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22 * @file dht/gnunet-service-dht_routing.c
23 * @brief GNUnet DHT tracking of requests for routing replies
24 * @author Christian Grothoff
27 #include "gnunet-service-dht_neighbours.h"
28 #include "gnunet-service-dht_routing.h"
29 #include "gnunet-service-dht.h"
33 * Number of requests we track at most (for routing replies).
35 #define DHT_MAX_RECENT (1024 * 16)
39 * Information we keep about all recent GET requests
40 * so that we can route replies.
46 * The peer this request was received from.
48 struct GNUNET_PeerIdentity peer;
51 * Key of this request.
53 struct GNUNET_HashCode key;
56 * Position of this node in the min heap.
58 struct GNUNET_CONTAINER_HeapNode *heap_node;
61 * Bloomfilter for replies to drop.
63 struct GNUNET_CONTAINER_BloomFilter *reply_bf;
66 * Type of the requested block.
68 enum GNUNET_BLOCK_Type type;
71 * extended query (see gnunet_block_lib.h). Allocated at the
77 * Number of bytes in xquery.
82 * Mutator value for the reply_bf, see gnunet_block_lib.h
84 uint32_t reply_bf_mutator;
89 enum GNUNET_DHT_RouteOption options;
95 * Recent requests by time inserted.
97 static struct GNUNET_CONTAINER_Heap *recent_heap;
100 * Recently seen requests by key.
102 static struct GNUNET_CONTAINER_MultiHashMap *recent_map;
106 * Closure for the 'process' function.
108 struct ProcessContext
111 * Path of the original PUT
113 const struct GNUNET_PeerIdentity *put_path;
118 const struct GNUNET_PeerIdentity *get_path;
121 * Payload of the reply.
126 * Expiration time of the result.
128 struct GNUNET_TIME_Absolute expiration_time;
131 * Number of entries in 'put_path'.
133 unsigned int put_path_length;
136 * Number of entries in 'get_path'.
138 unsigned int get_path_length;
141 * Number of bytes in 'data'.
148 enum GNUNET_BLOCK_Type type;
154 * Forward the result to the given peer if it matches the request.
156 * @param cls the `struct ProcessContext` with the result
157 * @param key the query
158 * @param value the `struct RecentRequest` with the request
159 * @return #GNUNET_OK (continue to iterate),
160 * #GNUNET_SYSERR if the result is malformed or type unsupported
164 const struct GNUNET_HashCode *key,
167 struct ProcessContext *pc = cls;
168 struct RecentRequest *rr = value;
169 enum GNUNET_BLOCK_EvaluationResult eval;
172 struct GNUNET_HashCode hc;
173 const struct GNUNET_HashCode *eval_key;
175 if ( (rr->type != GNUNET_BLOCK_TYPE_ANY) &&
176 (rr->type != pc->type) )
177 return GNUNET_OK; /* type missmatch */
179 if (0 != (rr->options & GNUNET_DHT_RO_RECORD_ROUTE))
181 gpl = pc->get_path_length;
182 ppl = pc->put_path_length;
189 if ( (0 != (rr->options & GNUNET_DHT_RO_FIND_PEER)) &&
190 (pc->type == GNUNET_BLOCK_TYPE_DHT_HELLO) )
192 /* key may not match HELLO, which is OK since
193 * the search is approximate. Still, the evaluation
194 * would fail since the match is not exact. So
195 * we fake it by changing the key to the actual PID ... */
196 GNUNET_BLOCK_get_key (GDS_block_context,
197 GNUNET_BLOCK_TYPE_DHT_HELLO,
208 = GNUNET_BLOCK_evaluate (GDS_block_context,
210 GNUNET_BLOCK_EO_NONE,
213 rr->reply_bf_mutator,
220 case GNUNET_BLOCK_EVALUATION_OK_MORE:
221 case GNUNET_BLOCK_EVALUATION_OK_LAST:
222 GNUNET_STATISTICS_update (GDS_stats,
224 ("# Good REPLIES matched against routing table"),
226 GDS_NEIGHBOURS_handle_reply (&rr->peer, pc->type, pc->expiration_time, key,
227 ppl, pc->put_path, gpl, pc->get_path, pc->data,
230 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
231 GNUNET_STATISTICS_update (GDS_stats,
233 ("# Duplicate REPLIES matched against routing table"),
236 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
237 GNUNET_STATISTICS_update (GDS_stats,
239 ("# Invalid REPLIES matched against routing table"),
241 return GNUNET_SYSERR;
242 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
243 GNUNET_STATISTICS_update (GDS_stats,
245 ("# Irrelevant REPLIES matched against routing table"),
248 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
251 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
254 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
255 GNUNET_STATISTICS_update (GDS_stats,
257 ("# Unsupported REPLIES matched against routing table"),
259 return GNUNET_SYSERR;
262 return GNUNET_SYSERR;
269 * Handle a reply (route to origin). Only forwards the reply back to
270 * other peers waiting for it. Does not do local caching or
271 * forwarding to local clients. Essentially calls
272 * GDS_NEIGHBOURS_handle_reply for all peers that sent us a matching
275 * @param type type of the block
276 * @param expiration_time when does the content expire
277 * @param key key for the content
278 * @param put_path_length number of entries in put_path
279 * @param put_path peers the original PUT traversed (if tracked)
280 * @param get_path_length number of entries in get_path
281 * @param get_path peers this reply has traversed so far (if tracked)
282 * @param data payload of the reply
283 * @param data_size number of bytes in data
286 GDS_ROUTING_process (void *cls,
287 enum GNUNET_BLOCK_Type type,
288 struct GNUNET_TIME_Absolute expiration_time,
289 const struct GNUNET_HashCode *key,
290 unsigned int put_path_length,
291 const struct GNUNET_PeerIdentity *put_path,
292 unsigned int get_path_length,
293 const struct GNUNET_PeerIdentity *get_path,
297 struct ProcessContext pc;
300 pc.expiration_time = expiration_time;
301 pc.put_path_length = put_path_length;
302 pc.put_path = put_path;
303 pc.get_path_length = get_path_length;
304 pc.get_path = get_path;
306 pc.data_size = data_size;
309 /* Some apps might have an 'empty' reply as a valid reply; however,
310 'process' will call GNUNET_BLOCK_evaluate' which treats a 'NULL'
311 reply as request-validation (but we need response-validation).
