small API change: do no longer pass rarely needed GNUNET_SCHEDULER_TaskContext to...
[oweals/gnunet.git] / src / gns / gnunet-service-gns_resolver.c
index 8f21b0d135868af269ae093388d0da9562e8e849..daae46ab7caa3291bc56acf203d0e44817baac2f 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2011-2013 Christian Grothoff (and other contributing authors)
+     Copyright (C) 2011-2013 GNUnet e.V.
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
@@ -14,8 +14,8 @@
 
      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.
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
 */
 
 /**
  * @brief GNU Name System resolver logic
  * @author Martin Schanzenbach
  * @author Christian Grothoff
- *
- * TODO:
- * - GNS: handle special SRV names --- no delegation, direct lookup;
- *        can likely be done in 'resolver_lookup_get_next_label'. (#3003)
- * - revocation checks (use REVOCATION service!), (#3004)
- * - DNAME support (#3005)
  */
 #include "platform.h"
 #include "gnunet_util_lib.h"
@@ -41,6 +35,7 @@
 #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"
@@ -56,7 +51,7 @@
 /**
  * Default timeout for DNS lookups.
  */
-#define DNS_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
+#define DNS_LOOKUP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
 
 /**
  * Default timeout for VPN redirections.
@@ -100,6 +95,16 @@ struct AuthorityChain
    */
   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.
@@ -163,7 +168,7 @@ struct DnsResult
 
   /**
    * Expiration time for the DNS record, 0 if we didn't
-   * get anything useful (i.e. 'gethostbyname' was used).
+   * get anything useful (i.e. 'gethostbyname()' was used).
    */
   uint64_t expiration_time;
 
@@ -329,7 +334,7 @@ struct GNS_ResolverHandle
   /**
    * ID of a task associated with the resolution process.
    */
-  GNUNET_SCHEDULER_TaskIdentifier task_id;
+  struct GNUNET_SCHEDULER_Task * task_id;
 
   /**
    * The name to resolve
@@ -354,7 +359,19 @@ struct GNS_ResolverHandle
   /**
    * Use only cache
    */
-  int only_cached;
+  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.
@@ -445,42 +462,15 @@ static struct CacheOps *co_head;
  */
 static struct CacheOps *co_tail;
 
-
 /**
- * Global configuration.
+ * Use namecache
  */
-static const struct GNUNET_CONFIGURATION_Handle *cfg;
+static int use_cache;
 
-#if 0
 /**
- * Check if name is in srv format (_x._y.xxx)
- *
- * @param name
- * @return #GNUNET_YES if true
+ * Global configuration.
  */
-static int
-is_srv (const char *name)
-{
-  char *ndup;
-  int ret;
-
-  if (*name != '_')
-    return GNUNET_NO;
-  if (NULL == strstr (name, "._"))
-    return GNUNET_NO;
-  ret = GNUNET_YES;
-  ndup = GNUNET_strdup (name);
-  strtok (ndup, ".");
-  if (NULL == strtok (NULL, "."))
-    ret = GNUNET_NO;
-  if (NULL == strtok (NULL, "."))
-    ret = GNUNET_NO;
-  if (NULL != strtok (NULL, "."))
-    ret = GNUNET_NO;
-  GNUNET_free (ndup);
-  return ret;
-}
-#endif
+static const struct GNUNET_CONFIGURATION_Handle *cfg;
 
 
 /**
@@ -551,15 +541,13 @@ translate_dot_plus (struct GNS_ResolverHandle *rh,
  * 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)
+fail_resolution (void *cls)
 {
   struct GNS_ResolverHandle *rh = cls;
 
-  rh->task_id = GNUNET_SCHEDULER_NO_TASK;
+  rh->task_id = NULL;
   rh->proc (rh->proc_cls, 0, NULL);
   GNS_resolver_lookup_cancel (rh);
 }
@@ -568,7 +556,7 @@ fail_resolution (void *cls,
 #if (defined WINDOWS) || (defined DARWIN)
 /* Don't have this on W32, here's a naive implementation
  * Was somehow removed on OS X ...  */
-void *
+static void *
 memrchr (const void *s,
         int c,
         size_t n)
@@ -586,7 +574,17 @@ memrchr (const void *s,
 
 /**
  * Get the next, rightmost label from the name that we are trying to resolve,
- * and update the resolution position accordingly.
+ * 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
@@ -597,10 +595,17 @@ 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);
+  dot = memrchr (rh->name,
+                 (int) '.',
+                 rh->name_resolution_pos);
   if (NULL == dot)
   {
     /* done, this was the last one */
@@ -615,7 +620,53 @@ resolver_lookup_get_next_label (struct GNS_ResolverHandle *rh)
     rp = dot + 1;
     rh->name_resolution_pos = dot - rh->name;
   }
-  return GNUNET_strndup (rp, len);
+  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;
 }
 
