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3 (C) 2011-2013 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file gns/gnunet-service-gns_resolver.c
23 * @brief GNU Name System resolver logic
24 * @author Martin Schanzenbach
25 * @author Christian Grothoff
28 * - GNS: handle special SRV names --- no delegation, direct lookup;
29 * can likely be done in 'resolver_lookup_get_next_label'. (#3003)
30 * - revocation checks (use REVOCATION service!), (#3004)
31 * - DNAME support (#3005)
34 #include "gnunet_util_lib.h"
35 #include "gnunet_dnsstub_lib.h"
36 #include "gnunet_dht_service.h"
37 #include "gnunet_gnsrecord_lib.h"
38 #include "gnunet_namecache_service.h"
39 #include "gnunet_namestore_service.h"
40 #include "gnunet_dns_service.h"
41 #include "gnunet_resolver_service.h"
42 #include "gnunet_revocation_service.h"
43 #include "gnunet_dnsparser_lib.h"
44 #include "gnunet_gns_service.h"
46 #include "gnunet-service-gns_resolver.h"
47 #include "gnunet-service-gns_shorten.h"
48 #include "gnunet_vpn_service.h"
52 * Default DHT timeout for lookups.
54 #define DHT_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)
57 * Default timeout for DNS lookups.
59 #define DNS_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
62 * Default timeout for VPN redirections.
64 #define VPN_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30)
67 * DHT replication level
69 #define DHT_GNS_REPLICATION_LEVEL 5
72 * How deep do we allow recursions to go before we abort?
74 #define MAX_RECURSION 256
78 * DLL to hold the authority chain we had to pass in the resolution
86 struct AuthorityChain *prev;
91 struct AuthorityChain *next;
94 * Resolver handle this entry in the chain belongs to.
96 struct GNS_ResolverHandle *rh;
99 * label/name corresponding to the authority
104 * #GNUNET_YES if the authority was a GNS authority,
105 * #GNUNET_NO if the authority was a DNS authority.
110 * Information about the resolver authority for this label.
116 * The zone of the GNS authority
118 struct GNUNET_CRYPTO_EcdsaPublicKey gns_authority;
123 * Domain of the DNS resolver that is the authority.
124 * (appended to construct the DNS name to resolve;
125 * this is NOT the DNS name of the DNS server!).
127 char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
130 * IP address of the DNS resolver that is authoritative.
131 * (this implementation currently only supports one
134 struct sockaddr_storage dns_ip;
144 * A result we got from DNS.
152 struct DnsResult *next;
157 struct DnsResult *prev;
160 * Binary value stored in the DNS record (appended to this struct)
165 * Expiration time for the DNS record, 0 if we didn't
166 * get anything useful (i.e. 'gethostbyname' was used).
168 uint64_t expiration_time;
171 * Number of bytes in @e data.
176 * Type of the GNS/DNS record.
178 uint32_t record_type;
184 * Closure for #vpn_allocation_cb.
190 * Which resolution process are we processing.
192 struct GNS_ResolverHandle *rh;
195 * Handle to the VPN request that we were performing.
197 struct GNUNET_VPN_RedirectionRequest *vpn_request;
200 * Number of records serialized in @e rd_data.
202 unsigned int rd_count;
205 * Serialized records.
210 * Number of bytes in @e rd_data.
217 * Information we keep during the resolution of an
218 * IP address for a DNS server while handling a
221 struct Gns2DnsContext
225 * DNS domain in which the resolution will continue
226 * (first part of the GNS2DNS record).
231 * Handle for the resolution of the IP part of the
232 * GNS2DNS record. Will return to us the addresses
233 * of the DNS resolver to use.
235 struct GNS_ResolverHandle *rh;
241 * Handle to a currenty pending resolution. On result (positive or
242 * negative) the #GNS_ResultProcessor is called.
244 struct GNS_ResolverHandle
250 struct GNS_ResolverHandle *next;
255 struct GNS_ResolverHandle *prev;
258 * The top-level GNS authoritative zone to query
260 struct GNUNET_CRYPTO_EcdsaPublicKey authority_zone;
263 * called when resolution phase finishes
265 GNS_ResultProcessor proc;
268 * closure passed to @e proc
273 * Handle used during GNS2DNS resolution for looking up the
274 * IP address of the DNS server.
276 struct Gns2DnsContext *g2dc;
279 * Handle for DHT lookups. should be NULL if no lookups are in progress
281 struct GNUNET_DHT_GetHandle *get_handle;
284 * Handle to a VPN request, NULL if none is active.
286 struct VpnContext *vpn_ctx;
289 * Socket for a DNS request, NULL if none is active.
291 struct GNUNET_DNSSTUB_RequestSocket *dns_request;
294 * Handle for standard DNS resolution, NULL if none is active.
296 struct GNUNET_RESOLVER_RequestHandle *std_resolve;
299 * Pending Namecache lookup task
301 struct GNUNET_NAMECACHE_QueueEntry *namecache_qe;
304 * Pending revocation check.
306 struct GNUNET_REVOCATION_Query *rev_check;
309 * Heap node associated with this lookup. Used to limit number of
310 * concurrent requests.
312 struct GNUNET_CONTAINER_HeapNode *dht_heap_node;
315 * DLL to store the authority chain
317 struct AuthorityChain *ac_head;
320 * DLL to store the authority chain
322 struct AuthorityChain *ac_tail;
325 * Private key of the shorten zone, NULL to not shorten.
327 struct GNUNET_CRYPTO_EcdsaPrivateKey *shorten_key;
330 * ID of a task associated with the resolution process.
332 GNUNET_SCHEDULER_TaskIdentifier task_id;
335 * The name to resolve
340 * DLL of results we got from DNS.
342 struct DnsResult *dns_result_head;
345 * DLL of results we got from DNS.
347 struct DnsResult *dns_result_tail;
350 * Current offset in 'name' where we are resolving.
352 size_t name_resolution_pos;
360 * Desired type for the resolution.
365 * We increment the loop limiter for each step in a recursive
366 * resolution. If it passes our threshold (i.e. due to
367 * self-recursion in the resolution, i.e CNAME fun), we stop.
369 unsigned int loop_limiter;
375 * Active namestore caching operations.
381 * Organized in a DLL.
383 struct CacheOps *next;
386 * Organized in a DLL.
388 struct CacheOps *prev;
391 * Pending Namestore caching task.
393 struct GNUNET_NAMECACHE_QueueEntry *namecache_qe_cache;
399 * Our handle to the namecache service
401 static struct GNUNET_NAMECACHE_Handle *namecache_handle;
404 * Our handle to the vpn service
406 static struct GNUNET_VPN_Handle *vpn_handle;
409 * Resolver handle to the dht
411 static struct GNUNET_DHT_Handle *dht_handle;
414 * Handle to perform DNS lookups.
416 static struct GNUNET_DNSSTUB_Context *dns_handle;
419 * Heap for limiting parallel DHT lookups
421 static struct GNUNET_CONTAINER_Heap *dht_lookup_heap;
424 * Maximum amount of parallel queries to the DHT
426 static unsigned long long max_allowed_background_queries;
429 * Head of resolver lookup list
431 static struct GNS_ResolverHandle *rlh_head;
434 * Tail of resolver lookup list
436 static struct GNS_ResolverHandle *rlh_tail;
439 * Organized in a DLL.
441 static struct CacheOps *co_head;
444 * Organized in a DLL.
446 static struct CacheOps *co_tail;
450 * Global configuration.
