49998f96101b9c7d94e48d76aa92c63c7b80eff9
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 "plugin.h"
27 #include "configfile.h"
28 #include "types_list.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 = "10";
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 char errbuf[1024];
95 ERROR ("strdup failed: %s",
96 sstrerror (errno, errbuf, sizeof (errbuf)));
97 return (-1);
98 }
100 dirlen = strlen (dir);
101 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
102 dir[--dirlen] = '\0';
104 if (dirlen <= 0)
105 return (-1);
107 status = chdir (dir);
108 free (dir);
110 if (status != 0)
111 {
112 if (errno == ENOENT)
113 {
114 if (mkdir (orig_dir, 0755) == -1)
115 {
116 char errbuf[1024];
117 ERROR ("mkdir (%s): %s", orig_dir,
118 sstrerror (errno, errbuf,
119 sizeof (errbuf)));
120 return (-1);
121 }
122 else if (chdir (orig_dir) == -1)
123 {
124 char errbuf[1024];
125 ERROR ("chdir (%s): %s", orig_dir,
126 sstrerror (errno, errbuf,
127 sizeof (errbuf)));
128 return (-1);
129 }
130 }
131 else
132 {
133 char errbuf[1024];
134 ERROR ("chdir (%s): %s", orig_dir,
135 sstrerror (errno, errbuf,
136 sizeof (errbuf)));
137 return (-1);
138 }
139 }
141 return (0);
142 } /* static int change_basedir (char *dir) */
144 #if HAVE_LIBKSTAT
145 static void update_kstat (void)
146 {
147 if (kc == NULL)
148 {
149 if ((kc = kstat_open ()) == NULL)
150 ERROR ("Unable to open kstat control structure");
151 }
152 else
153 {
154 kid_t kid;
155 kid = kstat_chain_update (kc);
156 if (kid > 0)
157 {
158 INFO ("kstat chain has been updated");
159 plugin_init_all ();
160 }
161 else if (kid < 0)
162 ERROR ("kstat chain update failed");
163 /* else: everything works as expected */
164 }
166 return;
167 } /* static void update_kstat (void) */
168 #endif /* HAVE_LIBKSTAT */
170 /* TODO
171 * Remove all settings but `-f' and `-C'
172 */
173 static void exit_usage (char *name)
174 {
175 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
177 "Available options:\n"
178 " General:\n"
179 " -C <file> Configuration file.\n"
180 " Default: "CONFIGFILE"\n"
181 " -P <file> PID-file.\n"
182 " Default: "PIDFILE"\n"
183 #if COLLECT_DAEMON
184 " -f Don't fork to the background.\n"
185 #endif
186 "\nBuiltin defaults:\n"
187 " Config-File "CONFIGFILE"\n"
188 " PID-File "PIDFILE"\n"
189 " Data-Directory "PKGLOCALSTATEDIR"\n"
190 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
191 "by Florian octo Forster <octo@verplant.org>\n"
192 "for contributions see `AUTHORS'\n");
193 exit (0);
194 } /* static void exit_usage (char *name) */
196 static int do_init (void)
197 {
198 #if HAVE_LIBKSTAT
199 kc = NULL;
200 update_kstat ();
201 #endif
203 #if HAVE_LIBSTATGRAB
204 if (sg_init ())
205 {
206 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
207 return (-1);
208 }
210 if (sg_drop_privileges ())
211 {
212 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
213 return (-1);
214 }
215 #endif
217 read_types_list ();
218 plugin_init_all ();
220 return (0);
221 } /* int do_init () */
224 static int do_loop (void)
225 {
226 struct timeval tv_now;
227 struct timeval tv_next;
228 struct timespec ts_wait;
230 while (loop == 0)
231 {
232 if (gettimeofday (&tv_next, NULL) < 0)
233 {
234 char errbuf[1024];
235 ERROR ("gettimeofday failed: %s",
236 sstrerror (errno, errbuf,
237 sizeof (errbuf)));
238 return (-1);
239 }
240 tv_next.tv_sec += interval_g;
242 #if HAVE_LIBKSTAT
243 update_kstat ();
244 #endif
246 /* Issue all plugins */
247 plugin_read_all (&loop);
249 if (gettimeofday (&tv_now, NULL) < 0)
250 {
251 char errbuf[1024];
252 ERROR ("gettimeofday failed: %s",
253 sstrerror (errno, errbuf,
254 sizeof (errbuf)));
255 return (-1);
256 }
258 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
259 {
260 WARNING ("Not sleeping because "
261 "`timeval_sub_timespec' returned "
262 "non-zero!");
263 continue;
264 }
266 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
267 {
268 if (errno != EINTR)
269 {
270 char errbuf[1024];
271 ERROR ("nanosleep failed: %s",
272 sstrerror (errno, errbuf,
273 sizeof (errbuf)));
274 return (-1);
275 }
276 }
277 } /* while (loop == 0) */
279 DEBUG ("return (0);");
280 return (0);
281 } /* int do_loop */
283 static int do_shutdown (void)
284 {
285 plugin_shutdown_all ();
286 return (0);
287 } /* int do_shutdown */
289 #if COLLECT_DAEMON
