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- /*
- This file is part of GNUnet.
- (C) 2011-2013 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 gns/gnunet-service-gns_resolver.c
- * @brief GNU Name System resolver logic
- * @author Martin Schanzenbach
- * @author Christian Grothoff
- */
- #include "platform.h"
- #include "gnunet_util_lib.h"
- #include "gnunet_dnsstub_lib.h"
- #include "gnunet_dht_service.h"
- #include "gnunet_gnsrecord_lib.h"
- #include "gnunet_namecache_service.h"
- #include "gnunet_namestore_service.h"
- #include "gnunet_dns_service.h"
- #include "gnunet_resolver_service.h"
- #include "gnunet_revocation_service.h"
- #include "gnunet_dnsparser_lib.h"
- #include "gnunet_tun_lib.h"
- #include "gnunet_gns_service.h"
- #include "gns.h"
- #include "gnunet-service-gns_resolver.h"
- #include "gnunet-service-gns_shorten.h"
- #include "gnunet_vpn_service.h"
- /**
- * Default DHT timeout for lookups.
- */
- #define DHT_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)
- /**
- * Default timeout for DNS lookups.
- */
- #define DNS_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
- /**
- * Default timeout for VPN redirections.
- */
- #define VPN_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30)
- /**
- * DHT replication level
- */
- #define DHT_GNS_REPLICATION_LEVEL 5
- /**
- * How deep do we allow recursions to go before we abort?
- */
- #define MAX_RECURSION 256
- /**
- * DLL to hold the authority chain we had to pass in the resolution
- * process.
- */
- struct AuthorityChain
- {
- /**
- * This is a DLL.
- */
- struct AuthorityChain *prev;
- /**
- * This is a DLL.
- */
- struct AuthorityChain *next;
- /**
- * Resolver handle this entry in the chain belongs to.
- */
- struct GNS_ResolverHandle *rh;
- /**
- * label/name corresponding to the authority
- */
- char *label;
- /**
- * label/name suggested for shortening to the authority
- */
- char *suggested_shortening_label;
- /**
- * Do we already try to shorten this authority?
- */
- int shortening_started;
- /**
- * #GNUNET_YES if the authority was a GNS authority,
- * #GNUNET_NO if the authority was a DNS authority.
- */
- int gns_authority;
- /**
- * Information about the resolver authority for this label.
- */
- union
- {
- /**
- * The zone of the GNS authority
- */
- struct GNUNET_CRYPTO_EcdsaPublicKey gns_authority;
- struct
- {
- /**
- * Domain of the DNS resolver that is the authority.
- * (appended to construct the DNS name to resolve;
- * this is NOT the DNS name of the DNS server!).
- */
- char name[GNUNET_DNSPARSER_MAX_NAME_LENGTH + 1];
- /**
- * IP address of the DNS resolver that is authoritative.
- * (this implementation currently only supports one
- * IP at a time).
- */
- struct sockaddr_storage dns_ip;
- } dns_authority;
- } authority_info;
- };
- /**
- * A result we got from DNS.
- */
- struct DnsResult
- {
- /**
- * Kept in DLL.
- */
- struct DnsResult *next;
- /**
- * Kept in DLL.
- */
- struct DnsResult *prev;
- /**
- * Binary value stored in the DNS record (appended to this struct)
- */
- const void *data;
- /**
- * Expiration time for the DNS record, 0 if we didn't
- * get anything useful (i.e. 'gethostbyname' was used).
- */
- uint64_t expiration_time;
- /**
- * Number of bytes in @e data.
- */
- size_t data_size;
- /**
- * Type of the GNS/DNS record.
- */
- uint32_t record_type;
- };
- /**
- * Closure for #vpn_allocation_cb.
- */
- struct VpnContext
- {
- /**
- * Which resolution process are we processing.
- */
- struct GNS_ResolverHandle *rh;
- /**
- * Handle to the VPN request that we were performing.
- */
- struct GNUNET_VPN_RedirectionRequest *vpn_request;
- /**
- * Number of records serialized in @e rd_data.
- */
- unsigned int rd_count;
- /**
- * Serialized records.
- */
- char *rd_data;
- /**
- * Number of bytes in @e rd_data.
- */
- size_t rd_data_size;
- };
- /**
- * Information we keep during the resolution of an
- * IP address for a DNS server while handling a
- * GNS2DNS record.
- */
- struct Gns2DnsContext
- {
- /**
- * DNS domain in which the resolution will continue
- * (first part of the GNS2DNS record).
- */
- char *ns;
- /**
- * Handle for the resolution of the IP part of the
- * GNS2DNS record. Will return to us the addresses
- * of the DNS resolver to use.
- */
- struct GNS_ResolverHandle *rh;
- };
- /**
- * Handle to a currenty pending resolution. On result (positive or
- * negative) the #GNS_ResultProcessor is called.
- */
- struct GNS_ResolverHandle
- {
- /**
- * DLL
- */
- struct GNS_ResolverHandle *next;
- /**
- * DLL
- */
- struct GNS_ResolverHandle *prev;
- /**
- * The top-level GNS authoritative zone to query
- */
- struct GNUNET_CRYPTO_EcdsaPublicKey authority_zone;
- /**
- * called when resolution phase finishes
- */
- GNS_ResultProcessor proc;
- /**
- * closure passed to @e proc
- */
- void* proc_cls;
- /**
- * Handle used during GNS2DNS resolution for looking up the
- * IP address of the DNS server.
- */
- struct Gns2DnsContext *g2dc;
- /**
- * Handle for DHT lookups. should be NULL if no lookups are in progress
- */
- struct GNUNET_DHT_GetHandle *get_handle;
- /**
- * Handle to a VPN request, NULL if none is active.
- */
- struct VpnContext *vpn_ctx;
- /**
- * Socket for a DNS request, NULL if none is active.
- */
- struct GNUNET_DNSSTUB_RequestSocket *dns_request;
- /**
- * Handle for standard DNS resolution, NULL if none is active.
- */
- struct GNUNET_RESOLVER_RequestHandle *std_resolve;
- /**
- * Pending Namecache lookup task
- */
- struct GNUNET_NAMECACHE_QueueEntry *namecache_qe;
- /**
- * Pending revocation check.
- */
- struct GNUNET_REVOCATION_Query *rev_check;
- /**
- * Heap node associated with this lookup. Used to limit number of
- * concurrent requests.
- */
- struct GNUNET_CONTAINER_HeapNode *dht_heap_node;
- /**
- * DLL to store the authority chain
- */
- struct AuthorityChain *ac_head;
- /**
- * DLL to store the authority chain
- */
- struct AuthorityChain *ac_tail;
- /**
- * Private key of the shorten zone, NULL to not shorten.
- */
- struct GNUNET_CRYPTO_EcdsaPrivateKey *shorten_key;
- /**
- * ID of a task associated with the resolution process.
- */
- GNUNET_SCHEDULER_TaskIdentifier task_id;
- /**
- * The name to resolve
- */
- char *name;
- /**
- * DLL of results we got from DNS.
- */
- struct DnsResult *dns_result_head;
- /**
- * DLL of results we got from DNS.
- */
- struct DnsResult *dns_result_tail;
- /**
- * Current offset in 'name' where we are resolving.
- */
- size_t name_resolution_pos;
- /**
- * Use only cache
- */
- enum GNUNET_GNS_LocalOptions options;
- /**
- * For SRV and TLSA records, the number of the
- * protocol specified in the name. 0 if no protocol was given.
- */
- int protocol;
- /**
- * For SRV and TLSA records, the number of the
- * service specified in the name. 0 if no service was given.
- */
- int service;
- /**
- * Desired type for the resolution.
- */
- int record_type;
- /**
- * We increment the loop limiter for each step in a recursive
- * resolution. If it passes our threshold (i.e. due to
- * self-recursion in the resolution, i.e CNAME fun), we stop.
- */
- unsigned int loop_limiter;
- };
- /**
- * Active namestore caching operations.
- */
- struct CacheOps
- {
- /**
- * Organized in a DLL.
- */
- struct CacheOps *next;
- /**
- * Organized in a DLL.
- */
- struct CacheOps *prev;
- /**
- * Pending Namestore caching task.
- */
- struct GNUNET_NAMECACHE_QueueEntry *namecache_qe_cache;
- };
- /**
- * Our handle to the namecache service
- */
- static struct GNUNET_NAMECACHE_Handle *namecache_handle;
- /**
- * Our handle to the vpn service
- */
- static struct GNUNET_VPN_Handle *vpn_handle;
- /**
- * Resolver handle to the dht
- */
- static struct GNUNET_DHT_Handle *dht_handle;
- /**
- * Handle to perform DNS lookups.
- */
- static struct GNUNET_DNSSTUB_Context *dns_handle;
- /**
- * Heap for limiting parallel DHT lookups
- */
- static struct GNUNET_CONTAINER_Heap *dht_lookup_heap;
- /**
- * Maximum amount of parallel queries to the DHT
- */
- static unsigned long long max_allowed_background_queries;
- /**
- * Head of resolver lookup list
- */
- static struct GNS_ResolverHandle *rlh_head;
- /**
- * Tail of resolver lookup list
- */
- static struct GNS_ResolverHandle *rlh_tail;
- /**
- * Organized in a DLL.
