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22 * @file cadet/gnunet-service-cadet_channel.h
23 * @brief cadet service; dealing with end-to-end channels
24 * @author Bartlomiej Polot
26 * All functions in this file should use the prefix GMCH (Gnunet Cadet CHannel)
29 #ifndef GNUNET_SERVICE_CADET_CHANNEL_H
30 #define GNUNET_SERVICE_CADET_CHANNEL_H
35 #if 0 /* keep Emacsens' auto-indent happy */
41 #include "gnunet_util_lib.h"
43 #include "cadet_protocol.h"
47 * Struct containing all information regarding a channel to a remote client.
52 #include "gnunet-service-cadet_tunnel.h"
53 #include "gnunet-service-cadet_local.h"
57 * Destroy a channel and free all resources.
59 * @param ch Channel to destroy.
62 GCCH_destroy (struct CadetChannel *ch);
66 * Get the channel's public ID.
70 * @return ID used to identify the channel with the remote peer.
73 GCCH_get_id (const struct CadetChannel *ch);
76 * Get the channel tunnel.
78 * @param ch Channel to get the tunnel from.
80 * @return tunnel of the channel.
83 GCCH_get_tunnel (const struct CadetChannel *ch);
86 * Get free buffer space towards the client on a specific channel.
89 * @param fwd Is query about FWD traffic?
91 * @return Free buffer space [0 - 64]
94 GCCH_get_buffer (struct CadetChannel *ch, int fwd);
98 * Get flow control status of end point: is client allow to send?
101 * @param fwd Is query about FWD traffic? (Request root status).
103 * @return #GNUNET_YES if client is allowed to send us data.
106 GCCH_get_allowed (struct CadetChannel *ch, int fwd);
110 * Is the root client for this channel on this peer?
113 * @param fwd Is this for fwd traffic?
115 * @return #GNUNET_YES in case it is.
118 GCCH_is_origin (struct CadetChannel *ch, int fwd);
121 * Is the destination client for this channel on this peer?
124 * @param fwd Is this for fwd traffic?
126 * @return #GNUNET_YES in case it is.
129 GCCH_is_terminal (struct CadetChannel *ch, int fwd);
132 * Send an end-to-end ACK message for the most recent in-sequence payload.
134 * If channel is not reliable, do nothing.
136 * @param ch Channel this is about.
137 * @param fwd Is for FWD traffic? (ACK dest->owner)
140 GCCH_send_data_ack (struct CadetChannel *ch, int fwd);
143 * Notify the destination client that a new incoming channel was created.
145 * @param ch Channel that was created.
148 GCCH_send_create (struct CadetChannel *ch);
151 * Allow a client to send us more data, in case it was choked.
154 * @param fwd Is this about FWD traffic? (Root client).
157 GCCH_allow_client (struct CadetChannel *ch, int fwd);
163 * @param level Debug level to use.
166 GCCH_debug (struct CadetChannel *ch, enum GNUNET_ErrorType level);
169 * Handle an ACK given by a client.
171 * Mark client as ready and send him any buffered data we could have for him.
174 * @param fwd Is this a "FWD ACK"? (FWD ACKs are sent by root and go BCK)
177 GCCH_handle_local_ack (struct CadetChannel *ch, int fwd);
180 * Handle data given by a client.
182 * Check whether the client is allowed to send in this tunnel, save if channel
183 * is reliable and send an ACK to the client if there is still buffer space
187 * @param c Client which sent the data.
188 * @param fwd Is this a FWD data?
189 * @param message Data message.
190 * @param size Size of data.
192 * @return GNUNET_OK if everything goes well, GNUNET_SYSERR in case of en error.
195 GCCH_handle_local_data (struct CadetChannel *ch,
196 struct CadetClient *c, int fwd,
197 const struct GNUNET_MessageHeader *message,
201 * Handle a channel destroy requested by a client.
203 * Destroy the channel and the tunnel in case this was the last channel.
206 * @param c Client that requested the destruction (to avoid notifying him).
207 * @param is_root Is the request coming from root?