452 static const struct GNUNET_CONFIGURATION_Handle *cfg;
456 * Check if name is in srv format (_x._y.xxx)
459 * @return #GNUNET_YES if true
462 is_srv (const char *name)
469 if (NULL == strstr (name, "._"))
472 ndup = GNUNET_strdup (name);
474 if (NULL == strtok (NULL, "."))
476 if (NULL == strtok (NULL, "."))
478 if (NULL != strtok (NULL, "."))
487 * Determine if this name is canonical (is a legal name in a zone, without delegation);
488 * note that we do not test that the name does not contain illegal characters, we only
489 * test for delegation. Note that service records (i.e. _foo._srv) are canonical names
490 * even though they consist of multiple labels.
493 * a.b.gnu = not canonical
495 * _foo._srv = canonical
496 * _f.bar = not canonical
498 * @param name the name to test
499 * @return #GNUNET_YES if canonical
502 is_canonical (const char *name)
507 if (NULL == strchr (name, '.'))
512 while (NULL != (dot = strchr (pos, '.')))
520 /* ************************** Resolution **************************** */
523 * Expands a name ending in .+ with the zone of origin.
525 * @param rh resolution context
526 * @param name name to modify (to be free'd or returned)
527 * @return updated name
530 translate_dot_plus (struct GNS_ResolverHandle *rh,
534 size_t s_len = strlen (name);
536 if (0 != strcmp (&name[s_len - 2],
538 return name; /* did not end in ".+" */
539 GNUNET_assert (GNUNET_YES == rh->ac_tail->gns_authority);
540 GNUNET_asprintf (&ret,
544 GNUNET_GNSRECORD_pkey_to_zkey (&rh->ac_tail->authority_info.gns_authority));
551 * Task scheduled to asynchronously fail a resolution.
553 * @param cls the 'struct GNS_ResolverHandle' of the resolution to fail
554 * @param tc task context
557 fail_resolution (void *cls,
558 const struct GNUNET_SCHEDULER_TaskContext *tc)
560 struct GNS_ResolverHandle *rh = cls;
562 rh->task_id = GNUNET_SCHEDULER_NO_TASK;
563 rh->proc (rh->proc_cls, 0, NULL);
564 GNS_resolver_lookup_cancel (rh);
568 #if (defined WINDOWS) || (defined DARWIN)
569 /* Don't have this on W32, here's a naive implementation
570 * Was somehow removed on OS X ... */
572 memrchr (const void *s,
576 const unsigned char *ucs = s;
579 for (i = n - 1; i >= 0; i--)
580 if (c == (int) ucs[i])
581 return (void *) &ucs[i];
588 * Get the next, rightmost label from the name that we are trying to resolve,
589 * and update the resolution position accordingly.
591 * @param rh handle to the resolution operation to get the next label from
592 * @return NULL if there are no more labels
595 resolver_lookup_get_next_label (struct GNS_ResolverHandle *rh)
601 if (0 == rh->name_resolution_pos)
603 dot = memrchr (rh->name, (int) '.', rh->name_resolution_pos);
606 /* done, this was the last one */
607 len = rh->name_resolution_pos;
609 rh->name_resolution_pos = 0;
613 /* advance by one label */
614 len = rh->name_resolution_pos - (dot - rh->name) - 1;
616 rh->name_resolution_pos = dot - rh->name;
618 return GNUNET_strndup (rp, len);
623 * Gives the cummulative result obtained to the callback and clean up the request.
625 * @param rh resolution process that has culminated in a result
628 transmit_lookup_dns_result (struct GNS_ResolverHandle *rh)
630 struct DnsResult *pos;
635 for (pos = rh->dns_result_head; NULL != pos; pos = pos->next)
638 struct GNUNET_GNSRECORD_Data rd[n];
641 for (pos = rh->dns_result_head; NULL != pos; pos = pos->next)
643 rd[i].data = pos->data;
644 rd[i].data_size = pos->data_size;
645 rd[i].record_type = pos->record_type;
646 if (0 == pos->expiration_time)
648 rd[i].flags = GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION;
649 rd[i].expiration_time = 0;
653 rd[i].flags = GNUNET_GNSRECORD_RF_NONE;
654 rd[i].expiration_time = pos->expiration_time;
658 GNUNET_assert (i == n);
659 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
660 "Transmitting standard DNS result with %u records\n",
662 rh->proc (rh->proc_cls,
666 GNS_resolver_lookup_cancel (rh);
671 * Add a result from DNS to the records to be returned to the application.
673 * @param rh resolution request to extend with a result
674 * @param expiration_time expiration time for the answer
675 * @param record_type DNS record type of the answer
676 * @param data_size number of bytes in @a data
677 * @param data binary data to return in DNS record
680 add_dns_result (struct GNS_ResolverHandle *rh,
681 uint64_t expiration_time,
682 uint32_t record_type,
686 struct DnsResult *res;
688 res = GNUNET_malloc (sizeof (struct DnsResult) + data_size);
689 res->expiration_time = expiration_time;
690 res->data_size = data_size;
691 res->record_type = record_type;
693 memcpy (&res[1], data, data_size);
694 GNUNET_CONTAINER_DLL_insert (rh->dns_result_head,
701 * We had to do a DNS lookup. Convert the result (if any) and return
704 * @param cls closure with the `struct GNS_ResolverHandle`
705 * @param addr one of the addresses of the host, NULL for the last address
706 * @param addrlen length of the address
709 handle_dns_result (void *cls,
710 const struct sockaddr *addr,
713 struct GNS_ResolverHandle *rh = cls;
714 const struct sockaddr_in *sa4;
715 const struct sockaddr_in6 *sa6;
717 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
718 "Received %u bytes of DNS IP data\n",
722 rh->std_resolve = NULL;
723 transmit_lookup_dns_result (rh);
726 switch (addr->sa_family)
729 sa4 = (const struct sockaddr_in *) addr;
731 0 /* expiration time is unknown */,
732 GNUNET_DNSPARSER_TYPE_A,
733 sizeof (struct in_addr),
737 sa6 = (const struct sockaddr_in6 *) addr;
739 0 /* expiration time is unknown */,
740 GNUNET_DNSPARSER_TYPE_AAAA,
741 sizeof (struct in6_addr),
752 * Task scheduled to continue with the resolution process.
754 * @param cls the 'struct GNS_ResolverHandle' of the resolution
755 * @param tc task context
758 recursive_resolution (void *cls,
759 const struct GNUNET_SCHEDULER_TaskContext *tc);
763 * Begin the resolution process from 'name', starting with
764 * the identification of the zone specified by 'name'.
766 * @param rh resolution to perform
769 start_resolver_lookup (struct GNS_ResolverHandle *rh);
773 * Function called with the result of a DNS resolution.
