X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fmesh%2Fgnunet-service-mesh_tunnel.c;h=231eeabebb97d1a2941b24bd6946ba7c020184d4;hb=1ef7f26b7579ae2a6256751a3f5ebfbf60afbb2f;hp=e709a0be544e2c4d58153a3d4c9f6943b61de418;hpb=dcba7f93f6cbccbd5f103675109fb1ebb88d6b41;p=oweals%2Fgnunet.git

diff --git a/src/mesh/gnunet-service-mesh_tunnel.c b/src/mesh/gnunet-service-mesh_tunnel.c
index e709a0be5..231eeabeb 100644
--- a/src/mesh/gnunet-service-mesh_tunnel.c
+++ b/src/mesh/gnunet-service-mesh_tunnel.c
@@ -33,6 +33,9 @@
 
 #define LOG(level, ...) GNUNET_log_from(level,"mesh-tun",__VA_ARGS__)
 
+#define START_FUNCTION LOG(GNUNET_ERROR_TYPE_DEBUG, "%s start\n", __FUNCTION__)
+#define END_FUNCTION LOG(GNUNET_ERROR_TYPE_DEBUG, "%s end\n", __FUNCTION__)
+
 
 /******************************************************************************/
 /********************************   STRUCTS  **********************************/
@@ -65,22 +68,22 @@ struct MeshTunnel3
     /**
      * State of the tunnel.
      */
-  enum MeshTunnelState state;
+  enum MeshTunnel3State state;
 
   /**
    * Local peer ephemeral private key
    */
-  struct GNUNET_CRYPTO_EccPrivateKey *my_eph_key;
+  struct GNUNET_CRYPTO_EddsaPrivateKey *my_eph_key;
 
   /**
    * Local peer ephemeral public key
    */
-  struct GNUNET_CRYPTO_EccPublicSignKey *my_eph;
+  struct GNUNET_CRYPTO_EddsaPublicKey *my_eph;
 
   /**
    * Remote peer's public key.
    */
-  struct GNUNET_CRYPTO_EccPublicSignKey *peers_eph;
+  struct GNUNET_CRYPTO_EddsaPublicKey *peers_eph;
 
   /**
    * Encryption ("our") key.
@@ -114,11 +117,6 @@ struct MeshTunnel3
    */
   MESH_ChannelNumber next_chid;
 
-  /**
-   * Channel ID for the next incoming channel.
-   */
-  MESH_ChannelNumber next_local_chid;
-
   /**
    * Pending message count.
    */
@@ -169,24 +167,24 @@ struct MeshTunnelQueue
 extern struct GNUNET_STATISTICS_Handle *stats;
 
 /**
- * Default TTL for payload packets.
+ * Local peer own ID (memory efficient handle).
  */
-static unsigned long long default_ttl;
+extern GNUNET_PEER_Id myid;
 
 /**
- * Local peer own ID (memory efficient handle).
+ * Local peer own ID (full value).
  */
-static GNUNET_PEER_Id my_short_id;
+extern struct GNUNET_PeerIdentity my_full_id;
 
 /**
- * Local peer own ID (full value).
+ * Default TTL for payload packets.
  */
-const static struct GNUNET_PeerIdentity *my_full_id;
+static unsigned long long default_ttl;
 
 /**
  * Own private key.
  */
-const static struct GNUNET_CRYPTO_EccPrivateKey *my_private_key;
+const static struct GNUNET_CRYPTO_EddsaPrivateKey *my_private_key;
 
 
 /******************************************************************************/
@@ -201,22 +199,22 @@ const static struct GNUNET_CRYPTO_EccPrivateKey *my_private_key;
  * @return String representation.
  */
 static const char *
-GMT_state2s (enum MeshTunnelState s)
+GMT_state2s (enum MeshTunnel3State s)
 {
   static char buf[128];
 
