/* This file is part of GNUnet. (C) 2009, 2010, 2011, 2012, 2013 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_mesh_service.h * @brief mesh service; establish tunnels to distant peers * @author Christian Grothoff * * TODO: * - need to do sanity check that this is consistent * with current ideas for the multicast layer's needs */ #ifndef GNUNET_MESH_SERVICE_H #define GNUNET_MESH_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-mesh API. */ #define GNUNET_MESH_VERSION 0x00000002 /** * Opaque handle to the service. */ struct GNUNET_MESH_Handle; /** * Opaque handle to a tunnel. */ struct GNUNET_MESH_Tunnel; /** * Options for querying a tunnel. * Second line indicates filed in the MeshTunnelInfo union carrying the answer. */ enum MeshTunnelOption { /** * Disable buffering on intermediate nodes (for minimum latency). * Yes/No. */ GNUNET_MESH_OPTION_NOBUFFER = 0x1, /** * Enable tunnel reliability, lost messages will be retransmitted. * Yes/No. */ GNUNET_MESH_OPTION_RELIABLE = 0x2, /** * Enable out of order delivery of messages. * Yes/No. */ GNUNET_MESH_OPTION_OOORDER = 0x4, /** * Who is the peer at the other end of the tunnel. * struct GNUNET_PeerIdentity *peer */ GNUNET_MESH_OPTION_PEER = 0x8 }; /** * Functions with this signature are called whenever a message is * received. * * Each time the function must call #GNUNET_MESH_receive_done on the tunnel * in order to receive the next message. This doesn't need to be immediate: * can be delayed if some processing is done on the message. * * @param cls Closure (set from #GNUNET_MESH_connect). * @param tunnel Connection to the other end. * @param tunnel_ctx Place to store local state associated with the tunnel. * @param message The actual message. * * @return GNUNET_OK to keep the tunnel open, * GNUNET_SYSERR to close it (signal serious error). */ typedef int (*GNUNET_MESH_MessageCallback) (void *cls, struct GNUNET_MESH_Tunnel *tunnel, void **tunnel_ctx, const struct GNUNET_MessageHeader *message); /** * Message handler. Each struct specifies how to handle on particular * type of message received. */ struct GNUNET_MESH_MessageHandler { /** * Function to call for messages of "type". */ GNUNET_MESH_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; }; /** * Method called whenever another peer has added us to a tunnel * the other peer initiated. * Only called (once) upon reception of data with a message type which was * subscribed to in GNUNET_MESH_connect. A call to GNUNET_MESH_tunnel_destroy * causes te tunnel to be ignored and no further notifications are sent about * the same tunnel. * * @param cls closure * @param tunnel new handle to the tunnel * @param initiator peer that started the tunnel * @param port Port this tunnel is for. * @return initial tunnel context for the tunnel * (can be NULL -- that's not an error) */ typedef void *(GNUNET_MESH_InboundTunnelNotificationHandler) (void *cls, struct GNUNET_MESH_Tunnel * tunnel, const struct GNUNET_PeerIdentity * initiator, uint32_t port); /** * Function called whenever a tunnel is destroyed. Should clean up * any associated state. * * It must NOT call GNUNET_MESH_tunnel_destroy on the tunnel. * * @param cls closure (set from GNUNET_MESH_connect) * @param tunnel connection to the other end (henceforth invalid) * @param tunnel_ctx place where local state associated * with the tunnel is stored */ typedef void (GNUNET_MESH_TunnelEndHandler) (void *cls, const struct GNUNET_MESH_Tunnel * tunnel, void *tunnel_ctx); /** * Connect to the mesh service. * * @param cfg Configuration to use. * @param cls Closure for the various callbacks that follow (including * handlers in the handlers array). * @param new_tunnel Function called when an *incoming* tunnel is created. * Can be NULL if no inbound tunnels are desired. * See @c ports. * @param cleaner Function called when a tunnel is destroyed by the remote peer. * It is NOT called if GNUNET_MESH_tunnel_destroy is called on * the tunnel. * @param handlers Callbacks for messages we care about, NULL-terminated. Each * one must call #GNUNET_MESH_receive_done on the tunnel to * receive the next message. Messages of a type that is not * in the handlers array are ignored if received. * @param ports NULL or 0-terminated array of port numbers for incoming tunnels. * See @c new_tunnel. * * @return handle to the mesh service NULL on error * (in this case, init is never called) */ struct GNUNET_MESH_Handle * GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, void *cls, GNUNET_MESH_InboundTunnelNotificationHandler new_tunnel, GNUNET_MESH_TunnelEndHandler cleaner, const struct GNUNET_MESH_MessageHandler *handlers, const uint32_t *ports); /** * Disconnect from the mesh service. All tunnels will be destroyed. All tunnel * disconnect callbacks will be called on any still connected peers, notifying * about their disconnection. The registered inbound tunnel cleaner will be * called should any inbound tunnels still exist. * * @param handle connection to mesh to disconnect */ void GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle); /** * Create a new tunnel (we're initiator and will be allowed to add/remove peers * and to broadcast). * * @param h mesh handle * @param tunnel_ctx client's tunnel context to associate with the tunnel * @param peer peer identity the tunnel should go to * @param port Port number. * @param nobuffer Flag for disabling buffering on relay nodes. * @param reliable Flag for end-to-end reliability. * * @return handle to the tunnel */ struct GNUNET_MESH_Tunnel * GNUNET_MESH_tunnel_create (struct GNUNET_MESH_Handle *h, void *tunnel_ctx, const struct GNUNET_PeerIdentity *peer, uint32_t port, int nobuffer, int reliable); /** * Destroy an existing tunnel. * * The existing end callback for the tunnel will be called immediately. * Any pending outgoing messages will be sent but no incoming messages will be * accepted and no data callbacks will be called. * * @param tunnel Tunnel handle, becomes invalid after this call. */ void GNUNET_MESH_tunnel_destroy (struct GNUNET_MESH_Tunnel *tunnel); /** * Struct to retrieve info about a tunnel. */ union MeshTunnelInfo { /** * GNUNET_YES / GNUNET_NO, for binary flags. */ int yes_no; /** * Peer on the other side of the tunnel */ struct GNUNET_PeerIdentity *peer; }; /** * Get information about a tunnel. * * @param tunnel Tunnel handle. * @param option Query, as listed in src/mesh/mesh.h (GNUNET_MESH_OPTION_*) * @param ... dependant on option, currently not used * * @return Union with an answer to the query. */ const union MeshTunnelInfo * GNUNET_MESH_tunnel_get_info (struct GNUNET_MESH_Tunnel *tunnel, enum MeshTunnelOption option, ...); /** * Handle for a transmission request. */ struct GNUNET_MESH_TransmitHandle; /** * Ask the mesh to call "notify" once it is ready to transmit the * given number of bytes to the specified tunnel. * Only one call can be active at any time, to issue another request, * wait for the callback or cancel the current request. * * @param tunnel tunnel to use for transmission * @param cork is corking allowed for this transmission? * @param maxdelay how long can the message wait? * @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 * @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_MESH_TransmitHandle * GNUNET_MESH_notify_transmit_ready (struct GNUNET_MESH_Tunnel *tunnel, int cork, struct GNUNET_TIME_Relative maxdelay, 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_MESH_notify_transmit_ready_cancel (struct GNUNET_MESH_TransmitHandle *th); /** * Indicate readiness to receive the next message on a tunnel. * * Should only be called once per handler called. * * @param tunnel Tunnel that will be allowed to call another handler. */ void GNUNET_MESH_receive_done (struct GNUNET_MESH_Tunnel *tunnel); /******************************************************************************/ /******************** MONITORING /DEBUG API *************************/ /******************************************************************************/ /* The following calls are not useful for normal MESH operation, but for */ /* debug and monitoring of the mesh state. They can be safely ignored. */ /* The API can change at any point without notice. */ /* Please contact the developer if you consider any of this calls useful for */ /* normal mesh applications. */ /******************************************************************************/ /** * Method called to retrieve information about each tunnel the mesh peer * is aware of. * * @param cls Closure. * @param tunnel_number Tunnel number. * @param origin that started the tunnel (owner). * @param target other endpoint of the tunnel */ typedef void (*GNUNET_MESH_TunnelsCB) (void *cls, uint32_t tunnel_number, const struct GNUNET_PeerIdentity *origin, const struct GNUNET_PeerIdentity *target); /** * Method called to retrieve information about a specific tunnel the mesh peer * is aware of, including all transit nodes. * * @param cls Closure. * @param peer Peer in the tunnel's tree. * @param parent Parent of the current peer. All 0 when peer is root. */ typedef void (*GNUNET_MESH_TunnelCB) (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_PeerIdentity *parent); /** * Request information about the running mesh peer. * The callback will be called for every tunnel known to the service, * listing all active peers that belong to the tunnel. * * If called again on the same handle, it will overwrite the previous * callback and cls. To retrieve the cls, monitor_cancel must be * called first. * * WARNING: unstable API, likely to change in the future! * * @param h Handle to the mesh peer. * @param callback Function to call with the requested data. * @param callback_cls Closure for @c callback. */ void GNUNET_MESH_get_tunnels (struct GNUNET_MESH_Handle *h, GNUNET_MESH_TunnelsCB callback, void *callback_cls); /** * Request information about a specific tunnel of the running mesh peer. * * WARNING: unstable API, likely to change in the future! * * @param h Handle to the mesh peer. * @param initiator ID of the owner of the tunnel. * @param tunnel_number Tunnel number. * @param callback Function to call with the requested data. * @param callback_cls Closure for @c callback. */ void GNUNET_MESH_show_tunnel (struct GNUNET_MESH_Handle *h, struct GNUNET_PeerIdentity *initiator, uint32_t tunnel_number, GNUNET_MESH_TunnelCB callback, void *callback_cls); /** * Cancel a monitor request. The monitor callback will not be called. * * WARNING: unstable API, likely to change in the future! * * @param h Mesh handle. * * @return Closure given to GNUNET_MESH_monitor, if any. */ void * GNUNET_MESH_get_tunnels_cancel (struct GNUNET_MESH_Handle *h); /** * Create a message queue for a mesh tunnel. * The message queue can only be used to transmit messages, * not to receive them. * * @param tunnel the tunnel to create the message qeue for * @return a message queue to messages over the tunnel */ struct GNUNET_MQ_Handle * GNUNET_MESH_mq_create (struct GNUNET_MESH_Tunnel *tunnel); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif /* ifndef GNUNET_MESH_SERVICE_H */ #endif /* end of gnunet_mesh_service.h */