/* This file is part of GNUnet. (C) 2009, 2010, 2011 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. */ /** * * TODO: * - Write xquery and block plugin * - The smaller FIXME issues all around * * @file gns/gnunet-service-gns.c * @brief GNUnet GNS service * @author Martin Schanzenbach */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_transport_service.h" #include "gnunet_dns_service.h" #include "gnunet_dnsparser_lib.h" #include "gnunet_dht_service.h" #include "gnunet_namestore_service.h" #include "gnunet_gns_service.h" #include "block_gns.h" #include "gns.h" #define DHT_OPERATION_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5) #define DHT_LOOKUP_TIMEOUT DHT_OPERATION_TIMEOUT #define DHT_GNS_REPLICATION_LEVEL 5 /* Ignore for now not used anyway and probably never will */ #define GNUNET_MESSAGE_TYPE_GNS_CLIENT_LOOKUP 23 #define GNUNET_MESSAGE_TYPE_GNS_CLIENT_RESULT 24 /** * Handle to a currenty pending resolution */ struct GNUNET_GNS_ResolverHandle { /* The name to resolve */ char *name; /* the request handle to reply to */ struct GNUNET_DNS_RequestHandle *request_handle; /* the dns parser packet received */ struct GNUNET_DNSPARSER_Packet *packet; /* the query parsed from the packet */ struct GNUNET_DNSPARSER_Query *query; /* has this query been answered? how many matches */ int answered; /* the authoritative zone to query */ GNUNET_HashCode authority; /* the name of the authoritative zone to query */ char *authority_name; /** * we have an authority in namestore that * may be able to resolve */ int authority_found; /* a handle for dht lookups. should be NULL if no lookups are in progress */ struct GNUNET_DHT_GetHandle *get_handle; /* timeout task for dht lookups */ GNUNET_SCHEDULER_TaskIdentifier dht_timeout_task; }; /** * Our handle to the DNS handler library */ struct GNUNET_DNS_Handle *dns_handle; /** * Our handle to the DHT */ struct GNUNET_DHT_Handle *dht_handle; /** * Our zone's private key */ struct GNUNET_CRYPTO_RsaPrivateKey *zone_key; /** * Our handle to the namestore service * FIXME maybe need a second handle for iteration */ struct GNUNET_NAMESTORE_Handle *namestore_handle; /** * Handle to iterate over our authoritative zone in namestore */ struct GNUNET_NAMESTORE_ZoneIterator *namestore_iter; /** * The configuration the GNS service is running with */ const struct GNUNET_CONFIGURATION_Handle *GNS_cfg; /** * Our notification context. */ static struct GNUNET_SERVER_NotificationContext *nc; /** * Our zone hash */ GNUNET_HashCode zone_hash; /** * Our tld. Maybe get from config file */ const char* gnunet_tld = ".gnunet"; /** * Useful for zone update for DHT put */ static int num_public_records = 3600; struct GNUNET_TIME_Relative dht_update_interval; GNUNET_SCHEDULER_TaskIdentifier zone_update_taskid = GNUNET_SCHEDULER_NO_TASK; /* Prototypes */ static void reply_to_dns(struct GNUNET_GNS_ResolverHandle *answer, uint32_t rd_count, const struct GNUNET_NAMESTORE_RecordData *rd); static void resolve_name(struct GNUNET_GNS_ResolverHandle *rh); /** * Task run during shutdown. * * @param cls unused * @param tc unused */ static void shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { /* Kill zone task for it may make the scheduler hang */ if (zone_update_taskid) GNUNET_SCHEDULER_cancel(zone_update_taskid); GNUNET_DNS_disconnect(dns_handle); GNUNET_NAMESTORE_disconnect(namestore_handle, 1); GNUNET_DHT_disconnect(dht_handle); } /** * Callback when record data is put into namestore * * @param cls the closure * @param success GNUNET_OK on success * @param emsg the error message. NULL if SUCCESS==GNUNET_OK */ void on_namestore_record_put_result(void *cls, int32_t success, const char *emsg) { if (GNUNET_NO == success) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "records already in namestore\n"); return; } else if (GNUNET_YES == success) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "records successfully put in namestore\n"); return; } GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Error putting records into namestore: %s\n", emsg); } /** * Handle timeout for DHT requests * * @param cls the request handle as closure * @param tc the task context */ static void dht_lookup_timeout(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_GNS_ResolverHandle *rh = cls; GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "dht lookup for query %s (type=%d) timed out.