X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fmesh%2Fmesh_tunnel_tree.c;h=a7577e36f8b14b810aed41975cf8b7a470234594;hb=c4f0fe3ea5a5ca3ce1f7dfecef719da631e4c6ac;hp=d052a3c4deecf057bff7dfa3a114df4cd23d45fa;hpb=1c468a36db041ad0c0bb0aaf6750f4a6df30d84a;p=oweals%2Fgnunet.git

diff --git a/src/mesh/mesh_tunnel_tree.c b/src/mesh/mesh_tunnel_tree.c
index d052a3c4d..a7577e36f 100644
--- a/src/mesh/mesh_tunnel_tree.c
+++ b/src/mesh/mesh_tunnel_tree.c
@@ -30,10 +30,87 @@
 #define MESH_TREE_DEBUG GNUNET_YES
 
 
+/**
+ * Node of path tree for a tunnel
+ */
+struct MeshTunnelTreeNode
+{
+  /**
+   * Peer this node describes
+   */
+  GNUNET_PEER_Id peer;
+
+  /**
+   * Parent node in the tree
+   */
+  struct MeshTunnelTreeNode *parent;
+
+  /**
+   * DLL of siblings
+   */
+  struct MeshTunnelTreeNode *next;
+
+  /**
+   * DLL of siblings
+   */
+  struct MeshTunnelTreeNode *prev;
+
+  /**
+   * DLL of children
+   */
+  struct MeshTunnelTreeNode *children_head;
+
+  /**
+   * DLL of children
+   */
+  struct MeshTunnelTreeNode *children_tail;
+
+    /**
+     * Status of the peer in the tunnel
+     */
+  enum MeshPeerState status;
+};
+
+
+/**
+ * Tree to reach all peers in the tunnel
+ */
+struct MeshTunnelTree
+{
+  /**
+   * Root node of peer tree
+   */
+  struct MeshTunnelTreeNode *root;
+
+  /**
+   * Node that represents our position in the tree (for non local tunnels)
+   */
+  struct MeshTunnelTreeNode *me;
+
+  /**
+   * DLL of disconneted nodes
+   */
+  struct MeshTunnelTreeNode *disconnected_head;
+
+  /**
+   * DLL of disconneted nodes
+   */
+  struct MeshTunnelTreeNode *disconnected_tail;
+
+  /**
+   * Cache of all peers and the first hop to them.
+   * Indexed by PeerIdentity, contains a pointer to the PeerIdentity
+   * of 1st hop.
+   */
+  struct GNUNET_CONTAINER_MultiHashMap *first_hops;
+
+};
+
+
 /**
  * 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.
  */
@@ -42,11 +119,11 @@ path_new (unsigned int length)
 {
   struct MeshPeerPath *p;
 
-  p = GNUNET_malloc (sizeof(struct MeshPeerPath));
+  p = GNUNET_malloc (sizeof (struct MeshPeerPath));
   if (length > 0)
   {
     p->length = length;
-    p->peers = GNUNET_malloc (length * sizeof(GNUNET_PEER_Id));
+    p->peers = GNUNET_malloc (length * sizeof (GNUNET_PEER_Id));
   }
   return p;
 }
@@ -55,7 +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)
@@ -75,7 +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)
@@ -83,62 +160,35 @@ path_duplicate (struct MeshPeerPath *path)
   struct MeshPeerPath *aux;
   unsigned int i;
 
-  aux = path_new(path->length);
-  memcpy (aux->peers, path->peers, path->length * sizeof(GNUNET_PEER_Id));
+  aux = path_new (path->length);
+  memcpy (aux->peers, path->peers, path->length * sizeof (GNUNET_PEER_Id));
   for (i = 0; i < path->length; i++)
-    GNUNET_PEER_change_rc(path->peers[i], 1);
+    GNUNET_PEER_change_rc (path->peers[i], 1);
   return aux;
 }
 
 
 /**
- * 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
+ * Recusively update the info about what is the first hop to reach the node
  *
- * @return peerinfo of the peer who is the first hop in the tunnel
- *         NULL on error
+ * @param tree Tree this nodes belongs to.
+ * @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.
  */
-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->root, peer);
-    if (NULL != t->me && NULL != n)
-    {
-      tree_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;
-}
+static void
+tree_node_update_first_hops (struct MeshTunnelTree *tree,
+                             struct MeshTunnelTreeNode *parent,
+                             struct GNUNET_PeerIdentity *hop);
 