- */
- static struct CacheOps *co_head;
- /**
- * Organized in a DLL.
- */
- static struct CacheOps *co_tail;
- /**
- * Use namecache
- */
- static int use_cache;
- /**
- * Global configuration.
- */
- static const struct GNUNET_CONFIGURATION_Handle *cfg;
- /**
- * Determine if this name is canonical (is a legal name in a zone, without delegation);
- * note that we do not test that the name does not contain illegal characters, we only
- * test for delegation. Note that service records (i.e. _foo._srv) are canonical names
- * even though they consist of multiple labels.
- *
- * Examples:
- * a.b.gnu = not canonical
- * a = canonical
- * _foo._srv = canonical
- * _f.bar = not canonical
- *
- * @param name the name to test
- * @return #GNUNET_YES if canonical
- */
- static int
- is_canonical (const char *name)
- {
- const char *pos;
- const char *dot;
- if (NULL == strchr (name, '.'))
- return GNUNET_YES;
- if ('_' != name[0])
- return GNUNET_NO;
- pos = &name[1];
- while (NULL != (dot = strchr (pos, '.')))
- if ('_' != dot[1])
- return GNUNET_NO;
- else
- pos = dot + 1;
- return GNUNET_YES;
- }
- /* ************************** Resolution **************************** */
- /**
- * Expands a name ending in .+ with the zone of origin.
- *
- * @param rh resolution context
- * @param name name to modify (to be free'd or returned)
- * @return updated name
- */
- static char *
- translate_dot_plus (struct GNS_ResolverHandle *rh,
- char *name)
- {
- char *ret;
- size_t s_len = strlen (name);
- if (0 != strcmp (&name[s_len - 2],
- ".+"))
- return name; /* did not end in ".+" */
- GNUNET_assert (GNUNET_YES == rh->ac_tail->gns_authority);
- GNUNET_asprintf (&ret,
- "%.*s.%s",
- (int) (s_len - 2),
- name,
- GNUNET_GNSRECORD_pkey_to_zkey (&rh->ac_tail->authority_info.gns_authority));
- GNUNET_free (name);
- return ret;
- }
- /**
- * Task scheduled to asynchronously fail a resolution.
- *
- * @param cls the 'struct GNS_ResolverHandle' of the resolution to fail
- * @param tc task context
- */
- static void
- fail_resolution (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
- {
- struct GNS_ResolverHandle *rh = cls;
- rh->task_id = GNUNET_SCHEDULER_NO_TASK;
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- }
- #if (defined WINDOWS) || (defined DARWIN)
- /* Don't have this on W32, here's a naive implementation
- * Was somehow removed on OS X ... */
- static void *
- memrchr (const void *s,
- int c,
- size_t n)
- {
- const unsigned char *ucs = s;
- ssize_t i;
- for (i = n - 1; i >= 0; i--)
- if (c == (int) ucs[i])
- return (void *) &ucs[i];
- return NULL;
- }
- #endif
- /**
- * Get the next, rightmost label from the name that we are trying to resolve,
- * and update the resolution position accordingly. Labels usually consist
- * of up to 63 characters without a period ("."); however, we use a special
- * convention to support SRV and TLSA records where the domain name
- * includes an encoding for a service and protocol in the name. The
- * syntax (see RFC 2782) here is "_Service._Proto.Name" and in this
- * special case we include the "_Service._Proto" in the rightmost label.
- * Thus, for "_443._tcp.foo.bar" we first return the label "bar" and then
- * the label "_443._tcp.foo". The special case is detected by the
- * presence of labels beginning with an underscore. Whenever a label
- * begins with an underscore, it is combined with the label to its right
- * (and the "." is preserved).
- *
- * @param rh handle to the resolution operation to get the next label from
- * @return NULL if there are no more labels
- */
- static char *
- resolver_lookup_get_next_label (struct GNS_ResolverHandle *rh)
- {
- const char *rp;
- const char *dot;
- size_t len;
- char *ret;
- char *srv_name;
- char *proto_name;
- struct protoent *pe;
- struct servent *se;
- if (0 == rh->name_resolution_pos)
- return NULL;
- dot = memrchr (rh->name,
- (int) '.',
- rh->name_resolution_pos);
- if (NULL == dot)
- {
- /* done, this was the last one */
- len = rh->name_resolution_pos;
- rp = rh->name;
- rh->name_resolution_pos = 0;
- }
- else
- {
- /* advance by one label */
- len = rh->name_resolution_pos - (dot - rh->name) - 1;
- rp = dot + 1;
- rh->name_resolution_pos = dot - rh->name;
- }
- rh->protocol = 0;
- rh->service = 0;
- ret = GNUNET_strndup (rp, len);
- /* If we have labels starting with underscore with label on
- * the right (SRV/DANE/BOX case), determine port/protocol;
- * The format of `rh->name` must be "_PORT._PROTOCOL".
- */
- if ( ('_' == rh->name[0]) &&
- (NULL != (dot = memrchr (rh->name,
- (int) '.',
- rh->name_resolution_pos))) &&
- ('_' == dot[1]) &&
- (NULL == memrchr (rh->name,
- (int) '.',
- dot - rh->name)) )
- {
- srv_name = GNUNET_strndup (&rh->name[1],
- (dot - rh->name) - 1);
- proto_name = GNUNET_strndup (&dot[2],
- rh->name_resolution_pos - (dot - rh->name) - 1);
- rh->name_resolution_pos = 0;
- pe = getprotobyname (proto_name);
- if (NULL == pe)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Protocol `%s' unknown, skipping labels.\n"),
- proto_name);
- GNUNET_free (proto_name);
- GNUNET_free (srv_name);
- return ret;
- }
- se = getservbyname (srv_name,
- proto_name);
- if (NULL == se)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Service `%s' unknown for protocol `%s', skipping labels.\n"),
- srv_name,
- proto_name);
- GNUNET_free (proto_name);
- GNUNET_free (srv_name);
- return ret;
- }
- rh->protocol = pe->p_proto;
- rh->service = se->s_port;
- }
- return ret;
- }
- /**
- * Gives the cummulative result obtained to the callback and clean up the request.
- *
- * @param rh resolution process that has culminated in a result
- */
- static void
- transmit_lookup_dns_result (struct GNS_ResolverHandle *rh)
- {
- struct DnsResult *pos;
- unsigned int n;
- unsigned int i;
- n = 0;
- for (pos = rh->dns_result_head; NULL != pos; pos = pos->next)
- n++;
- {
- struct GNUNET_GNSRECORD_Data rd[n];
- i = 0;
- for (pos = rh->dns_result_head; NULL != pos; pos = pos->next)
- {
- rd[i].data = pos->data;
- rd[i].data_size = pos->data_size;
- rd[i].record_type = pos->record_type;
- if (0 == pos->expiration_time)
- {
- rd[i].flags = GNUNET_GNSRECORD_RF_RELATIVE_EXPIRATION;
- rd[i].expiration_time = 0;
- }
- else
- {
- rd[i].flags = GNUNET_GNSRECORD_RF_NONE;
- rd[i].expiration_time = pos->expiration_time;
- }
- i++;
- }
- GNUNET_assert (i == n);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Transmitting standard DNS result with %u records\n",
- n);
- rh->proc (rh->proc_cls,
- n,
- rd);
- }
- GNS_resolver_lookup_cancel (rh);
- }
- /**
- * Add a result from DNS to the records to be returned to the application.
- *
- * @param rh resolution request to extend with a result
- * @param expiration_time expiration time for the answer
- * @param record_type DNS record type of the answer
- * @param data_size number of bytes in @a data
- * @param data binary data to return in DNS record
- */
- static void
- add_dns_result (struct GNS_ResolverHandle *rh,
- uint64_t expiration_time,
- uint32_t record_type,
- size_t data_size,
- const void *data)
- {
- struct DnsResult *res;
- res = GNUNET_malloc (sizeof (struct DnsResult) + data_size);
- res->expiration_time = expiration_time;
- res->data_size = data_size;
- res->record_type = record_type;
- res->data = &res[1];
- memcpy (&res[1], data, data_size);
- GNUNET_CONTAINER_DLL_insert (rh->dns_result_head,
- rh->dns_result_tail,
- res);
- }
- /**
- * We had to do a DNS lookup. Convert the result (if any) and return
- * it.
- *
- * @param cls closure with the `struct GNS_ResolverHandle`
- * @param addr one of the addresses of the host, NULL for the last address
- * @param addrlen length of the address
- */
- static void
- handle_dns_result (void *cls,
- const struct sockaddr *addr,
- socklen_t addrlen)
- {
- struct GNS_ResolverHandle *rh = cls;
- const struct sockaddr_in *sa4;
- const struct sockaddr_in6 *sa6;
- if (NULL == addr)
- {
- rh->std_resolve = NULL;
- transmit_lookup_dns_result (rh);
- return;
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received %u bytes of DNS IP data\n",
- addrlen);
- switch (addr->sa_family)
- {
- case AF_INET:
- sa4 = (const struct sockaddr_in *) addr;
- add_dns_result (rh,
- 0 /* expiration time is unknown */,
- GNUNET_DNSPARSER_TYPE_A,
- sizeof (struct in_addr),
- &sa4->sin_addr);
- break;
- case AF_INET6:
- sa6 = (const struct sockaddr_in6 *) addr;
- add_dns_result (rh,
- 0 /* expiration time is unknown */,
- GNUNET_DNSPARSER_TYPE_AAAA,
- sizeof (struct in6_addr),
- &sa6->sin6_addr);
- break;
- default:
- GNUNET_break (0);
- break;
- }
- }
- /**
- * Task scheduled to continue with the resolution process.
