2 This file is part of GNUnet.
3 Copyright (C) 2009-2017 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
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13 Affero General Public License for more details.
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16 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 * @author Christian Grothoff
23 * CADET service; establish channels to distant peers
25 * @defgroup cadet CADET service
26 * Confidential Ad-hoc Decentralized End-to-End Transport
28 * @see [Documentation](https://gnunet.org/cadet-subsystem)
29 * @see [Paper](https://gnunet.org/cadet)
33 #ifndef GNUNET_CADET_SERVICE_H
34 #define GNUNET_CADET_SERVICE_H
39 #if 0 /* keep Emacsens' auto-indent happy */
44 #include "gnunet_util_lib.h"
45 #include "gnunet_transport_service.h"
48 * Version number of GNUnet-cadet API.
50 #define GNUNET_CADET_VERSION 0x00000005
54 * Opaque handle to the service.
56 struct GNUNET_CADET_Handle;
59 * Opaque handle to a channel.
61 struct GNUNET_CADET_Channel;
64 * Opaque handle to a port.
66 struct GNUNET_CADET_Port;
70 * Hash uniquely identifying a connection below a tunnel.
72 struct GNUNET_CADET_ConnectionTunnelIdentifier
74 struct GNUNET_ShortHashCode connection_of_tunnel;
79 * Number identifying a CADET channel within a tunnel.
81 struct GNUNET_CADET_ChannelTunnelNumber
84 * Which number does this channel have that uniquely identfies
85 * it within its tunnel, in network byte order.
87 * Given two peers, both may initiate channels over the same tunnel.
88 * The @e cn must be greater or equal to 0x80000000 (high-bit set)
89 * for tunnels initiated with the peer that has the larger peer
90 * identity as compared using #GNUNET_CRYPTO_cmp_peer_identity().
92 uint32_t cn GNUNET_PACKED;
97 * Channel options. Second line indicates filed in the
98 * CadetChannelInfo union carrying the answer.
100 enum GNUNET_CADET_ChannelOption
103 * Default options: unreliable, default buffering, not out of order.
105 GNUNET_CADET_OPTION_DEFAULT = 0x0,
108 * Disable buffering on intermediate nodes (for minimum latency).
111 GNUNET_CADET_OPTION_NOBUFFER = 0x1,
114 * Enable channel reliability, lost messages will be retransmitted.
117 GNUNET_CADET_OPTION_RELIABLE = 0x2,
120 * Enable out of order delivery of messages.
121 * Set bit for out-of-order delivery.
123 GNUNET_CADET_OPTION_OUT_OF_ORDER = 0x4,
126 * Who is the peer at the other end of the channel.
127 * Only for use in @c GNUNET_CADET_channel_get_info
128 * struct GNUNET_PeerIdentity *peer
130 GNUNET_CADET_OPTION_PEER = 0x8
136 * Method called whenever a peer connects to a port in MQ-based CADET.
138 * @param cls Closure from #GNUNET_CADET_open_port.
139 * @param channel New handle to the channel.
140 * @param source Peer that started this channel.
141 * @return Closure for the incoming @a channel. It's given to:
142 * - The #GNUNET_CADET_DisconnectEventHandler (given to
143 * #GNUNET_CADET_open_port) when the channel dies.
144 * - Each the #GNUNET_MQ_MessageCallback handlers for each message
145 * received on the @a channel.
148 (*GNUNET_CADET_ConnectEventHandler) (void *cls,
149 struct GNUNET_CADET_Channel *channel,
150 const struct GNUNET_PeerIdentity *source);
154 * Function called whenever an MQ-channel is destroyed, unless the destruction
155 * was requested by #GNUNET_CADET_channel_destroy.
156 * It must NOT call #GNUNET_CADET_channel_destroy on the channel.
158 * It should clean up any associated state, including cancelling any pending
159 * transmission on this channel.
161 * @param cls Channel closure.
162 * @param channel Connection to the other end (henceforth invalid).
165 (*GNUNET_CADET_DisconnectEventHandler) (void *cls,
166 const struct GNUNET_CADET_Channel *channel);
170 * Function called whenever an MQ-channel's transmission window size changes.
172 * The first callback in an outgoing channel will be with a non-zero value
173 * and will mean the channel is connected to the destination.
175 * For an incoming channel it will be called immediately after the
176 * #GNUNET_CADET_ConnectEventHandler, also with a non-zero value.
178 * @param cls Channel closure.
179 * @param channel Connection to the other end --- FIXME: drop?
