/* This file is part of GNUnet Copyright (C) 2009, 2011, 2015 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 . */ /** * @author Christian Grothoff * * @file * Library to help fragment messages * * @defgroup fragmentation Fragmentation library * Library to help fragment messages * @{ * * @todo Consider additional flow-control for sending from * fragmentation based on continuations. */ #ifndef GNUNET_FRAGMENTATION_LIB_H #define GNUNET_FRAGMENTATION_LIB_H #include "gnunet_util_lib.h" #include "gnunet_bandwidth_lib.h" #include "gnunet_statistics_service.h" #ifdef __cplusplus extern "C" { #if 0 /* keep Emacsens' auto-indent happy */ } #endif #endif /** * Fragmentation context. */ struct GNUNET_FRAGMENT_Context; /** * Function that is called with messages created by the fragmentation * module. In the case of the 'proc' callback of the * #GNUNET_FRAGMENT_context_create() function, this function must * eventually call #GNUNET_FRAGMENT_context_transmission_done(). * * @param cls closure * @param msg the message that was created */ typedef void (*GNUNET_FRAGMENT_MessageProcessor) (void *cls, const struct GNUNET_MessageHeader *msg); /** * Create a fragmentation context for the given message. * Fragments the message into fragments of size @a mtu or * less. Calls @a proc on each un-acknowledged fragment, * using both the expected @a msg_delay between messages and * acknowledgements and the given @a tracker to guide the * frequency of calls to @a proc. * * @param stats statistics context * @param mtu the maximum message size for each fragment * @param tracker bandwidth tracker to use for flow control (can be NULL) * @param msg_delay initial delay to insert between fragment transmissions * based on previous messages * @param ack_delay expected delay between fragment transmission * and ACK based on previous messages * @param msg the message to fragment * @param proc function to call for each fragment to transmit * @param proc_cls closure for proc * @return the fragmentation context */ struct GNUNET_FRAGMENT_Context * GNUNET_FRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats, uint16_t mtu, struct GNUNET_BANDWIDTH_Tracker *tracker, struct GNUNET_TIME_Relative msg_delay, struct GNUNET_TIME_Relative ack_delay, const struct GNUNET_MessageHeader *msg, GNUNET_FRAGMENT_MessageProcessor proc, void *proc_cls); /** * Continuation to call from the 'proc' function after the fragment * has been transmitted (and hence the next fragment can now be * given to proc). * * @param fc fragmentation context */ void GNUNET_FRAGMENT_context_transmission_done (struct GNUNET_FRAGMENT_Context *fc); /** * Process an acknowledgement message we got from the other * side (to control re-transmits). * * @param fc fragmentation context * @param msg acknowledgement message we received * @return #GNUNET_OK if this ack completes the work of the 'fc' * (all fragments have been received); * #GNUNET_NO if more messages are pending * #GNUNET_SYSERR if this ack is not valid for this fc */ int GNUNET_FRAGMENT_process_ack (struct GNUNET_FRAGMENT_Context *fc, const struct GNUNET_MessageHeader *msg); /** * Destroy the given fragmentation context (stop calling 'proc', free * resources). * * @param fc fragmentation context * @param msg_delay where to store average delay between individual message transmissions the * last message (OUT only) * @param ack_delay where to store average delay between transmission and ACK for the * last message, set to FOREVER if the message was not fully transmitted (OUT only) */ void GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *fc, struct GNUNET_TIME_Relative *msg_delay, struct GNUNET_TIME_Relative *ack_delay); /** * Convert an ACK message to a printable format suitable for logging. * * @param ack message to print * @return ack in human-readable format */ const char * GNUNET_FRAGMENT_print_ack (const struct GNUNET_MessageHeader *ack); /** * Defragmentation context (one per connection). */ struct GNUNET_DEFRAGMENT_Context; /** * Function that is called with acknowledgement messages created by * the fragmentation module. Acknowledgements are cummulative, * so it is OK to only transmit the 'latest' ack message for the same * message ID. * * @param cls closure * @param id unique message ID (modulo collisions) * @param msg the message that was created */ typedef void (*GNUNET_DEFRAGMENT_AckProcessor) (void *cls, uint32_t id, const struct GNUNET_MessageHeader *msg); /** * Create a defragmentation context. * * @param stats statistics context * @param mtu the maximum message size for each fragment * @param num_msgs how many fragmented messages * to we defragment at most at the same time? * @param cls closure for @a proc and @a ackp * @param proc function to call with defragmented messages * @param ackp function to call with acknowledgements (to send * back to the other side) * @return the defragmentation context */ struct GNUNET_DEFRAGMENT_Context * GNUNET_DEFRAGMENT_context_create (struct GNUNET_STATISTICS_Handle *stats, uint16_t mtu, unsigned int num_msgs, void *cls, GNUNET_FRAGMENT_MessageProcessor proc, GNUNET_DEFRAGMENT_AckProcessor ackp); /** * Destroy the given defragmentation context. * * @param dc defragmentation context */ void GNUNET_DEFRAGMENT_context_destroy (struct GNUNET_DEFRAGMENT_Context *dc); /** * We have received a fragment. Process it. * * @param dc the context * @param msg the message that was received * @return #GNUNET_OK on success, * #GNUNET_NO if this was a duplicate, * #GNUNET_SYSERR on error */ int GNUNET_DEFRAGMENT_process_fragment (struct GNUNET_DEFRAGMENT_Context *dc, const struct GNUNET_MessageHeader *msg); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif #endif /** @} */ /* end of group */