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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 * Block group for filtering replies.
63 struct GNUNET_BLOCK_Group *bg;
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.
84 enum GNUNET_DHT_RouteOption options;
90 * Recent requests by time inserted.
92 static struct GNUNET_CONTAINER_Heap *recent_heap;
95 * Recently seen requests by key.
97 static struct GNUNET_CONTAINER_MultiHashMap *recent_map;
101 * Closure for the 'process' function.
103 struct ProcessContext
106 * Path of the original PUT
108 const struct GNUNET_PeerIdentity *put_path;
113 const struct GNUNET_PeerIdentity *get_path;
116 * Payload of the reply.
121 * Expiration time of the result.
123 struct GNUNET_TIME_Absolute expiration_time;
126 * Number of entries in @e put_path.
128 unsigned int put_path_length;
131 * Number of entries in @e get_path.
133 unsigned int get_path_length;
136 * Number of bytes in @e data.
143 enum GNUNET_BLOCK_Type type;
149 * Forward the result to the given peer if it matches the request.
151 * @param cls the `struct ProcessContext` with the result
152 * @param key the query
153 * @param value the `struct RecentRequest` with the request
154 * @return #GNUNET_OK (continue to iterate),
155 * #GNUNET_SYSERR if the result is malformed or type unsupported
159 const struct GNUNET_HashCode *key,
162 struct ProcessContext *pc = cls;
163 struct RecentRequest *rr = value;
164 enum GNUNET_BLOCK_EvaluationResult eval;
167 struct GNUNET_HashCode hc;
168 const struct GNUNET_HashCode *eval_key;
170 if ( (rr->type != GNUNET_BLOCK_TYPE_ANY) &&
171 (rr->type != pc->type) )
172 return GNUNET_OK; /* type missmatch */
174 if (0 != (rr->options & GNUNET_DHT_RO_RECORD_ROUTE))
176 gpl = pc->get_path_length;
177 ppl = pc->put_path_length;
184 if ( (0 != (rr->options & GNUNET_DHT_RO_FIND_PEER)) &&
185 (pc->type == GNUNET_BLOCK_TYPE_DHT_HELLO) )
187 /* key may not match HELLO, which is OK since
188 * the search is approximate. Still, the evaluation
189 * would fail since the match is not exact. So
190 * we fake it by changing the key to the actual PID ... */
191 GNUNET_BLOCK_get_key (GDS_block_context,
192 GNUNET_BLOCK_TYPE_DHT_HELLO,
203 = GNUNET_BLOCK_evaluate (GDS_block_context,
206 GNUNET_BLOCK_EO_NONE,
212 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
213 "Result for %s of type %d was evaluated as %d\n",
219 case GNUNET_BLOCK_EVALUATION_OK_MORE:
220 case GNUNET_BLOCK_EVALUATION_OK_LAST:
221 GNUNET_STATISTICS_update (GDS_stats,
223 ("# Good REPLIES matched against routing table"),
225 GDS_NEIGHBOURS_handle_reply (&rr->peer,
234 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
235 GNUNET_STATISTICS_update (GDS_stats,
237 ("# Duplicate REPLIES matched against routing table"),
240 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
241 GNUNET_STATISTICS_update (GDS_stats,
243 ("# Invalid REPLIES matched against routing table"),
245 return GNUNET_SYSERR;
246 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
247 GNUNET_STATISTICS_update (GDS_stats,
249 ("# Irrelevant REPLIES matched against routing table"),
252 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
255 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
258 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
259 GNUNET_STATISTICS_update (GDS_stats,
261 ("# Unsupported REPLIES matched against routing table"),
263 return GNUNET_SYSERR;
266 return GNUNET_SYSERR;
273 * Handle a reply (route to origin). Only forwards the reply back to
274 * other peers waiting for it. Does not do local caching or
275 * forwarding to local clients. Essentially calls
276 * GDS_NEIGHBOURS_handle_reply for all peers that sent us a matching
279 * @param cls NULL (why have it?)
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_BLOCK_group_destroy (recent_req->bg);
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 GNUNET_break (GNUNET_SYSERR !=
383 GNUNET_BLOCK_group_merge (in->bg,
387 return GNUNET_SYSERR;
392 * Add a new entry to our routing table.
394 * @param sender peer that originated the request
395 * @param type type of the block
396 * @param options options for processing
397 * @param key key for the content
398 * @param xquery extended query
399 * @param xquery_size number of bytes in @a xquery
400 * @param reply_bf bloomfilter to filter duplicates
401 * @param reply_bf_mutator mutator for @a reply_bf
404 GDS_ROUTING_add (const struct GNUNET_PeerIdentity *sender,
405 enum GNUNET_BLOCK_Type type,
406 struct GNUNET_BLOCK_Group *bg,
407 enum GNUNET_DHT_RouteOption options,
408 const struct GNUNET_HashCode *key,
412 struct RecentRequest *recent_req;
414 while (GNUNET_CONTAINER_heap_get_size (recent_heap) >= DHT_MAX_RECENT)
415 expire_oldest_entry ();
416 GNUNET_STATISTICS_update (GDS_stats,
417 gettext_noop ("# Entries added to routing table"),
420 recent_req = GNUNET_malloc (sizeof (struct RecentRequest) + xquery_size);
421 recent_req->peer = *sender;
422 recent_req->key = *key;
424 recent_req->type = type;
425 recent_req->options = options;
426 recent_req->xquery = &recent_req[1];
427 GNUNET_memcpy (&recent_req[1],
430 recent_req->xquery_size = xquery_size;
432 GNUNET_CONTAINER_multihashmap_get_multiple (recent_map,
437 GNUNET_STATISTICS_update (GDS_stats,
439 ("# DHT requests combined"),
443 recent_req->heap_node
444 = GNUNET_CONTAINER_heap_insert (recent_heap,
446 GNUNET_TIME_absolute_get ().abs_value_us);
447 GNUNET_CONTAINER_multihashmap_put (recent_map,
450 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
455 * Initialize routing subsystem.
460 recent_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
461 recent_map = GNUNET_CONTAINER_multihashmap_create (DHT_MAX_RECENT * 4 / 3, GNUNET_NO);
466 * Shutdown routing subsystem.
471 while (GNUNET_CONTAINER_heap_get_size (recent_heap) > 0)
472 expire_oldest_entry ();
473 GNUNET_assert (0 == GNUNET_CONTAINER_heap_get_size (recent_heap));
474 GNUNET_CONTAINER_heap_destroy (recent_heap);
476 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (recent_map));
477 GNUNET_CONTAINER_multihashmap_destroy (recent_map);
481 /* end of gnunet-service-dht_routing.c */