
486 /* Write pidfile */
487 if (pidfile_create ())
488 exit (2);
490 /* close standard descriptors */
491 close (2);
492 close (1);
493 close (0);
495 if (open ("/dev/null", O_RDWR) != 0)
496 {
497 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
498 return (1);
499 }
500 if (dup (0) != 1)
501 {
502 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
503 return (1);
504 }
505 if (dup (0) != 2)
506 {
507 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
508 return (1);
509 }
510 } /* if (daemonize) */
511 #endif /* COLLECT_DAEMON */
513 /*
514 * install signal handlers
515 */
516 memset (&sigIntAction, '\0', sizeof (sigIntAction));
517 sigIntAction.sa_handler = sigIntHandler;
518 sigaction (SIGINT, &sigIntAction, NULL);
520 memset (&sigTermAction, '\0', sizeof (sigTermAction));
521 sigTermAction.sa_handler = sigTermHandler;
522 sigaction (SIGTERM, &sigTermAction, NULL);
524 /*
525 * run the actual loops
526 */
527 do_init ();
528 do_loop ();
530 /* close syslog */
531 INFO ("Exiting normally");
533 do_shutdown ();
535 #if COLLECT_DAEMON
536 if (daemonize)
537 pidfile_remove ();
538 #endif /* COLLECT_DAEMON */
540 return (0);
541 } /* int main */