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- /*
- This file is part of GNUnet.
- Copyright (C) 2001-2017 GNUnet e.V.
- GNUnet is free software: you can redistribute it and/or modify it
- under the terms of the GNU Affero General Public License as published
- by the Free Software Foundation, either version 3 of the License,
- 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
- Affero General Public License for more details.
- You should have received a copy of the GNU Affero General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- SPDX-License-Identifier: AGPL3.0-or-later
- */
- /**
- * @file cadet/gnunet-service-cadet_connection.h
- * @brief A connection is a live end-to-end messaging mechanism
- * where the peers are identified by a path and know how
- * to forward along the route using a connection identifier
- * for routing the data.
- * @author Bartlomiej Polot
- * @author Christian Grothoff
- */
- #ifndef GNUNET_SERVICE_CADET_CONNECTION_H
- #define GNUNET_SERVICE_CADET_CONNECTION_H
- #include "gnunet_util_lib.h"
- #include "gnunet-service-cadet.h"
- #include "gnunet-service-cadet_peer.h"
- #include "cadet_protocol.h"
- /**
- * Function called to notify tunnel about change in our readyness.
- *
- * @param cls closure
- * @param is_ready #GNUNET_YES if the connection is now ready for transmission,
- * #GNUNET_NO if the connection is no longer ready for transmission
- */
- typedef void
- (*GCC_ReadyCallback)(void *cls,
- int is_ready);
- /**
- * Destroy a connection, called when the CORE layer is already done
- * (i.e. has received a BROKEN message), but if we still have to
- * communicate the destruction of the connection to the tunnel (if one
- * exists).
- *
- * @param cc connection to destroy
- */
- void
- GCC_destroy_without_core(struct CadetConnection *cc);
- /**
- * Destroy a connection, called if the tunnel association with the
- * connection was already broken, but we still need to notify the CORE
- * layer about the breakage.
- *
- * @param cc connection to destroy
- */
- void
- GCC_destroy_without_tunnel(struct CadetConnection *cc);
- /**
- * Lookup a connection by its identifier.
- *
- * @param cid identifier to resolve
- * @return NULL if connection was not found
- */
- struct CadetConnection *
- GCC_lookup(const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid);
- /**
- * Create a connection to @a destination via @a path and
- * notify @a cb whenever we are ready for more data.
- *
- * @param destination where to go
- * @param path which path to take (may not be the full path)
- * @param off offset of @a destination on @a path
- * @param ct which tunnel uses this connection
- * @param ready_cb function to call when ready to transmit
- * @param ready_cb_cls closure for @a cb
- * @return handle to the connection
- */
- struct CadetConnection *
- GCC_create(struct CadetPeer *destination,
- struct CadetPeerPath *path,
- unsigned int off,
- struct CadetTConnection *ct,
- GCC_ReadyCallback ready_cb,
- void *ready_cb_cls);
- /**
- * Create a connection to @a destination via @a path and
- * notify @a cb whenever we are ready for more data. This
- * is an inbound tunnel, so we must use the existing @a cid
- *
- * @param destination where to go
- * @param path which path to take (may not be the full path)
- * @param ct which tunnel uses this connection
- * @param ready_cb function to call when ready to transmit
- * @param ready_cb_cls closure for @a cb
- * @return handle to the connection, NULL if we already have
- * a connection that takes precedence on @a path
- */
- struct CadetConnection *
- GCC_create_inbound(struct CadetPeer *destination,
- struct CadetPeerPath *path,
- struct CadetTConnection *ct,
- const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid,
- GCC_ReadyCallback ready_cb,
- void *ready_cb_cls);
- /**
- * Transmit message @a msg via connection @a cc. Must only be called
- * (once) after the connection has signalled that it is ready via the
- * `ready_cb`. Clients can also use #GCC_is_ready() to check if the
- * connection is right now ready for transmission.
- *
- * @param cc connection identification
- * @param env envelope with message to transmit;
- * the #GNUNET_MQ_notify_send() must not have yet been used
- * for the envelope. Also, the message better match the
- * connection identifier of this connection...
- */
- void
- GCC_transmit(struct CadetConnection *cc,
- struct GNUNET_MQ_Envelope *env);
- /**
- * A CREATE_ACK was received for this connection, process it.
- *
- * @param cc the connection that got the ACK.
- */
- void
- GCC_handle_connection_create_ack(struct CadetConnection *cc);
- /**
- * We got a #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE for a
- * connection that we already have. Either our ACK got lost
- * or something is fishy. Consider retransmitting the ACK.