\n", rh->name, rh->query->type); GNUNET_DHT_get_stop (rh->get_handle); reply_to_dns(rh, 0, NULL); } /** * Function called when we get a result from the dht * for our query * * @param cls the request handle * @param exp lifetime * @param key the key the record was stored under * @param get_path get path * @param get_path_length get path length * @param put_path put path * @param put_path_length put path length * @param type the block type * @param size the size of the record * @param data the record data */ static void process_authority_dht_result(void* cls, struct GNUNET_TIME_Absolute exp, const GNUNET_HashCode * key, const struct GNUNET_PeerIdentity *get_path, unsigned int get_path_length, const struct GNUNET_PeerIdentity *put_path, unsigned int put_path_length, enum GNUNET_BLOCK_Type type, size_t size, const void *data) { struct GNUNET_GNS_ResolverHandle *rh; struct GNSNameRecordBlock *nrb; uint32_t num_records; char* name = NULL; char* rd_data = (char*) data; int i; int rd_size; GNUNET_HashCode zone, name_hash; if (data == NULL) return; //FIXME check expiration? rh = (struct GNUNET_GNS_ResolverHandle *)cls; nrb = (struct GNSNameRecordBlock*)data; /* stop dht lookup and timeout task */ GNUNET_DHT_get_stop (rh->get_handle); GNUNET_SCHEDULER_cancel(rh->dht_timeout_task); rh->get_handle = NULL; num_records = ntohl(nrb->rd_count); name = (char*)&nrb[1]; { struct GNUNET_NAMESTORE_RecordData rd[num_records]; rd_data += strlen(name) + 1 + sizeof(struct GNSNameRecordBlock); rd_size = size - strlen(name) - 1 - sizeof(struct GNSNameRecordBlock); if (GNUNET_SYSERR == GNUNET_NAMESTORE_records_deserialize (rd_size, rd_data, num_records, rd)) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Error deserializing data!\n"); return; } GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got name: %s (wanted %s)\n", name, rh->authority_name); for (i=0; iauthority_name); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got type: %d (wanted %d)\n", rd[i].record_type, GNUNET_GNS_RECORD_PKEY); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got data length: %d\n", rd[i].data_size); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got flag %d\n", rd[i].flags); if ((strcmp(name, rh->authority_name) == 0) && (rd[i].record_type == GNUNET_GNS_RECORD_PKEY)) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Authority found in DHT\n"); rh->answered = 1; GNUNET_CRYPTO_hash( (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *)rd[i].data, rd[i].data_size, &rh->authority); } } GNUNET_CRYPTO_hash(name, strlen(name), &name_hash); GNUNET_CRYPTO_hash_xor(key, &name_hash, &zone); /* Save to namestore */ if (0 == GNUNET_CRYPTO_hash_cmp(&zone_hash, &zone)) { GNUNET_NAMESTORE_record_put (namestore_handle, &nrb->public_key, name, exp, num_records, rd, &nrb->signature, &on_namestore_record_put_result, //cont NULL); //cls } } if (rh->answered) { rh->answered = 0; resolve_name(rh); return; } GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "No authority in records\n"); reply_to_dns(rh, 0, NULL); } /** * Start DHT lookup for a name -> PKEY (compare NS) record in * query->authority's zone * * @param rh the pending gns query * @param name the name of the PKEY record */ static void resolve_authority_dht(struct GNUNET_GNS_ResolverHandle *rh) { uint32_t xquery; GNUNET_HashCode name_hash; GNUNET_HashCode lookup_key; GNUNET_CRYPTO_hash(rh->authority_name, strlen(rh->authority_name), &name_hash); GNUNET_CRYPTO_hash_xor(&name_hash, &rh->authority, &lookup_key); rh->dht_timeout_task = GNUNET_SCHEDULER_add_delayed (DHT_LOOKUP_TIMEOUT, &dht_lookup_timeout, rh); xquery = htonl(GNUNET_GNS_RECORD_PKEY); //FIXME how long to wait for results? rh->get_handle = GNUNET_DHT_get_start(dht_handle, DHT_OPERATION_TIMEOUT, GNUNET_BLOCK_TYPE_GNS_NAMERECORD, &lookup_key, DHT_GNS_REPLICATION_LEVEL, GNUNET_DHT_RO_NONE, &xquery, sizeof(xquery), &process_authority_dht_result, rh); } /** * Function called when we get a result from the dht * for our query * * @param cls the request handle * @param exp lifetime * @param key the key the record was stored under * @param get_path get path * @param get_path_length get path length * @param put_path put path * @param put_path_length put path length * @param type the block type * @param size the size of the record * @param data the record data */ static void