61b5a1bdf7152661890743c6dc37665d40f60816
1 /**
2 * collectd - src/dns.c
3 * Copyright (C) 2006 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 **/
23 #include "collectd.h"
24 #include "common.h"
25 #include "plugin.h"
26 #include "configfile.h"
27 #include "utils_debug.h"
29 #if HAVE_PTHREAD_H
30 # include <pthread.h>
31 #endif
33 #if HAVE_SYS_POLL_H
34 # include <sys/poll.h>
35 #endif
37 #define MODULE_NAME "dns"
39 #if HAVE_LIBPCAP
40 # define NAMED_HAVE_CONFIG 1
41 #else
42 # define NAMED_HAVE_CONFIG 0
43 #endif
45 #if HAVE_LIBPCAP && HAVE_PTHREAD_H
46 # include "utils_dns.h"
47 # define NAMED_HAVE_READ 1
48 #else
49 # define NAMED_HAVE_READ 0
50 #endif
52 struct counter_list_s
53 {
54 unsigned int key;
55 unsigned int value;
56 struct counter_list_s *next;
57 };
58 typedef struct counter_list_s counter_list_t;
60 static char *traffic_file = "dns/dns_traffic.rrd";
61 static char *qtype_file = "dns/qtype-%s.rrd";
62 static char *opcode_file = "dns/opcode-%s.rrd";
63 static char *rcode_file = "dns/rcode-%s.rrd";
65 static char *traffic_ds_def[] =
66 {
67 /* Limit to 1GBit/s */
68 "DS:queries:COUNTER:"COLLECTD_HEARTBEAT":0:125000000",
69 "DS:responses:COUNTER:"COLLECTD_HEARTBEAT":0:125000000",
70 NULL
71 };
72 static int traffic_ds_num = 2;
74 static char *qtype_ds_def[] =
75 {
76 "DS:value:COUNTER:"COLLECTD_HEARTBEAT":0:65535",
77 NULL
78 };
79 static int qtype_ds_num = 1;
81 static char *opcode_ds_def[] =
82 {
83 "DS:value:COUNTER:"COLLECTD_HEARTBEAT":0:65535",
84 NULL
85 };
86 static int opcode_ds_num = 1;
88 static char *rcode_ds_def[] =
89 {
90 "DS:value:COUNTER:"COLLECTD_HEARTBEAT":0:65535",
91 NULL
92 };
93 static int rcode_ds_num = 1;
95 /* FIXME: Wouldn't other defines be better? -octo */
96 #if NAMED_HAVE_CONFIG
97 #if HAVE_LIBPCAP
98 static char *config_keys[] =
99 {
100 "Interface",
101 "IgnoreSource",
102 NULL
103 };
104 static int config_keys_num = 2;
105 #endif /* HAVE_LIBPCAP */
106 #endif /* NAMED_HAVE_CONFIG */
108 #if HAVE_LIBPCAP
109 #define PCAP_SNAPLEN 1460
110 static char *pcap_device = NULL;
112 static unsigned int tr_queries;
113 static unsigned int tr_responses;
114 static counter_list_t *qtype_list;
115 static counter_list_t *opcode_list;
116 static counter_list_t *rcode_list;
117 #endif
119 #if HAVE_PTHREAD_H
120 static pthread_t listen_thread;
121 static int listen_thread_init = 0;
122 /* The `traffic' mutex if for `tr_queries' and `tr_responses' */
123 static pthread_mutex_t traffic_mutex = PTHREAD_MUTEX_INITIALIZER;
124 static pthread_mutex_t qtype_mutex = PTHREAD_MUTEX_INITIALIZER;
125 static pthread_mutex_t opcode_mutex = PTHREAD_MUTEX_INITIALIZER;
126 static pthread_mutex_t rcode_mutex = PTHREAD_MUTEX_INITIALIZER;
127 #endif
129 static counter_list_t *counter_list_search (counter_list_t **list, unsigned int key)
130 {
131 counter_list_t *entry;
133 DBG ("counter_list_search (list = %p, key = %u)",
134 (void *) *list, key);
136 for (entry = *list; entry != NULL; entry = entry->next)
137 if (entry->key == key)
138 break;
140 DBG ("return (%p)", (void *) entry);
141 return (entry);
142 }
144 static counter_list_t *counter_list_create (counter_list_t **list,
145 unsigned int key, unsigned int value)
146 {
147 counter_list_t *entry;
149 DBG ("counter_list_create (list = %p, key = %u, value = %u)",
150 (void *) *list, key, value);
