2 This file is part of GNUnet.
3 (C) 2011 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file dht/gnunet-service-xdht_routing.c
23 * @brief GNUnet DHT tracking of requests for routing replies
24 * @author Supriti Singh
27 #include "gnunet-service-xdht_neighbours.h"
28 #include "gnunet-service-xdht_routing.h"
29 #include "gnunet-service-xdht.h"
33 * Number of requests we track at most (for routing replies).
35 #define DHT_MAX_RECENT (1024 * 16)
38 * Maximum number of entries in routing table.
40 #define ROUTING_TABLE_THRESHOLD 64
43 * Routing table entry .
50 struct GNUNET_PeerIdentity source;
55 struct GNUNET_PeerIdentity destination;
58 * The peer to which this request should be passed to.
60 struct GNUNET_PeerIdentity next_hop;
63 * Peer just before next hop in the trail.
65 struct GNUNET_PeerIdentity prev_hop;
71 * Routing table of the peer
73 static struct GNUNET_CONTAINER_MultiPeerMap *routing_table;
77 * Add a new entry to our routing table.
78 * @param source peer Source of the trail.
79 * @param destintation Destination of the trail.
80 * @param next_hop Next peer to forward the message to reach the destination.
82 * GNUNET_SYSERR If the number of routing entries crossed thershold.
85 GDS_ROUTING_add (struct GNUNET_PeerIdentity *source,
86 struct GNUNET_PeerIdentity *dest,
87 struct GNUNET_PeerIdentity *next_hop,
88 const struct GNUNET_PeerIdentity *prev_hop)
90 struct RoutingTrail *new_routing_entry;
92 if (GNUNET_CONTAINER_multipeermap_size(routing_table) > ROUTING_TABLE_THRESHOLD)
94 //FPRINTF (stderr,_("\nSUPU ROUTING ADD %s, %s, %d"),__FILE__, __func__,__LINE__);
95 new_routing_entry = GNUNET_malloc (sizeof (struct RoutingTrail));
96 memcpy (&(new_routing_entry->source) , source, sizeof (struct GNUNET_PeerIdentity));
97 memcpy (&(new_routing_entry->next_hop), next_hop, sizeof (struct GNUNET_PeerIdentity));
98 memcpy (&(new_routing_entry->destination), dest, sizeof (struct GNUNET_PeerIdentity));
99 memcpy (&(new_routing_entry->prev_hop), prev_hop, sizeof (struct GNUNET_PeerIdentity));
101 GNUNET_assert (GNUNET_OK ==
102 GNUNET_CONTAINER_multipeermap_put (routing_table,
103 dest, new_routing_entry,
104 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
110 * Iterate over multiple entries for same destinational value and get
111 * the correct next hop.
112 * @param cls struct RoutingTrail
113 * @param key Destination identity
114 * @param value struct RoutingTrail
115 * @return #GNUNET_YES to continue looking, #GNUNET_NO if we found the next hop
118 get_next_hop (void *cls, const struct GNUNET_PeerIdentity *key, void *value)
120 /* Here you should match if source, prev hop matches if yes then send
121 GNUNET_NO as you don't need to check more entries. */
122 struct RoutingTrail *request = cls;
123 struct RoutingTrail *existing_entry = (struct RoutingTrail *)value;
125 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(request->source), &(existing_entry->source)))
127 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&(request->prev_hop), &(existing_entry->prev_hop)))
129 memcpy (&(request->next_hop), &(existing_entry->next_hop), sizeof (struct GNUNET_PeerIdentity));
138 * Find the next hop to send packet to.
139 * @param source_peer Source of the trail.
140 * @param destination_peer Destination of the trail.
141 * @param prev_hop Previous hop in the trail.
142 * @return Next hop in the trail from source to destination.
144 struct GNUNET_PeerIdentity *
145 GDS_ROUTING_search(struct GNUNET_PeerIdentity *source_peer,
146 struct GNUNET_PeerIdentity *destination_peer,
147 const struct GNUNET_PeerIdentity *prev_hop)
149 struct RoutingTrail *trail;
150 trail = GNUNET_malloc (sizeof (struct RoutingTrail));
151 memcpy (&(trail->destination), destination_peer, sizeof (struct GNUNET_PeerIdentity));
152 memcpy (&(trail->source), source_peer, sizeof (struct GNUNET_PeerIdentity));
153 memcpy (&(trail->prev_hop), prev_hop, sizeof (struct GNUNET_PeerIdentity));
154 //trail->next_hop = NULL;
155 //FPRINTF (stderr,_("\nSUPU ROUTING SEARCH %s, %s, %d"),__FILE__, __func__,__LINE__);
156 GNUNET_CONTAINER_multipeermap_get_multiple (routing_table, destination_peer,
157 get_next_hop, trail);
159 return &(trail->next_hop);
165 /**FIXME: Old implementation just to remove error
166 * Handle a reply (route to origin). Only forwards the reply back to
167 * other peers waiting for it. Does not do local caching or
168 * forwarding to local clients. Essentially calls
169 * GDS_NEIGHBOURS_handle_reply for all peers that sent us a matching
172 * @param type type of the block
173 * @param expiration_time when does the content expire
174 * @param key key for the content
175 * @param put_path_length number of entries in put_path
176 * @param put_path peers the original PUT traversed (if tracked)
177 * @param get_path_length number of entries in get_path
178 * @param get_path peers this reply has traversed so far (if tracked)
179 * @param data payload of the reply
180 * @param data_size number of bytes in data
183 GDS_ROUTING_process (enum GNUNET_BLOCK_Type type,
184 struct GNUNET_TIME_Absolute expiration_time,
185 const struct GNUNET_HashCode * key, unsigned int put_path_length,
186 const struct GNUNET_PeerIdentity *put_path,
187 unsigned int get_path_length,
188 const struct GNUNET_PeerIdentity *get_path,
189 const void *data, size_t data_size)
196 * Initialize routing subsystem.
201 routing_table = GNUNET_CONTAINER_multipeermap_create (DHT_MAX_RECENT * 4 / 3, GNUNET_NO);
206 * Shutdown routing subsystem.
211 GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (routing_table));
212 GNUNET_CONTAINER_multipeermap_destroy (routing_table);
215 /* end of gnunet-service-xdht_routing.c */