X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fmesh%2Fmesh_tunnel_tree.c;h=c2fe6c3d98776e90c4527d0882f42dd0d6228580;hb=0f6d24a229e9149db26a4e667ed25032d19f533a;hp=cfe6a46a80a222b31a601cfd93ec87b16ac8d48e;hpb=83b19539f4d322b43683f5838b72e9ec2c8e6073;p=oweals%2Fgnunet.git

diff --git a/src/mesh/mesh_tunnel_tree.c b/src/mesh/mesh_tunnel_tree.c
index cfe6a46a8..c2fe6c3d9 100644
--- a/src/mesh/mesh_tunnel_tree.c
+++ b/src/mesh/mesh_tunnel_tree.c
@@ -110,7 +110,7 @@ struct MeshTunnelTree
 /**
  * Create a new path
  *
- * @param lenght How many hops will the path have.
+ * @param length How many hops will the path have.
  *
  * @return A newly allocated path with a peer array of the specified length.
  */
@@ -132,7 +132,7 @@ path_new (unsigned int length)
 /**
  * Invert the path
  *
- * @param p the path to invert
+ * @param path the path to invert
  */
 void
 path_invert (struct MeshPeerPath *path)
@@ -152,7 +152,7 @@ path_invert (struct MeshPeerPath *path)
 /**
  * Duplicate a path, incrementing short peer's rc.
  *
- * @param p The path to duplicate.
+ * @param path The path to duplicate.
  */
 struct MeshPeerPath *
 path_duplicate (struct MeshPeerPath *path)
@@ -172,7 +172,7 @@ path_duplicate (struct MeshPeerPath *path)
  * Recusively update the info about what is the first hop to reach the node
  *
  * @param tree Tree this nodes belongs to.
- * @param parent_id Short ID from node form which to start updating.
+ * @param parent The node form which to start updating.
  * @param hop If known, ID of the first hop.
  *            If not known, NULL to find out and pass on children.
  */
@@ -181,53 +181,14 @@ tree_node_update_first_hops (struct MeshTunnelTree *tree,
                              struct MeshTunnelTreeNode *parent,
                              struct GNUNET_PeerIdentity *hop);
 
-/**
- * Find the first peer whom to send a packet to go down this path
- *
- * @param t The tunnel tree to use
- * @param peer The peerinfo of the peer we are trying to reach
- *
- * @return peerinfo of the peer who is the first hop in the tunnel
- *         NULL on error
- */
-struct GNUNET_PeerIdentity *
-path_get_first_hop (struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
-{
-  struct GNUNET_PeerIdentity id;
-  struct GNUNET_PeerIdentity *r;
-
-  GNUNET_PEER_resolve (peer, &id);
-  r = GNUNET_CONTAINER_multihashmap_get (t->first_hops, &id.hashPubKey);
-  if (NULL == r)
-  {
-    struct MeshTunnelTreeNode *n;
-
-    n = tree_find_peer (t, peer);
-    if (NULL != t->me && NULL != n)
-    {
-      tree_node_update_first_hops (t, n, NULL);
-      r = GNUNET_CONTAINER_multihashmap_get (t->first_hops, &id.hashPubKey);
-      GNUNET_assert (NULL != r);
-    }
-    else
-    {
-      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                  "Tree structure inconsistent! me: %p, n: %p", t->me, n);
-      GNUNET_break (0);
-    }
-  }
-
-  return r;
-}
-
 
 /**
- * Get the length of a path
+ * Get the length of a path.
  *
- * @param path The path to measure, with the local peer at any point of it
+ * @param path The path to measure, with the local peer at any point of it.
  *
- * @return Number of hops to reach destination
- *         UINT_MAX in case the peer is not in the path
+ * @return Number of hops to reach destination.
+ *         UINT_MAX in case the peer is not in the path.
  */
 unsigned int
 path_get_length (struct MeshPeerPath *path)
@@ -238,24 +199,6 @@ path_get_length (struct MeshPeerPath *path)
 }
 
