diff options
Diffstat (limited to 'src/service/nat/nat_api.c')
-rw-r--r-- | src/service/nat/nat_api.c | 702 |
1 files changed, 702 insertions, 0 deletions
diff --git a/src/service/nat/nat_api.c b/src/service/nat/nat_api.c new file mode 100644 index 000000000..31f8f388d --- /dev/null +++ b/src/service/nat/nat_api.c | |||
@@ -0,0 +1,702 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2007-2017 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 | * @author Christian Grothoff | ||
23 | * @author Milan Bouchet-Valat | ||
24 | * | ||
25 | * @file nat/nat_api.c | ||
26 | * Service for handling UPnP and NAT-PMP port forwarding | ||
27 | * and external IP address retrieval | ||
28 | */ | ||
29 | #include "platform.h" | ||
30 | #include "gnunet_nat_service.h" | ||
31 | #include "nat.h" | ||
32 | #include "nat_stun.h" | ||
33 | |||
34 | |||
35 | /** | ||
36 | * Entry in DLL of addresses of this peer. | ||
37 | */ | ||
38 | struct AddrEntry | ||
39 | { | ||
40 | /** | ||
41 | * DLL. | ||
42 | */ | ||
43 | struct AddrEntry *next; | ||
44 | |||
45 | /** | ||
46 | * DLL. | ||
47 | */ | ||
48 | struct AddrEntry *prev; | ||
49 | |||
50 | /** | ||
51 | * Place where the application can store data (on add, | ||
52 | * and retrieve on remove). | ||
53 | */ | ||
54 | void *app_ctx; | ||
55 | |||
56 | /** | ||
57 | * Address class of the address. | ||
58 | */ | ||
59 | enum GNUNET_NAT_AddressClass ac; | ||
60 | |||
61 | /** | ||
62 | * Number of bytes that follow. | ||
63 | */ | ||
64 | socklen_t addrlen; | ||
65 | }; | ||
66 | |||
67 | |||
68 | /** | ||
69 | * Handle for active NAT registrations. | ||
70 | */ | ||
71 | struct GNUNET_NAT_Handle | ||
72 | { | ||
73 | /** | ||
74 | * Configuration we use. | ||
75 | */ | ||
76 | const struct GNUNET_CONFIGURATION_Handle *cfg; | ||
77 | |||
78 | /** | ||
79 | * Message queue for communicating with the NAT service. | ||
80 | */ | ||
81 | struct GNUNET_MQ_Handle *mq; | ||
82 | |||
83 | /** | ||
84 | * Our registration message. | ||
85 | */ | ||
86 | struct GNUNET_MessageHeader *reg; | ||
87 | |||
88 | /** | ||
89 | * Head of address DLL. | ||
90 | */ | ||
91 | struct AddrEntry *ae_head; | ||
92 | |||
93 | /** | ||
94 | * Tail of address DLL. | ||
95 | */ | ||
96 | struct AddrEntry *ae_tail; | ||
97 | |||
98 | /** | ||
99 | * Function to call when our addresses change. | ||
100 | */ | ||
101 | GNUNET_NAT_AddressCallback address_callback; | ||
102 | |||
103 | /** | ||
104 | * Function to call when another peer requests connection reversal. | ||
105 | */ | ||
106 | GNUNET_NAT_ReversalCallback reversal_callback; | ||
107 | |||
108 | /** | ||
109 | * Closure for the various callbacks. | ||
110 | */ | ||
111 | void *callback_cls; | ||
112 | |||
113 | /** | ||
114 | * Task scheduled to reconnect to the service. | ||
115 | */ | ||
116 | struct GNUNET_SCHEDULER_Task *reconnect_task; | ||
117 | |||
118 | /** | ||
119 | * How long to wait until we reconnect. | ||
120 | */ | ||
121 | struct GNUNET_TIME_Relative reconnect_delay; | ||
122 | }; | ||
123 | |||
124 | |||
125 | /** | ||
126 | * Task to connect to the NAT service. | ||
127 | * | ||
128 | * @param cls our `struct GNUNET_NAT_Handle *` | ||
129 | */ | ||
130 | static void | ||
131 | do_connect (void *cls); | ||
132 | |||
133 | |||
