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22 * @file mesh/gnunet-service-mesh_connection.h
23 * @brief mesh service; dealing with connections
24 * @author Bartlomiej Polot
26 * All functions in this file should use the prefix GMC (Gnunet Mesh Connection)
29 #ifndef GNUNET_SERVICE_MESH_CONNECTION_H
30 #define GNUNET_SERVICE_MESH_CONNECTION_H
35 #if 0 /* keep Emacsens' auto-indent happy */
40 #include "gnunet_util_lib.h"
44 * All the states a connection can be in.
46 enum MeshConnectionState
49 * Uninitialized status, should never appear in operation.
54 * Connection create message sent, waiting for ACK.
59 * Connection ACK sent, waiting for ACK.
64 * Connection confirmed, ready to carry traffic.
66 MESH_CONNECTION_READY,
71 * Struct containing all information regarding a connection to a peer.
73 struct MeshConnection;
75 #include "mesh_path.h"
76 #include "gnunet-service-mesh_channel.h"
77 #include "gnunet-service-mesh_peer.h"
82 * Core handler for connection creation.
84 * @param cls Closure (unused).
85 * @param peer Sender (neighbor).
86 * @param message Message.
88 * @return GNUNET_OK to keep the connection open,
89 * GNUNET_SYSERR to close it (signal serious error)
92 GMC_handle_create (void *cls, const struct GNUNET_PeerIdentity *peer,
93 const struct GNUNET_MessageHeader *message);
96 * Core handler for path confirmations.
99 * @param message message
100 * @param peer peer identity this notification is about
102 * @return GNUNET_OK to keep the connection open,
103 * GNUNET_SYSERR to close it (signal serious error)
106 GMC_handle_confirm (void *cls, const struct GNUNET_PeerIdentity *peer,
107 const struct GNUNET_MessageHeader *message);
110 * Core handler for notifications of broken paths
112 * @param cls Closure (unused).
113 * @param id Peer identity of sending neighbor.
114 * @param message Message.
116 * @return GNUNET_OK to keep the connection open,
117 * GNUNET_SYSERR to close it (signal serious error)
120 GMC_handle_broken (void* cls,
121 const struct GNUNET_PeerIdentity* id,
122 const struct GNUNET_MessageHeader* message);
125 * Core handler for tunnel destruction
127 * @param cls Closure (unused).
128 * @param peer Peer identity of sending neighbor.
129 * @param message Message.
131 * @return GNUNET_OK to keep the connection open,
132 * GNUNET_SYSERR to close it (signal serious error)
135 GMC_handle_destroy (void *cls, const struct GNUNET_PeerIdentity *peer,
136 const struct GNUNET_MessageHeader *message);
139 * Core handler for encrypted mesh network traffic (channel mgmt, data).
141 * @param cls Closure (unused).
142 * @param message Message received.
143 * @param peer Peer who sent the message.
145 * @return GNUNET_OK to keep the connection open,
146 * GNUNET_SYSERR to close it (signal serious error)
149 GMC_handle_encrypted (void *cls, const struct GNUNET_PeerIdentity *peer,
150 const struct GNUNET_MessageHeader *message);
153 * Core handler for mesh network traffic point-to-point acks.
156 * @param message message
157 * @param peer peer identity this notification is about
159 * @return GNUNET_OK to keep the connection open,
160 * GNUNET_SYSERR to close it (signal serious error)
163 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
164 const struct GNUNET_MessageHeader *message);
167 * Core handler for mesh network traffic point-to-point ack polls.
170 * @param message message
171 * @param peer peer identity this notification is about
173 * @return GNUNET_OK to keep the connection open,
174 * GNUNET_SYSERR to close it (signal serious error)
177 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
178 const struct GNUNET_MessageHeader *message);
181 * Core handler for mesh keepalives.
184 * @param message message
185 * @param peer peer identity this notification is about
186 * @return GNUNET_OK to keep the connection open,
187 * GNUNET_SYSERR to close it (signal serious error)
189 * TODO: Check who we got this from, to validate route.
192 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
193 const struct GNUNET_MessageHeader *message);
196 * Send an ACK on the appropriate connection/channel, depending on
197 * the direction and the position of the peer.
199 * @param c Which connection to send the hop-by-hop ACK.
200 * @param ch Channel, if any.
201 * @param fwd Is this a fwd ACK? (will go dest->root)
204 GMC_send_ack (struct MeshConnection *c, struct MeshChannel *ch, int fwd);
207 * Initialize the connections subsystem
209 * @param c Configuration handle.
212 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c);
215 * Shut down the connections subsystem.
221 * Create a connection.
223 * @param cid Connection ID (either created locally or imposed remotely).
224 * @param t Tunnel this connection belongs to (or NULL);
225 * @param p Path this connection has to use.
226 * @param own_pos Own position in the @c p path.
228 struct MeshConnection *
229 GMC_new (const struct GNUNET_HashCode *cid,
230 struct MeshTunnel3 *t,
231 struct MeshPeerPath *p,
232 unsigned int own_pos);
235 * Connection is no longer needed: destroy it and remove from tunnel.
237 * @param c Connection to destroy.