 
-/**
- * Get the cost of the path relative to the already built tunnel tree
- *
- * @param t The tunnel tree to which compare
- * @param path The individual path to reach a peer
- *
- * @return Number of hops to reach destination, UINT_MAX in case the peer is not
- * in the path
- *
- * TODO: remove dummy implementation, look into the tunnel tree
- */
-unsigned int
-path_get_cost (struct MeshTunnelTree *t, struct MeshPeerPath *path)
-{
-  return path_get_length (path);
-}
-
-
 /**
  * Destroy the path and free any allocated resources linked to it
  *
@@ -269,7 +212,7 @@ path_destroy (struct MeshPeerPath *p)
   if (NULL == p)
     return GNUNET_OK;
   GNUNET_PEER_decrement_rcs (p->peers, p->length);
-  GNUNET_free (p->peers);
+  GNUNET_free_non_null (p->peers);
   GNUNET_free (p);
   return GNUNET_OK;
 }
@@ -306,7 +249,7 @@ tree_node_new (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer)
  * Recursively find the given peer.
  *
  * @param parent Node where to start looking.
- * @param peer Peer to find.
+ * @param peer_id Short ID of the peer to find.
  *
  * @return Pointer to the node of the peer. NULL if not found.
  */
@@ -332,7 +275,7 @@ tree_node_find_peer (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer_id)
  * Recusively update the info about what is the first hop to reach the node
  *
  * @param tree Tree this nodes belongs to.
- * @param parent_id Short ID from node form which to start updating.
+ * @param parent ID from node form which to start updating.
  * @param hop If known, ID of the first hop.
  *            If not known, NULL to find out and pass on children.
  */
@@ -360,8 +303,8 @@ tree_node_update_first_hops (struct MeshTunnelTree *tree,
     while (aux != tree->me)
     {
 #if MESH_TREE_DEBUG
-      GNUNET_PEER_resolve (old->peer, &id);
-      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   ... its not %s.\n",
+      GNUNET_PEER_resolve (aux->peer, &id);
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   ... checking %s.\n",
                   GNUNET_i2s (&id));
 #endif
       old = aux;
@@ -401,25 +344,25 @@ tree_node_debug (struct MeshTunnelTreeNode *n, uint16_t level)
   uint16_t i;
 
   for (i = 0; i < level; i++)
-    fprintf (stderr, "  ");
+    FPRINTF (stderr, "%s",  "  ");
   if (n->status == MESH_PEER_READY)
-    fprintf (stderr, "#");
+    FPRINTF (stderr, "%s",  "#");
   if (n->status == MESH_PEER_SEARCHING)
-    fprintf (stderr, "+");
+    FPRINTF (stderr, "%s",  "+");
   if (n->status == MESH_PEER_RELAY)
-    fprintf (stderr, "-");
+    FPRINTF (stderr, "%s",  "-");
   if (n->status == MESH_PEER_RECONNECTING)
-    fprintf (stderr, "*");
+    FPRINTF (stderr, "%s",  "*");
 
   GNUNET_PEER_resolve (n->peer, &id);
-  fprintf (stderr, "%s, [%u, %p] ", GNUNET_i2s (&id), n->peer, n);
+  FPRINTF (stderr, "%s, [%u, %p] ", GNUNET_i2s (&id), n->peer, n);
   if (NULL != n->parent)
   {
     GNUNET_PEER_resolve (n->parent->peer, &id);
-    fprintf (stderr, "(-> %s [%u])\n", GNUNET_i2s (&id), n->parent->peer);
+    FPRINTF (stderr, "(-> %s [%u])\n", GNUNET_i2s (&id), n->parent->peer);
   }
   else
-    fprintf (stderr, "(root)\n");
+    FPRINTF (stderr, "%s",  "(root)\n");
   for (c = n->children_head; NULL != c; c = c->next)
     tree_node_debug (c, level + 1);
 }
@@ -428,7 +371,7 @@ tree_node_debug (struct MeshTunnelTreeNode *n, uint16_t level)
 /**
  * Destroys and frees the node and all children
  *
- * @param n Parent node to be destroyed
+ * @param parent Parent node to be destroyed
  */
 static void
 tree_node_destroy (struct MeshTunnelTreeNode *parent)
@@ -436,6 +379,8 @@ tree_node_destroy (struct MeshTunnelTreeNode *parent)
   struct MeshTunnelTreeNode *n;
   struct MeshTunnelTreeNode *next;
 
