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3 (C) 2009, 2010, 2011, 2012, 2013 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_mesh_service.h
23 * @brief mesh service; establish tunnels to distant peers
24 * @author Christian Grothoff
27 * - need to do sanity check that this is consistent
28 * with current ideas for the multicast layer's needs
31 #ifndef GNUNET_MESH_SERVICE_H
32 #define GNUNET_MESH_SERVICE_H
37 #if 0 /* keep Emacsens' auto-indent happy */
42 #include "gnunet_util_lib.h"
43 #include "gnunet_transport_service.h"
46 * Version number of GNUnet-mesh API.
48 #define GNUNET_MESH_VERSION 0x00000002
52 * Opaque handle to the service.
54 struct GNUNET_MESH_Handle;
57 * Opaque handle to a tunnel.
59 struct GNUNET_MESH_Tunnel;
63 * Options for querying a tunnel.
64 * Second line indicates filed in the MeshTunnelInfo union carrying the answer.
69 * Disable buffering on intermediate nodes (for minimum latency).
72 GNUNET_MESH_OPTION_NOBUFFER = 0x1,
75 * Enable tunnel reliability, lost messages will be retransmitted.
78 GNUNET_MESH_OPTION_RELIABLE = 0x2,
81 * Enable out of order delivery of messages.
84 GNUNET_MESH_OPTION_OOORDER = 0x4,
87 * Who is the peer at the other end of the tunnel.
88 * struct GNUNET_PeerIdentity *peer
90 GNUNET_MESH_OPTION_PEER = 0x8
96 * Functions with this signature are called whenever a message is
99 * Each time the function must call #GNUNET_MESH_receive_done on the tunnel
100 * in order to receive the next message. This doesn't need to be immediate:
101 * can be delayed if some processing is done on the message.
103 * @param cls Closure (set from #GNUNET_MESH_connect).
104 * @param tunnel Connection to the other end.
105 * @param tunnel_ctx Place to store local state associated with the tunnel.
106 * @param message The actual message.
108 * @return #GNUNET_OK to keep the tunnel open,
109 * #GNUNET_SYSERR to close it (signal serious error).
111 typedef int (*GNUNET_MESH_MessageCallback) (void *cls,
112 struct GNUNET_MESH_Tunnel *tunnel,
114 const struct GNUNET_MessageHeader *message);
118 * Message handler. Each struct specifies how to handle on particular
119 * type of message received.
121 struct GNUNET_MESH_MessageHandler
124 * Function to call for messages of "type".
126 GNUNET_MESH_MessageCallback callback;
129 * Type of the message this handler covers.
134 * Expected size of messages of this type. Use 0 for variable-size.
135 * If non-zero, messages of the given type will be discarded if they
136 * do not have the right size.
138 uint16_t expected_size;
143 * Method called whenever another peer has added us to a tunnel
144 * the other peer initiated.
145 * Only called (once) upon reception of data with a message type which was
146 * subscribed to in #GNUNET_MESH_connect. A call to #GNUNET_MESH_tunnel_destroy
147 * causes te tunnel to be ignored and no further notifications are sent about
151 * @param tunnel new handle to the tunnel
152 * @param initiator peer that started the tunnel
153 * @param port Port this tunnel is for.
154 * @return initial tunnel context for the tunnel
155 * (can be NULL -- that's not an error)
157 typedef void *(GNUNET_MESH_InboundTunnelNotificationHandler) (void *cls,
158 struct GNUNET_MESH_Tunnel *tunnel,
166 * Function called whenever a tunnel is destroyed. Should clean up
167 * any associated state.
169 * It must NOT call #GNUNET_MESH_tunnel_destroy on the tunnel.
171 * @param cls closure (set from #GNUNET_MESH_connect)
172 * @param tunnel connection to the other end (henceforth invalid)
173 * @param tunnel_ctx place where local state associated
174 * with the tunnel is stored
176 typedef void (GNUNET_MESH_TunnelEndHandler) (void *cls,
177 const struct GNUNET_MESH_Tunnel *
178 tunnel, void *tunnel_ctx);
182 * Connect to the mesh service.
184 * @param cfg Configuration to use.
185 * @param cls Closure for the various callbacks that follow (including
186 * handlers in the handlers array).