134 | /** | ||
135 | * Task to connect to the NAT service. | ||
136 | * | ||
137 | * @param nh handle to reconnect | ||
138 | */ | ||
139 | static void | ||
140 | reconnect (struct GNUNET_NAT_Handle *nh) | ||
141 | { | ||
142 | struct AddrEntry *ae; | ||
143 | |||
144 | if (NULL != nh->mq) | ||
145 | { | ||
146 | GNUNET_MQ_destroy (nh->mq); | ||
147 | nh->mq = NULL; | ||
148 | } | ||
149 | while (NULL != (ae = nh->ae_head)) | ||
150 | { | ||
151 | GNUNET_CONTAINER_DLL_remove (nh->ae_head, nh->ae_tail, ae); | ||
152 | nh->address_callback (nh->callback_cls, | ||
153 | &ae->app_ctx, | ||
154 | GNUNET_NO, | ||
155 | ae->ac, | ||
156 | (const struct sockaddr *) &ae[1], | ||
157 | ae->addrlen); | ||
158 | GNUNET_free (ae); | ||
159 | } | ||
160 | nh->reconnect_delay = GNUNET_TIME_STD_BACKOFF (nh->reconnect_delay); | ||
161 | nh->reconnect_task = | ||
162 | GNUNET_SCHEDULER_add_delayed (nh->reconnect_delay, &do_connect, nh); | ||
163 | } | ||
164 | |||
165 | |||
166 | /** | ||
167 | * Check connection reversal request. | ||
168 | * | ||
169 | * @param cls our `struct GNUNET_NAT_Handle` | ||
170 | * @param crm the message | ||
171 | * @return #GNUNET_OK if @a crm is well-formed | ||
172 | */ | ||
173 | static int | ||
174 | check_connection_reversal_request ( | ||
175 | void *cls, | ||
176 | const struct GNUNET_NAT_ConnectionReversalRequestedMessage *crm) | ||
177 | { | ||
178 | if (ntohs (crm->header.size) != sizeof(*crm) + sizeof(struct sockaddr_in)) | ||
179 | { | ||
180 | GNUNET_break (0); | ||
181 | return GNUNET_SYSERR; | ||
182 | } | ||
183 | return GNUNET_OK; | ||
184 | } | ||
185 | |||
186 | |||
187 | /** | ||
188 | * Handle connection reversal request. | ||
189 | * | ||
190 | * @param cls our `struct GNUNET_NAT_Handle` | ||
191 | * @param crm the message | ||
192 | */ | ||
193 | static void | ||
194 | handle_connection_reversal_request ( | ||
195 | void *cls, | ||
196 | const struct GNUNET_NAT_ConnectionReversalRequestedMessage *crm) | ||
197 | { | ||
198 | struct GNUNET_NAT_Handle *nh = cls; | ||
199 | |||
200 | nh->reversal_callback (nh->callback_cls, | ||
201 | (const struct sockaddr *) &crm[1], | ||
202 | sizeof(struct sockaddr_in)); | ||
203 | } | ||
204 | |||
205 | |||
206 | /** | ||
207 | * Check address change notification. | ||
208 | * | ||
209 | * @param cls our `struct GNUNET_NAT_Handle` | ||
210 | * @param acn the message | ||
211 | * @return #GNUNET_OK if @a crm is well-formed | ||
212 | */ | ||
213 | static int | ||
214 | check_address_change_notification ( | ||
215 | void *cls, | ||
216 | const struct GNUNET_NAT_AddressChangeNotificationMessage *acn) | ||
217 | { | ||
218 | size_t alen = ntohs (acn->header.size) - sizeof(*acn); | ||
219 | |||
220 | switch (alen) | ||
221 | { | ||
222 | case sizeof(struct sockaddr_in): { | ||
223 | const struct sockaddr_in *s4 = (const struct sockaddr_in *) &acn[1]; | ||
224 | if (AF_INET != s4->sin_family) | ||
225 | { | ||
226 | GNUNET_break (0); | ||
227 | return GNUNET_SYSERR; | ||
228 | } | ||
229 | } | ||
230 | break; | ||
231 | |||
232 | case sizeof(struct sockaddr_in6): { | ||
233 | const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) &acn[1]; | ||
234 | if (AF_INET6 != s6->sin6_family) | ||
235 | { | ||
236 | GNUNET_break (0); | ||
