-fix time assertion introduce in last patch
[oweals/gnunet.git] / src / dht / gnunet-service-xdht_routing.c
index f083b6e6241c1ba3ff9edcc359124d343d518ef3..e320c2df922b951efd812abd7173c1f77217d23b 100644 (file)
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     (C) 2011 Christian Grothoff (and other contributing authors)
+     (C) 2011 - 2014 Christian Grothoff (and other contributing authors)
 
      GNUnet is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published
 
 
 /**
- * Number of requests we track at most (for routing replies).
+ * FIXME: Check if its better to store pointer to friend rather than storing
+ * peer identity next_hop or prev_hop. 
+ * keep entries in destnation and source peer also. so when we send the trail
+ * teardown message then we don't know the source but if source gets the message
+ * then it shold remove that trail id from its finger table. But how does
+ * source know what is the desination finger ? It will whenevr contact a trail
+ * will do a lookup in routing table and if no trail id present the remove
+ * that trail of the finger and if only one trail then remove the finger.
+ * because of this use case of trail teardown I think trail compression
+ * and trail teardown should not be merged. 
+ * 2. store a pointer to friendInfo in place o peer identity. 
  */
-#define DHT_MAX_RECENT (1024 * 16)
-
 /**
- * Maximum number of entries in routing table. 
+ * Maximum number of entries in routing table.
  */
 #define ROUTING_TABLE_THRESHOLD 64
 
 struct RoutingTrail
 {
   /**
-   * Source peer .
+   * Global Unique identifier of the trail.
    */
-  struct GNUNET_PeerIdentity source;
-
-  /**
-   * Destination peer.
-   */
-  struct GNUNET_PeerIdentity destination;
+  struct GNUNET_HashCode trail_id;
 
   /**
    * The peer to which this request should be passed to.
    */
-  struct GNUNET_PeerIdentity next_hop;
-  
+  struct GNUNET_PeerIdentity next_hop; 
+
   /**
-   * Peer just before next hop in the trail. 
+   * Peer just before next hop in the trail.
    */
-  struct GNUNET_PeerIdentity prev_hop;
-  
+  struct GNUNET_PeerIdentity prev_hop;  
 };
 
-
 /**
  * Routing table of the peer
  */
-static struct GNUNET_CONTAINER_MultiPeerMap *routing_table;
-
+static struct GNUNET_CONTAINER_MultiHashMap *routing_table;
 
