e873adc2d5f58890ae2590fd9993732b6efa3a3a
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 "network.h"
27 #include "plugin.h"
28 #include "configfile.h"
30 /*
31 * Global variables
32 */
33 char hostname_g[DATA_MAX_NAME_LEN];
34 int interval_g;
35 #if HAVE_LIBKSTAT
36 kstat_ctl_t *kc;
37 #endif /* HAVE_LIBKSTAT */
39 static int loop = 0;
41 static void sigIntHandler (int signal)
42 {
43 loop++;
44 }
46 static void sigTermHandler (int signal)
47 {
48 loop++;
49 }
51 static int init_global_variables (void)
52 {
53 const char *str;
55 str = global_option_get ("Hostname");
56 if (str != NULL)
57 {
58 strncpy (hostname_g, str, sizeof (hostname_g));
59 }
60 else
61 {
62 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
63 {
64 fprintf (stderr, "`gethostname' failed and no "
65 "hostname was configured.\n");
66 return (-1);
67 }
68 }
69 DEBUG ("hostname_g = %s;", hostname_g);
71 str = global_option_get ("Interval");
72 if (str == NULL)
73 str = COLLECTD_STEP;
74 interval_g = atoi (str);
75 if (interval_g <= 0)
76 {
77 fprintf (stderr, "Cannot set the interval to a correct value.\n"
78 "Please check your settings.\n");
79 return (-1);
80 }
81 DEBUG ("interval_g = %i;", interval_g);
83 return (0);
84 } /* int init_global_variables */
86 static int change_basedir (const char *orig_dir)
87 {
88 char *dir = strdup (orig_dir);
89 int dirlen;
90 int status;
92 if (dir == NULL)
93 {
94 ERROR ("strdup failed: %s", strerror (errno));
95 return (-1);
96 }
98 dirlen = strlen (dir);
99 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
100 dir[--dirlen] = '\0';
102 if (dirlen <= 0)
103 return (-1);
105 status = chdir (dir);
106 free (dir);
108 if (status != 0)
109 {
110 if (errno == ENOENT)
111 {
112 if (mkdir (orig_dir, 0755) == -1)
113 {
114 ERROR ("mkdir (%s): %s", orig_dir,
115 strerror (errno));
116 return (-1);
117 }
118 else if (chdir (orig_dir) == -1)
119 {
120 ERROR ("chdir (%s): %s", orig_dir,
121 strerror (errno));
122 return (-1);
123 }
124 }
125 else
126 {
127 ERROR ("chdir (%s): %s", orig_dir,
128 strerror (errno));
129 return (-1);
130 }
131 }
133 return (0);
134 } /* static int change_basedir (char *dir) */
136 #if HAVE_LIBKSTAT
137 static void update_kstat (void)
138 {
139 if (kc == NULL)
140 {
141 if ((kc = kstat_open ()) == NULL)
142 ERROR ("Unable to open kstat control structure");
143 }
144 else
145 {
146 kid_t kid;
147 kid = kstat_chain_update (kc);
148 if (kid > 0)
149 {
150 INFO ("kstat chain has been updated");
151 plugin_init_all ();
152 }
153 else if (kid < 0)
154 ERROR ("kstat chain update failed");
155 /* else: everything works as expected */
156 }
158 return;
159 } /* static void update_kstat (void) */
160 #endif /* HAVE_LIBKSTAT */
162 /* TODO
163 * Remove all settings but `-f' and `-C'
164 */
165 static void exit_usage (char *name)
166 {
167 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
169 "Available options:\n"
170 " General:\n"
171 " -C <file> Configuration file.\n"
172 " Default: "CONFIGFILE"\n"
173 " -P <file> PID-file.\n"
174 " Default: "PIDFILE"\n"
175 #if COLLECT_DAEMON
176 " -f Don't fork to the background.\n"
177 #endif
178 "\nBuiltin defaults:\n"
179 " Config-File "CONFIGFILE"\n"
180 " PID-File "PIDFILE"\n"
181 " Data-Directory "PKGLOCALSTATEDIR"\n"
182 #if COLLECT_DEBUG
183 " Log-File "LOGFILE"\n"
184 #endif
185 " Step "COLLECTD_STEP" seconds\n"
186 " Heartbeat "COLLECTD_HEARTBEAT" seconds\n"
187 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
188 "by Florian octo Forster <octo@verplant.org>\n"
189 "for contributions see `AUTHORS'\n");
190 exit (0);
191 } /* static void exit_usage (char *name) */
193 static int do_init (void)
194 {
195 #if HAVE_LIBKSTAT
196 kc = NULL;
197 update_kstat ();
198 #endif
200 #if HAVE_LIBSTATGRAB
201 if (sg_init ())
202 {
203 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
204 return (-1);
205 }
207 if (sg_drop_privileges ())
208 {
209 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
210 return (-1);
211 }
212 #endif
214 plugin_init_all ();
216 return (0);
217 } /* int do_init () */
220 static int do_loop (void)
221 {
222 struct timeval tv_now;
223 struct timeval tv_next;
224 struct timespec ts_wait;
226 while (loop == 0)
227 {
228 if (gettimeofday (&tv_next, NULL) < 0)
229 {
230 ERROR ("gettimeofday failed: %s", strerror (errno));
231 return (-1);
232 }
233 tv_next.tv_sec += interval_g;
235 #if HAVE_LIBKSTAT
236 update_kstat ();
237 #endif
239 /* Issue all plugins */
240 plugin_read_all (&loop);
242 if (gettimeofday (&tv_now, NULL) < 0)
243 {
244 ERROR ("gettimeofday failed: %s",
245 strerror (errno));
246 return (-1);
247 }
249 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
250 {
251 WARNING ("Not sleeping because "
