2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
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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
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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.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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22 * @file dht/gnunet-service-dht_clients.c
23 * @brief GNUnet DHT service's client management code
24 * @author Christian Grothoff
25 * @author Nathan Evans
29 #include "gnunet_constants.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_statistics_service.h"
32 #include "gnunet-service-dht.h"
33 #include "gnunet-service-dht_clients.h"
34 #include "gnunet-service-dht_datacache.h"
35 #include "gnunet-service-dht_neighbours.h"
40 * Should routing details be logged to stderr (for debugging)?
42 #define LOG_ROUTE_DETAILS_STDERR GNUNET_NO
44 #define LOG(kind,...) GNUNET_log_from (kind, "dht-clients",__VA_ARGS__)
47 * Linked list of messages to send to clients.
52 * Pointer to next item in the list
54 struct PendingMessage *next;
57 * Pointer to previous item in the list
59 struct PendingMessage *prev;
62 * Actual message to be sent, allocated at the end of the struct:
63 * // msg = (cast) &pm[1];
64 * // memcpy (&pm[1], data, len);
66 const struct GNUNET_MessageHeader *msg;
72 * Struct containing information about a client,
73 * handle to connect to it, and any pending messages
74 * that need to be sent to it.
79 * Linked list of active clients
81 struct ClientList *next;
84 * Linked list of active clients
86 struct ClientList *prev;
89 * The handle to this client
91 struct GNUNET_SERVER_Client *client_handle;
94 * Handle to the current transmission request, NULL
97 struct GNUNET_SERVER_TransmitHandle *transmit_handle;
100 * Linked list of pending messages for this client
102 struct PendingMessage *pending_head;
105 * Tail of linked list of pending messages for this client
107 struct PendingMessage *pending_tail;
113 * Entry in the DHT routing table for a client's GET request.
115 struct ClientQueryRecord
119 * The key this request was about
121 struct GNUNET_HashCode key;
124 * Client responsible for the request.
126 struct ClientList *client;
129 * Extended query (see gnunet_block_lib.h), allocated at the end of this struct.
134 * Replies we have already seen for this request.
136 struct GNUNET_HashCode *seen_replies;
139 * Pointer to this nodes heap location in the retry-heap (for fast removal)
141 struct GNUNET_CONTAINER_HeapNode *hnode;
144 * What's the delay between re-try operations that we currently use for this
147 struct GNUNET_TIME_Relative retry_frequency;
150 * What's the next time we should re-try this request?
152 struct GNUNET_TIME_Absolute retry_time;
155 * The unique identifier of this request
160 * Number of bytes in xquery.
165 * Number of entries in 'seen_replies'.
167 unsigned int seen_replies_count;
170 * Desired replication level
172 uint32_t replication;
175 * Any message options for this request
177 uint32_t msg_options;
180 * The type for the data for the GET request.
182 enum GNUNET_BLOCK_Type type;
188 * Struct containing paremeters of monitoring requests.
190 struct ClientMonitorRecord
194 * Next element in DLL.
196 struct ClientMonitorRecord *next;
199 * Previous element in DLL.
201 struct ClientMonitorRecord *prev;
204 * Type of blocks that are of interest
206 enum GNUNET_BLOCK_Type type;
209 * Key of data of interest, NULL for all.
211 struct GNUNET_HashCode *key;
214 * Flag whether to notify about GET messages.
219 * Flag whether to notify about GET_REPONSE messages.
224 * Flag whether to notify about PUT messages.
229 * Client to notify of these requests.
231 struct ClientList *client;
236 * List of active clients.
238 static struct ClientList *client_head;
241 * List of active clients.
243 static struct ClientList *client_tail;
246 * List of active monitoring requests.
248 static struct ClientMonitorRecord *monitor_head;
251 * List of active monitoring requests.
253 static struct ClientMonitorRecord *monitor_tail;
256 * Hashmap for fast key based lookup, maps keys to 'struct ClientQueryRecord' entries.
258 static struct GNUNET_CONTAINER_MultiHashMap *forward_map;
261 * Heap with all of our client's request, sorted by retry time (earliest on top).
263 static struct GNUNET_CONTAINER_Heap *retry_heap;
266 * Task that re-transmits requests (using retry_heap).
268 static GNUNET_SCHEDULER_TaskIdentifier retry_task;
272 * Task run to check for messages that need to be sent to a client.
274 * @param client a ClientList, containing the client and any messages to be sent to it
277 process_pending_messages (struct ClientList *client);
281 * Add a PendingMessage to the clients list of messages to be sent
283 * @param client the active client to send the message to
284 * @param pending_message the actual message to send
287 add_pending_message (struct ClientList *client,
288 struct PendingMessage *pending_message)
290 GNUNET_CONTAINER_DLL_insert_tail (client->pending_head, client->pending_tail,
292 process_pending_messages (client);
297 * Find a client if it exists, add it otherwise.
299 * @param client the server handle to the client
301 * @return the client if found, a new client otherwise
303 static struct ClientList *
304 find_active_client (struct GNUNET_SERVER_Client *client)
306 struct ClientList *pos = client_head;
307 struct ClientList *ret;
311 if (pos->client_handle == client)
315 ret = GNUNET_malloc (sizeof (struct ClientList));
316 ret->client_handle = client;
317 GNUNET_CONTAINER_DLL_insert (client_head, client_tail, ret);
323 * Iterator over hash map entries that frees all entries
324 * associated with the given client.