   switch (s)
   {
-    case MESH_TUNNEL_NEW:
-      return "MESH_TUNNEL_NEW";
-    case MESH_TUNNEL_SEARCHING:
-      return "MESH_TUNNEL_SEARCHING";
-    case MESH_TUNNEL_WAITING:
-      return "MESH_TUNNEL_WAITING";
-    case MESH_TUNNEL_READY:
-      return "MESH_TUNNEL_READY";
-    case MESH_TUNNEL_RECONNECTING:
-      return "MESH_TUNNEL_RECONNECTING";
+    case MESH_TUNNEL3_NEW:
+      return "MESH_TUNNEL3_NEW";
+    case MESH_TUNNEL3_SEARCHING:
+      return "MESH_TUNNEL3_SEARCHING";
+    case MESH_TUNNEL3_WAITING:
+      return "MESH_TUNNEL3_WAITING";
+    case MESH_TUNNEL3_READY:
+      return "MESH_TUNNEL3_READY";
+    case MESH_TUNNEL3_RECONNECTING:
+      return "MESH_TUNNEL3_RECONNECTING";
 
     default:
       sprintf (buf, "%u (UNKNOWN STATE)", s);
@@ -224,33 +222,6 @@ GMT_state2s (enum MeshTunnelState s)
   }
 }
 
-
-/**
- * Search for a channel by global ID using full PeerIdentities.
- *
- * @param t Tunnel containing the channel.
- * @param chid Public channel number.
- *
- * @return channel handler, NULL if doesn't exist
- */
-static struct MeshChannel *
-get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
-{
-  struct MeshTChannel *iter;
-
-  if (NULL == t)
-    return NULL;
-
-  for (iter = t->channel_head; NULL != iter; iter = iter->next)
-  {
-    if (GMCH_get_id (iter->ch) == chid)
-      break;
-  }
-
-  return NULL == iter ? NULL : iter->ch;
-}
-
-
 /**
  * Pick a connection on which send the next data message.
  *
@@ -289,6 +260,46 @@ tunnel_get_connection (struct MeshTunnel3 *t, int fwd)
 }
 
 
+/**
+ * FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
+ * Encrypt data with the tunnel key.
+ *
+ * @param t Tunnel whose key to use.
+ * @param dst Destination for the GMT_encrypted data.
+ * @param src Source of the plaintext.
+ * @param size Size of the plaintext.
+ * @param iv Initialization Vector to use.
+ * @param fwd Is this a fwd message?
+ */
+static void
+GMT_encrypt (struct MeshTunnel3 *t,
+             void *dst, const void *src,
+             size_t size, uint64_t iv, int fwd)
+{
+  memcpy (dst, src, size);
+}
+
+
+/**
+ * FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
+ * Decrypt data with the tunnel key.
+ *
+ * @param t Tunnel whose key to use.
+ * @param dst Destination for the plaintext.
+ * @param src Source of the GMT_encrypted data.
+ * @param size Size of the GMT_encrypted data.
+ * @param iv Initialization Vector to use.
+ * @param fwd Is this a fwd message?
+ */
+static void
+GMT_decrypt (struct MeshTunnel3 *t,
+             void *dst, const void *src,
+             size_t size, uint64_t iv, int fwd)
+{
+  memcpy (dst, src, size);
+}
+
+
 void
 handle_data (struct MeshTunnel3 *t,
              const struct GNUNET_MESH_Data *msg,
@@ -314,7 +325,7 @@ handle_data (struct MeshTunnel3 *t,
               GNUNET_MESH_DEBUG_M2S (ntohs (msg[1].header.type)));
 
   /* Check channel */
-  ch = get_channel (t, ntohl (msg->chid));
+  ch = GMT_get_channel (t, ntohl (msg->chid));
   if (NULL == ch)
   {
     GNUNET_STATISTICS_update (stats, "# data on unknown channel",
@@ -324,7 +335,7 @@ handle_data (struct MeshTunnel3 *t,
     return;
   }
 
-  GMT_change_state (t, MESH_TUNNEL_READY);
+  GMT_change_state (t, MESH_TUNNEL3_READY);
   GMCH_handle_data (ch, msg, fwd);
 }
 
