/* This file is part of GNUnet. (C) 2009, 2010 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file include/gnunet_core_service.h * @brief core service; this is the main API for encrypted P2P * communications * @author Christian Grothoff */ #ifndef GNUNET_CORE_SERVICE_H #define GNUNET_CORE_SERVICE_H #ifdef __cplusplus extern "C" { #if 0 /* keep Emacsens' auto-indent happy */ } #endif #endif #include "gnunet_util_lib.h" /** * Version number of GNUnet-core API. */ #define GNUNET_CORE_VERSION 0x00000000 /** * Opaque handle to the service. */ struct GNUNET_CORE_Handle; /** * Method called whenever a given peer either connects. * * @param cls closure * @param peer peer identity this notification is about * @param latency reported latency of the connection with 'other' * @param distance reported distance (DV) to 'other' */ typedef void (*GNUNET_CORE_ConnectEventHandler) (void *cls, const struct GNUNET_PeerIdentity * peer, struct GNUNET_TIME_Relative latency, uint32_t distance); /** * Method called whenever a given peer either disconnects. * * @param cls closure * @param peer peer identity this notification is about */ typedef void (*GNUNET_CORE_DisconnectEventHandler) (void *cls, const struct GNUNET_PeerIdentity * peer); /** * Functions with this signature are called whenever a message is * received or transmitted. * * @param cls closure * @param peer the other peer involved (sender or receiver, NULL * for loopback messages where we are both sender and receiver) * @param message the actual message * @param latency reported latency of the connection with 'other' * @param distance reported distance (DV) to 'other' * @return GNUNET_OK to keep the connection open, * GNUNET_SYSERR to close it (signal serious error) */ typedef int (*GNUNET_CORE_MessageCallback) (void *cls, const struct GNUNET_PeerIdentity * other, const struct GNUNET_MessageHeader * message, struct GNUNET_TIME_Relative latency, uint32_t distance); /** * Message handler. Each struct specifies how to handle on particular * type of message received. */ struct GNUNET_CORE_MessageHandler { /** * Function to call for messages of "type". */ GNUNET_CORE_MessageCallback callback; /** * Type of the message this handler covers. */ uint16_t type; /** * Expected size of messages of this type. Use 0 for variable-size. * If non-zero, messages of the given type will be discarded if they * do not have the right size. */ uint16_t expected_size; }; /** * Function called after GNUNET_CORE_connect has succeeded * (or failed for good). Note that the private key of the * peer is intentionally not exposed here; if you need it, * your process should try to read the private key file * directly (which should work if you are authorized...). * * @param cls closure * @param server handle to the server, NULL if we failed * @param my_identity ID of this peer, NULL if we failed * @param publicKey public key of this peer, NULL if we failed */ typedef void (*GNUNET_CORE_StartupCallback) (void *cls, struct GNUNET_CORE_Handle * server, const struct GNUNET_PeerIdentity * my_identity, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded * publicKey); /** * Connect to the core service. Note that the connection may complete * (or fail) asynchronously. This function primarily causes the given * callback notification functions to be invoked whenever the * specified event happens. The maximum number of queued * notifications (queue length) is per client but the queue is shared * across all types of notifications. So a slow client that registers * for 'outbound_notify' also risks missing 'inbound_notify' messages. * Certain events (such as connect/disconnect notifications) are not * subject to queue size limitations. * * @param sched scheduler to use * @param cfg configuration to use * @param timeout after how long should we give up trying to connect to the core service? * @param cls closure for the various callbacks that follow (including handlers in the handlers array) * @param init callback to call on timeout or once we have successfully * connected to the core service; note that timeout is only meaningful if init is not NULL * @param pre_connects function to call on peer pre-connect (no session key yet), can be NULL * @param connects function to call on peer connect, can be NULL * @param disconnects function to call on peer disconnect / timeout, can be NULL * @param inbound_notify function to call for all inbound messages, can be NULL * note that the core is allowed to drop notifications about inbound * messages if the client does not process them fast enough (for this * notification type, a bounded queue is used) * @param inbound_hdr_only set to GNUNET_YES if inbound_notify will only read the * GNUNET_MessageHeader and hence we do not need to give it the full message; * can be used to improve efficiency, ignored if inbound_notify is NULL * note that the core is allowed to drop notifications about inbound * messages if the client does not process them fast enough (for this * notification type, a bounded queue is used) * @param outbound_notify function to call for all outbound messages, can be NULL; * note that the core is allowed to drop notifications about outbound * messages if the client does not process them fast enough (for this * notification type, a bounded queue is used) * @param outbound_hdr_only set to GNUNET_YES if outbound_notify will only read the * GNUNET_MessageHeader and hence we do not need to give it the full message * can be used to improve efficiency, ignored if outbound_notify is NULL * note that the core is allowed to drop notifications about outbound * messages if the client does not process them fast enough (for this * notification type, a bounded queue is used) * @param handlers callbacks for messages we care about, NULL-terminated * note that the core is allowed to drop notifications about inbound * messages if the client does not process them fast enough (for this * notification type, a bounded queue is used) * @return handle to the core service (only useful for disconnect until 'init' is called), * NULL on error (in this case, init is never called) */ struct GNUNET_CORE_Handle * GNUNET_CORE_connect (struct GNUNET_SCHEDULER_Handle *sched, const struct GNUNET_CONFIGURATION_Handle *cfg, struct GNUNET_TIME_Relative timeout, void *cls, GNUNET_CORE_StartupCallback init, GNUNET_CORE_ConnectEventHandler pre_connects, GNUNET_CORE_ConnectEventHandler connects, GNUNET_CORE_DisconnectEventHandler disconnects, GNUNET_CORE_MessageCallback inbound_notify, int inbound_hdr_only, GNUNET_CORE_MessageCallback outbound_notify, int outbound_hdr_only, const struct GNUNET_CORE_MessageHandler *handlers); /** * Disconnect from the core service. * * @param handle connection to core to disconnect */ void GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle); /** * Handle for a request to the core to connect or disconnect * from a particular peer. Can be used to cancel the request * (before the 'cont'inuation is called). */ struct GNUNET_CORE_PeerRequestHandle; /** * Request that the core should try to connect to a particular peer. * Once the request has been transmitted to the core, the continuation * function will be called. Note that this does NOT mean that a * connection was successfully established -- it only means that the * core will now try. Successful establishment of the connection * will be signalled to the 'connects' callback argument of * 'GNUNET_CORE_connect' only. If the core service does not respond * to our connection attempt within the given time frame, 'cont' will * be called with the TIMEOUT reason code. * * @param sched scheduler to use * @param cfg configuration to use * @param timeout how long to try to talk to core * @param peer who should we connect to * @param cont function to call once the request has been completed (or timed out) * @param cont_cls closure for cont * @return NULL on error (cont will not be called), otherwise handle for cancellation */ struct GNUNET_CORE_PeerRequestHandle * GNUNET_CORE_peer_request_connect (struct GNUNET_SCHEDULER_Handle *sched, const struct GNUNET_CONFIGURATION_Handle *cfg, struct GNUNET_TIME_Relative timeout, const struct GNUNET_PeerIdentity * peer, GNUNET_SCHEDULER_Task cont, void *cont_cls); /** * Cancel a pending request to connect to a particular peer. Must not * be called after the 'cont' function was invoked. * * @param req request handle that was returned for the original request */ void GNUNET_CORE_peer_request_connect_cancel (struct GNUNET_CORE_PeerRequestHandle *req); /** * Function called with statistics about the given peer. * * @param cls closure * @param peer identifies the peer * @param bpm_in set to the current bandwidth limit (receiving) for this peer * @param bpm_out set to the current bandwidth limit (sending) for this peer * @param latency current latency estimate, "FOREVER" if we have been * disconnected * @param amount set to the amount that was actually reserved or unreserved * @param preference current traffic preference for the given peer */ typedef void (*GNUNET_CORE_PeerConfigurationInfoCallback) (void *cls, const struct GNUNET_PeerIdentity * peer, unsigned int bpm_in, unsigned int bpm_out, int amount, uint64_t preference); /** * Context that can be used to cancel a peer information request. */ struct GNUNET_CORE_InformationRequestContext; /** * Obtain statistics and/or change preferences for the given peer. * * @param sched scheduler to use * @param cfg configuration to use * @param peer identifies the peer * @param timeout after how long should we give up (and call "info" with NULL * for "peer" to signal an error)? * @param bpm_out set to the current bandwidth limit (sending) for this peer, * caller should set "bpm_out" to "-1" to avoid changing * the current value; otherwise "bpm_out" will be lowered to * the specified value; passing a pointer to "0" can be used to force * us to disconnect from the peer; "bpm_out" might not increase * as specified since the upper bound is generally * determined by the other peer! * @param amount reserve N bytes for receiving, negative * amounts can be used to undo a (recent) reservation; * @param preference increase incoming traffic share preference by this amount; * in the absence of "amount" reservations, we use this * preference value to assign proportional bandwidth shares * to all connected peers * @param info function to call with the resulting configuration information * @param info_cls closure for info * @return NULL on error */ struct GNUNET_CORE_InformationRequestContext * GNUNET_CORE_peer_change_preference (struct GNUNET_SCHEDULER_Handle *sched, const struct GNUNET_CONFIGURATION_Handle *cfg, const struct GNUNET_PeerIdentity *peer, struct GNUNET_TIME_Relative timeout, uint32_t bpm_out, int32_t amount, uint64_t preference, GNUNET_CORE_PeerConfigurationInfoCallback info, void *info_cls); /** * Cancel request for getting information about a peer. * * @param irc context returned by the original GNUNET_CORE_peer_get_info call */ void GNUNET_CORE_peer_change_preference_cancel (struct GNUNET_CORE_InformationRequestContext *irc); /** * Handle for a transmission request. */ struct GNUNET_CORE_TransmitHandle; /** * Ask the core to call "notify" once it is ready to transmit the * given number of bytes to the specified "target". If we are not yet * connected to the specified peer, a call to this function will cause * us to try to establish a connection. * * @param handle connection to core service * @param priority how important is the message? * @param maxdelay how long can the message wait? * @param target who should receive the message, * use NULL for this peer (loopback) * @param notify_size how many bytes of buffer space does notify want? * @param notify function to call when buffer space is available * @param notify_cls closure for notify * @return non-NULL if the notify callback was queued, * NULL if we can not even queue the request (insufficient * memory); if NULL is returned, "notify" will NOT be called. */ struct GNUNET_CORE_TransmitHandle * GNUNET_CORE_notify_transmit_ready (struct GNUNET_CORE_Handle *handle, uint32_t priority, struct GNUNET_TIME_Relative maxdelay, const struct GNUNET_PeerIdentity *target, size_t notify_size, GNUNET_CONNECTION_TransmitReadyNotify notify, void *notify_cls); /** * Cancel the specified transmission-ready notification. * * @param h handle that was returned by "notify_transmit_ready". */ void GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle *h); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif /* ifndef GNUNET_CORE_SERVICE_H */ #endif /* end of gnunet_core_service.h */