775 * @param cls the request handle of the resolution that
776 * we were attempting to make
777 * @param rs socket that received the response
778 * @param dns dns response, never NULL
779 * @param dns_len number of bytes in @a dns
782 dns_result_parser (void *cls,
783 struct GNUNET_DNSSTUB_RequestSocket *rs,
784 const struct GNUNET_TUN_DnsHeader *dns,
787 struct GNS_ResolverHandle *rh = cls;
788 struct GNUNET_DNSPARSER_Packet *p;
789 const struct GNUNET_DNSPARSER_Record *rec;
790 unsigned int rd_count;
793 rh->dns_request = NULL;
794 GNUNET_SCHEDULER_cancel (rh->task_id);
795 rh->task_id = GNUNET_SCHEDULER_NO_TASK;
796 p = GNUNET_DNSPARSER_parse ((const char *) dns,
800 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
801 _("Failed to parse DNS response\n"));
802 rh->proc (rh->proc_cls, 0, NULL);
803 GNS_resolver_lookup_cancel (rh);
806 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
807 "Received DNS response for `%s' with %u answers\n",
809 (unsigned int) p->num_answers);
810 if ( (p->num_answers > 0) &&
811 (GNUNET_DNSPARSER_TYPE_CNAME == p->answers[0].type) &&
812 (GNUNET_DNSPARSER_TYPE_CNAME != rh->record_type) )
814 GNUNET_free (rh->name);
815 rh->name = GNUNET_strdup (p->answers[0].data.hostname);
816 start_resolver_lookup (rh);
817 GNUNET_DNSPARSER_free_packet (p);
820 /* FIXME: add DNAME support */
822 /* convert from (parsed) DNS to (binary) GNS format! */
823 rd_count = p->num_answers + p->num_authority_records + p->num_additional_records;
825 struct GNUNET_GNSRECORD_Data rd[rd_count];
827 char buf[UINT16_MAX];
833 memset (rd, 0, sizeof (rd));
834 for (i=0;i<rd_count;i++)
836 if (i < p->num_answers)
837 rec = &p->answers[i];
838 else if (i < p->num_answers + p->num_authority_records)
839 rec = &p->authority_records[i - p->num_answers];
841 rec = &p->authority_records[i - p->num_answers - p->num_authority_records];
842 /* As we copied the full DNS name to 'rh->ac_tail->label', this
843 should be the correct check to see if this record is actually
844 a record for our label... */
845 if (0 != strcmp (rec->name,
848 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
849 "Dropping record `%s', does not match desired name `%s'\n",
855 rd[i - skip].record_type = rec->type;
856 rd[i - skip].expiration_time = rec->expiration_time.abs_value_us;
859 case GNUNET_DNSPARSER_TYPE_A:
860 if (rec->data.raw.data_len != sizeof (struct in_addr))
866 rd[i - skip].data_size = rec->data.raw.data_len;
867 rd[i - skip].data = rec->data.raw.data;
869 case GNUNET_DNSPARSER_TYPE_AAAA:
870 if (rec->data.raw.data_len != sizeof (struct in6_addr))
876 rd[i - skip].data_size = rec->data.raw.data_len;
877 rd[i - skip].data = rec->data.raw.data;
879 case GNUNET_DNSPARSER_TYPE_CNAME:
880 case GNUNET_DNSPARSER_TYPE_PTR:
881 case GNUNET_DNSPARSER_TYPE_NS:
884 GNUNET_DNSPARSER_builder_add_name (buf,
893 rd[i - skip].data_size = buf_off - buf_start;
894 rd[i - skip].data = &buf[buf_start];
896 case GNUNET_DNSPARSER_TYPE_SOA:
899 GNUNET_DNSPARSER_builder_add_soa (buf,
908 rd[i - skip].data_size = buf_off - buf_start;
909 rd[i - skip].data = &buf[buf_start];
911 case GNUNET_DNSPARSER_TYPE_MX:
914 GNUNET_DNSPARSER_builder_add_mx (buf,
923 rd[i - skip].data_size = buf_off - buf_start;
924 rd[i - skip].data = &buf[buf_start];
926 case GNUNET_DNSPARSER_TYPE_SRV:
929 GNUNET_DNSPARSER_builder_add_srv (buf,
938 rd[i - skip].data_size = buf_off - buf_start;
939 rd[i - skip].data = &buf[buf_start];
942 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
943 _("Skipping record of unsupported type %d\n"),
949 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
950 "Returning DNS response for `%s' with %u answers\n",
952 (unsigned int) p->num_answers);
953 rh->proc (rh->proc_cls, rd_count - skip, rd);
954 GNS_resolver_lookup_cancel (rh);
956 GNUNET_DNSPARSER_free_packet (p);
961 * Perform recursive DNS resolution. Asks the given DNS resolver to
962 * resolve "rh->dns_name", possibly recursively proceeding following
963 * NS delegations, CNAMES, etc., until 'rh->loop_limiter' bounds us or
964 * we find the answer.
966 * @param rh resolution information
969 recursive_dns_resolution (struct GNS_ResolverHandle *rh)
971 struct AuthorityChain *ac;
973 struct GNUNET_DNSPARSER_Query *query;
974 struct GNUNET_DNSPARSER_Packet *p;
976 size_t dns_request_length;
979 GNUNET_assert (NULL != ac);
980 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
981 "Starting DNS lookup for `%s'\n",
983 GNUNET_assert (GNUNET_NO == ac->gns_authority);
984 switch (((const struct sockaddr *) &ac->authority_info.dns_authority.dns_ip)->sa_family)
987 sa_len = sizeof (struct sockaddr_in);
990 sa_len = sizeof (struct sockaddr_in6);
994 rh->proc (rh->proc_cls, 0, NULL);
995 GNS_resolver_lookup_cancel (rh);
998 query = GNUNET_new (struct GNUNET_DNSPARSER_Query);
999 query->name = GNUNET_strdup (ac->label);
1000 query->type = rh->record_type;
1001 query->dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET;
1002 p = GNUNET_new (struct GNUNET_DNSPARSER_Packet);
1005 p->id = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
1007 p->flags.opcode = GNUNET_TUN_DNS_OPCODE_QUERY;
1008 p->flags.recursion_desired = 1;
1010 GNUNET_DNSPARSER_pack (p, 1024, &dns_request, &dns_request_length))
1013 rh->proc (rh->proc_cls, 0, NULL);
1014 GNS_resolver_lookup_cancel (rh);
1018 rh->dns_request = GNUNET_DNSSTUB_resolve (dns_handle,
1019 (const struct sockaddr *) &ac->authority_info.dns_authority.dns_ip,
1025 rh->task_id = GNUNET_SCHEDULER_add_delayed (DNS_LOOKUP_TIMEOUT,
1029 GNUNET_free (dns_request);
1030 GNUNET_DNSPARSER_free_packet (p);
1035 * We encountered a CNAME record during our resolution.
1036 * Merge it into our chain.
1038 * @param rh resolution we are performing
1039 * @param cname value of the cname record we got for the current
1040 * authority chain tail
1043 handle_gns_cname_result (struct GNS_ResolverHandle *rh,
1048 struct AuthorityChain *ac;
1050 nlen = strlen (cname);
1053 &cname[nlen - 2])) )
1055 /* CNAME resolution continues relative to current domain */
1056 if (0 == rh->name_resolution_pos)
1058 res = GNUNET_strndup (cname, nlen - 2);
1059 rh->name_resolution_pos = nlen - 2;
1063 GNUNET_asprintf (&res,
1065 (int) rh->name_resolution_pos,
1069 rh->name_resolution_pos = strlen (res);
1071 GNUNET_free (rh->name);
1073 ac = GNUNET_new (struct AuthorityChain);
1075 ac->gns_authority = GNUNET_YES;
1076 ac->authority_info.gns_authority = rh->ac_tail->authority_info.gns_authority;
1077 ac->label = resolver_lookup_get_next_label (rh);
1078 /* tigger shortening */
1079 if (NULL != rh->shorten_key)
1080 GNS_shorten_start (rh->ac_tail->label,
1081 &ac->authority_info.gns_authority,
1083 /* add AC to tail */
1084 GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
1087 rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
1091 /* name is absolute, start from the beginning */
1092 GNUNET_free (rh->name);
1093 rh->name = GNUNET_strdup (cname);
1094 start_resolver_lookup (rh);
1099 * Process a records that were decrypted from a block.
1101 * @param cls closure with the 'struct GNS_ResolverHandle'
1102 * @param rd_count number of entries in @a rd array
1103 * @param rd array of records with data to store
1106 handle_gns_resolution_result (void *cls,
1107 unsigned int rd_count,
1108 const struct GNUNET_GNSRECORD_Data *rd);
1112 * Callback invoked from the VPN service once a redirection is
1113 * available. Provides the IP address that can now be used to
1114 * reach the requested destination. Replaces the "VPN" record
1115 * with the respective A/AAAA record and continues processing.