@@ -345,7 +356,7 @@ handle_data_ack (struct MeshTunnel3 *t,
   }
 
   /* Check channel */
-  ch = get_channel (t, ntohl (msg->chid));
+  ch = GMT_get_channel (t, ntohl (msg->chid));
   if (NULL == ch)
   {
     GNUNET_STATISTICS_update (stats, "# data ack on unknown channel",
@@ -363,6 +374,8 @@ handle_ch_create (struct MeshTunnel3 *t,
                   const struct GNUNET_MESH_ChannelCreate *msg,
                   int fwd)
 {
+  ;
+
   struct MeshTChannel *tch;
   struct MeshChannel *ch;
   size_t size;
@@ -376,7 +389,7 @@ handle_ch_create (struct MeshTunnel3 *t,
   }
 
   /* Check channel */
-  ch = get_channel (t, ntohl (msg->chid));
+  ch = GMT_get_channel (t, ntohl (msg->chid));
   if (NULL != ch)
   {
     /* Probably a retransmission, safe to ignore */
@@ -384,12 +397,14 @@ handle_ch_create (struct MeshTunnel3 *t,
   }
   else
   {
-    ch = GMCH_handle_create (msg, fwd);
+    ch = GMCH_handle_create (t, msg, fwd);
   }
 
   tch = GNUNET_new (struct MeshTChannel);
   tch->ch = ch;
   GNUNET_CONTAINER_DLL_insert (t->channel_head, t->channel_tail, tch);
+
+  ;
 }
 
 void
@@ -409,7 +424,7 @@ handle_ch_ack (struct MeshTunnel3 *t,
   }
 
   /* Check channel */
-  ch = get_channel (t, ntohl (msg->chid));
+  ch = GMT_get_channel (t, ntohl (msg->chid));
   if (NULL == ch)
   {
     GNUNET_STATISTICS_update (stats, "# channel ack on unknown channel",
@@ -439,7 +454,7 @@ handle_ch_destroy (struct MeshTunnel3 *t,
   }
 
   /* Check channel */
-  ch = get_channel (t, ntohl (msg->chid));
+  ch = GMT_get_channel (t, ntohl (msg->chid));
   if (NULL == ch)
   {
     /* Probably a retransmission, safe to ignore */
@@ -449,9 +464,6 @@ handle_ch_destroy (struct MeshTunnel3 *t,
   GMCH_handle_destroy (ch, msg, fwd);
 }
 
-/******************************************************************************/
-/********************************    API    ***********************************/
-/******************************************************************************/
 
 /**
  * Demultiplex by message type and call appropriate handler for a message
@@ -461,10 +473,10 @@ handle_ch_destroy (struct MeshTunnel3 *t,
  * @param msgh Message header.
  * @param fwd Is this message fwd?
  */
-void
-GMT_handle_decrypted (struct MeshTunnel3 *t,
-                      const struct GNUNET_MessageHeader *msgh,
-                      int fwd)
+static void
+handle_decrypted (struct MeshTunnel3 *t,
+                  const struct GNUNET_MessageHeader *msgh,
+                  int fwd)
 {
   uint16_t type;
 
@@ -510,6 +522,40 @@ GMT_handle_decrypted (struct MeshTunnel3 *t,
   }
 }
 
+/******************************************************************************/
+/********************************    API    ***********************************/
+/******************************************************************************/
+
+
+/**
+ * Decrypt and demultiplex by message type. Call appropriate handler
+ * for every message.
+ *
+ * @param t Tunnel this message came on.
+ * @param msg Encrypted message.
+ * @param fwd Is this message fwd?
+ */
+void
+GMT_handle_encrypted (struct MeshTunnel3 *t,
+                      const struct GNUNET_MESH_Encrypted *msg,
+                      int fwd)
+{
+  size_t size = ntohs (msg->header.size);
+  size_t payload_size = size - sizeof (struct GNUNET_MESH_Encrypted);
+  char cbuf[payload_size];
+  struct GNUNET_MessageHeader *msgh;
+  unsigned int off;
+
+  GMT_decrypt (t, cbuf, &msg[1], payload_size, msg->iv, fwd);
+  off = 0;
+  while (off < payload_size)
+  {
+    msgh = (struct GNUNET_MessageHeader *) &cbuf[off];
+        handle_decrypted (t, msgh, fwd);
+    off += ntohs (msgh->size);
+  }
+}
+
 