 /**
- * Add a new entry to our routing table.
- * @param source peer Source of the trail.
- * @param destintation Destination of the trail.
- * @param next_hop Next peer to forward the message to reach the destination.
- * @return GNUNET_YES
- *         GNUNET_SYSERR If the number of routing entries crossed thershold.
+ * Update the prev. hop of the trail. Call made by trail teardown where
+ * if you are the first friend now in the trail then you need to update
+ * your prev. hop.
+ * @param trail_id
+ * @return #GNUNET_OK success
+ *         #GNUNET_SYSERR in case no matching entry found in routing table.
  */
 int
-GDS_ROUTING_add (struct GNUNET_PeerIdentity *source,
-                 struct GNUNET_PeerIdentity *dest,
-                 const struct GNUNET_PeerIdentity *next_hop,
-                 struct GNUNET_PeerIdentity *prev_hop)
+GDS_ROUTING_update_trail_prev_hop (const struct GNUNET_HashCode trail_id,
+                                   struct GNUNET_PeerIdentity prev_hop)
 {
-  struct RoutingTrail *new_routing_entry;
-    
-  if (GNUNET_CONTAINER_multipeermap_size(routing_table) > ROUTING_TABLE_THRESHOLD)
+  struct RoutingTrail *trail;
+
+  trail = GNUNET_CONTAINER_multihashmap_get (routing_table, &trail_id);
+
+  if (NULL == trail)
     return GNUNET_SYSERR;
-  //FPRINTF (stderr,_("\nSUPU ROUTING ADD %s, %s, %d"),__FILE__, __func__,__LINE__);
-  new_routing_entry = GNUNET_malloc (sizeof (struct RoutingTrail));
-  memcpy (&(new_routing_entry->source) , source, sizeof (struct GNUNET_PeerIdentity));
-  memcpy (&(new_routing_entry->next_hop), next_hop, sizeof (struct GNUNET_PeerIdentity));
-  memcpy (&(new_routing_entry->destination), dest, sizeof (struct GNUNET_PeerIdentity));
-  memcpy (&(new_routing_entry->prev_hop), prev_hop, sizeof (struct GNUNET_PeerIdentity));
-  
-  GNUNET_assert (GNUNET_OK ==
-    GNUNET_CONTAINER_multipeermap_put (routing_table,
-                                       dest, new_routing_entry,
-                                       GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
-  
-  /* SUPU TEST CODE */
-  /* Here I want to see if routing table is correct or not. */
-  int test_index;
-  struct GNUNET_CONTAINER_MultiPeerMapIterator *test_iter;
-  struct GNUNET_PeerIdentity *print_peer;
-  print_peer = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity));
-  struct RoutingTrail *test_trail;
-  test_iter = GNUNET_CONTAINER_multipeermap_iterator_create (routing_table); 
-  for (test_index = 0; test_index < GNUNET_CONTAINER_multipeermap_size (routing_table); test_index++)
+
+  trail->prev_hop = prev_hop;
+  return GNUNET_OK;
+}
+
+
+
+/**
+ * Get the next hop for trail corresponding to trail_id
+ * @param trail_id Trail id to be searched.
+ * @return Next_hop if found
+ *         NULL If next hop not found.
+ */
+struct GNUNET_PeerIdentity *
+GDS_ROUTING_get_next_hop (const struct GNUNET_HashCode trail_id,
+                          enum GDS_ROUTING_trail_direction trail_direction)
+{
+  struct RoutingTrail *trail;
+
+  trail = GNUNET_CONTAINER_multihashmap_get (routing_table, &trail_id);
+
+  if (NULL == trail)
+    return NULL;
+
+  switch (trail_direction)
   {
-    FPRINTF (stderr,_("\nSUPU %s, %s, %d, entry[%d]"),__FILE__, __func__,__LINE__,test_index);
-    if(GNUNET_YES == GNUNET_CONTAINER_multipeermap_iterator_next (test_iter, NULL,
-                                                                 (const void **)&test_trail)) 
-    {
-      memcpy (print_peer, &(test_trail->source),sizeof (struct GNUNET_PeerIdentity));
-      FPRINTF (stderr,_("\nSUPU %s, %s, %d, test_trail->source =%s"),__FILE__, __func__,__LINE__,GNUNET_i2s (print_peer));
-      memcpy (print_peer, &(test_trail->destination),sizeof (struct GNUNET_PeerIdentity));
-      FPRINTF (stderr,_("\nSUPU %s, %s, %d, test_trail->destination =%s"),__FILE__, __func__,__LINE__,GNUNET_i2s(print_peer));
-      memcpy (print_peer, &(test_trail->prev_hop),sizeof (struct GNUNET_PeerIdentity));
-      FPRINTF (stderr,_("\nSUPU %s, %s, %d, test_trail->prev_hop =%s"),__FILE__, __func__,__LINE__,GNUNET_i2s(print_peer));
-      memcpy (print_peer, &(test_trail->next_hop),sizeof (struct GNUNET_PeerIdentity));
-      FPRINTF (stderr,_("\nSUPU %s, %s, %d, test_trail->next_hop =%s"),__FILE__, __func__,__LINE__,GNUNET_i2s(print_peer));
-      
-    }
+    case GDS_ROUTING_SRC_TO_DEST:
+      return &(trail->next_hop);
+    case GDS_ROUTING_DEST_TO_SRC:
+      return &(trail->prev_hop);
   }
-  /* SUPU TEST CODE ENDS*/
-  return GNUNET_YES;
+  return NULL;
 }
 
 
 /**
- * Iterate over multiple entries for same destinational value and get
- * the correct next hop.
- * @param cls struct RoutingTrail
- * @param key Destination identity
- * @param value struct RoutingTrail
- * @return #GNUNET_YES to continue looking, #GNUNET_NO if we found the next hop
+ * Remove trail with trail_id
+ * @param trail_id Trail id to be removed
+ * @return #GNUNET_YES success
+ *         #GNUNET_NO if entry not found.
  */
 int
-get_next_hop (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
+GDS_ROUTING_remove_trail (const struct GNUNET_HashCode remove_trail_id)
 {
-  /* Here you should match if source, prev hop matches if yes then send 
-   GNUNET_NO as you don't need to check more entries. */
-  struct RoutingTrail *request = cls;
-  struct RoutingTrail *existing_entry = (struct RoutingTrail *)value;
-  
-  if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(request->source), &(existing_entry->source)))
+  struct RoutingTrail *remove_entry;
+
+  remove_entry = GNUNET_CONTAINER_multihashmap_get (routing_table, &remove_trail_id);
+
+  if (NULL == remove_entry)
+    return GNUNET_NO;
+
+  if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (routing_table,
+                                                          &remove_trail_id,
+                                                          remove_entry))
   {
-    if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(request->prev_hop), &(existing_entry->prev_hop)))
-    {
-      memcpy (&(request->next_hop), &(existing_entry->next_hop), sizeof (struct GNUNET_PeerIdentity));
-      return GNUNET_YES;
-    }
+    GNUNET_free (remove_entry);
+    return GNUNET_YES;
   }
   return GNUNET_NO;
 }
 
