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20 * @file cadet/gnunet-service-cadet_channel.h
21 * @brief GNUnet CADET service with encryption
22 * @author Bartlomiej Polot
23 * @author Christian Grothoff
25 #ifndef GNUNET_SERVICE_CADET_CHANNEL_H
26 #define GNUNET_SERVICE_CADET_CHANNEL_H
28 #include "gnunet-service-cadet.h"
29 #include "gnunet-service-cadet_peer.h"
30 #include "cadet_protocol.h"
34 * A channel is a bidirectional connection between two CADET
35 * clients. Communiation can be reliable, unreliable, in-order
36 * or out-of-order. One client is the "local" client, this
37 * one initiated the connection. The other client is the
38 * "incoming" client, this one listened on a port to accept
39 * the connection from the "local" client.
45 * Hash the @a port and @a initiator and @a listener to
46 * calculate the "challenge" @a h_port we send to the other
47 * peer on #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN.
49 * @param[out] h_port set to the hash of @a port, @a initiator and @a listener
50 * @param port cadet port, as seen by CADET clients
51 * @param listener peer that is listining on @a port
54 GCCH_hash_port (struct GNUNET_HashCode *h_port,
55 const struct GNUNET_HashCode *port,
56 const struct GNUNET_PeerIdentity *listener);
60 * Get the static string for identification of the channel.
64 * @return Static string with the channel IDs.
67 GCCH_2s (const struct CadetChannel *ch);
74 * @param level Debug level to use.
77 GCCH_debug (struct CadetChannel *ch,
78 enum GNUNET_ErrorType level);
82 * Get the channel's public ID.
86 * @return ID used to identify the channel with the remote peer.
88 struct GNUNET_CADET_ChannelTunnelNumber
89 GCCH_get_id (const struct CadetChannel *ch);
93 * Create a new channel.
95 * @param owner local client owning the channel
96 * @param owner_id local chid of this channel at the @a owner
97 * @param destination peer to which we should build the channel
98 * @param port desired port at @a destination
99 * @param options options for the channel
100 * @return handle to the new channel
102 struct CadetChannel *
103 GCCH_channel_local_new (struct CadetClient *owner,
104 struct GNUNET_CADET_ClientChannelNumber owner_id,
105 struct CadetPeer *destination,
106 const struct GNUNET_HashCode *port,
111 * A client is bound to the port that we have a channel
112 * open to. Send the acknowledgement for the connection
113 * request and establish the link with the client.
115 * @param ch open incoming channel
116 * @param c client listening on the respective @a port
117 * @param port port number @a c is listening on
120 GCCH_bind (struct CadetChannel *ch,
121 struct CadetClient *c,
122 const struct GNUNET_HashCode *port);
126 * Destroy locally created channel. Called by the
127 * local client, so no need to tell the client.
129 * @param ch channel to destroy
130 * @param c client that caused the destruction
131 * @param ccn client number of the client @a c
134 GCCH_channel_local_destroy (struct CadetChannel *ch,
135 struct CadetClient *c,
136 struct GNUNET_CADET_ClientChannelNumber ccn);
140 * Function called once and only once after a channel was bound
141 * to its tunnel via #GCT_add_channel() is ready for transmission.
142 * Note that this is only the case for channels that this peer
143 * initiates, as for incoming channels we assume that they are
144 * ready for transmission immediately upon receiving the open
145 * message. Used to bootstrap the #GCT_send() process.
147 * @param ch the channel for which the tunnel is now ready
150 GCCH_tunnel_up (struct CadetChannel *ch);
154 * Create a new channel based on a request coming in over the network.
156 * @param t tunnel to the remote peer
157 * @param chid identifier of this channel in the tunnel
158 * @param origin peer to who initiated the channel
159 * @param h_port hash of desired local port
160 * @param options options for the channel
161 * @return handle to the new channel
163 struct CadetChannel *
164 GCCH_channel_incoming_new (struct CadetTunnel *t,
165 struct GNUNET_CADET_ChannelTunnelNumber chid,
166 const struct GNUNET_HashCode *h_port,
171 * We got a #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN message again for
172 * this channel. If the binding was successful, (re)transmit the
173 * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK.
175 * @param ch channel that got the duplicate open
176 * @param cti identifier of the connection that delivered the message
179 GCCH_handle_duplicate_open (struct CadetChannel *ch,
180 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti);
185 * We got payload data for a channel. Pass it on to the client.
187 * @param ch channel that got data
188 * @param cti identifier of the connection that delivered the message
189 * @param msg message that was received
192 GCCH_handle_channel_plaintext_data (struct CadetChannel *ch,
193 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
194 const struct GNUNET_CADET_ChannelAppDataMessage *msg);
198 * We got an acknowledgement for payload data for a channel.
199 * Possibly resume transmissions.
201 * @param ch channel that got the ack
202 * @param cti identifier of the connection that delivered the message
203 * @param ack details about what was received
206 GCCH_handle_channel_plaintext_data_ack (struct CadetChannel *ch,
207 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
208 const struct GNUNET_CADET_ChannelDataAckMessage *ack);
212 * We got an acknowledgement for the creation of the channel
213 * (the port is open on the other side). Begin transmissions.
215 * @param ch channel to destroy
216 * @param cti identifier of the connection that delivered the message,
217 * NULL if the ACK was inferred because we got payload or are on loopback
218 * @param port port number (needed to verify receiver knows the port)
221 GCCH_handle_channel_open_ack (struct CadetChannel *ch,
222 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
223 const struct GNUNET_HashCode *port);
227 * Destroy channel, based on the other peer closing the
228 * connection. Also needs to remove this channel from
231 * FIXME: need to make it possible to defer destruction until we have
232 * received all messages up to the destroy, and right now the destroy
233 * message (and this API) fails to give is the information we need!
235 * FIXME: also need to know if the other peer got a destroy from
238 * @param ch channel to destroy
239 * @param cti identifier of the connection that delivered the message,
240 * NULL during shutdown
243 GCCH_handle_remote_destroy (struct CadetChannel *ch,
244 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti);
248 * Handle data given by a client.
250 * Check whether the client is allowed to send in this tunnel, save if
251 * channel is reliable and send an ACK to the client if there is still
252 * buffer space in the tunnel.
255 * @param sender_ccn ccn of the sender
256 * @param buf payload to transmit.
257 * @param buf_len number of bytes in @a buf
258 * @return #GNUNET_OK if everything goes well,
259 * #GNUNET_SYSERR in case of an error.
262 GCCH_handle_local_data (struct CadetChannel *ch,
263 struct GNUNET_CADET_ClientChannelNumber sender_ccn,
269 * Handle ACK from client on local channel.
271 * @param ch channel to destroy
272 * @param client_ccn ccn of the client sending the ack
275 GCCH_handle_local_ack (struct CadetChannel *ch,
276 struct GNUNET_CADET_ClientChannelNumber client_ccn);