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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 * FIXME: Check if its better to store pointer to friend rather than storing
34 * peer identity next_hop or prev_hop.
35 * keep entries in destnation and source peer also. so when we send the trail
36 * teardown message then we don't know the source but if source gets the message
37 * then it shold remove that trail id from its finger table. But how does
38 * source know what is the desination finger ? It will whenevr contact a trail
39 * will do a lookup in routing table and if no trail id present the remove
40 * that trail of the finger and if only one trail then remove the finger.
41 * because of this use case of trail teardown I think trail compression
42 * and trail teardown should not be merged.
43 * 2. store a pointer to friendInfo in place o peer identity.
46 * Maximum number of entries in routing table.
48 #define ROUTING_TABLE_THRESHOLD 80000
51 * FIXME: Store friend pointer instead of peer identifier.
52 * Routing table entry .
57 * Global Unique identifier of the trail.
59 struct GNUNET_HashCode trail_id;
62 * The peer to which this request should be passed to.
64 struct GNUNET_PeerIdentity next_hop;
67 * Peer just before next hop in the trail.
69 struct GNUNET_PeerIdentity prev_hop;
73 * Routing table of the peer
75 static struct GNUNET_CONTAINER_MultiHashMap *routing_table;
78 * Update the prev. hop of the trail. Call made by trail compression where
79 * if you are the first friend now in the trail then you need to update
82 * @return #GNUNET_OK success
83 * #GNUNET_SYSERR in case no matching entry found in routing table.
86 GDS_ROUTING_update_trail_prev_hop (const struct GNUNET_HashCode *trail_id,
87 const struct GNUNET_PeerIdentity *prev_hop)
89 struct RoutingTrail *trail;
91 trail = GNUNET_CONTAINER_multihashmap_get (routing_table,
96 trail->prev_hop = *prev_hop;
102 * Update the next hop of the trail. Call made by trail compression where
103 * if you are source of the trail and now you have a new first friend, then
104 * you should update the trail.
106 * @return #GNUNET_OK success
107 * #GNUNET_SYSERR in case no matching entry found in routing table.
110 GDS_ROUTING_update_trail_next_hop (const struct GNUNET_HashCode *trail_id,
111 const struct GNUNET_PeerIdentity *next_hop)
113 struct RoutingTrail *trail;
115 trail = GNUNET_CONTAINER_multihashmap_get (routing_table,
118 return GNUNET_SYSERR;
119 trail->next_hop = *next_hop;
125 * Get the next hop for trail corresponding to trail_id
127 * @param trail_id Trail id to be searched.
128 * @return Next_hop if found
129 * NULL If next hop not found.
131 const struct GNUNET_PeerIdentity *
132 GDS_ROUTING_get_next_hop (const struct GNUNET_HashCode *trail_id,
133 enum GDS_ROUTING_trail_direction trail_direction)
135 struct RoutingTrail *trail;
137 trail = GNUNET_CONTAINER_multihashmap_get (routing_table,
141 /* If a friend got disconnected and we removed all the entry from the
142 routing table, then trail will be deleted and my identity will not know
143 and when it tries to reach to that finger it fails. thats why
144 assertion always fails in*/
147 switch (trail_direction)
149 case GDS_ROUTING_SRC_TO_DEST:
150 return &trail->next_hop;
151 case GDS_ROUTING_DEST_TO_SRC:
152 return &trail->prev_hop;
159 * Remove trail with trail_id
160 * @param trail_id Trail id to be removed
161 * @return #GNUNET_YES success
162 * #GNUNET_NO if entry not found.
165 GDS_ROUTING_remove_trail (const struct GNUNET_HashCode *remove_trail_id)
167 struct RoutingTrail *remove_entry;
169 remove_entry = GNUNET_CONTAINER_multihashmap_get (routing_table,
171 if (NULL == remove_entry)
175 GNUNET_CONTAINER_multihashmap_remove (routing_table,
179 GNUNET_free (remove_entry);
187 * Iterate over routing table and remove entries with value as part of any trail.