process_name_dht_result(void* cls, struct GNUNET_TIME_Absolute exp, const GNUNET_HashCode * key, const struct GNUNET_PeerIdentity *get_path, unsigned int get_path_length, const struct GNUNET_PeerIdentity *put_path, unsigned int put_path_length, enum GNUNET_BLOCK_Type type, size_t size, const void *data) { struct GNUNET_GNS_ResolverHandle *rh; struct GNSNameRecordBlock *nrb; uint32_t num_records; char* name = NULL; char* rd_data = (char*)data; int i; int rd_size; GNUNET_HashCode zone, name_hash; GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "got dht result (size=%d)\n", size); if (data == NULL) return; //FIXME maybe check expiration here, check block type rh = (struct GNUNET_GNS_ResolverHandle *)cls; nrb = (struct GNSNameRecordBlock*)data; /* stop lookup and timeout task */ GNUNET_DHT_get_stop (rh->get_handle); GNUNET_SCHEDULER_cancel(rh->dht_timeout_task); rh->get_handle = NULL; name = (char*)&nrb[1]; num_records = ntohl(nrb->rd_count); { struct GNUNET_NAMESTORE_RecordData rd[num_records]; rd_data += strlen(name) + 1 + sizeof(struct GNSNameRecordBlock); rd_size = size - strlen(name) - 1 - sizeof(struct GNSNameRecordBlock); if (GNUNET_SYSERR == GNUNET_NAMESTORE_records_deserialize (rd_size, rd_data, num_records, rd)) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Error deserializing data!\n"); return; } for (i=0; iname); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got type: %d (wanted %d)\n", rd[i].record_type, rh->query->type); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got data length: %d\n", rd[i].data_size); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got flag %d\n", rd[i].flags); if ((strcmp(name, rh->name) == 0) && (rd[i].record_type == rh->query->type)) { rh->answered++; } } GNUNET_CRYPTO_hash(name, strlen(name), &name_hash); GNUNET_CRYPTO_hash_xor(key, &name_hash, &zone); /** * FIXME check pubkey against existing key in namestore? * https://gnunet.org/bugs/view.php?id=2179 */ /* Save to namestore */ GNUNET_NAMESTORE_record_put (namestore_handle, &nrb->public_key, name, exp, num_records, rd, &nrb->signature, &on_namestore_record_put_result, //cont NULL); //cls if (rh->answered) reply_to_dns(rh, num_records, rd); else reply_to_dns(rh, 0, NULL); } } /** * Start DHT lookup for a (name -> query->record_type) record in * query->authority's zone * * @param rh the pending gns query context * @param name the name to query record */ static void resolve_name_dht(struct GNUNET_GNS_ResolverHandle *rh, const char* name) { uint32_t xquery; GNUNET_HashCode name_hash; GNUNET_HashCode lookup_key; struct GNUNET_CRYPTO_HashAsciiEncoded lookup_key_string; GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "A\n"); GNUNET_CRYPTO_hash(name, strlen(name), &name_hash); GNUNET_CRYPTO_hash_xor(&name_hash, &rh->authority, &lookup_key); GNUNET_CRYPTO_hash_to_enc (&lookup_key, &lookup_key_string); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "starting dht lookup for %s with key: %s\n", name, (char*)&lookup_key_string); rh->dht_timeout_task = GNUNET_SCHEDULER_add_delayed(DHT_LOOKUP_TIMEOUT, &dht_lookup_timeout, rh); xquery = htonl(rh->query->type); //FIXME how long to wait for results? rh->get_handle = GNUNET_DHT_get_start(dht_handle, DHT_OPERATION_TIMEOUT, GNUNET_BLOCK_TYPE_GNS_NAMERECORD, &lookup_key, DHT_GNS_REPLICATION_LEVEL, GNUNET_DHT_RO_NONE, &xquery, sizeof(xquery), &process_name_dht_result, rh); } //Prototype static void resolve_name(struct GNUNET_GNS_ResolverHandle *rh); /** * This is a callback function that should give us only PKEY * records. Used to query the namestore for the authority (PKEY) * for 'name' * * @param cls the pending query * @param key the key of the zone we did the lookup * @param expiration expiration date of the record data set in the namestore * @param name the name for which we need an authority * @param rd_count the number of records with 'name' * @param rd the record data * @param signature the signature of the authority for the record data */ static void process_authority_lookup(void* cls, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *key, struct GNUNET_TIME_Absolute expiration, const char *name, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, const struct GNUNET_CRYPTO_RsaSignature *signature) { struct GNUNET_GNS_ResolverHandle *rh; struct GNUNET_TIME_Relative remaining_time; GNUNET_HashCode