options, static, #if's and debugging
[collectd.git] / src / collectd.c
1 /**
2  * collectd - src/collectd.c
3  * Copyright (C) 2005  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; either version 2 of the License, or (at your
8  * option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License along
16  * with this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
18  *
19  * Authors:
20  *   Florian octo Forster <octo at verplant.org>
21  *   Alvaro Barcellos <alvaro.barcellos at gmail.com>
22  **/
23
24 #include "common.h"
25 #include "utils_debug.h"
26
27 #include "multicast.h"
28 #include "plugin.h"
29
30 #include "ping.h"
31
32 static int loop = 0;
33
34 #ifdef HAVE_LIBKSTAT
35 kstat_ctl_t *kc;
36 #endif /* HAVE_LIBKSTAT */
37
38 #if COLLECT_PING
39 char *pinghosts[MAX_PINGHOSTS];
40 int   num_pinghosts = 0;
41 #endif
42
43 /*
44  * exported variables
45  */
46 time_t curtime;
47
48 #ifdef HAVE_LIBRRD
49 int operating_mode;
50 #endif
51
52 static void sigIntHandler (int signal)
53 {
54         loop++;
55 }
56
57 static int change_basedir (char *dir)
58 {
59         int dirlen = strlen (dir);
60         
61         while ((dirlen > 0) && (dir[dirlen - 1] == '/'))
62                 dir[--dirlen] = '\0';
63
64         if (dirlen <= 0)
65                 return (-1);
66
67         if (chdir (dir) == -1)
68         {
69                 if (errno == ENOENT)
70                 {
71                         if (mkdir (dir, 0755) == -1)
72                         {
73                                 syslog (LOG_ERR, "mkdir: %s", strerror (errno));
74                                 return (-1);
75                         }
76                         else if (chdir (dir) == -1)
77                         {
78                                 syslog (LOG_ERR, "chdir: %s", strerror (errno));
79                                 return (-1);
80                         }
81                 }
82                 else
83                 {
84                         syslog (LOG_ERR, "chdir: %s", strerror (errno));
85                         return (-1);
86                 }
87         }
88
89         return (0);
90 } /* static int change_basedir (char *dir) */
91
92 #ifdef HAVE_LIBKSTAT
93 static void update_kstat (void)
94 {
95         if (kc == NULL)
96         {
97                 if ((kc = kstat_open ()) == NULL)
98                         syslog (LOG_ERR, "Unable to open kstat control structure");
99         }
100         else
101         {
102                 kid_t kid;
103                 kid = kstat_chain_update (kc);
104                 if (kid > 0)
105                 {
106                         syslog (LOG_INFO, "kstat chain has been updated");
107                         plugin_init_all ();
108                 }
109                 else if (kid < 0)
110                         syslog (LOG_ERR, "kstat chain update failed");
111                 /* else: everything works as expected */
112         }
113
114         return;
115 } /* static void update_kstat (void) */
116 #endif /* HAVE_LIBKSTAT */
117
118 static void exit_usage (char *name)
119 {
120         printf ("Usage: "PACKAGE" [OPTIONS]\n\n"
121                         
122                         "Available options:\n"
123                         "  General:\n"
124                         /*
125                         "    -C <file>       Configuration file.\n"
126                         "                    Default: "CONFIGFILE"\n"
127                         */
128 #if COLLECT_DAEMON
129                         "    -P <file>       PID file.\n"
130                         "                    Default: "PIDFILE"\n"
131 #endif
132                         "    -M <dir>        Module/Plugin directory.\n"
133                         "                    Default: "PLUGINDIR"\n"
134                         "    -D <dir>        Data storage directory.\n"
135                         "                    Default: "PKGLOCALSTATEDIR"\n"
136 #if COLLECT_DEBUG
137                         "    -L <file>       Log file.\n"
138                         "                    Default: "LOGFILE"\n"
139 #endif
140 #if COLLECT_DAEMON
141                         "    -f              Don't fork to the background.\n"
142 #endif
143 #if HAVE_LIBRRD
144                         "    -l              Start in local mode (no network).\n"
145                         "    -c              Start in client (sender) mode.\n"
146                         "    -s              Start in server (listener) mode.\n"
147 #endif /* HAVE_LIBRRD */
148 #if COLLECT_PING
149                         "  Ping:\n"
150                         "    -p <host>       Host to ping periodically, may be repeated to ping\n"
151                         "                    more than one host.\n"