 
 /**
- * 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)
@@ -149,24 +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
  *
@@ -180,7 +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;
 }
@@ -197,140 +229,315 @@ path_destroy (struct MeshPeerPath *p)
  * @return Newly allocated node
  */
 static struct MeshTunnelTreeNode *
-tree_node_new(struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer)
+tree_node_new (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer)
 {
   struct MeshTunnelTreeNode *node;
 
-  node = GNUNET_malloc(sizeof(struct MeshTunnelTreeNode));
+  node = GNUNET_malloc (sizeof (struct MeshTunnelTreeNode));
   node->peer = peer;
-  GNUNET_PEER_change_rc(peer, 1);
+  GNUNET_PEER_change_rc (peer, 1);
   node->parent = parent;
   if (NULL != parent)
-    GNUNET_CONTAINER_DLL_insert(parent->children_head,
-                                parent->children_tail,
-                                node);
+    GNUNET_CONTAINER_DLL_insert (parent->children_head, parent->children_tail,
+                                 node);
 
   return node;
 }
 
 
+/**
+ * Recursively find the given peer.
+ *
+ * @param parent Node where to start looking.
+ * @param peer_id Short ID of the peer to find.
+ *
+ * @return Pointer to the node of the peer. NULL if not found.
+ */
+static struct MeshTunnelTreeNode *
+tree_node_find_peer (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer_id)
+{
+  struct MeshTunnelTreeNode *n;
+  struct MeshTunnelTreeNode *r;
+
+  if (parent->peer == peer_id)
+    return parent;
+  for (n = parent->children_head; NULL != n; n = n->next)
+  {
+    r = tree_node_find_peer (n, peer_id);
+    if (NULL != r)
+      return r;
+  }
+  return NULL;
+}
+
+
+/**
+ * Recusively update the info about what is the first hop to reach the node
+ *
+ * @param tree Tree this nodes belongs to.
+ * @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.
+ */
+static void
+tree_node_update_first_hops (struct MeshTunnelTree *tree,
+                             struct MeshTunnelTreeNode *parent,
+                             struct GNUNET_PeerIdentity *hop)
+{
+  struct GNUNET_PeerIdentity pi;
+  struct GNUNET_PeerIdentity *copy;
+  struct GNUNET_PeerIdentity id;
+  struct MeshTunnelTreeNode *n;
+
+#if MESH_TREE_DEBUG
+  GNUNET_PEER_resolve (parent->peer, &id);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Finding first hop for %s.\n",
+              GNUNET_i2s (&id));
+#endif
+  if (NULL == hop)
+  {
+    struct MeshTunnelTreeNode *aux;
+    struct MeshTunnelTreeNode *old;
+
+    aux = old = parent;
+    while (aux != tree->me)
+    {
+#if MESH_TREE_DEBUG
+      GNUNET_PEER_resolve (aux->peer, &id);
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   ... checking %s.\n",
+                  GNUNET_i2s (&id));
+#endif
+      old = aux;
+      aux = aux->parent;
+      GNUNET_assert (NULL != aux);
+    }
+#if MESH_TREE_DEBUG
+    GNUNET_PEER_resolve (old->peer, &id);
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   It's %s!\n",
+                GNUNET_i2s (&id));
+#endif
+    hop = &pi;
+    GNUNET_PEER_resolve (old->peer, hop);
+  }
+  GNUNET_PEER_resolve (parent->peer, &id);
+  copy = GNUNET_CONTAINER_multihashmap_get (tree->first_hops, &id.hashPubKey);
+  if (NULL == copy)
+    copy = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity));
+  *copy = *hop;
+
+  (void) GNUNET_CONTAINER_multihashmap_put (tree->first_hops, &id.hashPubKey,
+                                            copy,
+                                            GNUNET_CONTAINER_MULTIHASHMAPOPTION_REPLACE);
+
+  for (n = parent->children_head; NULL != n; n = n->next)
+  {
+    tree_node_update_first_hops (tree, n, hop);
+  }
+}
+
+
 static void
-tree_node_debug(struct MeshTunnelTreeNode *n, uint16_t level)
+tree_node_debug (struct MeshTunnelTreeNode *n, uint16_t level)
 {
   struct MeshTunnelTreeNode *c;
   struct GNUNET_PeerIdentity id;;
   uint16_t i;
 
