2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff
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23 * @brief library to access the VPN service and tell it how to redirect traffic
24 * @author Christian Grothoff
27 #include "gnunet_vpn_service.h"
34 struct GNUNET_VPN_Handle
37 * Configuration we use.
39 const struct GNUNET_CONFIGURATION_Handle *cfg;
42 * Connection to VPN service.
44 struct GNUNET_CLIENT_Connection *client;
47 * Active transmission request.
49 struct GNUNET_CLIENT_TransmitHandle *th;
52 * Head of list of active redirection requests.
54 struct GNUNET_VPN_RedirectionRequest *rr_head;
57 * Tail of list of active redirection requests.
59 struct GNUNET_VPN_RedirectionRequest *rr_tail;
62 * Identifier of a reconnect task.
64 GNUNET_SCHEDULER_TaskIdentifier rt;
67 * ID of the last request that was submitted to the service.
69 uint64_t request_id_gen;
75 * Opaque redirection request handle.
77 struct GNUNET_VPN_RedirectionRequest
82 struct GNUNET_VPN_RedirectionRequest *next;
87 struct GNUNET_VPN_RedirectionRequest *prev;
90 * Pointer to the VPN struct.
92 struct GNUNET_VPN_Handle *vh;
95 * Target IP address for the redirection, or NULL for
96 * redirection to service. Allocated after this struct.
101 * Function to call with the designated IP address.
103 GNUNET_VPN_AllocationCallback cb;
111 * For service redirection, identity of the peer offering the service.
113 struct GNUNET_PeerIdentity peer;
116 * For service redirection, service descriptor.
118 GNUNET_HashCode serv;
121 * At what time should the created service mapping expire?
123 struct GNUNET_TIME_Absolute expiration_time;
126 * non-zero if this request has been sent to the service.
131 * Desired address family for the result.
136 * Address family of 'addr'. AF_INET or AF_INET6.
141 * GNUNET_YES if we are to call the callback only after successful
142 * mesh tunnel creation.
147 * For service redirection, IPPROT_UDP or IPPROTO_TCP.
155 * Disconnect from the service (communication error) and reconnect later.
157 * @param vh handle to reconnect.
160 reconnect (struct GNUNET_VPN_Handle *vh);
164 * Function called when we receive a message from the VPN service.
166 * @param cls the 'struct GNUNET_VPN_Handle'
167 * @param msg message received, NULL on timeout or fatal error
170 receive_response (void *cls,
171 const struct GNUNET_MessageHeader* msg)
173 struct GNUNET_VPN_Handle *vh = cls;
174 const struct RedirectToIpResponseMessage *rm;
175 struct GNUNET_VPN_RedirectionRequest *rr;
185 if ( (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_VPN_CLIENT_USE_IP) ||
186 (sizeof (struct RedirectToIpResponseMessage) > (msize = ntohs (msg->size))) )
192 rm = (const struct RedirectToIpResponseMessage *) msg;
193 af = (int) ntohl (rm->result_af);
200 alen = sizeof (struct in_addr);
203 alen = sizeof (struct in6_addr);
210 if ( (msize != alen + sizeof (struct RedirectToIpResponseMessage)) ||
211 (0 == rm->request_id) )
217 for (rr = vh->rr_head; NULL != rr; rr = rr->next)
219 if (rr->request_id == rm->request_id)
221 GNUNET_CONTAINER_DLL_remove (vh->rr_head,
226 (af == AF_UNSPEC) ? NULL : &rm[1]);
231 GNUNET_CLIENT_receive (vh->client,
232 &receive_response, vh,
233 GNUNET_TIME_UNIT_FOREVER_REL);
238 * We're ready to transmit a request to the VPN service. Do it.