1117 * @param cls closure
1118 * @param af address family, AF_INET or AF_INET6; AF_UNSPEC on error;
1119 * will match 'result_af' from the request
1120 * @param address IP address (struct in_addr or struct in_addr6, depending on 'af')
1121 * that the VPN allocated for the redirection;
1122 * traffic to this IP will now be redirected to the
1123 * specified target peer; NULL on error
1126 vpn_allocation_cb (void *cls,
1128 const void *address)
1130 struct VpnContext *vpn_ctx = cls;
1131 struct GNS_ResolverHandle *rh = vpn_ctx->rh;
1132 struct GNUNET_GNSRECORD_Data rd[vpn_ctx->rd_count];
1135 vpn_ctx->vpn_request = NULL;
1137 GNUNET_assert (GNUNET_OK ==
1138 GNUNET_GNSRECORD_records_deserialize (vpn_ctx->rd_data_size,
1142 for (i=0;i<vpn_ctx->rd_count;i++)
1144 if (GNUNET_GNSRECORD_TYPE_VPN == rd[i].record_type)
1149 rd[i].record_type = GNUNET_DNSPARSER_TYPE_A;
1150 rd[i].data_size = sizeof (struct in_addr);
1151 rd[i].expiration_time = GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT).abs_value_us;
1153 rd[i].data = address;
1156 rd[i].record_type = GNUNET_DNSPARSER_TYPE_AAAA;
1157 rd[i].expiration_time = GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT).abs_value_us;
1159 rd[i].data = address;
1160 rd[i].data_size = sizeof (struct in6_addr);
1168 GNUNET_assert (i < vpn_ctx->rd_count);
1169 handle_gns_resolution_result (rh,
1172 GNUNET_free (vpn_ctx->rd_data);
1173 GNUNET_free (vpn_ctx);
1178 * We've resolved the IP address for the DNS resolver to use
1179 * after encountering a GNS2DNS record.
1181 * TODO: Right now we only foward the request to ONE DNS resolver,
1182 * even if we get multiple IP addresses back; a correct implementation
1183 * should try all DNS resolvers.
1185 * @param cls the `struct GNS_ResolverHandle` where we encountered
1186 * the GNS2DNS record
1187 * @param rd_count number of records in @a rd
1188 * @param rd addresses for the DNS resolver (presumably)
1191 handle_gns2dns_result (void *cls,
1192 unsigned int rd_count,
1193 const struct GNUNET_GNSRECORD_Data *rd)
1195 struct GNS_ResolverHandle *rh = cls;
1196 struct AuthorityChain *ac;
1198 struct sockaddr *sa;
1199 struct sockaddr_in v4;
1200 struct sockaddr_in6 v6;
1203 /* find suitable A/AAAA record */
1204 rh->g2dc->rh = NULL;
1207 for (j=0;j<rd_count;j++)
1209 switch (rd[j].record_type)
1211 case GNUNET_DNSPARSER_TYPE_A:
1212 if (sizeof (struct in_addr) != rd[j].data_size)
1214 GNUNET_break_op (0);
1215 rh->proc (rh->proc_cls, 0, NULL);
1216 GNS_resolver_lookup_cancel (rh);
1219 /* FIXME: might want to check if we support IPv4 here,
1220 and otherwise skip this one and hope we find another */
1221 memset (&v4, 0, sizeof (v4));
1222 sa_len = sizeof (v4);
1223 v4.sin_family = AF_INET;
1224 v4.sin_port = htons (53);
1225 #if HAVE_SOCKADDR_IN_SIN_LEN
1226 v4.sin_len = (u_char) sa_len;
1228 memcpy (&v4.sin_addr,
1230 sizeof (struct in_addr));
1231 sa = (struct sockaddr *) &v4;
1233 case GNUNET_DNSPARSER_TYPE_AAAA:
1234 if (sizeof (struct in6_addr) != rd[j].data_size)
1236 GNUNET_break_op (0);
1237 rh->proc (rh->proc_cls, 0, NULL);
1238 GNS_resolver_lookup_cancel (rh);
1241 /* FIXME: might want to check if we support IPv6 here,
1242 and otherwise skip this one and hope we find another */
1243 memset (&v6, 0, sizeof (v6));
1244 sa_len = sizeof (v6);
1245 v6.sin6_family = AF_INET6;
1246 v6.sin6_port = htons (53);
1247 #if HAVE_SOCKADDR_IN_SIN_LEN
1248 v6.sin6_len = (u_char) sa_len;
1250 memcpy (&v6.sin6_addr,
1252 sizeof (struct in6_addr));
1253 sa = (struct sockaddr *) &v6;
1263 /* we cannot continue; NS without A/AAAA */
1264 rh->proc (rh->proc_cls, 0, NULL);
1265 GNS_resolver_lookup_cancel (rh);
1268 /* expand authority chain */
1269 ac = GNUNET_new (struct AuthorityChain);
1271 strcpy (ac->authority_info.dns_authority.name,
1273 memcpy (&ac->authority_info.dns_authority.dns_ip,
1276 /* for DNS recursion, the label is the full DNS name,
1277 created from the remainder of the GNS name and the
1278 name in the NS record */
1279 GNUNET_asprintf (&ac->label,
1281 (int) rh->name_resolution_pos,
1283 (0 != rh->name_resolution_pos) ? "." : "",
1285 GNUNET_free (rh->g2dc->ns);
1286 GNUNET_free (rh->g2dc);
1288 GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
1291 if (strlen (ac->label) > GNUNET_DNSPARSER_MAX_NAME_LENGTH)
1293 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1294 _("GNS lookup resulted in DNS name that is too long (`%s')\n"),
1296 rh->proc (rh->proc_cls, 0, NULL);
1297 GNS_resolver_lookup_cancel (rh);
1301 rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
1307 * Process a records that were decrypted from a block.