237 | return GNUNET_SYSERR; | ||
238 | } | ||
239 | } | ||
240 | break; | ||
241 | |||
242 | default: | ||
243 | GNUNET_break (0); | ||
244 | return GNUNET_SYSERR; | ||
245 | } | ||
246 | return GNUNET_OK; | ||
247 | } | ||
248 | |||
249 | |||
250 | /** | ||
251 | * Handle connection reversal request. | ||
252 | * | ||
253 | * @param cls our `struct GNUNET_NAT_Handle` | ||
254 | * @param acn the message | ||
255 | */ | ||
256 | static void | ||
257 | handle_address_change_notification ( | ||
258 | void *cls, | ||
259 | const struct GNUNET_NAT_AddressChangeNotificationMessage *acn) | ||
260 | { | ||
261 | struct GNUNET_NAT_Handle *nh = cls; | ||
262 | size_t alen = ntohs (acn->header.size) - sizeof(*acn); | ||
263 | const struct sockaddr *sa = (const struct sockaddr *) &acn[1]; | ||
264 | enum GNUNET_NAT_AddressClass ac; | ||
265 | struct AddrEntry *ae; | ||
266 | |||
267 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
268 | "Received address change notification\n"); | ||
269 | ac = (enum GNUNET_NAT_AddressClass) ntohl (acn->addr_class); | ||
270 | if (GNUNET_YES == ntohl (acn->add_remove)) | ||
271 | { | ||
272 | ae = GNUNET_malloc (sizeof(*ae) + alen); | ||
273 | ae->ac = ac; | ||
274 | ae->addrlen = alen; | ||
275 | GNUNET_memcpy (&ae[1], sa, alen); | ||
276 | GNUNET_CONTAINER_DLL_insert (nh->ae_head, nh->ae_tail, ae); | ||
277 | nh->address_callback (nh->callback_cls, | ||
278 | &ae->app_ctx, | ||
279 | ntohl (acn->add_remove), | ||
280 | ac, | ||
281 | sa, | ||
282 | alen); | ||
283 | } | ||
284 | else | ||
285 | { | ||
286 | for (ae = nh->ae_head; NULL != ae; ae = ae->next) | ||
287 | if ((ae->addrlen == alen) && (0 == memcmp (&ae[1], sa, alen))) | ||
288 | break; | ||
289 | if (NULL == ae) | ||
290 | { | ||
291 | GNUNET_break (0); | ||
292 | reconnect (nh); | ||
293 | return; | ||
294 | } | ||
295 | GNUNET_CONTAINER_DLL_remove (nh->ae_head, nh->ae_tail, ae); | ||
296 | nh->address_callback (nh->callback_cls, | ||
297 | &ae->app_ctx, | ||
298 | ntohl (acn->add_remove), | ||
299 | ac, | ||
300 | sa, | ||
301 | alen); | ||
302 | GNUNET_free (ae); | ||
303 | } | ||
304 | } | ||
305 | |||
306 | |||
307 | /** | ||
308 | * Handle queue errors by reconnecting to NAT. | ||
309 | * | ||
310 | * @param cls the `struct GNUNET_NAT_Handle *` | ||
311 | * @param error details about the error | ||
312 | */ | ||
313 | static void | ||
314 | mq_error_handler (void *cls, | ||
315 | enum GNUNET_MQ_Error error) | ||
316 | { | ||
317 | struct GNUNET_NAT_Handle *nh = cls; | ||
318 | |||
319 | reconnect (nh); | ||
320 | } | ||
321 | |||
322 | |||
323 | /** | ||
324 | * Task to connect to the NAT service. | ||
325 | * | ||
326 | * @param cls our `struct GNUNET_NAT_Handle *` | ||
327 | */ | ||
328 | static void | ||
329 | do_connect (void *cls) | ||
330 | { | ||
331 | struct GNUNET_NAT_Handle *nh = cls; | ||
332 | struct GNUNET_MQ_MessageHandler handlers[] = { | ||
333 | GNUNET_MQ_hd_var_size ( | ||
334 | connection_reversal_request, | ||
335 | GNUNET_MESSAGE_TYPE_NAT_CONNECTION_REVERSAL_REQUESTED, | ||
336 | struct GNUNET_NAT_ConnectionReversalRequestedMessage, | ||
337 | nh), | ||
338 | GNUNET_MQ_hd_var_size ( | ||
339 | address_change_notification, | ||
340 | GNUNET_MESSAGE_TYPE_NAT_ADDRESS_CHANGE, | ||
