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) )
267 /* if first request, start receive loop */
268 if (0 == vh->request_id_gen)
269 GNUNET_CLIENT_receive (vh->client,
270 &receive_response, vh,
271 GNUNET_TIME_UNIT_FOREVER_REL);
272 if (NULL == rr->addr)
274 ret = sizeof (struct RedirectToServiceRequestMessage);
275 rs.header.size = htons ((uint16_t) ret);
276 rs.header.type = htons (GNUNET_MESSAGE_TYPE_VPN_CLIENT_REDIRECT_TO_SERVICE);
277 rs.nac = htonl (rr->nac);
278 rs.expiration_time = GNUNET_TIME_absolute_hton (rr->expiration_time);
279 rs.protocol = htonl (rr->protocol);
280 rs.result_af = htonl (rr->result_af);
281 rs.target = rr->peer;
282 rs.service_descriptor = rr->serv;
283 rs.request_id = rr->request_id = ++vh->request_id_gen;
284 memcpy (buf, &rs, sizeof (struct RedirectToServiceRequestMessage));
291 alen = sizeof (struct in_addr);
294 alen = sizeof (struct in6_addr);
300 ret = alen + sizeof (struct RedirectToIpRequestMessage);
301 rip.header.size = htons ((uint16_t) ret);
302 rip.header.type = htons (GNUNET_MESSAGE_TYPE_VPN_CLIENT_REDIRECT_TO_IP);
303 rip.nac = htonl (rr->nac);
304 rip.expiration_time = GNUNET_TIME_absolute_hton (rr->expiration_time);
305 rip.result_af = htonl (rr->result_af);
306 rip.addr_af = htonl (rr->addr_af);
307 rip.request_id = rr->request_id = ++vh->request_id_gen;
309 memcpy (cbuf, &rip, sizeof (struct RedirectToIpRequestMessage));
310 memcpy (&cbuf[sizeof (struct RedirectToIpRequestMessage)], rr->addr, alen);
312 /* test if there are more pending requests */
313 while ( (NULL != rr) &&
314 (0 != rr->request_id) )
317 vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
318 sizeof (struct RedirectToServiceRequestMessage),
319 GNUNET_TIME_UNIT_FOREVER_REL,
328 * Add a request to our request queue and transmit it.
330 * @param rr request to queue and transmit.
333 queue_request (struct GNUNET_VPN_RedirectionRequest *rr)
335 struct GNUNET_VPN_Handle *vh;
338 GNUNET_CONTAINER_DLL_insert_tail (vh->rr_head,
341 if ( (NULL == vh->th) &&
342 (NULL != vh->client) )
343 vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
344 sizeof (struct RedirectToServiceRequestMessage),
345 GNUNET_TIME_UNIT_FOREVER_REL,
353 * Connect to the VPN service and start again to transmit our requests.
355 * @param cls the 'struct GNUNET_VPN_Handle *'
356 * @param tc scheduler context
359 connect_task (void *cls,
360 const struct GNUNET_SCHEDULER_TaskContext *tc)
362 struct GNUNET_VPN_Handle *vh = cls;
364 vh->client = GNUNET_CLIENT_connect ("vpn", vh->cfg);
365 GNUNET_assert (NULL != vh->client);
366 GNUNET_assert (NULL != vh->th);
367 if (NULL != vh->rr_head)
368 vh->th = GNUNET_CLIENT_notify_transmit_ready (vh->client,
369 sizeof (struct RedirectToServiceRequestMessage),
370 GNUNET_TIME_UNIT_FOREVER_REL,
378 * Disconnect from the service (communication error) and reconnect later.
380 * @param vh handle to reconnect.
383 reconnect (struct GNUNET_VPN_Handle *vh)
385 struct GNUNET_VPN_RedirectionRequest *rr;
389 GNUNET_CLIENT_notify_transmit_ready_cancel (vh->th);
392 GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
394 vh->request_id_gen = 0;
395 for (rr = vh->rr_head; NULL != rr; rr = rr->next)
397 vh->rt = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
404 * Cancel redirection request with the service.
406 * @param rr request to cancel
409 GNUNET_VPN_cancel_request (struct GNUNET_VPN_RedirectionRequest *rr)
411 struct GNUNET_VPN_Handle *vh;
414 GNUNET_CONTAINER_DLL_remove (vh->rr_head,
422 * Tell the VPN that a forwarding to a particular peer offering a
423 * particular service is requested. The VPN is to reserve a
424 * particular IP for the redirection and return it. The VPN will
425 * begin the redirection as soon as possible and maintain it as long
426 * as it is actively used and keeping it is feasible. Given resource
427 * limitations, the longest inactive mappings will be destroyed.