   for (i = 0; i < level; i++)
-    fprintf(stderr, "  ");
+    fprintf (stderr, "  ");
   if (n->status == MESH_PEER_READY)
-    fprintf(stderr, "#");
+    fprintf (stderr, "#");
   if (n->status == MESH_PEER_SEARCHING)
-    fprintf(stderr, "+");
+    fprintf (stderr, "+");
   if (n->status == MESH_PEER_RELAY)
-    fprintf(stderr, "-");
+    fprintf (stderr, "-");
   if (n->status == MESH_PEER_RECONNECTING)
-    fprintf(stderr, "*");
+    fprintf (stderr, "*");
 
-  GNUNET_PEER_resolve(n->peer, &id);
-  fprintf(stderr, "%s, [%u, %p] ", GNUNET_i2s (&id), n->peer, n);
+  GNUNET_PEER_resolve (n->peer, &id);
+  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);
+    GNUNET_PEER_resolve (n->parent->peer, &id);
+    fprintf (stderr, "(-> %s [%u])\n", GNUNET_i2s (&id), n->parent->peer);
   }
   else
-    fprintf(stderr, "(root)\n");
+    fprintf (stderr, "(root)\n");
   for (c = n->children_head; NULL != c; c = c->next)
-    tree_node_debug(c, level + 1);
+    tree_node_debug (c, level + 1);
 }
 
 
 /**
  * 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)
 {
   struct MeshTunnelTreeNode *n;
   struct MeshTunnelTreeNode *next;
+
 #if MESH_TREE_DEBUG
   struct GNUNET_PeerIdentity id;
 
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "tree: Destroying node %u\n",
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree: Destroying node %u\n",
               parent->peer);
   GNUNET_PEER_resolve (parent->peer, &id);
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "tree:   (%s)\n",
-              GNUNET_i2s (&id));
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   (%s)\n", GNUNET_i2s (&id));
 #endif
   n = parent->children_head;
   while (NULL != n)
   {
     next = n->next;
-    tree_node_destroy(n);
+    tree_node_destroy (n);
     n = next;
   }
-  GNUNET_PEER_change_rc(parent->peer, -1);
+  GNUNET_PEER_change_rc (parent->peer, -1);
   if (NULL != parent->parent)
-    GNUNET_CONTAINER_DLL_remove(parent->parent->children_head,
-                                parent->parent->children_tail,
-                                parent);
-  GNUNET_free(parent);
+    GNUNET_CONTAINER_DLL_remove (parent->parent->children_head,
+                                 parent->parent->children_tail, parent);
+  GNUNET_free (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 (struct MeshTunnel *t, GNUNET_PEER_Id peer)
+tree_new (GNUNET_PEER_Id peer)
 {
   struct MeshTunnelTree *tree;
 
-  tree = GNUNET_malloc(sizeof (struct MeshTunnelTree));
-  tree->first_hops = GNUNET_CONTAINER_multihashmap_create(32);
-  tree->root = tree_node_new(NULL, peer);
+  tree = GNUNET_malloc (sizeof (struct MeshTunnelTree));
+  tree->first_hops = GNUNET_CONTAINER_multihashmap_create (32);
+  tree->root = tree_node_new (NULL, peer);
   tree->root->status = MESH_PEER_ROOT;
-  tree->t = t;
-  tree->root->t = t;
+
+  if (1 == peer)
+  {
+    tree->me = tree->root;
+  }
 
   return tree;
 }
 
 
 /**
- * Recursively find the given peer in the tree.
+ * Set the status of a node.
  *
- * @param t Tunnel where to look for the peer.
- * @param peer Peer to find
+ * @param tree Tree.
+ * @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,
+                 enum MeshPeerState status)
+{
+  struct MeshTunnelTreeNode *n;
+
+  n = tree_find_peer (tree, peer);
+  if (NULL == n)
+    return;
+  n->status = status;
+}
+
+
+/**
+ * Get the status of a node.
  *
- * @return Pointer to the node of the peer. NULL if not found.
+ * @param tree Tree whose node's status we want to now.
+ * @param peer A short peer id of the node.
+ *
+ * @return Status of the peer.
  */
-struct MeshTunnelTreeNode *
-tree_find_peer (struct MeshTunnelTreeNode *parent, GNUNET_PEER_Id peer_id)
+enum MeshPeerState
+tree_get_status (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer)
 {
   struct MeshTunnelTreeNode *n;
-  struct MeshTunnelTreeNode *r;
 
