da45a389ba1e8bae67d26886fbf9255d5f91d321
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 catch these signals */
267 /* FIXME: Really? */
268 signal (SIGINT, SIG_DFL);
269 signal (SIGTERM, SIG_DFL);
271 /* Passing `pcap_device == NULL' is okay and the same as passign "any" */
272 DBG ("Creating PCAP object..");
273 pcap_obj = pcap_open_live (pcap_device,
274 PCAP_SNAPLEN,
275 0 /* Not promiscuous */,
276 0 /* no read timeout */,
277 pcap_error);
278 if (pcap_obj == NULL)
279 {
280 syslog (LOG_ERR, "dns plugin: Opening interface `%s' "
281 "failed: %s",
282 (pcap_device != NULL) ? pcap_device : "any",
283 pcap_error);
284 return (NULL);
285 }
287 memset (&fp, 0, sizeof (fp));
288 if (pcap_compile (pcap_obj, &fp, "udp port 53", 1, 0) < 0)
289 {
290 DBG ("pcap_compile failed");
291 syslog (LOG_ERR, "dns plugin: pcap_compile failed");
292 return (NULL);
293 }
294 if (pcap_setfilter (pcap_obj, &fp) < 0)
295 {
296 DBG ("pcap_setfilter failed");
297 syslog (LOG_ERR, "dns plugin: pcap_setfilter failed");
298 return (NULL);
299 }
301 DBG ("PCAP object created.");
303 dnstop_set_pcap_obj (pcap_obj);
304 dnstop_set_callback (dns_child_callback);
306 /* Set up poll object */
307 poll_fds[0].fd = pcap_fileno (pcap_obj);
308 poll_fds[0].events = POLLIN | POLLPRI;
310 while (42)
311 {
312 DBG ("poll (...)");
313 status = poll (poll_fds, 1, -1 /* wait forever for a change */);
315 /* Signals are not caught, but this is very handy when
316 * attaching to the process with a debugger. -octo */
317 if ((status < 0) && (errno == EINTR))
318 {
319 errno = 0;
320 continue;
321 }
323 if (status < 0)
324 {
325 syslog (LOG_ERR, "dns plugin: poll(2) failed: %s",
326 strerror (errno));
327 break;
328 }
330 if (poll_fds[0].revents & (POLLERR | POLLHUP | POLLNVAL))
331 {
332 DBG ("pcap-device closed. Exiting.");
333 syslog (LOG_ERR, "dns plugin: pcap-device closed. Exiting.");
334 break;
335 }
336 else if (poll_fds[0].revents & (POLLIN | POLLPRI))
337 {
338 status = pcap_dispatch (pcap_obj,
339 10 /* Only handle 10 packets at a time */,
340 handle_pcap /* callback */,
341 NULL /* Whatever this means.. */);
342 if (status < 0)
343 {
344 DBG ("pcap_dispatch failed: %s", pcap_geterr (pcap_obj));
345 syslog (LOG_ERR, "dns plugin: pcap_dispatch failed: %s",
346 pcap_geterr (pcap_obj));
347 break;
348 }
349 }
350 } /* while (42) */
352 DBG ("child is exiting");
354 pcap_close (pcap_obj);
355 pthread_exit (NULL);
357 return (NULL);
358 } /* static void dns_child_loop (void) */
360 static void dns_init (void)
361 {
362 #if HAVE_LIBPCAP
363 #if HAVE_PTHREAD_H
364 /* clean up an old thread */
365 int status;
367 pthread_mutex_lock (&traffic_mutex);
368 tr_queries = 0;
369 tr_responses = 0;
370 pthread_mutex_unlock (&traffic_mutex);
372 if (listen_thread_init != 0)
373 return;
375 status = pthread_create (&listen_thread, NULL, dns_child_loop,
376 (void *) 0);
377 if (status != 0)
378 {
379 syslog (LOG_ERR, "dns plugin: pthread_create failed: %s",
380 strerror (status));
381 return;
382 }
384 listen_thread_init = 1;
385 #endif
386 #endif
387 }
389 static void traffic_write (char *host, char *inst, char *val)
390 {
391 rrd_update_file (host, traffic_file, val,
392 traffic_ds_def, traffic_ds_num);
393 }
395 static void qtype_write (char *host, char *inst, char *val)
396 {
397 char file[512];
398 int status;
400 status = snprintf (file, 512, qtype_file, inst);
401 if (status < 1)
402 return;
403 else if (status >= 512)
404 return;
406 rrd_update_file (host, file, val, qtype_ds_def, qtype_ds_num);
407 }
409 static void rcode_write (char *host, char *inst, char *val)
410 {
411 char file[512];
412 int status;
414 status = snprintf (file, 512, rcode_file, inst);
415 if (status < 1)
416 return;
417 else if (status >= 512)
418 return;