- *
- * @param cls the 'struct GNS_ResolverHandle' of the resolution
- * @param tc task context
- */
- static void
- recursive_resolution (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc);
- /**
- * Begin the resolution process from 'name', starting with
- * the identification of the zone specified by 'name'.
- *
- * @param rh resolution to perform
- */
- static void
- start_resolver_lookup (struct GNS_ResolverHandle *rh);
- /**
- * Function called with the result of a DNS resolution.
- *
- * @param cls the request handle of the resolution that
- * we were attempting to make
- * @param rs socket that received the response
- * @param dns dns response, never NULL
- * @param dns_len number of bytes in @a dns
- */
- static void
- dns_result_parser (void *cls,
- struct GNUNET_DNSSTUB_RequestSocket *rs,
- const struct GNUNET_TUN_DnsHeader *dns,
- size_t dns_len)
- {
- struct GNS_ResolverHandle *rh = cls;
- struct GNUNET_DNSPARSER_Packet *p;
- const struct GNUNET_DNSPARSER_Record *rec;
- unsigned int rd_count;
- unsigned int i;
- rh->dns_request = NULL;
- GNUNET_SCHEDULER_cancel (rh->task_id);
- rh->task_id = GNUNET_SCHEDULER_NO_TASK;
- p = GNUNET_DNSPARSER_parse ((const char *) dns,
- dns_len);
- if (NULL == p)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Failed to parse DNS response\n"));
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received DNS response for `%s' with %u answers\n",
- rh->ac_tail->label,
- (unsigned int) p->num_answers);
- if ( (p->num_answers > 0) &&
- (GNUNET_DNSPARSER_TYPE_CNAME == p->answers[0].type) &&
- (GNUNET_DNSPARSER_TYPE_CNAME != rh->record_type) )
- {
- GNUNET_free (rh->name);
- rh->name = GNUNET_strdup (p->answers[0].data.hostname);
- rh->name_resolution_pos = strlen (rh->name);
- start_resolver_lookup (rh);
- GNUNET_DNSPARSER_free_packet (p);
- return;
- }
- /* convert from (parsed) DNS to (binary) GNS format! */
- rd_count = p->num_answers + p->num_authority_records + p->num_additional_records;
- {
- struct GNUNET_GNSRECORD_Data rd[rd_count];
- unsigned int skip;
- char buf[UINT16_MAX];
- size_t buf_off;
- size_t buf_start;
- buf_off = 0;
- skip = 0;
- memset (rd, 0, sizeof (rd));
- for (i=0;i<rd_count;i++)
- {
- if (i < p->num_answers)
- rec = &p->answers[i];
- else if (i < p->num_answers + p->num_authority_records)
- rec = &p->authority_records[i - p->num_answers];
- else
- rec = &p->authority_records[i - p->num_answers - p->num_authority_records];
- /* As we copied the full DNS name to 'rh->ac_tail->label', this
- should be the correct check to see if this record is actually
- a record for our label... */
- if (0 != strcmp (rec->name,
- rh->ac_tail->label))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Dropping record `%s', does not match desired name `%s'\n",
- rec->name,
- rh->ac_tail->label);
- skip++;
- continue;
- }
- rd[i - skip].record_type = rec->type;
- rd[i - skip].expiration_time = rec->expiration_time.abs_value_us;
- switch (rec->type)
- {
- case GNUNET_DNSPARSER_TYPE_A:
- if (rec->data.raw.data_len != sizeof (struct in_addr))
- {
- GNUNET_break_op (0);
- skip++;
- continue;
- }
- rd[i - skip].data_size = rec->data.raw.data_len;
- rd[i - skip].data = rec->data.raw.data;
- break;
- case GNUNET_DNSPARSER_TYPE_AAAA:
- if (rec->data.raw.data_len != sizeof (struct in6_addr))
- {
- GNUNET_break_op (0);
- skip++;
- continue;
- }
- rd[i - skip].data_size = rec->data.raw.data_len;
- rd[i - skip].data = rec->data.raw.data;
- break;
- case GNUNET_DNSPARSER_TYPE_CNAME:
- case GNUNET_DNSPARSER_TYPE_PTR:
- case GNUNET_DNSPARSER_TYPE_NS:
- buf_start = buf_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_name (buf,
- sizeof (buf),
- &buf_off,
- rec->data.hostname))
- {
- GNUNET_break (0);
- skip++;
- continue;
- }
- rd[i - skip].data_size = buf_off - buf_start;
- rd[i - skip].data = &buf[buf_start];
- break;
- case GNUNET_DNSPARSER_TYPE_SOA:
- buf_start = buf_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_soa (buf,
- sizeof (buf),
- &buf_off,
- rec->data.soa))
- {
- GNUNET_break (0);
- skip++;
- continue;
- }
- rd[i - skip].data_size = buf_off - buf_start;
- rd[i - skip].data = &buf[buf_start];
- break;
- case GNUNET_DNSPARSER_TYPE_MX:
- buf_start = buf_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_mx (buf,
- sizeof (buf),
- &buf_off,
- rec->data.mx))
- {
- GNUNET_break (0);
- skip++;
- continue;
- }
- rd[i - skip].data_size = buf_off - buf_start;
- rd[i - skip].data = &buf[buf_start];
- break;
- case GNUNET_DNSPARSER_TYPE_SRV:
- buf_start = buf_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_srv (buf,
- sizeof (buf),
- &buf_off,
- rec->data.srv))
- {
- GNUNET_break (0);
- skip++;
- continue;
- }
- rd[i - skip].data_size = buf_off - buf_start;
- rd[i - skip].data = &buf[buf_start];
- break;
- default:
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("Skipping record of unsupported type %d\n"),
- rec->type);
- skip++;
- continue;
- }
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Returning DNS response for `%s' with %u answers\n",
- rh->ac_tail->label,
- (unsigned int) p->num_answers);
- rh->proc (rh->proc_cls, rd_count - skip, rd);
- GNS_resolver_lookup_cancel (rh);
- }
- GNUNET_DNSPARSER_free_packet (p);
- }
- /**
- * Perform recursive DNS resolution. Asks the given DNS resolver to
- * resolve "rh->dns_name", possibly recursively proceeding following
- * NS delegations, CNAMES, etc., until 'rh->loop_limiter' bounds us or
- * we find the answer.
- *
- * @param rh resolution information
- */
- static void
- recursive_dns_resolution (struct GNS_ResolverHandle *rh)
- {
- struct AuthorityChain *ac;
- socklen_t sa_len;
- struct GNUNET_DNSPARSER_Query *query;
- struct GNUNET_DNSPARSER_Packet *p;
- char *dns_request;
- size_t dns_request_length;
- ac = rh->ac_tail;
- GNUNET_assert (NULL != ac);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Starting DNS lookup for `%s'\n",
- ac->label);
- GNUNET_assert (GNUNET_NO == ac->gns_authority);
- switch (((const struct sockaddr *) &ac->authority_info.dns_authority.dns_ip)->sa_family)
- {
- case AF_INET:
- sa_len = sizeof (struct sockaddr_in);
- break;
- case AF_INET6:
- sa_len = sizeof (struct sockaddr_in6);
- break;
- default:
- GNUNET_break (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- query = GNUNET_new (struct GNUNET_DNSPARSER_Query);
- query->name = GNUNET_strdup (ac->label);
- query->type = rh->record_type;
- query->dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET;
- p = GNUNET_new (struct GNUNET_DNSPARSER_Packet);
- p->queries = query;
- p->num_queries = 1;
- p->id = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
- UINT16_MAX);
- p->flags.opcode = GNUNET_TUN_DNS_OPCODE_QUERY;
- p->flags.recursion_desired = 1;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_pack (p, 1024, &dns_request, &dns_request_length))
- {
- GNUNET_break (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- }
- else
- {
- rh->dns_request = GNUNET_DNSSTUB_resolve (dns_handle,
- (const struct sockaddr *) &ac->authority_info.dns_authority.dns_ip,
- sa_len,
- dns_request,
- dns_request_length,
- &dns_result_parser,
- rh);
- rh->task_id = GNUNET_SCHEDULER_add_delayed (DNS_LOOKUP_TIMEOUT,
- &fail_resolution,
- rh);
- }
- GNUNET_free (dns_request);
- GNUNET_DNSPARSER_free_packet (p);
- }
- /**
- * We encountered a CNAME record during our resolution.
- * Merge it into our chain.
