diff options
Diffstat (limited to 'src/dns/plugin_block_dns.c')
| -rw-r--r-- | src/dns/plugin_block_dns.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/dns/plugin_block_dns.c b/src/dns/plugin_block_dns.c new file mode 100644 index 0000000..96a4dc0 --- /dev/null +++ b/src/dns/plugin_block_dns.c @@ -0,0 +1,170 @@ +/* + 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 dns/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 */ |