e23a2bb21b343b3dd37ae3a7f20e7ac77a496de3
1 /**
2 * collectd - src/dns.c
3 * Copyright (C) 2006-2011 Florian octo Forster
4 * Copyright (C) 2009 Mirko Buffoni
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; only version 2 of the License is applicable.
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 collectd.org>
21 * Mirko Buffoni <briareos at eswat.org>
22 **/
24 #define _DEFAULT_SOURCE
25 #define _BSD_SOURCE
27 #include "collectd.h"
29 #include "common.h"
30 #include "plugin.h"
32 #include "utils_dns.h"
33 #include <poll.h>
35 #include <pcap.h>
37 /*
38 * Private data types
39 */
40 struct counter_list_s
41 {
42 unsigned int key;
43 unsigned int value;
44 struct counter_list_s *next;
45 };
46 typedef struct counter_list_s counter_list_t;
48 /*
49 * Private variables
50 */
51 static const char *config_keys[] =
52 {
53 "Interface",
54 "IgnoreSource",
55 "SelectNumericQueryTypes"
56 };
57 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
58 static int select_numeric_qtype = 1;
60 #define PCAP_SNAPLEN 1460
61 static char *pcap_device = NULL;
63 static derive_t tr_queries;
64 static derive_t tr_responses;
65 static counter_list_t *qtype_list;
66 static counter_list_t *opcode_list;
67 static counter_list_t *rcode_list;
69 static pthread_t listen_thread;
70 static int listen_thread_init = 0;
71 /* The `traffic' mutex if for `tr_queries' and `tr_responses' */
72 static pthread_mutex_t traffic_mutex = PTHREAD_MUTEX_INITIALIZER;
73 static pthread_mutex_t qtype_mutex = PTHREAD_MUTEX_INITIALIZER;
74 static pthread_mutex_t opcode_mutex = PTHREAD_MUTEX_INITIALIZER;
75 static pthread_mutex_t rcode_mutex = PTHREAD_MUTEX_INITIALIZER;
77 /*
78 * Private functions
79 */
80 static counter_list_t *counter_list_search (counter_list_t **list, unsigned int key)
81 {
82 counter_list_t *entry;
84 for (entry = *list; entry != NULL; entry = entry->next)
85 if (entry->key == key)
86 break;
88 return (entry);
89 }
91 static counter_list_t *counter_list_create (counter_list_t **list,
92 unsigned int key, unsigned int value)
93 {
94 counter_list_t *entry;
96 entry = calloc (1, sizeof (*entry));
97 if (entry == NULL)
98 return (NULL);
100 entry->key = key;
101 entry->value = value;
103 if (*list == NULL)
104 {
105 *list = entry;
106 }
107 else
108 {
109 counter_list_t *last;
111 last = *list;
112 while (last->next != NULL)
113 last = last->next;
115 last->next = entry;
116 }
118 return (entry);
119 }
121 static void counter_list_add (counter_list_t **list,
122 unsigned int key, unsigned int increment)
123 {
124 counter_list_t *entry;
126 entry = counter_list_search (list, key);
128 if (entry != NULL)
129 {
130 entry->value += increment;
131 }
132 else
133 {
134 counter_list_create (list, key, increment);
135 }
136 }
138 static int dns_config (const char *key, const char *value)
139 {
140 if (strcasecmp (key, "Interface") == 0)
141 {
142 if (pcap_device != NULL)
143 free (pcap_device);
144 if ((pcap_device = strdup (value)) == NULL)
145 return (1);
146 }
147 else if (strcasecmp (key, "IgnoreSource") == 0)
148 {
149 if (value != NULL)
150 ignore_list_add_name (value);
151 }
152 else if (strcasecmp (key, "SelectNumericQueryTypes") == 0)
153 {
154 if ((value != NULL) && IS_FALSE (value))
155 select_numeric_qtype = 0;
156 else
157 select_numeric_qtype = 1;
158 }
159 else
160 {
161 return (-1);
162 }
164 return (0);
165 }
167 static void dns_child_callback (const rfc1035_header_t *dns)
168 {
169 if (dns->qr == 0)
170 {
171 /* This is a query */
172 int skip = 0;
173 if (!select_numeric_qtype)
174 {
175 const char *str = qtype_str(dns->qtype);