240 * @param cls the 'struct GNUNET_VPN_Handle*'
241 * @param size number of bytes available in buf
242 * @param buf where to copy the request
243 * @return number of bytes copied to 'buf'
246 transmit_request (void *cls,
250 struct GNUNET_VPN_Handle *vh = cls;
251 struct GNUNET_VPN_RedirectionRequest *rr;
252 struct RedirectToIpRequestMessage rip;
253 struct RedirectToServiceRequestMessage rs;
259 /* find a pending request */
261 while ( (NULL != rr) &&
262 (0 != rr->request_id) )
272 /* if first request, start receive loop */
273 if (0 == vh->request_id_gen)
274 GNUNET_CLIENT_receive (vh->client,
275 &receive_response, vh,
276 GNUNET_TIME_UNIT_FOREVER_REL);
277 if (NULL == rr->addr)
279 ret = sizeof (struct RedirectToServiceRequestMessage);
280 GNUNET_assert (ret <= size);
281 rs.header.size = htons ((uint16_t) ret);
282 rs.header.type = htons (GNUNET_MESSAGE_TYPE_VPN_CLIENT_REDIRECT_TO_SERVICE);
283 rs.nac = htonl (rr->nac);
284 rs.expiration_time = GNUNET_TIME_absolute_hton (rr->expiration_time);
285 rs.protocol = htonl (rr->protocol);
286 rs.result_af = htonl (rr->result_af);
287 rs.target = rr->peer;
288 rs.service_descriptor = rr->serv;
289 rs.request_id = rr->request_id = ++vh->request_id_gen;
290 memcpy (buf, &rs, sizeof (struct RedirectToServiceRequestMessage));
297 alen = sizeof (struct in_addr);
300 alen = sizeof (struct in6_addr);
306 ret = alen + sizeof (struct RedirectToIpRequestMessage);
307 GNUNET_assert (ret <= size);
308 rip.header.size = htons ((uint16_t) ret);
309 rip.header.type = htons (GNUNET_MESSAGE_TYPE_VPN_CLIENT_REDIRECT_TO_IP);
310 rip.nac = htonl (rr->nac);
311 rip.expiration_time = GNUNET_TIME_absolute_hton (rr->expiration_time);
312 rip.result_af = htonl (rr->result_af);
313 rip.addr_af = htonl (rr->addr_af);
314 rip.request_id = rr->request_id = ++vh->request_id_gen;
316 memcpy (cbuf, &rip, sizeof (struct RedirectToIpRequestMessage));
317 memcpy (&cbuf[sizeof (struct RedirectToIpRequestMessage)], rr->addr, alen);
319 /* test if there are more pending requests */
320 while ( (NULL != rr) &&
321 (0 != rr->request_id) )
324 vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
325 sizeof (struct RedirectToServiceRequestMessage),
326 GNUNET_TIME_UNIT_FOREVER_REL,
335 * Add a request to our request queue and transmit it.
337 * @param rr request to queue and transmit.
340 queue_request (struct GNUNET_VPN_RedirectionRequest *rr)
342 struct GNUNET_VPN_Handle *vh;
345 GNUNET_CONTAINER_DLL_insert_tail (vh->rr_head,
348 if ( (NULL == vh->th) &&
349 (NULL != vh->client) )
350 vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
351 sizeof (struct RedirectToServiceRequestMessage),
352 GNUNET_TIME_UNIT_FOREVER_REL,
360 * Connect to the VPN service and start again to transmit our requests.
362 * @param cls the 'struct GNUNET_VPN_Handle *'
363 * @param tc scheduler context
366 connect_task (void *cls,
367 const struct GNUNET_SCHEDULER_TaskContext *tc)
369 struct GNUNET_VPN_Handle *vh = cls;
371 vh->rt = GNUNET_SCHEDULER_NO_TASK;
372 vh->client = GNUNET_CLIENT_connect ("vpn", vh->cfg);
373 GNUNET_assert (NULL != vh->client);
374 GNUNET_assert (NULL == vh->th);
375 if (NULL != vh->rr_head)
376 vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
377 sizeof (struct RedirectToServiceRequestMessage),
378 GNUNET_TIME_UNIT_FOREVER_REL,
386 * Disconnect from the service (communication error) and reconnect later.
388 * @param vh handle to reconnect.
391 reconnect (struct GNUNET_VPN_Handle *vh)
393 struct GNUNET_VPN_RedirectionRequest *rr;
397 GNUNET_CLIENT_notify_transmit_ready_cancel (vh->th);
400 GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
402 vh->request_id_gen = 0;
403 for (rr = vh->rr_head; NULL != rr; rr = rr->next)
405 vh->rt = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
412 * Cancel redirection request with the service.
414 * @param rr request to cancel
417 GNUNET_VPN_cancel_request (struct GNUNET_VPN_RedirectionRequest *rr)
419 struct GNUNET_VPN_Handle *vh;
422 GNUNET_CONTAINER_DLL_remove (vh->rr_head,
430 * Tell the VPN that a forwarding to a particular peer offering a
431 * particular service is requested. The VPN is to reserve a
432 * particular IP for the redirection and return it. The VPN will
433 * begin the redirection as soon as possible and maintain it as long
434 * as it is actively used and keeping it is feasible. Given resource
435 * limitations, the longest inactive mappings will be destroyed.
