diff options
Diffstat (limited to 'src/resolver/resolver_api.c')
-rw-r--r-- | src/resolver/resolver_api.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/src/resolver/resolver_api.c b/src/resolver/resolver_api.c new file mode 100644 index 000000000..27358996a --- /dev/null +++ b/src/resolver/resolver_api.c | |||
@@ -0,0 +1,468 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | (C) 2009 Christian Grothoff (and other contributing authors) | ||
4 | |||
5 | GNUnet is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU General Public License as published | ||
7 | by the Free Software Foundation; either version 2, or (at your | ||
8 | 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 | General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU General Public License | ||
16 | along with GNUnet; see the file COPYING. If not, write to the | ||
17 | Free Software Foundation, Inc., 59 Temple Place - Suite 330, | ||
18 | Boston, MA 02111-1307, USA. | ||
19 | */ | ||
20 | |||
21 | /** | ||
22 | * @file resolver/resolver_api.c | ||
23 | * @brief resolver for writing a tool | ||
24 | * @author Christian Grothoff | ||
25 | */ | ||
26 | #include "platform.h" | ||
27 | #include "gnunet_getopt_lib.h" | ||
28 | #include "gnunet_client_lib.h" | ||
29 | #include "gnunet_protocols.h" | ||
30 | #include "gnunet_resolver_service.h" | ||
31 | #include "gnunet_server_lib.h" | ||
32 | #include "resolver.h" | ||
33 | |||
34 | |||
35 | struct GetAddressContext | ||
36 | { | ||
37 | GNUNET_RESOLVER_AddressCallback callback; | ||
38 | void *cls; | ||
39 | struct GNUNET_RESOLVER_GetMessage *msg; | ||
40 | struct GNUNET_CLIENT_Connection *client; | ||
41 | struct GNUNET_TIME_Absolute timeout; | ||
42 | }; | ||
43 | |||
44 | |||
45 | |||
46 | /** | ||
47 | * Convert IP address to string without DNS resolution. | ||
48 | */ | ||
49 | static char * | ||
50 | no_resolve (const struct sockaddr *sa, socklen_t salen) | ||
51 | { | ||
52 | char *ret; | ||
53 | char inet4[INET_ADDRSTRLEN]; | ||
54 | char inet6[INET6_ADDRSTRLEN]; | ||
55 | |||
56 | if (salen < sizeof (struct sockaddr)) | ||
57 | return NULL; | ||
58 | switch (sa->sa_family) | ||
59 | { | ||
60 | case AF_INET: | ||
61 | if (salen != sizeof (struct sockaddr_in)) | ||
62 | return NULL; | ||
63 | inet_ntop (AF_INET, | ||
64 | &((struct sockaddr_in *) sa)->sin_addr, | ||
65 | inet4, INET_ADDRSTRLEN); | ||
66 | ret = GNUNET_strdup (inet4); | ||
67 | break; | ||
68 | case AF_INET6: | ||
69 | if (salen != sizeof (struct sockaddr_in6)) | ||
70 | return NULL; | ||
71 | inet_ntop (AF_INET6, | ||
72 | &((struct sockaddr_in6 *) sa)->sin6_addr, | ||
73 | inet6, INET6_ADDRSTRLEN); | ||
74 | ret = GNUNET_strdup (inet6); | ||
75 | break; | ||
76 | default: | ||
77 | ret = NULL; | ||
78 | break; | ||
79 | } | ||
80 | return ret; | ||
81 | } | ||
82 | |||
83 | |||
84 | static void | ||
85 | handle_address_response (void *cls, const struct GNUNET_MessageHeader *msg) | ||
86 | { | ||
87 | struct GetAddressContext *gac = cls; | ||
88 | uint16_t size; | ||
89 | const struct sockaddr *sa; | ||
90 | socklen_t salen; | ||
91 | |||
92 | |||
93 | if (msg == NULL) | ||
94 | { | ||
95 | GNUNET_log (GNUNET_ERROR_TYPE_INFO, | ||