 
 /**
- * Find the next hop to send packet to.
- * @param source_peer Source of the trail.
- * @param destination_peer Destination of the trail.
- * @param prev_hop Previous hop in the trail. 
- * @return Next hop in the trail from source to destination. 
+ * Iterate over routing table and remove entries with value as part of any trail.
+ * 
+ * @param cls closure
+ * @param key current public key
+ * @param value value in the hash map
+ * @return #GNUNET_YES if we should continue to iterate,
+ *         #GNUNET_NO if not.
  */
-struct GNUNET_PeerIdentity *
-GDS_ROUTING_search(struct GNUNET_PeerIdentity *source_peer,
-                   struct GNUNET_PeerIdentity *destination_peer,
-                   const struct GNUNET_PeerIdentity *prev_hop)
+static int remove_matching_trails (void *cls,
+                                   const struct GNUNET_HashCode *key,
+                                   void *value)
+{
+  struct RoutingTrail *remove_trail = cls;
+  struct GNUNET_PeerIdentity *disconnected_peer = value;
+  
+  /* If disconnected_peer is next_hop, then send a trail teardown message through
+   * prev_hop in direction from destination to source. */
+  if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_trail->next_hop, 
+                                            disconnected_peer)) 
+  {
+    GDS_NEIGHBOURS_send_trail_teardown (remove_trail->trail_id, 
+                                        GDS_ROUTING_DEST_TO_SRC,
+                                        &remove_trail->prev_hop);
+  }
+  
+  /* If disconnected_peer is prev_hop, then send a trail teardown through
+   * next_hop in direction from Source to Destination. */
+  if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_trail->prev_hop, 
+                                            disconnected_peer))
+  {
+    GDS_NEIGHBOURS_send_trail_teardown (remove_trail->trail_id, 
+                                        GDS_ROUTING_SRC_TO_DEST,
+                                        &remove_trail->next_hop);
+  }
+  
+  GNUNET_assert (GNUNET_YES ==
+                   GNUNET_CONTAINER_multihashmap_remove (routing_table,
+                                                         &remove_trail->trail_id,
+                                                         remove_trail));
+  GNUNET_free (remove_trail);
+  return GNUNET_YES;
+}
+
+#if 0
+/**
+ * TEST FUNCTION
+ * Remove after using. 
+ */
+void 
+GDS_ROUTING_test_print (void)
 {
+  struct GNUNET_CONTAINER_MultiHashMapIterator *iter;
   struct RoutingTrail *trail;
-  trail = GNUNET_malloc (sizeof (struct RoutingTrail));
-  memcpy (&(trail->destination), destination_peer, sizeof (struct GNUNET_PeerIdentity));
-  memcpy (&(trail->source), source_peer, sizeof (struct GNUNET_PeerIdentity));
-  memcpy (&(trail->prev_hop), prev_hop, sizeof (struct GNUNET_PeerIdentity));
-  //trail->next_hop = NULL;
-  //FPRINTF (stderr,_("\nSUPU ROUTING SEARCH %s, %s, %d"),__FILE__, __func__,__LINE__);
-  GNUNET_CONTAINER_multipeermap_get_multiple (routing_table, destination_peer,
-                                              get_next_hop, trail);
-  if(trail != NULL)
-    return &(trail->next_hop);
-  else
-    return NULL;
+  struct GNUNET_PeerIdentity print_peer;
+  struct GNUNET_HashCode key_ret;
+  int i;
+  
+   FPRINTF (stderr,_("\nSUPU ***PRINTING ROUTING TABLE *****"));
+  iter =GNUNET_CONTAINER_multihashmap_iterator_create (routing_table);
+  for (i = 0; i < GNUNET_CONTAINER_multihashmap_size(routing_table); i++)
+  {
+    if(GNUNET_YES == GNUNET_CONTAINER_multihashmap_iterator_next (iter,
+                                                                  &key_ret,
+                                                                  (const void **)&trail))
+    {
+      FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail->trail_id = %s"),
+              __FILE__, __func__,__LINE__, GNUNET_h2s(&trail->trail_id));
+      memcpy (&print_peer, &trail->next_hop, sizeof (struct GNUNET_PeerIdentity));
+      FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail->next_hop = %s"),
+              __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer));
+      memcpy (&print_peer, &trail->prev_hop, sizeof (struct GNUNET_PeerIdentity));
+      FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail->prev_hop = %s"),
+              __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer));
+    }
+  }
+}
+#endif
+/**
+ * Remove every trail where peer is either next_hop or prev_hop. Also send a 
+ * trail teardown message in direction of hop which is not disconnected.
+ * @param peer Peer identity. Trail containing this peer should be removed.
+ */
+void
+GDS_ROUTING_remove_trail_by_peer (const struct GNUNET_PeerIdentity *peer)
+{
+  GNUNET_CONTAINER_multihashmap_iterate (routing_table, &remove_matching_trails,
+                                         (void *)peer);
 }
 