 
@@ -714,15 +765,15 @@ handle_dns_result (void *cls,
   const struct sockaddr_in *sa4;
   const struct sockaddr_in6 *sa6;
 
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Received %u bytes of DNS IP data\n",
-             addrlen);
   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:
@@ -755,8 +806,7 @@ handle_dns_result (void *cls,
  * @param tc task context
  */
 static void
-recursive_resolution (void *cls,
-                     const struct GNUNET_SCHEDULER_TaskContext *tc);
+recursive_resolution (void *cls);
 
 
 /**
@@ -792,7 +842,7 @@ dns_result_parser (void *cls,
 
   rh->dns_request = NULL;
   GNUNET_SCHEDULER_cancel (rh->task_id);
-  rh->task_id = GNUNET_SCHEDULER_NO_TASK;
+  rh->task_id = NULL;
   p = GNUNET_DNSPARSER_parse ((const char *) dns,
                              dns_len);
   if (NULL == p)
@@ -813,11 +863,11 @@ dns_result_parser (void *cls,
     {
       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;
     }
-  /* FIXME: add DNAME support */
 
   /* convert from (parsed) DNS to (binary) GNS format! */
   rd_count = p->num_answers + p->num_authority_records + p->num_additional_records;
@@ -838,7 +888,7 @@ dns_result_parser (void *cls,
       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];
+       rec = &p->additional_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... */
@@ -1075,12 +1125,8 @@ handle_gns_cname_result (struct GNS_ResolverHandle *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);
-    /* tigger shortening */
-    if (NULL != rh->shorten_key)
-      GNS_shorten_start (rh->ac_tail->label,
-                         NULL,
-                        &ac->authority_info.gns_authority,
-                        rh->shorten_key);
+    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,
@@ -1092,6 +1138,7 @@ handle_gns_cname_result (struct GNS_ResolverHandle *rh,
   /* 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);
 }
 
@@ -1329,23 +1376,22 @@ handle_gns_resolution_result (void *cls,
 {
   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;
-  const char *suggested_label;
   struct GNUNET_HashCode vhash;
   int af;
   char scratch[UINT16_MAX];
   size_t scratch_off;
   size_t scratch_start;
   size_t off;
-  int c2;
   struct GNUNET_GNSRECORD_Data rd_new[rd_count];
   unsigned int rd_off;
 
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+  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),
@@ -1387,7 +1433,7 @@ handle_gns_resolution_result (void *cls,
        case GNUNET_GNSRECORD_TYPE_VPN:
          {
            af = (GNUNET_DNSPARSER_TYPE_A == rh->record_type) ? AF_INET : AF_INET6;
-           if (sizeof (struct GNUNET_TUN_GnsVpnRecord) <
+           if (sizeof (struct GNUNET_TUN_GnsVpnRecord) >
                rd[i].data_size)
            {
              GNUNET_break_op (0);
@@ -1404,19 +1450,26 @@ handle_gns_resolution_result (void *cls,
              GNS_resolver_lookup_cancel (rh);
              return;
            }
-           GNUNET_CRYPTO_hash (vname,
-                               strlen (vname), // FIXME: +1?
-                               &vhash);
+           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);
-           (void) GNUNET_GNSRECORD_records_serialize (rd_count,
-                                                      rd,
-                                                      vpn_ctx->rd_data_size,
-                                                      vpn_ctx->rd_data);
+            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),
@@ -1424,7 +1477,7 @@ handle_gns_resolution_result (void *cls,
                                                                &vhash,
                                                                GNUNET_TIME_relative_to_absolute (VPN_TIMEOUT),
                                                                &vpn_allocation_cb,
-                                                               rh);
+                                                               vpn_ctx);
            return;
          }
        case GNUNET_GNSRECORD_TYPE_GNS2DNS:
@@ -1436,15 +1489,21 @@ handle_gns_resolution_result (void *cls,
          }
        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
@@ -1566,10 +1625,7 @@ handle_gns_resolution_result (void *cls,
          struct GNUNET_DNSPARSER_SrvRecord *srv;
 
