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"
29 /*
30 * Global variables
31 */
32 char hostname_g[DATA_MAX_NAME_LEN];
33 int interval_g;
34 #if HAVE_LIBKSTAT
35 kstat_ctl_t *kc;
36 #endif /* HAVE_LIBKSTAT */
38 static int loop = 0;
40 static void sigIntHandler (int signal)
41 {
42 loop++;
43 }
45 static void sigTermHandler (int signal)
46 {
47 loop++;
48 }
50 static int init_global_variables (void)
51 {
52 const char *str;
54 str = global_option_get ("Hostname");
55 if (str != NULL)
56 {
57 strncpy (hostname_g, str, sizeof (hostname_g));
58 }
59 else
60 {
61 if (gethostname (hostname_g, sizeof (hostname_g)) != 0)
62 {
63 fprintf (stderr, "`gethostname' failed and no "
64 "hostname was configured.\n");
65 return (-1);
66 }
67 }
68 DEBUG ("hostname_g = %s;", hostname_g);
70 str = global_option_get ("Interval");
71 if (str == NULL)
72 str = "10";
73 interval_g = atoi (str);
74 if (interval_g <= 0)
75 {
76 fprintf (stderr, "Cannot set the interval to a correct value.\n"
77 "Please check your settings.\n");
78 return (-1);
79 }
80 DEBUG ("interval_g = %i;", interval_g);
82 return (0);
83 } /* int init_global_variables */
85 static int change_basedir (const char *orig_dir)
86 {
87 char *dir = strdup (orig_dir);
88 int dirlen;
89 int status;
91 if (dir == NULL)
92 {
93 char errbuf[1024];
94 ERROR ("strdup failed: %s",
95 sstrerror (errno, errbuf, sizeof (errbuf)));
96 return (-1);
97 }
99 dirlen = strlen (dir);
100 while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
101 dir[--dirlen] = '\0';
103 if (dirlen <= 0)
104 return (-1);
106 status = chdir (dir);
107 free (dir);
109 if (status != 0)
110 {
111 if (errno == ENOENT)
112 {
113 if (mkdir (orig_dir, 0755) == -1)
114 {
115 char errbuf[1024];
116 ERROR ("mkdir (%s): %s", orig_dir,
117 sstrerror (errno, errbuf,
118 sizeof (errbuf)));
119 return (-1);
120 }
121 else if (chdir (orig_dir) == -1)
122 {
123 char errbuf[1024];
124 ERROR ("chdir (%s): %s", orig_dir,
125 sstrerror (errno, errbuf,
126 sizeof (errbuf)));
127 return (-1);
128 }
129 }
130 else
131 {
132 char errbuf[1024];
133 ERROR ("chdir (%s): %s", orig_dir,
134 sstrerror (errno, errbuf,
135 sizeof (errbuf)));
136 return (-1);
137 }
138 }
140 return (0);
141 } /* static int change_basedir (char *dir) */
143 #if HAVE_LIBKSTAT
144 static void update_kstat (void)
145 {
146 if (kc == NULL)
147 {
148 if ((kc = kstat_open ()) == NULL)
149 ERROR ("Unable to open kstat control structure");
150 }
151 else
152 {
153 kid_t kid;
154 kid = kstat_chain_update (kc);
155 if (kid > 0)
156 {
157 INFO ("kstat chain has been updated");
158 plugin_init_all ();
159 }
160 else if (kid < 0)
161 ERROR ("kstat chain update failed");
162 /* else: everything works as expected */
163 }
165 return;
166 } /* static void update_kstat (void) */
167 #endif /* HAVE_LIBKSTAT */
169 /* TODO
170 * Remove all settings but `-f' and `-C'
171 */
172 static void exit_usage (char *name)
173 {
174 printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
176 "Available options:\n"
177 " General:\n"
178 " -C <file> Configuration file.\n"
179 " Default: "CONFIGFILE"\n"
180 " -P <file> PID-file.\n"
181 " Default: "PIDFILE"\n"
182 #if COLLECT_DAEMON
183 " -f Don't fork to the background.\n"
184 #endif
185 "\nBuiltin defaults:\n"
186 " Config-File "CONFIGFILE"\n"
187 " PID-File "PIDFILE"\n"
188 " Data-Directory "PKGLOCALSTATEDIR"\n"
189 "\n"PACKAGE" "VERSION", http://collectd.org/\n"
190 "by Florian octo Forster <octo@verplant.org>\n"
191 "for contributions see `AUTHORS'\n");