240 GMC_destroy (struct MeshConnection *c);
243 * Get the connection ID.
245 * @param c Connection to get the ID from.
247 * @return ID of the connection.
249 const struct GNUNET_HashCode *
250 GMC_get_id (const struct MeshConnection *c);
253 * Get the connection path.
255 * @param c Connection to get the path from.
257 * @return path used by the connection.
259 const struct MeshPeerPath *
260 GMC_get_path (const struct MeshConnection *c);
263 * Get the connection state.
265 * @param c Connection to get the state from.
267 * @return state of the connection.
269 enum MeshConnectionState
270 GMC_get_state (const struct MeshConnection *c);
273 * Get the connection tunnel.
275 * @param c Connection to get the tunnel from.
277 * @return tunnel of the connection.
280 GMC_get_tunnel (const struct MeshConnection *c);
283 * Get free buffer space in a connection.
285 * @param c Connection.
286 * @param fwd Is query about FWD traffic?
288 * @return Free buffer space [0 - max_msgs_queue/max_connections]
291 GMC_get_buffer (struct MeshConnection *c, int fwd);
294 * Get how many messages have we allowed to send to us from a direction..
296 * @param c Connection.
297 * @param fwd Are we asking about traffic from FWD (BCK messages)?
299 * @return last_ack_sent - last_pid_recv
302 GMC_get_allowed (struct MeshConnection *c, int fwd);
305 * Get messages queued in a connection.
307 * @param c Connection.
308 * @param fwd Is query about FWD traffic?
310 * @return Number of messages queued.
313 GMC_get_qn (struct MeshConnection *c, int fwd);
316 * Allow the connection to advertise a buffer of the given size.
318 * The connection will send an @c fwd ACK message (so: in direction !fwd)
319 * allowing up to last_pid_recv + buffer.
321 * @param c Connection.
322 * @param buffer How many more messages the connection can accept.
323 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
326 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd);
329 * Send FWD keepalive packets for a connection.
331 * @param cls Closure (connection for which to send the keepalive).
332 * @param tc Notification context.
335 GMC_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
338 * Send BCK keepalive packets for a connection.
340 * @param cls Closure (connection for which to send the keepalive).
341 * @param tc Notification context.
344 GMC_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
348 * Notify other peers on a connection of a broken link. Mark connections
349 * to destroy after all traffic has been sent.
351 * @param c Connection on which there has been a disconnection.
352 * @param peer Peer that disconnected.
355 GMC_notify_broken (struct MeshConnection *c,
356 struct MeshPeer *peer);
359 * Is this peer the first one on the connection?
361 * @param c Connection.
362 * @param fwd Is this about fwd traffic?
364 * @return GNUNET_YES if origin, GNUNET_NO if relay/terminal.
367 GMC_is_origin (struct MeshConnection *c, int fwd);
370 * Is this peer the last one on the connection?
372 * @param c Connection.
373 * @param fwd Is this about fwd traffic?
374 * Note that the ROOT is the terminal for BCK traffic!
376 * @return GNUNET_YES if terminal, GNUNET_NO if relay/origin.
379 GMC_is_terminal (struct MeshConnection *c, int fwd);
382 * See if we are allowed to send by the next hop in the given direction.
384 * @param c Connection.
385 * @param fwd Is this about fwd traffic?
387 * @return GNUNET_YES in case it's OK.
390 GMC_is_sendable (struct MeshConnection *c, int fwd);
393 * Sends an already built message on a connection, properly registering
394 * all used resources.
396 * @param message Message to send. Function makes a copy of it.
397 * If message is not hop-by-hop, decrements TTL of copy.
398 * @param c Connection on which this message is transmitted.
399 * @param ch Channel on which this message is transmitted, or NULL.
400 * @param fwd Is this a fwd message?
403 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
404 struct MeshConnection *c,
405 struct MeshChannel *ch,
409 * Sends a CREATE CONNECTION message for a path to a peer.
410 * Changes the connection and tunnel states if necessary.
412 * @param connection Connection to create.
415 GMC_send_create (struct MeshConnection *connection);
418 * Send a message to all peers in this connection that the connection
419 * is no longer valid.
421 * If some peer should not receive the message, it should be zero'ed out
422 * before calling this function.
424 * @param c The connection whose peers to notify.
427 GMC_send_destroy (struct MeshConnection *c);
430 * @brief Start a polling timer for the connection.
432 * When a neighbor does not accept more traffic on the connection it could be
433 * caused by a simple congestion or by a lost ACK. Polling enables to check
434 * for the lastest ACK status for a connection.
436 * @param c Connection.
437 * @param fwd Should we poll in the FWD direction?
440 GMC_start_poll (struct MeshConnection *c, int fwd);
444 * @brief Stop polling a connection for ACKs.
446 * Once we have enough ACKs for future traffic, polls are no longer necessary.
448 * @param c Connection.
449 * @param fwd Should we stop the poll in the FWD direction?
452 GMC_stop_poll (struct MeshConnection *c, int fwd);
454 #if 0 /* keep Emacsens' auto-indent happy */
461 /* ifndef GNUNET_SERVICE_MESH_CONNECTION_H */
463 /* end of gnunet-service-mesh_connection.h */