152 #endif /* COLLECT_PING */
153                         "\n"PACKAGE" "VERSION", http://verplant.org/collectd/\n"
154                         "by Florian octo Forster <octo@verplant.org>\n"
155                         "for contributions see `AUTHORS'\n");
156         exit (0);
157 } /* static void exit_usage (char *name) */
158
159 static int start_client (void)
160 {
161         int sleepingtime;
162
163 #ifdef HAVE_LIBKSTAT
164         kc = NULL;
165         update_kstat ();
166 #endif
167
168 #ifdef HAVE_LIBSTATGRAB
169         if (sg_init ())
170         {
171                 syslog (LOG_ERR, "sg_init: %s", sg_str_error (sg_get_error ()));
172                 return (-1);
173         }
174
175         if (sg_drop_privileges ())
176         {
177                 syslog (LOG_ERR, "sg_drop_privileges: %s", sg_str_error (sg_get_error ()));
178                 return (-1);
179         }
180 #endif
181
182         plugin_init_all ();
183
184         while (loop == 0)
185         {
186                 curtime = time (NULL);
187 #ifdef HAVE_LIBKSTAT
188                 update_kstat ();
189 #endif
190                 plugin_read_all ();
191
192                 sleepingtime = 10;
193                 while (sleepingtime != 0)
194                 {
195                         if (loop != 0)
196                                 break;
197                         sleepingtime = sleep (sleepingtime);
198                 }
199         }
200
201         return (0);
202 } /* static int start_client (void) */
203
204 #ifdef HAVE_LIBRRD
205 static int start_server (void)
206 {
207         char *host;
208         char *type;
209         char *instance;
210         char *values;
211
212         while (loop == 0)
213         {
214                 if (multicast_receive (&host, &type, &instance, &values) == 0)
215                         plugin_write (host, type, instance, values);
216
217                 if (host     != NULL) free (host);     host     = NULL;
218                 if (type     != NULL) free (type);     type     = NULL;
219                 if (instance != NULL) free (instance); instance = NULL;
220                 if (values   != NULL) free (values);   values   = NULL;
221         }
222         
223         return (0);
224 } /* static int start_server (void) */
225 #endif /* HAVE_LIBRRD */
226
227 #if COLLECT_DAEMON
228 static int pidfile_create (char *file)
229 {
230         FILE *fh;
231
232         if (file == NULL)
233                 file = PIDFILE;
234
235         if ((fh = fopen (file, "w")) == NULL)
236         {
237                 syslog (LOG_ERR, "fopen (%s): %s", file, strerror (errno));
238                 return (1);
239         }
240
241         fprintf (fh, "%d\n", getpid());
242         fclose(fh);
243
244         return (0);
245 } /* static int pidfile_create (char *file) */
246 #endif /* COLLECT_DAEMON */
247
248 #if COLLECT_DAEMON
249 static int pidfile_remove (void)
250 {
251       return (unlink (PIDFILE));
252 } /* static int pidfile_remove (void) */
253 #endif /* COLLECT_DAEMON */
254
255 int main (int argc, char **argv)
256 {
257         struct sigaction sigIntAction, sigChldAction;
258         char *configfile = CONFIGFILE;
259         char *plugindir  = PLUGINDIR;
260         char *datadir    = PKGLOCALSTATEDIR;
261 #if COLLECT_DAEMON
262         char *pidfile    = PIDFILE;
263         pid_t pid;
264         int daemonize = 1;
265 #endif
266 #if COLLECT_DEBUG
267         char *logfile    = LOGFILE;
268 #endif
269
270 #ifdef HAVE_LIBRRD
271         operating_mode = MODE_LOCAL;
272 #endif
273
274         /* open syslog */
275         openlog (PACKAGE, LOG_CONS | LOG_PID, LOG_DAEMON);
276
277         /* read options */
278         while (1)
279         {
280                 int c;
281
282                 c = getopt (argc, argv, "C:M:D:h"
283 #if COLLECT_DAEMON
284                                 "fP:"
285 #endif
286 #if COLLECT_DEBUG
287                                 "L:"
288 #endif
289 #if HAVE_LIBRRD
290                                 "csl"
291 #endif /* HAVE_LIBRRD */
292 #if COLLECT_PING
293                                 "p:"
294 #endif /* COLLECT_PING */
295                 );
296
297                 if (c == -1)
298                         break;
299
300                 switch (c)
301                 {
302 #ifdef HAVE_LIBRRD
303                         case 'c':
304                                 operating_mode = MODE_CLIENT;
305                                 break;
306
307                         case 's':
308                                 operating_mode = MODE_SERVER;
309                                 break;
310
311                         case 'l':
312                                 operating_mode = MODE_LOCAL;
313                                 break;
314 #endif /* HAVE_LIBRRD */