 
-/**FIXME: Old implementation just to remove error
- * Handle a reply (route to origin).  Only forwards the reply back to
- * other peers waiting for it.  Does not do local caching or
- * forwarding to local clients.  Essentially calls
- * GDS_NEIGHBOURS_handle_reply for all peers that sent us a matching
- * request recently.
- *
- * @param type type of the block
- * @param expiration_time when does the content expire
- * @param key key for the content
- * @param put_path_length number of entries in put_path
- * @param put_path peers the original PUT traversed (if tracked)
- * @param get_path_length number of entries in get_path
- * @param get_path peers this reply has traversed so far (if tracked)
- * @param data payload of the reply
- * @param data_size number of bytes in data
+/**
+ * Add a new entry in routing table
+ * @param new_trail_id
+ * @param prev_hop
+ * @param next_hop
+ * @return #GNUNET_OK success
+ *         #GNUNET_SYSERR in case new_trail_id already exists in the network
+ *                         but with different prev_hop/next_hop
  */
-void
-GDS_ROUTING_process (enum GNUNET_BLOCK_Type type,
-                     struct GNUNET_TIME_Absolute expiration_time,
-                     const struct GNUNET_HashCode * key, unsigned int put_path_length,
-                     const struct GNUNET_PeerIdentity *put_path,
-                     unsigned int get_path_length,
-                     const struct GNUNET_PeerIdentity *get_path,
-                     const void *data, size_t data_size)
+int
+GDS_ROUTING_add (struct GNUNET_HashCode new_trail_id,
+                 struct GNUNET_PeerIdentity prev_hop,
+                 struct GNUNET_PeerIdentity next_hop)
 {
-  return;
+  struct RoutingTrail *new_entry;
+
+  new_entry = GNUNET_malloc (sizeof (struct RoutingTrail));
+  new_entry->trail_id = new_trail_id;
+  new_entry->next_hop = next_hop;
+  new_entry->prev_hop = prev_hop;
+  return GNUNET_CONTAINER_multihashmap_put (routing_table,
+                                            &new_trail_id, new_entry,
+                                            GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 }
 
+
 /**
- * Check if the size of routing table has crossed threshold. 
- * @return 
+ * Check if the size of routing table has crossed ROUTING_TABLE_THRESHOLD.
+ * It means that I don't have any more space in my routing table and I can not
+ * be part of any more trails till there is free space in my routing table.
+ * @return #GNUNET_YES, if threshold crossed else #GNUNET_NO.
  */
 int
-GDS_ROUTING_size ()
+GDS_ROUTING_threshold_reached (void)
 {
-  int ret;
-  ret = (GNUNET_CONTAINER_multipeermap_size(routing_table) > ROUTING_TABLE_THRESHOLD) ? 0:1;
-  return ret;    
+  return (GNUNET_CONTAINER_multihashmap_size(routing_table) >
+          ROUTING_TABLE_THRESHOLD) ? GNUNET_YES:GNUNET_NO;
 }
 
 
@@ -235,9 +288,10 @@ GDS_ROUTING_size ()
  * Initialize routing subsystem.
  */
 void
-GDS_ROUTING_init ()
-{ 
-  routing_table = GNUNET_CONTAINER_multipeermap_create (DHT_MAX_RECENT * 4 / 3, GNUNET_NO);
+GDS_ROUTING_init (void)
+{
+  routing_table = GNUNET_CONTAINER_multihashmap_create (ROUTING_TABLE_THRESHOLD * 4 / 3,
+                                                        GNUNET_NO);
 }
 
 
@@ -245,10 +299,10 @@ GDS_ROUTING_init ()
  * Shutdown routing subsystem.
  */
 void
-GDS_ROUTING_done ()
+GDS_ROUTING_done (void)
 {
-  GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (routing_table));
-  GNUNET_CONTAINER_multipeermap_destroy (routing_table);
+  GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (routing_table));
+  GNUNET_CONTAINER_multihashmap_destroy (routing_table);
 }
 
-/* end of gnunet-service-xdht_routing.c */
\ No newline at end of file
+/* end of gnunet-service-xdht_routing.c */