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22 * @file cadet/gnunet-service-cadet_core.c
23 * @brief cadet service; interaction with CORE service
24 * @author Bartlomiej Polot
25 * @author Christian Grothoff
27 * All functions in this file should use the prefix GCO (Gnunet Cadet cOre (bottom))
30 * - Optimization: given BROKEN messages, destroy paths (?)
33 #include "gnunet-service-cadet-new_core.h"
34 #include "gnunet-service-cadet-new_paths.h"
35 #include "gnunet-service-cadet-new_peer.h"
36 #include "gnunet-service-cadet-new_connection.h"
37 #include "gnunet-service-cadet-new_tunnels.h"
38 #include "gnunet_core_service.h"
39 #include "cadet_protocol.h"
42 #define LOG(level, ...) GNUNET_log_from(level,"cadet-cor",__VA_ARGS__)
46 * Number of messages we are willing to buffer per route.
48 #define ROUTE_BUFFER_SIZE 8
52 * Information we keep per direction for a route.
59 struct CadetPeer *hop;
62 * Route this direction is part of.
64 struct CadetRoute *my_route;
67 * Message queue manager for @e hop.
69 struct GCP_MessageQueueManager *mqm;
72 * Cyclic message buffer to @e hop.
74 struct GNUNET_MQ_Envelope *out_buffer[ROUTE_BUFFER_SIZE];
77 * Next write offset to use to append messages to @e out_buffer.
79 unsigned int out_wpos;
82 * Next read offset to use to retrieve messages from @e out_buffer.
84 unsigned int out_rpos;
87 * Is @e mqm currently ready for transmission?
95 * Description of a segment of a `struct CadetConnection` at the
96 * intermediate peers. Routes are basically entries in a peer's
97 * routing table for forwarding traffic. At both endpoints, the
98 * routes are terminated by a `struct CadetConnection`, which knows
99 * the complete `struct CadetPath` that is formed by the individual
106 * Information about the next hop on this route.
108 struct RouteDirection next;
111 * Information about the previous hop on this route.
113 struct RouteDirection prev;
116 * Unique identifier for the connection that uses this route.
118 struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
121 * When was this route last in use?
123 struct GNUNET_TIME_Absolute last_use;
129 * Handle to the CORE service.
131 static struct GNUNET_CORE_Handle *core;
134 * Routes on which this peer is an intermediate.
136 static struct GNUNET_CONTAINER_MultiShortmap *routes;
140 * Get the route corresponding to a hash.
142 * @param cid hash generated from the connection identifier
144 static struct CadetRoute *
145 get_route (const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid)
147 return GNUNET_CONTAINER_multishortmap_get (routes,
148 &cid->connection_of_tunnel);
153 * We message @a msg from @a prev. Find its route by @a cid and
154 * forward to the next hop. Drop and signal broken route if we do not
157 * @param prev previous hop (sender)
158 * @param cid connection identifier, tells us which route to use
159 * @param msg the message to forward
162 route_message (struct CadetPeer *prev,
163 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
164 const struct GNUNET_MessageHeader *msg)
166 struct CadetRoute *route;
167 struct RouteDirection *dir;
168 struct GNUNET_MQ_Envelope *env;
170 route = get_route (cid);
173 struct GNUNET_MQ_Envelope *env;
174 struct GNUNET_CADET_ConnectionBrokenMessage *bm;
176 LOG (GNUNET_ERROR_TYPE_DEBUG,
177 "Failed to route message of type %u from %s on connection %s: no route\n",
180 GNUNET_sh2s (&cid->connection_of_tunnel));
181 env = GNUNET_MQ_msg (bm,
182 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
184 bm->peer1 = my_full_id;
189 dir = (prev == route->prev.hop) ? &route->next : &route->prev;
190 if (GNUNET_YES == dir->is_ready)
192 LOG (GNUNET_ERROR_TYPE_DEBUG,
193 "Routing message of type %u from %s to %s on connection %s\n",
196 GNUNET_i2s (GCP_get_id (dir->hop)),
197 GNUNET_sh2s (&cid->connection_of_tunnel));
198 dir->is_ready = GNUNET_NO;
200 GNUNET_MQ_msg_copy (msg));
203 env = dir->out_buffer[dir->out_wpos];
206 /* Queue full, drop earliest message in queue */
207 LOG (GNUNET_ERROR_TYPE_DEBUG,
208 "Queue full due to new message of type %u from %s to %s on connection %s, dropping old message\n",
211 GNUNET_i2s (GCP_get_id (dir->hop)),
212 GNUNET_sh2s (&cid->connection_of_tunnel));
213 GNUNET_assert (dir->out_rpos == dir->out_wpos);
214 GNUNET_MQ_discard (env);
216 if (ROUTE_BUFFER_SIZE == dir->out_rpos)
219 LOG (GNUNET_ERROR_TYPE_DEBUG,
220 "Queueing new message of type %u from %s to %s on connection %s\n",
223 GNUNET_i2s (GCP_get_id (dir->hop)),
224 GNUNET_sh2s (&cid->connection_of_tunnel));
225 env = GNUNET_MQ_msg_copy (msg);
226 dir->out_buffer[dir->out_wpos] = env;
228 if (ROUTE_BUFFER_SIZE == dir->out_wpos)
234 * Check if the create_connection message has the appropriate size.