315                         case 'C':
316                                 configfile = optarg;
317                                 break;
318 #if COLLECT_DAEMON
319                         case 'P':
320                                 pidfile = optarg;
321                                 break;
322                         case 'f':
323                                 daemonize = 0;
324                                 break;
325 #endif /* COLLECT_DAEMON */
326                         case 'M':
327                                 plugindir = optarg;
328                                 break;
329                         case 'D':
330                                 datadir = optarg;
331                                 break;
332 #if COLLECT_DEBUG
333                         case 'L':
334                                 logfile = optarg;
335                                 break;
336 #endif
337 #if COLLECT_PING
338                         case 'p':
339                                 if (num_pinghosts < MAX_PINGHOSTS)
340                                         pinghosts[num_pinghosts++] = optarg;
341                                 else
342                                         fprintf (stderr, "Maximum of %i ping hosts reached.\n", MAX_PINGHOSTS);
343                                 break;
344 #endif /* COLLECT_PING */
345                         case 'h':
346                         default:
347                                 exit_usage (argv[0]);
348                 } /* switch (c) */
349         } /* while (1) */
350
351         DBG_STARTFILE(logfile, "debug file opened.");
352
353         /*
354          * Load plugins and change to output directory
355          * Loading plugins is done first so relative paths work as expected..
356          */
357         if (plugin_load_all (plugindir) < 1)
358         {
359                 fprintf (stderr, "Error: No plugins found.\n");
360                 return (1);
361         }
362
363         if (change_basedir (datadir))
364         {
365                 fprintf (stderr, "Error: Unable to change to directory `%s'.\n", datadir);
366                 return (1);
367         }
368
369         /*
370          * install signal handlers
371          */
372         sigIntAction.sa_handler = sigIntHandler;
373         sigaction (SIGINT, &sigIntAction, NULL);
374
375         sigChldAction.sa_handler = SIG_IGN;
376         sigaction (SIGCHLD, &sigChldAction, NULL);
377
378         /*
379          * fork off child
380          */
381 #if COLLECT_DAEMON
382         if (daemonize)
383         {
384                 if ((pid = fork ()) == -1)
385                 {
386                         /* error */
387                         fprintf (stderr, "fork: %s", strerror (errno));
388                         return (1);
389                 }
390                 else if (pid != 0)
391                 {
392                         /* parent */
393                         /* printf ("Running (PID %i)\n", pid); */
394                         return (0);
395                 }
396
397                 /* Detach from session */
398                 setsid ();
399
400                 /* Write pidfile */
401                 if (pidfile_create (pidfile))
402                         exit (2);
403
404                 /* close standard descriptors */
405                 close (2);
406                 close (1);
407                 close (0);
408
409                 if (open ("/dev/null", O_RDWR) != 0)
410                 {
411                         syslog (LOG_ERR, "Error: Could not connect `STDIN' to `/dev/null'");
412                         return (1);
413                 }
414                 if (dup (0) != 1)
415                 {
416                         syslog (LOG_ERR, "Error: Could not connect `STDOUT' to `/dev/null'");
417                         return (1);
418                 }
419                 if (dup (0) != 2)
420                 {
421                         syslog (LOG_ERR, "Error: Could not connect `STDERR' to `/dev/null'");
422                         return (1);
423                 }
424         } /* if (daemonize) */
425 #endif /* COLLECT_DAEMON */
426
427         /*
428          * run the actual loops
429          */
430 #ifdef HAVE_LIBRRD
431         if (operating_mode == MODE_SERVER)
432                 start_server ();
433         else /* if (operating_mode == MODE_CLIENT || operating_mode == MODE_LOCAL) */
434 #endif
435                 start_client ();
436
437         DBG_STOPFILE("debug file closed.");
438
439         /* close syslog */
440         syslog (LOG_INFO, "Exiting normally");
441         closelog ();
442
443 #if COLLECT_DAEMON
444         if (daemonize)
445                 pidfile_remove();
446 #endif /* COLLECT_DAEMON */
447
448         return (0);
449 }