152 entry = (counter_list_t *) malloc (sizeof (counter_list_t));
153 if (entry == NULL)
154 return (NULL);
156 memset (entry, 0, sizeof (counter_list_t));
157 entry->key = key;
158 entry->value = value;
160 if (*list == NULL)
161 {
162 *list = entry;
163 }
164 else
165 {
166 counter_list_t *last;
168 last = *list;
169 while (last->next != NULL)
170 last = last->next;
172 last->next = entry;
173 }
175 DBG ("return (%p)", (void *) entry);
176 return (entry);
177 }
179 static void counter_list_add (counter_list_t **list,
180 unsigned int key, unsigned int increment)
181 {
182 counter_list_t *entry;
184 DBG ("counter_list_add (list = %p, key = %u, increment = %u)",
185 (void *) *list, key, increment);
187 entry = counter_list_search (list, key);
189 if (entry != NULL)
190 {
191 entry->value += increment;
192 }
193 else
194 {
195 counter_list_create (list, key, increment);
196 }
197 DBG ("return ()");
198 }
200 #if NAMED_HAVE_CONFIG
201 static int dns_config (char *key, char *value)
202 {
203 #if HAVE_LIBPCAP
204 if (strcasecmp (key, "Interface") == 0)
205 {
206 if (pcap_device != NULL)
207 free (pcap_device);
208 if ((pcap_device = strdup (value)) == NULL)
209 return (1);
210 }
211 else if (strcasecmp (key, "IgnoreSource") == 0)
212 {
213 if (value != NULL)
214 ignore_list_add_name (value);
215 }
216 else
217 {
218 return (-1);
219 }
221 return (0);
222 #endif /* HAVE_LIBPCAP */
223 }
224 #endif /* NAMED_HAVE_CONFIG */
226 static void dns_child_callback (const rfc1035_header_t *dns)
227 {
228 if (dns->qr == 0)
229 {
230 /* This is a query */
231 pthread_mutex_lock (&traffic_mutex);
232 tr_queries += dns->length;
233 pthread_mutex_unlock (&traffic_mutex);
235 pthread_mutex_lock (&qtype_mutex);
236 counter_list_add (&qtype_list, dns->qtype, 1);
237 pthread_mutex_unlock (&qtype_mutex);
238 }
239 else
240 {
241 /* This is a reply */
242 pthread_mutex_lock (&traffic_mutex);
243 tr_responses += dns->length;
244 pthread_mutex_unlock (&traffic_mutex);
246 pthread_mutex_lock (&rcode_mutex);
247 counter_list_add (&rcode_list, dns->rcode, 1);
248 pthread_mutex_unlock (&rcode_mutex);
249 }
251 /* FIXME: Are queries, replies or both interesting? */
252 pthread_mutex_lock (&opcode_mutex);
253 counter_list_add (&opcode_list, dns->opcode, 1);
254 pthread_mutex_unlock (&opcode_mutex);
255 }
257 static void *dns_child_loop (void *dummy)
258 {
259 pcap_t *pcap_obj;
260 char pcap_error[PCAP_ERRBUF_SIZE];
261 struct bpf_program fp;
263 struct pollfd poll_fds[1];
264 int status;
266 /* Don't block any signals */
267 {
268 sigset_t sigmask;
269 sigemptyset (&sigmask);
270 pthread_sigmask (SIG_SETMASK, &sigmask, NULL);
271 }
273 /* Passing `pcap_device == NULL' is okay and the same as passign "any" */
274 DBG ("Creating PCAP object..");
275 pcap_obj = pcap_open_live (pcap_device,
276 PCAP_SNAPLEN,
277 0 /* Not promiscuous */,
278 0 /* no read timeout */,
279 pcap_error);
280 if (pcap_obj == NULL)
281 {
282 syslog (LOG_ERR, "dns plugin: Opening interface `%s' "
283 "failed: %s",
284 (pcap_device != NULL) ? pcap_device : "any",
285 pcap_error);
286 return (NULL);
287 }
289 memset (&fp, 0, sizeof (fp));
290 if (pcap_compile (pcap_obj, &fp, "udp port 53", 1, 0) < 0)
291 {
292 DBG ("pcap_compile failed");
293 syslog (LOG_ERR, "dns plugin: pcap_compile failed");
294 return (NULL);
295 }
