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diff --git a/src/service/dns/gnunet-dns-monitor.c b/src/service/dns/gnunet-dns-monitor.c
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1/*
2 This file is part of GNUnet.
3 Copyright (C) 2011 GNUnet e.V.
4
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
9
10 GNUnet 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 Affero General Public License for more details.
14
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
17
18 SPDX-License-Identifier: AGPL3.0-or-later
19 */
20
21/**
22 * @file src/dns/gnunet-dns-monitor.c
23 * @brief Tool to monitor DNS queries
24 * @author Christian Grothoff
25 */
26
27#include "platform.h"
28#include "gnunet_util_lib.h"
29#include "gnunet_dns_service.h"
30
31/**
32 * Handle to transport service.
33 */
34static struct GNUNET_DNS_Handle *handle;
35
36/**
37 * Option -i.
38 */
39static int inbound_only;
40
41/**
42 * Option -o.
43 */
44static int outbound_only;
45
46/**
47 * Global return value (0 success).
48 */
49static int ret;
50
51/**
52 * Selected level of verbosity.
53 */
54static unsigned int verbosity;
55
56
57/**
58 * Convert numeric DNS record type to a string.
59 *
60 * @param type type to convert
61 * @return type as string, only valid until the next call to this function
62 */
63static const char *
64get_type (uint16_t type)
65{
66 static char buf[6];
67
68 switch (type)
69 {
70 case GNUNET_DNSPARSER_TYPE_A: return "A";
71
72 case GNUNET_DNSPARSER_TYPE_NS: return "NS";
73
74 case GNUNET_DNSPARSER_TYPE_CNAME: return "CNAME";
75
76 case GNUNET_DNSPARSER_TYPE_SOA: return "SOA";
77
78 case GNUNET_DNSPARSER_TYPE_PTR: return "PTR";
79
80 case GNUNET_DNSPARSER_TYPE_MX: return "MX";
81
82 case GNUNET_DNSPARSER_TYPE_TXT: return "TXT";
83
84 case GNUNET_DNSPARSER_TYPE_AAAA: return "AAAA";
85
86 case GNUNET_DNSPARSER_TYPE_SRV: return "SRV";
87 }
88 GNUNET_snprintf (buf, sizeof(buf), "%u", (unsigned int) type);
89 return buf;
90}
91
92
93/**
94 * Convert numeric DNS record class to a string.
95 *
96 * @param class class to convert
97 * @return class as string, only valid until the next call to this function
98 */
99static const char *
100get_class (uint16_t class)
101{
102 static char buf[6];
103
104 switch (class)
105 {
106 case GNUNET_TUN_DNS_CLASS_INTERNET: return "IN";
107
108 case GNUNET_TUN_DNS_CLASS_CHAOS: return "CHAOS";
109
110 case GNUNET_TUN_DNS_CLASS_HESIOD: return "HESIOD";
111 }
112 GNUNET_snprintf (buf, sizeof(buf), "%u", (unsigned int) class);
113 return buf;
114}
115
116
117/**
118 * Output the given DNS query to stdout.
119 *
120 * @param query query to display.
121 */
122static void
123display_query (const struct GNUNET_DNSPARSER_Query *query)
124{
125 fprintf (stdout,
126 "\t\t%s %s: %s\n",
127 get_class (query->dns_traffic_class),
128 get_type (query->type),
129 query->name);
130}
131
132
133/**
134 * Output the given DNS record to stdout.
135 *
136 * @param record record to display.