96 | _("Timeout trying to resolve hostname.\n")); | ||
97 | gac->callback (gac->cls, NULL, 0); | ||
98 | GNUNET_CLIENT_disconnect (gac->client); | ||
99 | GNUNET_free (gac); | ||
100 | return; | ||
101 | } | ||
102 | if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type)) | ||
103 | { | ||
104 | GNUNET_break (0); | ||
105 | gac->callback (gac->cls, NULL, 0); | ||
106 | GNUNET_CLIENT_disconnect (gac->client); | ||
107 | GNUNET_free (gac); | ||
108 | return; | ||
109 | } | ||
110 | |||
111 | size = ntohs (msg->size); | ||
112 | if (size == sizeof (struct GNUNET_MessageHeader)) | ||
113 | { | ||
114 | #if DEBUG_RESOLVER | ||
115 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
116 | _("Received end message resolving hostname.\n")); | ||
117 | #endif | ||
118 | gac->callback (gac->cls, NULL, 0); | ||
119 | GNUNET_CLIENT_disconnect (gac->client); | ||
120 | GNUNET_free (gac); | ||
121 | return; | ||
122 | } | ||
123 | sa = (const struct sockaddr *) &msg[1]; | ||
124 | salen = size - sizeof (struct GNUNET_MessageHeader); | ||
125 | if (salen < sizeof (struct sockaddr)) | ||
126 | { | ||
127 | GNUNET_break (0); | ||
128 | gac->callback (gac->cls, NULL, 0); | ||
129 | GNUNET_CLIENT_disconnect (gac->client); | ||
130 | GNUNET_free (gac); | ||
131 | return; | ||
132 | } | ||
133 | #if DEBUG_RESOLVER | ||
134 | { | ||
135 | char *ips = no_resolve (sa, salen); | ||
136 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s'.\n"), ips); | ||
137 | GNUNET_free (ips); | ||
138 | } | ||
139 | #endif | ||
140 | gac->callback (gac->cls, sa, salen); | ||
141 | GNUNET_CLIENT_receive (gac->client, | ||
142 | &handle_address_response, | ||
143 | gac, | ||
144 | GNUNET_TIME_absolute_get_remaining (gac->timeout)); | ||
145 | } | ||
146 | |||
147 | |||
148 | static size_t | ||
149 | transmit_get_ip (void *cls, size_t size, void *buf) | ||
150 | { | ||
151 | struct GetAddressContext *actx = cls; | ||
152 | uint16_t ms; | ||
153 | |||
154 | if (buf == NULL) | ||
155 | { | ||
156 | /* timeout / error */ | ||
157 | GNUNET_free (actx->msg); | ||
158 | actx->callback (actx->cls, NULL, 0); | ||
159 | GNUNET_CLIENT_disconnect (actx->client); | ||
160 | GNUNET_free (actx); | ||
161 | return 0; | ||
162 | } | ||
163 | ms = ntohs (actx->msg->header.size); | ||
164 | GNUNET_assert (size >= ms); | ||
165 | memcpy (buf, actx->msg, ms); | ||
166 | GNUNET_free (actx->msg); | ||
167 | actx->msg = NULL; | ||
168 | GNUNET_CLIENT_receive (actx->client, | ||
169 | &handle_address_response, | ||
170 | actx, | ||
171 | GNUNET_TIME_absolute_get_remaining (actx->timeout)); | ||
172 | return ms; | ||
173 | } | ||
174 | |||
175 | |||
176 | |||
177 | /** | ||
178 | * Convert a string to one or more IP addresses. | ||
179 | * | ||
180 | * @param sched scheduler to use | ||
181 | * @param cfg configuration to use | ||
182 | * @param hostname the hostname to resolve | ||
183 | * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any" | ||
184 | * @param callback function to call with addresses | ||
185 | * @param cls closure for callback | ||
186 | * @param timeout how long to try resolving | ||
187 | */ | ||
188 | void | ||
189 | GNUNET_RESOLVER_ip_get (struct GNUNET_SCHEDULER_Handle *sched, | ||
190 | struct GNUNET_CONFIGURATION_Handle *cfg, | ||