326 * @param cls client to search for in source routes
327 * @param key current key code (ignored)
328 * @param value value in the hash map, a ClientQueryRecord
329 * @return GNUNET_YES (we should continue to iterate)
332 remove_client_records (void *cls, const struct GNUNET_HashCode * key, void *value)
334 struct ClientList *client = cls;
335 struct ClientQueryRecord *record = value;
337 if (record->client != client)
339 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
340 "Removing client %p's record for key %s\n", client,
342 GNUNET_assert (GNUNET_YES ==
343 GNUNET_CONTAINER_multihashmap_remove (forward_map, key,
345 if (NULL != record->hnode)
346 GNUNET_CONTAINER_heap_remove_node (record->hnode);
347 GNUNET_array_grow (record->seen_replies, record->seen_replies_count, 0);
348 GNUNET_free (record);
354 * Functions with this signature are called whenever a client
355 * is disconnected on the network level.
357 * @param cls closure (NULL for dht)
358 * @param client identification of the client; NULL
359 * for the last call when the server is destroyed
362 handle_client_disconnect (void *cls, struct GNUNET_SERVER_Client *client)
364 struct ClientList *pos;
365 struct PendingMessage *reply;
366 struct ClientMonitorRecord *monitor;
368 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Local client %p disconnects\n", client);
369 pos = find_active_client (client);
370 GNUNET_CONTAINER_DLL_remove (client_head, client_tail, pos);
371 if (pos->transmit_handle != NULL)
372 GNUNET_SERVER_notify_transmit_ready_cancel (pos->transmit_handle);
373 while (NULL != (reply = pos->pending_head))
375 GNUNET_CONTAINER_DLL_remove (pos->pending_head, pos->pending_tail, reply);
378 monitor = monitor_head;
379 while (NULL != monitor)
381 if (monitor->client == pos)
383 struct ClientMonitorRecord *next;
385 GNUNET_free_non_null (monitor->key);
386 next = monitor->next;
387 GNUNET_CONTAINER_DLL_remove (monitor_head, monitor_tail, monitor);
388 GNUNET_free (monitor);
392 monitor = monitor->next;
394 GNUNET_CONTAINER_multihashmap_iterate (forward_map, &remove_client_records,
401 * Route the given request via the DHT. This includes updating
402 * the bloom filter and retransmission times, building the P2P
403 * message and initiating the routing operation.
406 transmit_request (struct ClientQueryRecord *cqr)
408 int32_t reply_bf_mutator;
409 struct GNUNET_CONTAINER_BloomFilter *reply_bf;
410 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
412 GNUNET_STATISTICS_update (GDS_stats,
414 ("# GET requests from clients injected"), 1,
417 (int32_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
420 GNUNET_BLOCK_construct_bloomfilter (reply_bf_mutator, cqr->seen_replies,
421 cqr->seen_replies_count);
423 GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE,
424 GNUNET_CONSTANTS_BLOOMFILTER_K);
425 LOG (GNUNET_ERROR_TYPE_DEBUG,
426 "Initiating GET for %s, replication %u, already have %u replies\n",
427 GNUNET_h2s(&cqr->key), cqr->replication, cqr->seen_replies_count);
428 GDS_NEIGHBOURS_handle_get (cqr->type, cqr->msg_options, cqr->replication,
430 &cqr->key, cqr->xquery, cqr->xquery_size, reply_bf,
431 reply_bf_mutator, peer_bf);
432 GNUNET_CONTAINER_bloomfilter_free (reply_bf);
433 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
435 /* exponential back-off for retries.
436 * max GNUNET_TIME_STD_EXPONENTIAL_BACKOFF_THRESHOLD (15 min) */
437 cqr->retry_frequency = GNUNET_TIME_STD_BACKOFF (cqr->retry_frequency);
438 cqr->retry_time = GNUNET_TIME_relative_to_absolute (cqr->retry_frequency);
443 * Task that looks at the 'retry_heap' and transmits all of the requests
444 * on the heap that are ready for transmission. Then re-schedules
445 * itself (unless the heap is empty).
448 * @param tc scheduler context
451 transmit_next_request_task (void *cls,
452 const struct GNUNET_SCHEDULER_TaskContext *tc)
454 struct ClientQueryRecord *cqr;
455 struct GNUNET_TIME_Relative delay;
457 retry_task = GNUNET_SCHEDULER_NO_TASK;
458 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
460 while (NULL != (cqr = GNUNET_CONTAINER_heap_remove_root (retry_heap)))
463 delay = GNUNET_TIME_absolute_get_remaining (cqr->retry_time);
464 if (delay.rel_value > 0)
467 GNUNET_CONTAINER_heap_insert (retry_heap, cqr,
468 cqr->retry_time.abs_value);
470 GNUNET_SCHEDULER_add_delayed (delay, &transmit_next_request_task,
474 transmit_request (cqr);
476 GNUNET_CONTAINER_heap_insert (retry_heap, cqr,
477 cqr->retry_time.abs_value);
483 * Handler for PUT messages.
