2 This file is part of GNUnet.
3 (C) 2009-2013 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
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13 General Public License for more details.
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22 * @file include/gnunet_core_service.h
23 * @brief core service; this is the main API for encrypted P2P
25 * @author Christian Grothoff
26 * @defgroup core encrypted direct communication between peers
30 #ifndef GNUNET_CORE_SERVICE_H
31 #define GNUNET_CORE_SERVICE_H
36 #if 0 /* keep Emacsens' auto-indent happy */
41 #include "gnunet_util_lib.h"
42 #include "gnunet_transport_service.h"
45 * Version number of GNUnet-core API.
47 #define GNUNET_CORE_VERSION 0x00000001
51 * Opaque handle to the service.
53 struct GNUNET_CORE_Handle;
57 * Method called whenever a given peer connects.
60 * @param peer peer identity this notification is about
62 typedef void (*GNUNET_CORE_ConnectEventHandler) (void *cls,
63 const struct GNUNET_PeerIdentity *peer);
67 * Method called whenever a peer disconnects.
70 * @param peer peer identity this notification is about
72 typedef void (*GNUNET_CORE_DisconnectEventHandler) (void *cls,
73 const struct GNUNET_PeerIdentity *peer);
77 * Functions with this signature are called whenever a message is
78 * received or transmitted.
80 * @param cls closure (set from #GNUNET_CORE_connect)
81 * @param peer the other peer involved (sender or receiver, NULL
82 * for loopback messages where we are both sender and receiver)
83 * @param message the actual message
84 * @return #GNUNET_OK to keep the connection open,
85 * #GNUNET_SYSERR to close connection to the peer (signal serious error)
87 typedef int (*GNUNET_CORE_MessageCallback) (void *cls,
88 const struct GNUNET_PeerIdentity *
90 const struct GNUNET_MessageHeader *
95 * Message handler. Each struct specifies how to handle on particular
96 * type of message received.
98 struct GNUNET_CORE_MessageHandler
101 * Function to call for messages of "type".
103 GNUNET_CORE_MessageCallback callback;
106 * Type of the message this handler covers.
111 * Expected size of messages of this type. Use 0 for variable-size.
112 * If non-zero, messages of the given type will be discarded if they
113 * do not have the right size.
115 uint16_t expected_size;
121 * Function called after #GNUNET_CORE_connect has succeeded (or failed
122 * for good). Note that the private key of the peer is intentionally
123 * not exposed here; if you need it, your process should try to read
124 * the private key file directly (which should work if you are
125 * authorized...). Implementations of this function must not call
126 * #GNUNET_CORE_disconnect (other than by scheduling a new task to
130 * @param server handle to the server, NULL if we failed;
131 * TODO: consider removing this argument, it is redundant...
132 * @param my_identity ID of this peer, NULL if we failed
134 typedef void (*GNUNET_CORE_StartupCallback) (void *cls,
135 struct GNUNET_CORE_Handle * server,
136 const struct GNUNET_PeerIdentity *my_identity);
140 * Connect to the core service. Note that the connection may complete
141 * (or fail) asynchronously. This function primarily causes the given
142 * callback notification functions to be invoked whenever the
143 * specified event happens. The maximum number of queued
144 * notifications (queue length) is per client; the queue is shared
145 * across all types of notifications. So a slow client that registers
146 * for @a outbound_notify also risks missing @a inbound_notify messages.
147 * Certain events (such as connect/disconnect notifications) are not
148 * subject to queue size limitations.
150 * @param cfg configuration to use
151 * @param cls closure for the various callbacks that follow (including handlers in the handlers array)
152 * @param init callback to call once we have successfully
153 * connected to the core service
154 * @param connects function to call on peer connect, can be NULL
155 * @param disconnects function to call on peer disconnect / timeout, can be NULL
156 * @param inbound_notify function to call for all inbound messages, can be NULL
157 * note that the core is allowed to drop notifications about inbound
158 * messages if the client does not process them fast enough (for this
159 * notification type, a bounded queue is used)
160 * @param inbound_hdr_only set to #GNUNET_YES if @a inbound_notify will only read the
161 * GNUNET_MessageHeader and hence we do not need to give it the full message;
162 * can be used to improve efficiency, ignored if inbound_notify is NULL
163 * note that the core is allowed to drop notifications about inbound
164 * messages if the client does not process them fast enough (for this
165 * notification type, a bounded queue is used)
166 * @param outbound_notify function to call for all outbound messages, can be NULL;
167 * note that the core is allowed to drop notifications about outbound
168 * messages if the client does not process them fast enough (for this
169 * notification type, a bounded queue is used)
170 * @param outbound_hdr_only set to #GNUNET_YES if @a outbound_notify will only read the
171 * GNUNET_MessageHeader and hence we do not need to give it the full message
172 * can be used to improve efficiency, ignored if outbound_notify is NULL
173 * note that the core is allowed to drop notifications about outbound
174 * messages if the client does not process them fast enough (for this
175 * notification type, a bounded queue is used)
176 * @param handlers callbacks for messages we care about, NULL-terminated
177 * note that the core is allowed to drop notifications about inbound
178 * messages if the client does not process them fast enough (for this
179 * notification type, a bounded queue is used)
180 * @return handle to the core service (only useful for disconnect until @a init is called),
181 * NULL on error (in this case, init is never called)
183 struct GNUNET_CORE_Handle *
184 GNUNET_CORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
186 GNUNET_CORE_StartupCallback init,
187 GNUNET_CORE_ConnectEventHandler connects,
188 GNUNET_CORE_DisconnectEventHandler disconnects,
189 GNUNET_CORE_MessageCallback inbound_notify,
190 int inbound_hdr_only,
191 GNUNET_CORE_MessageCallback outbound_notify,
192 int outbound_hdr_only,
193 const struct GNUNET_CORE_MessageHandler *handlers);
197 * Disconnect from the core service. This function can only
198 * be called *after* all pending #GNUNET_CORE_notify_transmit_ready
199 * requests have been explicitly cancelled.