191 | const char *hostname, | ||
192 | int domain, | ||
193 | struct GNUNET_TIME_Relative timeout, | ||
194 | GNUNET_RESOLVER_AddressCallback callback, void *cls) | ||
195 | { | ||
196 | struct GNUNET_CLIENT_Connection *client; | ||
197 | struct GNUNET_RESOLVER_GetMessage *msg; | ||
198 | struct GetAddressContext *actx; | ||
199 | size_t slen; | ||
200 | |||
201 | slen = strlen (hostname) + 1; | ||
202 | if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) > | ||
203 | GNUNET_SERVER_MAX_MESSAGE_SIZE) | ||
204 | { | ||
205 | GNUNET_break (0); | ||
206 | callback (cls, NULL, 0); | ||
207 | return; | ||
208 | } | ||
209 | client = GNUNET_CLIENT_connect (sched, "resolver", cfg); | ||
210 | if (client == NULL) | ||
211 | { | ||
212 | callback (cls, NULL, 0); | ||
213 | return; | ||
214 | } | ||
215 | msg = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_GetMessage) + slen); | ||
216 | msg->header.size = | ||
217 | htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + slen); | ||
218 | msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST); | ||
219 | msg->direction = htonl (GNUNET_NO); | ||
220 | msg->domain = htonl (domain); | ||
221 | memcpy (&msg[1], hostname, slen); | ||
222 | actx = GNUNET_malloc (sizeof (struct GetAddressContext)); | ||
223 | actx->callback = callback; | ||
224 | actx->cls = cls; | ||
225 | actx->client = client; | ||
226 | actx->timeout = GNUNET_TIME_relative_to_absolute (timeout); | ||
227 | actx->msg = msg; | ||
228 | |||
229 | #if DEBUG_RESOLVER | ||
230 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
231 | _("Resolver requests DNS resolution of hostname `%s'.\n"), | ||
232 | hostname); | ||
233 | #endif | ||
234 | if (NULL == | ||
235 | GNUNET_CLIENT_notify_transmit_ready (client, | ||
236 | slen + | ||
237 | sizeof (struct | ||
238 | GNUNET_RESOLVER_GetMessage), | ||
239 | timeout, &transmit_get_ip, actx)) | ||
240 | { | ||
241 | GNUNET_free (msg); | ||
242 | GNUNET_free (actx); | ||
243 | callback (cls, NULL, 0); | ||
244 | GNUNET_CLIENT_disconnect (client); | ||
245 | return; | ||
246 | } | ||
247 | } | ||
248 | |||
249 | |||
250 | struct GetHostnameContext | ||
251 | { | ||
252 | GNUNET_RESOLVER_HostnameCallback callback; | ||
253 | void *cls; | ||
254 | struct GNUNET_RESOLVER_GetMessage *msg; | ||
255 | struct GNUNET_CLIENT_Connection *client; | ||
256 | struct GNUNET_TIME_Absolute timeout; | ||
257 | }; | ||
258 | |||
259 | |||
260 | static void | ||
261 | handle_hostname_response (void *cls, const struct GNUNET_MessageHeader *msg) | ||
262 | { | ||
263 | struct GetHostnameContext *ghc = cls; | ||
264 | uint16_t size; | ||
265 | const char *hostname; | ||
266 | |||
267 | if (msg == NULL) | ||
268 | { | ||
269 | GNUNET_log (GNUNET_ERROR_TYPE_INFO, | ||
270 | _("Timeout trying to resolve IP address.\n")); | ||
271 | ghc->callback (ghc->cls, NULL); | ||
272 | GNUNET_CLIENT_disconnect (ghc->client); | ||
273 | GNUNET_free (ghc); | ||
274 | return; | ||
275 | } | ||
276 | size = ntohs (msg->size); | ||
277 | if (size == sizeof (struct GNUNET_MessageHeader)) | ||
278 | { | ||
279 | #if DEBUG_RESOLVER | ||
280 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
281 | _("Received end message resolving IP address.\n")); | ||