-  if (parent->peer == peer_id)
-    return parent;
-  for (n = parent->children_head; NULL != n; n = n->next)
+  n = tree_find_peer (tree, peer);
+  if (NULL == n)
+    return MESH_PEER_INVALID;
+  return n->status;
+}
+
+
+/**
+ * Get the id of the predecessor of the local node.
+ *
+ * @param tree Tree whose local id we want to now.
+ *
+ * @return Short peer id of local peer.
+ */
+GNUNET_PEER_Id
+tree_get_predecessor (struct MeshTunnelTree *tree)
+{
+  if (NULL != tree->me && NULL != tree->me->parent)
+    return tree->me->parent->peer;
+  else
+    return (GNUNET_PEER_Id) 0;
+}
+
+
+/**
+ * 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 *
+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)
   {
-    r = tree_find_peer (n, peer_id);
-    if (NULL != r)
-      return 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 NULL;
+
+  return r;
+}
+
+
+/**
+ * Find the given peer in the tree.
+ *
+ * @param tree Tree where to look for the peer.
+ * @param peer_id Short ID of the peer to find.
+ *
+ * @return Pointer to the node of the peer. NULL if not found.
+ */
+struct MeshTunnelTreeNode *
+tree_find_peer (struct MeshTunnelTree *tree, GNUNET_PEER_Id peer_id)
+{
+  return tree_node_find_peer (tree->root, peer_id);
 }
 
 
@@ -340,11 +547,12 @@ tree_find_peer (struct MeshTunnelTreeNode *parent, 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,
                               struct MeshTunnelTreeNode *parent,
-                              MeshNodeDisconnectCB cb)
+                              MeshTreeCallback cb, void *cbcls)
 {
   struct GNUNET_PeerIdentity *pi;
   struct GNUNET_PeerIdentity id;
@@ -352,110 +560,81 @@ tree_mark_peers_disconnected (struct MeshTunnelTree *tree,
 
   for (n = parent->children_head; NULL != n; n = n->next)
   {
-    tree_mark_peers_disconnected (tree, n, cb);
+    tree_mark_peers_disconnected (tree, n, cb, cbcls);
   }
   if (MESH_PEER_READY == parent->status)
   {
     if (NULL != cb)
-      cb (parent);
+      cb (cbcls, parent->peer);
     parent->status = MESH_PEER_RECONNECTING;
   }
 
   /* Remove and free info about first hop */
-  GNUNET_PEER_resolve(parent->peer, &id);
-  pi = GNUNET_CONTAINER_multihashmap_get(tree->first_hops, &id.hashPubKey);
-  GNUNET_CONTAINER_multihashmap_remove_all(tree->first_hops, &id.hashPubKey);
+  GNUNET_PEER_resolve (parent->peer, &id);
+  pi = GNUNET_CONTAINER_multihashmap_get (tree->first_hops, &id.hashPubKey);
+  GNUNET_CONTAINER_multihashmap_remove_all (tree->first_hops, &id.hashPubKey);
   if (NULL != pi)
-    GNUNET_free(pi);
+    GNUNET_free (pi);
 }
 
 
 /**
- * Recusively update the info about what is the first hop to reach the node
+ * Iterate over all children of the local node.
  *
- * @param tree Tree this nodes belongs to
- * @param parent Node to be start updating
- * @param hop If known, ID of the first hop.
- *            If not known, NULL to find out and pass on children.
+ * @param tree Tree to use. Must have "me" set.
+ * @param cb Callback to call over each child.
+ * @param cls Closure.
  */
 void
-tree_update_first_hops (struct MeshTunnelTree *tree,
-                        struct MeshTunnelTreeNode *parent,
-                        struct GNUNET_PeerIdentity *hop)
+tree_iterate_children (struct MeshTunnelTree *tree, MeshTreeCallback cb,
+                       void *cls)
 {
-  struct GNUNET_PeerIdentity pi;
-  struct GNUNET_PeerIdentity *copy;
-  struct GNUNET_PeerIdentity id;
   struct MeshTunnelTreeNode *n;
 
