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3 (C) 2009 - 2013 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_mesh_service.h
23 * @brief mesh service; establish channels to distant peers
24 * @author Christian Grothoff
27 #ifndef GNUNET_MESH_SERVICE_H
28 #define GNUNET_MESH_SERVICE_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_util_lib.h"
39 #include "gnunet_transport_service.h"
42 * Version number of GNUnet-mesh API.
44 #define GNUNET_MESH_VERSION 0x00000003
48 * Opaque handle to the service.
50 struct GNUNET_MESH_Handle;
53 * Opaque handle to a channel.
55 struct GNUNET_MESH_Channel;
60 * Second line indicates filed in the MeshChannelInfo union carrying the answer.
65 * Default options: unreliable, default buffering, not out of order.
67 GNUNET_MESH_OPTION_DEFAULT = 0x0,
70 * Disable buffering on intermediate nodes (for minimum latency).
73 GNUNET_MESH_OPTION_NOBUFFER = 0x1,
76 * Enable channel reliability, lost messages will be retransmitted.
79 GNUNET_MESH_OPTION_RELIABLE = 0x2,
82 * Enable out of order delivery of messages.
85 GNUNET_MESH_OPTION_OOORDER = 0x4,
88 * Who is the peer at the other end of the channel.
89 * Only for use in @c GNUNET_MESH_channel_get_info
90 * struct GNUNET_PeerIdentity *peer
92 GNUNET_MESH_OPTION_PEER = 0x8
98 * Functions with this signature are called whenever a message is
101 * Each time the function must call #GNUNET_MESH_receive_done on the channel
102 * in order to receive the next message. This doesn't need to be immediate:
103 * can be delayed if some processing is done on the message.
105 * @param cls Closure (set from #GNUNET_MESH_connect).
106 * @param channel Connection to the other end.
107 * @param channel_ctx Place to store local state associated with the channel.
108 * @param message The actual message.
109 * @return #GNUNET_OK to keep the channel open,
110 * #GNUNET_SYSERR to close it (signal serious error).
112 typedef int (*GNUNET_MESH_MessageCallback) (void *cls,
113 struct GNUNET_MESH_Channel *channel,
115 const struct GNUNET_MessageHeader *message);
119 * Message handler. Each struct specifies how to handle on particular
120 * type of message received.
122 struct GNUNET_MESH_MessageHandler
125 * Function to call for messages of "type".
127 GNUNET_MESH_MessageCallback callback;
130 * Type of the message this handler covers.
135 * Expected size of messages of this type. Use 0 for variable-size.
136 * If non-zero, messages of the given type will be discarded if they
137 * do not have the right size.
139 uint16_t expected_size;
144 * Method called whenever another peer has added us to a channel
145 * the other peer initiated.
146 * Only called (once) upon reception of data with a message type which was
147 * subscribed to in #GNUNET_MESH_connect. A call to #GNUNET_MESH_channel_destroy
148 * causes te channel to be ignored and no further notifications are sent about
152 * @param channel new handle to the channel
153 * @param initiator peer that started the channel
154 * @param port Port this channel is for.
155 * @param options MeshOption flag field, with all active option bits set to 1.
157 * @return initial channel context for the channel
158 * (can be NULL -- that's not an error)
160 typedef void *(GNUNET_MESH_InboundChannelNotificationHandler) (void *cls,
173 * Function called whenever a channel is destroyed. Should clean up
174 * any associated state.
176 * It must NOT call #GNUNET_MESH_channel_destroy on the channel.
178 * @param cls closure (set from #GNUNET_MESH_connect)
179 * @param channel connection to the other end (henceforth invalid)
180 * @param channel_ctx place where local state associated
181 * with the channel is stored
183 typedef void (GNUNET_MESH_ChannelEndHandler) (void *cls,
184 const struct GNUNET_MESH_Channel *
190 * Connect to the mesh service.
192 * @param cfg Configuration to use.
193 * @param cls Closure for the various callbacks that follow (including
194 * handlers in the handlers array).