180 * @param window_size New window size. If the is more messages than buffer size
181 * this value will be negative. -- FIXME: make unsigned, we never call negative?
184 (*GNUNET_CADET_WindowSizeEventHandler) (void *cls,
185 const struct GNUNET_CADET_Channel *channel,
190 * Connect to the MQ-based cadet service.
192 * @param cfg Configuration to use.
193 * @return Handle to the cadet service NULL on error.
195 struct GNUNET_CADET_Handle *
196 GNUNET_CADET_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
200 * Disconnect from the cadet service. All channels will be destroyed. All channel
201 * disconnect callbacks will be called on any still connected peers, notifying
202 * about their disconnection. The registered inbound channel cleaner will be
203 * called should any inbound channels still exist.
205 * @param handle connection to cadet to disconnect
208 GNUNET_CADET_disconnect (struct GNUNET_CADET_Handle *handle);
212 * Open a port to receive incomming MQ-based channels.
214 * @param h CADET handle.
215 * @param port Hash identifying the port.
216 * @param connects Function called when an incoming channel is connected.
217 * @param connects_cls Closure for the @a connects handler.
218 * @param window_changes Function called when the transmit window size changes.
220 * @param disconnects Function called when a channel is disconnected.
221 * @param handlers Callbacks for messages we care about, NULL-terminated.
222 * @return Port handle, NULL if port is in use
224 struct GNUNET_CADET_Port *
225 GNUNET_CADET_open_port (struct GNUNET_CADET_Handle *h,
226 const struct GNUNET_HashCode *port,
227 GNUNET_CADET_ConnectEventHandler connects,
229 GNUNET_CADET_WindowSizeEventHandler window_changes,
230 GNUNET_CADET_DisconnectEventHandler disconnects,
231 const struct GNUNET_MQ_MessageHandler *handlers);
235 * Close a port opened with @a GNUNET_CADET_open_port.
236 * The @a new_channel callback will no longer be called.
238 * @param p Port handle.
241 GNUNET_CADET_close_port (struct GNUNET_CADET_Port *p);
245 * Create a new channel towards a remote peer.
247 * If the destination port is not open by any peer or the destination peer
248 * does not accept the channel, @a disconnects will be called
251 * @param h CADET handle.
252 * @param channel_cls Closure for the channel. It's given to:
253 * - The management handler @a window_changes.
254 * - The disconnect handler @a disconnects
255 * - Each message type callback in @a handlers
256 * @param destination Peer identity the channel should go to.
257 * @param port Identification of the destination port.
258 * @param options CadetOption flag field, with all desired option bits set to 1.
259 * @param window_changes Function called when the transmit window size changes.
260 * Can be NULL if this data is of no interest.
261 * TODO Not yet implemented.
262 * @param disconnects Function called when the channel is disconnected.
263 * @param handlers Callbacks for messages we care about, NULL-terminated.
264 * @return Handle to the channel.
266 struct GNUNET_CADET_Channel *
267 GNUNET_CADET_channel_create (struct GNUNET_CADET_Handle *h,
269 const struct GNUNET_PeerIdentity *destination,
270 const struct GNUNET_HashCode *port,
271 enum GNUNET_CADET_ChannelOption options,
272 GNUNET_CADET_WindowSizeEventHandler window_changes,
273 GNUNET_CADET_DisconnectEventHandler disconnects,
274 const struct GNUNET_MQ_MessageHandler *handlers);
278 * Destroy an existing channel.
280 * The existing end callback for the channel will NOT be called.
281 * Any pending outgoing messages will be sent but no incoming messages will be
282 * accepted and no data callbacks will be called.
284 * @param channel Channel handle, becomes invalid after this call.
287 GNUNET_CADET_channel_destroy (struct GNUNET_CADET_Channel *channel);
291 * Obtain the message queue for a connected channel.
293 * @param channel The channel handle from which to get the MQ.
294 * @return The message queue of the channel.
296 struct GNUNET_MQ_Handle *
297 GNUNET_CADET_get_mq (const struct GNUNET_CADET_Channel *channel);
301 * Indicate readiness to receive the next message on a channel.
303 * Should only be called once per handler called.
305 * @param channel Channel that will be allowed to call another handler.
308 GNUNET_CADET_receive_done (struct GNUNET_CADET_Channel *channel);
311 /******************************************************************************/
312 /******************** MONITORING /DEBUG API *************************/
313 /******************************************************************************/
314 /* The following calls are not useful for normal CADET operation, but for */
315 /* debug and monitoring of the cadet state. They can be safely ignored. */
316 /* The API can change at any point without notice. */
317 /* Please contact the developer if you consider any of this calls useful for */
318 /* normal cadet applications. */
319 /******************************************************************************/
323 * Transitional function to convert an unsigned int port to a hash value.