-#if MESH_TREE_DEBUG
-  GNUNET_PEER_resolve(parent->peer, &id);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-          "tree:   Finding first hop for %s.\n",
-          GNUNET_i2s (&id));
-#endif
-  if (NULL == hop)
+  if (NULL == tree->me)
   {
-    struct MeshTunnelTreeNode *aux;
-    struct MeshTunnelTreeNode *old;
-
-    aux = old = parent;
-    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_i2s (&id));
-#endif
-      old = aux;
-      aux = aux->parent;
-      GNUNET_assert(NULL != aux);
-    }
-#if MESH_TREE_DEBUG
-    GNUNET_PEER_resolve(old->peer, &id);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-               "tree:   It's %s!\n",
-               GNUNET_i2s (&id));
-#endif
-    hop = &pi;
-    GNUNET_PEER_resolve(old->peer, hop);
+    GNUNET_break (0);
+    return;
   }
-  GNUNET_PEER_resolve(parent->peer, &id);
-  copy = GNUNET_CONTAINER_multihashmap_get (tree->first_hops, &id.hashPubKey);
-  if (NULL == copy)
-    copy = GNUNET_malloc(sizeof(struct GNUNET_PeerIdentity));
-  *copy = *hop;
-
-  (void) GNUNET_CONTAINER_multihashmap_put(
-    tree->first_hops,
-    &id.hashPubKey,
-    copy,
-    GNUNET_CONTAINER_MULTIHASHMAPOPTION_REPLACE);
-
-  for (n = parent->children_head; NULL != n; n = n->next)
+  for (n = tree->me->children_head; NULL != n; n = n->next)
   {
-    tree_update_first_hops (tree, n, hop);
+    cb (cls, n->peer);
   }
 }
 
 
+/**
+ * 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 hop If known, ID of the first hop.
+ *            If not known, NULL to find out and pass on children.
+ */
+void
+tree_update_first_hops (struct MeshTunnelTree *tree, GNUNET_PEER_Id parent_id,
+                        struct GNUNET_PeerIdentity *hop)
+{
+  tree_node_update_first_hops (tree, tree_find_peer (tree, parent_id), hop);
+}
+
+
 /**
  * Delete the current path to the peer, including all now unused relays.
  * The destination peer is NOT destroyed, it is returned in order to either set
  * 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.
  *
  * @return pointer to the pathless node.
  *         NULL when not found
  */
 struct MeshTunnelTreeNode *
-tree_del_path (struct MeshTunnelTree *t,
-               GNUNET_PEER_Id peer_id,
-               MeshNodeDisconnectCB cb)
+tree_del_path (struct MeshTunnelTree *t, GNUNET_PEER_Id peer_id,
+               MeshTreeCallback cb, void *cbcls)
 {
   struct MeshTunnelTreeNode *parent;
   struct MeshTunnelTreeNode *node;
@@ -463,10 +642,10 @@ tree_del_path (struct MeshTunnelTree *t,
 
 #if MESH_TREE_DEBUG
   struct GNUNET_PeerIdentity id;
-  GNUNET_PEER_resolve(peer_id, &id);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-          "tree:   Deleting path to %s.\n",
-          GNUNET_i2s (&id));
+
+  GNUNET_PEER_resolve (peer_id, &id);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Deleting path to %s.\n",
+              GNUNET_i2s (&id));
 #endif
   if (peer_id == t->root->peer)
     return NULL;
@@ -476,41 +655,38 @@ tree_del_path (struct MeshTunnelTree *t,
     if (n->peer == peer_id)
     {
       /* Was already pathless, waiting for reconnection */
-      GNUNET_CONTAINER_DLL_remove (t->disconnected_head,
-                                   t->disconnected_tail,
+      GNUNET_CONTAINER_DLL_remove (t->disconnected_head, t->disconnected_tail,
                                    n);
       return n;
     }
   }
-  n = tree_find_peer (t->root, peer_id);
+  n = tree_find_peer (t, peer_id);
   if (NULL == n)
     return NULL;
   node = n;
 
   parent = n->parent;
-  GNUNET_CONTAINER_DLL_remove(parent->children_head, parent->children_tail, n);
+  GNUNET_CONTAINER_DLL_remove (parent->children_head, parent->children_tail, n);
   n->parent = NULL;
 
