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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.
62 enum GNUNET_MESH_ChannelOption
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.
149 * A call to #GNUNET_MESH_channel_destroy causes te channel to be ignored. In
150 * this case the handler MUST return NULL.
153 * @param channel new handle to the channel
154 * @param initiator peer that started the channel
155 * @param port Port this channel is for.
156 * @param options MeshOption flag field, with all active option bits set to 1.
158 * @return initial channel context for the channel
159 * (can be NULL -- that's not an error)
161 typedef void *(GNUNET_MESH_InboundChannelNotificationHandler) (void *cls,
169 enum GNUNET_MESH_ChannelOption
174 * Function called whenever a channel is destroyed. Should clean up
175 * any associated state.
177 * It must NOT call #GNUNET_MESH_channel_destroy on the channel.
179 * @param cls closure (set from #GNUNET_MESH_connect)
180 * @param channel connection to the other end (henceforth invalid)
181 * @param channel_ctx place where local state associated
182 * with the channel is stored
184 typedef void (GNUNET_MESH_ChannelEndHandler) (void *cls,
185 const struct GNUNET_MESH_Channel *
191 * Connect to the mesh service.
193 * @param cfg Configuration to use.
194 * @param cls Closure for the various callbacks that follow (including
195 * handlers in the handlers array).
196 * @param new_channel Function called when an *incoming* channel is created.
197 * Can be NULL if no inbound channels are desired.
199 * @param cleaner Function called when a channel is destroyed by the remote peer.
200 * It is NOT called if #GNUNET_MESH_channel_destroy is called on
202 * @param handlers Callbacks for messages we care about, NULL-terminated. Each
203 * one must call #GNUNET_MESH_receive_done on the channel to
204 * receive the next message. Messages of a type that is not
205 * in the handlers array are ignored if received.
206 * @param ports NULL or 0-terminated array of port numbers for incoming channels.
207 * See @a new_channel.
209 * @return handle to the mesh service NULL on error
210 * (in this case, init is never called)
212 struct GNUNET_MESH_Handle *
213 GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, void *cls,
214 GNUNET_MESH_InboundChannelNotificationHandler new_channel,
215 GNUNET_MESH_ChannelEndHandler cleaner,
216 const struct GNUNET_MESH_MessageHandler *handlers,
217 const uint32_t *ports);
221 * Disconnect from the mesh service. All channels will be destroyed. All channel
222 * disconnect callbacks will be called on any still connected peers, notifying
223 * about their disconnection. The registered inbound channel cleaner will be
224 * called should any inbound channels still exist.
226 * @param handle connection to mesh to disconnect
229 GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle);
233 * Create a new channel towards a remote peer.
235 * If the destination port is not open by any peer or the destination peer
236 * does not accept the channel, #GNUNET_MESH_ChannelEndHandler will be called
239 * @param h mesh handle
240 * @param channel_ctx client's channel context to associate with the channel
241 * @param peer peer identity the channel should go to
242 * @param port Port number.
243 * @param options MeshOption flag field, with all desired option bits set to 1.
245 * @return handle to the channel
247 struct GNUNET_MESH_Channel *
248 GNUNET_MESH_channel_create (struct GNUNET_MESH_Handle *h,
250 const struct GNUNET_PeerIdentity *peer,
252 enum GNUNET_MESH_ChannelOption options);
256 * Destroy an existing channel.
258 * The existing end callback for the channel will be called immediately.
259 * Any pending outgoing messages will be sent but no incoming messages will be
260 * accepted and no data callbacks will be called.
262 * @param channel Channel handle, becomes invalid after this call.
265 GNUNET_MESH_channel_destroy (struct GNUNET_MESH_Channel *channel);
269 * Struct to retrieve info about a channel.
271 union GNUNET_MESH_ChannelInfo
275 * #GNUNET_YES / #GNUNET_NO, for binary flags.
280 * Peer on the other side of the channel
282 const struct GNUNET_PeerIdentity peer;
287 * Get information about a channel.
289 * @param channel Channel handle.
290 * @param option Query type GNUNET_MESH_OPTION_*
291 * @param ... dependant on option, currently not used
292 * @return Union with an answer to the query.
294 const union GNUNET_MESH_ChannelInfo *
295 GNUNET_MESH_channel_get_info (struct GNUNET_MESH_Channel *channel,
296 enum GNUNET_MESH_ChannelOption option, ...);
300 * Handle for a transmission request.
302 struct GNUNET_MESH_TransmitHandle;
306 * Ask the mesh to call @a notify once it is ready to transmit the
307 * given number of bytes to the specified channel.
308 * Only one call can be active at any time, to issue another request,
309 * wait for the callback or cancel the current request.