zone; GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Got %d records from authority lookup\n", rd_count); rh = (struct GNUNET_GNS_ResolverHandle *)cls; GNUNET_CRYPTO_hash(key, sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), &zone); remaining_time = GNUNET_TIME_absolute_get_remaining (expiration); /** * No authority found in namestore. */ if (rd_count == 0) { /** * We did not find an authority in the namestore * _IF_ the current authoritative zone is us we cannot resolve * _ELSE_ we can still check the _expired_ dht */ if ((0 != GNUNET_CRYPTO_hash_cmp(&rh->authority, &zone_hash)) && (remaining_time.rel_value == 0)) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Authority %s unknown in namestore, trying dht\n", rh->authority_name); resolve_authority_dht(rh); return; } GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Authority %s unknown\n", rh->authority_name); reply_to_dns(rh, 0, NULL); return; } //Note only 1 pkey should have been returned.. anything else would be strange /** * We found an authority that may be able to help us * move on with query */ int i; for (i=0; iauthority); resolve_name(rh); return; } /** * no answers found */ GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Authority lookup successful but no PKEY... never get here\n"); reply_to_dns(rh, 0, NULL); } /** * Reply to client with the result from our lookup. * * @param rh the request handle of the lookup * @param rd_count the number of records to return * @param rd the record data */ static void reply_to_dns(struct GNUNET_GNS_ResolverHandle *rh, uint32_t rd_count, const struct GNUNET_NAMESTORE_RecordData *rd) { int i; size_t len; int ret; char *buf; struct GNUNET_DNSPARSER_Packet *packet = rh->packet; struct GNUNET_DNSPARSER_Record answer_records[rh->answered]; struct GNUNET_DNSPARSER_Record additional_records[rd_count-(rh->answered)]; packet->answers = answer_records; packet->additional_records = additional_records; /** * Put records in the DNS packet and modify it * to a response */ len = sizeof(struct GNUNET_DNSPARSER_Record*); for (i=0; i < rd_count; i++) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Adding type %d to DNS response\n", rd[i].record_type); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Name: %s\n", rh->name); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "QName: %s\n", rh->query->name); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Record %d/%d\n", i+1, rd_count); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Record len %d\n", rd[i].data_size); if (rd[i].record_type == rh->query->type) { answer_records[i].name = rh->query->name; answer_records[i].type = rd[i].record_type; answer_records[i].data.raw.data_len = rd[i].data_size; answer_records[i].data.raw.data = (char*)rd[i].data; answer_records[i].expiration_time = rd[i].expiration; answer_records[i].class = GNUNET_DNSPARSER_CLASS_INTERNET;//hmmn } else { additional_records[i].name = rh->query->name; additional_records[i].type = rd[i].record_type; additional_records[i].data.raw.data_len = rd[i].data_size; additional_records[i].data.raw.data = (char*)rd[i].data; additional_records[i].expiration_time = rd[i].expiration; additional_records[i].class = GNUNET_DNSPARSER_CLASS_INTERNET;//hmmn } } packet->num_answers = rh->answered; packet->num_additional_records = rd_count-(rh->answered); if (0 == GNUNET_CRYPTO_hash_cmp(&rh->authority, &zone_hash)) packet->flags.authoritative_answer = 1; else packet->flags.authoritative_answer = 0; if (rd == NULL) packet->flags.return_code = GNUNET_DNSPARSER_RETURN_CODE_NAME_ERROR; else packet->flags.return_code = GNUNET_DNSPARSER_RETURN_CODE_NO_ERROR; packet->flags.query_or_response = 1; /** * Reply to DNS */ GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Building DNS response\n"); ret = GNUNET_DNSPARSER_pack (packet, 1024, /* FIXME magic from dns redirector */ &buf, &len); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Built DNS response! (ret=%d,len=%d)\n", ret, len); if (ret == GNUNET_OK) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answering DNS request\n"); GNUNET_DNS_request_answer(rh->request_handle, len, buf); //GNUNET_free(answer); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answered DNS request\n"); } else { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Error building DNS response! (ret=%d)", ret); } GNUNET_free(rh->name); GNUNET_free(rh); } /** * Namestore