src/consensus/plugin_block_consensus.c

   1 /*
   2      This file is part of GNUnet
   3      Copyright (C) 2017 GNUnet e.V.
   4
   5      GNUnet is free software: you can redistribute it and/or modify it
   6      under the terms of the GNU Affero General Public License as published
   7      by the Free Software Foundation, either version 3 of the License,
   8      or (at your 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      Affero General Public License for more details.
  14
  15      You should have received a copy of the GNU Affero General Public License
  16      along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 /**
  20  * @file consensus/plugin_block_consensus.c
  21  * @brief consensus block, either nested block or marker
  22  * @author Christian Grothoff
  23  */
  24
  25 #include "platform.h"
  26 #include "consensus_protocol.h"
  27 #include "gnunet_block_plugin.h"
  28 #include "gnunet_block_group_lib.h"
  29
  30
  31 /**
  32  * Function called to validate a reply or a request.  For
  33  * request evaluation, simply pass "NULL" for the reply_block.
  34  *
  35  * @param cls closure
  36  * @param ctx context
  37  * @param type block type
  38  * @param group block group to use
  39  * @param eo control flags
  40  * @param query original query (hash)
  41  * @param xquery extrended query data (can be NULL, depending on type)
  42  * @param xquery_size number of bytes in xquery
  43  * @param reply_block response to validate
  44  * @param reply_block_size number of bytes in reply block
  45  * @return characterization of result
  46  */
  47 static enum GNUNET_BLOCK_EvaluationResult
  48 block_plugin_consensus_evaluate (void *cls,
  49                                  struct GNUNET_BLOCK_Context *ctx,
  50                                  enum GNUNET_BLOCK_Type type,
  51                                  struct GNUNET_BLOCK_Group *group,
  52                                  enum GNUNET_BLOCK_EvaluationOptions eo,
  53                                  const struct GNUNET_HashCode *query,
  54                                  const void *xquery,
  55                                  size_t xquery_size,
  56                                  const void *reply_block,
  57                                  size_t reply_block_size)
  58 {
  59   if (reply_block_size < sizeof (struct ConsensusElement))
  60     return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
  61
  62   const struct ConsensusElement *ce = reply_block;
  63
  64   if ( (0 != ce->marker) ||
  65        (0 == ce->payload_type ) )
  66     return GNUNET_BLOCK_EVALUATION_OK_MORE;
  67
  68   return GNUNET_BLOCK_evaluate (ctx,
  69                                 type,
  70                                 group,
  71                                 eo,
  72                                 query,
  73                                 xquery,
  74                                 xquery_size,
  75                                 &ce[1],
  76                                 reply_block_size - sizeof (struct ConsensusElement));
  77 }
  78
  79
  80 /**
  81  * Function called to obtain the key for a block.
  82  *
  83  * @param cls closure
  84  * @param type block type
  85  * @param block block to get the key for
  86  * @param block_size number of bytes in block
  87  * @param key set to the key (query) for the given block
  88  * @return #GNUNET_OK on success, #GNUNET_SYSERR if type not supported
  89  *         (or if extracting a key from a block of this type does not work)
  90  */
  91 static int
  92 block_plugin_consensus_get_key (void *cls,
  93                                enum GNUNET_BLOCK_Type type,
  94                                const void *block,
  95                                size_t block_size,
  96                                struct GNUNET_HashCode *key)
  97 {
  98   return GNUNET_SYSERR;
  99 }
 100
 101
 102 /**
 103  * Entry point for the plugin.
 104  */
 105 void *
 106 libgnunet_plugin_block_consensus_init (void *cls)
 107 {
 108   static enum GNUNET_BLOCK_Type types[] =
 109   {
 110     GNUNET_BLOCK_TYPE_CONSENSUS_ELEMENT,
 111     GNUNET_BLOCK_TYPE_ANY       /* end of list */
 112   };
 113   struct GNUNET_BLOCK_PluginFunctions *api;
 114
 115   api = GNUNET_new (struct GNUNET_BLOCK_PluginFunctions);
 116   api->evaluate = &block_plugin_consensus_evaluate;
 117   api->get_key = &block_plugin_consensus_get_key;
 118   api->types = types;
 119   return api;
 120 }
 121
 122
 123 /**
 124  * Exit point from the plugin.
 125  */
 126 void *
 127 libgnunet_plugin_block_consensus_done (void *cls)
 128 {
 129   struct GNUNET_BLOCK_PluginFunctions *api = cls;
 130
 131   GNUNET_free (api);
 132   return NULL;
 133 }
 134
 135 /* end of plugin_block_consensus.c */