 /**
  * Cache a message to be sent once tunnel is online.
@@ -534,7 +580,7 @@ GMT_queue_data (struct MeshTunnel3 *t,
   memcpy (&tq[1], msg, size);
   GNUNET_CONTAINER_DLL_insert_tail (t->tq_head, t->tq_tail, tq);
 
-  if (MESH_TUNNEL_READY == t->state)
+  if (MESH_TUNNEL3_READY == t->state)
     GMT_send_queued_data (t, fwd);
 }
 
@@ -554,11 +600,12 @@ GMT_send_queued_data (struct MeshTunnel3 *t, int fwd)
 
   LOG (GNUNET_ERROR_TYPE_DEBUG,
               "GMT_send_queued_data on tunnel %s\n",
-              GMP_2s (t->peer));
+              GMT_2s (t));
   room = GMT_get_buffer (t, fwd);
   LOG (GNUNET_ERROR_TYPE_DEBUG, "  buffer space: %u\n", room);
   for (tq = t->tq_head; NULL != tq && room > 0; tq = next)
   {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, " data on channel %s\n", GMCH_2s (tq->ch));
     next = tq->next;
     room--;
     GNUNET_CONTAINER_DLL_remove (t->tq_head, t->tq_tail, tq);
@@ -567,6 +614,9 @@ GMT_send_queued_data (struct MeshTunnel3 *t, int fwd)
 
     GNUNET_free (tq);
   }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "GMT_send_queued_data end\n",
+       GMP_2s (t->peer));
 }
 
 
@@ -579,9 +629,9 @@ GMT_send_queued_data (struct MeshTunnel3 *t, int fwd)
  */
 void
 GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
-          const struct GNUNET_PeerIdentity *id,
-          const struct GNUNET_CRYPTO_EccPrivateKey *key)
+          const struct GNUNET_CRYPTO_EddsaPrivateKey *key)
 {
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "init\n");
   if (GNUNET_OK !=
       GNUNET_CONFIGURATION_get_value_number (c, "MESH", "DEFAULT_TTL",
                                              &default_ttl))
@@ -590,9 +640,7 @@ GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
                                "MESH", "DEFAULT_TTL", "USING DEFAULT");
     default_ttl = 64;
   }
-  my_full_id = id;
   my_private_key = key;
-  my_short_id = GNUNET_PEER_intern (my_full_id);
 }
 
 
@@ -602,21 +650,22 @@ GMT_init (const struct GNUNET_CONFIGURATION_Handle *c,
 void
 GMT_shutdown (void)
 {
-  GNUNET_PEER_change_rc (my_short_id, -1);
 }
 
 
 /**
  * Create a tunnel.
+ *
+ * @param destination Peer this tunnel is towards.
  */
 struct MeshTunnel3 *
-GMT_new (void)
+GMT_new (struct MeshPeer *destination)
 {
   struct MeshTunnel3 *t;
 
   t = GNUNET_new (struct MeshTunnel3);
   t->next_chid = 0;
-  t->next_local_chid = GNUNET_MESH_LOCAL_CHANNEL_ID_SERV;
+  t->peer = destination;
 //   if (GNUNET_OK !=
 //       GNUNET_CONTAINER_multihashmap_put (tunnels, tid, t,
 //                                          GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
@@ -644,7 +693,6 @@ GMT_new (void)
 }
 
 
-
 /**
  * Change the tunnel state.
  *
@@ -652,7 +700,7 @@ GMT_new (void)
  * @param state New state.
  */
 void
-GMT_change_state (struct MeshTunnel3* t, enum MeshTunnelState state)
+GMT_change_state (struct MeshTunnel3* t, enum MeshTunnel3State state)
 {
   if (NULL == t)
     return;
@@ -665,6 +713,10 @@ GMT_change_state (struct MeshTunnel3* t, enum MeshTunnelState state)
               GMP_2s (t->peer),
               GMT_state2s (state));
   t->state = state;
+  if (MESH_TUNNEL3_READY == state && 3 <= GMT_count_connections (t))
+  {
+    GMP_stop_search (t->peer);
+  }
 }
 
 
@@ -710,6 +762,74 @@ GMT_remove_connection (struct MeshTunnel3 *t, struct MeshConnection *c)
 }
 