195 * @param new_channel Function called when an *incoming* channel is created.
196 * Can be NULL if no inbound channels are desired.
198 * @param cleaner Function called when a channel is destroyed by the remote peer.
199 * It is NOT called if #GNUNET_MESH_channel_destroy is called on
201 * @param handlers Callbacks for messages we care about, NULL-terminated. Each
202 * one must call #GNUNET_MESH_receive_done on the channel to
203 * receive the next message. Messages of a type that is not
204 * in the handlers array are ignored if received.
205 * @param ports NULL or 0-terminated array of port numbers for incoming channels.
206 * See @a new_channel.
208 * @return handle to the mesh service NULL on error
209 * (in this case, init is never called)
211 struct GNUNET_MESH_Handle *
212 GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, void *cls,
213 GNUNET_MESH_InboundChannelNotificationHandler new_channel,
214 GNUNET_MESH_ChannelEndHandler cleaner,
215 const struct GNUNET_MESH_MessageHandler *handlers,
216 const uint32_t *ports);
220 * Disconnect from the mesh service. All channels will be destroyed. All channel
221 * disconnect callbacks will be called on any still connected peers, notifying
222 * about their disconnection. The registered inbound channel cleaner will be
223 * called should any inbound channels still exist.
225 * @param handle connection to mesh to disconnect
228 GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle);
232 * Create a new channel towards a remote peer.
234 * If the destination port is not open by any peer or the destination peer
235 * does not accept the channel, #GNUNET_MESH_ChannelEndHandler will be called
238 * @param h mesh handle
239 * @param channel_ctx client's channel context to associate with the channel
240 * @param peer peer identity the channel should go to
241 * @param port Port number.
242 * @param options MeshOption flag field, with all desired option bits set to 1.
244 * @return handle to the channel
246 struct GNUNET_MESH_Channel *
247 GNUNET_MESH_channel_create (struct GNUNET_MESH_Handle *h,
249 const struct GNUNET_PeerIdentity *peer,
251 enum MeshOption options);
255 * Destroy an existing channel.
257 * The existing end callback for the channel will be called immediately.
258 * Any pending outgoing messages will be sent but no incoming messages will be
259 * accepted and no data callbacks will be called.
261 * @param channel Channel handle, becomes invalid after this call.
264 GNUNET_MESH_channel_destroy (struct GNUNET_MESH_Channel *channel);
268 * Struct to retrieve info about a channel.
270 union GNUNET_MESH_ChannelInfo
274 * #GNUNET_YES / #GNUNET_NO, for binary flags.
279 * Peer on the other side of the channel
281 const struct GNUNET_PeerIdentity peer;
286 * Get information about a channel.
288 * @param channel Channel handle.
289 * @param option Query type GNUNET_MESH_OPTION_*
290 * @param ... dependant on option, currently not used
291 * @return Union with an answer to the query.
293 const union GNUNET_MESH_ChannelInfo *
294 GNUNET_MESH_channel_get_info (struct GNUNET_MESH_Channel *channel,
295 enum MeshOption option, ...);
299 * Handle for a transmission request.
301 struct GNUNET_MESH_TransmitHandle;
305 * Ask the mesh to call @a notify once it is ready to transmit the
306 * given number of bytes to the specified channel.
307 * Only one call can be active at any time, to issue another request,
308 * wait for the callback or cancel the current request.
310 * @param channel channel to use for transmission
311 * @param cork is corking allowed for this transmission?
312 * @param maxdelay how long can the message wait?
313 * @param notify_size how many bytes of buffer space does notify want?
314 * @param notify function to call when buffer space is available;
315 * will be called with NULL on timeout or if the overall queue
316 * for this peer is larger than queue_size and this is currently
317 * the message with the lowest priority
318 * @param notify_cls closure for @a notify
319 * @return non-NULL if the notify callback was queued,
320 * NULL if we can not even queue the request (insufficient
321 * memory); if NULL is returned, @a notify will NOT be called.