485 * @param cls closure for the service
486 * @param client the client we received this message from
487 * @param message the actual message received
490 handle_dht_local_put (void *cls, struct GNUNET_SERVER_Client *client,
491 const struct GNUNET_MessageHeader *message)
493 const struct GNUNET_DHT_ClientPutMessage *dht_msg;
494 struct GNUNET_CONTAINER_BloomFilter *peer_bf;
496 struct PendingMessage *pm;
497 struct GNUNET_DHT_ClientPutConfirmationMessage *conf;
499 size = ntohs (message->size);
500 if (size < sizeof (struct GNUNET_DHT_ClientPutMessage))
503 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
506 GNUNET_STATISTICS_update (GDS_stats,
508 ("# PUT requests received from clients"), 1,
510 dht_msg = (const struct GNUNET_DHT_ClientPutMessage *) message;
511 /* give to local clients */
512 LOG (GNUNET_ERROR_TYPE_DEBUG,
513 "Handling local PUT of %u-bytes for query %s\n",
514 size - sizeof (struct GNUNET_DHT_ClientPutMessage),
515 GNUNET_h2s (&dht_msg->key));
516 GDS_CLIENTS_handle_reply (GNUNET_TIME_absolute_ntoh (dht_msg->expiration),
517 &dht_msg->key, 0, NULL, 0, NULL,
518 ntohl (dht_msg->type),
519 size - sizeof (struct GNUNET_DHT_ClientPutMessage),
522 GDS_DATACACHE_handle_put (GNUNET_TIME_absolute_ntoh (dht_msg->expiration),
523 &dht_msg->key, 0, NULL, ntohl (dht_msg->type),
524 size - sizeof (struct GNUNET_DHT_ClientPutMessage),
526 /* route to other peers */
528 GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE,
529 GNUNET_CONSTANTS_BLOOMFILTER_K);
530 GDS_NEIGHBOURS_handle_put (ntohl (dht_msg->type), ntohl (dht_msg->options),
531 ntohl (dht_msg->desired_replication_level),
532 GNUNET_TIME_absolute_ntoh (dht_msg->expiration),
534 peer_bf, &dht_msg->key, 0, NULL, &dht_msg[1],
536 sizeof (struct GNUNET_DHT_ClientPutMessage));
537 GDS_CLIENTS_process_put (ntohl (dht_msg->options),
538 ntohl (dht_msg->type),
540 ntohl (dht_msg->desired_replication_level),
542 GDS_NEIGHBOURS_get_id(),
543 GNUNET_TIME_absolute_ntoh (dht_msg->expiration),
546 size - sizeof (struct GNUNET_DHT_ClientPutMessage));
547 GNUNET_CONTAINER_bloomfilter_free (peer_bf);
548 pm = GNUNET_malloc (sizeof (struct PendingMessage) +
549 sizeof (struct GNUNET_DHT_ClientPutConfirmationMessage));
550 conf = (struct GNUNET_DHT_ClientPutConfirmationMessage *) &pm[1];
551 conf->header.size = htons (sizeof (struct GNUNET_DHT_ClientPutConfirmationMessage));
552 conf->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CLIENT_PUT_OK);
553 conf->reserved = htonl (0);
554 conf->unique_id = dht_msg->unique_id;
555 pm->msg = &conf->header;
556 add_pending_message (find_active_client (client), pm);
557 GNUNET_SERVER_receive_done (client, GNUNET_OK);
562 * Handler for DHT GET messages from the client.
564 * @param cls closure for the service
565 * @param client the client we received this message from
566 * @param message the actual message received
569 handle_dht_local_get (void *cls, struct GNUNET_SERVER_Client *client,
570 const struct GNUNET_MessageHeader *message)
572 const struct GNUNET_DHT_ClientGetMessage *get;
573 struct ClientQueryRecord *cqr;
578 size = ntohs (message->size);
579 if (size < sizeof (struct GNUNET_DHT_ClientGetMessage))
582 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
585 xquery_size = size - sizeof (struct GNUNET_DHT_ClientGetMessage);
586 get = (const struct GNUNET_DHT_ClientGetMessage *) message;
587 xquery = (const char *) &get[1];
588 GNUNET_STATISTICS_update (GDS_stats,
590 ("# GET requests received from clients"), 1,
592 LOG (GNUNET_ERROR_TYPE_DEBUG,
593 "Received GET request for %s from local client %p, xq: %.*s\n",
594 GNUNET_h2s (&get->key), client, xquery_size, xquery);
596 if (LOG_ROUTE_DETAILS_STDERR)
599 "XDHT CLIENT-GET %s @ %u\n",
600 GNUNET_h2s (&get->key),
605 cqr = GNUNET_malloc (sizeof (struct ClientQueryRecord) + xquery_size);
607 cqr->client = find_active_client (client);
608 cqr->xquery = (void *) &cqr[1];
609 memcpy (&cqr[1], xquery, xquery_size);
610 cqr->hnode = GNUNET_CONTAINER_heap_insert (retry_heap, cqr, 0);
611 cqr->retry_frequency = GNUNET_TIME_UNIT_SECONDS;
612 cqr->retry_time = GNUNET_TIME_absolute_get ();
613 cqr->unique_id = get->unique_id;
614 cqr->xquery_size = xquery_size;
615 cqr->replication = ntohl (get->desired_replication_level);
616 cqr->msg_options = ntohl (get->options);
617 cqr->type = ntohl (get->type);
618 // FIXME use cqr->key, set multihashmap create to GNUNET_YES
619 GNUNET_CONTAINER_multihashmap_put (forward_map, &get->key, cqr,
620 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE);
621 GDS_CLIENTS_process_get (ntohl (get->options),
624 ntohl (get->desired_replication_level),
626 GDS_NEIGHBOURS_get_id(),
628 /* start remote requests */
629 if (GNUNET_SCHEDULER_NO_TASK != retry_task)
630 GNUNET_SCHEDULER_cancel (retry_task);
631 retry_task = GNUNET_SCHEDULER_add_now (&transmit_next_request_task, NULL);
632 /* perform local lookup */
633 GDS_DATACACHE_handle_get (&get->key, cqr->type, cqr->xquery, xquery_size,
635 GNUNET_SERVER_receive_done (client, GNUNET_OK);
640 * Closure for 'find_by_unique_id'.
