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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 @e put_path.
133 unsigned int put_path_length;
136 * Number of entries in @e get_path.
138 unsigned int get_path_length;
141 * Number of bytes in @e 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,
235 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
236 GNUNET_STATISTICS_update (GDS_stats,
238 ("# Duplicate REPLIES matched against routing table"),
241 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
242 GNUNET_STATISTICS_update (GDS_stats,
244 ("# Invalid REPLIES matched against routing table"),
246 return GNUNET_SYSERR;
247 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
248 GNUNET_STATISTICS_update (GDS_stats,
250 ("# Irrelevant REPLIES matched against routing table"),
253 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
256 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
259 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
260 GNUNET_STATISTICS_update (GDS_stats,
262 ("# Unsupported REPLIES matched against routing table"),
264 return GNUNET_SYSERR;
267 return GNUNET_SYSERR;
274 * Handle a reply (route to origin). Only forwards the reply back to
275 * other peers waiting for it. Does not do local caching or
276 * forwarding to local clients. Essentially calls
277 * GDS_NEIGHBOURS_handle_reply for all peers that sent us a matching
280 * @param type type of the block
281 * @param expiration_time when does the content expire
282 * @param key key for the content
283 * @param put_path_length number of entries in @a put_path
284 * @param put_path peers the original PUT traversed (if tracked)
285 * @param get_path_length number of entries in @a get_path
286 * @param get_path peers this reply has traversed so far (if tracked)
287 * @param data payload of the reply
288 * @param data_size number of bytes in data
291 GDS_ROUTING_process (void *cls,
292 enum GNUNET_BLOCK_Type type,
293 struct GNUNET_TIME_Absolute expiration_time,
294 const struct GNUNET_HashCode *key,
295 unsigned int put_path_length,
296 const struct GNUNET_PeerIdentity *put_path,
297 unsigned int get_path_length,
298 const struct GNUNET_PeerIdentity *get_path,
302 struct ProcessContext pc;
305 pc.expiration_time = expiration_time;
306 pc.put_path_length = put_path_length;
307 pc.put_path = put_path;
308 pc.get_path_length = get_path_length;
309 pc.get_path = get_path;
311 pc.data_size = data_size;
314 /* Some apps might have an 'empty' reply as a valid reply; however,
315 'process' will call GNUNET_BLOCK_evaluate' which treats a 'NULL'
316 reply as request-validation (but we need response-validation).
317 So we set 'data' to a 0-byte non-NULL value just to be sure */
318 GNUNET_break (0 == data_size);
320 pc.data = ""; /* something not null */
322 GNUNET_CONTAINER_multihashmap_get_multiple (recent_map,
330 * Remove the oldest entry from the DHT routing table. Must only
331 * be called if it is known that there is at least one entry
332 * in the heap and hashmap.
335 expire_oldest_entry ()
337 struct RecentRequest *recent_req;
339 GNUNET_STATISTICS_update (GDS_stats,
341 ("# Entries removed from routing table"), 1,
343 recent_req = GNUNET_CONTAINER_heap_peek (recent_heap);
344 GNUNET_assert (recent_req != NULL);
345 GNUNET_CONTAINER_heap_remove_node (recent_req->heap_node);
346 GNUNET_CONTAINER_bloomfilter_free (recent_req->reply_bf);
347 GNUNET_assert (GNUNET_YES ==
348 GNUNET_CONTAINER_multihashmap_remove (recent_map,
351 GNUNET_free (recent_req);
356 * Try to combine multiple recent requests for the same value
357 * (if they come from the same peer).
359 * @param cls the new 'struct RecentRequest' (to discard upon successful combination)
360 * @param key the query
361 * @param value the existing 'struct RecentRequest' (to update upon successful combination)
362 * @return #GNUNET_OK (continue to iterate),
363 * #GNUNET_SYSERR if the request was successfully combined
366 try_combine_recent (void *cls,
367 const struct GNUNET_HashCode *key,
370 struct RecentRequest *in = cls;
371 struct RecentRequest *rr = value;
373 if ( (0 != memcmp (&in->peer,
375 sizeof (struct GNUNET_PeerIdentity))) ||
376 (in->type != rr->type) ||
377 (in->xquery_size != rr->xquery_size) ||
378 (0 != memcmp (in->xquery,
382 if (in->reply_bf_mutator != rr->reply_bf_mutator)
384 rr->reply_bf_mutator = in->reply_bf_mutator;
385 GNUNET_CONTAINER_bloomfilter_free (rr->reply_bf);
386 rr->reply_bf = in->reply_bf;
390 GNUNET_CONTAINER_bloomfilter_or2 (rr->reply_bf,
392 GNUNET_CONTAINER_bloomfilter_free (in->reply_bf);
395 return GNUNET_SYSERR;
400 * Add a new entry to our routing table.
402 * @param sender peer that originated the request
403 * @param type type of the block
404 * @param options options for processing
405 * @param key key for the content
406 * @param xquery extended query
407 * @param xquery_size number of bytes in @a xquery
408 * @param reply_bf bloomfilter to filter duplicates
409 * @param reply_bf_mutator mutator for @a reply_bf
412 GDS_ROUTING_add (const struct GNUNET_PeerIdentity *sender,
413 enum GNUNET_BLOCK_Type type,
414 enum GNUNET_DHT_RouteOption options,
415 const struct GNUNET_HashCode *key,
418 const struct GNUNET_CONTAINER_BloomFilter *reply_bf,
419 uint32_t reply_bf_mutator)
421 struct RecentRequest *recent_req;
423 while (GNUNET_CONTAINER_heap_get_size (recent_heap) >= DHT_MAX_RECENT)
424 expire_oldest_entry ();
425 GNUNET_STATISTICS_update (GDS_stats,
426 gettext_noop ("# Entries added to routing table"),
428 recent_req = GNUNET_malloc (sizeof (struct RecentRequest) + xquery_size);
429 recent_req->peer = *sender;
430 recent_req->key = *key;
431 recent_req->reply_bf = GNUNET_CONTAINER_bloomfilter_copy (reply_bf);
432 recent_req->type = type;
433 recent_req->options = options;
434 recent_req->xquery = &recent_req[1];
435 GNUNET_memcpy (&recent_req[1], xquery, xquery_size);
436 recent_req->xquery_size = xquery_size;
437 recent_req->reply_bf_mutator = reply_bf_mutator;
439 GNUNET_CONTAINER_multihashmap_get_multiple (recent_map,
444 GNUNET_STATISTICS_update (GDS_stats,
446 ("# DHT requests combined"),
450 recent_req->heap_node =
451 GNUNET_CONTAINER_heap_insert (recent_heap, recent_req,
452 GNUNET_TIME_absolute_get ().abs_value_us);
453 GNUNET_CONTAINER_multihashmap_put (recent_map, key, recent_req,
454 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
461 * Initialize routing subsystem.
466 recent_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
467 recent_map = GNUNET_CONTAINER_multihashmap_create (DHT_MAX_RECENT * 4 / 3, GNUNET_NO);
472 * Shutdown routing subsystem.
477 while (GNUNET_CONTAINER_heap_get_size (recent_heap) > 0)
478 expire_oldest_entry ();
479 GNUNET_assert (0 == GNUNET_CONTAINER_heap_get_size (recent_heap));
480 GNUNET_CONTAINER_heap_destroy (recent_heap);
482 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (recent_map));
483 GNUNET_CONTAINER_multihashmap_destroy (recent_map);
487 /* end of gnunet-service-dht_routing.c */