437 * @param vh VPN handle
438 * @param result_af desired address family for the returned allocation
439 * can also be AF_UNSPEC
440 * @param protocol protocol, IPPROTO_UDP or IPPROTO_TCP
441 * @param peer target peer for the redirection
442 * @param serv service descriptor to give to the peer
443 * @param nac GNUNET_YES to notify via callback only after completion of
444 * the MESH-level connection,
445 * GNUNET_NO to notify as soon as the IP has been reserved
446 * @param expiration_time at what time should the redirection expire?
447 * (this should not impact connections that are active at that time)
448 * @param cb function to call with the IP
449 * @param cb_cls closure for cb
450 * @return handle to cancel the request (means the callback won't be
451 * invoked anymore; the mapping may or may not be established
454 struct GNUNET_VPN_RedirectionRequest *
455 GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *vh,
458 const struct GNUNET_PeerIdentity *peer,
459 const GNUNET_HashCode *serv,
461 struct GNUNET_TIME_Absolute expiration_time,
462 GNUNET_VPN_AllocationCallback cb,
465 struct GNUNET_VPN_RedirectionRequest *rr;
467 rr = GNUNET_malloc (sizeof (struct GNUNET_VPN_RedirectionRequest));
473 rr->expiration_time = expiration_time;
474 rr->result_af = result_af;
476 rr->protocol = protocol;
483 * Tell the VPN that forwarding to the Internet via some exit node is
484 * requested. Note that both UDP and TCP traffic will be forwarded,
485 * but possibly to different exit nodes. The VPN is to reserve a
486 * particular IP for the redirection and return it. The VPN will
487 * begin the redirection as soon as possible and maintain it as long
488 * as it is actively used and keeping it is feasible. Given resource
489 * limitations, the longest inactive mappings will be destroyed.
491 * @param vh VPN handle
492 * @param result_af desired address family for the returned allocation
493 * @param addr_af address family for 'addr', AF_INET or AF_INET6
494 * @param addr destination IP address on the Internet; destination
495 * port is to be taken from the VPN packet itself
496 * @param nac GNUNET_YES to notify via callback only after completion of
497 * the MESH-level connection,
498 * GNUNET_NO to notify as soon as the IP has been reserved
499 * @param expiration_time at what time should the redirection expire?
500 * (this should not impact connections that are active at that time)
501 * @param cb function to call with the IP
502 * @param cb_cls closure for cb
503 * @return handle to cancel the request (means the callback won't be
504 * invoked anymore; the mapping may or may not be established
507 struct GNUNET_VPN_RedirectionRequest *
508 GNUNET_VPN_redirect_to_ip (struct GNUNET_VPN_Handle *vh,
513 struct GNUNET_TIME_Absolute expiration_time,
514 GNUNET_VPN_AllocationCallback cb,
517 struct GNUNET_VPN_RedirectionRequest *rr;
523 alen = sizeof (struct in_addr);
526 alen = sizeof (struct in6_addr);
532 rr = GNUNET_malloc (sizeof (struct GNUNET_VPN_RedirectionRequest) + alen);
537 rr->expiration_time = expiration_time;
538 rr->result_af = result_af;
539 rr->addr_af = addr_af;
541 memcpy (&rr[1], addr, alen);
548 * Connect to the VPN service
550 * @param cfg configuration to use
553 struct GNUNET_VPN_Handle *
554 GNUNET_VPN_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
556 struct GNUNET_VPN_Handle *vh;
558 vh = GNUNET_malloc (sizeof (struct GNUNET_VPN_Handle));
560 vh->client = GNUNET_CLIENT_connect ("vpn", cfg);
561 if (NULL == vh->client)
571 * Disconnect from the VPN service.
573 * @param vh VPN handle
576 GNUNET_VPN_disconnect (struct GNUNET_VPN_Handle *vh)
578 GNUNET_assert (NULL == vh->rr_head);
581 GNUNET_CLIENT_notify_transmit_ready_cancel (vh->th);
584 if (NULL != vh->client)
586 GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
589 if (GNUNET_SCHEDULER_NO_TASK != vh->rt)
591 GNUNET_SCHEDULER_cancel (vh->rt);
592 vh->rt = GNUNET_SCHEDULER_NO_TASK;
597 /* end of vpn_api.c */