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- /*
- This file is part of GNUnet.
- Copyright (C) 2009-2014 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., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA.
- */
- /**
- * @author Christian Grothoff
- * @author Bart Polot
- *
- * @file
- * CADET service; establish channels to distant peers
- *
- * @defgroup cadet CADET service
- * Confidential Ad-hoc Decentralized End-to-End Transport
- *
- * See also:
- * - [CADET documentation](https://gnunet.org/cadet-subsystem)
- * - [CADET paper](https://gnunet.org/cadet)
- *
- * @{
- */
- #ifndef GNUNET_CADET_SERVICE_H
- #define GNUNET_CADET_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-cadet API.
- */
- #define GNUNET_CADET_VERSION 0x00000003
- /**
- * Opaque handle to the service.
- */
- struct GNUNET_CADET_Handle;
- /**
- * Opaque handle to a channel.
- */
- struct GNUNET_CADET_Channel;
- /**
- * Hash to be used in Cadet communication. Only 256 bits needed,
- * instead of the 512 from `struct GNUNET_HashCode`.
- */
- struct GNUNET_CADET_Hash
- {
- unsigned char bits[256 / 8];
- };
- /**
- * Channel options. Second line indicates filed in the
- * CadetChannelInfo union carrying the answer.
- */
- enum GNUNET_CADET_ChannelOption
- {
- /**
- * Default options: unreliable, default buffering, not out of order.
- */
- GNUNET_CADET_OPTION_DEFAULT = 0x0,
- /**
- * Disable buffering on intermediate nodes (for minimum latency).
- * Yes/No.
- */
- GNUNET_CADET_OPTION_NOBUFFER = 0x1,
- /**
- * Enable channel reliability, lost messages will be retransmitted.
- * Yes/No.
- */
- GNUNET_CADET_OPTION_RELIABLE = 0x2,
- /**
- * Enable out of order delivery of messages.
- * Yes/No.
- */
- GNUNET_CADET_OPTION_OOORDER = 0x4,
- /**
- * Who is the peer at the other end of the channel.
- * Only for use in @c GNUNET_CADET_channel_get_info
- * struct GNUNET_PeerIdentity *peer
- */
- GNUNET_CADET_OPTION_PEER = 0x8
- };
- /**
- * Functions with this signature are called whenever a message is
- * received.
- *
- * Each time the function must call #GNUNET_CADET_receive_done on the channel
- * 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_CADET_connect).
- * @param channel Connection to the other end.
- * @param channel_ctx Place to store local state associated with the channel.
- * @param message The actual message.
- * @return #GNUNET_OK to keep the channel open,
- * #GNUNET_SYSERR to close it (signal serious error).
- */
- typedef int
- (*GNUNET_CADET_MessageCallback) (void *cls,
- struct GNUNET_CADET_Channel *channel,
- void **channel_ctx,
- const struct GNUNET_MessageHeader *message);
- /**
- * Message handler. Each struct specifies how to handle on particular
- * type of message received.
- */
- struct GNUNET_CADET_MessageHandler
- {
- /**
- * Function to call for messages of type @e type.
- */
- GNUNET_CADET_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 channel
- * the other peer initiated.
- * Only called (once) upon reception of data with a message type which was
- * subscribed to in #GNUNET_CADET_connect.
- *
- * A call to #GNUNET_CADET_channel_destroy causes te channel to be ignored. In
- * this case the handler MUST return NULL.
- *
- * @param cls closure
- * @param channel new handle to the channel
- * @param initiator peer that started the channel
- * @param port Port this channel is for.
- * @param options CadetOption flag field, with all active option bits set to 1.
- *
- * @return initial channel context for the channel
- * (can be NULL -- that's not an error)
- */
- typedef void *
- (GNUNET_CADET_InboundChannelNotificationHandler) (void *cls,
- struct GNUNET_CADET_Channel *channel,
- const struct GNUNET_PeerIdentity *initiator,
- uint32_t port,
- enum GNUNET_CADET_ChannelOption options);
- /**
- * Function called whenever a channel is destroyed. Should clean up
- * any associated state, including cancelling any pending transmission on this
- * channel.
- *
- * It must NOT call #GNUNET_CADET_channel_destroy on the channel.