236 * @param cls Closure (unused).
237 * @param msg Message to check.
239 * @return #GNUNET_YES if size is correct, #GNUNET_NO otherwise.
242 check_connection_create (void *cls,
243 const struct GNUNET_CADET_ConnectionCreateMessage *msg)
245 uint16_t size = ntohs (msg->header.size) - sizeof (*msg);
247 if (0 != (size % sizeof (struct GNUNET_PeerIdentity)))
257 * Free internal data of a route direction.
259 * @param dir direction to destroy (do NOT free memory of 'dir' itself)
262 destroy_direction (struct RouteDirection *dir)
264 for (unsigned int i=0;i<ROUTE_BUFFER_SIZE;i++)
265 if (NULL != dir->out_buffer[i])
267 GNUNET_MQ_discard (dir->out_buffer[i]);
268 dir->out_buffer[i] = NULL;
270 if (NULL != dir->mqm)
272 GCP_request_mq_cancel (dir->mqm,
280 * Destroy our state for @a route.
282 * @param route route to destroy
285 destroy_route (struct CadetRoute *route)
287 LOG (GNUNET_ERROR_TYPE_DEBUG,
288 "Destroying route from %s to %s of connection %s\n",
289 GNUNET_i2s (GCP_get_id (route->prev.hop)),
290 GNUNET_i2s2 (GCP_get_id (route->next.hop)),
291 GNUNET_sh2s (&route->cid.connection_of_tunnel));
292 destroy_direction (&route->prev);
293 destroy_direction (&route->next);
299 * Send message that a route is broken between @a peer1 and @a peer2.
301 * @param target where to send the message
302 * @param cid connection identifier to use
303 * @param peer1 one of the peers where a link is broken
304 * @param peer2 another one of the peers where a link is broken
307 send_broken (struct RouteDirection *target,
308 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
309 const struct GNUNET_PeerIdentity *peer1,
310 const struct GNUNET_PeerIdentity *peer2)
312 struct GNUNET_MQ_Envelope *env;
313 struct GNUNET_CADET_ConnectionBrokenMessage *bm;
315 if (NULL == target->mqm)
316 return; /* Can't send notification, connection is down! */
317 LOG (GNUNET_ERROR_TYPE_DEBUG,
318 "Notifying %s about BROKEN route at %s-%s of connection %s\n",
319 GCP_2s (target->hop),
322 GNUNET_sh2s (&cid->connection_of_tunnel));
324 env = GNUNET_MQ_msg (bm,
325 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
332 GCP_request_mq_cancel (target->mqm,
339 * Function called when the message queue to the previous hop
340 * becomes available/unavailable. We expect this function to
341 * be called immediately when we register, and then again
342 * later if the connection ever goes down.
344 * @param cls the `struct RouteDirection`
345 * @param available #GNUNET_YES if sending is now possible,
346 * #GNUNET_NO if sending is no longer possible
347 * #GNUNET_SYSERR if sending is no longer possible
348 * and the last envelope was discarded
351 dir_ready_cb (void *cls,
354 struct RouteDirection *dir = cls;
355 struct CadetRoute *route = dir->my_route;
356 struct RouteDirection *odir;
358 if (GNUNET_YES == ready)
360 struct GNUNET_MQ_Envelope *env;
362 dir->is_ready = GNUNET_YES;
363 if (NULL != (env = dir->out_buffer[dir->out_rpos]))
365 dir->out_buffer[dir->out_rpos] = NULL;
367 if (ROUTE_BUFFER_SIZE == dir->out_rpos)
369 dir->is_ready = GNUNET_NO;
375 odir = (dir == &route->next) ? &route->prev : &route->next;
376 send_broken (&route->next,
378 GCP_get_id (odir->hop),
380 destroy_route (route);
385 * Initialize one of the directions of a route.