429 * @param vh VPN handle
430 * @param result_af desired address family for the returned allocation
431 * can also be AF_UNSPEC
432 * @param protocol protocol, IPPROTO_UDP or IPPROTO_TCP
433 * @param peer target peer for the redirection
434 * @param serv service descriptor to give to the peer
435 * @param nac GNUNET_YES to notify via callback only after completion of
436 * the MESH-level connection,
437 * GNUNET_NO to notify as soon as the IP has been reserved
438 * @param expiration_time at what time should the redirection expire?
439 * (this should not impact connections that are active at that time)
440 * @param cb function to call with the IP
441 * @param cb_cls closure for cb
442 * @return handle to cancel the request (means the callback won't be
443 * invoked anymore; the mapping may or may not be established
446 struct GNUNET_VPN_RedirectionRequest *
447 GNUNET_VPN_redirect_to_peer (struct GNUNET_VPN_Handle *vh,
450 const struct GNUNET_PeerIdentity *peer,
451 const GNUNET_HashCode *serv,
453 struct GNUNET_TIME_Absolute expiration_time,
454 GNUNET_VPN_AllocationCallback cb,
457 struct GNUNET_VPN_RedirectionRequest *rr;
459 rr = GNUNET_malloc (sizeof (struct GNUNET_VPN_RedirectionRequest));
465 rr->expiration_time = expiration_time;
466 rr->result_af = result_af;
468 rr->protocol = protocol;
475 * Tell the VPN that forwarding to the Internet via some exit node is
476 * requested. Note that both UDP and TCP traffic will be forwarded,
477 * but possibly to different exit nodes. The VPN is to reserve a
478 * particular IP for the redirection and return it. The VPN will
479 * begin the redirection as soon as possible and maintain it as long
480 * as it is actively used and keeping it is feasible. Given resource
481 * limitations, the longest inactive mappings will be destroyed.
483 * @param vh VPN handle
484 * @param result_af desired address family for the returned allocation
485 * @param addr_af address family for 'addr', AF_INET or AF_INET6
486 * @param addr destination IP address on the Internet; destination
487 * port is to be taken from the VPN packet itself
488 * @param nac GNUNET_YES to notify via callback only after completion of
489 * the MESH-level connection,
490 * GNUNET_NO to notify as soon as the IP has been reserved
491 * @param expiration_time at what time should the redirection expire?
492 * (this should not impact connections that are active at that time)
493 * @param cb function to call with the IP
494 * @param cb_cls closure for cb
495 * @return handle to cancel the request (means the callback won't be
496 * invoked anymore; the mapping may or may not be established
499 struct GNUNET_VPN_RedirectionRequest *
500 GNUNET_VPN_redirect_to_ip (struct GNUNET_VPN_Handle *vh,
505 struct GNUNET_TIME_Absolute expiration_time,
506 GNUNET_VPN_AllocationCallback cb,
509 struct GNUNET_VPN_RedirectionRequest *rr;
515 alen = sizeof (struct in_addr);
518 alen = sizeof (struct in6_addr);
524 rr = GNUNET_malloc (sizeof (struct GNUNET_VPN_RedirectionRequest) + alen);
529 rr->expiration_time = expiration_time;
530 rr->result_af = result_af;
531 rr->addr_af = addr_af;
533 memcpy (&rr[1], addr, alen);
540 * Connect to the VPN service
542 * @param cfg configuration to use
545 struct GNUNET_VPN_Handle *
546 GNUNET_VPN_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
548 struct GNUNET_VPN_Handle *vh;
550 vh = GNUNET_malloc (sizeof (struct GNUNET_VPN_Handle));
552 vh->client = GNUNET_CLIENT_connect ("vpn", cfg);
553 if (NULL == vh->client)
563 * Disconnect from the VPN service.
565 * @param vh VPN handle
568 GNUNET_VPN_disconnect (struct GNUNET_VPN_Handle *vh)
570 GNUNET_assert (NULL == vh->rr_head);
573 GNUNET_CLIENT_notify_transmit_ready_cancel (vh->th);
576 if (NULL != vh->client)
578 GNUNET_CLIENT_disconnect (vh->client, GNUNET_NO);
581 if (GNUNET_SCHEDULER_NO_TASK != vh->rt)
583 GNUNET_SCHEDULER_cancel (vh->rt);
584 vh->rt = GNUNET_SCHEDULER_NO_TASK;
589 /* end of vpn_api.c */