137 */
138static void
139display_record (const struct GNUNET_DNSPARSER_Record *record)
140{
141 const char *format;
142 char buf[INET6_ADDRSTRLEN];
143 char *tmp;
144
145 tmp = NULL;
146 switch (record->type)
147 {
148 case GNUNET_DNSPARSER_TYPE_A:
149 if (record->data.raw.data_len != sizeof(struct in_addr))
150 format = "<invalid>";
151 else
152 format = inet_ntop (AF_INET, record->data.raw.data, buf, sizeof(buf));
153 break;
154
155 case GNUNET_DNSPARSER_TYPE_AAAA:
156 if (record->data.raw.data_len != sizeof(struct in6_addr))
157 format = "<invalid>";
158 else
159 format = inet_ntop (AF_INET6, record->data.raw.data, buf, sizeof(buf));
160 break;
161
162 case GNUNET_DNSPARSER_TYPE_NS:
163 case GNUNET_DNSPARSER_TYPE_CNAME:
164 case GNUNET_DNSPARSER_TYPE_PTR:
165 format = record->data.hostname;
166 break;
167
168 case GNUNET_DNSPARSER_TYPE_SOA:
169 if (NULL == record->data.soa)
170 format = "<invalid>";
171 else
172 {
173 GNUNET_asprintf (&tmp,
174 "origin: %s, mail: %s, serial = %u, refresh = %u s, retry = %u s, expire = %u s, minimum = %u s",
175 record->data.soa->mname,
176 record->data.soa->rname,
177 (unsigned int) record->data.soa->serial,
178 (unsigned int) record->data.soa->refresh,
179 (unsigned int) record->data.soa->retry,
180 (unsigned int) record->data.soa->expire,
181 (unsigned int) record->data.soa->minimum_ttl);
182 format = tmp;
183 }
184 break;
185
186 case GNUNET_DNSPARSER_TYPE_MX:
187 if (record->data.mx == NULL)
188 format = "<invalid>";
189 else
190 {
191 GNUNET_asprintf (&tmp,
192 "%u: %s",
193 record->data.mx->preference,
194 record->data.mx->mxhost);
195 format = tmp;
196 }
197 break;
198
199 case GNUNET_DNSPARSER_TYPE_SRV:
200 if (NULL == record->data.srv)
201 format = "<invalid>";
202 else
203 {
204 GNUNET_asprintf (&tmp,
205 "priority %u, weight = %u, port = %u, target = %s",
206 (unsigned int) record->data.srv->priority,
207 (unsigned int) record->data.srv->weight,
208 (unsigned int) record->data.srv->port,
209 record->data.srv->target);
210 format = tmp;
211 }
212 break;
213
214 case GNUNET_DNSPARSER_TYPE_TXT:
215 GNUNET_asprintf (&tmp,
216 "%.*s",
217 (unsigned int) record->data.raw.data_len,
218 (char*) record->data.raw.data);
219 format = tmp;
220 break;
221
222 default:
223 format = "<payload>";
224 break;
225 }
226 fprintf (stdout,
227 "\t\t%s %s: %s = %s (%u s)\n",
228 get_class (record->dns_traffic_class),
229 get_type (record->type),
230 record->name,
231 format,
232 (unsigned int) (GNUNET_TIME_absolute_get_remaining (
233 record->expiration_time).rel_value_us / 1000LL
234 / 1000LL));
235 GNUNET_free (tmp);
236}
237
238
239/**
240 * Signature of a function that is called whenever the DNS service
241 * encounters a DNS request and needs to do something with it. The
242 * function has then the chance to generate or modify the response by
243 * calling one of the three "GNUNET_DNS_request_*" continuations.
244 *
245 * When a request is intercepted, this function is called first to
246 * give the client a chance to do the complete address resolution;
247 * "rdata" will be NULL for this first call for a DNS request, unless
248 * some other client has already filled in a response.
249 *
250 * If multiple clients exist, all of them are called before the global
251 * DNS. The global DNS is only called if all of the clients'
252 * functions call GNUNET_DNS_request_forward. Functions that call
253 * GNUNET_DNS_request_forward will be called again before a final
254 * response is returned to the application. If any of the clients'
255 * functions call GNUNET_DNS_request_drop, the response is dropped.
256 *
257 * @param cls closure
258 * @param rh request handle to user for reply
259 * @param request_length number of bytes in request
260 * @param request udp payload of the DNS request
261 */
262static void
263display_request (void *cls,
264 struct GNUNET_DNS_RequestHandle *rh,
265 size_t request_length,
266 const char *request)
267{
268 static const char *return_codes[] = {
269 "No error", "Format error", "Server failure", "Name error",
270 "Not implemented", "Refused", "YXDomain", "YXRRset",
271 "NXRRset", "NOT AUTH", "NOT ZONE", "<invalid>",
272 "<invalid>", "<invalid>", "<invalid>", "<invalid>"
273 };
274 static const char *op_codes[] = {
275 "Query", "Inverse query", "Status", "<invalid>",
276 "<invalid>", "<invalid>", "<invalid>", "<invalid>",
277 "<invalid>", "<invalid>", "<invalid>", "<invalid>",
278 "<invalid>", "<invalid>", "<invalid>", "<invalid>"
279 };
280 struct GNUNET_DNSPARSER_Packet *p;
281 unsigned int i;
282
283 p = GNUNET_DNSPARSER_parse (request, request_length);
284 if (NULL == p)
285 {
286 fprintf (stderr, "Received malformed DNS packet!\n");
287 // FIXME: drop instead?