- *
- * @param cc connection that got the duplicate CREATE
- */
- void
- GCC_handle_duplicate_create(struct CadetConnection *cc);
- /**
- * Handle KX message.
- *
- * @param cc connection that received encrypted message
- * @param msg the key exchange message
- */
- void
- GCC_handle_kx(struct CadetConnection *cc,
- const struct GNUNET_CADET_TunnelKeyExchangeMessage *msg);
- /**
- * Handle KX_AUTH message.
- *
- * @param cc connection that received encrypted message
- * @param msg the key exchange message
- */
- void
- GCC_handle_kx_auth(struct CadetConnection *cc,
- const struct GNUNET_CADET_TunnelKeyExchangeAuthMessage *msg);
- /**
- * Performance metrics for a connection.
- */
- struct CadetConnectionMetrics {
- /**
- * Our current best estimate of the latency, based on a weighted
- * average of at least @a latency_datapoints values.
- */
- struct GNUNET_TIME_Relative aged_latency;
- /**
- * When was this connection first established? (by us sending or
- * receiving the CREATE_ACK for the first time)
- */
- struct GNUNET_TIME_Absolute age;
- /**
- * When was this connection last used? (by us sending or
- * receiving a PAYLOAD message on it)
- */
- struct GNUNET_TIME_Absolute last_use;
- /**
- * How many packets that ought to generate an ACK did we send via
- * this connection?
- */
- unsigned long long num_acked_transmissions;
- /**
- * Number of packets that were sent via this connection did actually
- * receive an ACK? (Note: ACKs may be transmitted and lost via
- * other connections, so this value should only be interpreted
- * relative to @e num_acked_transmissions and in relation to other
- * connections.)
- */
- unsigned long long num_successes;
- };
- /**
- * Obtain performance @a metrics from @a cc.
- *
- * @param cc connection to query
- * @return the metrics
- */
- const struct CadetConnectionMetrics *
- GCC_get_metrics(struct CadetConnection *cc);
- /**
- * Handle encrypted message.
- *
- * @param cc connection that received encrypted message
- * @param msg the encrypted message to decrypt
- */
- void
- GCC_handle_encrypted(struct CadetConnection *cc,
- const struct GNUNET_CADET_TunnelEncryptedMessage *msg);
- /**
- * We sent a message for which we expect to receive an ACK via
- * the connection identified by @a cti.
- *
- * @param cid connection identifier where we expect an ACK
- */
- void
- GCC_ack_expected(const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid);
- /**
- * We observed an ACK for a message that was originally sent via
- * the connection identified by @a cti.
- *
- * @param cid connection identifier where we got an ACK for a message
- * that was originally sent via this connection (the ACK
- * may have gotten back to us via a different connection).
- */
- void
- GCC_ack_observed(const struct GNUNET_CADET_ConnectionTunnelIdentifier *cid);
- /**
- * We observed some the given @a latency on the connection
- * identified by @a cti. (The same connection was taken
- * in both directions.)
- *
- * @param cti connection identifier where we measured latency
- * @param latency the observed latency
- */
- void
- GCC_latency_observed(const struct GNUNET_CADET_ConnectionTunnelIdentifier *cti,
- struct GNUNET_TIME_Relative latency);
- /**
- * Return the tunnel associated with this connection.
- *
- * @param cc connection to query
- * @return corresponding entry in the tunnel's connection list
- */
- struct CadetTConnection *
- GCC_get_ct(struct CadetConnection *cc);
- /**
- * Obtain the path used by this connection.
- *
- * @param cc connection
- * @param off[out] set to offset in this path where the connection @a cc ends
- * @return path to @a cc
- */
- struct CadetPeerPath *
- GCC_get_path(struct CadetConnection *cc,
- unsigned int *off);
- /**
- * Obtain unique ID for the connection.
- *
- * @param cc connection.
- * @return unique number of the connection
- */
- const struct GNUNET_CADET_ConnectionTunnelIdentifier *
- GCC_get_id(struct CadetConnection *cc);
- /**
- * Get a (static) string for a connection.
- *
- * @param cc Connection.
- */
- const char *
- GCC_2s(const struct CadetConnection *cc);
- /**
- * Log connection info.
- *
- * @param cc connection
- * @param level Debug level to use.
- */
- void
- GCC_debug(struct CadetConnection *cc,
- enum GNUNET_ErrorType level);
- #endif
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