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17 * @file cadet/gnunet-service-cadet_channel.h
18 * @brief GNUnet CADET service with encryption
19 * @author Bartlomiej Polot
20 * @author Christian Grothoff
22 #ifndef GNUNET_SERVICE_CADET_CHANNEL_H
23 #define GNUNET_SERVICE_CADET_CHANNEL_H
25 #include "gnunet-service-cadet.h"
26 #include "gnunet-service-cadet_peer.h"
27 #include "cadet_protocol.h"
31 * A channel is a bidirectional connection between two CADET
32 * clients. Communiation can be reliable, unreliable, in-order
33 * or out-of-order. One client is the "local" client, this
34 * one initiated the connection. The other client is the
35 * "incoming" client, this one listened on a port to accept
36 * the connection from the "local" client.
42 * Hash the @a port and @a initiator and @a listener to
43 * calculate the "challenge" @a h_port we send to the other
44 * peer on #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN.
46 * @param[out] h_port set to the hash of @a port, @a initiator and @a listener
47 * @param port cadet port, as seen by CADET clients
48 * @param listener peer that is listining on @a port
51 GCCH_hash_port (struct GNUNET_HashCode *h_port,
52 const struct GNUNET_HashCode *port,
53 const struct GNUNET_PeerIdentity *listener);
57 * Get the static string for identification of the channel.
61 * @return Static string with the channel IDs.
64 GCCH_2s (const struct CadetChannel *ch);
71 * @param level Debug level to use.
74 GCCH_debug (struct CadetChannel *ch,
75 enum GNUNET_ErrorType level);
79 * Get the channel's public ID.
83 * @return ID used to identify the channel with the remote peer.
85 struct GNUNET_CADET_ChannelTunnelNumber
86 GCCH_get_id (const struct CadetChannel *ch);
90 * Create a new channel.
92 * @param owner local client owning the channel
93 * @param owner_id local chid of this channel at the @a owner
94 * @param destination peer to which we should build the channel
95 * @param port desired port at @a destination
96 * @param options options for the channel
97 * @return handle to the new channel
100 GCCH_channel_local_new (struct CadetClient *owner,
101 struct GNUNET_CADET_ClientChannelNumber owner_id,
102 struct CadetPeer *destination,
103 const struct GNUNET_HashCode *port,
108 * A client is bound to the port that we have a channel
109 * open to. Send the acknowledgement for the connection
110 * request and establish the link with the client.
112 * @param ch open incoming channel
113 * @param c client listening on the respective @a port
114 * @param port port number @a c is listening on
117 GCCH_bind (struct CadetChannel *ch,
118 struct CadetClient *c,
119 const struct GNUNET_HashCode *port);
123 * Destroy locally created channel. Called by the
124 * local client, so no need to tell the client.
126 * @param ch channel to destroy
127 * @param c client that caused the destruction
128 * @param ccn client number of the client @a c
131 GCCH_channel_local_destroy (struct CadetChannel *ch,
132 struct CadetClient *c,
133 struct GNUNET_CADET_ClientChannelNumber ccn);
137 * Function called once and only once after a channel was bound
138 * to its tunnel via #GCT_add_channel() is ready for transmission.
139 * Note that this is only the case for channels that this peer
140 * initiates, as for incoming channels we assume that they are
141 * ready for transmission immediately upon receiving the open
142 * message. Used to bootstrap the #GCT_send() process.
144 * @param ch the channel for which the tunnel is now ready
147 GCCH_tunnel_up (struct CadetChannel *ch);
151 * Create a new channel based on a request coming in over the network.
153 * @param t tunnel to the remote peer
154 * @param chid identifier of this channel in the tunnel
155 * @param origin peer to who initiated the channel
156 * @param h_port hash of desired local port
157 * @param options options for the channel
158 * @return handle to the new channel
160 struct CadetChannel *
161 GCCH_channel_incoming_new (struct CadetTunnel *t,
162 struct GNUNET_CADET_ChannelTunnelNumber chid,
163 const struct GNUNET_HashCode *h_port,
168 * We got a #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN message again for
169 * this channel. If the binding was successful, (re)transmit the
170 * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK.
172 * @param ch channel that got the duplicate open
173 * @param cti identifier of the connection that delivered the message
176 GCCH_handle_duplicate_open (struct CadetChannel *ch,
177 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti);
182 * We got payload data for a channel. Pass it on to the client.
184 * @param ch channel that got data
185 * @param cti identifier of the connection that delivered the message
186 * @param msg message that was received
189 GCCH_handle_channel_plaintext_data (struct CadetChannel *ch,
190 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
191 const struct GNUNET_CADET_ChannelAppDataMessage *msg);
195 * We got an acknowledgement for payload data for a channel.
196 * Possibly resume transmissions.
198 * @param ch channel that got the ack
199 * @param cti identifier of the connection that delivered the message
200 * @param ack details about what was received
203 GCCH_handle_channel_plaintext_data_ack (struct CadetChannel *ch,
204 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
205 const struct GNUNET_CADET_ChannelDataAckMessage *ack);
209 * We got an acknowledgement for the creation of the channel
210 * (the port is open on the other side). Begin transmissions.
212 * @param ch channel to destroy
213 * @param cti identifier of the connection that delivered the message,
214 * NULL if the ACK was inferred because we got payload or are on loopback
215 * @param port port number (needed to verify receiver knows the port)
218 GCCH_handle_channel_open_ack (struct CadetChannel *ch,
219 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
220 const struct GNUNET_HashCode *port);
224 * Destroy channel, based on the other peer closing the
225 * connection. Also needs to remove this channel from
228 * FIXME: need to make it possible to defer destruction until we have
229 * received all messages up to the destroy, and right now the destroy
230 * message (and this API) fails to give is the information we need!
232 * FIXME: also need to know if the other peer got a destroy from
235 * @param ch channel to destroy
236 * @param cti identifier of the connection that delivered the message,
237 * NULL during shutdown
240 GCCH_handle_remote_destroy (struct CadetChannel *ch,
241 const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti);
245 * Handle data given by a client.
247 * Check whether the client is allowed to send in this tunnel, save if
248 * channel is reliable and send an ACK to the client if there is still
249 * buffer space in the tunnel.
252 * @param sender_ccn ccn of the sender
253 * @param buf payload to transmit.
254 * @param buf_len number of bytes in @a buf
255 * @return #GNUNET_OK if everything goes well,
256 * #GNUNET_SYSERR in case of an error.
259 GCCH_handle_local_data (struct CadetChannel *ch,
260 struct GNUNET_CADET_ClientChannelNumber sender_ccn,
266 * Handle ACK from client on local channel.
268 * @param ch channel to destroy
269 * @param client_ccn ccn of the client sending the ack
272 GCCH_handle_local_ack (struct CadetChannel *ch,
273 struct GNUNET_CADET_ClientChannelNumber client_ccn);