- *
- * @param cls closure (set from #GNUNET_CADET_connect)
- * @param channel connection to the other end (henceforth invalid)
- * @param channel_ctx place where local state associated
- * with the channel is stored
- */
- typedef void
- (GNUNET_CADET_ChannelEndHandler) (void *cls,
- const struct GNUNET_CADET_Channel *channel,
- void *channel_ctx);
- /**
- * Connect to the cadet service.
- *
- * @param cfg Configuration to use.
- * @param cls Closure for the various callbacks that follow (including
- * handlers in the handlers array).
- * @param new_channel Function called when an *incoming* channel is created.
- * Can be NULL if no inbound channels are desired.
- * See @a ports.
- * @param cleaner Function called when a channel is destroyed.
- * It is called immediately if #GNUNET_CADET_channel_destroy
- * is called on the channel.
- * @param handlers Callbacks for messages we care about, NULL-terminated. Each
- * one must call #GNUNET_CADET_receive_done on the channel 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 channels.
- * See @a new_channel.
- *
- * @return handle to the cadet service NULL on error
- * (in this case, init is never called)
- */
- struct GNUNET_CADET_Handle *
- GNUNET_CADET_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
- void *cls,
- GNUNET_CADET_InboundChannelNotificationHandler new_channel,
- GNUNET_CADET_ChannelEndHandler cleaner,
- const struct GNUNET_CADET_MessageHandler *handlers,
- const uint32_t *ports);
- /**
- * Disconnect from the cadet service. All channels will be destroyed. All channel
- * disconnect callbacks will be called on any still connected peers, notifying
- * about their disconnection. The registered inbound channel cleaner will be
- * called should any inbound channels still exist.
- *
- * @param handle connection to cadet to disconnect
- */
- void
- GNUNET_CADET_disconnect (struct GNUNET_CADET_Handle *handle);
- /**
- * Create a new channel towards a remote peer.
- *
- * If the destination port is not open by any peer or the destination peer
- * does not accept the channel, #GNUNET_CADET_ChannelEndHandler will be called
- * for this channel.
- *
- * @param h cadet handle
- * @param channel_ctx client's channel context to associate with the channel
- * @param peer peer identity the channel should go to
- * @param port Port number.
- * @param options CadetOption flag field, with all desired option bits set to 1.
- *
- * @return handle to the channel
- */
- struct GNUNET_CADET_Channel *
- GNUNET_CADET_channel_create (struct GNUNET_CADET_Handle *h,
- void *channel_ctx,
- const struct GNUNET_PeerIdentity *peer,
- uint32_t port,
- enum GNUNET_CADET_ChannelOption options);
- /**
- * Destroy an existing channel.
- *
- * The existing end callback for the channel 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 channel Channel handle, becomes invalid after this call.
- */
- void
- GNUNET_CADET_channel_destroy (struct GNUNET_CADET_Channel *channel);
- /**
- * Struct to retrieve info about a channel.
- */
- union GNUNET_CADET_ChannelInfo
- {
- /**
- * #GNUNET_YES / #GNUNET_NO, for binary flags.
- */
- int yes_no;
- /**
- * Peer on the other side of the channel
- */
- const struct GNUNET_PeerIdentity peer;
- };
- /**
- * Get information about a channel.
- *
- * @param channel Channel handle.
- * @param option Query type GNUNET_CADET_OPTION_*
- * @param ... dependant on option, currently not used
- * @return Union with an answer to the query.
- */
- const union GNUNET_CADET_ChannelInfo *
- GNUNET_CADET_channel_get_info (struct GNUNET_CADET_Channel *channel,
- enum GNUNET_CADET_ChannelOption option, ...);
- /**
- * Handle for a transmission request.
- */
- struct GNUNET_CADET_TransmitHandle;
- /**
- * Ask the cadet to call @a notify once it is ready to transmit the
- * given number of bytes to the specified channel.
- * Only one call can be active at any time, to issue another request,
- * wait for the callback or cancel the current request.
- *
- * @param channel channel 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 @a 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, @a notify will NOT be called.
- */
- struct GNUNET_CADET_TransmitHandle *
- GNUNET_CADET_notify_transmit_ready (struct GNUNET_CADET_Channel *channel,
- 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_CADET_notify_transmit_ready_cancel (struct GNUNET_CADET_TransmitHandle *th);
- /**
- * Indicate readiness to receive the next message on a channel.