176 if ((str == NULL) || (str[0] == '#'))
177 skip = 1;
178 }
180 pthread_mutex_lock (&traffic_mutex);
181 tr_queries += dns->length;
182 pthread_mutex_unlock (&traffic_mutex);
184 if (skip == 0)
185 {
186 pthread_mutex_lock (&qtype_mutex);
187 counter_list_add (&qtype_list, dns->qtype, 1);
188 pthread_mutex_unlock (&qtype_mutex);
189 }
190 }
191 else
192 {
193 /* This is a reply */
194 pthread_mutex_lock (&traffic_mutex);
195 tr_responses += dns->length;
196 pthread_mutex_unlock (&traffic_mutex);
198 pthread_mutex_lock (&rcode_mutex);
199 counter_list_add (&rcode_list, dns->rcode, 1);
200 pthread_mutex_unlock (&rcode_mutex);
201 }
203 /* FIXME: Are queries, replies or both interesting? */
204 pthread_mutex_lock (&opcode_mutex);
205 counter_list_add (&opcode_list, dns->opcode, 1);
206 pthread_mutex_unlock (&opcode_mutex);
207 }
209 static int dns_run_pcap_loop (void)
210 {
211 pcap_t *pcap_obj;
212 char pcap_error[PCAP_ERRBUF_SIZE];
213 struct bpf_program fp = { 0 };
215 int status;
217 /* Don't block any signals */
218 {
219 sigset_t sigmask;
220 sigemptyset (&sigmask);
221 pthread_sigmask (SIG_SETMASK, &sigmask, NULL);
222 }
224 /* Passing `pcap_device == NULL' is okay and the same as passign "any" */
225 DEBUG ("dns plugin: Creating PCAP object..");
226 pcap_obj = pcap_open_live ((pcap_device != NULL) ? pcap_device : "any",
227 PCAP_SNAPLEN,
228 0 /* Not promiscuous */,
229 (int) CDTIME_T_TO_MS (plugin_get_interval () / 2),
230 pcap_error);
231 if (pcap_obj == NULL)
232 {
233 ERROR ("dns plugin: Opening interface `%s' "
234 "failed: %s",
235 (pcap_device != NULL) ? pcap_device : "any",
236 pcap_error);
237 return (PCAP_ERROR);
238 }
240 status = pcap_compile (pcap_obj, &fp, "udp port 53", 1, 0);
241 if (status < 0)
242 {
243 ERROR ("dns plugin: pcap_compile failed: %s",
244 pcap_statustostr (status));
245 return (status);
246 }
248 status = pcap_setfilter (pcap_obj, &fp);
249 if (status < 0)
250 {
251 ERROR ("dns plugin: pcap_setfilter failed: %s",
252 pcap_statustostr (status));
253 return (status);
254 }
256 DEBUG ("dns plugin: PCAP object created.");
258 dnstop_set_pcap_obj (pcap_obj);
259 dnstop_set_callback (dns_child_callback);
261 status = pcap_loop (pcap_obj,
262 -1 /* loop forever */,
263 handle_pcap /* callback */,
264 NULL /* user data */);
265 INFO ("dns plugin: pcap_loop exited with status %i.", status);
266 /* We need to handle "PCAP_ERROR" specially because libpcap currently
267 * doesn't return PCAP_ERROR_IFACE_NOT_UP for compatibility reasons. */
268 if (status == PCAP_ERROR)
269 status = PCAP_ERROR_IFACE_NOT_UP;
271 pcap_close (pcap_obj);
272 return (status);
273 } /* int dns_run_pcap_loop */
275 static int dns_sleep_one_interval (void) /* {{{ */
276 {
277 cdtime_t interval;
278 struct timespec ts = { 0, 0 };
279 int status = 0;
281 interval = plugin_get_interval ();
282 CDTIME_T_TO_TIMESPEC (interval, &ts);
284 while (42)
285 {
286 struct timespec rem = { 0, 0 };
288 status = nanosleep (&ts, &rem);
289 if (status == 0)
290 break;
291 else if ((errno == EINTR) || (errno == EAGAIN))
292 {
293 ts = rem;
294 continue;
295 }
296 else
297 break;
298 }
300 return (status);
301 } /* }}} int dns_sleep_one_interval */
303 static void *dns_child_loop (__attribute__((unused)) void *dummy) /* {{{ */
304 {
305 int status;
307 while (42)
308 {
309 status = dns_run_pcap_loop ();
310 if (status != PCAP_ERROR_IFACE_NOT_UP)
311 break;
313 dns_sleep_one_interval ();
314 }
316 if (status != PCAP_ERROR_BREAK)
317 ERROR ("dns plugin: PCAP returned error %s.",
318 pcap_statustostr (status));
320 listen_thread_init = 0;
321 return (NULL);