192 exit (0);
193 } /* static void exit_usage (char *name) */
195 static int do_init (void)
196 {
197 #if HAVE_LIBKSTAT
198 kc = NULL;
199 update_kstat ();
200 #endif
202 #if HAVE_LIBSTATGRAB
203 if (sg_init ())
204 {
205 ERROR ("sg_init: %s", sg_str_error (sg_get_error ()));
206 return (-1);
207 }
209 if (sg_drop_privileges ())
210 {
211 ERROR ("sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
212 return (-1);
213 }
214 #endif
216 plugin_init_all ();
218 return (0);
219 } /* int do_init () */
222 static int do_loop (void)
223 {
224 struct timeval tv_now;
225 struct timeval tv_next;
226 struct timespec ts_wait;
228 while (loop == 0)
229 {
230 if (gettimeofday (&tv_next, NULL) < 0)
231 {
232 char errbuf[1024];
233 ERROR ("gettimeofday failed: %s",
234 sstrerror (errno, errbuf,
235 sizeof (errbuf)));
236 return (-1);
237 }
238 tv_next.tv_sec += interval_g;
240 #if HAVE_LIBKSTAT
241 update_kstat ();
242 #endif
244 /* Issue all plugins */
245 plugin_read_all (&loop);
247 if (gettimeofday (&tv_now, NULL) < 0)
248 {
249 char errbuf[1024];
250 ERROR ("gettimeofday failed: %s",
251 sstrerror (errno, errbuf,
252 sizeof (errbuf)));
253 return (-1);
254 }
256 if (timeval_sub_timespec (&tv_next, &tv_now, &ts_wait) != 0)
257 {
258 WARNING ("Not sleeping because "
259 "`timeval_sub_timespec' returned "
260 "non-zero!");
261 continue;
262 }
264 while ((loop == 0) && (nanosleep (&ts_wait, &ts_wait) == -1))
265 {
266 if (errno != EINTR)
267 {
268 char errbuf[1024];
269 ERROR ("nanosleep failed: %s",
270 sstrerror (errno, errbuf,
271 sizeof (errbuf)));
272 return (-1);
273 }
274 }
275 } /* while (loop == 0) */
277 DEBUG ("return (0);");
278 return (0);
279 } /* int do_loop */
281 static int do_shutdown (void)
282 {
283 plugin_shutdown_all ();
284 return (0);
285 } /* int do_shutdown */
287 #if COLLECT_DAEMON
288 static int pidfile_create (void)
289 {
290 FILE *fh;
291 const char *file = global_option_get ("PIDFile");
293 if ((fh = fopen (file, "w")) == NULL)
294 {
295 char errbuf[1024];
296 ERROR ("fopen (%s): %s", file,
297 sstrerror (errno, errbuf, sizeof (errbuf)));
298 return (1);
299 }
301 fprintf (fh, "%i\n", (int) getpid ());
302 fclose(fh);
304 return (0);
305 } /* static int pidfile_create (const char *file) */
307 static int pidfile_remove (void)
308 {
309 const char *file = global_option_get ("PIDFile");
311 DEBUG ("unlink (%s)", (file != NULL) ? file : "<null>");
312 return (unlink (file));
313 } /* static int pidfile_remove (const char *file) */
314 #endif /* COLLECT_DAEMON */
316 int main (int argc, char **argv)
317 {
318 struct sigaction sigIntAction;
319 struct sigaction sigTermAction;
320 char *configfile = CONFIGFILE;
321 const char *basedir;
322 #if COLLECT_DAEMON
323 struct sigaction sigChldAction;
324 pid_t pid;
325 int daemonize = 1;
326 #endif
328 /* read options */
329 while (1)
330 {
331 int c;
333 c = getopt (argc, argv, "hC:"
334 #if COLLECT_DAEMON
335 "fP:"
336 #endif
337 );
339 if (c == -1)
340 break;
342 switch (c)
343 {
344 case 'C':
345 configfile = optarg;
346 break;
347 #if COLLECT_DAEMON
348 case 'P':
349 global_option_set ("PIDFile", optarg);
350 break;
351 case 'f':
352 daemonize = 0;
353 break;
354 #endif /* COLLECT_DAEMON */
355 case 'h':
356 default:
357 exit_usage (argv[0]);
358 } /* switch (c) */
359 } /* while (1) */
361 /*
362 * Read options from the config file, the environment and the command
363 * line (in that order, with later options overwriting previous ones in
364 * general).