+  if (NULL == parent)
+    return;
 #if MESH_TREE_DEBUG
   struct GNUNET_PeerIdentity id;
 
@@ -461,12 +406,11 @@ tree_node_destroy (struct MeshTunnelTreeNode *parent)
 
 
 /**
- * Create a new tunnel tree associated to a tunnel
+ * Create a new tree.
  *
- * @param t Tunnel this tree will represent
- * @param peer A short peer id of the root of the tree
+ * @param peer A short peer id of the root of the tree.
  *
- * @return A newly allocated and initialized tunnel tree
+ * @return A newly allocated and initialized tunnel tree.
  */
 struct MeshTunnelTree *
 tree_new (GNUNET_PEER_Id peer)
@@ -474,48 +418,25 @@ tree_new (GNUNET_PEER_Id peer)
   struct MeshTunnelTree *tree;
 
   tree = GNUNET_malloc (sizeof (struct MeshTunnelTree));
-  tree->first_hops = GNUNET_CONTAINER_multihashmap_create (32);
+  tree->first_hops = GNUNET_CONTAINER_multihashmap_create (32, GNUNET_NO);
   tree->root = tree_node_new (NULL, peer);
   tree->root->status = MESH_PEER_ROOT;
 
-  return tree;
-}
-
+  if (1 == peer)
+  {
+    tree->me = tree->root;
+  }
 
-/**
- * Set own identity in the tree
- *
- * @param tree Tree.
- * @param peer A short peer id of local peer.
- */
-void
-tree_set_me (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer)
-{
-  tree->me = tree_find_peer (tree, peer);
+  return tree;
 }
 
 
-/**
- * Get the id of the local node of the tree.
- *
- * @param tree Tree whose local id we want to now.
- *
- * @return Short peer id of local peer.
- */
-GNUNET_PEER_Id
-tree_get_me (struct MeshTunnelTree *tree)
-{
-  if (NULL != tree->me)
-    return tree->me->peer;
-  else
-    return (GNUNET_PEER_Id) 0;
-}
-
 /**
  * Set the status of a node.
  *
  * @param tree Tree.
- * @param peer A short peer id of local peer.
+ * @param peer A short peer id of the node.
+ * @param status New status to set.
  */
 void
 tree_set_status (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer,
@@ -533,9 +454,10 @@ tree_set_status (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer,
 /**
  * Get the status of a node.
  *
- * @param tree Tree whose local id we want to now.
+ * @param tree Tree whose node's status we want to now.
+ * @param peer A short peer id of the node.
  *
- * @return Short peer id of local peer.
+ * @return Status of the peer.
  */
 enum MeshPeerState
 tree_get_status (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer)
@@ -566,11 +488,53 @@ tree_get_predecessor (struct MeshTunnelTree *tree)
 }
 
 
+/**
+ * Find the first peer whom to send a packet to go down this path
+ *
+ * @param t The tunnel tree to use
+ * @param peer The peerinfo of the peer we are trying to reach
+ *
+ * @return peerinfo of the peer who is the first hop in the tunnel
+ *         NULL on error
+ *
+ * FIXME use PEER_Id
+ */
+struct GNUNET_PeerIdentity *
+tree_get_first_hop (struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
+{
+  struct GNUNET_PeerIdentity id;
+  struct GNUNET_PeerIdentity *r;
+
+  GNUNET_PEER_resolve (peer, &id);
+  r = GNUNET_CONTAINER_multihashmap_get (t->first_hops, &id.hashPubKey);
+  if (NULL == r)
+  {
+    struct MeshTunnelTreeNode *n;
+
+    n = tree_find_peer (t, peer);
+    if (NULL != t->me && NULL != n)
+    {
+      tree_node_update_first_hops (t, n, NULL);
+      r = GNUNET_CONTAINER_multihashmap_get (t->first_hops, &id.hashPubKey);
+      GNUNET_assert (NULL != r);
+    }
+    else
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                  "Tree structure inconsistent! me: %p, n: %p", t->me, n);
+      GNUNET_break (0);
+    }
+  }
+
+  return r;
+}
+
+
 /**
  * Find the given peer in the tree.
  *
  * @param tree Tree where to look for the peer.
- * @param peer Peer to find.
+ * @param peer_id Short ID of the peer to find.
  *
  * @return Pointer to the node of the peer. NULL if not found.
  */
@@ -587,6 +551,7 @@ tree_find_peer (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer_id)
  * @param tree Tree this node belongs to
  * @param parent Node to be clean, potentially with children
  * @param cb Callback to use to notify about disconnected peers.
+ * @param cbcls Closure for cb.
  */
 static void
 tree_mark_peers_disconnected (struct MeshTunnelTree *tree,
@@ -622,26 +587,117 @@ tree_mark_peers_disconnected (struct MeshTunnelTree *tree,
  *
  * @param tree Tree to use. Must have "me" set.
  * @param cb Callback to call over each child.
- * @param cls Closure.
+ * @param cb_cls Closure for @c cb.
  */
 void
 tree_iterate_children (struct MeshTunnelTree *tree, MeshTreeCallback cb,
-                       void *cls)
+                       void *cb_cls)
 {
   struct MeshTunnelTreeNode *n;
 