- *
- * @param rh resolution we are performing
- * @param cname value of the cname record we got for the current
- * authority chain tail
- */
- static void
- handle_gns_cname_result (struct GNS_ResolverHandle *rh,
- const char *cname)
- {
- size_t nlen;
- char *res;
- struct AuthorityChain *ac;
- nlen = strlen (cname);
- if ( (nlen > 2) &&
- (0 == strcmp (".+",
- &cname[nlen - 2])) )
- {
- /* CNAME resolution continues relative to current domain */
- if (0 == rh->name_resolution_pos)
- {
- res = GNUNET_strndup (cname, nlen - 2);
- rh->name_resolution_pos = nlen - 2;
- }
- else
- {
- GNUNET_asprintf (&res,
- "%.*s.%.*s",
- (int) rh->name_resolution_pos,
- rh->name,
- (int) (nlen - 2),
- cname);
- rh->name_resolution_pos = strlen (res);
- }
- GNUNET_free (rh->name);
- rh->name = res;
- ac = GNUNET_new (struct AuthorityChain);
- ac->rh = rh;
- ac->gns_authority = GNUNET_YES;
- ac->authority_info.gns_authority = rh->ac_tail->authority_info.gns_authority;
- ac->label = resolver_lookup_get_next_label (rh);
- ac->suggested_shortening_label = NULL;
- ac->shortening_started = GNUNET_NO;
- /* add AC to tail */
- GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
- rh->ac_tail,
- ac);
- rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
- rh);
- return;
- }
- /* name is absolute, start from the beginning */
- GNUNET_free (rh->name);
- rh->name = GNUNET_strdup (cname);
- rh->name_resolution_pos = strlen (rh->name);
- start_resolver_lookup (rh);
- }
- /**
- * Process a records that were decrypted from a block.
- *
- * @param cls closure with the 'struct GNS_ResolverHandle'
- * @param rd_count number of entries in @a rd array
- * @param rd array of records with data to store
- */
- static void
- handle_gns_resolution_result (void *cls,
- unsigned int rd_count,
- const struct GNUNET_GNSRECORD_Data *rd);
- /**
- * Callback invoked from the VPN service once a redirection is
- * available. Provides the IP address that can now be used to
- * reach the requested destination. Replaces the "VPN" record
- * with the respective A/AAAA record and continues processing.
- *
- * @param cls closure
- * @param af address family, AF_INET or AF_INET6; AF_UNSPEC on error;
- * will match 'result_af' from the request
- * @param address IP address (struct in_addr or struct in_addr6, depending on 'af')
- * that the VPN allocated for the redirection;
- * traffic to this IP will now be redirected to the
- * specified target peer; NULL on error
- */
- static void
- vpn_allocation_cb (void *cls,
- int af,
- const void *address)
- {
- struct VpnContext *vpn_ctx = cls;
- struct GNS_ResolverHandle *rh = vpn_ctx->rh;
- struct GNUNET_GNSRECORD_Data rd[vpn_ctx->rd_count];
- unsigned int i;
- vpn_ctx->vpn_request = NULL;
- rh->vpn_ctx = NULL;
- GNUNET_assert (GNUNET_OK ==
- GNUNET_GNSRECORD_records_deserialize (vpn_ctx->rd_data_size,
- vpn_ctx->rd_data,
- vpn_ctx->rd_count,
- rd));
- for (i=0;i<vpn_ctx->rd_count;i++)
- {
- if (GNUNET_GNSRECORD_TYPE_VPN == rd[i].record_type)
- {
- switch (af)
- {
- case AF_INET:
- rd[i].record_type = GNUNET_DNSPARSER_TYPE_A;
- rd[i].data_size = sizeof (struct in_addr);
- rd[i].expiration_time = GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT).abs_value_us;
- rd[i].flags = 0;
- rd[i].data = address;
- break;
- case AF_INET6:
- rd[i].record_type = GNUNET_DNSPARSER_TYPE_AAAA;
- rd[i].expiration_time = GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT).abs_value_us;
- rd[i].flags = 0;
- rd[i].data = address;
- rd[i].data_size = sizeof (struct in6_addr);
- break;
- default:
- GNUNET_assert (0);
- }
- break;
- }
- }
- GNUNET_assert (i < vpn_ctx->rd_count);
- handle_gns_resolution_result (rh,
- vpn_ctx->rd_count,
- rd);
- GNUNET_free (vpn_ctx->rd_data);
- GNUNET_free (vpn_ctx);
- }
- /**
- * We've resolved the IP address for the DNS resolver to use
- * after encountering a GNS2DNS record.
- *
- * TODO: Right now we only foward the request to ONE DNS resolver,
- * even if we get multiple IP addresses back; a correct implementation
- * should try all DNS resolvers.
- *
- * @param cls the `struct GNS_ResolverHandle` where we encountered
- * the GNS2DNS record
- * @param rd_count number of records in @a rd
- * @param rd addresses for the DNS resolver (presumably)
- */
- static void
- handle_gns2dns_result (void *cls,
- unsigned int rd_count,
- const struct GNUNET_GNSRECORD_Data *rd)
- {
- struct GNS_ResolverHandle *rh = cls;
- struct AuthorityChain *ac;
- unsigned int j;
- struct sockaddr *sa;
- struct sockaddr_in v4;
- struct sockaddr_in6 v6;
- size_t sa_len;
- /* find suitable A/AAAA record */
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received %u results for IP address of DNS server for GNS2DNS transition\n",
- rd_count);
- /* enable cleanup of 'rh' handle that comes next... */
- GNUNET_CONTAINER_DLL_insert (rlh_head,
- rlh_tail,
- rh->g2dc->rh);
- rh->g2dc->rh = NULL;
- sa = NULL;
- sa_len = 0;
- for (j=0;j<rd_count;j++)
- {
- switch (rd[j].record_type)
- {
- case GNUNET_DNSPARSER_TYPE_A:
- if (sizeof (struct in_addr) != rd[j].data_size)
- {
- GNUNET_break_op (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- /* FIXME: might want to check if we support IPv4 here,
- and otherwise skip this one and hope we find another */
- memset (&v4, 0, sizeof (v4));
- sa_len = sizeof (v4);
- v4.sin_family = AF_INET;
- v4.sin_port = htons (53);
- #if HAVE_SOCKADDR_IN_SIN_LEN
- v4.sin_len = (u_char) sa_len;
- #endif
- memcpy (&v4.sin_addr,
- rd[j].data,
- sizeof (struct in_addr));
- sa = (struct sockaddr *) &v4;
- break;
- case GNUNET_DNSPARSER_TYPE_AAAA:
- if (sizeof (struct in6_addr) != rd[j].data_size)
- {
- GNUNET_break_op (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- /* FIXME: might want to check if we support IPv6 here,
- and otherwise skip this one and hope we find another */
- memset (&v6, 0, sizeof (v6));
- sa_len = sizeof (v6);
- v6.sin6_family = AF_INET6;
- v6.sin6_port = htons (53);
- #if HAVE_SOCKADDR_IN_SIN_LEN
- v6.sin6_len = (u_char) sa_len;
- #endif
- memcpy (&v6.sin6_addr,
- rd[j].data,
- sizeof (struct in6_addr));
- sa = (struct sockaddr *) &v6;
- break;
- default:
- break;
- }
- if (NULL != sa)
- break;
- }
- if (NULL == sa)
- {
- /* we cannot continue; NS without A/AAAA */
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- /* expand authority chain */
- ac = GNUNET_new (struct AuthorityChain);
- ac->rh = rh;
- strcpy (ac->authority_info.dns_authority.name,
- rh->g2dc->ns);
- memcpy (&ac->authority_info.dns_authority.dns_ip,
- sa,
- sa_len);
- /* for DNS recursion, the label is the full DNS name,
- created from the remainder of the GNS name and the
- name in the NS record */
- GNUNET_asprintf (&ac->label,
- "%.*s%s%s",
- (int) rh->name_resolution_pos,
- rh->name,
- (0 != rh->name_resolution_pos) ? "." : "",
- rh->g2dc->ns);
- GNUNET_free (rh->g2dc->ns);
- GNUNET_free (rh->g2dc);
- rh->g2dc = NULL;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Will continue resolution using DNS server `%s' to resolve `%s'\n",
- GNUNET_a2s (sa, sa_len),
- ac->label);
- GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
- rh->ac_tail,
- ac);
- if (strlen (ac->label) > GNUNET_DNSPARSER_MAX_NAME_LENGTH)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("GNS lookup resulted in DNS name that is too long (`%s')\n"),
- ac->label);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- /* recurse */
- rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
- rh);
- }
- /**
- * Process a records that were decrypted from a block.