 
+/**
+ * Add a channel to a tunnel.
+ *
+ * @param t Tunnel.
+ * @param ch Channel.
+ */
+void
+GMT_add_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
+{
+  struct MeshTChannel *aux;
+
+  for (aux = t->channel_head; aux != NULL; aux = aux->next)
+    if (aux->ch == ch)
+      return;
+
+  aux = GNUNET_new (struct MeshTChannel);
+  aux->ch = ch;
+  GNUNET_CONTAINER_DLL_insert_tail (t->channel_head, t->channel_tail, aux);
+}
+
+
+/**
+ * Remove a channel from a tunnel.
+ *
+ * @param t Tunnel.
+ * @param ch Channel.
+ */
+void
+GMT_remove_channel (struct MeshTunnel3 *t, struct MeshChannel *ch)
+{
+  struct MeshTChannel *aux;
+
+  for (aux = t->channel_head; aux != NULL; aux = aux->next)
+    if (aux->ch == ch)
+    {
+      GNUNET_CONTAINER_DLL_remove (t->channel_head, t->channel_tail, aux);
+      GNUNET_free (aux);
+      return;
+    }
+}
+
+
+/**
+ * Search for a channel by global ID.
+ *
+ * @param t Tunnel containing the channel.
+ * @param chid Public channel number.
+ *
+ * @return channel handler, NULL if doesn't exist
+ */
+struct MeshChannel *
+GMT_get_channel (struct MeshTunnel3 *t, MESH_ChannelNumber chid)
+{
+  struct MeshTChannel *iter;
+
+  if (NULL == t)
+    return NULL;
+
+  for (iter = t->channel_head; NULL != iter; iter = iter->next)
+  {
+    if (GMCH_get_id (iter->ch) == chid)
+      break;
+  }
+
+  return NULL == iter ? NULL : iter->ch;
+}
+
+
 /**
  * Tunnel is empty: destroy it.
  *
@@ -788,48 +908,6 @@ GMT_destroy (struct MeshTunnel3 *t)
 }
 
 
-/**
- * Notifies a tunnel that a connection has broken that affects at least
- * some of its peers. Sends a notification towards the root of the tree.
- * In case the peer is the owner of the tree, notifies the client that owns
- * the tunnel and tries to reconnect.
- *
- * FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
- *
- * @param t Tunnel affected.
- * @param p1 Peer that got disconnected from p2.
- * @param p2 Peer that got disconnected from p1.
- *
- * @return Short ID of the peer disconnected (either p1 or p2).
- *         0 if the tunnel remained unaffected.
- */
-GNUNET_PEER_Id
-GMT_notify_connection_broken (struct MeshTunnel3* t,
-                              GNUNET_PEER_Id p1, GNUNET_PEER_Id p2)
-{
-//   if (myid != p1 && myid != p2) FIXME
-//   {
-//     return;
-//   }
-//
-//   if (tree_get_predecessor (t->tree) != 0)
-//   {
-//     /* We are the peer still connected, notify owner of the disconnection. */
-//     struct GNUNET_MESH_PathBroken msg;
-//     struct GNUNET_PeerIdentity neighbor;
-//
-//     msg.header.size = htons (sizeof (msg));
-//     msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_PATH_BROKEN);
-//     GNUNET_PEER_resolve (t->id.oid, &msg.oid);
-//     msg.tid = htonl (t->id.tid);
-//     msg.peer1 = my_full_id;
-//     GNUNET_PEER_resolve (pid, &msg.peer2);
-//     GNUNET_PEER_resolve (tree_get_predecessor (t->tree), &neighbor);
-//     send_prebuilt_message (&msg.header, &neighbor, t);
-//   }
-  return 0;
-}
-
 /**
  * @brief Use the given path for the tunnel.
  * Update the next and prev hops (and RCs).
@@ -855,7 +933,7 @@ GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
 
   for (own_pos = 0; own_pos < p->length; own_pos++)
   {
-    if (p->peers[own_pos] == my_short_id)
+    if (p->peers[own_pos] == myid)
       break;
   }
   if (own_pos > p->length - 1)
@@ -871,46 +949,6 @@ GMT_use_path (struct MeshTunnel3 *t, struct MeshPeerPath *p)
 }
 