290 static int pidfile_create (void)
291 {
292 FILE *fh;
293 const char *file = global_option_get ("PIDFile");
295 if ((fh = fopen (file, "w")) == NULL)
296 {
297 char errbuf[1024];
298 ERROR ("fopen (%s): %s", file,
299 sstrerror (errno, errbuf, sizeof (errbuf)));
300 return (1);
301 }
303 fprintf (fh, "%i\n", (int) getpid ());
304 fclose(fh);
306 return (0);
307 } /* static int pidfile_create (const char *file) */
309 static int pidfile_remove (void)
310 {
311 const char *file = global_option_get ("PIDFile");
313 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
314 return (unlink (file));
315 } /* static int pidfile_remove (const char *file) */
316 #endif /* COLLECT_DAEMON */
318 int main (int argc, char **argv)
319 {
320 struct sigaction sigIntAction;
321 struct sigaction sigTermAction;
322 char *configfile = CONFIGFILE;
323 const char *basedir;
324 #if COLLECT_DAEMON
325 struct sigaction sigChldAction;
326 pid_t pid;
327 int daemonize = 1;
328 #endif
330 /* read options */
331 while (1)
332 {
333 int c;
335 c = getopt (argc, argv, "hC:"
336 #if COLLECT_DAEMON
337 "fP:"
338 #endif
339 );
341 if (c == -1)
342 break;
344 switch (c)
345 {
346 case 'C':
347 configfile = optarg;
348 break;
349 #if COLLECT_DAEMON
350 case 'P':
351 global_option_set ("PIDFile", optarg);
352 break;
353 case 'f':
354 daemonize = 0;
355 break;
356 #endif /* COLLECT_DAEMON */
357 case 'h':
358 default:
359 exit_usage (argv[0]);
360 } /* switch (c) */
361 } /* while (1) */
363 /*
364 * Read options from the config file, the environment and the command
365 * line (in that order, with later options overwriting previous ones in
366 * general).
367 * Also, this will automatically load modules.
368 */
369 if (cf_read (configfile))
370 {
371 fprintf (stderr, "Error: Reading the config file failed!\n"
372 "Read the syslog for details.\n");
373 return (1);
374 }
376 /*
377 * Change directory. We do this _after_ reading the config and loading
378 * modules to relative paths work as expected.
379 */
380 if ((basedir = global_option_get ("BaseDir")) == NULL)
381 {
382 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
383 return (1);
384 }
385 else if (change_basedir (basedir))
386 {
387 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
388 return (1);
389 }
391 /*
392 * Set global variables or, if that failes, exit. We cannot run with
393 * them being uninitialized. If nothing is configured, then defaults
394 * are being used. So this means that the user has actually done
395 * something wrong.
396 */
397 if (init_global_variables () != 0)
398 return (1);
400 #if COLLECT_DAEMON
401 /*
402 * fork off child
403 */
404 memset (&sigChldAction, '\0', sizeof (sigChldAction));
405 sigChldAction.sa_handler = SIG_IGN;
406 sigaction (SIGCHLD, &sigChldAction, NULL);
408 if (daemonize)
409 {
410 if ((pid = fork ()) == -1)
411 {
412 /* error */
413 char errbuf[1024];
414 fprintf (stderr, "fork: %s",
415 sstrerror (errno, errbuf,
416 sizeof (errbuf)));
417 return (1);
418 }
419 else if (pid != 0)
420 {
421 /* parent */
422 /* printf ("Running (PID %i)\n", pid); */
423 return (0);
424 }
426 /* Detach from session */
427 setsid ();
429 /* Write pidfile */
430 if (pidfile_create ())
431 exit (2);
433 /* close standard descriptors */
434 close (2);
435 close (1);
436 close (0);
438 if (open ("/dev/null", O_RDWR) != 0)
439 {
440 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
441 return (1);
442 }
443 if (dup (0) != 1)
444 {
445 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
446 return (1);
447 }
448 if (dup (0) != 2)
449 {
450 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
451 return (1);
452 }
453 } /* if (daemonize) */
454 #endif /* COLLECT_DAEMON */
456 /*
457 * install signal handlers
458 */
459 memset (&sigIntAction, '\0', sizeof (sigIntAction));
460 sigIntAction.sa_handler = sigIntHandler;
461 sigaction (SIGINT, &sigIntAction, NULL);
463 memset (&sigTermAction, '\0', sizeof (sigTermAction));
464 sigTermAction.sa_handler = sigTermHandler;
465 sigaction (SIGTERM, &sigTermAction, NULL);
467 /*
468 * run the actual loops
469 */
470 do_init ();
471 do_loop ();
473 /* close syslog */
474 INFO ("Exiting normally");
476 do_shutdown ();
478 #if COLLECT_DAEMON
479 if (daemonize)
480 pidfile_remove ();
481 #endif /* COLLECT_DAEMON */
483 return (0);
484 } /* int main */