   while (MESH_PEER_RELAY == parent->status && NULL == parent->children_head)
   {
 #if MESH_TREE_DEBUG
-    GNUNET_PEER_resolve(parent->peer, &id);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-              "tree:   Deleting node %s.\n",
-              GNUNET_i2s (&id));
+    GNUNET_PEER_resolve (parent->peer, &id);
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Deleting node %s.\n",
+                GNUNET_i2s (&id));
 #endif
     n = parent->parent;
-    tree_node_destroy(parent);
+    tree_node_destroy (parent);
     parent = n;
   }
 #if MESH_TREE_DEBUG
-  GNUNET_PEER_resolve(parent->peer, &id);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-             "tree:   Not deleted peer %s.\n",
-             GNUNET_i2s (&id));
+  GNUNET_PEER_resolve (parent->peer, &id);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Not deleted peer %s.\n",
+              GNUNET_i2s (&id));
 #endif
 
-  tree_mark_peers_disconnected (t, node, cb);
+  tree_mark_peers_disconnected (t, node, cb, cbcls);
 
   return node;
 }
@@ -520,36 +696,43 @@ tree_del_path (struct MeshTunnelTree *t,
  * 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.
  */
 struct MeshPeerPath *
-tree_get_path_to_peer(struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
+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->me, peer);
+  n = tree_find_peer (t, peer);
   if (NULL == n)
+  {
+    GNUNET_break (0);
     return NULL;
-  p = path_new(0);
+  }
+  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);
+    GNUNET_array_append (p->peers, p->length, n->peer);
+    GNUNET_PEER_change_rc (n->peer, 1);
     n = n->parent;
-    GNUNET_assert(NULL != n);
+    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);
+  path_invert (p);
 
   return p;
 }
@@ -567,7 +750,8 @@ tree_get_path_to_peer(struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
  *
  * @param t Tunnel where to add the new path.
  * @param p Path to be integrated.
- * @param cb Callback to use to notify about peers temporarily disconnecting
+ * @param cb Callback to use to notify about peers temporarily disconnecting.
+ * @param cbcls Closure for cb.
  *
  * @return GNUNET_OK in case of success.
  *         GNUNET_SYSERR in case of error.
@@ -577,32 +761,25 @@ tree_get_path_to_peer(struct MeshTunnelTree *t, GNUNET_PEER_Id peer)
  * - do not disconnect peers until new path is created & connected
  */
 int
-tree_add_path (struct MeshTunnelTree *t,
-               const struct MeshPeerPath *p,
-               MeshNodeDisconnectCB cb)
+tree_add_path (struct MeshTunnelTree *t, const struct MeshPeerPath *p,
+               MeshTreeCallback cb, void *cbcls)
 {
   struct MeshTunnelTreeNode *parent;
   struct MeshTunnelTreeNode *oldnode;
   struct MeshTunnelTreeNode *n;
   struct MeshTunnelTreeNode *c;
   struct GNUNET_PeerIdentity id;
-  GNUNET_PEER_Id myid;
   int me;
   unsigned int i;
 
 #if MESH_TREE_DEBUG
-  GNUNET_PEER_resolve(p->peers[p->length - 1], &id);
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-             "tree:   Adding path [%u] towards peer %s.\n",
-            p->length,
-            GNUNET_i2s (&id));
+  GNUNET_PEER_resolve (p->peers[p->length - 1], &id);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "tree:   Adding path [%u] towards peer %s.\n", p->length,
+              GNUNET_i2s (&id));
 #endif
 