288 GNUNET_DNS_request_forward (rh);
289 return;
290 }
291 fprintf (stdout,
292 "%s with ID: %5u Flags: %s%s%s%s%s%s, Return Code: %s, Opcode: %s\n",
293 p->flags.query_or_response ? "Response" : "Query",
294 p->id,
295 p->flags.recursion_desired ? "RD " : "",
296 p->flags.message_truncated ? "MT " : "",
297 p->flags.authoritative_answer ? "AA " : "",
298 p->flags.checking_disabled ? "CD " : "",
299 p->flags.authenticated_data ? "AD " : "",
300 p->flags.recursion_available ? "RA " : "",
301 return_codes[p->flags.return_code & 15],
302 op_codes[p->flags.opcode & 15]);
303 if (p->num_queries > 0)
304 fprintf (stdout,
305 "\tQueries:\n");
306 for (i = 0; i < p->num_queries; i++)
307 display_query (&p->queries[i]);
308
309 if (p->num_answers > 0)
310 fprintf (stdout,
311 "\tAnswers:\n");
312 for (i = 0; i < p->num_answers; i++)
313 display_record (&p->answers[i]);
314 fprintf (stdout, "\n");
315 GNUNET_DNSPARSER_free_packet (p);
316 GNUNET_DNS_request_forward (rh);
317}
318
319
320/**
321 * Shutdown.
322 */
323static void
324do_disconnect (void *cls)
325{
326 if (NULL != handle)
327 {
328 GNUNET_DNS_disconnect (handle);
329 handle = NULL;
330 }
331}
332
333
334/**
335 * Main function that will be run by the scheduler.
336 *
337 * @param cls closure
338 * @param args remaining command-line arguments
339 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
340 * @param cfg configuration
341 */
342static void
343run (void *cls, char *const *args, const char *cfgfile,
344 const struct GNUNET_CONFIGURATION_Handle *cfg)
345{
346 enum GNUNET_DNS_Flags flags;
347
348 flags = GNUNET_DNS_FLAG_REQUEST_MONITOR | GNUNET_DNS_FLAG_RESPONSE_MONITOR;
349 if (inbound_only | outbound_only)
350 flags = 0;
351 if (inbound_only)
352 flags |= GNUNET_DNS_FLAG_REQUEST_MONITOR;
353 if (outbound_only)
354 flags |= GNUNET_DNS_FLAG_RESPONSE_MONITOR;
355 handle =
356 GNUNET_DNS_connect (cfg,
357 flags,
358 &display_request,
359 NULL);
360 GNUNET_SCHEDULER_add_shutdown (&do_disconnect, NULL);
361}
362
363
364int
365main (int argc, char *const *argv)
366{
367 struct GNUNET_GETOPT_CommandLineOption options[] = {
368 GNUNET_GETOPT_option_flag ('i',
369 "inbound-only",
370 gettext_noop ("only monitor DNS queries"),
371 &inbound_only),
372
373 GNUNET_GETOPT_option_flag ('o',
374 "outbound-only",
375 gettext_noop ("only monitor DNS queries"),
376 &outbound_only),
377
378 GNUNET_GETOPT_option_verbose (&verbosity),
379 GNUNET_GETOPT_OPTION_END
380 };
381
382 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
383 return 2;
384 ret = (GNUNET_OK ==
385 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns-monitor",
386 gettext_noop
387 ("Monitor DNS queries."), options,
388 &run, NULL)) ? ret : 1;
389 GNUNET_free_nz ((void *) argv);
390 return ret;
391}
392
393
394/* end of gnunet-dns-monitor.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-26 05:33:22 +0000