calls this function if we have record for this name. * (or with rd_count=0 to indicate no matches) * * @param cls the pending query * @param key the key of the zone we did the lookup * @param expiration expiration date of the namestore entry * @param name the name for which we need an authority * @param rd_count the number of records with 'name' * @param rd the record data * @param signature the signature of the authority for the record data */ static void process_authoritative_result(void* cls, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *key, struct GNUNET_TIME_Absolute expiration, const char *name, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, const struct GNUNET_CRYPTO_RsaSignature *signature) { struct GNUNET_GNS_ResolverHandle *rh; struct GNUNET_TIME_Relative remaining_time; GNUNET_HashCode zone; rh = (struct GNUNET_GNS_ResolverHandle *) cls; GNUNET_CRYPTO_hash(key, sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), &zone); remaining_time = GNUNET_TIME_absolute_get_remaining (expiration); if (rd_count == 0) { /** * Lookup terminated and no results * -> DHT Phase unless data is recent */ GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Namestore lookup for %s terminated without results\n", name); /** * if this is not our zone we cannot rely on the namestore to be * complete. -> Query DHT */ if (GNUNET_CRYPTO_hash_cmp(&zone, &zone_hash)) { if (remaining_time.rel_value == 0) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "trying dht...\n"); resolve_name_dht(rh, rh->name); return; } else { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Record is still recent. No DHT lookup\n"); } } /** * Our zone and no result? Cannot resolve TT */ GNUNET_assert(rh->answered == 0); reply_to_dns(rh, 0, NULL); return; } else { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Processing additional result %s from namestore\n", name); int i; for (i=0; iquery->name) == 0) && (rd[i].record_type != rh->query->type)) continue; if ((GNUNET_TIME_absolute_get_remaining (rd[i].expiration)).rel_value == 0) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "This record is expired. Skipping\n"); continue; } rh->answered++; } /** * no answers found * consult dht if expired */ if ((remaining_time.rel_value == 0) && (rh->answered == 0)) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "This dht entry is old. Refreshing.\n"); resolve_name_dht(rh, name); return; } GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Found %d answer(s) to query!\n", rh->answered); reply_to_dns(rh, rd_count, rd); } } /** * Determine if this name is canonical. * i.e. * a.b.gnunet = not canonical * a = canonical * * @param name the name to test * @return 1 if canonical */ static int is_canonical(char* name) { uint32_t len = strlen(name); int i; for (i=0; i 0; len--) { if (*(name+len) == '.') break; } if (len == 0) return NULL; name[len] = '\0'; return (name+len+1); } /** * The first phase of resolution. * First check if the name is canonical. * If it is then try to resolve directly. * If not then we first have to resolve the authoritative entities. * * @param rh the pending lookup */ static void resolve_name(struct GNUNET_GNS_ResolverHandle *rh) { if (is_canonical(rh->name)) { /* We only need to check the current zone's ns */ GNUNET_NAMESTORE_lookup_record(namestore_handle, &rh->authority, rh->name, rh->query->type, &process_authoritative_result, rh); } else { /* We have to resolve the authoritative entity first */ rh->authority_name = pop_tld(rh->name); GNUNET_NAMESTORE_lookup_record(namestore_handle, &rh->authority, rh->authority_name, GNUNET_GNS_RECORD_PKEY, &process_authority_lookup, rh); } } /** * Entry point for name resolution * Setup a new query and try to resolve * * @param request the request handle of the DNS request from a client * @param p the DNS query packet we received * @param q the DNS query we received parsed from p */ static void start_resolution(struct GNUNET_DNS_RequestHandle *request, struct GNUNET_DNSPARSER_Packet *p, struct GNUNET_DNSPARSER_Query *q) { struct GNUNET_GNS_ResolverHandle *rh; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting resolution for %s (type=%d)!