1309 * @param cls closure with the `struct GNS_ResolverHandle`
1310 * @param rd_count number of entries in @a rd array
1311 * @param rd array of records with data to store
1314 handle_gns_resolution_result (void *cls,
1315 unsigned int rd_count,
1316 const struct GNUNET_GNSRECORD_Data *rd)
1318 struct GNS_ResolverHandle *rh = cls;
1319 struct AuthorityChain *ac;
1322 struct VpnContext *vpn_ctx;
1323 const struct GNUNET_TUN_GnsVpnRecord *vpn;
1325 struct GNUNET_HashCode vhash;
1327 char scratch[UINT16_MAX];
1329 size_t scratch_start;
1331 struct GNUNET_GNSRECORD_Data rd_new[rd_count];
1332 unsigned int rd_off;
1334 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1335 "Resolution succeeded for `%s' in zone %s, got %u records\n",
1337 GNUNET_GNSRECORD_z2s (&rh->ac_tail->authority_info.gns_authority),
1339 if (0 == rh->name_resolution_pos)
1341 /* top-level match, are we done yet? */
1342 if ( (rd_count > 0) &&
1343 (GNUNET_DNSPARSER_TYPE_CNAME == rd[0].record_type) &&
1344 (GNUNET_DNSPARSER_TYPE_CNAME != rh->record_type) )
1347 cname = GNUNET_DNSPARSER_parse_name (rd[0].data,
1350 if ( (NULL == cname) ||
1351 (off != rd[0].data_size) )
1353 GNUNET_break_op (0);
1354 rh->proc (rh->proc_cls, 0, NULL);
1355 GNS_resolver_lookup_cancel (rh);
1356 GNUNET_free_non_null (cname);
1359 handle_gns_cname_result (rh,
1361 GNUNET_free (cname);
1364 /* If A/AAAA was requested, but we got a VPN
1365 record, we convert it to A/AAAA using GNUnet VPN */
1366 if ( (GNUNET_DNSPARSER_TYPE_A == rh->record_type) ||
1367 (GNUNET_DNSPARSER_TYPE_AAAA == rh->record_type) )
1369 for (i=0;i<rd_count;i++)
1371 switch (rd[i].record_type)
1373 case GNUNET_GNSRECORD_TYPE_VPN:
1375 af = (GNUNET_DNSPARSER_TYPE_A == rh->record_type) ? AF_INET : AF_INET6;
1376 if (sizeof (struct GNUNET_TUN_GnsVpnRecord) <
1379 GNUNET_break_op (0);
1380 rh->proc (rh->proc_cls, 0, NULL);
1381 GNS_resolver_lookup_cancel (rh);
1384 vpn = (const struct GNUNET_TUN_GnsVpnRecord *) rd[i].data;
1385 vname = (const char *) &vpn[1];
1386 if ('\0' != vname[rd[i].data_size - 1 - sizeof (struct GNUNET_TUN_GnsVpnRecord)])
1388 GNUNET_break_op (0);
1389 rh->proc (rh->proc_cls, 0, NULL);
1390 GNS_resolver_lookup_cancel (rh);
1393 GNUNET_CRYPTO_hash (vname,
1394 strlen (vname), // FIXME: +1?
1396 vpn_ctx = GNUNET_new (struct VpnContext);
1397 rh->vpn_ctx = vpn_ctx;
1399 vpn_ctx->rd_data_size = GNUNET_GNSRECORD_records_get_size (rd_count,
1401 vpn_ctx->rd_data = GNUNET_malloc (vpn_ctx->rd_data_size);
1402 (void) GNUNET_GNSRECORD_records_serialize (rd_count,
1404 vpn_ctx->rd_data_size,
1406 vpn_ctx->vpn_request = GNUNET_VPN_redirect_to_peer (vpn_handle,
1411 GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT),
1416 case GNUNET_GNSRECORD_TYPE_GNS2DNS:
1418 /* delegation to DNS */
1419 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1420 "Found GNS2DNS record, delegating to DNS!\n");
1428 /* convert relative names in record values to absolute names,
1429 using 'scratch' array for memory allocations */
1432 for (i=0;i<rd_count;i++)
1434 rd_new[rd_off] = rd[i];
1435 /* Check if the embedded name(s) end in "+", and if so,
1436 replace the "+" with the zone at "ac_tail", changing the name
1437 to a ".zkey". The name is allocated on the 'scratch' array,
1438 so we can free it afterwards. */
1439 switch (rd[i].record_type)
1441 case GNUNET_DNSPARSER_TYPE_CNAME:
1446 cname = GNUNET_DNSPARSER_parse_name (rd[i].data,
1449 if ( (NULL == cname) ||
1450 (off != rd[i].data_size) )
1452 GNUNET_break_op (0); /* record not well-formed */
1456 cname = translate_dot_plus (rh, cname);
1457 GNUNET_break (NULL != cname);
1458 scratch_start = scratch_off;
1460 GNUNET_DNSPARSER_builder_add_name (scratch,
1469 rd_new[rd_off].data = &scratch[scratch_start];
1470 rd_new[rd_off].data_size = scratch_off - scratch_start;
1474 GNUNET_free_non_null (cname);
1477 case GNUNET_DNSPARSER_TYPE_SOA:
1479 struct GNUNET_DNSPARSER_SoaRecord *soa;
1482 soa = GNUNET_DNSPARSER_parse_soa (rd[i].data,
1485 if ( (NULL == soa) ||
1486 (off != rd[i].data_size) )
1488 GNUNET_break_op (0); /* record not well-formed */
1492 soa->mname = translate_dot_plus (rh, soa->mname);
1493 soa->rname = translate_dot_plus (rh, soa->rname);
1494 scratch_start = scratch_off;
1496 GNUNET_DNSPARSER_builder_add_soa (scratch,
1505 rd_new[rd_off].data = &scratch[scratch_start];
1506 rd_new[rd_off].data_size = scratch_off - scratch_start;
1511 GNUNET_DNSPARSER_free_soa (soa);
1514 case GNUNET_DNSPARSER_TYPE_MX:
1516 struct GNUNET_DNSPARSER_MxRecord *mx;
1519 mx = GNUNET_DNSPARSER_parse_mx (rd[i].data,
1522 if ( (NULL == mx) ||
1523 (off != rd[i].data_size) )
1525 GNUNET_break_op (0); /* record not well-formed */
1529 mx->mxhost = translate_dot_plus (rh, mx->mxhost);
1530 scratch_start = scratch_off;
1532 GNUNET_DNSPARSER_builder_add_mx (scratch,
1541 rd_new[rd_off].data = &scratch[scratch_start];
1542 rd_new[rd_off].data_size = scratch_off - scratch_start;
1547 GNUNET_DNSPARSER_free_mx (mx);
1550 case GNUNET_DNSPARSER_TYPE_SRV:
1552 struct GNUNET_DNSPARSER_SrvRecord *srv;
1555 /* FIXME: passing rh->name here is is not necessarily what we want
1556 (SRV support not finished) */
1557 srv = GNUNET_DNSPARSER_parse_srv (rh->name,
1561 if ( (NULL == srv) ||
1562 (off != rd[i].data_size) )
1564 GNUNET_break_op (0); /* record not well-formed */
1568 srv->domain_name = translate_dot_plus (rh, srv->domain_name);
1569 srv->target = translate_dot_plus (rh, srv->target);
1570 scratch_start = scratch_off;
1572 GNUNET_DNSPARSER_builder_add_srv (scratch,
1581 rd_new[rd_off].data = &scratch[scratch_start];
1582 rd_new[rd_off].data_size = scratch_off - scratch_start;
1587 GNUNET_DNSPARSER_free_srv (srv);
1590 case GNUNET_GNSRECORD_TYPE_PKEY:
1592 struct GNUNET_CRYPTO_EcdsaPublicKey pub;
1594 if (rd[i].data_size != sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey))
1596 GNUNET_break_op (0);
1599 memcpy (&pub, rd[i].data, rd[i].data_size);
1601 /* tigger shortening */
1602 if (NULL != rh->shorten_key)
1604 GNS_shorten_start (rh->ac_tail->label,
1609 if (GNUNET_GNSRECORD_TYPE_PKEY != rh->record_type)
1611 /* try to resolve "+" */
1612 struct AuthorityChain *ac;
1614 ac = GNUNET_new (struct AuthorityChain);
1616 ac->gns_authority = GNUNET_YES;
1617 ac->authority_info.gns_authority = pub;
1618 ac->label = GNUNET_strdup (GNUNET_GNS_MASTERZONE_STR);
1619 GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
1622 rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
1628 case GNUNET_GNSRECORD_TYPE_GNS2DNS:
1630 /* delegation to DNS */