341 | struct GNUNET_NAT_AddressChangeNotificationMessage, | ||
342 | nh), | ||
343 | GNUNET_MQ_handler_end () | ||
344 | }; | ||
345 | struct GNUNET_MQ_Envelope *env; | ||
346 | |||
347 | nh->reconnect_task = NULL; | ||
348 | nh->mq = | ||
349 | GNUNET_CLIENT_connect (nh->cfg, | ||
350 | "nat", | ||
351 | handlers, | ||
352 | &mq_error_handler, | ||
353 | nh); | ||
354 | if (NULL == nh->mq) | ||
355 | { | ||
356 | reconnect (nh); | ||
357 | return; | ||
358 | } | ||
359 | env = GNUNET_MQ_msg_copy (nh->reg); | ||
360 | GNUNET_MQ_send (nh->mq, | ||
361 | env); | ||
362 | } | ||
363 | |||
364 | |||
365 | struct GNUNET_NAT_Handle * | ||
366 | GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg, | ||
367 | const char *config_section, | ||
368 | uint8_t proto, | ||
369 | unsigned int num_addrs, | ||
370 | const struct sockaddr **addrs, | ||
371 | const socklen_t *addrlens, | ||
372 | GNUNET_NAT_AddressCallback address_callback, | ||
373 | GNUNET_NAT_ReversalCallback reversal_callback, | ||
374 | void *callback_cls) | ||
375 | { | ||
376 | struct GNUNET_NAT_Handle *nh; | ||
377 | struct GNUNET_NAT_RegisterMessage *rm; | ||
378 | size_t len; | ||
379 | size_t str_len; | ||
380 | char *off; | ||
381 | |||
382 | len = 0; | ||
383 | for (unsigned int i = 0; i < num_addrs; i++) | ||
384 | len += addrlens[i]; | ||
385 | str_len = strlen (config_section) + 1; | ||
386 | len += str_len; | ||
387 | if ( (len > GNUNET_MAX_MESSAGE_SIZE - sizeof(*rm)) || | ||
388 | (num_addrs > UINT16_MAX) || | ||
389 | (str_len > UINT16_MAX) ) | ||
390 | { | ||
391 | GNUNET_break (0); | ||
392 | return NULL; | ||
393 | } | ||
394 | rm = GNUNET_malloc (sizeof(*rm) + len); | ||
395 | rm->header.size = htons (sizeof(*rm) + len); | ||
396 | rm->header.type = htons (GNUNET_MESSAGE_TYPE_NAT_REGISTER); | ||
397 | rm->flags = GNUNET_NAT_RF_NONE; | ||
398 | if (NULL != address_callback) | ||
399 | rm->flags |= GNUNET_NAT_RF_ADDRESSES; | ||
400 | if (NULL != reversal_callback) | ||
401 | rm->flags |= GNUNET_NAT_RF_REVERSAL; | ||
402 | rm->proto = proto; | ||
403 | rm->str_len = htons (str_len); | ||
404 | rm->num_addrs = htons ((uint16_t) num_addrs); | ||
405 | off = (char *) &rm[1]; | ||
406 | for (unsigned int i = 0; i < num_addrs; i++) | ||
407 | { | ||
408 | switch (addrs[i]->sa_family) | ||
409 | { | ||
410 | case AF_INET: | ||
411 | if (sizeof(struct sockaddr_in) != addrlens[i]) | ||
412 | { | ||
413 | GNUNET_break (0); | ||
414 | GNUNET_free (rm); | ||
415 | return NULL; | ||
416 | } | ||
417 | break; | ||
418 | |||
419 | case AF_INET6: | ||
420 | if (sizeof(struct sockaddr_in6) != addrlens[i]) | ||
421 | { | ||
422 | GNUNET_break (0); | ||
423 | GNUNET_free (rm); | ||
424 | return NULL; | ||
425 | } | ||
426 | break; | ||
427 | |||
428 | #if AF_UNIX | ||
429 | case AF_UNIX: | ||
430 | if (sizeof(struct sockaddr_un) != addrlens[i]) | ||
431 | { | ||
432 | GNUNET_break (0); | ||
433 | GNUNET_free (rm); | ||
434 | return NULL; | ||
435 | } | ||
436 | break; | ||
437 | #endif | ||
438 | default: | ||
439 | GNUNET_break (0); | ||
440 | GNUNET_free (rm); | ||
441 | return NULL; | ||
442 | } | ||
443 | GNUNET_memcpy (off, addrs[i], addrlens[i]); | ||
444 | off += addrlens[i]; | ||
445 | } | ||
446 | GNUNET_memcpy (off, config_section, str_len); | ||
447 | |||