\n", q->name, q->type); rh = GNUNET_malloc(sizeof (struct GNUNET_GNS_ResolverHandle)); rh->packet = p; rh->query = q; rh->authority = zone_hash; rh->name = GNUNET_malloc(strlen(q->name) - strlen(gnunet_tld) + 1); memset(rh->name, 0, strlen(q->name)-strlen(gnunet_tld) + 1); memcpy(rh->name, q->name, strlen(q->name)-strlen(gnunet_tld)); rh->request_handle = request; /* Start resolution in our zone */ resolve_name(rh); } /** * The DNS request handler * Called for every incoming DNS request. * * @param cls closure * @param rh request handle to user for reply * @param request_length number of bytes in request * @param request udp payload of the DNS request */ static void handle_dns_request(void *cls, struct GNUNET_DNS_RequestHandle *rh, size_t request_length, const char *request) { struct GNUNET_DNSPARSER_Packet *p; char *tldoffset; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacked a DNS request...processing\n"); p = GNUNET_DNSPARSER_parse (request, request_length); if (NULL == p) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Received malformed DNS packet, leaving it untouched\n"); GNUNET_DNS_request_forward (rh); return; } /** * Check tld and decide if we or * legacy dns is responsible * * FIXME now in theory there could be more than 1 query in the request * but if this is case we get into trouble: * either we query the GNS or the DNS. We cannot do both! * So I suggest to either only allow a single query per request or * only allow GNS or DNS requests. * The way it is implemented here now is buggy and will lead to erratic * behaviour (if multiple queries are present). */ if (p->num_queries == 0) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "No Queries in DNS packet... forwarding\n"); GNUNET_DNS_request_forward (rh); } if (p->num_queries > 1) { /* Note: We could also look for .gnunet */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, ">1 queriy in DNS packet... odd. We only process #1\n"); } /** * Check for .gnunet */ tldoffset = p->queries[0].name + strlen(p->queries[0].name); while ((*tldoffset) != '.') tldoffset--; if (0 == strcmp(tldoffset, gnunet_tld)) { start_resolution(rh, p, p->queries); } else { /** * This request does not concern us. Forward to real DNS. */ GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Request for %s is forwarded to DNS\n", p->queries[0].name); GNUNET_DNS_request_forward (rh); } } /** * Method called periodicattluy that triggers * iteration over root zone * * @param cls closure * @param tc task context */ static void update_zone_dht_next(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { GNUNET_NAMESTORE_zone_iterator_next(namestore_iter); } /** * Continuation for DHT put * * @param cls closure * @param tc task context */ static void record_dht_put(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "put request transmitted\n"); } /* prototype */ static void update_zone_dht_start(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); /** * Function used to put all records successively into the DHT. * * @param cls the closure (NULL) * @param key the public key of the authority (ours) * @param expiration lifetime of the namestore entry * @param name the name of the records * @param rd_count the number of records in data * @param rd the record data * @param signature the signature for the record data */ static void put_gns_record(void *cls, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *key, struct GNUNET_TIME_Absolute expiration, const char *name, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, const struct GNUNET_CRYPTO_RsaSignature *signature) { struct GNSNameRecordBlock *nrb; GNUNET_HashCode name_hash; GNUNET_HashCode xor_hash; struct GNUNET_CRYPTO_HashAsciiEncoded xor_hash_string; uint32_t rd_payload_length; char* nrb_data = NULL; /* we're done */ if (NULL == name) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Zone iteration finished\n"); GNUNET_NAMESTORE_zone_iteration_stop (namestore_iter); zone_update_taskid = GNUNET_SCHEDULER_add_now (&update_zone_dht_start, NULL); return; } GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Putting records for %s into the DHT\n", name); rd_payload_length = GNUNET_NAMESTORE_records_get_size (rd_count, rd); nrb = GNUNET_malloc(rd_payload_length + strlen(name) + 1 + sizeof(struct GNSNameRecordBlock)); if (signature != NULL) nrb->signature = *signature; nrb->public_key = *key; nrb->rd_count = htonl(rd_count); memset(&nrb[1], 0, strlen(name) + 1); memcpy(&nrb[1], name, strlen(name)); nrb_data = (char*)&nrb[1]; nrb_data += strlen(name) + 1; rd_payload_length += sizeof(struct GNSNameRecordBlock) + strlen(name) + 1; if (-1 == GNUNET_NAMESTORE_records_serialize (rd_count, rd, rd_payload_length, nrb_data)) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Record serialization failed!