282 | #endif | ||
283 | ghc->callback (ghc->cls, NULL); | ||
284 | GNUNET_CLIENT_disconnect (ghc->client); | ||
285 | GNUNET_free (ghc); | ||
286 | return; | ||
287 | } | ||
288 | hostname = (const char *) &msg[1]; | ||
289 | if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0') | ||
290 | { | ||
291 | GNUNET_break (0); | ||
292 | ghc->callback (ghc->cls, NULL); | ||
293 | GNUNET_CLIENT_disconnect (ghc->client); | ||
294 | GNUNET_free (ghc); | ||
295 | return; | ||
296 | } | ||
297 | #if DEBUG_RESOLVER | ||
298 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
299 | _("Resolver returns `%s'.\n"), hostname); | ||
300 | #endif | ||
301 | ghc->callback (ghc->cls, hostname); | ||
302 | GNUNET_CLIENT_receive (ghc->client, | ||
303 | &handle_hostname_response, | ||
304 | ghc, | ||
305 | GNUNET_TIME_absolute_get_remaining (ghc->timeout)); | ||
306 | } | ||
307 | |||
308 | |||
309 | static size_t | ||
310 | transmit_get_hostname (void *cls, size_t size, void *buf) | ||
311 | { | ||
312 | struct GetHostnameContext *hctx = cls; | ||
313 | uint16_t msize; | ||
314 | |||
315 | if (buf == NULL) | ||
316 | { | ||
317 | GNUNET_free (hctx->msg); | ||
318 | hctx->callback (hctx->cls, NULL); | ||
319 | GNUNET_CLIENT_disconnect (hctx->client); | ||
320 | GNUNET_free (hctx); | ||
321 | return 0; | ||
322 | } | ||
323 | msize = ntohs (hctx->msg->header.size); | ||
324 | GNUNET_assert (size >= msize); | ||
325 | memcpy (buf, hctx->msg, msize); | ||
326 | GNUNET_free (hctx->msg); | ||
327 | hctx->msg = NULL; | ||
328 | GNUNET_CLIENT_receive (hctx->client, | ||
329 | &handle_hostname_response, | ||
330 | hctx, | ||
331 | GNUNET_TIME_absolute_get_remaining (hctx->timeout)); | ||
332 | return msize; | ||
333 | } | ||
334 | |||
335 | |||
336 | |||
337 | |||
338 | /** | ||
339 | * Get an IP address as a string. | ||
340 | * | ||
341 | * @param sched scheduler to use | ||
342 | * @param cfg configuration to use | ||
343 | * @param sa host address | ||
344 | * @param salen length of host address | ||
345 | * @param do_resolve use GNUNET_NO to return numeric hostname | ||
346 | * @param timeout how long to try resolving | ||
347 | * @param callback function to call with hostnames | ||
348 | * @param cls closure for callback | ||
349 | */ | ||
350 | void | ||
351 | GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched, | ||
352 | struct GNUNET_CONFIGURATION_Handle *cfg, | ||
353 | const struct sockaddr *sa, | ||
354 | socklen_t salen, | ||
355 | int do_resolve, | ||
356 | struct GNUNET_TIME_Relative timeout, | ||
357 | GNUNET_RESOLVER_HostnameCallback callback, | ||
358 | void *cls) | ||
359 | { | ||
360 | char *result; | ||
361 | struct GNUNET_CLIENT_Connection *client; | ||
362 | struct GNUNET_RESOLVER_GetMessage *msg; | ||
363 | struct GetHostnameContext *hctx; | ||
364 | |||
365 | if (GNUNET_NO == do_resolve) | ||
366 | { | ||
367 | result = no_resolve (sa, salen); | ||
368 | #if DEBUG_RESOLVER | ||
369 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
370 | _("Resolver returns `%s'.\n"), result); | ||
371 | #endif | ||
372 | callback (cls, result); | ||
373 | if (result != NULL) | ||
374 | { | ||
375 | GNUNET_free (result); | ||
376 | callback (cls, NULL); | ||