448 | nh = GNUNET_new (struct GNUNET_NAT_Handle); | ||
449 | nh->reg = &rm->header; | ||
450 | nh->cfg = cfg; | ||
451 | nh->address_callback = address_callback; | ||
452 | nh->reversal_callback = reversal_callback; | ||
453 | nh->callback_cls = callback_cls; | ||
454 | do_connect (nh); | ||
455 | return nh; | ||
456 | } | ||
457 | |||
458 | |||
459 | /** | ||
460 | * Check if an incoming message is a STUN message. | ||
461 | * | ||
462 | * @param data the packet | ||
463 | * @param len the length of the packet in @a data | ||
464 | * @return #GNUNET_YES if @a data is a STUN packet, | ||
465 | * #GNUNET_NO if the packet is invalid (not a stun packet) | ||
466 | */ | ||
467 | static enum GNUNET_GenericReturnValue | ||
468 | test_stun_packet (const void *data, size_t len) | ||
469 | { | ||
470 | const struct stun_header *hdr; | ||
471 | const struct stun_attr *attr; | ||
472 | uint32_t advertised_message_size; | ||
473 | uint32_t message_magic_cookie; | ||
474 | |||
475 | /* On entry, 'len' is the length of the UDP payload. After the | ||
476 | * initial checks it becomes the size of unprocessed options, | ||
477 | * while 'data' is advanced accordingly. | ||
478 | */ | ||
479 | if (len < sizeof(struct stun_header)) | ||
480 | { | ||
481 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
482 | "STUN packet too short (only %d, wanting at least %d)\n", | ||
483 | (int) len, | ||
484 | (int) sizeof(struct stun_header)); | ||
485 | return GNUNET_NO; | ||
486 | } | ||
487 | hdr = (const struct stun_header *) data; | ||
488 | /* Skip header as it is already in hdr */ | ||
489 | len -= sizeof(struct stun_header); | ||
490 | data += sizeof(struct stun_header); | ||
491 | |||
492 | /* len as advertised in the message */ | ||
493 | advertised_message_size = ntohs (hdr->msglen); | ||
494 | |||
495 | message_magic_cookie = ntohl (hdr->magic); | ||
496 | /* Compare if the cookie match */ | ||
497 | if (STUN_MAGIC_COOKIE != message_magic_cookie) | ||
498 | { | ||
499 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Invalid magic cookie for STUN\n"); | ||
500 | return GNUNET_NO; | ||
501 | } | ||
502 | |||
503 | if (advertised_message_size > len) | ||
504 | { | ||
505 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
506 | "Scrambled STUN packet length (got %d, expecting %d)\n", | ||
507 | advertised_message_size, | ||
508 | (int) len); | ||
509 | return GNUNET_NO; | ||
510 | } | ||
511 | len = advertised_message_size; | ||
512 | while (len > 0) | ||
513 | { | ||
514 | if (len < sizeof(struct stun_attr)) | ||
515 | { | ||
516 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
517 | "Attribute too short in STUN packet (got %d, expecting %d)\n", | ||
518 | (int) len, | ||
519 | (int) sizeof(struct stun_attr)); | ||
520 | return GNUNET_NO; | ||
521 | } | ||
522 | attr = (const struct stun_attr *) data; | ||
523 | |||
524 | /* compute total attribute length */ | ||
525 | advertised_message_size = ntohs (attr->len) + sizeof(struct stun_attr); | ||
526 | |||
527 | /* Check if we still have space in our buffer */ | ||
528 | if (advertised_message_size > len) | ||
529 | { | ||
530 | GNUNET_log ( | ||
531 | GNUNET_ERROR_TYPE_DEBUG, | ||
532 | "Inconsistent Attribute (length %d exceeds remaining msg len %d)\n", | ||