          off = 0;
-         /* FIXME: passing rh->name here is is not necessarily what we want
-            (SRV support not finished) */
-         srv = GNUNET_DNSPARSER_parse_srv (rh->name,
-                                           rd[i].data,
+         srv = GNUNET_DNSPARSER_parse_srv (rd[i].data,
                                            rd[i].data_size,
                                            &off);
          if ( (NULL == srv) ||
@@ -1579,7 +1635,6 @@ handle_gns_resolution_result (void *cls,
          }
          else
          {
-           srv->domain_name = translate_dot_plus (rh, srv->domain_name);
            srv->target = translate_dot_plus (rh, srv->target);
            scratch_start = scratch_off;
            if (GNUNET_OK !=
@@ -1601,6 +1656,22 @@ handle_gns_resolution_result (void *cls,
            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;
@@ -1611,24 +1682,6 @@ handle_gns_resolution_result (void *cls,
            break;
          }
          memcpy (&pub, rd[i].data, rd[i].data_size);
-
-          /* tigger shortening */
-          if (NULL != rh->shorten_key)
-          {
-            suggested_label = NULL;
-            for (c2 = 0; c2< rd_count; c2++)
-            {
-              if ((GNUNET_GNSRECORD_TYPE_NICK ==rd[c2].record_type) &&
-                  (rd[i].data_size > 0) &&
-                  (((const char *) rd[c2].data)[rd[c2].data_size -1] == '\0'))
-                suggested_label = (const char *) rd->data;
-            }
-            if (NULL != suggested_label)
-              GNS_shorten_start (rh->ac_tail->label,
-                               suggested_label,
-                               &pub,
-                               rh->shorten_key);
-          }
           rd_off++;
           if (GNUNET_GNSRECORD_TYPE_PKEY != rh->record_type)
           {
@@ -1640,6 +1693,8 @@ handle_gns_resolution_result (void *cls,
             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);
@@ -1652,14 +1707,63 @@ handle_gns_resolution_result (void *cls,
       case GNUNET_GNSRECORD_TYPE_GNS2DNS:
         {
           /* delegation to DNS */
+          if (GNUNET_GNSRECORD_TYPE_GNS2DNS == rh->record_type)
+          {
+            rd_off++;
+            break; /* do not follow to DNS, we wanted the GNS2DNS record! */
+          }
           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 */
@@ -1691,27 +1795,12 @@ handle_gns_resolution_result (void *cls,
       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);
-      /* tigger shortening */
-      if (NULL != rh->shorten_key)
-      {
-        suggested_label = NULL;
-        for (c2 = 0; c2< rd_count; c2++)
-        {
-          if ((GNUNET_GNSRECORD_TYPE_NICK ==rd[c2].record_type) &&
-              (rd[c2].data_size > 0) &&
-              ((const char *) rd[c2].data)[rd[c2].data_size -1] == '\0')
-            suggested_label = (const char *) rd[c2].data;
-        }
-        if (NULL != suggested_label)
-          GNS_shorten_start (rh->ac_tail->label,
-                          suggested_label,
-                          &ac->authority_info.gns_authority,
-                          rh->shorten_key);
-      }
       /* add AC to tail */
       GNUNET_CONTAINER_DLL_insert_tail (rh->ac_head,
                                        rh->ac_tail,
@@ -1752,6 +1841,7 @@ handle_gns_resolution_result (void *cls,
            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);
@@ -1760,7 +1850,7 @@ handle_gns_resolution_result (void *cls,
         g2dc->rh->proc = &handle_gns2dns_result;
         g2dc->rh->proc_cls = rh;
         g2dc->rh->record_type = GNUNET_GNSRECORD_TYPE_ANY;
-        g2dc->rh->only_cached = GNUNET_NO;
+        g2dc->rh->options = GNUNET_GNS_LO_DEFAULT;
         g2dc->rh->loop_limiter = rh->loop_limiter + 1;
         rh->g2dc = g2dc;
         start_resolver_lookup (g2dc->rh);
@@ -1907,7 +1997,7 @@ handle_dht_response (void *cls,
   }
   /* Cache well-formed blocks */
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-             "Caching response from the DHT in namestore\n");
+             "Caching response from the DHT in namecache\n");
   co = GNUNET_new (struct CacheOps);
   co->namecache_qe_cache = GNUNET_NAMECACHE_block_cache (namecache_handle,
                                                         block,
@@ -1920,57 +2010,101 @@ handle_dht_response (void *cls,
 