642 struct FindByUniqueIdContext
645 * Where to store the result, if found.
647 struct ClientQueryRecord *cqr;
654 * Function called for each existing DHT record for the given
655 * query. Checks if it matches the UID given in the closure
656 * and if so returns the entry as a result.
658 * @param cls the search context
659 * @param key query for the lookup (not used)
660 * @param value the 'struct ClientQueryRecord'
661 * @return GNUNET_YES to continue iteration (result not yet found)
664 find_by_unique_id (void *cls,
665 const struct GNUNET_HashCode *key,
668 struct FindByUniqueIdContext *fui_ctx = cls;
669 struct ClientQueryRecord *cqr = value;
671 if (cqr->unique_id != fui_ctx->unique_id)
679 * Handler for "GET result seen" messages from the client.
681 * @param cls closure for the service
682 * @param client the client we received this message from
683 * @param message the actual message received
686 handle_dht_local_get_result_seen (void *cls, struct GNUNET_SERVER_Client *client,
687 const struct GNUNET_MessageHeader *message)
689 const struct GNUNET_DHT_ClientGetResultSeenMessage *seen;
691 unsigned int hash_count;
692 unsigned int old_count;
693 const struct GNUNET_HashCode *hc;
694 struct FindByUniqueIdContext fui_ctx;
695 struct ClientQueryRecord *cqr;
697 size = ntohs (message->size);
698 if (size < sizeof (struct GNUNET_DHT_ClientGetResultSeenMessage))
701 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
704 seen = (const struct GNUNET_DHT_ClientGetResultSeenMessage *) message;
705 hash_count = (size - sizeof (struct GNUNET_DHT_ClientGetResultSeenMessage)) / sizeof (struct GNUNET_HashCode);
706 if (size != sizeof (struct GNUNET_DHT_ClientGetResultSeenMessage) + hash_count * sizeof (struct GNUNET_HashCode))
709 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
712 hc = (const struct GNUNET_HashCode*) &seen[1];
713 fui_ctx.unique_id = seen->unique_id;
715 GNUNET_CONTAINER_multihashmap_get_multiple (forward_map,
719 if (NULL == (cqr = fui_ctx.cqr))
722 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
725 /* finally, update 'seen' list */
726 old_count = cqr->seen_replies_count;
727 GNUNET_array_grow (cqr->seen_replies,
728 cqr->seen_replies_count,
729 cqr->seen_replies_count + hash_count);
730 memcpy (&cqr->seen_replies[old_count],
732 sizeof (struct GNUNET_HashCode) * hash_count);
737 * Closure for 'remove_by_unique_id'.
739 struct RemoveByUniqueIdContext
742 * Client that issued the removal request.
744 struct ClientList *client;
747 * Unique ID of the request.
754 * Iterator over hash map entries that frees all entries
755 * that match the given client and unique ID.
757 * @param cls unique ID and client to search for in source routes
758 * @param key current key code
759 * @param value value in the hash map, a ClientQueryRecord
760 * @return GNUNET_YES (we should continue to iterate)
763 remove_by_unique_id (void *cls, const struct GNUNET_HashCode * key, void *value)
765 const struct RemoveByUniqueIdContext *ctx = cls;
766 struct ClientQueryRecord *record = value;
768 if (record->unique_id != ctx->unique_id)
770 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
771 "Removing client %p's record for key %s (by unique id)\n",
772 ctx->client->client_handle, GNUNET_h2s (key));
773 return remove_client_records (ctx->client, key, record);
778 * Handler for any generic DHT stop messages, calls the appropriate handler
779 * depending on message type (if processed locally)
781 * @param cls closure for the service
782 * @param client the client we received this message from
783 * @param message the actual message received
787 handle_dht_local_get_stop (void *cls, struct GNUNET_SERVER_Client *client,
788 const struct GNUNET_MessageHeader *message)
790 const struct GNUNET_DHT_ClientGetStopMessage *dht_stop_msg =
791 (const struct GNUNET_DHT_ClientGetStopMessage *) message;
792 struct RemoveByUniqueIdContext ctx;
794 GNUNET_STATISTICS_update (GDS_stats,
796 ("# GET STOP requests received from clients"), 1,
798 LOG (GNUNET_ERROR_TYPE_DEBUG,
799 "Received GET STOP request for %s from local client %p\n",
800 client, GNUNET_h2s (&dht_stop_msg->key));
801 ctx.client = find_active_client (client);
802 ctx.unique_id = dht_stop_msg->unique_id;
803 GNUNET_CONTAINER_multihashmap_get_multiple (forward_map, &dht_stop_msg->key,
804 &remove_by_unique_id, &ctx);
805 GNUNET_SERVER_receive_done (client, GNUNET_OK);
810 * Handler for monitor start messages
812 * @param cls closure for the service