 
-/**
- * FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
- * Encrypt data with the tunnel key.
- *
- * @param t Tunnel whose key to use.
- * @param dst Destination for the encrypted data.
- * @param src Source of the plaintext.
- * @param size Size of the plaintext.
- * @param iv Initialization Vector to use.
- * @param fwd Is this a fwd message?
- */
-void
-GMT_encrypt (struct MeshTunnel3 *t,
-             void *dst, const void *src,
-             size_t size, uint64_t iv, int fwd)
-{
-  memcpy (dst, src, size);
-}
-
-
-/**
- * FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME FIXME
- * Decrypt data with the tunnel key.
- *
- * @param t Tunnel whose key to use.
- * @param dst Destination for the plaintext.
- * @param src Source of the encrypted data.
- * @param size Size of the encrypted data.
- * @param iv Initialization Vector to use.
- * @param fwd Is this a fwd message?
- */
-void
-GMT_decrypt (struct MeshTunnel3 *t,
-             void *dst, const void *src,
-             size_t size, uint64_t iv, int fwd)
-{
-  memcpy (dst, src, size);
-}
-
-
 /**
  * Count established (ready) connections of a tunnel.
  *
@@ -946,7 +984,7 @@ GMT_count_channels (struct MeshTunnel3 *t)
 
   for (count = 0, iter = t->channel_head;
        NULL != iter;
-  iter = iter->next, count++);
+       iter = iter->next, count++) /* skip */;
 
   return count;
 }
@@ -959,19 +997,24 @@ GMT_count_channels (struct MeshTunnel3 *t)
  *
  * @return Tunnel's state.
  */
-enum MeshTunnelState
+enum MeshTunnel3State
 GMT_get_state (struct MeshTunnel3 *t)
 {
+  if (NULL == t)
+    return (enum MeshTunnel3State) -1;
   return t->state;
 }
 
 /**
  * Get the total buffer space for a tunnel.
  *
+ * If terminal, use the biggest channel buffer (or 64) if no channel exists.
+ * If not terminal, use the sum of all connection buffers.
+ *
  * @param t Tunnel.
  * @param fwd Is this for FWD traffic?
  *
- * @return Buffer space offered by all connections in the tunnel.
+ * @return Buffer space offered by all entities (c/ch) in the tunnel.
  */
 unsigned int
 GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
@@ -989,7 +1032,10 @@ GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
     unsigned int ch_buf;
 
     if (NULL == t->channel_head)
+    {
+      /* Probably getting buffer for a channel create/handshake. */
       return 64;
+    }
 
     for (iter_ch = t->channel_head; NULL != iter_ch; iter_ch = iter_ch->next)
     {
@@ -1016,8 +1062,170 @@ GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
   return buffer;
 }
 