187 * @param new_tunnel Function called when an *incoming* tunnel is created.
188 * Can be NULL if no inbound tunnels are desired.
190 * @param cleaner Function called when a tunnel is destroyed by the remote peer.
191 * It is NOT called if #GNUNET_MESH_tunnel_destroy is called on
193 * @param handlers Callbacks for messages we care about, NULL-terminated. Each
194 * one must call #GNUNET_MESH_receive_done on the tunnel to
195 * receive the next message. Messages of a type that is not
196 * in the handlers array are ignored if received.
197 * @param ports NULL or 0-terminated array of port numbers for incoming tunnels.
200 * @return handle to the mesh service NULL on error
201 * (in this case, init is never called)
203 struct GNUNET_MESH_Handle *
204 GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
206 GNUNET_MESH_InboundTunnelNotificationHandler new_tunnel,
207 GNUNET_MESH_TunnelEndHandler cleaner,
208 const struct GNUNET_MESH_MessageHandler *handlers,
209 const uint32_t *ports);
213 * Disconnect from the mesh service. All tunnels will be destroyed. All tunnel
214 * disconnect callbacks will be called on any still connected peers, notifying
215 * about their disconnection. The registered inbound tunnel cleaner will be
216 * called should any inbound tunnels still exist.
218 * @param handle connection to mesh to disconnect
221 GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle);
225 * Create a new tunnel (we're initiator and will be allowed to add/remove peers
228 * @param h mesh handle
229 * @param tunnel_ctx client's tunnel context to associate with the tunnel
230 * @param peer peer identity the tunnel should go to
231 * @param port Port number.
232 * @param nobuffer Flag for disabling buffering on relay nodes.
233 * @param reliable Flag for end-to-end reliability.
234 * @return handle to the tunnel
236 struct GNUNET_MESH_Tunnel *
237 GNUNET_MESH_tunnel_create (struct GNUNET_MESH_Handle *h,
239 const struct GNUNET_PeerIdentity *peer,
246 * Destroy an existing tunnel.
248 * The existing end callback for the tunnel will be called immediately.
249 * Any pending outgoing messages will be sent but no incoming messages will be
250 * accepted and no data callbacks will be called.
252 * @param tunnel Tunnel handle, becomes invalid after this call.
255 GNUNET_MESH_tunnel_destroy (struct GNUNET_MESH_Tunnel *tunnel);
259 * Struct to retrieve info about a tunnel.
261 union GNUNET_MESH_TunnelInfo
265 * #GNUNET_YES / #GNUNET_NO, for binary flags.
270 * Peer on the other side of the tunnel
272 const struct GNUNET_PeerIdentity *peer;
277 * Get information about a tunnel.
279 * @param tunnel Tunnel handle.
280 * @param option Query, as listed in src/mesh/mesh.h (GNUNET_MESH_OPTION_*)
281 * @param ... dependant on option, currently not used
283 * @return Union with an answer to the query.
285 const union GNUNET_MESH_TunnelInfo *
286 GNUNET_MESH_tunnel_get_info (struct GNUNET_MESH_Tunnel *tunnel,
287 enum MeshTunnelOption option, ...);
291 * Handle for a transmission request.
293 struct GNUNET_MESH_TransmitHandle;
297 * Ask the mesh to call @a notify once it is ready to transmit the
298 * given number of bytes to the specified tunnel.
299 * Only one call can be active at any time, to issue another request,
300 * wait for the callback or cancel the current request.
302 * @param tunnel tunnel to use for transmission
303 * @param cork is corking allowed for this transmission?
304 * @param maxdelay how long can the message wait?
305 * @param notify_size how many bytes of buffer space does @a notify want?
306 * @param notify function to call when buffer space is available;
307 * will be called with NULL on timeout or if the overall queue
308 * for this peer is larger than queue_size and this is currently
309 * the message with the lowest priority
310 * @param notify_cls closure for @a notify
311 * @return non-NULL if the notify callback was queued,
312 * NULL if we can not even queue the request (insufficient
313 * memory); if NULL is returned, "notify" will NOT be called.