   if (NULL == tree->me)
-  {
-    GNUNET_break (0);
     return;
-  }
   for (n = tree->me->children_head; NULL != n; n = n->next)
   {
-    cb (cls, n->peer);
+    cb (cb_cls, n->peer);
+  }
+}
+
+
+/**
+ * Struct to contain a list of pending nodes when iterating a tree.
+ */
+struct MeshTreePendingNode {
+
+  /**
+   * DLL next.
+   */
+  struct MeshTreePendingNode *next;
+
+  /**
+   * DLL prev.
+   */
+  struct MeshTreePendingNode *prev;
+
+  /**
+   * Pending node.
+   */
+  struct MeshTunnelTreeNode *node;
+};
+
+
+/**
+ * Iterate over all nodes in the tree.
+ *
+ * @param tree Tree to use..
+ * @param cb Callback to call over each child.
+ * @param cb_cls Closure for @c cb.
+ *
+ * TODO: recursive implementation? (s/heap/stack/g)
+ */
+void
+tree_iterate_all (struct MeshTunnelTree *tree,
+                  MeshWholeTreeCallback cb,
+                  void *cb_cls)
+{
+  struct MeshTunnelTreeNode *parent;
+  struct MeshTunnelTreeNode *n;
+  struct MeshTreePendingNode *head;
+  struct MeshTreePendingNode *tail;
+  struct MeshTreePendingNode *pending;
+
+  cb (cb_cls, tree->root->peer, 0);
+  pending = GNUNET_malloc (sizeof (struct MeshTreePendingNode));
+  pending->node = tree->root;
+  head = tail = NULL;
+  GNUNET_CONTAINER_DLL_insert (head, tail, pending);
+
+  while (NULL != head)
+  {
+    pending = head;
+    parent = pending->node;
+    GNUNET_CONTAINER_DLL_remove (head, tail, pending);
+    GNUNET_free (pending);
+    for (n = parent->children_head; NULL != n; n = n->next)
+    {
+      cb (cb_cls, n->peer, parent->peer);
+      pending = GNUNET_malloc (sizeof (struct MeshTreePendingNode));
+      pending->node = n;
+      /* Insert_tail: breadth first, Insert: depth first */
+      GNUNET_CONTAINER_DLL_insert (head, tail, pending);
+    }
   }
 }
 
 
+/**
+ * Iterator to count the children in a tree.
+ */
+static void
+count_children_cb (void *cls, GNUNET_PEER_Id peer)
+{
+  unsigned int *i = cls;
+
+  (*i)++;
+}
+
+
+/**
+ * Count how many children does the local node have in the tree.
+ *
+ * @param tree Tree to use. Must have "me" set.
+ */
+unsigned int
+tree_count_children (struct MeshTunnelTree *tree)
+{
+  unsigned int i;
+
+  i = 0;
+  tree_iterate_children(tree, &count_children_cb, &i);
+  return i;
+}
+
+
 /**
  * Recusively update the info about what is the first hop to reach the node
  *
@@ -664,7 +720,7 @@ tree_update_first_hops (struct MeshTunnelTree *tree, GNUNET_PEER_Id parent_id,
  * a new path to it or destroy it explicitly, taking care of it's child nodes.
  *
  * @param t Tunnel tree where to delete the path from.
- * @param peer Destination peer whose path we want to remove.
+ * @param peer_id Short ID of the destination peer whose path we want to remove.
  * @param cb Callback to use to notify about disconnected peers.
  * @param cbcls Closure for cb.
  *
@@ -686,7 +742,7 @@ tree_del_path (struct MeshTunnelTree *t, GNUNET_PEER_Id peer_id,
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Deleting path to %s.\n",
               GNUNET_i2s (&id));
 #endif
-  if (peer_id == t->root->peer)
+  if (NULL == t->root || peer_id == t->root->peer)
     return NULL;
 