- *
- * @param cls closure with the `struct GNS_ResolverHandle`
- * @param rd_count number of entries in @a rd array
- * @param rd array of records with data to store
- */
- static void
- handle_gns_resolution_result (void *cls,
- unsigned int rd_count,
- const struct GNUNET_GNSRECORD_Data *rd)
- {
- struct GNS_ResolverHandle *rh = cls;
- struct AuthorityChain *ac;
- struct AuthorityChain *shorten_ac;
- unsigned int i;
- char *cname;
- struct VpnContext *vpn_ctx;
- const struct GNUNET_TUN_GnsVpnRecord *vpn;
- const char *vname;
- struct GNUNET_HashCode vhash;
- int af;
- char scratch[UINT16_MAX];
- size_t scratch_off;
- size_t scratch_start;
- size_t off;
- struct GNUNET_GNSRECORD_Data rd_new[rd_count];
- unsigned int rd_off;
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- "Resolution succeeded for `%s' in zone %s, got %u records\n",
- rh->ac_tail->label,
- GNUNET_GNSRECORD_z2s (&rh->ac_tail->authority_info.gns_authority),
- rd_count);
- if (0 == rh->name_resolution_pos)
- {
- /* top-level match, are we done yet? */
- if ( (rd_count > 0) &&
- (GNUNET_DNSPARSER_TYPE_CNAME == rd[0].record_type) &&
- (GNUNET_DNSPARSER_TYPE_CNAME != rh->record_type) )
- {
- off = 0;
- cname = GNUNET_DNSPARSER_parse_name (rd[0].data,
- rd[0].data_size,
- &off);
- if ( (NULL == cname) ||
- (off != rd[0].data_size) )
- {
- GNUNET_break_op (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- GNUNET_free_non_null (cname);
- return;
- }
- handle_gns_cname_result (rh,
- cname);
- GNUNET_free (cname);
- return;
- }
- /* If A/AAAA was requested, but we got a VPN
- record, we convert it to A/AAAA using GNUnet VPN */
- if ( (GNUNET_DNSPARSER_TYPE_A == rh->record_type) ||
- (GNUNET_DNSPARSER_TYPE_AAAA == rh->record_type) )
- {
- for (i=0;i<rd_count;i++)
- {
- switch (rd[i].record_type)
- {
- case GNUNET_GNSRECORD_TYPE_VPN:
- {
- af = (GNUNET_DNSPARSER_TYPE_A == rh->record_type) ? AF_INET : AF_INET6;
- if (sizeof (struct GNUNET_TUN_GnsVpnRecord) >
- rd[i].data_size)
- {
- GNUNET_break_op (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- vpn = (const struct GNUNET_TUN_GnsVpnRecord *) rd[i].data;
- vname = (const char *) &vpn[1];
- if ('\0' != vname[rd[i].data_size - 1 - sizeof (struct GNUNET_TUN_GnsVpnRecord)])
- {
- GNUNET_break_op (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- GNUNET_TUN_service_name_to_hash (vname,
- &vhash);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Attempting VPN allocation for %s-%s (AF: %d, proto %d)\n",
- GNUNET_i2s (&vpn->peer),
- vname,
- (int) af,
- (int) ntohs (vpn->proto));
- vpn_ctx = GNUNET_new (struct VpnContext);
- rh->vpn_ctx = vpn_ctx;
- vpn_ctx->rh = rh;
- vpn_ctx->rd_data_size = GNUNET_GNSRECORD_records_get_size (rd_count,
- rd);
- vpn_ctx->rd_data = GNUNET_malloc (vpn_ctx->rd_data_size);
- vpn_ctx->rd_count = rd_count;
- GNUNET_assert (vpn_ctx->rd_data_size ==
- GNUNET_GNSRECORD_records_serialize (rd_count,
- rd,
- vpn_ctx->rd_data_size,
- vpn_ctx->rd_data));
- vpn_ctx->vpn_request = GNUNET_VPN_redirect_to_peer (vpn_handle,
- af,
- ntohs (vpn->proto),
- &vpn->peer,
- &vhash,
- GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT),
- &vpn_allocation_cb,
- vpn_ctx);
- return;
- }
- case GNUNET_GNSRECORD_TYPE_GNS2DNS:
- {
- /* delegation to DNS */
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Found GNS2DNS record, delegating to DNS!\n");
- goto do_recurse;
- }
- default:
- break;
- } /* end: switch */
- } /* end: for rd */
- } /* end: name_resolution_pos */
- /* convert relative names in record values to absolute names,
- using 'scratch' array for memory allocations */
- scratch_off = 0;
- rd_off = 0;
- shorten_ac = rh->ac_tail;
- for (i=0;i<rd_count;i++)
- {
- if ( (0 != rh->protocol) &&
- (0 != rh->service) &&
- (GNUNET_GNSRECORD_TYPE_BOX != rd[i].record_type) )
- continue; /* we _only_ care about boxed records */
- rd_new[rd_off] = rd[i];
- /* Check if the embedded name(s) end in "+", and if so,
- replace the "+" with the zone at "ac_tail", changing the name
- to a ".zkey". The name is allocated on the 'scratch' array,
- so we can free it afterwards. */
- switch (rd[i].record_type)
- {
- case GNUNET_DNSPARSER_TYPE_CNAME:
- {
- char *cname;
- off = 0;
- cname = GNUNET_DNSPARSER_parse_name (rd[i].data,
- rd[i].data_size,
- &off);
- if ( (NULL == cname) ||
- (off != rd[i].data_size) )
- {
- GNUNET_break_op (0); /* record not well-formed */
- }
- else
- {
- cname = translate_dot_plus (rh, cname);
- GNUNET_break (NULL != cname);
- scratch_start = scratch_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_name (scratch,
- sizeof (scratch),
- &scratch_off,
- cname))
- {
- GNUNET_break (0);
- }
- else
- {
- rd_new[rd_off].data = &scratch[scratch_start];
- rd_new[rd_off].data_size = scratch_off - scratch_start;
- rd_off++;
- }
- }
- GNUNET_free_non_null (cname);
- }
- break;
- case GNUNET_DNSPARSER_TYPE_SOA:
- {
- struct GNUNET_DNSPARSER_SoaRecord *soa;
- off = 0;
- soa = GNUNET_DNSPARSER_parse_soa (rd[i].data,
- rd[i].data_size,
- &off);
- if ( (NULL == soa) ||
- (off != rd[i].data_size) )
- {
- GNUNET_break_op (0); /* record not well-formed */
- }
- else
- {
- soa->mname = translate_dot_plus (rh, soa->mname);
- soa->rname = translate_dot_plus (rh, soa->rname);
- scratch_start = scratch_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_soa (scratch,
- sizeof (scratch),
- &scratch_off,
- soa))
- {
- GNUNET_break (0);
- }
- else
- {
- rd_new[rd_off].data = &scratch[scratch_start];
- rd_new[rd_off].data_size = scratch_off - scratch_start;
- rd_off++;
- }
- }
- if (NULL != soa)
- GNUNET_DNSPARSER_free_soa (soa);
- }
- break;
- case GNUNET_DNSPARSER_TYPE_MX:
- {
- struct GNUNET_DNSPARSER_MxRecord *mx;
- off = 0;
- mx = GNUNET_DNSPARSER_parse_mx (rd[i].data,
- rd[i].data_size,
- &off);
- if ( (NULL == mx) ||
- (off != rd[i].data_size) )
- {
- GNUNET_break_op (0); /* record not well-formed */
- }
- else
- {
- mx->mxhost = translate_dot_plus (rh, mx->mxhost);
- scratch_start = scratch_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_mx (scratch,
- sizeof (scratch),
- &scratch_off,
- mx))
- {
- GNUNET_break (0);
- }
- else
- {
- rd_new[rd_off].data = &scratch[scratch_start];
- rd_new[rd_off].data_size = scratch_off - scratch_start;
- rd_off++;
- }
- }
- if (NULL != mx)
- GNUNET_DNSPARSER_free_mx (mx);
- }
- break;
- case GNUNET_DNSPARSER_TYPE_SRV:
- {
- struct GNUNET_DNSPARSER_SrvRecord *srv;
- off = 0;
- srv = GNUNET_DNSPARSER_parse_srv (rd[i].data,
- rd[i].data_size,
- &off);
- if ( (NULL == srv) ||
- (off != rd[i].data_size) )
- {
- GNUNET_break_op (0); /* record not well-formed */
- }
- else
- {
- srv->target = translate_dot_plus (rh, srv->target);
- scratch_start = scratch_off;
- if (GNUNET_OK !=
- GNUNET_DNSPARSER_builder_add_srv (scratch,
- sizeof (scratch),
- &scratch_off,
- srv))
- {
- GNUNET_break (0);
- }
- else
- {
- rd_new[rd_off].data = &scratch[scratch_start];
- rd_new[rd_off].data_size = scratch_off - scratch_start;
- rd_off++;
- }
- }
- if (NULL != srv)
- GNUNET_DNSPARSER_free_srv (srv);
- }
- break;
- case GNUNET_GNSRECORD_TYPE_NICK:
- {
- const char *nick;
- nick = rd[i].data;
- if ((rd[i].data_size > 0) &&
- (nick[rd[i].data_size -1] != '\0'))
- {
- GNUNET_break_op (0);
- break;
- }
- if (NULL == shorten_ac->suggested_shortening_label)
- shorten_ac->suggested_shortening_label = GNUNET_strdup (nick);
- break;
- }
- case GNUNET_GNSRECORD_TYPE_PKEY:
- {
- struct GNUNET_CRYPTO_EcdsaPublicKey pub;
- if (rd[i].data_size != sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey))
- {
- GNUNET_break_op (0);
- break;
- }
- memcpy (&pub, rd[i].data, rd[i].data_size);
- rd_off++;
- if (GNUNET_GNSRECORD_TYPE_PKEY != rh->record_type)
- {
- /* try to resolve "+" */
- struct AuthorityChain *ac;
- ac = GNUNET_new (struct AuthorityChain);
- ac->rh = rh;
- ac->gns_authority = GNUNET_YES;
- ac->authority_info.gns_authority = pub;
- ac->label = GNUNET_strdup (GNUNET_GNS_MASTERZONE_STR);
- ac->suggested_shortening_label = NULL;
- ac->shortening_started = GNUNET_NO;
- GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