377 | } | ||
378 | return; | ||
379 | } | ||
380 | if (salen + sizeof (struct GNUNET_RESOLVER_GetMessage) > | ||
381 | GNUNET_SERVER_MAX_MESSAGE_SIZE) | ||
382 | { | ||
383 | GNUNET_break (0); | ||
384 | callback (cls, NULL); | ||
385 | return; | ||
386 | } | ||
387 | client = GNUNET_CLIENT_connect (sched, "resolver", cfg); | ||
388 | if (client == NULL) | ||
389 | { | ||
390 | callback (cls, NULL); | ||
391 | return; | ||
392 | } | ||
393 | msg = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_GetMessage) + salen); | ||
394 | msg->header.size = | ||
395 | htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + salen); | ||
396 | msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST); | ||
397 | msg->direction = htonl (GNUNET_YES); | ||
398 | msg->domain = htonl (sa->sa_family); | ||
399 | memcpy (&msg[1], sa, salen); | ||
400 | #if DEBUG_RESOLVER | ||
401 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
402 | _("Resolver requests DNS resolution of IP address.\n")); | ||
403 | #endif | ||
404 | hctx = GNUNET_malloc (sizeof (struct GetHostnameContext)); | ||
405 | hctx->callback = callback; | ||
406 | hctx->cls = cls; | ||
407 | hctx->client = client; | ||
408 | hctx->timeout = GNUNET_TIME_relative_to_absolute (timeout); | ||
409 | hctx->msg = msg; | ||
410 | if (NULL == | ||
411 | GNUNET_CLIENT_notify_transmit_ready (client, | ||
412 | sizeof (struct | ||
413 | GNUNET_RESOLVER_GetMessage) | ||
414 | + salen, timeout, | ||
415 | &transmit_get_hostname, hctx)) | ||
416 | { | ||
417 | GNUNET_free (msg); | ||
418 | callback (cls, NULL); | ||
419 | GNUNET_CLIENT_disconnect (client); | ||
420 | GNUNET_free (hctx); | ||
421 | } | ||
422 | } | ||
423 | |||
424 | /** | ||
425 | * Maximum supported length of hostname | ||
426 | */ | ||
427 | #define MAX_HOSTNAME 1024 | ||
428 | |||
429 | |||
430 | /** | ||
431 | * Resolve our hostname to an IP address. | ||
432 | * | ||
433 | * @param sched scheduler to use | ||
434 | * @param cfg configuration to use | ||
435 | * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any" | ||
436 | * @param callback function to call with addresses | ||
437 | * @param cls closure for callback | ||
438 | * @param timeout how long to try resolving | ||
439 | */ | ||
440 | void | ||
441 | GNUNET_RESOLVER_hostname_resolve (struct GNUNET_SCHEDULER_Handle *sched, | ||
442 | struct GNUNET_CONFIGURATION_Handle *cfg, | ||
443 | int domain, | ||
444 | struct GNUNET_TIME_Relative timeout, | ||
445 | GNUNET_RESOLVER_AddressCallback callback, | ||
446 | void *cls) | ||
447 | { | ||
448 | char hostname[MAX_HOSTNAME]; | ||
449 | |||
450 | if (0 != gethostname (hostname, sizeof (hostname) - 1)) | ||
451 | { | ||
452 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | | ||
453 | GNUNET_ERROR_TYPE_BULK, "gethostname"); | ||
454 | callback (cls, NULL, 0); | ||
455 | return; | ||
456 | } | ||
457 | #if DEBUG_RESOLVER | ||
458 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
459 | _("Resolving our hostname `%s'\n"), hostname); | ||
460 | #endif | ||
461 | GNUNET_RESOLVER_ip_get (sched, | ||
462 | cfg, hostname, domain, timeout, callback, cls); | ||
463 | } | ||
464 | |||
465 | |||
466 | |||
467 | |||
468 | /* end of resolver_api.c */ | ||