311 * @param channel channel to use for transmission
312 * @param cork is corking allowed for this transmission?
313 * @param maxdelay how long can the message wait?
314 * @param notify_size how many bytes of buffer space does notify want?
315 * @param notify function to call when buffer space is available;
316 * will be called with NULL on timeout or if the overall queue
317 * for this peer is larger than queue_size and this is currently
318 * the message with the lowest priority
319 * @param notify_cls closure for @a notify
320 * @return non-NULL if the notify callback was queued,
321 * NULL if we can not even queue the request (insufficient
322 * memory); if NULL is returned, @a notify will NOT be called.
324 struct GNUNET_MESH_TransmitHandle *
325 GNUNET_MESH_notify_transmit_ready (struct GNUNET_MESH_Channel *channel,
327 struct GNUNET_TIME_Relative maxdelay,
329 GNUNET_CONNECTION_TransmitReadyNotify notify,
334 * Cancel the specified transmission-ready notification.
336 * @param th handle that was returned by "notify_transmit_ready".
339 GNUNET_MESH_notify_transmit_ready_cancel (struct GNUNET_MESH_TransmitHandle
344 * Indicate readiness to receive the next message on a channel.
346 * Should only be called once per handler called.
348 * @param channel Channel that will be allowed to call another handler.
351 GNUNET_MESH_receive_done (struct GNUNET_MESH_Channel *channel);
355 /******************************************************************************/
356 /******************** MONITORING /DEBUG API *************************/
357 /******************************************************************************/
358 /* The following calls are not useful for normal MESH operation, but for */
359 /* debug and monitoring of the mesh state. They can be safely ignored. */
360 /* The API can change at any point without notice. */
361 /* Please contact the developer if you consider any of this calls useful for */
362 /* normal mesh applications. */
363 /******************************************************************************/
366 * Method called to retrieve information about each channel the mesh peer
369 * @param cls Closure.
370 * @param channel_number Channel number.
371 * @param origin that started the channel (owner).
372 * @param target other endpoint of the channel
374 typedef void (*GNUNET_MESH_ChannelsCB) (void *cls,
375 uint32_t channel_number,
376 const struct GNUNET_PeerIdentity *origin,
377 const struct GNUNET_PeerIdentity *target);
381 * Method called to retrieve information about a specific channel the mesh peer
382 * is aware of, including all transit nodes.
384 * @param cls Closure.
385 * @param peer Peer in the channel's tree.
386 * @param parent Parent of the current peer. All 0 when peer is root.
388 typedef void (*GNUNET_MESH_ChannelCB) (void *cls,
389 const struct GNUNET_PeerIdentity *peer,
390 const struct GNUNET_PeerIdentity *parent);
394 * Request information about the running mesh peer.
395 * The callback will be called for every channel known to the service,
396 * listing all active peers that belong to the channel.
398 * If called again on the same handle, it will overwrite the previous
399 * callback and cls. To retrieve the cls, monitor_cancel must be
402 * WARNING: unstable API, likely to change in the future!
404 * @param h Handle to the mesh peer.
405 * @param callback Function to call with the requested data.
406 * @param callback_cls Closure for @c callback.
409 GNUNET_MESH_get_channels (struct GNUNET_MESH_Handle *h,
410 GNUNET_MESH_ChannelsCB callback,
415 * Request information about a specific channel of the running mesh peer.
417 * WARNING: unstable API, likely to change in the future!
419 * @param h Handle to the mesh peer.
420 * @param initiator ID of the owner of the channel.
421 * @param channel_number Channel number.
422 * @param callback Function to call with the requested data.
423 * @param callback_cls Closure for @c callback.
426 GNUNET_MESH_show_channel (struct GNUNET_MESH_Handle *h,
427 struct GNUNET_PeerIdentity *initiator,
428 uint32_t channel_number,
429 GNUNET_MESH_ChannelCB callback,
434 * Cancel a monitor request. The monitor callback will not be called.
436 * WARNING: unstable API, likely to change in the future!
438 * @param h Mesh handle.
440 * @return Closure given to GNUNET_MESH_monitor, if any.
443 GNUNET_MESH_get_channels_cancel (struct GNUNET_MESH_Handle *h);
447 * Create a message queue for a mesh channel.
448 * The message queue can only be used to transmit messages,
449 * not to receive them.
451 * @param channel the channel to create the message qeue for
452 * @return a message queue to messages over the channel
454 struct GNUNET_MQ_Handle *
455 GNUNET_MESH_mq_create (struct GNUNET_MESH_Channel *channel);
458 #if 0 /* keep Emacsens' auto-indent happy */
465 /* ifndef GNUNET_MESH_SERVICE_H */
467 /* end of gnunet_mesh_service.h */