- rh->ac_tail,
- ac);
- rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
- rh);
- return;
- }
- }
- break;
- case GNUNET_GNSRECORD_TYPE_GNS2DNS:
- {
- /* delegation to DNS */
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Found GNS2DNS record, delegating to DNS!\n");
- goto do_recurse;
- }
- case GNUNET_GNSRECORD_TYPE_BOX:
- {
- /* unbox SRV/TLSA records if a specific one was requested */
- if ( (0 != rh->protocol) &&
- (0 != rh->service) &&
- (rd[i].data_size >= sizeof (struct GNUNET_GNSRECORD_BoxRecord)) )
- {
- const struct GNUNET_GNSRECORD_BoxRecord *box;
- box = rd[i].data;
- if ( (ntohs (box->protocol) == rh->protocol) &&
- (ntohs (box->service) == rh->service) )
- {
- /* Box matches, unbox! */
- rd_new[rd_off].record_type = ntohl (box->record_type);
- rd_new[rd_off].data_size -= sizeof (struct GNUNET_GNSRECORD_BoxRecord);
- rd_new[rd_off].data = &box[1];
- rd_off++;
- }
- }
- else
- {
- /* no specific protocol/service specified, preserve all BOX
- records (for modern, GNS-enabled applications) */
- rd_off++;
- }
- }
- default:
- rd_off++;
- break;
- } /* end: switch */
- } /* end: for rd_count */
- /* trigger shortening */
- if ((NULL != rh->shorten_key) &&
- (NULL != shorten_ac) &&
- (GNUNET_NO == shorten_ac->shortening_started) &&
- (NULL != shorten_ac->suggested_shortening_label))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Start shortening for label `%s' based on nick `%s'\n",
- shorten_ac->label,
- shorten_ac->suggested_shortening_label);
- shorten_ac->shortening_started = GNUNET_YES;
- GNS_shorten_start (shorten_ac->label,
- shorten_ac->suggested_shortening_label,
- &shorten_ac->authority_info.gns_authority,
- rh->shorten_key);
- }
- /* yes, we are done, return result */
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Returning GNS response for `%s' with %u answers\n",
- rh->ac_tail->label,
- rd_off);
- rh->proc (rh->proc_cls, rd_off, rd_new);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- do_recurse:
- /* need to recurse, check if we can */
- for (i=0;i<rd_count;i++)
- {
- switch (rd[i].record_type)
- {
- case GNUNET_GNSRECORD_TYPE_PKEY:
- /* delegation to another zone */
- if (sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) !=
- rd[i].data_size)
- {
- GNUNET_break_op (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- /* expand authority chain */
- ac = GNUNET_new (struct AuthorityChain);
- ac->rh = rh;
- ac->gns_authority = GNUNET_YES;
- ac->suggested_shortening_label = NULL;
- ac->shortening_started = GNUNET_NO;
- memcpy (&ac->authority_info.gns_authority,
- rd[i].data,
- sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey));
- ac->label = resolver_lookup_get_next_label (rh);
- /* add AC to tail */
- GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
- rh->ac_tail,
- ac);
- /* recurse */
- rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
- rh);
- return;
- case GNUNET_GNSRECORD_TYPE_GNS2DNS:
- {
- /* resolution continues within DNS */
- struct Gns2DnsContext *g2dc;
- char *ip;
- char *ns;
- off = 0;
- ns = GNUNET_DNSPARSER_parse_name (rd[i].data,
- rd[i].data_size,
- &off);
- ip = GNUNET_DNSPARSER_parse_name (rd[i].data,
- rd[i].data_size,
- &off);
- if ( (NULL == ns) ||
- (NULL == ip) ||
- (off != rd[i].data_size) )
- {
- GNUNET_break_op (0);
- GNUNET_free_non_null (ns);
- GNUNET_free_non_null (ip);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Resolving `%s' to determine IP address of DNS server for GNS2DNS transition\n",
- ip);
- /* resolve 'ip' to determine the IP(s) of the DNS
- resolver to use */
- g2dc = GNUNET_new (struct Gns2DnsContext);
- g2dc->ns = ns;
- g2dc->rh = GNUNET_new (struct GNS_ResolverHandle);
- g2dc->rh->authority_zone = rh->ac_tail->authority_info.gns_authority;
- ip = translate_dot_plus (rh, ip);
- g2dc->rh->name = ip;
- g2dc->rh->name_resolution_pos = strlen (ip);
- g2dc->rh->proc = &handle_gns2dns_result;
- g2dc->rh->proc_cls = rh;
- g2dc->rh->record_type = GNUNET_GNSRECORD_TYPE_ANY;
- g2dc->rh->options = GNUNET_GNS_LO_DEFAULT;
- g2dc->rh->loop_limiter = rh->loop_limiter + 1;
- rh->g2dc = g2dc;
- start_resolver_lookup (g2dc->rh);
- return;
- }
- case GNUNET_DNSPARSER_TYPE_CNAME:
- {
- char *cname;
- off = 0;
- cname = GNUNET_DNSPARSER_parse_name (rd[i].data,
- rd[i].data_size,
- &off);
- if ( (NULL == cname) ||
- (off != rd[i].data_size) )
- {
- GNUNET_break_op (0); /* record not well-formed */
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- GNUNET_free_non_null (cname);
- return;
- }
- handle_gns_cname_result (rh,
- cname);
- GNUNET_free (cname);
- return;
- }
- /* FIXME: handle DNAME */
- default:
- /* skip */
- break;
- }
- }
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("GNS lookup recursion failed (no delegation record found)\n"));
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- }
- /**
- * Function called once the namestore has completed the request for
- * caching a block.
- *
- * @param cls closure with the `struct CacheOps`
- * @param success #GNUNET_OK on success
- * @param emsg error message
- */
- static void
- namecache_cache_continuation (void *cls,
- int32_t success,
- const char *emsg)
- {
- struct CacheOps *co = cls;
- co->namecache_qe_cache = NULL;
- if (NULL != emsg)
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Failed to cache GNS resolution: %s\n"),
- emsg);
- GNUNET_CONTAINER_DLL_remove (co_head,
- co_tail,
- co);
- GNUNET_free (co);
- }
- /**
- * Iterator called on each result obtained for a DHT
- * operation that expects a reply
- *
- * @param cls closure with the `struct GNS_ResolverHandle`
- * @param exp when will this value expire
- * @param key key of the result
- * @param get_path peers on reply path (or NULL if not recorded)
- * [0] = datastore's first neighbor, [length - 1] = local peer
- * @param get_path_length number of entries in @a get_path
- * @param put_path peers on the PUT path (or NULL if not recorded)
- * [0] = origin, [length - 1] = datastore
- * @param put_path_length number of entries in @a put_path
- * @param type type of the result
- * @param size number of bytes in data
- * @param data pointer to the result data
- */
- static void
- handle_dht_response (void *cls,
- struct GNUNET_TIME_Absolute exp,
- const struct 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 GNS_ResolverHandle *rh = cls;
- struct AuthorityChain *ac = rh->ac_tail;
- const struct GNUNET_GNSRECORD_Block *block;
- struct CacheOps *co;
- GNUNET_DHT_get_stop (rh->get_handle);
- rh->get_handle = NULL;
- GNUNET_CONTAINER_heap_remove_node (rh->dht_heap_node);
- rh->dht_heap_node = NULL;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Handling response from the DHT\n");
- if (size < sizeof (struct GNUNET_GNSRECORD_Block))
- {
- /* how did this pass DHT block validation!? */
- GNUNET_break (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- block = data;
- if (size !=
- ntohl (block->purpose.size) +
- sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) +
- sizeof (struct GNUNET_CRYPTO_EcdsaSignature))
- {
- /* how did this pass DHT block validation!? */
- GNUNET_break (0);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- if (GNUNET_OK !=
- GNUNET_GNSRECORD_block_decrypt (block,
- &ac->authority_info.gns_authority,
- ac->label,
- &handle_gns_resolution_result,
- rh))
- {
- GNUNET_break_op (0); /* block was ill-formed */
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- if (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (block->expiration_time)).rel_value_us)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received expired block from the DHT, will not cache it.\n");
- return;
- }
- /* Cache well-formed blocks */
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Caching response from the DHT in namecache\n");
- co = GNUNET_new (struct CacheOps);
- co->namecache_qe_cache = GNUNET_NAMECACHE_block_cache (namecache_handle,
- block,
- &namecache_cache_continuation,
- co);
- GNUNET_CONTAINER_DLL_insert (co_head,
- co_tail,
- co);
- }
- /**
- * Initiate a DHT query for a set of GNS records.