533 | advertised_message_size, | ||
534 | (int) len); | ||
535 | return GNUNET_NO; | ||
536 | } | ||
537 | data += advertised_message_size; | ||
538 | len -= advertised_message_size; | ||
539 | } | ||
540 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
541 | "STUN Packet, msg %04x, length: %d\n", | ||
542 | ntohs (hdr->msgtype), | ||
543 | advertised_message_size); | ||
544 | return GNUNET_OK; | ||
545 | } | ||
546 | |||
547 | |||
548 | /** | ||
549 | * Handle an incoming STUN message. This function is useful as | ||
550 | * some GNUnet service may be listening on a UDP port and might | ||
551 | * thus receive STUN messages while trying to receive other data. | ||
552 | * In this case, this function can be used to process replies | ||
553 | * to STUN requests. | ||
554 | * | ||
555 | * The function does some basic sanity checks on packet size and | ||
556 | * content, try to extract a bit of information. | ||
557 | * | ||
558 | * At the moment this only processes BIND requests, and returns the | ||
559 | * externally visible address of the request to the rest of the | ||
560 | * NAT logic. | ||
561 | * | ||
562 | * @param nh handle to the NAT service | ||
563 | * @param sender_addr address from which we got @a data | ||
564 | * @param sender_addr_len number of bytes in @a sender_addr | ||
565 | * @param data the packet | ||
566 | * @param data_size number of bytes in @a data | ||
567 | * @return #GNUNET_OK on success | ||
568 | * #GNUNET_NO if the packet is not a STUN packet | ||
569 | * #GNUNET_SYSERR on internal error handling the packet | ||
570 | */ | ||
571 | int | ||
572 | GNUNET_NAT_stun_handle_packet (struct GNUNET_NAT_Handle *nh, | ||
573 | const struct sockaddr *sender_addr, | ||
574 | size_t sender_addr_len, | ||
575 | const void *data, | ||
576 | size_t data_size) | ||
577 | { | ||
578 | struct GNUNET_MQ_Envelope *env; | ||
579 | struct GNUNET_NAT_HandleStunMessage *hsn; | ||
580 | char *buf; | ||
581 | |||
582 | if (GNUNET_YES != test_stun_packet (data, data_size)) | ||
583 | return GNUNET_NO; | ||
584 | if (NULL == nh->mq) | ||
585 | return GNUNET_SYSERR; | ||
586 | env = GNUNET_MQ_msg_extra (hsn, | ||
587 | data_size + sender_addr_len, | ||
588 | GNUNET_MESSAGE_TYPE_NAT_HANDLE_STUN); | ||
589 | hsn->sender_addr_size = htons ((uint16_t) sender_addr_len); | ||
590 | hsn->payload_size = htons ((uint16_t) data_size); | ||
591 | buf = (char *) &hsn[1]; | ||
592 | GNUNET_memcpy (buf, sender_addr, sender_addr_len); | ||
593 | buf += sender_addr_len; | ||
594 | GNUNET_memcpy (buf, data, data_size); | ||
595 | GNUNET_MQ_send (nh->mq, env); | ||
596 | return GNUNET_OK; | ||
597 | } | ||
598 | |||
599 | |||
600 | /** | ||
601 | * Test if the given address is (currently) a plausible IP address for | ||
602 | * this peer. Mostly a convenience function so that clients do not | ||
603 | * have to explicitly track all IPs that the #GNUNET_NAT_AddressCallback | ||
604 | * has returned so far. | ||
605 | * | ||
606 | * @param nh the handle returned by register | ||
607 | * @param addr IP address to test (IPv4 or IPv6) | ||
608 | * @param addrlen number of bytes in @a addr | ||
609 | * @return #GNUNET_YES if the address is plausible, | ||
610 | * #GNUNET_NO if the address is not plausible, | ||
611 | * #GNUNET_SYSERR if the address is malformed | ||