210 GCCH_handle_local_destroy (struct CadetChannel *ch,
211 struct CadetClient *c,
216 * Handle a channel create requested by a client.
218 * Create the channel and the tunnel in case this was the first0 channel.
220 * @param c Client that requested the creation (will be the root).
221 * @param msg Create Channel message.
223 * @return #GNUNET_OK if everything went fine, #GNUNET_SYSERR otherwise.
226 GCCH_handle_local_create (struct CadetClient *c,
227 struct GNUNET_CADET_ChannelCreateMessage *msg);
230 * Handler for cadet network payload traffic.
232 * @param ch Channel for the message.
233 * @param msg Unencryted data message.
234 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
235 * #GNUNET_YES if message is FWD on the respective channel (loopback)
236 * #GNUNET_NO if message is BCK on the respective channel (loopback)
237 * #GNUNET_SYSERR if message on a one-ended channel (remote)
240 GCCH_handle_data (struct CadetChannel *ch,
241 const struct GNUNET_CADET_Data *msg,
246 * Handler for cadet network traffic end-to-end ACKs.
248 * @param ch Channel on which we got this message.
249 * @param msg Data message.
250 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
251 * #GNUNET_YES if message is FWD on the respective channel (loopback)
252 * #GNUNET_NO if message is BCK on the respective channel (loopback)
253 * #GNUNET_SYSERR if message on a one-ended channel (remote)
256 GCCH_handle_data_ack (struct CadetChannel *ch,
257 const struct GNUNET_CADET_DataACK *msg,
262 * Handler for channel create messages.
264 * Does not have fwd parameter because it's always 'FWD': channel is incoming.
266 * @param t Tunnel this channel will be in.
267 * @param msg Channel crate message.
269 struct CadetChannel *
270 GCCH_handle_create (struct CadetTunnel *t,
271 const struct GNUNET_CADET_ChannelCreate *msg);
275 * Handler for channel NACK messages.
277 * NACK messages always go dest -> root, no need for 'fwd' or 'msg' parameter.
282 GCCH_handle_nack (struct CadetChannel *ch);
286 * Handler for channel ack messages.
288 * @param ch Channel this channel is to be created in.
289 * @param msg Message.
290 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
291 * #GNUNET_YES if message is FWD on the respective channel (loopback)
292 * #GNUNET_NO if message is BCK on the respective channel (loopback)
293 * #GNUNET_SYSERR if message on a one-ended channel (remote)
296 GCCH_handle_ack (struct CadetChannel *ch,
297 const struct GNUNET_CADET_ChannelManage *msg,
302 * Handler for channel destroy messages.
304 * @param ch Channel this channel is to be destroyed of.
305 * @param msg Message.
306 * @param fwd Is this message fwd? This only is meaningful in loopback channels.
307 * #GNUNET_YES if message is FWD on the respective channel (loopback)
308 * #GNUNET_NO if message is BCK on the respective channel (loopback)
309 * #GNUNET_SYSERR if message on a one-ended channel (remote)
312 GCCH_handle_destroy (struct CadetChannel *ch,
313 const struct GNUNET_CADET_ChannelManage *msg,
318 * Sends an already built message on a channel.
320 * If the channel is on a loopback tunnel, notifies the appropriate destination
323 * On a normal channel passes the message to the tunnel for encryption and
324 * sending on a connection.
326 * This function DOES NOT save the message for retransmission.
328 * @param message Message to send. Function makes a copy of it.
329 * @param ch Channel on which this message is transmitted.
330 * @param fwd Is this a fwd message?
331 * @param existing_copy This is a retransmission, don't save a copy.
334 GCCH_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
335 struct CadetChannel *ch, int fwd,
336 void *existing_copy);
340 * Get the static string for identification of the channel.
342 * @param ch Channel.i
344 * @return Static string with the channel IDs.
347 GCCH_2s (const struct CadetChannel *ch);
350 #if 0 /* keep Emacsens' auto-indent happy */
357 /* ifndef GNUNET_SERVICE_CADET_CHANNEL_H */
359 /* end of gnunet-service-cadet_channel.h */