2 This file is part of GNUnet.
3 (C) 2013 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
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 mesh network traffic going orig->dest.
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_fwd (void *cls, const struct GNUNET_PeerIdentity *peer,
150 const struct GNUNET_MessageHeader *message);
154 * Core handler for mesh network traffic going dest->orig.
156 * @param cls Closure (unused).
157 * @param message Message received.
158 * @param peer Peer who sent the message.
160 * @return GNUNET_OK to keep the connection open,
161 * GNUNET_SYSERR to close it (signal serious error)
164 GMC_handle_bck (void *cls, const struct GNUNET_PeerIdentity *peer,
165 const struct GNUNET_MessageHeader *message);
168 * Core handler for mesh network traffic point-to-point acks.
171 * @param message message
172 * @param peer peer identity this notification is about
174 * @return GNUNET_OK to keep the connection open,
175 * GNUNET_SYSERR to close it (signal serious error)
178 GMC_handle_ack (void *cls, const struct GNUNET_PeerIdentity *peer,
179 const struct GNUNET_MessageHeader *message);
182 * Core handler for mesh network traffic point-to-point ack polls.
185 * @param message message
186 * @param peer peer identity this notification is about
188 * @return GNUNET_OK to keep the connection open,
189 * GNUNET_SYSERR to close it (signal serious error)
192 GMC_handle_poll (void *cls, const struct GNUNET_PeerIdentity *peer,
193 const struct GNUNET_MessageHeader *message);
196 * Core handler for mesh keepalives.
199 * @param message message
200 * @param peer peer identity this notification is about
201 * @return GNUNET_OK to keep the connection open,
202 * GNUNET_SYSERR to close it (signal serious error)
204 * TODO: Check who we got this from, to validate route.
207 GMC_handle_keepalive (void *cls, const struct GNUNET_PeerIdentity *peer,
208 const struct GNUNET_MessageHeader *message);
211 * Send an ACK on the appropriate connection/channel, depending on
212 * the direction and the position of the peer.
214 * @param c Which connection to send the hop-by-hop ACK.
215 * @param ch Channel, if any.
216 * @param fwd Is this a fwd ACK? (will go dest->root)
219 GMC_send_ack (struct MeshConnection *c, struct MeshChannel *ch, int fwd);
222 * Initialize the connections subsystem
224 * @param c Configuration handle.
227 GMC_init (const struct GNUNET_CONFIGURATION_Handle *c);
230 * Shut down the connections subsystem.
236 * Create a connection.
238 * @param cid Connection ID (either created locally or imposed remotely).
239 * @param t Tunnel this connection belongs to (or NULL);
240 * @param p Path this connection has to use.
241 * @param own_pos Own position in the @c p 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 and remove from tunnel.
252 * @param c Connection to destroy.
255 GMC_destroy (struct MeshConnection *c);
258 * Get the connection ID.
260 * @param c Connection to get the ID from.
262 * @return ID of the connection.
264 const struct GNUNET_HashCode *
265 GMC_get_id (const struct MeshConnection *c);
268 * Get the connection path.
270 * @param c Connection to get the path from.
272 * @return path used by the connection.
274 const struct MeshPeerPath *
275 GMC_get_path (const struct MeshConnection *c);
278 * Get the connection state.
280 * @param c Connection to get the state from.
282 * @return state of the connection.
284 enum MeshConnectionState
285 GMC_get_state (const struct MeshConnection *c);
288 * Get the connection tunnel.
290 * @param c Connection to get the tunnel from.
292 * @return tunnel of the connection.
295 GMC_get_tunnel (const struct MeshConnection *c);
298 * Get free buffer space in a connection.
300 * @param c Connection.
301 * @param fwd Is query about FWD traffic?
303 * @return Free buffer space [0 - max_msgs_queue/max_connections]
306 GMC_get_buffer (struct MeshConnection *c, int fwd);
309 * Get how many messages have we allowed to send to us from a direction..
311 * @param c Connection.
312 * @param fwd Are we asking about traffic from FWD (BCK messages)?