- *
- * @param rh resolution handle
- * @param query key to use in the DHT lookup
- */
- static void
- start_dht_request (struct GNS_ResolverHandle *rh,
- const struct GNUNET_HashCode *query)
- {
- struct GNS_ResolverHandle *rx;
- GNUNET_assert (NULL == rh->get_handle);
- rh->get_handle = GNUNET_DHT_get_start (dht_handle,
- GNUNET_BLOCK_TYPE_GNS_NAMERECORD,
- query,
- DHT_GNS_REPLICATION_LEVEL,
- GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
- NULL, 0,
- &handle_dht_response, rh);
- rh->dht_heap_node = GNUNET_CONTAINER_heap_insert (dht_lookup_heap,
- rh,
- GNUNET_TIME_absolute_get ().abs_value_us);
- if (GNUNET_CONTAINER_heap_get_size (dht_lookup_heap) > max_allowed_background_queries)
- {
- /* fail longest-standing DHT request */
- rx = GNUNET_CONTAINER_heap_peek (dht_lookup_heap);
- GNUNET_assert (NULL != rx);
- rx->proc (rx->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rx);
- }
- }
- /**
- * Process a records that were decrypted from a block that we got from
- * the namecache. Simply calls #handle_gns_resolution_result().
- *
- * @param cls closure with the `struct GNS_ResolverHandle`
- * @param rd_count number of entries in @a rd array
- * @param rd array of records with data to store
- */
- static void
- handle_gns_namecache_resolution_result (void *cls,
- unsigned int rd_count,
- const struct GNUNET_GNSRECORD_Data *rd)
- {
- struct GNS_ResolverHandle *rh = cls;
- handle_gns_resolution_result (rh,
- rd_count,
- rd);
- }
- /**
- * Process a record that was stored in the namecache.
- *
- * @param cls closure with the `struct GNS_ResolverHandle`
- * @param block block that was stored in the namecache
- */
- static void
- handle_namecache_block_response (void *cls,
- const struct GNUNET_GNSRECORD_Block *block)
- {
- struct GNS_ResolverHandle *rh = cls;
- struct AuthorityChain *ac = rh->ac_tail;
- const char *label = ac->label;
- const struct GNUNET_CRYPTO_EcdsaPublicKey *auth = &ac->authority_info.gns_authority;
- struct GNUNET_HashCode query;
- GNUNET_assert (NULL != rh->namecache_qe);
- rh->namecache_qe = NULL;
- if ( ( (GNUNET_GNS_LO_DEFAULT == rh->options) ||
- ( (GNUNET_GNS_LO_LOCAL_MASTER == rh->options) &&
- (ac != rh->ac_head) ) ) &&
- ( (NULL == block) ||
- (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (block->expiration_time)).rel_value_us) ) )
- {
- /* namecache knows nothing; try DHT lookup */
- GNUNET_GNSRECORD_query_from_public_key (auth,
- label,
- &query);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Starting DHT lookup for `%s' in zone `%s' under key `%s'\n",
- ac->label,
- GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority),
- GNUNET_h2s (&query));
- start_dht_request (rh, &query);
- return;
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Received result from namecache for label `%s'\n",
- ac->label);
- if ( (NULL == block) ||
- (0 == GNUNET_TIME_absolute_get_remaining (GNUNET_TIME_absolute_ntoh (block->expiration_time)).rel_value_us) )
- {
- /* DHT not permitted and no local result, fail */
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Resolution failed for `%s' in zone %s (DHT lookup not permitted by configuration)\n",
- ac->label,
- GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- if (GNUNET_OK !=
- GNUNET_GNSRECORD_block_decrypt (block,
- auth,
- label,
- &handle_gns_namecache_resolution_result,
- rh))
- {
- GNUNET_break_op (0); /* block was ill-formed */
- /* try DHT instead */
- GNUNET_GNSRECORD_query_from_public_key (auth,
- label,
- &query);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Starting DHT lookup for `%s' in zone `%s' under key `%s'\n",
- ac->label,
- GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority),
- GNUNET_h2s (&query));
- start_dht_request (rh, &query);
- return;
- }
- }
- /**
- * Lookup tail of our authority chain in the namecache.
- *
- * @param rh query we are processing
- */
- static void
- recursive_gns_resolution_namecache (struct GNS_ResolverHandle *rh)
- {
- struct AuthorityChain *ac = rh->ac_tail;
- struct GNUNET_HashCode query;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Starting GNS resolution for `%s' in zone %s\n",
- ac->label,
- GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
- GNUNET_GNSRECORD_query_from_public_key (&ac->authority_info.gns_authority,
- ac->label,
- &query);
- if (GNUNET_YES == use_cache)
- {
- rh->namecache_qe
- = GNUNET_NAMECACHE_lookup_block (namecache_handle,
- &query,
- &handle_namecache_block_response,
- rh);
- GNUNET_assert (NULL != rh->namecache_qe);
- }
- else
- {
- start_dht_request (rh, &query);
- }
- }
- /**
- * Function called with the result from a revocation check.
- *
- * @param cls the `struct GNS_ResovlerHandle`
- * @param is_valid #GNUNET_YES if the zone was not yet revoked
- */
- static void
- handle_revocation_result (void *cls,
- int is_valid)
- {
- struct GNS_ResolverHandle *rh = cls;
- struct AuthorityChain *ac = rh->ac_tail;
- rh->rev_check = NULL;
- if (GNUNET_YES != is_valid)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Zone %s was revoked, resolution fails\n"),
- GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- recursive_gns_resolution_namecache (rh);
- }
- /**
- * Perform revocation check on tail of our authority chain.
- *
- * @param rh query we are processing
- */
- static void
- recursive_gns_resolution_revocation (struct GNS_ResolverHandle *rh)
- {
- struct AuthorityChain *ac = rh->ac_tail;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Starting revocation check for zone %s\n",
- GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
- rh->rev_check = GNUNET_REVOCATION_query (cfg,
- &ac->authority_info.gns_authority,
- &handle_revocation_result,
- rh);
- GNUNET_assert (NULL != rh->rev_check);
- }
- /**
- * Task scheduled to continue with the resolution process.
- *
- * @param cls the `struct GNS_ResolverHandle` of the resolution
- * @param tc task context
- */
- static void
- recursive_resolution (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
- {
- struct GNS_ResolverHandle *rh = cls;
- rh->task_id = GNUNET_SCHEDULER_NO_TASK;
- if (MAX_RECURSION < rh->loop_limiter++)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- "Encountered unbounded recursion resolving `%s'\n",
- rh->name);
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- if (GNUNET_YES == rh->ac_tail->gns_authority)
- recursive_gns_resolution_revocation (rh);
- else
- recursive_dns_resolution (rh);
- }
- /**
- * Begin the resolution process from 'name', starting with
- * the identification of the zone specified by 'name'.
- *
- * @param rh resolution to perform
- */
- static void
- start_resolver_lookup (struct GNS_ResolverHandle *rh)
- {
- struct AuthorityChain *ac;
- char *y;
- struct in_addr v4;
- struct in6_addr v6;
- if (1 == inet_pton (AF_INET,
- rh->name,
- &v4))
- {
- /* name is IPv4 address, pretend it's an A record */
- struct GNUNET_GNSRECORD_Data rd;
- rd.data = &v4;
- rd.data_size = sizeof (v4);
- rd.expiration_time = UINT64_MAX;
- rd.record_type = GNUNET_DNSPARSER_TYPE_A;
- rd.flags = 0;
- rh->proc (rh->proc_cls, 1, &rd);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- if (1 == inet_pton (AF_INET6,
- rh->name,
- &v6))
- {
- /* name is IPv6 address, pretend it's an AAAA record */
- struct GNUNET_GNSRECORD_Data rd;
- rd.data = &v6;
- rd.data_size = sizeof (v6);
- rd.expiration_time = UINT64_MAX;
- rd.record_type = GNUNET_DNSPARSER_TYPE_AAAA;
- rd.flags = 0;
- rh->proc (rh->proc_cls, 1, &rd);
- GNS_resolver_lookup_cancel (rh);
- return;
- }
- if ( ( (GNUNET_YES == is_canonical (rh->name)) &&
- (0 != strcmp (GNUNET_GNS_TLD, rh->name)) ) ||
- ( (GNUNET_YES != is_gnu_tld (rh->name)) &&
- (GNUNET_YES != is_zkey_tld (rh->name)) ) )
- {
- /* use standard DNS lookup */
- int af;
- switch (rh->record_type)
- {
- case GNUNET_DNSPARSER_TYPE_A:
- af = AF_INET;
- break;
- case GNUNET_DNSPARSER_TYPE_AAAA:
- af = AF_INET6;
- break;
- default:
- af = AF_UNSPEC;
- break;
- }
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Doing standard DNS lookup for `%s'\n",
- rh->name);
- rh->std_resolve = GNUNET_RESOLVER_ip_get (rh->name,
- af,
- DNS_LOOKUP_TIMEOUT,
- &handle_dns_result,
- rh);
- return;
- }
- if (is_zkey_tld (rh->name))
- {
- /* Name ends with ".zkey", try to replace authority zone with zkey
- authority */
- GNUNET_free (resolver_lookup_get_next_label (rh)); /* will return "zkey" */
- y = resolver_lookup_get_next_label (rh); /* will return 'y' coordinate */
- if ( (NULL == y) ||
- (GNUNET_OK !=
- GNUNET_CRYPTO_ecdsa_public_key_from_string (y,
- strlen (y),
- &rh->authority_zone)) )
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _("Hostname `%s' is not well-formed, resolution fails\n"),
- rh->name);
- rh->task_id = GNUNET_SCHEDULER_add_now (&fail_resolution, rh);
- }
- GNUNET_free_non_null (y);
- }
- else
- {
- /* Name ends with ".gnu", eat ".gnu" and continue with resolution */
- GNUNET_free (resolver_lookup_get_next_label (rh));
- }
- ac = GNUNET_new (struct AuthorityChain);
- ac->rh = rh;
- ac->label = resolver_lookup_get_next_label (rh);
- ac->suggested_shortening_label = NULL;
- if (NULL == ac->label)
- /* name was just "gnu", so we default to label '+' */
- ac->label = GNUNET_strdup (GNUNET_GNS_MASTERZONE_STR);
- ac->gns_authority = GNUNET_YES;
- ac->authority_info.gns_authority = rh->authority_zone;
- GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
- rh->ac_tail,
- ac);
- rh->task_id = GNUNET_SCHEDULER_add_now (&recursive_resolution,
- rh);
- }
- /**
- * Lookup of a record in a specific zone calls lookup result processor
- * on result.