315 struct GNUNET_MESH_TransmitHandle *
316 GNUNET_MESH_notify_transmit_ready (struct GNUNET_MESH_Tunnel *tunnel, int cork,
317 struct GNUNET_TIME_Relative maxdelay,
319 GNUNET_CONNECTION_TransmitReadyNotify notify,
324 * Cancel the specified transmission-ready notification.
326 * @param th handle that was returned by "notify_transmit_ready".
329 GNUNET_MESH_notify_transmit_ready_cancel (struct GNUNET_MESH_TransmitHandle
334 * Indicate readiness to receive the next message on a tunnel.
336 * Should only be called once per handler called.
338 * @param tunnel Tunnel that will be allowed to call another handler.
341 GNUNET_MESH_receive_done (struct GNUNET_MESH_Tunnel *tunnel);
345 /******************************************************************************/
346 /******************** MONITORING /DEBUG API *************************/
347 /******************************************************************************/
348 /* The following calls are not useful for normal MESH operation, but for */
349 /* debug and monitoring of the mesh state. They can be safely ignored. */
350 /* The API can change at any point without notice. */
351 /* Please contact the developer if you consider any of this calls useful for */
352 /* normal mesh applications. */
353 /******************************************************************************/
356 * Method called to retrieve information about each tunnel the mesh peer
359 * @param cls Closure.
360 * @param tunnel_number Tunnel number.
361 * @param origin that started the tunnel (owner).
362 * @param target other endpoint of the tunnel
364 typedef void (*GNUNET_MESH_TunnelsCB) (void *cls,
365 uint32_t tunnel_number,
366 const struct GNUNET_PeerIdentity *origin,
367 const struct GNUNET_PeerIdentity *target);
371 * Method called to retrieve information about a specific tunnel the mesh peer
372 * is aware of, including all transit nodes.
374 * @param cls Closure.
375 * @param peer Peer in the tunnel's tree.
376 * @param parent Parent of the current peer. All 0 when peer is root.
378 typedef void (*GNUNET_MESH_TunnelCB) (void *cls,
379 const struct GNUNET_PeerIdentity *peer,
380 const struct GNUNET_PeerIdentity *parent);
384 * Request information about the running mesh peer.
385 * The callback will be called for every tunnel known to the service,
386 * listing all active peers that belong to the tunnel.
388 * If called again on the same handle, it will overwrite the previous
389 * callback and cls. To retrieve the cls, monitor_cancel must be
392 * WARNING: unstable API, likely to change in the future!
394 * @param h Handle to the mesh peer.
395 * @param callback Function to call with the requested data.
396 * @param callback_cls Closure for @c callback.
399 GNUNET_MESH_get_tunnels (struct GNUNET_MESH_Handle *h,
400 GNUNET_MESH_TunnelsCB callback,
405 * Request information about a specific tunnel of the running mesh peer.
407 * WARNING: unstable API, likely to change in the future!
409 * @param h Handle to the mesh peer.
410 * @param initiator ID of the owner of the tunnel.
411 * @param tunnel_number Tunnel number.
412 * @param callback Function to call with the requested data.
413 * @param callback_cls Closure for @a callback.
416 GNUNET_MESH_show_tunnel (struct GNUNET_MESH_Handle *h,
417 struct GNUNET_PeerIdentity *initiator,
418 uint32_t tunnel_number,
419 GNUNET_MESH_TunnelCB callback,
424 * Cancel a monitor request. The monitor callback will not be called.
426 * WARNING: unstable API, likely to change in the future!
428 * @param h Mesh handle.
430 * @return Closure given to GNUNET_MESH_monitor, if any.
433 GNUNET_MESH_get_tunnels_cancel (struct GNUNET_MESH_Handle *h);
437 * Create a message queue for a mesh tunnel.
438 * The message queue can only be used to transmit messages,
439 * not to receive them.
441 * @param tunnel the tunnel to create the message qeue for
442 * @return a message queue to messages over the tunnel
444 struct GNUNET_MQ_Handle *
445 GNUNET_MESH_mq_create (struct GNUNET_MESH_Tunnel *tunnel);
448 #if 0 /* keep Emacsens' auto-indent happy */
455 /* ifndef GNUNET_MESH_SERVICE_H */
457 /* end of gnunet_mesh_service.h */