324 * WARNING: local static value returned, NOT reentrant!
325 * WARNING: do not use this function for new code!
327 * @param port Numerical port (unsigned int format).
329 * @return A GNUNET_HashCode usable for the new CADET API.
331 const struct GNUNET_HashCode *
332 GC_u2h (uint32_t port);
337 * Struct to retrieve info about a channel.
339 union GNUNET_CADET_ChannelInfo
343 * #GNUNET_YES / #GNUNET_NO, for binary flags.
348 * Peer on the other side of the channel
350 const struct GNUNET_PeerIdentity peer;
355 * Get information about a channel.
357 * @param channel Channel handle.
358 * @param option Query type GNUNET_CADET_OPTION_*
359 * @param ... dependant on option, currently not used
360 * @return Union with an answer to the query.
362 const union GNUNET_CADET_ChannelInfo *
363 GNUNET_CADET_channel_get_info (struct GNUNET_CADET_Channel *channel,
364 enum GNUNET_CADET_ChannelOption option,
369 * Method called to retrieve information about a specific channel the cadet peer
370 * is aware of, including all transit nodes.
372 * @param cls Closure.
373 * @param root Root of the channel.
374 * @param dest Destination of the channel.
375 * @param port Destination port of the channel.
376 * @param root_channel_number Local number for root, if known.
377 * @param dest_channel_number Local number for dest, if known.
378 * @param public_channel_numbe Number for P2P, always known.
381 (*GNUNET_CADET_ChannelCB) (void *cls,
382 const struct GNUNET_PeerIdentity *root,
383 const struct GNUNET_PeerIdentity *dest,
384 uint32_t /* UGH */ port,
385 uint32_t /* ugh */ root_channel_number,
386 uint32_t /* ugh */ dest_channel_number,
387 uint32_t /* ugh */ public_channel_number);
390 * Method called to retrieve information about all peers in CADET, called
393 * After last peer has been reported, an additional call with NULL is done.
395 * @param cls Closure.
396 * @param peer Peer, or NULL on "EOF".
397 * @param tunnel Do we have a tunnel towards this peer?
398 * @param n_paths Number of known paths towards this peer.
399 * @param best_path How long is the best path?
400 * (0 = unknown, 1 = ourselves, 2 = neighbor)
403 (*GNUNET_CADET_PeersCB) (void *cls,
404 const struct GNUNET_PeerIdentity *peer,
406 unsigned int n_paths,
407 unsigned int best_path);
410 * Method called to retrieve information about a specific peer
411 * known to the service.
413 * @param cls Closure.
414 * @param peer Peer ID.
415 * @param tunnel Do we have a tunnel towards this peer? #GNUNET_YES/#GNUNET_NO
416 * @param neighbor Is this a direct neighbor? #GNUNET_YES/#GNUNET_NO
417 * @param n_paths Number of paths known towards peer.
418 * @param paths Array of PEER_IDs representing all paths to reach the peer.
419 * Each path starts with the first hop (local peer not included).
420 * Each path ends with the destination peer (given in @c peer).
423 (*GNUNET_CADET_PeerCB) (void *cls,
424 const struct GNUNET_PeerIdentity *peer,
427 unsigned int n_paths,
428 const struct GNUNET_PeerIdentity *paths,
430 int finished_with_paths);
434 * Method called to retrieve information about all tunnels in CADET, called
437 * After last tunnel has been reported, an additional call with NULL is done.
439 * @param cls Closure.
440 * @param peer Destination peer, or NULL on "EOF".
441 * @param channels Number of channels.
442 * @param connections Number of connections.
443 * @param estate Encryption state.
444 * @param cstate Connectivity state.
447 (*GNUNET_CADET_TunnelsCB) (void *cls,
448 const struct GNUNET_PeerIdentity *peer,
449 unsigned int channels,
450 unsigned int connections,
456 * Method called to retrieve information about a specific tunnel the cadet peer
457 * has established, o`r is trying to establish.
459 * @param cls Closure.
460 * @param peer Peer towards whom the tunnel is directed.
461 * @param n_channels Number of channels.
462 * @param n_connections Number of connections.
463 * @param channels Channels.
464 * @param connections Connections.
465 * @param estate Encryption state.
466 * @param cstate Connectivity state.