387 * @param route route the direction belongs to
388 * @param dir direction to initialize
389 * @param hop next hop on in the @a dir
392 dir_init (struct RouteDirection *dir,
393 struct CadetRoute *route,
394 struct CadetPeer *hop)
397 dir->my_route = route;
398 dir->mqm = GCP_request_mq (hop,
401 GNUNET_assert (GNUNET_YES == dir->is_ready);
406 * Handle for #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE
408 * @param cls Closure (CadetPeer for neighbor that sent the message).
409 * @param msg Message itself.
412 handle_connection_create (void *cls,
413 const struct GNUNET_CADET_ConnectionCreateMessage *msg)
415 struct CadetPeer *sender = cls;
416 struct CadetPeer *next;
417 const struct GNUNET_PeerIdentity *pids = (const struct GNUNET_PeerIdentity *) &msg[1];
418 struct CadetRoute *route;
419 uint16_t size = ntohs (msg->header.size) - sizeof (*msg);
420 unsigned int path_length;
423 path_length = size / sizeof (struct GNUNET_PeerIdentity);
424 /* Initiator is at offset 0. */
425 for (off=1;off<path_length;off++)
426 if (0 == memcmp (&my_full_id,
428 sizeof (struct GNUNET_PeerIdentity)))
430 if (off == path_length)
432 /* We are not on the path, bogus request */
436 /* Check previous hop */
437 if (sender != GCP_get (&pids[off - 1],
440 /* sender is not on the path, not allowed */
445 get_route (&msg->cid))
447 /* Duplicate CREATE, pass it on, previous one might have been lost! */
448 LOG (GNUNET_ERROR_TYPE_DEBUG,
449 "Passing on duplicate CADET_CONNECTION_CREATE message on connection %s\n",
450 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
451 route_message (sender,
456 if (off == path_length - 1)
458 /* We are the destination, create connection */
459 struct CadetConnection *cc;
460 struct CadetPeerPath *path;
461 struct CadetPeer *origin;
463 cc = GNUNET_CONTAINER_multishortmap_get (connections,
464 &msg->cid.connection_of_tunnel);
467 LOG (GNUNET_ERROR_TYPE_DEBUG,
468 "Received duplicate CADET_CONNECTION_CREATE message on connection %s\n",
469 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
470 GCC_handle_duplicate_create (cc);
474 origin = GCP_get (&pids[0],
476 LOG (GNUNET_ERROR_TYPE_DEBUG,
477 "Received CADET_CONNECTION_CREATE message from %s for connection %s, building inverse path\n",
479 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
480 path = GCPP_get_path_from_route (path_length - 1,
483 GCT_add_inbound_connection (GCP_get_tunnel (origin,
488 /* Send back BROKEN: duplicate connection on the same path,
489 we will use the other one. */
490 struct GNUNET_MQ_Envelope *env;
491 struct GNUNET_CADET_ConnectionBrokenMessage *bm;
493 LOG (GNUNET_ERROR_TYPE_DEBUG,
494 "Received CADET_CONNECTION_CREATE from %s for %s, but %s already has a connection. Sending BROKEN\n",
496 GNUNET_sh2s (&msg->cid.connection_of_tunnel),
498 env = GNUNET_MQ_msg (bm,
499 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
501 bm->peer1 = my_full_id;
502 GCP_send_ooo (sender,
508 /* We are merely a hop on the way, check if we can support the route */
509 next = GCP_get (&pids[off + 1],
511 if ( (NULL == next) ||
512 (GNUNET_NO == GCP_has_core_connection (next)) )
514 /* unworkable, send back BROKEN notification */
515 struct GNUNET_MQ_Envelope *env;
516 struct GNUNET_CADET_ConnectionBrokenMessage *bm;
518 LOG (GNUNET_ERROR_TYPE_DEBUG,
519 "Received CADET_CONNECTION_CREATE from %s for %s. Next hop %s:%u is down. Sending BROKEN\n",
521 GNUNET_sh2s (&msg->cid.connection_of_tunnel),
522 GNUNET_i2s (&pids[off + 1]),
524 env = GNUNET_MQ_msg (bm,
525 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN);
527 bm->peer1 = pids[off + 1];
528 bm->peer2 = my_full_id;
529 GCP_send_ooo (sender,
534 /* Workable route, create routing entry */
535 LOG (GNUNET_ERROR_TYPE_DEBUG,
536 "Received CADET_CONNECTION_CREATE from %s for %s. Next hop %s:%u is up. Creating route\n",
538 GNUNET_sh2s (&msg->cid.connection_of_tunnel),
539 GNUNET_i2s (&pids[off + 1]),
541 route = GNUNET_new (struct CadetRoute);
542 route->cid = msg->cid;
543 dir_init (&route->prev,
546 dir_init (&route->next,
549 GNUNET_assert (GNUNET_OK ==
550 GNUNET_CONTAINER_multishortmap_put (routes,
551 &route->cid.connection_of_tunnel,
553 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
558 * Handle for #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK
560 * @param cls Closure (CadetPeer for neighbor that sent the message).