   for (n = t->disconnected_head; NULL != n; n = n->next)
@@ -708,7 +764,8 @@ tree_del_path (struct MeshTunnelTree *t, GNUNET_PEER_Id peer_id,
   GNUNET_CONTAINER_DLL_remove (parent->children_head, parent->children_tail, n);
   n->parent = NULL;
 
-  while (MESH_PEER_RELAY == parent->status && NULL == parent->children_head)
+  while (MESH_PEER_RELAY == parent->status &&
+         NULL == parent->children_head)
   {
 #if MESH_TREE_DEBUG
     GNUNET_PEER_resolve (parent->peer, &id);
@@ -716,6 +773,8 @@ tree_del_path (struct MeshTunnelTree *t, GNUNET_PEER_Id peer_id,
                 GNUNET_i2s (&id));
 #endif
     n = parent->parent;
+    if (parent == t->me)
+      t->me = NULL;
     tree_node_destroy (parent);
     parent = n;
   }
@@ -735,8 +794,8 @@ tree_del_path (struct MeshTunnelTree *t, GNUNET_PEER_Id peer_id,
  * Return a newly allocated individual path to reach a peer from the local peer,
  * according to the path tree of some tunnel.
  *
- * @param t Tunnel from which to read the path tree
- * @param peer_info Destination peer to whom we want a path
+ * @param t Tunnel from which to read the path tree.
+ * @param peer Short ID of the destination peer to whom we want a path.
  *
  * @return A newly allocated individual path to reach the destination peer.
  *         Path must be destroyed afterwards.
@@ -746,24 +805,30 @@ tree_get_path_to_peer (struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
 {
   struct MeshTunnelTreeNode *n;
   struct MeshPeerPath *p;
-  GNUNET_PEER_Id myid = t->me->peer;
 
   n = tree_find_peer (t, peer);
   if (NULL == n)
+  {
+    GNUNET_break (0);
     return NULL;
+  }
   p = path_new (0);
 
   /* Building the path (inverted!) */
-  while (n->peer != myid)
+  while (n->peer != 1)
   {
     GNUNET_array_append (p->peers, p->length, n->peer);
     GNUNET_PEER_change_rc (n->peer, 1);
     n = n->parent;
     if (NULL == n)
+    {
+      GNUNET_break (0);
+      path_destroy (p);
       return NULL;
+    }
   }
-  GNUNET_array_append (p->peers, p->length, myid);
-  GNUNET_PEER_change_rc (myid, 1);
+  GNUNET_array_append (p->peers, p->length, 1);
+  GNUNET_PEER_change_rc (1, 1);
 
   path_invert (p);
 
@@ -802,7 +867,6 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
   struct MeshTunnelTreeNode *n;
   struct MeshTunnelTreeNode *c;
   struct GNUNET_PeerIdentity id;
-  GNUNET_PEER_Id myid;
   int me;
   unsigned int i;
 
@@ -813,10 +877,6 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
               GNUNET_i2s (&id));
 #endif
 
-  if (NULL != t->me)
-    myid = t->me->peer;
-  else
-    myid = 0;
   GNUNET_assert (0 != p->length);
   parent = n = t->root;
   if (n->peer != p->peers[0])
@@ -833,7 +893,7 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
    * - Length of the path is expected to be log N (size of whole network).
    * - Each level of the tree is expected to have log n children (size of tree).
    */
-  me = t->root->peer == myid ? 0 : -1;
+  me = t->root->peer == 1 ? 0 : -1;
   for (i = 1; i < p->length; i++)
   {
 #if MESH_TREE_DEBUG
@@ -842,7 +902,7 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
                 GNUNET_i2s (&id));
 #endif
     parent = n;
-    if (p->peers[i] == myid)
+    if (p->peers[i] == 1)
       me = i;
     for (c = n->children_head; NULL != c; c = c->next)
     {
@@ -875,7 +935,7 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Adding peer %s.\n",
                 GNUNET_i2s (&id));
     GNUNET_PEER_resolve (parent->peer, &id);
-    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:     to %s.\n",
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:            to %s.\n",
                 GNUNET_i2s (&id));
 #endif
 