252 "`timeval_sub_timespec' returned "
253 "non-zero!");
254 continue;
255 }
257 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
258 {
259 if (errno != EINTR)
260 {
261 ERROR ("nanosleep failed: %s", strerror (errno));
262 return (-1);
263 }
264 }
265 } /* while (loop == 0) */
267 DEBUG ("return (0);");
268 return (0);
269 } /* int do_loop */
271 static int do_shutdown (void)
272 {
273 plugin_shutdown_all ();
274 return (0);
275 } /* int do_shutdown */
277 #if COLLECT_DAEMON
278 static int pidfile_create (void)
279 {
280 FILE *fh;
281 const char *file = global_option_get ("PIDFile");
283 if ((fh = fopen (file, "w")) == NULL)
284 {
285 ERROR ("fopen (%s): %s", file, strerror (errno));
286 return (1);
287 }
289 fprintf (fh, "%i\n", (int) getpid ());
290 fclose(fh);
292 return (0);
293 } /* static int pidfile_create (const char *file) */
295 static int pidfile_remove (void)
296 {
297 const char *file = global_option_get ("PIDFile");
299 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
300 return (unlink (file));
301 } /* static int pidfile_remove (const char *file) */
302 #endif /* COLLECT_DAEMON */
304 int main (int argc, char **argv)
305 {
306 struct sigaction sigIntAction;
307 struct sigaction sigTermAction;
308 char *configfile = CONFIGFILE;
309 const char *basedir;
310 #if COLLECT_DAEMON
311 struct sigaction sigChldAction;
312 pid_t pid;
313 int daemonize = 1;
314 #endif
316 /* read options */
317 while (1)
318 {
319 int c;
321 c = getopt (argc, argv, "hC:"
322 #if COLLECT_DAEMON
323 "fP:"
324 #endif
325 );
327 if (c == -1)
328 break;
330 switch (c)
331 {
332 case 'C':
333 configfile = optarg;
334 break;
335 #if COLLECT_DAEMON
336 case 'P':
337 global_option_set ("PIDFile", optarg);
338 break;
339 case 'f':
340 daemonize = 0;
341 break;
342 #endif /* COLLECT_DAEMON */
343 case 'h':
344 default:
345 exit_usage (argv[0]);
346 } /* switch (c) */
347 } /* while (1) */
349 /*
350 * Read options from the config file, the environment and the command
351 * line (in that order, with later options overwriting previous ones in
352 * general).
353 * Also, this will automatically load modules.
354 */
355 if (cf_read (configfile))
356 {
357 fprintf (stderr, "Error: Reading the config file failed!\n"
358 "Read the syslog for details.\n");
359 return (1);
360 }
362 /*
363 * Change directory. We do this _after_ reading the config and loading
364 * modules to relative paths work as expected.
365 */
366 if ((basedir = global_option_get ("BaseDir")) == NULL)
367 {
368 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
369 return (1);
370 }
371 else if (change_basedir (basedir))
372 {
373 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
374 return (1);
375 }
377 /*
378 * Set global variables or, if that failes, exit. We cannot run with
379 * them being uninitialized. If nothing is configured, then defaults
380 * are being used. So this means that the user has actually done
381 * something wrong.
382 */
383 if (init_global_variables () != 0)
384 return (1);
386 #if COLLECT_DAEMON
387 /*
388 * fork off child
389 */
390 memset (&sigChldAction, '\0', sizeof (sigChldAction));
391 sigChldAction.sa_handler = SIG_IGN;
392 sigaction (SIGCHLD, &sigChldAction, NULL);
394 if (daemonize)
395 {
396 if ((pid = fork ()) == -1)
397 {
398 /* error */
399 fprintf (stderr, "fork: %s", strerror (errno));
400 return (1);
401 }
402 else if (pid != 0)
403 {
404 /* parent */
405 /* printf ("Running (PID %i)\n", pid); */
406 return (0);
407 }
409 /* Detach from session */
410 setsid ();
412 /* Write pidfile */
413 if (pidfile_create ())
414 exit (2);
416 /* close standard descriptors */
417 close (2);
418 close (1);
419 close (0);
421 if (open ("/dev/null", O_RDWR) != 0)
422 {
423 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
424 return (1);
425 }
426 if (dup (0) != 1)
427 {
428 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
429 return (1);
430 }
431 if (dup (0) != 2)
432 {
433 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
434 return (1);
435 }
436 } /* if (daemonize) */
437 #endif /* COLLECT_DAEMON */
439 /*
440 * install signal handlers
441 */
442 memset (&sigIntAction, '\0', sizeof (sigIntAction));
443 sigIntAction.sa_handler = sigIntHandler;
444 sigaction (SIGINT, &sigIntAction, NULL);
446 memset (&sigTermAction, '\0', sizeof (sigTermAction));
447 sigTermAction.sa_handler = sigTermHandler;
448 sigaction (SIGTERM, &sigTermAction, NULL);
450 /*
451 * run the actual loops
452 */
453 do_init ();
454 do_loop ();
456 /* close syslog */
457 INFO ("Exiting normally");
459 do_shutdown ();
461 #if COLLECT_DAEMON
462 if (daemonize)
463 pidfile_remove ();
464 #endif /* COLLECT_DAEMON */
466 return (0);
467 } /* int main */