\n"); return; //FIXME what to do } /* * calculate DHT key: H(name) xor H(pubkey) */ GNUNET_CRYPTO_hash(name, strlen(name), &name_hash); GNUNET_CRYPTO_hash_xor(&zone_hash, &name_hash, &xor_hash); GNUNET_CRYPTO_hash_to_enc (&xor_hash, &xor_hash_string); GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "putting records for %s under key: %s with size %d\n", name, (char*)&xor_hash_string, rd_payload_length); GNUNET_DHT_put (dht_handle, &xor_hash, DHT_GNS_REPLICATION_LEVEL, GNUNET_DHT_RO_NONE, GNUNET_BLOCK_TYPE_GNS_NAMERECORD, rd_payload_length, (char*)nrb, expiration, DHT_OPERATION_TIMEOUT, &record_dht_put, NULL); //cls for cont num_public_records++; /** * Reschedule periodic put */ zone_update_taskid = GNUNET_SCHEDULER_add_delayed (dht_update_interval, &update_zone_dht_next, NULL); } /** * Periodically iterate over our zone and store everything in dht * * @param cls NULL * @param tc task context */ static void update_zone_dht_start(void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Starting DHT zone update!\n"); if (0 == num_public_records) { dht_update_interval = GNUNET_TIME_relative_multiply( GNUNET_TIME_UNIT_SECONDS, 1); } else { dht_update_interval = GNUNET_TIME_relative_multiply( GNUNET_TIME_UNIT_SECONDS, (3600/num_public_records)); } num_public_records = 0; //start counting again namestore_iter = GNUNET_NAMESTORE_zone_iteration_start (namestore_handle, &zone_hash, GNUNET_NAMESTORE_RF_AUTHORITY, GNUNET_NAMESTORE_RF_PRIVATE, &put_gns_record, NULL); } /** * Process GNS requests. * * @param cls closure * @param server the initialized server * @param c configuration to use */ static void run (void *cls, struct GNUNET_SERVER_Handle *server, const struct GNUNET_CONFIGURATION_Handle *c) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Initializing GNS\n"); char* keyfile; struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pkey; if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (c, "gns", "ZONEKEY", &keyfile)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No private key for root zone specified%s!\n", keyfile); GNUNET_SCHEDULER_shutdown(0); return; } zone_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile); GNUNET_CRYPTO_rsa_key_get_public (zone_key, &pkey); GNUNET_CRYPTO_hash(&pkey, sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), &zone_hash); nc = GNUNET_SERVER_notification_context_create (server, 1); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task, NULL); if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno (c, "gns", "HIJACK_DNS")) { GNUNET_log(GNUNET_ERROR_TYPE_INFO, "DNS hijacking enabled... connecting to service.\n"); /** * Do gnunet dns init here */ dns_handle = GNUNET_DNS_connect(c, GNUNET_DNS_FLAG_PRE_RESOLUTION, &handle_dns_request, /* rh */ NULL); /* Closure */ if (NULL == dns_handle) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Failed to connect to the dnsservice!\n"); } } /** * handle to our local namestore */ namestore_handle = GNUNET_NAMESTORE_connect(c); if (NULL == namestore_handle) { //FIXME do error handling; GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Failed to connect to the namestore!\n"); GNUNET_SCHEDULER_shutdown(0); return; } /** * handle to the dht */ dht_handle = GNUNET_DHT_connect(c, 1); //FIXME get ht_len from cfg if (NULL == dht_handle) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "Could not connect to DHT!\n"); } //put_some_records(); //FIXME for testing /** * Schedule periodic put * for our records * We have roughly an hour for all records; */ dht_update_interval = GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 1); //zone_update_taskid = GNUNET_SCHEDULER_add_now (&update_zone_dht_start, NULL); } /** * The main function for the GNS service. * * @param argc number of arguments from the command line * @param argv command line arguments * @return 0 ok, 1 on error */ int main (int argc, char *const *argv) { int ret; ret = (GNUNET_OK == GNUNET_SERVICE_run (argc, argv, "gns", GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1; return ret; } /* end of gnunet-service-gns.c */