312 So we set 'data' to a 0-byte non-NULL value just to be sure */
313 GNUNET_break (0 == data_size);
315 pc.data = ""; /* something not null */
317 GNUNET_CONTAINER_multihashmap_get_multiple (recent_map,
325 * Remove the oldest entry from the DHT routing table. Must only
326 * be called if it is known that there is at least one entry
327 * in the heap and hashmap.
330 expire_oldest_entry ()
332 struct RecentRequest *recent_req;
334 GNUNET_STATISTICS_update (GDS_stats,
336 ("# Entries removed from routing table"), 1,
338 recent_req = GNUNET_CONTAINER_heap_peek (recent_heap);
339 GNUNET_assert (recent_req != NULL);
340 GNUNET_CONTAINER_heap_remove_node (recent_req->heap_node);
341 GNUNET_CONTAINER_bloomfilter_free (recent_req->reply_bf);
342 GNUNET_assert (GNUNET_YES ==
343 GNUNET_CONTAINER_multihashmap_remove (recent_map,
346 GNUNET_free (recent_req);
351 * Try to combine multiple recent requests for the same value
352 * (if they come from the same peer).
354 * @param cls the new 'struct RecentRequest' (to discard upon successful combination)
355 * @param key the query
356 * @param value the existing 'struct RecentRequest' (to update upon successful combination)
357 * @return #GNUNET_OK (continue to iterate),
358 * #GNUNET_SYSERR if the request was successfully combined
361 try_combine_recent (void *cls,
362 const struct GNUNET_HashCode *key,
365 struct RecentRequest *in = cls;
366 struct RecentRequest *rr = value;
368 if ( (0 != memcmp (&in->peer,
370 sizeof (struct GNUNET_PeerIdentity))) ||
371 (in->type != rr->type) ||
372 (in->xquery_size != rr->xquery_size) ||
373 (0 != memcmp (in->xquery,
377 if (in->reply_bf_mutator != rr->reply_bf_mutator)
379 rr->reply_bf_mutator = in->reply_bf_mutator;
380 GNUNET_CONTAINER_bloomfilter_free (rr->reply_bf);
381 rr->reply_bf = in->reply_bf;
385 GNUNET_CONTAINER_bloomfilter_or2 (rr->reply_bf,
387 GNUNET_CONTAINER_bloomfilter_free (in->reply_bf);
390 return GNUNET_SYSERR;
395 * Add a new entry to our routing table.
397 * @param sender peer that originated the request
398 * @param type type of the block
399 * @param options options for processing
400 * @param key key for the content
401 * @param xquery extended query
402 * @param xquery_size number of bytes in @a xquery
403 * @param reply_bf bloomfilter to filter duplicates
404 * @param reply_bf_mutator mutator for @a reply_bf
407 GDS_ROUTING_add (const struct GNUNET_PeerIdentity *sender,
408 enum GNUNET_BLOCK_Type type,
409 enum GNUNET_DHT_RouteOption options,
410 const struct GNUNET_HashCode *key,
413 const struct GNUNET_CONTAINER_BloomFilter *reply_bf,
414 uint32_t reply_bf_mutator)
416 struct RecentRequest *recent_req;
418 while (GNUNET_CONTAINER_heap_get_size (recent_heap) >= DHT_MAX_RECENT)
419 expire_oldest_entry ();
420 GNUNET_STATISTICS_update (GDS_stats,
421 gettext_noop ("# Entries added to routing table"),
423 recent_req = GNUNET_malloc (sizeof (struct RecentRequest) + xquery_size);
424 recent_req->peer = *sender;
425 recent_req->key = *key;
426 recent_req->reply_bf = GNUNET_CONTAINER_bloomfilter_copy (reply_bf);
427 recent_req->type = type;
428 recent_req->options = options;
429 recent_req->xquery = &recent_req[1];
430 GNUNET_memcpy (&recent_req[1], xquery, xquery_size);
431 recent_req->xquery_size = xquery_size;
432 recent_req->reply_bf_mutator = reply_bf_mutator;
434 GNUNET_CONTAINER_multihashmap_get_multiple (recent_map,
439 GNUNET_STATISTICS_update (GDS_stats,
441 ("# DHT requests combined"),
445 recent_req->heap_node =
446 GNUNET_CONTAINER_heap_insert (recent_heap, recent_req,
447 GNUNET_TIME_absolute_get ().abs_value_us);
448 GNUNET_CONTAINER_multihashmap_put (recent_map, key, recent_req,
449 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
456 * Initialize routing subsystem.
461 recent_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
462 recent_map = GNUNET_CONTAINER_multihashmap_create (DHT_MAX_RECENT * 4 / 3, GNUNET_NO);
467 * Shutdown routing subsystem.
472 while (GNUNET_CONTAINER_heap_get_size (recent_heap) > 0)
473 expire_oldest_entry ();
474 GNUNET_assert (0 == GNUNET_CONTAINER_heap_get_size (recent_heap));
475 GNUNET_CONTAINER_heap_destroy (recent_heap);
477 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (recent_map));
478 GNUNET_CONTAINER_multihashmap_destroy (recent_map);
482 /* end of gnunet-service-dht_routing.c */