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23 * @file cadet/gnunet-service-cadet-new_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-new.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 * Sends an already built message on a tunnel, encrypting it and
206 * choosing the best connection if not provided.
208 * @param message Message to send. Function modifies it.
209 * @param t Tunnel on which this message is transmitted.
210 * @param cont Continuation to call once message is really sent.
211 * @param cont_cls Closure for @c cont.
212 * @return Handle to cancel message.
214 struct CadetTunnelQueueEntry *
215 GCT_send (struct CadetTunnel *t,
216 const struct GNUNET_MessageHeader *message,
217 GNUNET_SCHEDULER_TaskCallback cont,
222 * Cancel a previously sent message while it's in the queue.
224 * ONLY can be called before the continuation given to the send
225 * function is called. Once the continuation is called, the message is
226 * no longer in the queue!
228 * @param q Handle to the queue entry to cancel.
231 GCT_send_cancel (struct CadetTunnelQueueEntry *q);
235 * Return the number of channels using a tunnel.
237 * @param t tunnel to count obtain the number of channels for
238 * @return number of channels using the tunnel
241 GCT_count_channels (struct CadetTunnel *t);
245 * Return the number of connections available for a tunnel.
247 * @param t tunnel to count obtain the number of connections for
248 * @return number of connections available for the tunnel
251 GCT_count_any_connections (const struct CadetTunnel *t);
255 * Iterator over connections.
258 * @param ct one of the connections
261 (*GCT_ConnectionIterator) (void *cls,
262 struct CadetTConnection *ct);
266 * Iterate over all connections of a tunnel.
268 * @param t Tunnel whose connections to iterate.
269 * @param iter Iterator.
270 * @param iter_cls Closure for @c iter.
273 GCT_iterate_connections (struct CadetTunnel *t,
274 GCT_ConnectionIterator iter,
279 * Iterator over channels.
282 * @param ch one of the channels
285 (*GCT_ChannelIterator) (void *cls,
286 struct CadetChannel *ch);
290 * Iterate over all channels of a tunnel.
292 * @param t Tunnel whose channels to iterate.
293 * @param iter Iterator.
294 * @param iter_cls Closure for @c iter.
297 GCT_iterate_channels (struct CadetTunnel *t,
298 GCT_ChannelIterator iter,
303 * Get the encryption state of a tunnel.
307 * @return Tunnel's encryption state.
309 enum CadetTunnelEState
310 GCT_get_estate (struct CadetTunnel *t);
316 * @param ct connection/tunnel combo that received encrypted message
317 * @param msg the key exchange message
320 GCT_handle_kx (struct CadetTConnection *ct,
321 const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg);
325 * Handle KX_AUTH message.
327 * @param ct connection/tunnel combo that received encrypted message
328 * @param msg the key exchange message
331 GCT_handle_kx_auth (struct CadetTConnection *ct,
332 const struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg);
336 * Handle encrypted message.
338 * @param ct connection/tunnel combo that received encrypted message
339 * @param msg the encrypted message to decrypt
342 GCT_handle_encrypted (struct CadetTConnection *ct,
343 const struct GNUNET_CADET_TunnelEncryptedMessage *msg);
347 * Log all possible info about the tunnel state.
349 * @param t Tunnel to debug.
350 * @param level Debug level to use.
353 GCT_debug (const struct CadetTunnel *t,
354 enum GNUNET_ErrorType level);