- *
- * Should only be called once per handler called.
- *
- * @param channel Channel that will be allowed to call another handler.
- */
- void
- GNUNET_CADET_receive_done (struct GNUNET_CADET_Channel *channel);
- /******************************************************************************/
- /******************** MONITORING /DEBUG API *************************/
- /******************************************************************************/
- /* The following calls are not useful for normal CADET operation, but for */
- /* debug and monitoring of the cadet 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 cadet applications. */
- /******************************************************************************/
- /**
- * Method called to retrieve information about a specific channel the cadet peer
- * is aware of, including all transit nodes.
- *
- * @param cls Closure.
- * @param root Root of the channel.
- * @param dest Destination of the channel.
- * @param port Destination port of the channel.
- * @param root_channel_number Local number for root, if known.
- * @param dest_channel_number Local number for dest, if known.
- * @param public_channel_numbe Number for P2P, always known.
- */
- typedef void
- (*GNUNET_CADET_ChannelCB) (void *cls,
- const struct GNUNET_PeerIdentity *root,
- const struct GNUNET_PeerIdentity *dest,
- uint32_t port,
- uint32_t root_channel_number,
- uint32_t dest_channel_number,
- uint32_t public_channel_number);
- /**
- * Method called to retrieve information about all peers in CADET, called
- * once per peer.
- *
- * After last peer has been reported, an additional call with NULL is done.
- *
- * @param cls Closure.
- * @param peer Peer, or NULL on "EOF".
- * @param tunnel Do we have a tunnel towards this peer?
- * @param n_paths Number of known paths towards this peer.
- * @param best_path How long is the best path?
- * (0 = unknown, 1 = ourselves, 2 = neighbor)
- */
- typedef void
- (*GNUNET_CADET_PeersCB) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- int tunnel,
- unsigned int n_paths,
- unsigned int best_path);
- /**
- * Method called to retrieve information about a specific peer
- * known to the service.
- *
- * @param cls Closure.
- * @param peer Peer ID.
- * @param tunnel Do we have a tunnel towards this peer? #GNUNET_YES/#GNUNET_NO
- * @param neighbor Is this a direct neighbor? #GNUNET_YES/#GNUNET_NO
- * @param n_paths Number of paths known towards peer.
- * @param paths Array of PEER_IDs representing all paths to reach the peer.
- * Each path starts with the first hop (local peer not included).
- * Each path ends with the destination peer (given in @c peer).
- */
- typedef void
- (*GNUNET_CADET_PeerCB) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- int tunnel,
- int neighbor,
- unsigned int n_paths,
- struct GNUNET_PeerIdentity *paths);
- /**
- * Method called to retrieve information about all tunnels in CADET, called
- * once per tunnel.
- *
- * After last tunnel has been reported, an additional call with NULL is done.
- *
- * @param cls Closure.
- * @param peer Destination peer, or NULL on "EOF".
- * @param channels Number of channels.
- * @param connections Number of connections.
- * @param estate Encryption state.
- * @param cstate Connectivity state.
- */
- typedef void
- (*GNUNET_CADET_TunnelsCB) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- unsigned int channels,
- unsigned int connections,
- uint16_t estate,
- uint16_t cstate);
- /**
- * Method called to retrieve information about a specific tunnel the cadet peer
- * has established, o`r is trying to establish.
- *
- * @param cls Closure.
- * @param peer Peer towards whom the tunnel is directed.
- * @param n_channels Number of channels.
- * @param n_connections Number of connections.
- * @param channels Channels.
- * @param connections Connections.
- * @param estate Encryption state.
- * @param cstate Connectivity state.
- */
- typedef void
- (*GNUNET_CADET_TunnelCB) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- unsigned int n_channels,
- unsigned int n_connections,
- uint32_t *channels,
- struct GNUNET_CADET_Hash *connections,
- unsigned int estate,
- unsigned int cstate);
- /**
- * Request information about a specific channel of the running cadet peer.
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h Handle to the cadet peer.
- * @param peer ID of the other end of the channel.
- * @param channel_number Channel number.
