src/include/gnunet_fragmentation_lib.h

   1 /*
   2      This file is part of GNUnet
   3      (C) 2009, 2011 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 3, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20 /**
  21  * @file include/gnunet_fragmentation_lib.h
  22  * @brief library to help fragment messages
  23  * @author Christian Grothoff
  24  *
  25  * TODO: consider additional flow-control for sending from
  26  *       fragmentation based on continuations.
  27  */
  28
  29 #ifndef GNUNET_FRAGMENTATION_LIB_H
  30 #define GNUNET_FRAGMENTATION_LIB_H
  31
  32 #include "gnunet_util_lib.h"
  33 #include "gnunet_bandwidth_lib.h"
  34 #include "gnunet_statistics_service.h"
  35
  36 #ifdef __cplusplus
  37 extern "C"
  38 {
  39 #if 0                           /* keep Emacsens' auto-indent happy */
  40 }
  41 #endif
  42 #endif
  43
  44
  45 /**
  46  * Fragmentation context.
  47  */
  48 struct GNUNET_FRAGMENT_Context;
  49
  50
  51 /**
  52  * Function that is called with messages created by the fragmentation
  53  * module.  In the case of the 'proc' callback of the
  54  * GNUNET_FRAGMENT_context_create function, this function must
  55  * eventually call 'GNUNET_FRAGMENT_context_transmission_done'.
  56  *
  57  * @param cls closure
  58  * @param msg the message that was created
  59  */
  60 typedef void (*GNUNET_FRAGMENT_MessageProcessor) (void *cls,
  61                                                   const struct
  62                                                   GNUNET_MessageHeader * msg);
  63
  64
  65 /**
  66  * Create a fragmentation context for the given message.
  67  * Fragments the message into fragments of size "mtu" or
  68  * less.  Calls 'proc' on each un-acknowledged fragment,
  69  * using both the expected 'delay' between messages and
  70  * acknowledgements and the given 'tracker' to guide the
  71  * frequency of calls to 'proc'.
  72  *
  73  * @param stats statistics context
  74  * @param mtu the maximum message size for each fragment
  75  * @param tracker bandwidth tracker to use for flow control (can be NULL)
  76  * @param delay expected delay between fragment transmission
  77  *              and ACK based on previous messages
  78  * @param msg the message to fragment
  79  * @param proc function to call for each fragment to transmit
  80  * @param proc_cls closure for proc
  81  * @return the fragmentation context
  82  */
  83 struct GNUNET_FRAGMENT_Context *GNUNET_FRAGMENT_context_create (struct
  84                                                                 GNUNET_STATISTICS_Handle
  85                                                                 *stats,
  86                                                                 uint16_t mtu,
  87                                                                 struct
  88                                                                 GNUNET_BANDWIDTH_Tracker
  89                                                                 *tracker,
  90                                                                 struct
  91                                                                 GNUNET_TIME_Relative
  92                                                                 delay,
  93                                                                 const struct
  94                                                                 GNUNET_MessageHeader
  95                                                                 *msg,
  96                                                                 GNUNET_FRAGMENT_MessageProcessor
  97                                                                 proc,
  98                                                                 void *proc_cls);
  99
 100
 101 /**
 102  * Continuation to call from the 'proc' function after the fragment
 103  * has been transmitted (and hence the next fragment can now be
 104  * given to proc).
 105  *
 106  * @param fc fragmentation context
 107  */
 108 void
 109 GNUNET_FRAGMENT_context_transmission_done (struct GNUNET_FRAGMENT_Context *fc);
 110
 111
 112 /**
 113  * Process an acknowledgement message we got from the other
 114  * side (to control re-transmits).
 115  *
 116  * @param fc fragmentation context
 117  * @param msg acknowledgement message we received
 118  * @return GNUNET_OK if this ack completes the work of the 'fc'
 119  *                   (all fragments have been received);
 120  *         GNUNET_NO if more messages are pending
 121  *         GNUNET_SYSERR if this ack is not valid for this fc
 122  */
 123 int GNUNET_FRAGMENT_process_ack (struct GNUNET_FRAGMENT_Context *fc,
 124                                  const struct GNUNET_MessageHeader *msg);
 125
 126
 127 /**
 128  * Destroy the given fragmentation context (stop calling 'proc', free
 129  * resources).
 130  *
 131  * @param fc fragmentation context
 132  * @return average delay between transmission and ACK for the
 133  *         last message, FOREVER if the message was not fully transmitted
 134  */
 135 struct GNUNET_TIME_Relative
 136 GNUNET_FRAGMENT_context_destroy (struct GNUNET_FRAGMENT_Context *fc);
 137
 138
 139 /**
 140  * Defragmentation context (one per connection).
 141  */
 142 struct GNUNET_DEFRAGMENT_Context;
 143
 144
 145 /**
 146  * Function that is called with acknowledgement messages created by
 147  * the fragmentation module.  Acknowledgements are cummulative,
 148  * so it is OK to only transmit the 'latest' ack message for the same
 149  * message ID.
 150  *
 151  * @param cls closure
 152  * @param id unique message ID (modulo collisions)
 153  * @param msg the message that was created
 154  */
 155 typedef void (*GNUNET_DEFRAGMENT_AckProcessor) (void *cls,
 156                                                 uint32_t id,
 157                                                 const struct
 158                                                 GNUNET_MessageHeader * msg);
 159
 160
 161 /**
 162  * Create a defragmentation context.
 163  *
 164  * @param stats statistics context
 165  * @param mtu the maximum message size for each fragment
 166  * @param num_msgs how many fragmented messages
 167  *                 to we defragment at most at the same time?
 168  * @param cls closure for proc and ackp
 169  * @param proc function to call with defragmented messages
 170  * @param ackp function to call with acknowledgements (to send
 171  *             back to the other side)
 172  * @return the defragmentation context
 173  */
 174 struct GNUNET_DEFRAGMENT_Context *GNUNET_DEFRAGMENT_context_create (struct
 175                                                                     GNUNET_STATISTICS_Handle
 176                                                                     *stats,
 177                                                                     uint16_t
 178                                                                     mtu,
 179                                                                     unsigned int
 180                                                                     num_msgs,
 181                                                                     void *cls,
 182                                                                     GNUNET_FRAGMENT_MessageProcessor
 183                                                                     proc,
 184                                                                     GNUNET_DEFRAGMENT_AckProcessor
 185                                                                     ackp);
 186
 187
 188 /**
 189  * Destroy the given defragmentation context.
 190  *
 191  * @param dc defragmentation context
 192  */
 193 void GNUNET_DEFRAGMENT_context_destroy (struct GNUNET_DEFRAGMENT_Context *dc);
 194
 195
 196 /**
 197  * We have received a fragment.  Process it.
 198  *
 199  * @param dc the context
 200  * @param msg the message that was received
 201  * @return GNUNET_OK on success, GNUNET_NO if this was a duplicate, GNUNET_SYSERR on error
 202  */
 203 int
 204 GNUNET_DEFRAGMENT_process_fragment (struct GNUNET_DEFRAGMENT_Context *dc,
 205                                     const struct GNUNET_MessageHeader *msg);
 206
 207
 208 #if 0                           /* keep Emacsens' auto-indent happy */
 209 {
 210 #endif
 211 #ifdef __cplusplus
 212 }
 213 #endif
 214
 215 /* end of gnunet_fragmentation_lib.h */
 216 #endif