561 * @param msg Message itself.
564 handle_connection_create_ack (void *cls,
565 const struct GNUNET_CADET_ConnectionCreateAckMessage *msg)
567 struct CadetPeer *peer = cls;
568 struct CadetConnection *cc;
570 /* First, check if ACK belongs to a connection that ends here. */
571 cc = GNUNET_CONTAINER_multishortmap_get (connections,
572 &msg->cid.connection_of_tunnel);
575 /* verify ACK came from the right direction */
576 struct CadetPeerPath *path = GCC_get_path (cc);
579 GCPP_get_peer_at_offset (path,
582 /* received ACK from unexpected direction, ignore! */
586 LOG (GNUNET_ERROR_TYPE_DEBUG,
587 "Received CONNECTION_CREATE_ACK for connection %s.\n",
588 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
589 GCC_handle_connection_create_ack (cc);
593 /* We're just an intermediary peer, route the message along its path */
601 * Handle for #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN
603 * @param cls Closure (CadetPeer for neighbor that sent the message).
604 * @param msg Message itself.
605 * @deprecated duplicate logic with #handle_destroy(); dedup!
608 handle_connection_broken (void *cls,
609 const struct GNUNET_CADET_ConnectionBrokenMessage *msg)
611 struct CadetPeer *peer = cls;
612 struct CadetConnection *cc;
613 struct CadetRoute *route;
615 /* First, check if message belongs to a connection that ends here. */
616 cc = GNUNET_CONTAINER_multishortmap_get (connections,
617 &msg->cid.connection_of_tunnel);
620 /* verify message came from the right direction */
621 struct CadetPeerPath *path = GCC_get_path (cc);
624 GCPP_get_peer_at_offset (path,
627 /* received message from unexpected direction, ignore! */
631 LOG (GNUNET_ERROR_TYPE_DEBUG,
632 "Received CONNECTION_BROKEN for connection %s. Destroying it.\n",
633 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
634 GCC_destroy_without_core (cc);
636 /* FIXME: also destroy the path up to the specified link! */
640 /* We're just an intermediary peer, route the message along its path */
641 route = get_route (&msg->cid);
645 destroy_route (route);
646 /* FIXME: also destroy paths we MAY have up to the specified link! */
651 * Handle for #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY
653 * @param cls Closure (CadetPeer for neighbor that sent the message).
654 * @param msg Message itself.
657 handle_connection_destroy (void *cls,
658 const struct GNUNET_CADET_ConnectionDestroyMessage *msg)
660 struct CadetPeer *peer = cls;
661 struct CadetConnection *cc;
662 struct CadetRoute *route;
664 /* First, check if message belongs to a connection that ends here. */
665 cc = GNUNET_CONTAINER_multishortmap_get (connections,
666 &msg->cid.connection_of_tunnel);
669 /* verify message came from the right direction */
670 struct CadetPeerPath *path = GCC_get_path (cc);
673 GCPP_get_peer_at_offset (path,
676 /* received message from unexpected direction, ignore! */
680 LOG (GNUNET_ERROR_TYPE_DEBUG,
681 "Received CONNECTION_DESTROY for connection %s. Destroying connection.\n",
682 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
684 GCC_destroy_without_core (cc);
688 /* We're just an intermediary peer, route the message along its path */
689 LOG (GNUNET_ERROR_TYPE_DEBUG,
690 "Received CONNECTION_DESTROY for connection %s. Destroying route.\n",
691 GNUNET_sh2s (&msg->cid.connection_of_tunnel));
692 route = get_route (&msg->cid);
696 destroy_route (route);
701 * Handle for #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX
703 * @param cls Closure (CadetPeer for neighbor that sent the message).
704 * @param msg Message itself.