365 * Also, this will automatically load modules.
366 */
367 if (cf_read (configfile))
368 {
369 fprintf (stderr, "Error: Reading the config file failed!\n"
370 "Read the syslog for details.\n");
371 return (1);
372 }
374 /*
375 * Change directory. We do this _after_ reading the config and loading
376 * modules to relative paths work as expected.
377 */
378 if ((basedir = global_option_get ("BaseDir")) == NULL)
379 {
380 fprintf (stderr, "Don't have a basedir to use. This should not happen. Ever.");
381 return (1);
382 }
383 else if (change_basedir (basedir))
384 {
385 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", basedir);
386 return (1);
387 }
389 /*
390 * Set global variables or, if that failes, exit. We cannot run with
391 * them being uninitialized. If nothing is configured, then defaults
392 * are being used. So this means that the user has actually done
393 * something wrong.
394 */
395 if (init_global_variables () != 0)
396 return (1);
398 #if COLLECT_DAEMON
399 /*
400 * fork off child
401 */
402 memset (&sigChldAction, '\0', sizeof (sigChldAction));
403 sigChldAction.sa_handler = SIG_IGN;
404 sigaction (SIGCHLD, &sigChldAction, NULL);
406 if (daemonize)
407 {
408 if ((pid = fork ()) == -1)
409 {
410 /* error */
411 char errbuf[1024];
412 fprintf (stderr, "fork: %s",
413 sstrerror (errno, errbuf,
414 sizeof (errbuf)));
415 return (1);
416 }
417 else if (pid != 0)
418 {
419 /* parent */
420 /* printf ("Running (PID %i)\n", pid); */
421 return (0);
422 }
424 /* Detach from session */
425 setsid ();
427 /* Write pidfile */
428 if (pidfile_create ())
429 exit (2);
431 /* close standard descriptors */
432 close (2);
433 close (1);
434 close (0);
436 if (open ("/dev/null", O_RDWR) != 0)
437 {
438 ERROR ("Error: Could not connect `STDIN' to `/dev/null'");
439 return (1);
440 }
441 if (dup (0) != 1)
442 {
443 ERROR ("Error: Could not connect `STDOUT' to `/dev/null'");
444 return (1);
445 }
446 if (dup (0) != 2)
447 {
448 ERROR ("Error: Could not connect `STDERR' to `/dev/null'");
449 return (1);
450 }
451 } /* if (daemonize) */
452 #endif /* COLLECT_DAEMON */
454 /*
455 * install signal handlers
456 */
457 memset (&sigIntAction, '\0', sizeof (sigIntAction));
458 sigIntAction.sa_handler = sigIntHandler;
459 sigaction (SIGINT, &sigIntAction, NULL);
461 memset (&sigTermAction, '\0', sizeof (sigTermAction));
462 sigTermAction.sa_handler = sigTermHandler;
463 sigaction (SIGTERM, &sigTermAction, NULL);
465 /*
466 * run the actual loops
467 */
468 do_init ();
469 do_loop ();
471 /* close syslog */
472 INFO ("Exiting normally");
474 do_shutdown ();
476 #if COLLECT_DAEMON
477 if (daemonize)
478 pidfile_remove ();
479 #endif /* COLLECT_DAEMON */
481 return (0);
482 } /* int main */