314 * @return last_ack_sent - last_pid_recv
317 GMC_get_allowed (struct MeshConnection *c, int fwd);
320 * Get messages queued in a connection.
322 * @param c Connection.
323 * @param fwd Is query about FWD traffic?
325 * @return Number of messages queued.
328 GMC_get_qn (struct MeshConnection *c, int fwd);
331 * Allow the connection to advertise a buffer of the given size.
333 * The connection will send an @c fwd ACK message (so: in direction !fwd)
334 * allowing up to last_pid_recv + buffer.
336 * @param c Connection.
337 * @param buffer How many more messages the connection can accept.
338 * @param fwd Is this about FWD traffic? (The ack will go dest->root).
341 GMC_allow (struct MeshConnection *c, unsigned int buffer, int fwd);
344 * Send FWD keepalive packets for a connection.
346 * @param cls Closure (connection for which to send the keepalive).
347 * @param tc Notification context.
350 GMC_fwd_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
353 * Send BCK keepalive packets for a connection.
355 * @param cls Closure (connection for which to send the keepalive).
356 * @param tc Notification context.
359 GMC_bck_keepalive (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
363 * Notify other peers on a connection of a broken link. Mark connections
364 * to destroy after all traffic has been sent.
366 * @param c Connection on which there has been a disconnection.
367 * @param peer Peer that disconnected.
370 GMC_notify_broken (struct MeshConnection *c,
371 struct MeshPeer *peer);
374 * Is this peer the first one on the connection?
376 * @param c Connection.
377 * @param fwd Is this about fwd traffic?
379 * @return GNUNET_YES if origin, GNUNET_NO if relay/terminal.
382 GMC_is_origin (struct MeshConnection *c, int fwd);
385 * Is this peer the last one on the connection?
387 * @param c Connection.
388 * @param fwd Is this about fwd traffic?
389 * Note that the ROOT is the terminal for BCK traffic!
391 * @return GNUNET_YES if terminal, GNUNET_NO if relay/origin.
394 GMC_is_terminal (struct MeshConnection *c, int fwd);
397 * See if we are allowed to send by the next hop in the given direction.
399 * @param c Connection.
400 * @param fwd Is this about fwd traffic?
402 * @return GNUNET_YES in case it's OK.
405 GMC_is_sendable (struct MeshConnection *c, int fwd);
408 * Sends an already built message on a connection, properly registering
409 * all used resources.
411 * @param message Message to send. Function makes a copy of it.
412 * If message is not hop-by-hop, decrements TTL of copy.
413 * @param c Connection on which this message is transmitted.
414 * @param ch Channel on which this message is transmitted, or NULL.
415 * @param fwd Is this a fwd message?
418 GMC_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
419 struct MeshConnection *c,
420 struct MeshChannel *ch,
424 * Sends a CREATE CONNECTION message for a path to a peer.
425 * Changes the connection and tunnel states if necessary.
427 * @param connection Connection to create.
430 GMC_send_create (struct MeshConnection *connection);
433 * Send a message to all peers in this connection that the connection
434 * is no longer valid.
436 * If some peer should not receive the message, it should be zero'ed out
437 * before calling this function.
439 * @param c The connection whose peers to notify.
442 GMC_send_destroy (struct MeshConnection *c);
445 * @brief Start a polling timer for the connection.
447 * When a neighbor does not accept more traffic on the connection it could be
448 * caused by a simple congestion or by a lost ACK. Polling enables to check
449 * for the lastest ACK status for a connection.
451 * @param c Connection.
452 * @param fwd Should we poll in the FWD direction?
455 GMC_start_poll (struct MeshConnection *c, int fwd);
459 * @brief Stop polling a connection for ACKs.
461 * Once we have enough ACKs for future traffic, polls are no longer necessary.
463 * @param c Connection.
464 * @param fwd Should we stop the poll in the FWD direction?
467 GMC_stop_poll (struct MeshConnection *c, int fwd);
469 #if 0 /* keep Emacsens' auto-indent happy */
476 /* ifndef GNUNET_SERVICE_MESH_CONNECTION_H */
478 /* end of gnunet-service-mesh_connection.h */