+
+/**
+ * Get the tunnel's destination.
+ *
+ * @param t Tunnel.
+ *
+ * @return ID of the destination peer.
+ */
+const struct GNUNET_PeerIdentity *
+GMT_get_destination (struct MeshTunnel3 *t)
+{
+  return GMP_get_id (t->peer);
+}
+
+
+/**
+ * Get the tunnel's next free global channel ID.
+ *
+ * @param t Tunnel.
+ *
+ * @return GID of a channel free to use.
+ */
+MESH_ChannelNumber
+GMT_get_next_chid (struct MeshTunnel3 *t)
+{
+  MESH_ChannelNumber chid;
+
+  while (NULL != GMT_get_channel (t, t->next_chid))
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG, "Channel %u exists...\n", t->next_chid);
+    t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
+  }
+  chid = t->next_chid;
+  t->next_chid = (t->next_chid + 1) & ~GNUNET_MESH_LOCAL_CHANNEL_ID_CLI;
+
+  return chid;
+}
+
+
+/**
+ * Send ACK on one or more channels due to buffer in connections..
+ *
+ * @param t Channel which has some free buffer space.
+ * @param fwd Is this for FWD traffic? (ACK goes to root)
+ */
+void
+GMT_unchoke_channels (struct MeshTunnel3 *t, int fwd)
+{
+  struct MeshTChannel *iter;
+  unsigned int buffer;
+  unsigned int channels = GMT_count_channels (t);
+  unsigned int choked_n;
+  struct MeshChannel *choked[channels];
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT_unchoke_channels on %s\n", GMT_2s (t));
+
+  if (NULL == t)
+  {
+    GNUNET_break (0);
+    return;
+  }
+
+  /* Get buffer space */
+  buffer = GMT_get_buffer (t, fwd);
+  if (0 == buffer)
+  {
+    return;
+  }
+
+  /* Count and remember choked channels */
+  choked_n = 0;
+  for (iter = t->channel_head; NULL != iter; iter = iter->next)
+  {
+    if (GNUNET_NO == GMCH_get_allowed (iter->ch, fwd))
+    {
+      choked[choked_n++] = iter->ch;
+    }
+  }
+
+  /* Unchoke random channels */
+  while (0 < buffer && 0 < choked_n)
+  {
+    unsigned int r = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
+                                               choked_n);
+    GMCH_allow_client (choked[r], fwd);
+    choked_n--;
+    buffer--;
+    choked[r] = choked[choked_n];
+  }
+}
+
+
 /**
- * Sends an already built message on a tunnel, choosing the best connection.
+ * Send ACK on one or more connections due to buffer space to the client.
+ *
+ * Iterates all connections of the tunnel and sends ACKs appropriately.
+ *
+ * @param t Tunnel.
+ * @param fwd Is this in for FWD traffic? (ACK goes dest->root)
+ */
+void
+GMT_send_acks (struct MeshTunnel3 *t, int fwd)
+{
+  struct MeshTConnection *iter;
+  uint32_t allowed;
+  uint32_t to_allow;
+  uint32_t allow_per_connection;
+  unsigned int cs;
+  unsigned int buffer;
+
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Tunnel send %s ACKs on %s\n",
+       fwd ? "FWD" : "BCK", GMT_2s (t));
+
+  if (NULL == t)
+  {
+    GNUNET_break (0);
+    return;
+  }
+  if (NULL == t->channel_head ||
+      GNUNET_NO == GMCH_is_origin (t->channel_head->ch, !fwd))
+  {
+    GNUNET_break (0);
+    return;
+  }
+
+  buffer = GMT_get_buffer (t, fwd);
+
+  /* Count connections, how many messages are already allowed */
+  cs = GMT_count_connections (t);
+  for (allowed = 0, iter = t->connection_head; NULL != iter; iter = iter->next)
+  {
+    allowed += GMC_get_allowed (iter->c, fwd);
+  }
+
+  /* Make sure there is no overflow */
+  if (allowed > buffer)
+  {
+    GNUNET_break (0);
+    return;
+  }
+
+  /* Authorize connections to send more data */
+  to_allow = buffer; /* - allowed; */
+
+  for (iter = t->connection_head; NULL != iter && to_allow > 0; iter = iter->next)
+  {
+    allow_per_connection = to_allow/cs;
+    to_allow -= allow_per_connection;
+    cs--;
+    if (GMC_get_allowed (iter->c, fwd) > 64 / 3)
+    {
+      continue;
+    }
+    GMC_allow (iter->c, buffer, fwd);
+  }
+
+  GNUNET_break (to_allow == 0);
+}
+
+
+/**
+ * Sends an already built message on a tunnel, GMT_encrypting it and
+ * choosing the best connection.
  *
  * @param message Message to send. Function modifies it.
  * @param t Tunnel on which this message is transmitted.
@@ -1025,28 +1233,39 @@ GMT_get_buffer (struct MeshTunnel3 *t, int fwd)
  * @param fwd Is this a fwd message?
  */
 void
-GMT_send_prebuilt_message (struct GNUNET_MESH_Encrypted *msg,
+GMT_send_prebuilt_message (const struct GNUNET_MessageHeader *message,
                            struct MeshTunnel3 *t,
                            struct MeshChannel *ch,
                            int fwd)
 {
   struct MeshConnection *c;
+  struct GNUNET_MESH_Encrypted *msg;
+  size_t size = ntohs (message->size);
+  char *cbuf[sizeof (struct GNUNET_MESH_Encrypted) + size];
+  uint64_t iv;
   uint16_t type;
 
