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22 * @file cadet/gnunet-service-cadet_tunnel.h
23 * @brief cadet service; dealing with tunnels and crypto
24 * @author Bartlomiej Polot
26 * All functions in this file should use the prefix GMT (Gnunet Cadet Tunnel)
29 #ifndef GNUNET_SERVICE_CADET_TUNNEL_H
30 #define GNUNET_SERVICE_CADET_TUNNEL_H
35 #if 0 /* keep Emacsens' auto-indent happy */
41 #include "gnunet_util_lib.h"
43 #define CONNECTIONS_PER_TUNNEL 3
46 * All the connectivity states a tunnel can be in.
48 enum CadetTunnelCState
51 * Uninitialized status, should never appear in operation.
56 * No path to the peer known yet.
58 CADET_TUNNEL_SEARCHING,
61 * Request sent, not yet answered.
66 * Peer connected and ready to accept data.
71 * Tunnel being shut down, don't try to keep it alive.
78 * All the encryption states a tunnel can be in.
80 enum CadetTunnelEState
83 * Uninitialized status, should never appear in operation.
85 CADET_TUNNEL_KEY_UNINITIALIZED,
88 * Ephemeral key sent, waiting for peer's key.
90 CADET_TUNNEL_KEY_SENT,
93 * New ephemeral key and ping sent, waiting for pong.
94 * This means that we DO have the peer's ephemeral key, otherwise the
95 * state would be KEY_SENT. We DO NOT have a valid session key (either no
96 * previous key or previous key expired).
98 CADET_TUNNEL_KEY_PING,
101 * Handshake completed: session key available.
106 * New ephemeral key and ping sent, waiting for pong. Unlike KEY_PING,
107 * we still have a valid session key and therefore we *can* still send
108 * traffic on the tunnel.
110 CADET_TUNNEL_KEY_REKEY,
114 * Struct containing all information regarding a given peer
119 #include "gnunet-service-cadet_channel.h"
120 #include "gnunet-service-cadet_connection.h"
121 #include "gnunet-service-cadet_peer.h"
124 * Handle for messages queued but not yet sent.
126 struct CadetTunnelQueue;
129 * Callback called when a queued message is sent.
131 * @param cls Closure.
132 * @param t Tunnel this message was on.
133 * @param type Type of message sent.
134 * @param size Size of the message.
136 typedef void (*GCT_sent) (void *cls,
137 struct CadetTunnel *t,
138 struct CadetTunnelQueue *q,
139 uint16_t type, size_t size);
141 typedef void (*GCT_conn_iter) (void *cls, struct CadetConnection *c);
142 typedef void (*GCT_chan_iter) (void *cls, struct CadetChannel *ch);
145 /******************************************************************************/
146 /******************************** API ***********************************/
147 /******************************************************************************/
150 * Initialize tunnel subsystem.
152 * @param c Configuration handle.
153 * @param key ECC private key, to derive all other keys and do crypto.
156 GCT_init (const struct GNUNET_CONFIGURATION_Handle *c,
157 const struct GNUNET_CRYPTO_EddsaPrivateKey *key);
160 * Shut down the tunnel subsystem.
168 * @param destination Peer this tunnel is towards.
171 GCT_new (struct CadetPeer *destination);
174 * Tunnel is empty: destroy it.
176 * Notifies all connections about the destruction.
178 * @param t Tunnel to destroy.
181 GCT_destroy_empty (struct CadetTunnel *t);
184 * Destroy tunnel if empty (no more channels).
186 * @param t Tunnel to destroy if empty.
189 GCT_destroy_if_empty (struct CadetTunnel *t);
192 * Destroy the tunnel.
194 * This function does not generate any warning traffic to clients or peers.
197 * Cancel messages belonging to this tunnel queued to neighbors.
198 * Free any allocated resources linked to the tunnel.
200 * @param t The tunnel to destroy.
203 GCT_destroy (struct CadetTunnel *t);
207 * Change the tunnel's connection state.
