src/include/gnunet_block_plugin.h

   1 /*
   2      This file is part of GNUnet
   3      (C) 2010 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 /**
  22  * @file include/gnunet_block_plugin.h
  23  * @brief API for block plugins.  Each block plugin must conform to
  24  *        the API specified by this header.
  25  * @author Christian Grothoff
  26  */
  27 #ifndef PLUGIN_BLOCK_H
  28 #define PLUGIN_BLOCK_H
  29
  30 #include "gnunet_util_lib.h"
  31 #include "gnunet_container_lib.h"
  32 #include "gnunet_block_lib.h"
  33
  34
  35 /**
  36  * Function called to validate a reply or a request.  For
  37  * request evaluation, simply pass "NULL" for the reply_block.
  38  * Note that it is assumed that the reply has already been
  39  * matched to the key (and signatures checked) as it would
  40  * be done with the "get_key" function.
  41  *
  42  * @param cls closure
  43  * @param type block type
  44  * @param query original query (hash)
  45  * @param bf pointer to bloom filter associated with query; possibly updated (!)
  46  * @param bf_mutator mutation value for bf
  47  * @param xquery extrended query data (can be NULL, depending on type)
  48  * @param xquery_size number of bytes in xquery
  49  * @param reply_block response to validate
  50  * @param reply_block_size number of bytes in reply block
  51  * @return characterization of result
  52  */
  53 typedef enum
  54     GNUNET_BLOCK_EvaluationResult (*GNUNET_BLOCK_EvaluationFunction) (void *cls,
  55                                                                       enum
  56                                                                       GNUNET_BLOCK_Type
  57                                                                       type,
  58                                                                       const
  59                                                                       GNUNET_HashCode
  60                                                                       * query,
  61                                                                       struct
  62                                                                       GNUNET_CONTAINER_BloomFilter
  63                                                                       ** bf,
  64                                                                       int32_t
  65                                                                       bf_mutator,
  66                                                                       const void
  67                                                                       *xquery,
  68                                                                       size_t
  69                                                                       xquery_size,
  70                                                                       const void
  71                                                                       *reply_block,
  72                                                                       size_t
  73                                                                       reply_block_size);
  74
  75
  76 /**
  77  * Function called to obtain the key for a block.
  78  *
  79  * @param cls closure
  80  * @param type block type
  81  * @param block block to get the key for
  82  * @param block_size number of bytes in block
  83  * @param key set to the key (query) for the given block
  84  * @return GNUNET_YES on success,
  85  *         GNUNET_NO if the block is malformed
  86  *         GNUNET_SYSERR if type not supported
  87  *         (or if extracting a key from a block of this type does not work)
  88  */
  89 typedef int (*GNUNET_BLOCK_GetKeyFunction) (void *cls,
  90                                             enum GNUNET_BLOCK_Type type,
  91                                             const void *block,
  92                                             size_t block_size,
  93                                             GNUNET_HashCode * key);
  94
  95
  96
  97 /**
  98  * Each plugin is required to return a pointer to a struct of this
  99  * type as the return value from its entry point.
 100  */
 101 struct GNUNET_BLOCK_PluginFunctions
 102 {
 103
 104   /**
 105    * Closure for all of the callbacks.
 106    */
 107   void *cls;
 108
 109   /**
 110    * 0-terminated array of block types supported by this plugin.
 111    */
 112   const enum GNUNET_BLOCK_Type *types;
 113
 114   /**
 115    * Main function of a block plugin.  Allows us to check if a
 116    * block matches a query.
 117    */
 118   GNUNET_BLOCK_EvaluationFunction evaluate;
 119
 120   /**
 121    * Obtain the key for a given block (if possible).
 122    */
 123   GNUNET_BLOCK_GetKeyFunction get_key;
 124
 125 };
 126
 127
 128 #endif