469 (*GNUNET_CADET_TunnelCB) (void *cls,
470 const struct GNUNET_PeerIdentity *peer,
471 unsigned int n_channels,
472 unsigned int n_connections,
473 const struct GNUNET_CADET_ChannelTunnelNumber *channels,
474 const struct GNUNET_CADET_ConnectionTunnelIdentifier *connections,
476 unsigned int cstate);
480 * Request information about a specific channel of the running cadet peer.
482 * WARNING: unstable API, likely to change in the future!
484 * @param h Handle to the cadet peer.
485 * @param peer ID of the other end of the channel.
486 * @param channel_number Channel number.
487 * @param callback Function to call with the requested data.
488 * @param callback_cls Closure for @c callback.
491 GNUNET_CADET_get_channel (struct GNUNET_CADET_Handle *h,
492 struct GNUNET_PeerIdentity *peer,
493 uint32_t /* UGH */ channel_number,
494 GNUNET_CADET_ChannelCB callback,
499 * Request a debug dump on the service's STDERR.
501 * WARNING: unstable API, likely to change in the future!
503 * @param h cadet handle
506 GNUNET_CADET_request_dump (struct GNUNET_CADET_Handle *h);
510 * Request information about peers known to the running cadet service.
511 * The callback will be called for every peer known to the service.
512 * Only one info request (of any kind) can be active at once.
515 * WARNING: unstable API, likely to change in the future!
517 * @param h Handle to the cadet peer.
518 * @param callback Function to call with the requested data.
519 * @param callback_cls Closure for @c callback.
521 * @return #GNUNET_OK / #GNUNET_SYSERR
524 GNUNET_CADET_get_peers (struct GNUNET_CADET_Handle *h,
525 GNUNET_CADET_PeersCB callback,
530 * Cancel a peer info request. The callback will not be called (anymore).
532 * WARNING: unstable API, likely to change in the future!
534 * @param h Cadet handle.
536 * @return Closure that was given to #GNUNET_CADET_get_peers().
539 GNUNET_CADET_get_peers_cancel (struct GNUNET_CADET_Handle *h);
543 * Request information about a peer known to the running cadet peer.
544 * The callback will be called for the tunnel once.
545 * Only one info request (of any kind) can be active at once.
547 * WARNING: unstable API, likely to change in the future!
549 * @param h Handle to the cadet peer.
550 * @param id Peer whose tunnel to examine.
551 * @param callback Function to call with the requested data.
552 * @param callback_cls Closure for @c callback.
554 * @return #GNUNET_OK / #GNUNET_SYSERR
557 GNUNET_CADET_get_peer (struct GNUNET_CADET_Handle *h,
558 const struct GNUNET_PeerIdentity *id,
559 GNUNET_CADET_PeerCB callback,
564 * Request information about tunnels of the running cadet peer.
565 * The callback will be called for every tunnel of the service.
566 * Only one info request (of any kind) can be active at once.
568 * WARNING: unstable API, likely to change in the future!
570 * @param h Handle to the cadet peer.
571 * @param callback Function to call with the requested data.
572 * @param callback_cls Closure for @c callback.
574 * @return #GNUNET_OK / #GNUNET_SYSERR
577 GNUNET_CADET_get_tunnels (struct GNUNET_CADET_Handle *h,
578 GNUNET_CADET_TunnelsCB callback,
583 * Cancel a monitor request. The monitor callback will not be called.
585 * @param h Cadet handle.
587 * @return Closure given to #GNUNET_CADET_get_tunnels(), if any.
590 GNUNET_CADET_get_tunnels_cancel (struct GNUNET_CADET_Handle *h);
594 * Request information about a tunnel of the running cadet peer.
595 * The callback will be called for the tunnel once.
596 * Only one info request (of any kind) can be active at once.
598 * WARNING: unstable API, likely to change in the future!
600 * @param h Handle to the cadet peer.
601 * @param id Peer whose tunnel to examine.
602 * @param callback Function to call with the requested data.
603 * @param callback_cls Closure for @c callback.
605 * @return #GNUNET_OK / #GNUNET_SYSERR
608 GNUNET_CADET_get_tunnel (struct GNUNET_CADET_Handle *h,
609 const struct GNUNET_PeerIdentity *id,
610 GNUNET_CADET_TunnelCB callback,
615 #if 0 /* keep Emacsens' auto-indent happy */
622 /* ifndef GNUNET_CADET_SERVICE_H */
625 /** @} */ /* end of group */
627 /* end of gnunet_cadet_service.h */