- *
- * @param zone the zone to perform the lookup in
- * @param record_type the record type to look up
- * @param name the name to look up
- * @param shorten_key a private key for use with PSEU import (can be NULL)
- * @param options local options to control local lookup
- * @param proc the processor to call on result
- * @param proc_cls the closure to pass to @a proc
- * @return handle to cancel operation
- */
- struct GNS_ResolverHandle *
- GNS_resolver_lookup (const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
- uint32_t record_type,
- const char *name,
- const struct GNUNET_CRYPTO_EcdsaPrivateKey *shorten_key,
- enum GNUNET_GNS_LocalOptions options,
- GNS_ResultProcessor proc, void *proc_cls)
- {
- struct GNS_ResolverHandle *rh;
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- (NULL == shorten_key)
- ? "Starting lookup for `%s' with shortening disabled\n"
- : "Starting lookup for `%s' with shortening enabled\n",
- name);
- rh = GNUNET_new (struct GNS_ResolverHandle);
- GNUNET_CONTAINER_DLL_insert (rlh_head,
- rlh_tail,
- rh);
- rh->authority_zone = *zone;
- rh->proc = proc;
- rh->proc_cls = proc_cls;
- rh->options = options;
- rh->record_type = record_type;
- rh->name = GNUNET_strdup (name);
- rh->name_resolution_pos = strlen (name);
- if (NULL != shorten_key)
- {
- rh->shorten_key = GNUNET_new (struct GNUNET_CRYPTO_EcdsaPrivateKey);
- *rh->shorten_key = *shorten_key;
- }
- start_resolver_lookup (rh);
- return rh;
- }
- /**
- * Cancel active resolution (i.e. client disconnected).
- *
- * @param rh resolution to abort
- */
- void
- GNS_resolver_lookup_cancel (struct GNS_ResolverHandle *rh)
- {
- struct DnsResult *dr;
- struct AuthorityChain *ac;
- struct VpnContext *vpn_ctx;
- GNUNET_CONTAINER_DLL_remove (rlh_head,
- rlh_tail,
- rh);
- while (NULL != (ac = rh->ac_head))
- {
- GNUNET_CONTAINER_DLL_remove (rh->ac_head,
- rh->ac_tail,
- ac);
- GNUNET_free (ac->label);
- GNUNET_free_non_null (ac->suggested_shortening_label);
- GNUNET_free (ac);
- }
- if (NULL != rh->g2dc)
- {
- /* rh->g2dc->rh is NOT in the DLL yet, so to enable us
- using GNS_resolver_lookup_cancel here, we need to
- add it first... */
- if (NULL != rh->g2dc->rh)
- {
- GNUNET_CONTAINER_DLL_insert (rlh_head,
- rlh_tail,
- rh->g2dc->rh);
- GNS_resolver_lookup_cancel (rh->g2dc->rh);
- rh->g2dc->rh = NULL;
- }
- GNUNET_free (rh->g2dc->ns);
- GNUNET_free (rh->g2dc);
- rh->g2dc = NULL;
- }
- if (GNUNET_SCHEDULER_NO_TASK != rh->task_id)
- {
- GNUNET_SCHEDULER_cancel (rh->task_id);
- rh->task_id = GNUNET_SCHEDULER_NO_TASK;
- }
- if (NULL != rh->get_handle)
- {
- GNUNET_DHT_get_stop (rh->get_handle);
- rh->get_handle = NULL;
- }
- if (NULL != rh->dht_heap_node)
- {
- GNUNET_CONTAINER_heap_remove_node (rh->dht_heap_node);
- rh->dht_heap_node = NULL;
- }
- if (NULL != (vpn_ctx = rh->vpn_ctx))
- {
- GNUNET_VPN_cancel_request (vpn_ctx->vpn_request);
- GNUNET_free (vpn_ctx->rd_data);
- GNUNET_free (vpn_ctx);
- }
- if (NULL != rh->dns_request)
- {
- GNUNET_DNSSTUB_resolve_cancel (rh->dns_request);
- rh->dns_request = NULL;
- }
- if (NULL != rh->namecache_qe)
- {
- GNUNET_NAMECACHE_cancel (rh->namecache_qe);
- rh->namecache_qe = NULL;
- }
- if (NULL != rh->rev_check)
- {
- GNUNET_REVOCATION_query_cancel (rh->rev_check);
- rh->rev_check = NULL;
- }
- if (NULL != rh->std_resolve)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Canceling standard DNS resolution\n");
- GNUNET_RESOLVER_request_cancel (rh->std_resolve);
- rh->std_resolve = NULL;
- }
- while (NULL != (dr = rh->dns_result_head))
- {
- GNUNET_CONTAINER_DLL_remove (rh->dns_result_head,
- rh->dns_result_tail,
- dr);
- GNUNET_free (dr);
- }
- GNUNET_free_non_null (rh->shorten_key);
- GNUNET_free (rh->name);
- GNUNET_free (rh);
- }
- /* ***************** Resolver initialization ********************* */
- /**
- * Initialize the resolver
- *
- * @param nc the namecache handle
- * @param dht the dht handle
- * @param c configuration handle
- * @param max_bg_queries maximum number of parallel background queries in dht
- */
- void
- GNS_resolver_init (struct GNUNET_NAMECACHE_Handle *nc,
- struct GNUNET_DHT_Handle *dht,
- const struct GNUNET_CONFIGURATION_Handle *c,
- unsigned long long max_bg_queries)
- {
- char *dns_ip;
- cfg = c;
- namecache_handle = nc;
- dht_handle = dht;
- dht_lookup_heap =
- GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
- max_allowed_background_queries = max_bg_queries;
- if (GNUNET_SYSERR == (use_cache = GNUNET_CONFIGURATION_get_value_yesno (c,
- "gns",
- "USE_CACHE")))
- use_cache = GNUNET_YES;
- if (GNUNET_NO == use_cache)
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Namecache disabled\n");
- if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_string (c,
- "gns",
- "DNS_RESOLVER",
- &dns_ip))
- {
- /* user did not specify DNS resolver, use 8.8.8.8 */
- dns_ip = GNUNET_strdup ("8.8.8.8");
- }
- dns_handle = GNUNET_DNSSTUB_start (dns_ip);
- GNUNET_free (dns_ip);
- vpn_handle = GNUNET_VPN_connect (cfg);
- }
- /**
- * Shutdown resolver
- */
- void
- GNS_resolver_done ()
- {
- struct GNS_ResolverHandle *rh;
- struct CacheOps *co;
- /* abort active resolutions */
- while (NULL != (rh = rlh_head))
- {
- rh->proc (rh->proc_cls, 0, NULL);
- GNS_resolver_lookup_cancel (rh);
- }
- while (NULL != (co = co_head))
- {
- GNUNET_CONTAINER_DLL_remove (co_head,
- co_tail,
- co);
- GNUNET_NAMECACHE_cancel (co->namecache_qe_cache);
- GNUNET_free (co);
- }
- GNUNET_CONTAINER_heap_destroy (dht_lookup_heap);
- dht_lookup_heap = NULL;
- GNUNET_DNSSTUB_stop (dns_handle);
- dns_handle = NULL;
- GNUNET_VPN_disconnect (vpn_handle);
- vpn_handle = NULL;
- dht_handle = NULL;
- namecache_handle = NULL;
- }
- /* *************** common helper functions (do not really belong here) *********** */
- /**
- * Checks if @a name ends in ".TLD"
- *
- * @param name the name to check
- * @param tld the TLD to check for
- * @return GNUNET_YES or GNUNET_NO
- */
- int
- is_tld (const char* name, const char* tld)
- {
- size_t offset = 0;
- if (strlen (name) <= strlen (tld))
- return GNUNET_NO;
- offset = strlen (name) - strlen (tld);
- if (0 != strcmp (name + offset, tld))
- return GNUNET_NO;
- return GNUNET_YES;
- }
- /* end of gnunet-service-gns_resolver.c */
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