-  LOG (GNUNET_ERROR_TYPE_DEBUG, "Send on Tunnel %s\n", GMP_2s (t->peer));
+  LOG (GNUNET_ERROR_TYPE_DEBUG, "GMT Send on Tunnel %s\n", GMP_2s (t->peer));
+
+  iv = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_NONCE, UINT64_MAX);
+  msg = (struct GNUNET_MESH_Encrypted *) cbuf;
+  msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_ENCRYPTED);
+  msg->header.size = htons (sizeof (struct GNUNET_MESH_Encrypted) + size);
+  msg->iv = GNUNET_htonll (iv);
+  GMT_encrypt (t, &msg[1], message, size, iv, fwd);
   c = tunnel_get_connection (t, fwd);
   if (NULL == c)
   {
     GNUNET_break (GNUNET_YES == t->destroy);
     return;
   }
-  type = ntohs (msg->header.type);
+  type = ntohs (message->type);
   switch (type)
   {
-    case GNUNET_MESSAGE_TYPE_MESH_FWD:
-    case GNUNET_MESSAGE_TYPE_MESH_BCK:
+    case GNUNET_MESSAGE_TYPE_MESH_DATA:
     case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_CREATE:
     case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_DESTROY:
+    case GNUNET_MESSAGE_TYPE_MESH_CHANNEL_ACK:
       msg->cid = *GMC_get_id (c);
       msg->ttl = htonl (default_ttl);
       break;
@@ -1057,5 +1276,95 @@ GMT_send_prebuilt_message (struct GNUNET_MESH_Encrypted *msg,
   }
   msg->reserved = 0;
 
+  t->pending_messages++;
   GMC_send_prebuilt_message (&msg->header, c, ch, fwd);
 }
+
+/**
+ * Is the tunnel directed towards the local peer?
+ *
+ * @param t Tunnel.
+ *
+ * @return GNUNET_YES if it is loopback.
+ */
+int
+GMT_is_loopback (const struct MeshTunnel3 *t)
+{
+  return (myid == GMP_get_short_id(t->peer));
+}
+
+
+/**
+ * Is the tunnel using this path already?
+ *
+ * @param t Tunnel.
+ * @param p Path.
+ *
+ * @return GNUNET_YES a connection uses this path.
+ */
+int
+GMT_is_path_used (const struct MeshTunnel3 *t, const struct MeshPeerPath *p)
+{
+  struct MeshTConnection *iter;
+
+  for (iter = t->connection_head; NULL != iter; iter = iter->next)
+    if (GMC_get_path (iter->c) == p)
+      return GNUNET_YES;
+
+  return GNUNET_NO;
+}
+
+
+/**
+ * Get a cost of a path for a tunnel considering existing connections.
+ *
+ * @param t Tunnel.
+ * @param path Candidate path.
+ *
+ * @return Cost of the path (path length + number of overlapping nodes)
+ */
+unsigned int
+GMT_get_path_cost (const struct MeshTunnel3 *t,
+                   const struct MeshPeerPath *path)
+{
+  struct MeshTConnection *iter;
+  unsigned int overlap;
+  unsigned int i;
+  unsigned int j;
+
+  if (NULL == path)
+    return 0;
+
+  overlap = 0;
+  GNUNET_assert (NULL != t);
+
+  for (i = 0; i < path->length; i++)
+  {
+    for (iter = t->connection_head; NULL != iter; iter = iter->next)
+    {
+      for (j = 0; j < GMC_get_path (iter->c)->length; j++)
+      {
+        if (path->peers[i] == GMC_get_path (iter->c)->peers[j])
+        {
+          overlap++;
+          break;
+        }
+      }
+    }
+  }
+  return (path->length + overlap) * (path->score * -1);
+}
+
+
+/**
+ * Get the static string for the peer this tunnel is directed.
+ *
+ * @param t Tunnel.
+ *
+ * @return Static string the destination peer's ID.
+ */
+const char *
+GMT_2s (const struct MeshTunnel3 *t)
+{
+  return GMP_2s (t->peer);
+}
\ No newline at end of file