@@ -898,14 +958,19 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
 #endif
       n = tree_node_new (parent, p->peers[i]);
       n->status = MESH_PEER_RELAY;
-      if (n->peer == myid)
-        t->me = n;
+    }
+    if (n->peer == 1)
+    {
+      t->me = n;
+      me = i;
     }
     i++;
     parent = n;
   }
   n->status = MESH_PEER_SEARCHING;
 
+  GNUNET_break (-1 != me);
+
   /* Add info about first hop into hashmap. */
   if (-1 != me && me < p->length - 1)
   {
@@ -915,11 +980,19 @@ tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
                 p->length - 1);
 #endif
     GNUNET_PEER_resolve (p->peers[me + 1], &id);
-    tree_update_first_hops (t, p->peers[p->length - 1], &id);
+    tree_update_first_hops (t, p->peers[me + 1], &id);
   }
 #if MESH_TREE_DEBUG
+  else
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                "MESH:   was last in path, not updating first hops (%d/%u)\n",
+                me, p->length - 1);
+  }
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   New node added.\n");
 #endif
+  if (NULL == t->me)
+    t->me = tree_find_peer (t, 1);
   return GNUNET_OK;
 }
 
@@ -995,7 +1068,6 @@ tree_del_peer (struct MeshTunnelTree *t, GNUNET_PEER_Id peer,
     GNUNET_break (0);
     return GNUNET_YES;
   }
-  GNUNET_break_op (NULL == n->children_head);
   tree_node_destroy (n);
   if (NULL == t->root->children_head && t->me != t->root)
   {
@@ -1007,6 +1079,52 @@ tree_del_peer (struct MeshTunnelTree *t, GNUNET_PEER_Id peer,
 }
 
 
+
+/**
+ * Get the cost of the path relative to the already built tunnel tree.
+ *
+ * @param t The tunnel tree to which compare.
+ * @param path The individual path to reach a peer. It has to start at the
+ *             root of the tree to be comparable.
+ *
+ * @return Number of hops to reach destination, UINT_MAX in case the peer is not
+ *         in the path.
+ *
+ * TODO: adapt to allow any start / root combination
+ * TODO: take in account state of the nodes
+ */
+unsigned int
+tree_get_path_cost (struct MeshTunnelTree *t, struct MeshPeerPath *path)
+{
+  struct MeshTunnelTreeNode *n;
+  struct MeshTunnelTreeNode *p;
+  unsigned int i;
+  unsigned int l;
+
+  l = path_get_length (path);
+  p = t->root;
+  if (t->root->peer != path->peers[0])
+  {
+    GNUNET_break (0);
+    return UINT_MAX;
+  }
+  for (i = 1; i < l; i++)
+  {
+    for (n = p->children_head; NULL != n; n = n->next)
+    {
+      if (path->peers[i] == n->peer)
+      {
+        break;
+      }
+    }
+    if (NULL == n)
+      return l - i;
+    p = n;
+  }
+  return l - i;
+}
+
+
 /**
  * Print the tree on stderr
  *
@@ -1016,6 +1134,8 @@ void
 tree_debug (struct MeshTunnelTree *t)
 {
   tree_node_debug (t->root, 0);
+  FPRINTF (stderr, "root: %p\n", t->root);
+  FPRINTF (stderr, "me:   %p\n", t->me);
 }
 
 
@@ -1029,7 +1149,7 @@ tree_debug (struct MeshTunnelTree *t)
  * @return GNUNET_YES if we should continue to iterate, GNUNET_NO if not.
  */
 static int
-iterate_free (void *cls, const GNUNET_HashCode * key, void *value)
+iterate_free (void *cls, const struct GNUNET_HashCode * key, void *value)
 {
   GNUNET_free (value);
   return GNUNET_YES;