1631 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1632 "Found GNS2DNS record, delegating to DNS!\n");
1641 /* yes, we are done, return result */
1642 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1643 "Returning GNS response for `%s' with %u answers\n",
1646 rh->proc (rh->proc_cls, rd_off, rd_new);
1647 GNS_resolver_lookup_cancel (rh);
1651 /* need to recurse, check if we can */
1652 for (i=0;i<rd_count;i++)
1654 switch (rd[i].record_type)
1656 case GNUNET_GNSRECORD_TYPE_PKEY:
1657 /* delegation to another zone */
1658 if (sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) !=
1661 GNUNET_break_op (0);
1662 rh->proc (rh->proc_cls, 0, NULL);
1663 GNS_resolver_lookup_cancel (rh);
1666 /* expand authority chain */
1667 ac = GNUNET_new (struct AuthorityChain);
1669 ac->gns_authority = GNUNET_YES;
1670 memcpy (&ac->authority_info.gns_authority,
1672 sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey));
1673 ac->label = resolver_lookup_get_next_label (rh);
1674 /* tigger shortening */
1675 if (NULL != rh->shorten_key)
1676 GNS_shorten_start (rh->ac_tail->label,
1677 &ac->authority_info.gns_authority,
1679 /* add AC to tail */
1680 GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
1684 rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
1687 case GNUNET_GNSRECORD_TYPE_GNS2DNS:
1689 /* resolution continues within DNS */
1690 struct Gns2DnsContext *g2dc;
1696 cp = GNUNET_strndup (rd[i].data,
1698 at = strchr (cp, '@');
1701 GNUNET_break_op (0);
1702 rh->proc (rh->proc_cls, 0, NULL);
1703 GNS_resolver_lookup_cancel (rh);
1708 ns = GNUNET_DNSPARSER_parse_name (cp,
1711 if ( (NULL == ns) ||
1712 (off != strlen (cp)) )
1714 GNUNET_break_op (0); /* record not well-formed */
1715 rh->proc (rh->proc_cls, 0, NULL);
1716 GNS_resolver_lookup_cancel (rh);
1720 off++; /* skip '@' */
1721 ip = GNUNET_DNSPARSER_parse_name (cp,
1724 if ( (NULL == ip) ||
1725 (off != rd[i].data_size) )
1727 GNUNET_break_op (0); /* record not well-formed */
1728 rh->proc (rh->proc_cls, 0, NULL);
1729 GNS_resolver_lookup_cancel (rh);
1735 /* resolve 'ip' to determine the IP(s) of the DNS
1737 g2dc = GNUNET_new (struct Gns2DnsContext);
1739 g2dc->rh = GNUNET_new (struct GNS_ResolverHandle);
1740 g2dc->rh->authority_zone = rh->ac_tail->authority_info.gns_authority;
1741 g2dc->rh->name = ip;
1742 g2dc->rh->name_resolution_pos = strlen (ip);
1743 g2dc->rh->proc = &handle_gns2dns_result;
1744 g2dc->rh->proc_cls = rh;
1745 g2dc->rh->record_type = GNUNET_GNSRECORD_TYPE_ANY;
1746 g2dc->rh->only_cached = GNUNET_NO;
1747 g2dc->rh->loop_limiter = rh->loop_limiter + 1;
1749 start_resolver_lookup (g2dc->rh);
1752 case GNUNET_DNSPARSER_TYPE_CNAME:
1757 cname = GNUNET_DNSPARSER_parse_name (rd[i].data,
1760 if ( (NULL == cname) ||
1761 (off != rd[i].data_size) )
1763 GNUNET_break_op (0); /* record not well-formed */
1764 rh->proc (rh->proc_cls, 0, NULL);
1765 GNS_resolver_lookup_cancel (rh);
1766 GNUNET_free_non_null (cname);
1769 handle_gns_cname_result (rh,
1771 GNUNET_free (cname);
1774 /* FIXME: handle DNAME */
1780 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1781 _("GNS lookup recursion failed (no delegation record found)\n"));
1782 rh->proc (rh->proc_cls, 0, NULL);
1783 GNS_resolver_lookup_cancel (rh);
1788 * Function called once the namestore has completed the request for
1791 * @param cls closure with the `struct CacheOps`
1792 * @param success #GNUNET_OK on success
1793 * @param emsg error message
1796 namecache_cache_continuation (void *cls,
1800 struct CacheOps *co = cls;
1802 co->namecache_qe_cache = NULL;
1804 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1805 _("Failed to cache GNS resolution: %s\n"),
1807 GNUNET_CONTAINER_DLL_remove (co_head,
1815 * Iterator called on each result obtained for a DHT
1816 * operation that expects a reply
1818 * @param cls closure with the `struct GNS_ResolverHandle`
1819 * @param exp when will this value expire
1820 * @param key key of the result
1821 * @param get_path peers on reply path (or NULL if not recorded)
1822 * [0] = datastore's first neighbor, [length - 1] = local peer
1823 * @param get_path_length number of entries in @a get_path
1824 * @param put_path peers on the PUT path (or NULL if not recorded)
1825 * [0] = origin, [length - 1] = datastore
1826 * @param put_path_length number of entries in @a put_path
1827 * @param type type of the result
1828 * @param size number of bytes in data
1829 * @param data pointer to the result data
1832 handle_dht_response (void *cls,
1833 struct GNUNET_TIME_Absolute exp,
1834 const struct GNUNET_HashCode *key,
1835 const struct GNUNET_PeerIdentity *get_path,
1836 unsigned int get_path_length,
1837 const struct GNUNET_PeerIdentity *put_path,
1838 unsigned int put_path_length,
1839 enum GNUNET_BLOCK_Type type,
1840 size_t size, const void *data)
1842 struct GNS_ResolverHandle *rh = cls;
1843 struct AuthorityChain *ac = rh->ac_tail;
1844 const struct GNUNET_GNSRECORD_Block *block;
1845 struct CacheOps *co;
1847 GNUNET_DHT_get_stop (rh->get_handle);
1848 rh->get_handle = NULL;
1849 GNUNET_CONTAINER_heap_remove_node (rh->dht_heap_node);
1850 rh->dht_heap_node = NULL;
1851 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1852 "Handling response from the DHT\n");
1853 if (size < sizeof (struct GNUNET_GNSRECORD_Block))
1855 /* how did this pass DHT block validation!? */
1857 rh->proc (rh->proc_cls, 0, NULL);
1858 GNS_resolver_lookup_cancel (rh);
1863 ntohl (block->purpose.size) +
1864 sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) +
1865 sizeof (struct GNUNET_CRYPTO_EcdsaSignature))
1867 /* how did this pass DHT block validation!? */
1869 rh->proc (rh->proc_cls, 0, NULL);
1870 GNS_resolver_lookup_cancel (rh);
1874 GNUNET_GNSRECORD_block_decrypt (block,
1875 &ac->authority_info.gns_authority,
1877 &handle_gns_resolution_result,
1880 GNUNET_break_op (0); /* block was ill-formed */
1881 rh->proc (rh->proc_cls, 0, NULL);
1882 GNS_resolver_lookup_cancel (rh);
1885 if (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (block->expiration_time)).rel_value_us)
1887 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1888 "Received expired block from the DHT, will not cache it.\n");
1891 /* Cache well-formed blocks */
1892 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1893 "Caching response from the DHT in namestore\n");
1894 co = GNUNET_new (struct CacheOps);
1895 co->namecache_qe_cache = GNUNET_NAMECACHE_block_cache (namecache_handle,
1897 &namecache_cache_continuation,
1899 GNUNET_CONTAINER_DLL_insert (co_head,
1906 * Process a record that was stored in the namestore.