813 * @param client the client we received this message from
814 * @param message the actual message received
818 handle_dht_local_monitor (void *cls, struct GNUNET_SERVER_Client *client,
819 const struct GNUNET_MessageHeader *message)
821 struct ClientMonitorRecord *r;
822 const struct GNUNET_DHT_MonitorStartStopMessage *msg;
824 msg = (struct GNUNET_DHT_MonitorStartStopMessage *) message;
825 r = GNUNET_malloc (sizeof(struct ClientMonitorRecord));
827 r->client = find_active_client(client);
828 r->type = ntohl(msg->type);
829 r->get = ntohs(msg->get);
830 r->get_resp = ntohs(msg->get_resp);
831 r->put = ntohs(msg->put);
832 if (0 == ntohs(msg->filter_key))
836 r->key = GNUNET_malloc (sizeof (struct GNUNET_HashCode));
837 memcpy (r->key, &msg->key, sizeof (struct GNUNET_HashCode));
839 GNUNET_CONTAINER_DLL_insert (monitor_head, monitor_tail, r);
840 GNUNET_SERVER_receive_done (client, GNUNET_OK);
844 * Handler for monitor stop messages
846 * @param cls closure for the service
847 * @param client the client we received this message from
848 * @param message the actual message received
852 handle_dht_local_monitor_stop (void *cls, struct GNUNET_SERVER_Client *client,
853 const struct GNUNET_MessageHeader *message)
855 struct ClientMonitorRecord *r;
856 const struct GNUNET_DHT_MonitorStartStopMessage *msg;
859 msg = (struct GNUNET_DHT_MonitorStartStopMessage *) message;
865 keys_match = (0 == ntohs(msg->filter_key));
868 keys_match = (0 != ntohs(msg->filter_key)
869 && !memcmp(r->key, &msg->key, sizeof(struct GNUNET_HashCode)));
871 if (find_active_client(client) == r->client
872 && ntohl(msg->type) == r->type
873 && r->get == msg->get
874 && r->get_resp == msg->get_resp
875 && r->put == msg->put
879 GNUNET_CONTAINER_DLL_remove (monitor_head, monitor_tail, r);
880 GNUNET_free_non_null (r->key);
882 GNUNET_SERVER_receive_done (client, GNUNET_OK);
883 return; /* Delete only ONE entry */
888 GNUNET_SERVER_receive_done (client, GNUNET_OK);
893 * Callback called as a result of issuing a GNUNET_SERVER_notify_transmit_ready
894 * request. A ClientList is passed as closure, take the head of the list
895 * and copy it into buf, which has the result of sending the message to the
898 * @param cls closure to this call
899 * @param size maximum number of bytes available to send
900 * @param buf where to copy the actual message to
902 * @return the number of bytes actually copied, 0 indicates failure
905 send_reply_to_client (void *cls, size_t size, void *buf)
907 struct ClientList *client = cls;
909 struct PendingMessage *reply;
913 client->transmit_handle = NULL;
916 /* client disconnected */
917 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
918 "Client %p disconnected, pending messages will be discarded\n",
919 client->client_handle);
923 while ((NULL != (reply = client->pending_head)) &&
924 (size >= off + (msize = ntohs (reply->msg->size))))
926 GNUNET_CONTAINER_DLL_remove (client->pending_head, client->pending_tail,
928 memcpy (&cbuf[off], reply->msg, msize);
930 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitting %u bytes to client %p\n",
931 msize, client->client_handle);
934 process_pending_messages (client);
935 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transmitted %u/%u bytes to client %p\n",
936 (unsigned int) off, (unsigned int) size, client->client_handle);
942 * Task run to check for messages that need to be sent to a client.
944 * @param client a ClientList, containing the client and any messages to be sent to it
947 process_pending_messages (struct ClientList *client)
949 if ((client->pending_head == NULL) || (client->transmit_handle != NULL))
951 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
952 "Not asking for transmission to %p now: %s\n",
953 client->client_handle,
954 client->pending_head ==
955 NULL ? "no more messages" : "request already pending");
958 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
959 "Asking for transmission of %u bytes to client %p\n",
960 ntohs (client->pending_head->msg->size), client->client_handle);
961 client->transmit_handle =
962 GNUNET_SERVER_notify_transmit_ready (client->client_handle,
963 ntohs (client->pending_head->
965 GNUNET_TIME_UNIT_FOREVER_REL,
966 &send_reply_to_client, client);
971 * Closure for 'forward_reply'
973 struct ForwardReplyContext
977 * Actual message to send to matching clients.
979 struct PendingMessage *pm;
989 enum GNUNET_BLOCK_Type type;
992 * Number of bytes in data.
997 * Do we need to copy 'pm' because it was already used?
