/* 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 3, 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" #include "gnunet_transport_service.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 connects. * * @param cls closure * @param peer peer identity this notification is about * @param atsi performance data for the connection * @param atsi_count number of records in 'atsi' */ typedef void (*GNUNET_CORE_ConnectEventHandler) (void *cls, const struct GNUNET_PeerIdentity * peer, const struct GNUNET_ATS_Information * atsi, unsigned int atsi_count); /** * Method called whenever a peer 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 (set from GNUNET_CORE_connect) * @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 atsi performance data for the connection * @param atsi_count number of records in 'atsi' * @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, const struct GNUNET_ATS_Information * atsi, unsigned int atsi_count); /** * 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 */ typedef void (*GNUNET_CORE_StartupCallback) (void *cls, struct GNUNET_CORE_Handle * server, const struct GNUNET_PeerIdentity * my_identity); /** * 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 cfg configuration to use * @param queue_size size of the per-peer message queue * @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 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 (const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int queue_size, void *cls, GNUNET_CORE_StartupCallback init, 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. This function can only * be called *after* all pending 'GNUNET_CORE_notify_transmit_ready' * requests have been explicitly cancelled. * * @param handle connection to core to disconnect */ void GNUNET_CORE_disconnect (struct GNUNET_CORE_Handle *handle); /** * 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". Must only be * called after a connection to the respective peer has been * established (and the client has been informed about this). * * * @param handle connection to core service * @param cork is corking allowed for this transmission? * @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; * will be called with NULL on timeout or if the overall queue * for this peer is larger than queue_size and this is currently * the message with the lowest priority; will also be called * with 'NULL' buf if the peer disconnects; since the disconnect * signal will be emmitted even later, clients MUST cancel * all pending transmission requests DURING the disconnect * handler (unless they ensure that 'notify' never calls * 'GNUNET_CORE_notify_transmit_ready'). * @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, int cork, 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 th handle that was returned by "notify_transmit_ready". */ void GNUNET_CORE_notify_transmit_ready_cancel (struct GNUNET_CORE_TransmitHandle *th); /** * Iterate over all connected peers. Calls peer_cb with each * connected peer, and then once with NULL to indicate that all peers * have been handled. Normal users of the CORE API are not expected * to use this function. It is different in that it truly lists * all connections, not just those relevant to the application. This * function is used by special applications for diagnostics. This * function is NOT part of the 'versioned', 'official' API. * * FIXME: we should probably make it possible to 'cancel' the * operation... * * @param cfg configuration handle * @param peer_cb function to call with the peer information * @param cb_cls closure for peer_cb * @return GNUNET_OK on success, GNUNET_SYSERR on errors */ int GNUNET_CORE_iterate_peers (const struct GNUNET_CONFIGURATION_Handle *cfg, GNUNET_CORE_ConnectEventHandler peer_cb, void *cb_cls); /** * Check if the given peer is currently connected and return information * about the session if so. This function is for special cirumstances * (GNUNET_TESTING uses it), normal users of the CORE API are * expected to track which peers are connected based on the * connect/disconnect callbacks from GNUNET_CORE_connect. This * function is NOT part of the 'versioned', 'official' API. * * FIXME: we should probably make it possible to 'cancel' the * operation... * * @param cfg configuration to use * @param peer the specific peer to check for * @param peer_cb function to call with the peer information * @param cb_cls closure for peer_cb * @return GNUNET_OK if iterating, GNUNET_SYSERR on error */ int GNUNET_CORE_is_peer_connected (const struct GNUNET_CONFIGURATION_Handle *cfg, struct GNUNET_PeerIdentity *peer, GNUNET_CORE_ConnectEventHandler peer_cb, void *cb_cls); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif /* ifndef GNUNET_CORE_SERVICE_H */ #endif /* end of gnunet_core_service.h */