- * @param callback Function to call with the requested data.
- * @param callback_cls Closure for @c callback.
- */
- void
- GNUNET_CADET_get_channel (struct GNUNET_CADET_Handle *h,
- struct GNUNET_PeerIdentity *peer,
- uint32_t channel_number,
- GNUNET_CADET_ChannelCB callback,
- void *callback_cls);
- /**
- * Request a debug dump on the service's STDERR.
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h cadet handle
- */
- void
- GNUNET_CADET_request_dump (struct GNUNET_CADET_Handle *h);
- /**
- * Request information about peers known to the running cadet service.
- * The callback will be called for every peer known to the service.
- * Only one info request (of any kind) can be active at once.
- *
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h Handle to the cadet peer.
- * @param callback Function to call with the requested data.
- * @param callback_cls Closure for @c callback.
- *
- * @return #GNUNET_OK / #GNUNET_SYSERR
- */
- int
- GNUNET_CADET_get_peers (struct GNUNET_CADET_Handle *h,
- GNUNET_CADET_PeersCB callback,
- void *callback_cls);
- /**
- * Cancel a peer info request. The callback will not be called (anymore).
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h Cadet handle.
- *
- * @return Closure that was given to #GNUNET_CADET_get_peers().
- */
- void *
- GNUNET_CADET_get_peers_cancel (struct GNUNET_CADET_Handle *h);
- /**
- * Request information about a peer known to the running cadet peer.
- * The callback will be called for the tunnel once.
- * Only one info request (of any kind) can be active at once.
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h Handle to the cadet peer.
- * @param id Peer whose tunnel to examine.
- * @param callback Function to call with the requested data.
- * @param callback_cls Closure for @c callback.
- *
- * @return #GNUNET_OK / #GNUNET_SYSERR
- */
- int
- GNUNET_CADET_get_peer (struct GNUNET_CADET_Handle *h,
- const struct GNUNET_PeerIdentity *id,
- GNUNET_CADET_PeerCB callback,
- void *callback_cls);
- /**
- * Request information about tunnels of the running cadet peer.
- * The callback will be called for every tunnel of the service.
- * Only one info request (of any kind) can be active at once.
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h Handle to the cadet peer.
- * @param callback Function to call with the requested data.
- * @param callback_cls Closure for @c callback.
- *
- * @return #GNUNET_OK / #GNUNET_SYSERR
- */
- int
- GNUNET_CADET_get_tunnels (struct GNUNET_CADET_Handle *h,
- GNUNET_CADET_TunnelsCB callback,
- void *callback_cls);
- /**
- * Cancel a monitor request. The monitor callback will not be called.
- *
- * @param h Cadet handle.
- *
- * @return Closure given to #GNUNET_CADET_get_tunnels(), if any.
- */
- void *
- GNUNET_CADET_get_tunnels_cancel (struct GNUNET_CADET_Handle *h);
- /**
- * Request information about a tunnel of the running cadet peer.
- * The callback will be called for the tunnel once.
- * Only one info request (of any kind) can be active at once.
- *
- * WARNING: unstable API, likely to change in the future!
- *
- * @param h Handle to the cadet peer.
- * @param id Peer whose tunnel to examine.
- * @param callback Function to call with the requested data.
- * @param callback_cls Closure for @c callback.
- *
- * @return #GNUNET_OK / #GNUNET_SYSERR
- */
- int
- GNUNET_CADET_get_tunnel (struct GNUNET_CADET_Handle *h,
- const struct GNUNET_PeerIdentity *id,
- GNUNET_CADET_TunnelCB callback,
- void *callback_cls);
- /**
- * Create a message queue for a cadet channel.
- * The message queue can only be used to transmit messages,
- * not to receive them.
- *
- * @param channel the channel to create the message qeue for
- * @return a message queue to messages over the channel
- */
- struct GNUNET_MQ_Handle *
- GNUNET_CADET_mq_create (struct GNUNET_CADET_Channel *channel);
- #if 0 /* keep Emacsens' auto-indent happy */
- {
- #endif
- #ifdef __cplusplus
- }
- #endif
- /* ifndef GNUNET_CADET_SERVICE_H */
- #endif
- /** @} */ /* end of group */
- /* end of gnunet_cadet_service.h */
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