322 } /* }}} void *dns_child_loop */
324 static int dns_init (void)
325 {
326 /* clean up an old thread */
327 int status;
329 pthread_mutex_lock (&traffic_mutex);
330 tr_queries = 0;
331 tr_responses = 0;
332 pthread_mutex_unlock (&traffic_mutex);
334 if (listen_thread_init != 0)
335 return (-1);
337 status = plugin_thread_create (&listen_thread, NULL, dns_child_loop,
338 (void *) 0);
339 if (status != 0)
340 {
341 char errbuf[1024];
342 ERROR ("dns plugin: pthread_create failed: %s",
343 sstrerror (errno, errbuf, sizeof (errbuf)));
344 return (-1);
345 }
347 listen_thread_init = 1;
349 return (0);
350 } /* int dns_init */
352 static void submit_derive (const char *type, const char *type_instance,
353 derive_t value)
354 {
355 value_t values[1];
356 value_list_t vl = VALUE_LIST_INIT;
358 values[0].derive = value;
360 vl.values = values;
361 vl.values_len = 1;
362 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
363 sstrncpy (vl.plugin, "dns", sizeof (vl.plugin));
364 sstrncpy (vl.type, type, sizeof (vl.type));
365 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
367 plugin_dispatch_values (&vl);
368 } /* void submit_derive */
370 static void submit_octets (derive_t queries, derive_t responses)
371 {
372 value_t values[2];
373 value_list_t vl = VALUE_LIST_INIT;
375 values[0].derive = queries;
376 values[1].derive = responses;
378 vl.values = values;
379 vl.values_len = 2;
380 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
381 sstrncpy (vl.plugin, "dns", sizeof (vl.plugin));
382 sstrncpy (vl.type, "dns_octets", sizeof (vl.type));
384 plugin_dispatch_values (&vl);
385 } /* void submit_octets */
387 static int dns_read (void)
388 {
389 unsigned int keys[T_MAX];
390 unsigned int values[T_MAX];
391 int len;
393 counter_list_t *ptr;
395 pthread_mutex_lock (&traffic_mutex);
396 values[0] = tr_queries;
397 values[1] = tr_responses;
398 pthread_mutex_unlock (&traffic_mutex);
400 if ((values[0] != 0) || (values[1] != 0))
401 submit_octets (values[0], values[1]);
403 pthread_mutex_lock (&qtype_mutex);
404 for (ptr = qtype_list, len = 0;
405 (ptr != NULL) && (len < T_MAX);
406 ptr = ptr->next, len++)
407 {
408 keys[len] = ptr->key;
409 values[len] = ptr->value;
410 }
411 pthread_mutex_unlock (&qtype_mutex);
413 for (int i = 0; i < len; i++)
414 {
415 DEBUG ("dns plugin: qtype = %u; counter = %u;", keys[i], values[i]);
416 submit_derive ("dns_qtype", qtype_str (keys[i]), values[i]);
417 }
419 pthread_mutex_lock (&opcode_mutex);
420 for (ptr = opcode_list, len = 0;
421 (ptr != NULL) && (len < T_MAX);
422 ptr = ptr->next, len++)
423 {
424 keys[len] = ptr->key;
425 values[len] = ptr->value;
426 }
427 pthread_mutex_unlock (&opcode_mutex);
429 for (int i = 0; i < len; i++)
430 {
431 DEBUG ("dns plugin: opcode = %u; counter = %u;", keys[i], values[i]);
432 submit_derive ("dns_opcode", opcode_str (keys[i]), values[i]);
433 }
435 pthread_mutex_lock (&rcode_mutex);
436 for (ptr = rcode_list, len = 0;
437 (ptr != NULL) && (len < T_MAX);
438 ptr = ptr->next, len++)
439 {
440 keys[len] = ptr->key;
441 values[len] = ptr->value;
442 }
443 pthread_mutex_unlock (&rcode_mutex);
445 for (int i = 0; i < len; i++)
446 {
447 DEBUG ("dns plugin: rcode = %u; counter = %u;", keys[i], values[i]);
448 submit_derive ("dns_rcode", rcode_str (keys[i]), values[i]);
449 }
451 return (0);
452 } /* int dns_read */
454 void module_register (void)
455 {
456 plugin_register_config ("dns", dns_config, config_keys, config_keys_num);
457 plugin_register_init ("dns", dns_init);
458 plugin_register_read ("dns", dns_read);
459 } /* void module_register */