/*
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
#include "gnunet-service-xdht_routing.h"
#include "gnunet-service-xdht.h"
-
/**
- * Number of requests we track at most (for routing replies).
+ * Maximum number of entries in routing table.
*/
-#define DHT_MAX_RECENT (1024 * 16)
+#define ROUTING_TABLE_THRESHOLD 64
/**
- * FIXME: Do we need a field prev_hop
+ * FIXME: do we need to store destination and source.
+ * because in trail teardown we will reach destination but it will not find any
+ * entry in routing table. so we should store destination and source.
* Routing table entry .
*/
struct RoutingTrail
{
/**
- * Source peer .
- */
- struct GNUNET_PeerIdentity source;
-
- /**
- * Destination peer.
+ * Global Unique identifier of the trail.
*/
- struct GNUNET_PeerIdentity destination;
-
+ struct GNUNET_HashCode trail_id;
+
/**
* The peer to which this request should be passed to.
*/
struct GNUNET_PeerIdentity next_hop;
+ /**
+ * Peer just before next hop in the trail.
+ */
+ struct GNUNET_PeerIdentity prev_hop;
};
-
/**
* Routing table of the peer
*/
-static struct GNUNET_CONTAINER_MultiPeerMap *routing_table;
+static struct GNUNET_CONTAINER_MultiHashMap *routing_table;
+
+/**
+ * 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_update_trail_prev_hop (const struct GNUNET_HashCode trail_id,
+ struct GNUNET_PeerIdentity prev_hop)
+{
+ struct RoutingTrail *trail;
+
+ trail = GNUNET_CONTAINER_multihashmap_get (routing_table, &trail_id);
+
+ if (NULL == trail)
+ return GNUNET_SYSERR;
+
+ trail->prev_hop = prev_hop;
+ return GNUNET_OK;
+}
/**
- * FIXME: Change the name of variable.
- * Ensure that everywhere in this file you are using destination as the key.
- * Do we need prev field in routing table?
- * Add a new entry to our routing table.
- * @param source peer
- * @param destintation
- * @param next_hop
+ * 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.
*/
-void
-GDS_ROUTING_add (struct GNUNET_PeerIdentity *source,
- struct GNUNET_PeerIdentity *dest,
- struct GNUNET_PeerIdentity *next_hop)
+struct GNUNET_PeerIdentity *
+GDS_ROUTING_get_next_hop (const struct GNUNET_HashCode trail_id,
+ enum GDS_ROUTING_trail_direction trail_direction)
{
- struct RoutingTrail *new_routing_entry;
-
- /* If dest is already present in the routing table, then exit.*/
- if (GNUNET_YES ==
- GNUNET_CONTAINER_multipeermap_contains (routing_table, dest))
+ struct RoutingTrail *trail;
+
+ trail = GNUNET_CONTAINER_multihashmap_get (routing_table, &trail_id);
+
+ if (NULL == trail)
+ return NULL;
+
+ switch (trail_direction)
{
- GNUNET_break (0);
- return;
+ case GDS_ROUTING_SRC_TO_DEST:
+ return &(trail->next_hop);
+ case GDS_ROUTING_DEST_TO_SRC:
+ return &(trail->prev_hop);
}
+ return NULL;
+}
+
+
+/**
+ * Remove trail with trail_id
+ * @param trail_id Trail id to be removed
+ * @return #GNUNET_YES success
+ * #GNUNET_NO if entry not found.
+ */
+int
+GDS_ROUTING_remove_trail (const struct GNUNET_HashCode remove_trail_id)
+{
+ struct RoutingTrail *remove_entry;
- 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));
+ remove_entry = GNUNET_CONTAINER_multihashmap_get (routing_table, &remove_trail_id);
- GNUNET_assert (GNUNET_OK ==
- GNUNET_CONTAINER_multipeermap_put (routing_table,
- dest, new_routing_entry,
- GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
+ if (NULL == remove_entry)
+ return GNUNET_NO;
+
+ if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (routing_table,
+ &remove_trail_id,
+ remove_entry))
+ {
+ GNUNET_free (remove_entry);
+ return GNUNET_YES;
+ }
+ return GNUNET_NO;
}
-/**FIXME: Test if its correct or not.
- * Find the next hop to send packet to .
- * @return next hop peer id
+/**
+ * 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)
+static int remove_matching_trails (void *cls,
+ const struct GNUNET_HashCode *key,
+ void *value)
{
- struct RoutingTrail *trail;
- trail = (struct RoutingTrail *)(GNUNET_CONTAINER_multipeermap_get(routing_table,destination_peer));
-
- if(trail == NULL)
- return NULL;
-
- return &(trail->next_hop);
+ struct RoutingTrail *remove_trail = cls;
+ struct GNUNET_PeerIdentity *peer = value;
+
+ if ((0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_trail->next_hop, peer)) ||
+ (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_trail->prev_hop, peer)))
+ {
+ GNUNET_assert (GNUNET_YES ==
+ GNUNET_CONTAINER_multihashmap_remove (routing_table,
+ &remove_trail->trail_id,
+ remove_trail));
+ GNUNET_free (remove_trail);
+ }
+ return GNUNET_YES;
}
-/**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
+/**
+ * * FIXME: when a friend gets disconnected, then we remove the entry from routing
+ * table where this friend is either a next_hop or prev_hop. But we don't communicate
+ * that the trail is broken to any one who is part of trail. Should we communicate or
+ * not. And if not then the cases where trail setup fails because next_hop = NULL
+ * or something like that. VERY URGENT.
+ * Remove every trail where peer is either next_hop or prev_hop
+ * @param peer Peer to be searched.
*/
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)
+GDS_ROUTING_remove_trail_by_peer (const struct GNUNET_PeerIdentity *peer)
+{
+ GNUNET_CONTAINER_multihashmap_iterate (routing_table, &remove_matching_trails,
+ (void *)peer);
+}
+
+
+/**
+ * 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
+ */
+int
+GDS_ROUTING_add (struct GNUNET_HashCode new_trail_id,
+ struct GNUNET_PeerIdentity *prev_hop,
+ const struct GNUNET_PeerIdentity *next_hop)
+{
+ 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 #GNUNET_YES, if threshold crossed else #GNUNET_NO.
+ */
+int
+GDS_ROUTING_threshold_reached (void)
{
- return;
+ return (GNUNET_CONTAINER_multihashmap_size(routing_table) >
+ ROUTING_TABLE_THRESHOLD) ? GNUNET_YES:GNUNET_NO;
}
* Initialize routing subsystem.
*/
void
-GDS_ROUTING_init ()
+GDS_ROUTING_init (void)
{
- routing_table = GNUNET_CONTAINER_multipeermap_create (DHT_MAX_RECENT * 4 / 3, GNUNET_NO);
+ routing_table = GNUNET_CONTAINER_multihashmap_create (ROUTING_TABLE_THRESHOLD * 4 / 3,
+ GNUNET_NO);
}
* 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