296 if (pcap_setfilter (pcap_obj, &fp) < 0)
297 {
298 DBG ("pcap_setfilter failed");
299 syslog (LOG_ERR, "dns plugin: pcap_setfilter failed");
300 return (NULL);
301 }
303 DBG ("PCAP object created.");
305 dnstop_set_pcap_obj (pcap_obj);
306 dnstop_set_callback (dns_child_callback);
308 /* Set up poll object */
309 poll_fds[0].fd = pcap_fileno (pcap_obj);
310 poll_fds[0].events = POLLIN | POLLPRI;
312 while (42)
313 {
314 DBG ("poll (...)");
315 status = poll (poll_fds, 1, -1 /* wait forever for a change */);
317 /* Signals are not caught, but this is very handy when
318 * attaching to the process with a debugger. -octo */
319 if ((status < 0) && (errno == EINTR))
320 {
321 errno = 0;
322 continue;
323 }
325 if (status < 0)
326 {
327 syslog (LOG_ERR, "dns plugin: poll(2) failed: %s",
328 strerror (errno));
329 break;
330 }
332 if (poll_fds[0].revents & (POLLERR | POLLHUP | POLLNVAL))
333 {
334 DBG ("pcap-device closed. Exiting.");
335 syslog (LOG_ERR, "dns plugin: pcap-device closed. Exiting.");
336 break;
337 }
338 else if (poll_fds[0].revents & (POLLIN | POLLPRI))
339 {
340 status = pcap_dispatch (pcap_obj,
341 10 /* Only handle 10 packets at a time */,
342 handle_pcap /* callback */,
343 NULL /* Whatever this means.. */);
344 if (status < 0)
345 {
346 DBG ("pcap_dispatch failed: %s", pcap_geterr (pcap_obj));
347 syslog (LOG_ERR, "dns plugin: pcap_dispatch failed: %s",
348 pcap_geterr (pcap_obj));
349 break;
350 }
351 }
352 } /* while (42) */
354 DBG ("child is exiting");
356 pcap_close (pcap_obj);
357 pthread_exit (NULL);
359 return (NULL);
360 } /* static void dns_child_loop (void) */
362 static void dns_init (void)
363 {
364 #if HAVE_LIBPCAP
365 #if HAVE_PTHREAD_H
366 /* clean up an old thread */
367 int status;
369 pthread_mutex_lock (&traffic_mutex);
370 tr_queries = 0;
371 tr_responses = 0;
372 pthread_mutex_unlock (&traffic_mutex);
374 if (listen_thread_init != 0)
375 return;
377 status = pthread_create (&listen_thread, NULL, dns_child_loop,
378 (void *) 0);
379 if (status != 0)
380 {
381 syslog (LOG_ERR, "dns plugin: pthread_create failed: %s",
382 strerror (status));
383 return;
384 }
386 listen_thread_init = 1;
387 #endif
388 #endif
389 }
391 static void traffic_write (char *host, char *inst, char *val)
392 {
393 rrd_update_file (host, traffic_file, val,
394 traffic_ds_def, traffic_ds_num);
395 }
397 static void qtype_write (char *host, char *inst, char *val)
398 {
399 char file[512];
400 int status;
402 status = snprintf (file, 512, qtype_file, inst);
403 if (status < 1)
404 return;
405 else if (status >= 512)
406 return;
408 rrd_update_file (host, file, val, qtype_ds_def, qtype_ds_num);
409 }
411 static void rcode_write (char *host, char *inst, char *val)
412 {
413 char file[512];
414 int status;
416 status = snprintf (file, 512, rcode_file, inst);
417 if (status < 1)
418 return;
419 else if (status >= 512)
420 return;
422 rrd_update_file (host, file, val, rcode_ds_def, rcode_ds_num);
423 }
425 static void opcode_write (char *host, char *inst, char *val)
426 {
427 char file[512];
428 int status;
430 status = snprintf (file, 512, opcode_file, inst);
431 if (status < 1)
432 return;
433 else if (status >= 512)
434 return;
436 rrd_update_file (host, file, val, opcode_ds_def, opcode_ds_num);
437 }
439 static void traffic_submit (unsigned int queries, unsigned int replies)
