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23 * @file cadet/gnunet-service-cadet_tunnels.h
24 * @brief Information we track per tunnel.
25 * @author Bartlomiej Polot
26 * @author Christian Grothoff
28 #ifndef GNUNET_SERVICE_CADET_TUNNELS_H
29 #define GNUNET_SERVICE_CADET_TUNNELS_H
31 #include "gnunet-service-cadet.h"
32 #include "cadet_protocol.h"
36 * How many connections would we like to have per tunnel?
38 #define DESIRED_CONNECTIONS_PER_TUNNEL 3
42 * All the encryption states a tunnel can be in.
44 enum CadetTunnelEState
47 * Uninitialized status, we need to send KX. We will stay
48 * in this state until the first connection is up.
50 CADET_TUNNEL_KEY_UNINITIALIZED,
53 * KX message sent, waiting for other peer's KX_AUTH.
55 CADET_TUNNEL_KEY_AX_SENT,
58 * KX message received, trying to send back KX_AUTH.
60 CADET_TUNNEL_KEY_AX_RECV,
63 * KX message sent and received, trying to send back KX_AUTH.
65 CADET_TUNNEL_KEY_AX_SENT_AND_RECV,
68 * KX received and we sent KX_AUTH back, but we got no traffic yet,
69 * so we're waiting for either KX_AUTH or ENCRYPED traffic from
72 * We will not yet send traffic, as this might have been a replay.
73 * The other (initiating) peer should send a CHANNEL_OPEN next
74 * anyway, and then we are in business!
76 CADET_TUNNEL_KEY_AX_AUTH_SENT,
79 * Handshake completed: session key available.
87 * Get the static string for the peer this tunnel is directed.
91 * @return Static string the destination peer's ID.
94 GCT_2s (const struct CadetTunnel *t);
98 * Create a tunnel to @a destionation. Must only be called
99 * from within #GCP_get_tunnel().
101 * @param destination where to create the tunnel to
102 * @return new tunnel to @a destination
105 GCT_create_tunnel (struct CadetPeer *destination);
109 * Destroys the tunnel @a t now, without delay. Used during shutdown.
111 * @param t tunnel to destroy
114 GCT_destroy_tunnel_now (struct CadetTunnel *t);
118 * Add a @a connection to the @a tunnel.
121 * @param cid connection identifer to use for the connection
122 * @param options options for the connection
123 * @param path path to use for the connection
124 * @return #GNUNET_OK on success,
125 * #GNUNET_SYSERR on failure (duplicate connection)
128 GCT_add_inbound_connection (struct CadetTunnel *t,
129 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
130 enum GNUNET_CADET_ChannelOption options,
131 struct CadetPeerPath *path);
135 * We lost a connection, remove it from our list and clean up
136 * the connection object itself.
138 * @param ct binding of connection to tunnel of the connection that was lost.
141 GCT_connection_lost (struct CadetTConnection *ct);
145 * Return the peer to which this tunnel goes.
148 * @return the destination of the tunnel
151 GCT_get_destination (struct CadetTunnel *t);
155 * Consider using the path @a p for the tunnel @a t.
156 * The tunnel destination is at offset @a off in path @a p.
158 * @param cls our tunnel
159 * @param path a path to our destination
160 * @param off offset of the destination on path @a path
163 GCT_consider_path (struct CadetTunnel *t,
164 struct CadetPeerPath *p,
169 * Add a channel to a tunnel.
173 * @return unique number identifying @a ch within @a t
175 struct GNUNET_CADET_ChannelTunnelNumber
176 GCT_add_channel (struct CadetTunnel *t,
177 struct CadetChannel *ch);
181 * Remove a channel from a tunnel.
185 * @param ctn unique number identifying @a ch within @a t
188 GCT_remove_channel (struct CadetTunnel *t,
189 struct CadetChannel *ch,
190 struct GNUNET_CADET_ChannelTunnelNumber ctn);
194 * Send a DESTROY message via the tunnel.