 
 /**
- * Process a record that was stored in the namestore.
+ * 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 block block that was stored in the namestore
+ * @param rd_count number of entries in @a rd array
+ * @param rd array of records with data to store
  */
 static void
-handle_namestore_block_response (void *cls,
+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 GNS_ResolverHandle *rx;
   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_GNSRECORD_query_from_public_key (auth,
-                                         label,
-                                         &query);
   GNUNET_assert (NULL != rh->namecache_qe);
   rh->namecache_qe = NULL;
-  if ( (GNUNET_NO == rh->only_cached) &&
+  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) ) )
   {
-    /* Namestore knows nothing; try DHT lookup */
+    /* 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\n",
-               ac->label,
-               GNUNET_GNSRECORD_z2s (&ac->authority_info.gns_authority));
-    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);
-    }
+                "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) )
   {
@@ -1987,24 +2121,32 @@ handle_namestore_block_response (void *cls,
       GNUNET_GNSRECORD_block_decrypt (block,
                                      auth,
                                      label,
-                                     &handle_gns_resolution_result,
+                                     &handle_gns_namecache_resolution_result,
                                      rh))
   {
     GNUNET_break_op (0); /* block was ill-formed */
-    rh->proc (rh->proc_cls, 0, NULL);
-    GNS_resolver_lookup_cancel (rh);
+    /* 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 namestore.
+ * Lookup tail of our authority chain in the namecache.
  *
  * @param rh query we are processing
  */
 static void
-recursive_gns_resolution_namestore (struct GNS_ResolverHandle *rh)
+recursive_gns_resolution_namecache (struct GNS_ResolverHandle *rh)
 {
   struct AuthorityChain *ac = rh->ac_tail;
   struct GNUNET_HashCode query;
@@ -2016,11 +2158,19 @@ recursive_gns_resolution_namestore (struct GNS_ResolverHandle *rh)
   GNUNET_GNSRECORD_query_from_public_key (&ac->authority_info.gns_authority,
                                          ac->label,
                                          &query);
-  rh->namecache_qe = GNUNET_NAMECACHE_lookup_block (namecache_handle,
-                                                   &query,
-                                                   &handle_namestore_block_response,
-                                                   rh);
-  GNUNET_assert (NULL != rh->namecache_qe);
+  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);
+  }
 }
 
 
@@ -2047,7 +2197,7 @@ handle_revocation_result (void *cls,
     GNS_resolver_lookup_cancel (rh);
     return;
   }
-  recursive_gns_resolution_namestore (rh);
+  recursive_gns_resolution_namecache (rh);
 }
 
 
@@ -2076,15 +2226,13 @@ recursive_gns_resolution_revocation (struct GNS_ResolverHandle *rh)
  * 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)
+recursive_resolution (void *cls)
 {
   struct GNS_ResolverHandle *rh = cls;
 
-  rh->task_id = GNUNET_SCHEDULER_NO_TASK;
+  rh->task_id = NULL;
   if (MAX_RECURSION < rh->loop_limiter++)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
@@ -2204,6 +2352,7 @@ start_resolver_lookup (struct GNS_ResolverHandle *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);
@@ -2225,7 +2374,7 @@ start_resolver_lookup (struct GNS_ResolverHandle *rh)
  * @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 only_cached #GNUNET_NO to only check locally not DHT for performance
+ * @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
@@ -2235,7 +2384,7 @@ GNS_resolver_lookup (const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
                     uint32_t record_type,
                     const char *name,
                     const struct GNUNET_CRYPTO_EcdsaPrivateKey *shorten_key,
-                    int only_cached,
+                    enum GNUNET_GNS_LocalOptions options,
                     GNS_ResultProcessor proc, void *proc_cls)
 {
   struct GNS_ResolverHandle *rh;
@@ -2252,7 +2401,7 @@ GNS_resolver_lookup (const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
   rh->authority_zone = *zone;
   rh->proc = proc;
   rh->proc_cls = proc_cls;
-  rh->only_cached = only_cached;
+  rh->options = options;
   rh->record_type = record_type;
   rh->name = GNUNET_strdup (name);
   rh->name_resolution_pos = strlen (name);
@@ -2287,6 +2436,7 @@ GNS_resolver_lookup_cancel (struct GNS_ResolverHandle *rh)
                                 rh->ac_tail,
                                 ac);
     GNUNET_free (ac->label);
+    GNUNET_free_non_null (ac->suggested_shortening_label);
     GNUNET_free (ac);
   }
   if (NULL != rh->g2dc)
@@ -2306,10 +2456,10 @@ GNS_resolver_lookup_cancel (struct GNS_ResolverHandle *rh)
     GNUNET_free (rh->g2dc);
     rh->g2dc = NULL;
   }
-  if (GNUNET_SCHEDULER_NO_TASK != rh->task_id)
+  if (NULL != rh->task_id)
   {
     GNUNET_SCHEDULER_cancel (rh->task_id);
-    rh->task_id = GNUNET_SCHEDULER_NO_TASK;
+    rh->task_id = NULL;
   }
   if (NULL != rh->get_handle)
   {
@@ -2387,6 +2537,13 @@ GNS_resolver_init (struct GNUNET_NAMECACHE_Handle *nc,
   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",