1908 * @param cls closure with the `struct GNS_ResolverHandle`
1909 * @param block block that was stored in the namestore
1912 handle_namestore_block_response (void *cls,
1913 const struct GNUNET_GNSRECORD_Block *block)
1915 struct GNS_ResolverHandle *rh = cls;
1916 struct GNS_ResolverHandle *rx;
1917 struct AuthorityChain *ac = rh->ac_tail;
1918 const char *label = ac->label;
1919 const struct GNUNET_CRYPTO_EcdsaPublicKey *auth = &ac->authority_info.gns_authority;
1920 struct GNUNET_HashCode query;
1922 GNUNET_GNSRECORD_query_from_public_key (auth,
1925 GNUNET_assert (NULL != rh->namecache_qe);
1926 rh->namecache_qe = NULL;
1927 if ( (GNUNET_NO == rh->only_cached) &&
1928 ( (NULL == block) ||
1929 (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (block->expiration_time)).rel_value_us) ) )
1931 /* Namestore knows nothing; try DHT lookup */
1932 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1933 "Starting DHT lookup for `%s' in zone %s\n",
1935 GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
1936 GNUNET_assert (NULL == rh->get_handle);
1937 rh->get_handle = GNUNET_DHT_get_start (dht_handle,
1938 GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
1940 DHT_GNS_REPLICATION_LEVEL,
1941 GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
1943 &handle_dht_response, rh);
1944 rh->dht_heap_node = GNUNET_CONTAINER_heap_insert (dht_lookup_heap,
1946 GNUNET_TIME_absolute_get ().abs_value_us);
1947 if (GNUNET_CONTAINER_heap_get_size (dht_lookup_heap) > max_allowed_background_queries)
1949 /* fail longest-standing DHT request */
1950 rx = GNUNET_CONTAINER_heap_peek (dht_lookup_heap);
1951 GNUNET_assert (NULL != rx);
1952 rx->proc (rx->proc_cls, 0, NULL);
1953 GNS_resolver_lookup_cancel (rx);
1957 if ( (NULL == block) ||
1958 (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (block->expiration_time)).rel_value_us) )
1960 /* DHT not permitted and no local result, fail */
1961 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1962 "Resolution failed for `%s' in zone %s (DHT lookup not permitted by configuration)\n",
1964 GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
1965 rh->proc (rh->proc_cls, 0, NULL);
1966 GNS_resolver_lookup_cancel (rh);
1970 GNUNET_GNSRECORD_block_decrypt (block,
1973 &handle_gns_resolution_result,
1976 GNUNET_break_op (0); /* block was ill-formed */
1977 rh->proc (rh->proc_cls, 0, NULL);
1978 GNS_resolver_lookup_cancel (rh);
1985 * Lookup tail of our authority chain in the namestore.
1987 * @param rh query we are processing
1990 recursive_gns_resolution_namestore (struct GNS_ResolverHandle *rh)
1992 struct AuthorityChain *ac = rh->ac_tail;
1993 struct GNUNET_HashCode query;
1995 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1996 "Starting GNS resolution for `%s' in zone %s\n",
1998 GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
1999 GNUNET_GNSRECORD_query_from_public_key (&ac->authority_info.gns_authority,
2002 rh->namecache_qe = GNUNET_NAMECACHE_lookup_block (namecache_handle,
2004 &handle_namestore_block_response,
2006 GNUNET_assert (NULL != rh->namecache_qe);
2011 * Function called with the result from a revocation check.
2013 * @param cls the `struct GNS_ResovlerHandle`
2014 * @param is_valid #GNUNET_YES if the zone was not yet revoked
2017 handle_revocation_result (void *cls,
2020 struct GNS_ResolverHandle *rh = cls;
2021 struct AuthorityChain *ac = rh->ac_tail;
2023 rh->rev_check = NULL;
2024 if (GNUNET_YES != is_valid)
2026 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2027 _("Zone %s was revoked, resolution fails\n"),
2028 GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
2029 rh->proc (rh->proc_cls, 0, NULL);
2030 GNS_resolver_lookup_cancel (rh);
2033 recursive_gns_resolution_namestore (rh);
2038 * Perform revocation check on tail of our authority chain.
2040 * @param rh query we are processing
2043 recursive_gns_resolution_revocation (struct GNS_ResolverHandle *rh)
2045 struct AuthorityChain *ac = rh->ac_tail;
2047 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2048 "Starting revocation check for zone %s\n",
2049 GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
2050 rh->rev_check = GNUNET_REVOCATION_query (cfg,
2051 &ac->authority_info.gns_authority,
2052 &handle_revocation_result,
2054 GNUNET_assert (NULL != rh->rev_check);
2059 * Task scheduled to continue with the resolution process.
2061 * @param cls the `struct GNS_ResolverHandle` of the resolution
2062 * @param tc task context
2065 recursive_resolution (void *cls,
2066 const struct GNUNET_SCHEDULER_TaskContext *tc)
2068 struct GNS_ResolverHandle *rh = cls;
2070 rh->task_id = GNUNET_SCHEDULER_NO_TASK;
2071 if (MAX_RECURSION < rh->loop_limiter++)
2073 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2074 "Encountered unbounded recursion resolving `%s'\n",
2076 rh->proc (rh->proc_cls, 0, NULL);
2077 GNS_resolver_lookup_cancel (rh);
2080 if (GNUNET_YES == rh->ac_tail->gns_authority)
2081 recursive_gns_resolution_revocation (rh);
2083 recursive_dns_resolution (rh);
2088 * Begin the resolution process from 'name', starting with
2089 * the identification of the zone specified by 'name'.
2091 * @param rh resolution to perform
2094 start_resolver_lookup (struct GNS_ResolverHandle *rh)
2096 struct AuthorityChain *ac;
2101 if (1 == inet_pton (AF_INET,
2105 /* name is IPv4 address, pretend it's an A record */
2106 struct GNUNET_GNSRECORD_Data rd;
2109 rd.data_size = sizeof (v4);
2110 rd.expiration_time = UINT64_MAX;
2111 rd.record_type = GNUNET_DNSPARSER_TYPE_A;
2113 rh->proc (rh->proc_cls, 1, &rd);
2114 GNS_resolver_lookup_cancel (rh);
2117 if (1 == inet_pton (AF_INET6,
2121 /* name is IPv6 address, pretend it's an AAAA record */
2122 struct GNUNET_GNSRECORD_Data rd;
2125 rd.data_size = sizeof (v6);
2126 rd.expiration_time = UINT64_MAX;
2127 rd.record_type = GNUNET_DNSPARSER_TYPE_AAAA;
2129 rh->proc (rh->proc_cls, 1, &rd);
2130 GNS_resolver_lookup_cancel (rh);
2133 if ( ( (GNUNET_YES == is_canonical (rh->name)) &&
2134 (0 != strcmp (GNUNET_GNS_TLD, rh->name)) ) ||
2135 ( (GNUNET_YES != is_gnu_tld (rh->name)) &&
2136 (GNUNET_YES != is_zkey_tld (rh->name)) ) )
2138 /* use standard DNS lookup */
2141 switch (rh->record_type)
2143 case GNUNET_DNSPARSER_TYPE_A:
2146 case GNUNET_DNSPARSER_TYPE_AAAA:
2153 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2154 "Doing standard DNS lookup for `%s'\n",
2156 rh->std_resolve = GNUNET_RESOLVER_ip_get (rh->name,
2163 if (is_zkey_tld (rh->name))
2165 /* Name ends with ".zkey", try to replace authority zone with zkey