196 * @param t the tunnel to transmit over
197 * @param ctn ID of the channel to destroy
200 GCT_send_channel_destroy (struct CadetTunnel *t,
201 struct GNUNET_CADET_ChannelTunnelNumber ctn);
205 * Function called when a transmission requested using #GCT_send is done.
208 * @param ctn identifier of the connection used for transmission, NULL if
209 * the transmission failed (to be used to match ACKs to the
210 * respective connection for connection performance evaluation)
213 (*GCT_SendContinuation)(void *cls,
214 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid);
218 * Sends an already built message on a tunnel, encrypting it and
219 * choosing the best connection if not provided.
221 * @param message Message to send. Function modifies it.
222 * @param t Tunnel on which this message is transmitted.
223 * @param cont Continuation to call once message is really sent.
224 * @param cont_cls Closure for @c cont.
225 * @return Handle to cancel message.
227 struct CadetTunnelQueueEntry *
228 GCT_send (struct CadetTunnel *t,
229 const struct GNUNET_MessageHeader *message,
230 GCT_SendContinuation cont,
235 * Cancel a previously sent message while it's in the queue.
237 * ONLY can be called before the continuation given to the send
238 * function is called. Once the continuation is called, the message is
239 * no longer in the queue!
241 * @param q Handle to the queue entry to cancel.
244 GCT_send_cancel (struct CadetTunnelQueueEntry *q);
248 * Return the number of channels using a tunnel.
250 * @param t tunnel to count obtain the number of channels for
251 * @return number of channels using the tunnel
254 GCT_count_channels (struct CadetTunnel *t);
258 * Return the number of connections available for a tunnel.
260 * @param t tunnel to count obtain the number of connections for
261 * @return number of connections available for the tunnel
264 GCT_count_any_connections (const struct CadetTunnel *t);
268 * Iterator over connections.
271 * @param ct one of the connections
274 (*GCT_ConnectionIterator) (void *cls,
275 struct CadetTConnection *ct);
279 * Iterate over all connections of a tunnel.
281 * @param t Tunnel whose connections to iterate.
282 * @param iter Iterator.
283 * @param iter_cls Closure for @c iter.
286 GCT_iterate_connections (struct CadetTunnel *t,
287 GCT_ConnectionIterator iter,
292 * Iterator over channels.
295 * @param ch one of the channels
298 (*GCT_ChannelIterator) (void *cls,
299 struct CadetChannel *ch);
303 * Iterate over all channels of a tunnel.
305 * @param t Tunnel whose channels to iterate.
306 * @param iter Iterator.
307 * @param iter_cls Closure for @c iter.
310 GCT_iterate_channels (struct CadetTunnel *t,
311 GCT_ChannelIterator iter,
316 * Get the encryption state of a tunnel.
320 * @return Tunnel's encryption state.
322 enum CadetTunnelEState
323 GCT_get_estate (struct CadetTunnel *t);
329 * @param ct connection/tunnel combo that received encrypted message
330 * @param msg the key exchange message
333 GCT_handle_kx (struct CadetTConnection *ct,
334 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg);
338 * Handle KX_AUTH message.
340 * @param ct connection/tunnel combo that received encrypted message
341 * @param msg the key exchange message
344 GCT_handle_kx_auth (struct CadetTConnection *ct,
345 const struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg);
349 * Handle encrypted message.
351 * @param ct connection/tunnel combo that received encrypted message
352 * @param msg the encrypted message to decrypt
355 GCT_handle_encrypted (struct CadetTConnection *ct,
356 const struct GNUNET_CADET_TunnelEncryptedMessage *msg);
360 * Log all possible info about the tunnel state.
362 * @param t Tunnel to debug.
363 * @param level Debug level to use.
366 GCT_debug (const struct CadetTunnel *t,
367 enum GNUNET_ErrorType level);