612 | */ | ||
613 | int | ||
614 | GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *nh, | ||
615 | const void *addr, | ||
616 | socklen_t addrlen) | ||
617 | { | ||
618 | struct AddrEntry *ae; | ||
619 | |||
620 | if ((addrlen != sizeof(struct sockaddr_in)) && | ||
621 | (addrlen != sizeof(struct sockaddr_in6))) | ||
622 | { | ||
623 | GNUNET_break (0); | ||
624 | return GNUNET_SYSERR; | ||
625 | } | ||
626 | for (ae = nh->ae_head; NULL != ae; ae = ae->next) | ||
627 | if ((addrlen == ae->addrlen) && (0 == memcmp (addr, &ae[1], addrlen))) | ||
628 | return GNUNET_YES; | ||
629 | return GNUNET_NO; | ||
630 | } | ||
631 | |||
632 | |||
633 | /** | ||
634 | * We learned about a peer (possibly behind NAT) so run the | ||
635 | * gnunet-nat-client to send dummy ICMP responses to cause | ||
636 | * that peer to connect to us (connection reversal). | ||
637 | * | ||
638 | * @param nh handle (used for configuration) | ||
639 | * @param local_sa our local address of the peer (IPv4-only) | ||
640 | * @param remote_sa the remote address of the peer (IPv4-only) | ||
641 | * @return #GNUNET_SYSERR on error, | ||
642 | * #GNUNET_NO if connection reversal is unavailable, | ||
643 | * #GNUNET_OK otherwise (presumably in progress) | ||
644 | */ | ||
645 | int | ||
646 | GNUNET_NAT_request_reversal (struct GNUNET_NAT_Handle *nh, | ||
647 | const struct sockaddr_in *local_sa, | ||
648 | const struct sockaddr_in *remote_sa) | ||
649 | { | ||
650 | struct GNUNET_MQ_Envelope *env; | ||
651 | struct GNUNET_NAT_RequestConnectionReversalMessage *req; | ||
652 | char *buf; | ||
653 | |||
654 | if (NULL == nh->mq) | ||
655 | return GNUNET_SYSERR; | ||
656 | GNUNET_break (AF_INET == local_sa->sin_family); | ||
657 | GNUNET_break (AF_INET == remote_sa->sin_family); | ||
658 | env = | ||
659 | GNUNET_MQ_msg_extra (req, | ||
660 | 2 * sizeof(struct sockaddr_in), | ||
661 | GNUNET_MESSAGE_TYPE_NAT_REQUEST_CONNECTION_REVERSAL); | ||
662 | req->local_addr_size = htons (sizeof(struct sockaddr_in)); | ||
663 | req->remote_addr_size = htons (sizeof(struct sockaddr_in)); | ||
664 | buf = (char *) &req[1]; | ||
665 | GNUNET_memcpy (buf, local_sa, sizeof(struct sockaddr_in)); | ||
666 | buf += sizeof(struct sockaddr_in); | ||
667 | GNUNET_memcpy (buf, remote_sa, sizeof(struct sockaddr_in)); | ||
668 | GNUNET_MQ_send (nh->mq, env); | ||
669 | return GNUNET_OK; | ||
670 | } | ||
671 | |||
672 | |||
673 | void | ||
674 | GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *nh) | ||
675 | { | ||
676 | struct AddrEntry *ae; | ||
677 | struct AddrEntry *next; | ||
678 | |||
679 | if (NULL != nh->mq) | ||
680 | { | ||
681 | GNUNET_MQ_destroy (nh->mq); | ||
682 | nh->mq = NULL; | ||
683 | } | ||
684 | if (NULL != nh->reconnect_task) | ||
685 | { | ||
686 | GNUNET_SCHEDULER_cancel (nh->reconnect_task); | ||
687 | nh->reconnect_task = NULL; | ||
688 | } | ||
689 | next = nh->ae_head; | ||
690 | while (NULL != next) | ||
691 | { | ||
692 | ae = next; | ||
693 | next = next->next; | ||
694 | GNUNET_CONTAINER_DLL_remove (nh->ae_head, nh->ae_tail, ae); | ||
695 | GNUNET_free (ae); | ||
696 | } | ||
697 | GNUNET_free (nh->reg); | ||
698 | GNUNET_free (nh); | ||
699 | } | ||
700 | |||
701 | |||
702 | /* end of nat_api.c */ | ||