323 struct GNUNET_MESH_TransmitHandle *
324 GNUNET_MESH_notify_transmit_ready (struct GNUNET_MESH_Channel *channel,
326 struct GNUNET_TIME_Relative maxdelay,
328 GNUNET_CONNECTION_TransmitReadyNotify notify,
333 * Cancel the specified transmission-ready notification.
335 * @param th handle that was returned by "notify_transmit_ready".
338 GNUNET_MESH_notify_transmit_ready_cancel (struct GNUNET_MESH_TransmitHandle
343 * Indicate readiness to receive the next message on a channel.
345 * Should only be called once per handler called.
347 * @param channel Channel that will be allowed to call another handler.
350 GNUNET_MESH_receive_done (struct GNUNET_MESH_Channel *channel);
354 /******************************************************************************/
355 /******************** MONITORING /DEBUG API *************************/
356 /******************************************************************************/
357 /* The following calls are not useful for normal MESH operation, but for */
358 /* debug and monitoring of the mesh state. They can be safely ignored. */
359 /* The API can change at any point without notice. */
360 /* Please contact the developer if you consider any of this calls useful for */
361 /* normal mesh applications. */
362 /******************************************************************************/
365 * Method called to retrieve information about each channel the mesh peer
368 * @param cls Closure.
369 * @param channel_number Channel number.
370 * @param origin that started the channel (owner).
371 * @param target other endpoint of the channel
373 typedef void (*GNUNET_MESH_ChannelsCB) (void *cls,
374 uint32_t channel_number,
375 const struct GNUNET_PeerIdentity *origin,
376 const struct GNUNET_PeerIdentity *target);
380 * Method called to retrieve information about a specific channel the mesh peer
381 * is aware of, including all transit nodes.
383 * @param cls Closure.
384 * @param peer Peer in the channel's tree.
385 * @param parent Parent of the current peer. All 0 when peer is root.
387 typedef void (*GNUNET_MESH_ChannelCB) (void *cls,
388 const struct GNUNET_PeerIdentity *peer,
389 const struct GNUNET_PeerIdentity *parent);
393 * Request information about the running mesh peer.
394 * The callback will be called for every channel known to the service,
395 * listing all active peers that belong to the channel.
397 * If called again on the same handle, it will overwrite the previous
398 * callback and cls. To retrieve the cls, monitor_cancel must be
401 * WARNING: unstable API, likely to change in the future!
403 * @param h Handle to the mesh peer.
404 * @param callback Function to call with the requested data.
405 * @param callback_cls Closure for @c callback.
408 GNUNET_MESH_get_channels (struct GNUNET_MESH_Handle *h,
409 GNUNET_MESH_ChannelsCB callback,
414 * Request information about a specific channel of the running mesh peer.
416 * WARNING: unstable API, likely to change in the future!
418 * @param h Handle to the mesh peer.
419 * @param initiator ID of the owner of the channel.
420 * @param channel_number Channel number.
421 * @param callback Function to call with the requested data.
422 * @param callback_cls Closure for @c callback.
425 GNUNET_MESH_show_channel (struct GNUNET_MESH_Handle *h,
426 struct GNUNET_PeerIdentity *initiator,
427 uint32_t channel_number,
428 GNUNET_MESH_ChannelCB callback,
433 * Cancel a monitor request. The monitor callback will not be called.
435 * WARNING: unstable API, likely to change in the future!
437 * @param h Mesh handle.
439 * @return Closure given to GNUNET_MESH_monitor, if any.
442 GNUNET_MESH_get_channels_cancel (struct GNUNET_MESH_Handle *h);
446 * Create a message queue for a mesh channel.
447 * The message queue can only be used to transmit messages,
448 * not to receive them.
450 * @param channel the channel to create the message qeue for
451 * @return a message queue to messages over the channel
453 struct GNUNET_MQ_Handle *
454 GNUNET_MESH_mq_create (struct GNUNET_MESH_Channel *channel);
457 #if 0 /* keep Emacsens' auto-indent happy */
464 /* ifndef GNUNET_MESH_SERVICE_H */
466 /* end of gnunet_mesh_service.h */