201 * @param handle connection to core to disconnect
204 GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle);
208 * Handle for a transmission request.
210 struct GNUNET_CORE_TransmitHandle;
214 * Ask the core to call @a notify once it is ready to transmit the
215 * given number of bytes to the specified @a target. Must only be
216 * called after a connection to the respective peer has been
217 * established (and the client has been informed about this). You may
218 * have one request of this type pending for each connected peer at
219 * any time. If a peer disconnects, the application MUST call
220 * #GNUNET_CORE_notify_transmit_ready_cancel on the respective
221 * transmission request, if one such request is pending.
223 * @param handle connection to core service
224 * @param cork is corking allowed for this transmission?
225 * @param priority how important is the message?
226 * @param maxdelay how long can the message wait?
227 * @param target who should receive the message, never NULL (can be this peer's identity for loopback)
228 * @param notify_size how many bytes of buffer space does notify want?
229 * @param notify function to call when buffer space is available;
230 * will be called with NULL on timeout; clients MUST cancel
231 * all pending transmission requests DURING the disconnect
233 * @param notify_cls closure for @a notify
234 * @return non-NULL if the notify callback was queued,
235 * NULL if we can not even queue the request (request already pending);
236 * if NULL is returned, "notify" will NOT be called.
238 struct GNUNET_CORE_TransmitHandle *
239 GNUNET_CORE_notify_transmit_ready (struct GNUNET_CORE_Handle *handle, int cork,
241 struct GNUNET_TIME_Relative maxdelay,
242 const struct GNUNET_PeerIdentity *target,
244 GNUNET_CONNECTION_TransmitReadyNotify notify,
249 * Cancel the specified transmission-ready notification.
251 * @param th handle that was returned by "notify_transmit_ready".
254 GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle
259 * Iterate over all connected peers. Calls @a peer_cb with each
260 * connected peer, and then once with NULL to indicate that all peers
261 * have been handled. Normal users of the CORE API are not expected
262 * to use this function. It is different in that it truly lists
263 * all connections, not just those relevant to the application. This
264 * function is used by special applications for diagnostics. This
265 * function is NOT part of the 'versioned', 'official' API.
267 * FIXME: we should probably make it possible to 'cancel' the
270 * @param cfg configuration handle
271 * @param peer_cb function to call with the peer information
272 * @param cb_cls closure for @a peer_cb
273 * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
276 GNUNET_CORE_iterate_peers (const struct GNUNET_CONFIGURATION_Handle *cfg,
277 GNUNET_CORE_ConnectEventHandler peer_cb,
282 * Check if the given peer is currently connected. This function is for special
283 * cirumstances (GNUNET_TESTBED uses it), normal users of the CORE API are
284 * expected to track which peers are connected based on the connect/disconnect
285 * callbacks from #GNUNET_CORE_connect. This function is NOT part of the
286 * 'versioned', 'official' API. The difference between this function and the
287 * function #GNUNET_CORE_is_peer_connected is that this one returns
288 * synchronously after looking in the CORE API cache. The function
289 * #GNUNET_CORE_is_peer_connected sends a message to the CORE service and hence
290 * its response is given asynchronously.
292 * @param h the core handle
293 * @param pid the identity of the peer to check if it has been connected to us
294 * @return #GNUNET_YES if the peer is connected to us; #GNUNET_NO if not
297 GNUNET_CORE_is_peer_connected_sync (const struct GNUNET_CORE_Handle *h,
298 const struct GNUNET_PeerIdentity *pid);
301 #if 0 /* keep Emacsens' auto-indent happy */
308 /** @} */ /* end of group core */
310 /* ifndef GNUNET_CORE_SERVICE_H */
312 /* end of gnunet_core_service.h */