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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 key exchange traffic (ephemeral key, ping, pong).
155 * @param cls Closure (unused).
156 * @param message Message received.
157 * @param peer Peer who sent the message.
159 * @return GNUNET_OK to keep the connection open,
160 * GNUNET_SYSERR to close it (signal serious error)
163 GMC_handle_kx (void *cls, const struct GNUNET_PeerIdentity *peer,
164 const struct GNUNET_MessageHeader *message);
167 * Core handler for mesh network traffic point-to-point acks.
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_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
178 const struct GNUNET_MessageHeader *message);
181 * Core handler for mesh network traffic point-to-point ack polls.
184 * @param message message
185 * @param peer peer identity this notification is about
187 * @return GNUNET_OK to keep the connection open,
188 * GNUNET_SYSERR to close it (signal serious error)
191 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
192 const struct GNUNET_MessageHeader *message);
195 * Core handler for mesh keepalives.
198 * @param message message
199 * @param peer peer identity this notification is about
200 * @return GNUNET_OK to keep the connection open,
201 * GNUNET_SYSERR to close it (signal serious error)
203 * TODO: Check who we got this from, to validate route.
206 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
207 const struct GNUNET_MessageHeader *message);
210 * Send an ACK on the appropriate connection/channel, depending on
211 * the direction and the position of the peer.
213 * @param c Which connection to send the hop-by-hop ACK.
214 * @param fwd Is this a fwd ACK? (will go dest->root)
217 GMC_send_ack (struct MeshConnection *c, int fwd);
220 * Initialize the connections subsystem
222 * @param c Configuration handle.
225 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c);
228 * Shut down the connections subsystem.
234 * Create a connection.
236 * @param cid Connection ID (either created locally or imposed remotely).
237 * @param t Tunnel this connection belongs to (or NULL);
238 * @param p Path this connection has to use.
239 * @param own_pos Own position in the @c p path.
241 * @return Newly created connection, NULL in case of error (own id not in path).
243 struct MeshConnection *
244 GMC_new (const struct GNUNET_HashCode *cid,
245 struct MeshTunnel3 *t,
246 struct MeshPeerPath *p,
247 unsigned int own_pos);
250 * Connection is no longer needed: destroy it.
252 * Cancels all pending traffic (including possible DESTROY messages), all
253 * maintenance tasks and removes the connection from neighbor peers and tunnel.
255 * @param c Connection to destroy.
258 GMC_destroy (struct MeshConnection *c);
261 * Get the connection ID.
263 * @param c Connection to get the ID from.
265 * @return ID of the connection.
267 const struct GNUNET_HashCode *
268 GMC_get_id (const struct MeshConnection *c);
271 * Get the connection path.
273 * @param c Connection to get the path from.
275 * @return path used by the connection.
277 const struct MeshPeerPath *
278 GMC_get_path (const struct MeshConnection *c);
281 * Get the connection state.
283 * @param c Connection to get the state from.
285 * @return state of the connection.
287 enum MeshConnectionState
288 GMC_get_state (const struct MeshConnection *c);
291 * Get the connection tunnel.
293 * @param c Connection to get the tunnel from.
295 * @return tunnel of the connection.
298 GMC_get_tunnel (const struct MeshConnection *c);
301 * Get free buffer space in a connection.
303 * @param c Connection.
304 * @param fwd Is query about FWD traffic?
306 * @return Free buffer space [0 - max_msgs_queue/max_connections]
309 GMC_get_buffer (struct MeshConnection *c, int fwd);
312 * Get how many messages have we allowed to send to us from a direction.
314 * @param c Connection.
315 * @param fwd Are we asking about traffic from FWD (BCK messages)?
317 * @return last_ack_sent - last_pid_recv
320 GMC_get_allowed (struct MeshConnection *c, int fwd);
323 * Get messages queued in a connection.
325 * @param c Connection.
326 * @param fwd Is query about FWD traffic?
328 * @return Number of messages queued.
331 GMC_get_qn (struct MeshConnection *c, int fwd);
334 * Allow the connection to advertise a buffer of the given size.
336 * The connection will send an @c fwd ACK message (so: in direction !fwd)
337 * allowing up to last_pid_recv + buffer.
339 * @param c Connection.
340 * @param buffer How many more messages the connection can accept.
341 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
344 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd);
347 * Send FWD keepalive packets for a connection.
349 * @param cls Closure (connection for which to send the keepalive).
350 * @param tc Notification context.
353 GMC_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
356 * Send BCK keepalive packets for a connection.
358 * @param cls Closure (connection for which to send the keepalive).
359 * @param tc Notification context.
362 GMC_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
366 * Notify other peers on a connection of a broken link. Mark connections
367 * to destroy after all traffic has been sent.
369 * @param c Connection on which there has been a disconnection.
370 * @param peer Peer that disconnected.
373 GMC_notify_broken (struct MeshConnection *c,
374 struct MeshPeer *peer);
377 * Is this peer the first one on the connection?
379 * @param c Connection.
380 * @param fwd Is this about fwd traffic?
382 * @return #GNUNET_YES if origin, #GNUNET_NO if relay/terminal.
385 GMC_is_origin (struct MeshConnection *c, int fwd);
388 * Is this peer the last one on the connection?
390 * @param c Connection.
391 * @param fwd Is this about fwd traffic?
392 * Note that the ROOT is the terminal for BCK traffic!
394 * @return #GNUNET_YES if terminal, #GNUNET_NO if relay/origin.
397 GMC_is_terminal (struct MeshConnection *c, int fwd);
400 * See if we are allowed to send by the next hop in the given direction.
402 * @param c Connection.
403 * @param fwd Is this about fwd traffic?
405 * @return #GNUNET_YES in case it's OK to send.
408 GMC_is_sendable (struct MeshConnection *c, int fwd);
411 * Sends an already built message on a connection, properly registering
412 * all used resources.
414 * @param message Message to send. Function makes a copy of it.
415 * If message is not hop-by-hop, decrements TTL of copy.
416 * @param c Connection on which this message is transmitted.
417 * @param fwd Is this a fwd message?
420 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
421 struct MeshConnection *c,
425 * Sends a CREATE CONNECTION message for a path to a peer.
426 * Changes the connection and tunnel states if necessary.
428 * @param connection Connection to create.
431 GMC_send_create (struct MeshConnection *connection);
434 * Send a message to all peers in this connection that the connection
435 * is no longer valid.
437 * If some peer should not receive the message, it should be zero'ed out
438 * before calling this function.
440 * @param c The connection whose peers to notify.
443 GMC_send_destroy (struct MeshConnection *c);
446 * @brief Start a polling timer for the connection.
448 * When a neighbor does not accept more traffic on the connection it could be
449 * caused by a simple congestion or by a lost ACK. Polling enables to check
450 * for the lastest ACK status for a connection.
452 * @param c Connection.
453 * @param fwd Should we poll in the FWD direction?
456 GMC_start_poll (struct MeshConnection *c, int fwd);
460 * @brief Stop polling a connection for ACKs.
462 * Once we have enough ACKs for future traffic, polls are no longer necessary.
464 * @param c Connection.
465 * @param fwd Should we stop the poll in the FWD direction?
468 GMC_stop_poll (struct MeshConnection *c, int fwd);
471 * Get a (static) string for a connection.
473 * @param c Connection.
476 GMC_2s (struct MeshConnection *c);
478 #if 0 /* keep Emacsens' auto-indent happy */
485 /* ifndef GNUNET_SERVICE_MESH_CONNECTION_H */
487 /* end of gnunet-service-mesh_connection.h */