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/*
This file is part of GNUnet
(C) 2010 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 3, 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @file block/plugin_block_dns.c
* @brief block plugin for storing .gnunet-bindings
* @author Philipp Tölke
*/
#include "platform.h"
#include "gnunet_block_plugin.h"
#include "block_dns.h"
#include "gnunet_signatures.h"
#define DEBUG_DHT GNUNET_EXTRA_LOGGING
/**
* Function called to validate a reply or a request. For
* request evaluation, simply pass "NULL" for the reply_block.
*
* @param cls closure
* @param type block type
* @param query original query (hash)
* @param bf pointer to bloom filter associated with query; possibly updated (!)
* @param bf_mutator mutation value for bf
* @param xquery extended query data (can be NULL, depending on type)
* @param xquery_size number of bytes in xquery
* @param reply_block response to validate
* @param reply_block_size number of bytes in reply block
* @return characterization of result
*/
static enum GNUNET_BLOCK_EvaluationResult
block_plugin_dns_evaluate (void *cls, enum GNUNET_BLOCK_Type type,
const GNUNET_HashCode * query,
struct GNUNET_CONTAINER_BloomFilter **bf,
int32_t bf_mutator, const void *xquery,
size_t xquery_size, const void *reply_block,
size_t reply_block_size)
{
switch (type)
{
case GNUNET_BLOCK_TYPE_DNS:
if (xquery_size != 0)
return GNUNET_BLOCK_EVALUATION_REQUEST_INVALID;
if (reply_block_size == 0)
return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
if (reply_block_size != sizeof (struct GNUNET_DNS_Record))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"DNS-Block is invalid: reply_block_size=%d != %d\n",
reply_block_size, sizeof (struct GNUNET_DNS_Record));
return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
}
const struct GNUNET_DNS_Record *rec = reply_block;
if (ntohl (rec->purpose.size) !=
sizeof (struct GNUNET_DNS_Record) -
sizeof (struct GNUNET_CRYPTO_RsaSignature))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"DNS-Block is invalid: rec->purpose.size=%d != %d\n",
ntohl (rec->purpose.size),
sizeof (struct GNUNET_DNS_Record) -
sizeof (struct GNUNET_CRYPTO_RsaSignature));
return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
}
if (GNUNET_TIME_relative_get_zero ().rel_value ==
GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (rec->expiration_time)).rel_value)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "DNS-Block is invalid: Timeout\n");
return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
}
if (GNUNET_OK !=
GNUNET_CRYPTO_rsa_verify (htonl (GNUNET_SIGNATURE_PURPOSE_DNS_RECORD),
&rec->purpose, &rec->signature, &rec->peer))
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"DNS-Block is invalid: invalid signature\n");
return GNUNET_BLOCK_EVALUATION_RESULT_INVALID;
}
/* How to decide whether there are no more? */
return GNUNET_BLOCK_EVALUATION_OK_MORE;
default:
return GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED;
}
}
/**
* Function called to obtain the key for a block.
*
* @param cls closure
* @param type block type
* @param block block to get the key for
* @param block_size number of bytes in block
* @param key set to the key (query) for the given block
* @return GNUNET_OK on success, GNUNET_SYSERR if type not supported
* (or if extracting a key from a block of this type does not work)
*/
static int
block_plugin_dns_get_key (void *cls, enum GNUNET_BLOCK_Type type,
const void *block, size_t block_size,
GNUNET_HashCode * key)
{
if (type != GNUNET_BLOCK_TYPE_DNS)
return GNUNET_SYSERR;
const struct GNUNET_DNS_Record *rec = block;
memcpy (key, &rec->service_descriptor, sizeof (GNUNET_HashCode));
return GNUNET_OK;
}
/**
* Entry point for the plugin.
*/
void *
libgnunet_plugin_block_dns_init (void *cls)
{
static enum GNUNET_BLOCK_Type types[] =
{
GNUNET_BLOCK_TYPE_DNS,
GNUNET_BLOCK_TYPE_ANY /* end of list */
};
struct GNUNET_BLOCK_PluginFunctions *api;
api = GNUNET_malloc (sizeof (struct GNUNET_BLOCK_PluginFunctions));
api->evaluate = &block_plugin_dns_evaluate;
api->get_key = &block_plugin_dns_get_key;
api->types = types;
return api;
}
/**
* Exit point from the plugin.
*/
void *
libgnunet_plugin_block_dns_done (void *cls)
{
struct GNUNET_TRANSPORT_PluginFunctions *api = cls;
GNUNET_free (api);
return NULL;
}
/* end of plugin_block_dns.c */
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