420 rrd_update_file (host, file, val, rcode_ds_def, rcode_ds_num);
421 }
423 static void opcode_write (char *host, char *inst, char *val)
424 {
425 char file[512];
426 int status;
428 status = snprintf (file, 512, opcode_file, inst);
429 if (status < 1)
430 return;
431 else if (status >= 512)
432 return;
434 rrd_update_file (host, file, val, opcode_ds_def, opcode_ds_num);
435 }
437 static void traffic_submit (unsigned int queries, unsigned int replies)
438 {
439 char buffer[64];
440 int status;
442 status = snprintf (buffer, 64, "N:%u:%u", queries, replies);
443 if ((status < 1) || (status >= 64))
444 return;
446 plugin_submit ("dns_traffic", "-", buffer);
447 }
449 static void qtype_submit (int qtype, unsigned int counter)
450 {
451 char inst[32];
452 char buffer[32];
453 int status;
455 strncpy (inst, qtype_str (qtype), 32);
456 inst[31] = '\0';
458 status = snprintf (buffer, 32, "N:%u", counter);
459 if ((status < 1) || (status >= 32))
460 return;
462 plugin_submit ("dns_qtype", inst, buffer);
463 }
465 static void rcode_submit (int rcode, unsigned int counter)
466 {
467 char inst[32];
468 char buffer[32];
469 int status;
471 strncpy (inst, rcode_str (rcode), 32);
472 inst[31] = '\0';
474 status = snprintf (buffer, 32, "N:%u", counter);
475 if ((status < 1) || (status >= 32))
476 return;
478 plugin_submit ("dns_rcode", inst, buffer);
479 }
481 static void opcode_submit (int opcode, unsigned int counter)
482 {
483 char inst[32];
484 char buffer[32];
485 int status;
487 strncpy (inst, opcode_str (opcode), 32);
488 inst[31] = '\0';
490 status = snprintf (buffer, 32, "N:%u", counter);
491 if ((status < 1) || (status >= 32))
492 return;
494 plugin_submit ("dns_opcode", inst, buffer);
495 }
497 #if NAMED_HAVE_READ
498 static void dns_read (void)
499 {
500 unsigned int keys[T_MAX];
501 unsigned int values[T_MAX];
502 int len;
503 int i;
505 counter_list_t *ptr;
507 pthread_mutex_lock (&traffic_mutex);
508 values[0] = tr_queries;
509 values[1] = tr_responses;
510 pthread_mutex_unlock (&traffic_mutex);
511 traffic_submit (values[0], values[1]);
513 pthread_mutex_lock (&qtype_mutex);
514 for (ptr = qtype_list, len = 0;
515 (ptr != NULL) && (len < T_MAX);
516 ptr = ptr->next, len++)
517 {
518 keys[len] = ptr->key;
519 values[len] = ptr->value;
520 }
521 pthread_mutex_unlock (&qtype_mutex);
523 for (i = 0; i < len; i++)
524 {
525 DBG ("qtype = %u; counter = %u;", keys[i], values[i]);
526 qtype_submit (keys[i], values[i]);
527 }
529 pthread_mutex_lock (&opcode_mutex);
530 for (ptr = opcode_list, len = 0;
531 (ptr != NULL) && (len < T_MAX);
532 ptr = ptr->next, len++)
533 {
534 keys[len] = ptr->key;
535 values[len] = ptr->value;
536 }
537 pthread_mutex_unlock (&opcode_mutex);
539 for (i = 0; i < len; i++)
540 {
541 DBG ("opcode = %u; counter = %u;", keys[i], values[i]);
542 opcode_submit (keys[i], values[i]);
543 }
545 pthread_mutex_lock (&rcode_mutex);
546 for (ptr = rcode_list, len = 0;
547 (ptr != NULL) && (len < T_MAX);
548 ptr = ptr->next, len++)
549 {
550 keys[len] = ptr->key;
551 values[len] = ptr->value;
552 }
553 pthread_mutex_unlock (&rcode_mutex);
555 for (i = 0; i < len; i++)
556 {
557 DBG ("rcode = %u; counter = %u;", keys[i], values[i]);
558 rcode_submit (keys[i], values[i]);
559 }
560 }
561 #else /* if !NAMED_HAVE_READ */
562 # define dns_read NULL
563 #endif
565 void module_register (void)
566 {
567 plugin_register (MODULE_NAME, dns_init, dns_read, NULL);
568 plugin_register ("dns_traffic", NULL, NULL, traffic_write);
569 plugin_register ("dns_qtype", NULL, NULL, qtype_write);
570 plugin_register ("dns_rcode", NULL, NULL, rcode_write);
571 plugin_register ("dns_opcode", NULL, NULL, opcode_write);
572 cf_register (MODULE_NAME, dns_config, config_keys, config_keys_num);
573 }
575 #undef MODULE_NAME