1005 * Iterator over hash map entries that send a given reply to
1006 * each of the matching clients. With some tricky recycling
1009 * @param cls the 'struct ForwardReplyContext'
1010 * @param key current key
1011 * @param value value in the hash map, a ClientQueryRecord
1012 * @return GNUNET_YES (we should continue to iterate),
1013 * if the result is mal-formed, GNUNET_NO
1016 forward_reply (void *cls, const struct GNUNET_HashCode * key, void *value)
1018 struct ForwardReplyContext *frc = cls;
1019 struct ClientQueryRecord *record = value;
1020 struct PendingMessage *pm;
1021 struct GNUNET_DHT_ClientResultMessage *reply;
1022 enum GNUNET_BLOCK_EvaluationResult eval;
1024 struct GNUNET_HashCode ch;
1027 if (LOG_ROUTE_DETAILS_STDERR)
1029 LOG (GNUNET_ERROR_TYPE_DEBUG,
1030 "XDHT CLIENT-RESULT %s @ %u\n",
1034 if ((record->type != GNUNET_BLOCK_TYPE_ANY) && (record->type != frc->type))
1036 LOG (GNUNET_ERROR_TYPE_DEBUG,
1037 "Record type missmatch, not passing request for key %s to local client\n",
1039 GNUNET_STATISTICS_update (GDS_stats,
1041 ("# Key match, type mismatches in REPLY to CLIENT"),
1043 return GNUNET_YES; /* type mismatch */
1045 GNUNET_CRYPTO_hash (frc->data, frc->data_size, &ch);
1046 for (i = 0; i < record->seen_replies_count; i++)
1047 if (0 == memcmp (&record->seen_replies[i], &ch, sizeof (struct GNUNET_HashCode)))
1049 LOG (GNUNET_ERROR_TYPE_DEBUG,
1050 "Duplicate reply, not passing request for key %s to local client\n",
1052 GNUNET_STATISTICS_update (GDS_stats,
1054 ("# Duplicate REPLIES to CLIENT request dropped"),
1056 return GNUNET_YES; /* duplicate */
1059 GNUNET_BLOCK_evaluate (GDS_block_context, record->type, key, NULL, 0,
1060 record->xquery, record->xquery_size, frc->data,
1062 LOG (GNUNET_ERROR_TYPE_DEBUG,
1063 "Evaluation result is %d for key %s for local client's query\n",
1064 (int) eval, GNUNET_h2s (key));
1067 case GNUNET_BLOCK_EVALUATION_OK_LAST:
1068 do_free = GNUNET_YES;
1070 case GNUNET_BLOCK_EVALUATION_OK_MORE:
1071 GNUNET_array_append (record->seen_replies, record->seen_replies_count, ch);
1072 do_free = GNUNET_NO;
1074 case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
1075 /* should be impossible to encounter here */
1078 case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
1079 GNUNET_break_op (0);
1081 case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
1084 case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
1087 case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
1089 case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
1090 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1091 _("Unsupported block type (%u) in request!\n"), record->type);
1097 if (GNUNET_NO == frc->do_copy)
1099 /* first time, we can use the original data */
1101 frc->do_copy = GNUNET_YES;
1105 /* two clients waiting for same reply, must copy for queueing */
1106 pm = GNUNET_malloc (sizeof (struct PendingMessage) +
1107 ntohs (frc->pm->msg->size));
1108 memcpy (pm, frc->pm,
1109 sizeof (struct PendingMessage) + ntohs (frc->pm->msg->size));
1110 pm->next = pm->prev = NULL;
1111 pm->msg = (struct GNUNET_MessageHeader *) &pm[1];
1113 GNUNET_STATISTICS_update (GDS_stats,
1114 gettext_noop ("# RESULTS queued for clients"), 1,
1116 reply = (struct GNUNET_DHT_ClientResultMessage *) &pm[1];
1117 reply->unique_id = record->unique_id;
1118 LOG (GNUNET_ERROR_TYPE_DEBUG,
1119 "Queueing reply to query %s for client %p\n", GNUNET_h2s (key),
1120 record->client->client_handle);
1121 add_pending_message (record->client, pm);
1122 if (GNUNET_YES == do_free)
1123 remove_client_records (record->client, key, record);
1129 * Handle a reply we've received from another peer. If the reply
1130 * matches any of our pending queries, forward it to the respective
1133 * @param expiration when will the reply expire
1134 * @param key the query this reply is for
1135 * @param get_path_length number of peers in 'get_path'
1136 * @param get_path path the reply took on get
1137 * @param put_path_length number of peers in 'put_path'
1138 * @param put_path path the reply took on put
1139 * @param type type of the reply
1140 * @param data_size number of bytes in 'data'
1141 * @param data application payload data
1144 GDS_CLIENTS_handle_reply (struct GNUNET_TIME_Absolute expiration,
1145 const struct GNUNET_HashCode *key,
1146 unsigned int get_path_length,
1147 const struct GNUNET_PeerIdentity *get_path,
1148 unsigned int put_path_length,
1149 const struct GNUNET_PeerIdentity *put_path,
1150 enum GNUNET_BLOCK_Type type, size_t data_size,
1153 struct ForwardReplyContext frc;
1154 struct PendingMessage *pm;
1155 struct GNUNET_DHT_ClientResultMessage *reply;
1156 struct GNUNET_PeerIdentity *paths;
1159 LOG (GNUNET_ERROR_TYPE_DEBUG, "reply for key %s\n", GNUNET_h2s (key));
1161 if (NULL == GNUNET_CONTAINER_multihashmap_get (forward_map, key))
1163 GNUNET_STATISTICS_update (GDS_stats,
1165 ("# REPLIES ignored for CLIENTS (no match)"), 1,
1167 return; /* no matching request, fast exit! */
1170 sizeof (struct GNUNET_DHT_ClientResultMessage) + data_size +
1171 (get_path_length + put_path_length) * sizeof (struct GNUNET_PeerIdentity);
1172 if (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1174 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1175 _("Could not pass reply to client, message too big!\n"));
1178 pm = GNUNET_malloc (msize + sizeof (struct PendingMessage));
1179 reply = (struct GNUNET_DHT_ClientResultMessage *) &pm[1];
1180 pm->msg = &reply->header;
1181 reply->header.size = htons ((uint16_t) msize);
1182 reply->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CLIENT_RESULT);
1183 reply->type = htonl (type);
1184 reply->get_path_length = htonl (get_path_length);
1185 reply->put_path_length = htonl (put_path_length);
1186 reply->unique_id = 0; /* filled in later */
1187 reply->expiration = GNUNET_TIME_absolute_hton (expiration);
1189 paths = (struct GNUNET_PeerIdentity *) &reply[1];
1190 memcpy (paths, put_path,
1191 sizeof (struct GNUNET_PeerIdentity) * put_path_length);
1192 memcpy (&paths[put_path_length], get_path,
1193 sizeof (struct GNUNET_PeerIdentity) * get_path_length);
1194 memcpy (&paths[get_path_length + put_path_length], data, data_size);
1195 frc.do_copy = GNUNET_NO;
1198 frc.data_size = data_size;
1200 GNUNET_CONTAINER_multihashmap_get_multiple (forward_map, key, &forward_reply,
1202 if (GNUNET_NO == frc.do_copy)
1204 /* did not match any of the requests, free! */
1205 GNUNET_STATISTICS_update (GDS_stats,
1207 ("# REPLIES ignored for CLIENTS (no match)"), 1,
1215 * Check if some client is monitoring GET messages and notify
1216 * them in that case.