209 * @param t Tunnel whose connection state to change.
210 * @param cstate New connection state.
213 GCT_change_cstate (struct CadetTunnel* t, enum CadetTunnelCState cstate);
217 * Change the tunnel encryption state.
219 * @param t Tunnel whose encryption state to change.
220 * @param state New encryption state.
223 GCT_change_estate (struct CadetTunnel* t, enum CadetTunnelEState state);
226 * Add a connection to a tunnel.
229 * @param c Connection.
232 GCT_add_connection (struct CadetTunnel *t, struct CadetConnection *c);
235 * Remove a connection from a tunnel.
238 * @param c Connection.
241 GCT_remove_connection (struct CadetTunnel *t, struct CadetConnection *c);
244 * Add a channel to a tunnel.
250 GCT_add_channel (struct CadetTunnel *t, struct CadetChannel *ch);
253 * Remove a channel from a tunnel.
259 GCT_remove_channel (struct CadetTunnel *t, struct CadetChannel *ch);
262 * Search for a channel by global ID.
264 * @param t Tunnel containing the channel.
265 * @param chid Public channel number.
267 * @return channel handler, NULL if doesn't exist
269 struct CadetChannel *
270 GCT_get_channel (struct CadetTunnel *t, CADET_ChannelNumber chid);
273 * Decrypt and demultiplex by message type. Call appropriate handler
275 * towards a channel of a local tunnel.
277 * @param t Tunnel this message came on.
278 * @param msg Message header.
281 GCT_handle_encrypted (struct CadetTunnel *t,
282 const struct GNUNET_CADET_Encrypted *msg);
285 * Demultiplex an encapsulated KX message by message type.
287 * @param t Tunnel on which the message came.
288 * @param message KX message itself.
291 GCT_handle_kx (struct CadetTunnel *t,
292 const struct GNUNET_MessageHeader *message);
295 * @brief Use the given path for the tunnel.
296 * Update the next and prev hops (and RCs).
297 * (Re)start the path refresh in case the tunnel is locally owned.
299 * @param t Tunnel to update.
300 * @param p Path to use.
302 * @return Connection created.
304 struct CadetConnection *
305 GCT_use_path (struct CadetTunnel *t, struct CadetPeerPath *p);
308 * Count all created connections of a tunnel. Not necessarily ready connections!
310 * @param t Tunnel on which to count.
312 * @return Number of connections created, either being established or ready.
315 GCT_count_any_connections (struct CadetTunnel *t);
318 * Count established (ready) connections of a tunnel.
320 * @param t Tunnel on which to count.
322 * @return Number of connections.
325 GCT_count_connections (struct CadetTunnel *t);
328 * Count channels of a tunnel.
330 * @param t Tunnel on which to count.
332 * @return Number of channels.
335 GCT_count_channels (struct CadetTunnel *t);
338 * Get the connectivity state of a tunnel.
342 * @return Tunnel's connectivity state.
344 enum CadetTunnelCState
345 GCT_get_cstate (struct CadetTunnel *t);
348 * Get the encryption state of a tunnel.
352 * @return Tunnel's encryption state.
354 enum CadetTunnelEState
355 GCT_get_estate (struct CadetTunnel *t);
358 * Get the maximum buffer space for a tunnel towards a local client.
362 * @return Biggest buffer space offered by any channel in the tunnel.
365 GCT_get_channels_buffer (struct CadetTunnel *t);
368 * Get the total buffer space for a tunnel for P2P traffic.
372 * @return Buffer space offered by all connections in the tunnel.
375 GCT_get_connections_buffer (struct CadetTunnel *t);
378 * Get the tunnel's destination.
382 * @return ID of the destination peer.
384 const struct GNUNET_PeerIdentity *
385 GCT_get_destination (struct CadetTunnel *t);
388 * Get the tunnel's next free Channel ID.
392 * @return ID of a channel free to use.