2167 GNUNET_free (resolver_lookup_get_next_label (rh)); /* will return "zkey" */
2168 y = resolver_lookup_get_next_label (rh); /* will return 'y' coordinate */
2171 GNUNET_CRYPTO_ecdsa_public_key_from_string (y,
2173 &rh->authority_zone)) )
2175 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2176 _("Hostname `%s' is not well-formed, resolution fails\n"),
2178 rh->task_id = GNUNET_SCHEDULER_add_now (&fail_resolution, rh);
2180 GNUNET_free_non_null (y);
2184 /* Name ends with ".gnu", eat ".gnu" and continue with resolution */
2185 GNUNET_free (resolver_lookup_get_next_label (rh));
2187 ac = GNUNET_new (struct AuthorityChain);
2189 ac->label = resolver_lookup_get_next_label (rh);
2190 if (NULL == ac->label)
2191 /* name was just "gnu", so we default to label '+' */
2192 ac->label = GNUNET_strdup (GNUNET_GNS_MASTERZONE_STR);
2193 ac->gns_authority = GNUNET_YES;
2194 ac->authority_info.gns_authority = rh->authority_zone;
2195 GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
2198 rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
2204 * Lookup of a record in a specific zone calls lookup result processor
2207 * @param zone the zone to perform the lookup in
2208 * @param record_type the record type to look up
2209 * @param name the name to look up
2210 * @param shorten_key a private key for use with PSEU import (can be NULL)
2211 * @param only_cached #GNUNET_NO to only check locally not DHT for performance
2212 * @param proc the processor to call on result
2213 * @param proc_cls the closure to pass to @a proc
2214 * @return handle to cancel operation
2216 struct GNS_ResolverHandle *
2217 GNS_resolver_lookup (const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
2218 uint32_t record_type,
2220 const struct GNUNET_CRYPTO_EcdsaPrivateKey *shorten_key,
2222 GNS_ResultProcessor proc, void *proc_cls)
2224 struct GNS_ResolverHandle *rh;
2226 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2227 (NULL == shorten_key)
2228 ? "Starting lookup for `%s' with shortening disabled\n"
2229 : "Starting lookup for `%s' with shortening enabled\n",
2231 rh = GNUNET_new (struct GNS_ResolverHandle);
2232 GNUNET_CONTAINER_DLL_insert (rlh_head,
2235 rh->authority_zone = *zone;
2237 rh->proc_cls = proc_cls;
2238 rh->only_cached = only_cached;
2239 rh->record_type = record_type;
2240 rh->name = GNUNET_strdup (name);
2241 rh->name_resolution_pos = strlen (name);
2242 if (NULL != shorten_key)
2244 rh->shorten_key = GNUNET_new (struct GNUNET_CRYPTO_EcdsaPrivateKey);
2245 *rh->shorten_key = *shorten_key;
2247 start_resolver_lookup (rh);
2253 * Cancel active resolution (i.e. client disconnected).
2255 * @param rh resolution to abort
2258 GNS_resolver_lookup_cancel (struct GNS_ResolverHandle *rh)
2260 struct DnsResult *dr;
2261 struct AuthorityChain *ac;
2262 struct VpnContext *vpn_ctx;
2264 GNUNET_CONTAINER_DLL_remove (rlh_head,
2267 while (NULL != (ac = rh->ac_head))
2269 GNUNET_CONTAINER_DLL_remove (rh->ac_head,
2272 GNUNET_free (ac->label);
2275 if (NULL != rh->g2dc)
2277 /* rh->g2dc->rh is NOT in the DLL yet, so to enable us
2278 using GNS_resolver_lookup_cancel here, we need to
2280 if (NULL != rh->g2dc->rh)
2282 GNUNET_CONTAINER_DLL_insert (rlh_head,
2285 GNS_resolver_lookup_cancel (rh->g2dc->rh);
2286 rh->g2dc->rh = NULL;
2288 GNUNET_free (rh->g2dc->ns);
2289 GNUNET_free (rh->g2dc);
2292 if (GNUNET_SCHEDULER_NO_TASK != rh->task_id)
2294 GNUNET_SCHEDULER_cancel (rh->task_id);
2295 rh->task_id = GNUNET_SCHEDULER_NO_TASK;
2297 if (NULL != rh->get_handle)
2299 GNUNET_DHT_get_stop (rh->get_handle);
2300 rh->get_handle = NULL;
2302 if (NULL != rh->dht_heap_node)
2304 GNUNET_CONTAINER_heap_remove_node (rh->dht_heap_node);
2305 rh->dht_heap_node = NULL;
2307 if (NULL != (vpn_ctx = rh->vpn_ctx))
2309 GNUNET_VPN_cancel_request (vpn_ctx->vpn_request);
2310 GNUNET_free (vpn_ctx->rd_data);
2311 GNUNET_free (vpn_ctx);
2313 if (NULL != rh->dns_request)
2315 GNUNET_DNSSTUB_resolve_cancel (rh->dns_request);
2316 rh->dns_request = NULL;
2318 if (NULL != rh->namecache_qe)
2320 GNUNET_NAMECACHE_cancel (rh->namecache_qe);
2321 rh->namecache_qe = NULL;
2323 if (NULL != rh->rev_check)
2325 GNUNET_REVOCATION_query_cancel (rh->rev_check);
2326 rh->rev_check = NULL;
2328 if (NULL != rh->std_resolve)
2330 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2331 "Canceling standard DNS resolution\n");
2332 GNUNET_RESOLVER_request_cancel (rh->std_resolve);
2333 rh->std_resolve = NULL;
2335 while (NULL != (dr = rh->dns_result_head))
2337 GNUNET_CONTAINER_DLL_remove (rh->dns_result_head,
2338 rh->dns_result_tail,
2342 GNUNET_free_non_null (rh->shorten_key);
2343 GNUNET_free (rh->name);
2348 /* ***************** Resolver initialization ********************* */
2352 * Initialize the resolver
2354 * @param nc the namecache handle
2355 * @param dht the dht handle
2356 * @param c configuration handle
2357 * @param max_bg_queries maximum number of parallel background queries in dht
2360 GNS_resolver_init (struct GNUNET_NAMECACHE_Handle *nc,
2361 struct GNUNET_DHT_Handle *dht,
2362 const struct GNUNET_CONFIGURATION_Handle *c,
2363 unsigned long long max_bg_queries)
2368 namecache_handle = nc;
2371 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
2372 max_allowed_background_queries = max_bg_queries;
2374 GNUNET_CONFIGURATION_get_value_string (c,
2379 /* user did not specify DNS resolver, use 8.8.8.8 */
2380 dns_ip = GNUNET_strdup ("8.8.8.8");
2382 dns_handle = GNUNET_DNSSTUB_start (dns_ip);
2383 GNUNET_free (dns_ip);
2384 vpn_handle = GNUNET_VPN_connect (cfg);
2392 GNS_resolver_done ()
2394 struct GNS_ResolverHandle *rh;
2395 struct CacheOps *co;
2397 /* abort active resolutions */
2398 while (NULL != (rh = rlh_head))
2400 rh->proc (rh->proc_cls, 0, NULL);
2401 GNS_resolver_lookup_cancel (rh);
2403 while (NULL != (co = co_head))
2405 GNUNET_CONTAINER_DLL_remove (co_head,
2408 GNUNET_NAMECACHE_cancel (co->namecache_qe_cache);
2411 GNUNET_CONTAINER_heap_destroy (dht_lookup_heap);
2412 dht_lookup_heap = NULL;
2413 GNUNET_DNSSTUB_stop (dns_handle);
2415 GNUNET_VPN_disconnect (vpn_handle);
2418 namecache_handle = NULL;
2422 /* *************** common helper functions (do not really belong here) *********** */
2425 * Checks if @a name ends in ".TLD"
2427 * @param name the name to check
2428 * @param tld the TLD to check for
2429 * @return GNUNET_YES or GNUNET_NO
2432 is_tld (const char* name, const char* tld)
2436 if (strlen (name) <= strlen (tld))
2438 offset = strlen (name) - strlen (tld);
2439 if (0 != strcmp (name + offset, tld))
2445 /* end of gnunet-service-gns_resolver.c */