190 * @param key current public key
191 * @param value value in the hash map
192 * @return #GNUNET_YES if we should continue to iterate,
196 remove_matching_trails (void *cls,
197 const struct GNUNET_HashCode *key,
200 struct RoutingTrail *remove_trail = value;
201 struct GNUNET_PeerIdentity *disconnected_peer = cls;
202 struct GNUNET_HashCode trail_id = *key;
203 struct GNUNET_PeerIdentity my_identity;
205 /* If disconnected_peer is next_hop, then send a trail teardown message through
206 * prev_hop in direction from destination to source. */
207 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_trail->next_hop,
210 my_identity = GDS_NEIGHBOURS_get_my_id ();
211 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity,
212 &remove_trail->prev_hop))
214 GDS_NEIGHBOURS_send_trail_teardown (&trail_id,
215 GDS_ROUTING_DEST_TO_SRC,
216 &remove_trail->prev_hop);
220 /* If disconnected_peer is prev_hop, then send a trail teardown through
221 * next_hop in direction from Source to Destination. */
222 if (0 == GNUNET_CRYPTO_cmp_peer_identity (&remove_trail->prev_hop,
225 my_identity = GDS_NEIGHBOURS_get_my_id ();
227 if (0 != GNUNET_CRYPTO_cmp_peer_identity (&my_identity,
228 &remove_trail->next_hop))
230 GDS_NEIGHBOURS_send_trail_teardown (&trail_id,
231 GDS_ROUTING_SRC_TO_DEST,
232 &remove_trail->next_hop);
236 GNUNET_assert (GNUNET_YES ==
237 GNUNET_CONTAINER_multihashmap_remove (routing_table,
240 GNUNET_free (remove_trail);
247 * Remove after using.
250 GDS_ROUTING_test_print (void)
252 struct GNUNET_CONTAINER_MultiHashMapIterator *iter;
253 struct RoutingTrail *trail;
254 struct GNUNET_PeerIdentity print_peer;
255 struct GNUNET_HashCode key_ret;
258 struct GNUNET_PeerIdentity my_identity = GDS_NEIGHBOURS_get_my_id();
259 print_peer = my_identity;
260 FPRINTF (stderr,_("\nSUPU ***PRINTING ROUTING TABLE ***** of =%s"),GNUNET_i2s(&print_peer));
261 iter =GNUNET_CONTAINER_multihashmap_iterator_create (routing_table);
262 for (i = 0; i < GNUNET_CONTAINER_multihashmap_size(routing_table); i++)
264 if(GNUNET_YES == GNUNET_CONTAINER_multihashmap_iterator_next (iter,
266 (const void **)&trail))
268 FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail->trail_id = %s"),
269 __FILE__, __func__,__LINE__, GNUNET_h2s(&trail->trail_id));
270 GNUNET_memcpy (&print_peer, &trail->next_hop, sizeof (struct GNUNET_PeerIdentity));
271 FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail->next_hop = %s"),
272 __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer));
273 GNUNET_memcpy (&print_peer, &trail->prev_hop, sizeof (struct GNUNET_PeerIdentity));
274 FPRINTF (stderr,_("\nSUPU %s, %s, %d, trail->prev_hop = %s"),
275 __FILE__, __func__,__LINE__, GNUNET_i2s(&print_peer));
282 * Remove every trail where peer is either next_hop or prev_hop. Also send a
283 * trail teardown message in direction of hop which is not disconnected.
284 * @param peer Peer identity. Trail containing this peer should be removed.
287 GDS_ROUTING_remove_trail_by_peer (const struct GNUNET_PeerIdentity *peer)
292 /* No entries in my routing table. */
293 if (0 == GNUNET_CONTAINER_multihashmap_size(routing_table))
296 ret = GNUNET_CONTAINER_multihashmap_iterate (routing_table,
297 &remove_matching_trails,
304 * Add a new entry in routing table
305 * @param new_trail_id
308 * @return #GNUNET_OK success
309 * #GNUNET_SYSERR in case new_trail_id already exists in the network
310 * but with different prev_hop/next_hop
313 GDS_ROUTING_add (const struct GNUNET_HashCode *new_trail_id,
314 const struct GNUNET_PeerIdentity *prev_hop,
315 const struct GNUNET_PeerIdentity *next_hop)
317 struct RoutingTrail *new_entry;
319 new_entry = GNUNET_new (struct RoutingTrail);
320 new_entry->trail_id = *new_trail_id;
321 new_entry->next_hop = *next_hop;
322 new_entry->prev_hop = *prev_hop;
324 // FIXME: this leaks memory if the put fails!
325 return GNUNET_CONTAINER_multihashmap_put (routing_table,
326 &new_entry->trail_id,
328 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
333 * Check if the size of routing table has crossed ROUTING_TABLE_THRESHOLD.
334 * It means that I don't have any more space in my routing table and I can not
335 * be part of any more trails till there is free space in my routing table.
336 * @return #GNUNET_YES, if threshold crossed else #GNUNET_NO.
339 GDS_ROUTING_threshold_reached (void)
341 return (GNUNET_CONTAINER_multihashmap_size(routing_table) >
342 ROUTING_TABLE_THRESHOLD) ? GNUNET_YES:GNUNET_NO;
347 * Initialize routing subsystem.
350 GDS_ROUTING_init (void)
352 routing_table = GNUNET_CONTAINER_multihashmap_create (ROUTING_TABLE_THRESHOLD * 4 / 3,
358 * Shutdown routing subsystem.
361 GDS_ROUTING_done (void)
363 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (routing_table));
364 GNUNET_CONTAINER_multihashmap_destroy (routing_table);
367 /* end of gnunet-service-xdht_routing.c */