395 GCT_get_next_chid (struct CadetTunnel *t);
398 * Send ACK on one or more channels due to buffer in connections.
400 * @param t Channel which has some free buffer space.
403 GCT_unchoke_channels (struct CadetTunnel *t);
406 * Send ACK on one or more connections due to buffer space to the client.
408 * Iterates all connections of the tunnel and sends ACKs appropriately.
410 * @param t Tunnel which has some free buffer space.
413 GCT_send_connection_acks (struct CadetTunnel *t);
416 * Cancel a previously sent message while it's in the queue.
418 * ONLY can be called before the continuation given to the send function
419 * is called. Once the continuation is called, the message is no longer in the
422 * @param q Handle to the queue.
425 GCT_cancel (struct CadetTunnelQueue *q);
428 * Sends an already built message on a tunnel, encrypting it and
429 * choosing the best connection.
431 * @param message Message to send. Function modifies it.
432 * @param t Tunnel on which this message is transmitted.
433 * @param c Connection to use (autoselect if NULL).
434 * @param force Force the tunnel to take the message (buffer overfill).
435 * @param cont Continuation to call once message is really sent.
436 * @param cont_cls Closure for @c cont.
438 * @return Handle to cancel message. NULL if @c cont is NULL.
440 struct CadetTunnelQueue *
441 GCT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
442 struct CadetTunnel *t, struct CadetConnection *c,
443 int force, GCT_sent cont, void *cont_cls);
446 * Sends an already built and encrypted message on a tunnel, choosing the best
447 * connection. Useful for re-queueing messages queued on a destroyed connection.
449 * @param message Message to send. Function modifies it.
450 * @param t Tunnel on which this message is transmitted.
453 GCT_resend_message (const struct GNUNET_MessageHeader *message,
454 struct CadetTunnel *t);
457 * Is the tunnel directed towards the local peer?
461 * @return #GNUNET_YES if it is loopback.
464 GCT_is_loopback (const struct CadetTunnel *t);
467 * Is the tunnel using this path already?
472 * @return #GNUNET_YES a connection uses this path.
475 GCT_is_path_used (const struct CadetTunnel *t, const struct CadetPeerPath *p);
478 * Get a cost of a path for a tunnel considering existing connections.
481 * @param path Candidate path.
483 * @return Cost of the path (path length + number of overlapping nodes)
486 GCT_get_path_cost (const struct CadetTunnel *t,
487 const struct CadetPeerPath *path);
490 * Get the static string for the peer this tunnel is directed.
494 * @return Static string the destination peer's ID.
497 GCT_2s (const struct CadetTunnel *t);
500 * Log all possible info about the tunnel state.
502 * @param t Tunnel to debug.
503 * @param level Debug level to use.
506 GCT_debug (const struct CadetTunnel *t, enum GNUNET_ErrorType level);
509 * Iterate all tunnels.
511 * @param iter Iterator.
512 * @param cls Closure for @c iter.
515 GCT_iterate_all (GNUNET_CONTAINER_PeerMapIterator iter, void *cls);
520 * @return Number of tunnels to remote peers kept by this peer.
523 GCT_count_all (void);
526 * Iterate all connections of a tunnel.
528 * @param t Tunnel whose connections to iterate.
529 * @param iter Iterator.
530 * @param cls Closure for @c iter.
533 GCT_iterate_connections (struct CadetTunnel *t, GCT_conn_iter iter, void *cls);
536 * Iterate all channels of a tunnel.
538 * @param t Tunnel whose channels to iterate.
539 * @param iter Iterator.
540 * @param cls Closure for @c iter.
543 GCT_iterate_channels (struct CadetTunnel *t, GCT_chan_iter iter, void *cls);
545 #if 0 /* keep Emacsens' auto-indent happy */
552 /* ifndef GNUNET_CADET_SERVICE_TUNNEL_H */
554 /* end of gnunet-cadet-service_tunnel.h */