707 handle_tunnel_kx (void *cls,
708 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg)
710 struct CadetPeer *peer = cls;
711 struct CadetConnection *cc;
713 /* First, check if message belongs to a connection that ends here. */
714 cc = GNUNET_CONTAINER_multishortmap_get (connections,
715 &msg->cid.connection_of_tunnel);
718 /* verify message came from the right direction */
719 struct CadetPeerPath *path = GCC_get_path (cc);
722 GCPP_get_peer_at_offset (path,
725 /* received message from unexpected direction, ignore! */
734 /* We're just an intermediary peer, route the message along its path */
742 * Check if the encrypted message has the appropriate size.
744 * @param cls Closure (unused).
745 * @param msg Message to check.
747 * @return #GNUNET_YES if size is correct, #GNUNET_NO otherwise.
750 check_tunnel_encrypted (void *cls,
751 const struct GNUNET_CADET_TunnelEncryptedMessage *msg)
758 * Handle for #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED.
760 * @param cls Closure (CadetPeer for neighbor that sent the message).
761 * @param msg Message itself.
764 handle_tunnel_encrypted (void *cls,
765 const struct GNUNET_CADET_TunnelEncryptedMessage *msg)
767 struct CadetPeer *peer = cls;
768 struct CadetConnection *cc;
770 /* First, check if message belongs to a connection that ends here. */
771 cc = GNUNET_CONTAINER_multishortmap_get (connections,
772 &msg->cid.connection_of_tunnel);
775 /* verify message came from the right direction */
776 struct CadetPeerPath *path = GCC_get_path (cc);
779 GCPP_get_peer_at_offset (path,
782 /* received message from unexpected direction, ignore! */
786 GCC_handle_encrypted (cc,
790 /* We're just an intermediary peer, route the message along its path */
798 * Function called after #GNUNET_CORE_connect has succeeded (or failed
799 * for good). Note that the private key of the peer is intentionally
800 * not exposed here; if you need it, your process should try to read
801 * the private key file directly (which should work if you are
802 * authorized...). Implementations of this function must not call
803 * #GNUNET_CORE_disconnect (other than by scheduling a new task to
807 * @param my_identity ID of this peer, NULL if we failed
810 core_init_cb (void *cls,
811 const struct GNUNET_PeerIdentity *my_identity)
813 if (NULL == my_identity)
821 sizeof (struct GNUNET_PeerIdentity)));
826 * Method called whenever a given peer connects.
829 * @param peer peer identity this notification is about
832 core_connect_cb (void *cls,
833 const struct GNUNET_PeerIdentity *peer,
834 struct GNUNET_MQ_Handle *mq)
836 struct CadetPeer *cp;
838 LOG (GNUNET_ERROR_TYPE_DEBUG,
839 "CORE connection to peer %s was established.\n",
850 * Method called whenever a peer disconnects.
853 * @param peer peer identity this notification is about
856 core_disconnect_cb (void *cls,
857 const struct GNUNET_PeerIdentity *peer,
860 struct CadetPeer *cp = peer_cls;
862 LOG (GNUNET_ERROR_TYPE_DEBUG,
863 "CORE connection to peer %s went down.\n",
871 * Initialize the CORE subsystem.
873 * @param c Configuration.
876 GCO_init (const struct GNUNET_CONFIGURATION_Handle *c)
878 struct GNUNET_MQ_MessageHandler handlers[] = {
879 GNUNET_MQ_hd_var_size (connection_create,
880 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE,
881 struct GNUNET_CADET_ConnectionCreateMessage,
883 GNUNET_MQ_hd_fixed_size (connection_create_ack,
884 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK,
885 struct GNUNET_CADET_ConnectionCreateAckMessage,
887 GNUNET_MQ_hd_fixed_size (connection_broken,
888 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN,
889 struct GNUNET_CADET_ConnectionBrokenMessage,
891 GNUNET_MQ_hd_fixed_size (connection_destroy,
892 GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY,
893 struct GNUNET_CADET_ConnectionDestroyMessage,
895 GNUNET_MQ_hd_fixed_size (tunnel_kx,
896 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX,
897 struct GNUNET_CADET_TunnelKeyExchangeMessage,
899 GNUNET_MQ_hd_var_size (tunnel_encrypted,
900 GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED,
901 struct GNUNET_CADET_TunnelEncryptedMessage,
903 GNUNET_MQ_handler_end ()
906 routes = GNUNET_CONTAINER_multishortmap_create (1024,
908 core = GNUNET_CORE_connect (c,
918 * Shut down the CORE subsystem.
925 GNUNET_CORE_disconnect (core);
928 GNUNET_assert (0 == GNUNET_CONTAINER_multishortmap_size (routes));
929 GNUNET_CONTAINER_multishortmap_destroy (routes);
932 /* end of gnunet-cadet-service_core.c */