440 {
441 char buffer[64];
442 int status;
444 status = snprintf (buffer, 64, "N:%u:%u", queries, replies);
445 if ((status < 1) || (status >= 64))
446 return;
448 plugin_submit ("dns_traffic", "-", buffer);
449 }
451 static void qtype_submit (int qtype, unsigned int counter)
452 {
453 char inst[32];
454 char buffer[32];
455 int status;
457 strncpy (inst, qtype_str (qtype), 32);
458 inst[31] = '\0';
460 status = snprintf (buffer, 32, "N:%u", counter);
461 if ((status < 1) || (status >= 32))
462 return;
464 plugin_submit ("dns_qtype", inst, buffer);
465 }
467 static void rcode_submit (int rcode, unsigned int counter)
468 {
469 char inst[32];
470 char buffer[32];
471 int status;
473 strncpy (inst, rcode_str (rcode), 32);
474 inst[31] = '\0';
476 status = snprintf (buffer, 32, "N:%u", counter);
477 if ((status < 1) || (status >= 32))
478 return;
480 plugin_submit ("dns_rcode", inst, buffer);
481 }
483 static void opcode_submit (int opcode, unsigned int counter)
484 {
485 char inst[32];
486 char buffer[32];
487 int status;
489 strncpy (inst, opcode_str (opcode), 32);
490 inst[31] = '\0';
492 status = snprintf (buffer, 32, "N:%u", counter);
493 if ((status < 1) || (status >= 32))
494 return;
496 plugin_submit ("dns_opcode", inst, buffer);
497 }
499 #if NAMED_HAVE_READ
500 static void dns_read (void)
501 {
502 unsigned int keys[T_MAX];
503 unsigned int values[T_MAX];
504 int len;
505 int i;
507 counter_list_t *ptr;
509 pthread_mutex_lock (&traffic_mutex);
510 values[0] = tr_queries;
511 values[1] = tr_responses;
512 pthread_mutex_unlock (&traffic_mutex);
513 traffic_submit (values[0], values[1]);
515 pthread_mutex_lock (&qtype_mutex);
516 for (ptr = qtype_list, len = 0;
517 (ptr != NULL) && (len < T_MAX);
518 ptr = ptr->next, len++)
519 {
520 keys[len] = ptr->key;
521 values[len] = ptr->value;
522 }
523 pthread_mutex_unlock (&qtype_mutex);
525 for (i = 0; i < len; i++)
526 {
527 DBG ("qtype = %u; counter = %u;", keys[i], values[i]);
528 qtype_submit (keys[i], values[i]);
529 }
531 pthread_mutex_lock (&opcode_mutex);
532 for (ptr = opcode_list, len = 0;
533 (ptr != NULL) && (len < T_MAX);
534 ptr = ptr->next, len++)
535 {
536 keys[len] = ptr->key;
537 values[len] = ptr->value;
538 }
539 pthread_mutex_unlock (&opcode_mutex);
541 for (i = 0; i < len; i++)
542 {
543 DBG ("opcode = %u; counter = %u;", keys[i], values[i]);
544 opcode_submit (keys[i], values[i]);
545 }
547 pthread_mutex_lock (&rcode_mutex);
548 for (ptr = rcode_list, len = 0;
549 (ptr != NULL) && (len < T_MAX);
550 ptr = ptr->next, len++)
551 {
552 keys[len] = ptr->key;
553 values[len] = ptr->value;
554 }
555 pthread_mutex_unlock (&rcode_mutex);
557 for (i = 0; i < len; i++)
558 {
559 DBG ("rcode = %u; counter = %u;", keys[i], values[i]);
560 rcode_submit (keys[i], values[i]);
561 }
562 }
563 #else /* if !NAMED_HAVE_READ */
564 # define dns_read NULL
565 #endif
567 void module_register (void)
568 {
569 plugin_register (MODULE_NAME, dns_init, dns_read, NULL);
570 plugin_register ("dns_traffic", NULL, NULL, traffic_write);
571 plugin_register ("dns_qtype", NULL, NULL, qtype_write);
572 plugin_register ("dns_rcode", NULL, NULL, rcode_write);
573 plugin_register ("dns_opcode", NULL, NULL, opcode_write);
574 cf_register (MODULE_NAME, dns_config, config_keys, config_keys_num);
575 }
577 #undef MODULE_NAME