1218 * @param options Options, for instance RecordRoute, DemultiplexEverywhere.
1219 * @param type The type of data in the request.
1220 * @param hop_count Hop count so far.
1221 * @param path_length number of entries in path (or 0 if not recorded).
1222 * @param path peers on the GET path (or NULL if not recorded).
1223 * @param desired_replication_level Desired replication level.
1224 * @param key Key of the requested data.
1227 GDS_CLIENTS_process_get (uint32_t options,
1228 enum GNUNET_BLOCK_Type type,
1230 uint32_t desired_replication_level,
1231 unsigned int path_length,
1232 const struct GNUNET_PeerIdentity *path,
1233 const struct GNUNET_HashCode * key)
1235 struct ClientMonitorRecord *m;
1236 struct ClientList **cl;
1237 unsigned int cl_size;
1241 for (m = monitor_head; NULL != m; m = m->next)
1243 if ((GNUNET_BLOCK_TYPE_ANY == m->type || m->type == type) &&
1245 memcmp (key, m->key, sizeof(struct GNUNET_HashCode)) == 0))
1247 struct PendingMessage *pm;
1248 struct GNUNET_DHT_MonitorGetMessage *mmsg;
1249 struct GNUNET_PeerIdentity *msg_path;
1253 /* Don't send duplicates */
1254 for (i = 0; i < cl_size; i++)
1255 if (cl[i] == m->client)
1259 GNUNET_array_append (cl, cl_size, m->client);
1261 msize = path_length * sizeof (struct GNUNET_PeerIdentity);
1262 msize += sizeof (struct GNUNET_DHT_MonitorGetMessage);
1263 msize += sizeof (struct PendingMessage);
1264 pm = GNUNET_malloc (msize);
1265 mmsg = (struct GNUNET_DHT_MonitorGetMessage *) &pm[1];
1266 pm->msg = &mmsg->header;
1267 mmsg->header.size = htons (msize - sizeof (struct PendingMessage));
1268 mmsg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_MONITOR_GET);
1269 mmsg->options = htonl(options);
1270 mmsg->type = htonl(type);
1271 mmsg->hop_count = htonl(hop_count);
1272 mmsg->desired_replication_level = htonl(desired_replication_level);
1273 mmsg->get_path_length = htonl(path_length);
1274 memcpy (&mmsg->key, key, sizeof (struct GNUNET_HashCode));
1275 msg_path = (struct GNUNET_PeerIdentity *) &mmsg[1];
1276 if (path_length > 0)
1277 memcpy (msg_path, path,
1278 path_length * sizeof (struct GNUNET_PeerIdentity));
1279 add_pending_message (m->client, pm);
1282 GNUNET_free_non_null (cl);
1287 * Check if some client is monitoring GET RESP messages and notify
1288 * them in that case.
1290 * @param type The type of data in the result.
1291 * @param get_path Peers on GET path (or NULL if not recorded).
1292 * @param get_path_length number of entries in get_path.
1293 * @param put_path peers on the PUT path (or NULL if not recorded).
1294 * @param put_path_length number of entries in get_path.
1295 * @param exp Expiration time of the data.
1296 * @param key Key of the data.
1297 * @param data Pointer to the result data.
1298 * @param size Number of bytes in data.
1301 GDS_CLIENTS_process_get_resp (enum GNUNET_BLOCK_Type type,
1302 const struct GNUNET_PeerIdentity *get_path,
1303 unsigned int get_path_length,
1304 const struct GNUNET_PeerIdentity *put_path,
1305 unsigned int put_path_length,
1306 struct GNUNET_TIME_Absolute exp,
1307 const struct GNUNET_HashCode * key,
1311 struct ClientMonitorRecord *m;
1312 struct ClientList **cl;
1313 unsigned int cl_size;
1317 for (m = monitor_head; NULL != m; m = m->next)
1319 if ((GNUNET_BLOCK_TYPE_ANY == m->type || m->type == type) &&
1321 memcmp (key, m->key, sizeof(struct GNUNET_HashCode)) == 0))
1323 struct PendingMessage *pm;
1324 struct GNUNET_DHT_MonitorGetRespMessage *mmsg;
1325 struct GNUNET_PeerIdentity *path;
1329 /* Don't send duplicates */
1330 for (i = 0; i < cl_size; i++)
1331 if (cl[i] == m->client)
1335 GNUNET_array_append (cl, cl_size, m->client);
1338 msize += (get_path_length + put_path_length)
1339 * sizeof (struct GNUNET_PeerIdentity);
1340 msize += sizeof (struct GNUNET_DHT_MonitorGetRespMessage);
1341 msize += sizeof (struct PendingMessage);
1342 pm = GNUNET_malloc (msize);
1343 mmsg = (struct GNUNET_DHT_MonitorGetRespMessage *) &pm[1];
1344 pm->msg = (struct GNUNET_MessageHeader *) mmsg;
1345 mmsg->header.size = htons (msize - sizeof (struct PendingMessage));
1346 mmsg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_MONITOR_GET_RESP);
1347 mmsg->type = htonl(type);
1348 mmsg->put_path_length = htonl(put_path_length);
1349 mmsg->get_path_length = htonl(get_path_length);
1350 path = (struct GNUNET_PeerIdentity *) &mmsg[1];
1351 if (put_path_length > 0)
1353 memcpy (path, put_path,
1354 put_path_length * sizeof (struct GNUNET_PeerIdentity));
1355 path = &path[put_path_length];
1357 if (get_path_length > 0)
1358 memcpy (path, get_path,
1359 get_path_length * sizeof (struct GNUNET_PeerIdentity));
1360 mmsg->expiration_time = GNUNET_TIME_absolute_hton(exp);
1361 memcpy (&mmsg->key, key, sizeof (struct GNUNET_HashCode));
1363 memcpy (&path[get_path_length], data, size);
1364 add_pending_message (m->client, pm);
1367 GNUNET_free_non_null (cl);
1372 * Check if some client is monitoring PUT messages and notify
1373 * them in that case.