-  if (NULL != t->me)
-    myid = t->me->peer;
-  else
-    myid = 0;
-  GNUNET_assert(0 != p->length);
+  GNUNET_assert (0 != p->length);
   parent = n = t->root;
   if (n->peer != p->peers[0])
   {
@@ -611,34 +788,32 @@ tree_add_path (struct MeshTunnelTree *t,
   }
   if (1 == p->length)
     return GNUNET_OK;
-  oldnode = tree_del_path (t, p->peers[p->length - 1], cb);
+  oldnode = tree_del_path (t, p->peers[p->length - 1], cb, cbcls);
   /* Look for the first node that is not already present in the tree
    *
    * Assuming that the tree is somewhat balanced, O(log n * log N).
    * - 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
-    GNUNET_PEER_resolve(p->peers[i], &id);
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-               "tree:   Looking for peer %s.\n",
-               GNUNET_i2s (&id));
+    GNUNET_PEER_resolve (p->peers[i], &id);
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Looking for peer %s.\n",
+                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)
     {
       if (c->peer == p->peers[i])
       {
 #if MESH_TREE_DEBUG
-        GNUNET_PEER_resolve(parent->peer, &id);
-        GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-                   "tree:   Found in children of %s.\n",
-                   GNUNET_i2s (&id));
+        GNUNET_PEER_resolve (parent->peer, &id);
+        GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                    "tree:   Found in children of %s.\n", GNUNET_i2s (&id));
 #endif
         n = c;
         break;
@@ -650,71 +825,76 @@ tree_add_path (struct MeshTunnelTree *t,
       break;
   }
 #if MESH_TREE_DEBUG
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-             "tree:   All childen visited.\n");
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   All childen visited.\n");
 #endif
   /* Add the rest of the path as a branch from parent. */
   while (i < p->length)
   {
 #if MESH_TREE_DEBUG
-    GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-               "tree:   Adding peer %u to %u.\n",
-               p->peers[i], parent->peer);
-    GNUNET_PEER_resolve(p->peers[i], &id);
-    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_i2s (&id));
+    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Adding peer %u to %u.\n",
+                p->peers[i], parent->peer);
+    GNUNET_PEER_resolve (p->peers[i], &id);
+    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_i2s (&id));
 #endif
 
     if (i == p->length - 1 && NULL != oldnode)
     {
 #if MESH_TREE_DEBUG
-      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
-                 "tree:   Putting old node into place.\n");
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "tree:   Putting old node into place.\n");
 #endif
       oldnode->parent = parent;
-      GNUNET_CONTAINER_DLL_insert(parent->children_head,
-                                  parent->children_tail,
-                                  oldnode);
-      tree_update_first_hops (t, oldnode, NULL);
+      GNUNET_CONTAINER_DLL_insert (parent->children_head, parent->children_tail,
+                                   oldnode);
+      tree_node_update_first_hops (t, oldnode, NULL);
       n = oldnode;
     }
     else
     {
 #if MESH_TREE_DEBUG
-      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "tree:   Creating new node.\n");
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree:   Creating new node.\n");
 #endif
-      n = tree_node_new(parent, p->peers[i]);
-      n->t = t->t;
+      n = tree_node_new (parent, p->peers[i]);
       n->status = MESH_PEER_RELAY;
-      if (n->peer == myid)
+      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)
   {
 #if MESH_TREE_DEBUG
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-                "MESH:   finding first hop (own pos %d/%u)\n",
-                me, p->length - 1);
+                "MESH:   finding first hop (own pos %d/%u)\n", me,
+                p->length - 1);
 #endif
     GNUNET_PEER_resolve (p->peers[me + 1], &id);
-    tree_update_first_hops(t,
-                           tree_find_peer(t->root, p->peers[p->length - 1]),
-                           &id);
+    tree_update_first_hops (t, p->peers[me + 1], &id);
   }
 #if MESH_TREE_DEBUG
-  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "tree:   New node added.\n");
+  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;
 }
 
@@ -727,43 +907,37 @@ tree_add_path (struct MeshTunnelTree *t,
  * @param p1 Short id of one of the peers (order unimportant)
  * @param p2 Short id of one of the peers (order unimportant)
  * @param cb Function to call for every peer that is marked as disconnected.
+ * @param cbcls Closure for cb.
  *
  * @return Short ID of the first disconnected peer in the tree.
  */
 GNUNET_PEER_Id
-tree_notify_connection_broken (struct MeshTunnelTree *t,
-                               GNUNET_PEER_Id p1,
-                               GNUNET_PEER_Id p2,
-                               MeshNodeDisconnectCB cb)
+tree_notify_connection_broken (struct MeshTunnelTree *t, GNUNET_PEER_Id p1,
+                               GNUNET_PEER_Id p2, MeshTreeCallback cb,
+                               void *cbcls)
 {
   struct MeshTunnelTreeNode *n;
   struct MeshTunnelTreeNode *c;
 
