1 files changed, 244 insertions, 0 deletions

diff --git a/src/gns/gnunet-service-gns_reverser.c b/src/gns/gnunet-service-gns_reverser.c
new file mode 100644
index 000000000..6bae20b61
--- /dev/null
+++ b/src/gns/gnunet-service-gns_reverser.c
@@ -0,0 +1,244 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2009-2013 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
+     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., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
+*/
+/**
+ * @file gns/gnunet-service-gns_reverser.c
+ * @brief GNUnet GNS service
+ * @author Martin Schanzenbach
+ */
+
+
+#include "platform.h"
+#include "gnunet_gns_service.h"
+#include "gnunet-service-gns_resolver.h"
+#include "gnunet-service-gns_reverser.h"
+
+struct ReverseTreeNode
+{
+  /**
+   * DLL
+   */
+  struct ReverseTreeNode *next;
+
+  /**
+   * DLL
+   */
+  struct ReverseTreeNode *prev;
+
+  /**
+   * Resolved name until now
+   */
+  char *name;
+
+  /**
+   * Depth of the resolution at this node
+   */
+  uint8_t depth;
+
+  /**
+   * The pkey of the namespace
+   */
+  struct GNUNET_CRYPTO_EcdsaPublicKey pkey;
+
+};
+
+
+struct GNS_ReverserHandle
+{
+  /**
+   * GNS resolver handle
+   */
+  struct GNS_ResolverHandle *rh;
+
+  /**
+   * The authority to look for
+   */
+  struct GNUNET_CRYPTO_EcdsaPublicKey authority;
+  
+  /**
+   * Resolution candidate queue
+   */
+  struct ReverseTreeNode *node_queue_head;
+
+  /**
+   * Resolution candidate queue
+   */
+  struct ReverseTreeNode *node_queue_tail;
+
+  /**
+   * Max depth for the resolution
+   */
+  uint8_t max_depth;
+
+  /**
+   * Result callback
+   */
+  GNS_ReverseResultProcessor proc;
+
+  /**
+   * Callback closure
+   */
+  void *proc_cls;
+};
+
+void
+cleanup_handle (struct GNS_ReverserHandle *rh)
+{
+  struct ReverseTreeNode *rtn;
+
+  for (rtn = rh->node_queue_head; NULL != rtn; rtn = rh->node_queue_head)
+  {
+    if (NULL != rtn->name)
+      GNUNET_free (rtn->name);
+    GNUNET_CONTAINER_DLL_remove (rh->node_queue_head,
+                                 rh->node_queue_tail,
+                                 rtn);
+    GNUNET_free (rtn);
+  }
+}
+
+void
+handle_gns_result (void *cls,
+                   uint32_t rd_count,
+                   const struct GNUNET_GNSRECORD_Data *rd)
+{
+  struct GNS_ReverserHandle *rh = cls;
+  const struct GNUNET_GNSRECORD_ReverseRecord *rr;
+  struct ReverseTreeNode *rtn;
+  char *result;
+  const char *name;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Got result (%d)\n", rd_count);
+
+  for (int i = 0; i < rd_count; i++)
+  {
+    /**
+     * Check if we are in the delegation set
+     */
+    if (GNUNET_GNSRECORD_TYPE_REVERSE != rd[i].record_type)
+      continue;
+    rr = rd[i].data;
+    name = (const char*) &rr[1];
+    if (0 == memcmp (&rh->authority,
+                     &rr->pkey,
+                     sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey)))
+    {
+      //Found!
+      GNUNET_asprintf (&result,
+                       "%s.%s.gnu",
+                       rh->node_queue_head->name,
+                       name);
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Found path from %s\n", result);
+
+      rh->proc (rh->proc_cls, result);
+      cleanup_handle (rh);
+      GNUNET_free (result);
+      return;
+    } else {
+      if (rh->node_queue_head->depth >= rh->max_depth)
+        break;
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Found REVERSE from %s\n", name);
+
+      rtn = GNUNET_new (struct ReverseTreeNode);
+      if (NULL == rh->node_queue_head->name)
+        rtn->name = GNUNET_strdup (name);
+      else
+        GNUNET_asprintf (&rtn->name,
+                         "%s.%s",
+                         rh->node_queue_head->name,
+                         name);
+      rtn->depth = rh->node_queue_head->depth + 1;
+      rtn->pkey = rr->pkey;
+      GNUNET_CONTAINER_DLL_insert_tail (rh->node_queue_head,
+                                        rh->node_queue_tail,
+                                        rtn);
+    }
+  }
+
+  /**
+   * Done here remove node from queue
+   */
+  rtn = rh->node_queue_head;
+  GNUNET_CONTAINER_DLL_remove (rh->node_queue_head,
+                               rh->node_queue_tail,
+                               rtn);
+  if (NULL == rh->node_queue_head)
+  {
+    //No luck
+    rh->proc (rh->proc_cls, NULL);
+    cleanup_handle (rh);
+    return;
+  }
+  rh->rh = GNS_resolver_lookup (&rh->node_queue_head->pkey,
+                                GNUNET_GNSRECORD_TYPE_REVERSE,
+                                "+.gnu",
+                                NULL,
+                                GNUNET_GNS_LO_DEFAULT,
+                                &handle_gns_result,
+                                rh);
+}
+
+struct GNS_ReverserHandle *
+GNS_reverse_lookup (const struct GNUNET_CRYPTO_EcdsaPublicKey *target,
+                    const struct GNUNET_CRYPTO_EcdsaPublicKey *authority,
+                    GNS_ReverseResultProcessor proc,
+                    void *proc_cls)
+{
+  struct GNS_ReverserHandle *rh;
+  struct ReverseTreeNode *rtn;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Starting reverse resolution\n");
+  rh = GNUNET_new (struct GNS_ReverserHandle);
+  rh->proc = proc;
+  rh->proc_cls = proc_cls;
+  rtn = GNUNET_new (struct ReverseTreeNode);
+  rtn->name = NULL;
+  rtn->pkey = *target;
+  rtn->depth = 0;
+  GNUNET_CONTAINER_DLL_insert (rh->node_queue_head,
+                               rh->node_queue_tail,
+                               rtn);
+  rh->authority = *authority;
+  rh->max_depth = 3; //TODO make argument
+  rh->rh = GNS_resolver_lookup (target,
+                                GNUNET_GNSRECORD_TYPE_REVERSE,
+                                "+.gnu",
+                                NULL,
+                                GNUNET_GNS_LO_DEFAULT,
+                                &handle_gns_result,
+                                rh);
+  return rh;
+}
+
+/**
+ * Cancel active resolution (i.e. client disconnected).
+ *
+ * @param rh resolution to abort
+ */
+void
+GNS_reverse_lookup_cancel (struct GNS_ReverserHandle *rh)
+{
+  cleanup_handle (rh);
+  return;
+}
+
+