-  n = tree_find_peer(t->me, p1);
+  n = tree_find_peer (t, p1);
   if (NULL == n)
     return 0;
   if (NULL != n->parent && n->parent->peer == p2)
   {
-    tree_mark_peers_disconnected(t, n, cb);
-    GNUNET_CONTAINER_DLL_remove(n->parent->children_head,
-                                n->parent->children_tail,
-                                n);
-    GNUNET_CONTAINER_DLL_insert(t->disconnected_head,
-                                t->disconnected_tail,
-                                n);
+    tree_mark_peers_disconnected (t, n, cb, cbcls);
+    GNUNET_CONTAINER_DLL_remove (n->parent->children_head,
+                                 n->parent->children_tail, n);
+    GNUNET_CONTAINER_DLL_insert (t->disconnected_head, t->disconnected_tail, n);
     return p1;
   }
   for (c = n->children_head; NULL != c; c = c->next)
   {
     if (c->peer == p2)
     {
-      tree_mark_peers_disconnected(t, c, cb);
-      GNUNET_CONTAINER_DLL_remove(n->children_head,
-                                  n->children_tail,
-                                  c);
-      GNUNET_CONTAINER_DLL_insert(t->disconnected_head,
-                                  t->disconnected_tail,
-                                  c);
+      tree_mark_peers_disconnected (t, c, cb, cbcls);
+      GNUNET_CONTAINER_DLL_remove (n->children_head, n->children_tail, c);
+      GNUNET_CONTAINER_DLL_insert (t->disconnected_head, t->disconnected_tail,
+                                   c);
       return p2;
     }
   }
@@ -780,27 +954,77 @@ tree_notify_connection_broken (struct MeshTunnelTree *t,
  * @param t Tunnel tree to use.
  * @param peer Short ID of the peer to remove from the tunnel tree.
  * @param cb Callback to notify client of disconnected peers.
+ * @param cbcls Closure for cb.
  *
  * @return GNUNET_OK or GNUNET_SYSERR
  */
 int
-tree_del_peer (struct MeshTunnelTree *t,
-               GNUNET_PEER_Id peer,
-               MeshNodeDisconnectCB cb)
+tree_del_peer (struct MeshTunnelTree *t, GNUNET_PEER_Id peer,
+               MeshTreeCallback cb, void *cbcls)
 {
   struct MeshTunnelTreeNode *n;
 
-  n = tree_del_path(t, peer, cb);
+  n = tree_del_path (t, peer, cb, cbcls);
   if (NULL == n)
-    return GNUNET_SYSERR;
+  {
+    GNUNET_break (0);
+    return GNUNET_YES;
+  }
   GNUNET_break_op (NULL == n->children_head);
-  tree_node_destroy(n);
+  tree_node_destroy (n);
   if (NULL == t->root->children_head && t->me != t->root)
   {
     tree_node_destroy (t->root);
     t->root = NULL;
+    return GNUNET_NO;
   }
-  return GNUNET_OK;
+  return GNUNET_YES;
+}
+
+
+
+/**
+ * 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;
 }
 
 
@@ -810,9 +1034,9 @@ tree_del_peer (struct MeshTunnelTree *t,
  * @param t The tree
  */
 void
-tree_debug(struct MeshTunnelTree *t)
+tree_debug (struct MeshTunnelTree *t)
 {
-  tree_node_debug(t->root, 0);
+  tree_node_debug (t->root, 0);
 }
 
 
@@ -828,14 +1052,14 @@ tree_debug(struct MeshTunnelTree *t)
 static int
 iterate_free (void *cls, const GNUNET_HashCode * key, void *value)
 {
-  GNUNET_free(value);
+  GNUNET_free (value);
   return GNUNET_YES;
 }
 
 
 /**
  * Destroy the whole tree and free all used memory and Peer_Ids
- * 
+ *
  * @param t Tree to be destroyed
  */
 void
@@ -844,8 +1068,8 @@ tree_destroy (struct MeshTunnelTree *t)
 #if MESH_TREE_DEBUG
   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "tree: Destroying tree\n");
 #endif
-  tree_node_destroy(t->root);
-  GNUNET_CONTAINER_multihashmap_iterate(t->first_hops, &iterate_free, NULL);
-  GNUNET_CONTAINER_multihashmap_destroy(t->first_hops);
-  GNUNET_free(t);
+  tree_node_destroy (t->root);
+  GNUNET_CONTAINER_multihashmap_iterate (t->first_hops, &iterate_free, NULL);
+  GNUNET_CONTAINER_multihashmap_destroy (t->first_hops);
+  GNUNET_free (t);
 }