1375 * @param options Options, for instance RecordRoute, DemultiplexEverywhere.
1376 * @param type The type of data in the request.
1377 * @param hop_count Hop count so far.
1378 * @param path_length number of entries in path (or 0 if not recorded).
1379 * @param path peers on the PUT path (or NULL if not recorded).
1380 * @param desired_replication_level Desired replication level.
1381 * @param exp Expiration time of the data.
1382 * @param key Key under which data is to be stored.
1383 * @param data Pointer to the data carried.
1384 * @param size Number of bytes in data.
1387 GDS_CLIENTS_process_put (uint32_t options,
1388 enum GNUNET_BLOCK_Type type,
1390 uint32_t desired_replication_level,
1391 unsigned int path_length,
1392 const struct GNUNET_PeerIdentity *path,
1393 struct GNUNET_TIME_Absolute exp,
1394 const struct GNUNET_HashCode * key,
1398 struct ClientMonitorRecord *m;
1399 struct ClientList **cl;
1400 unsigned int cl_size;
1404 for (m = monitor_head; NULL != m; m = m->next)
1406 if ((GNUNET_BLOCK_TYPE_ANY == m->type || m->type == type) &&
1408 memcmp (key, m->key, sizeof(struct GNUNET_HashCode)) == 0))
1410 struct PendingMessage *pm;
1411 struct GNUNET_DHT_MonitorPutMessage *mmsg;
1412 struct GNUNET_PeerIdentity *msg_path;
1416 /* Don't send duplicates */
1417 for (i = 0; i < cl_size; i++)
1418 if (cl[i] == m->client)
1422 GNUNET_array_append (cl, cl_size, m->client);
1425 msize += path_length * sizeof (struct GNUNET_PeerIdentity);
1426 msize += sizeof (struct GNUNET_DHT_MonitorPutMessage);
1427 msize += sizeof (struct PendingMessage);
1428 pm = GNUNET_malloc (msize);
1429 mmsg = (struct GNUNET_DHT_MonitorPutMessage *) &pm[1];
1430 pm->msg = (struct GNUNET_MessageHeader *) mmsg;
1431 mmsg->header.size = htons (msize - sizeof (struct PendingMessage));
1432 mmsg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_MONITOR_PUT);
1433 mmsg->options = htonl(options);
1434 mmsg->type = htonl(type);
1435 mmsg->hop_count = htonl(hop_count);
1436 mmsg->desired_replication_level = htonl(desired_replication_level);
1437 mmsg->put_path_length = htonl(path_length);
1438 msg_path = (struct GNUNET_PeerIdentity *) &mmsg[1];
1439 if (path_length > 0)
1441 memcpy (msg_path, path,
1442 path_length * sizeof (struct GNUNET_PeerIdentity));
1444 mmsg->expiration_time = GNUNET_TIME_absolute_hton(exp);
1445 memcpy (&mmsg->key, key, sizeof (struct GNUNET_HashCode));
1447 memcpy (&msg_path[path_length], data, size);
1448 add_pending_message (m->client, pm);
1451 GNUNET_free_non_null (cl);
1456 * Initialize client subsystem.
1458 * @param server the initialized server
1461 GDS_CLIENTS_init (struct GNUNET_SERVER_Handle *server)
1463 static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = {
1464 {&handle_dht_local_put, NULL,
1465 GNUNET_MESSAGE_TYPE_DHT_CLIENT_PUT, 0},
1466 {&handle_dht_local_get, NULL,
1467 GNUNET_MESSAGE_TYPE_DHT_CLIENT_GET, 0},
1468 {&handle_dht_local_get_stop, NULL,
1469 GNUNET_MESSAGE_TYPE_DHT_CLIENT_GET_STOP,
1470 sizeof (struct GNUNET_DHT_ClientGetStopMessage)},
1471 {&handle_dht_local_monitor, NULL,
1472 GNUNET_MESSAGE_TYPE_DHT_MONITOR_START,
1473 sizeof (struct GNUNET_DHT_MonitorStartStopMessage)},
1474 {&handle_dht_local_monitor_stop, NULL,
1475 GNUNET_MESSAGE_TYPE_DHT_MONITOR_STOP,
1476 sizeof (struct GNUNET_DHT_MonitorStartStopMessage)},
1477 {&handle_dht_local_get_result_seen, NULL,
1478 GNUNET_MESSAGE_TYPE_DHT_CLIENT_GET_RESULTS_KNOWN, 0},
1481 forward_map = GNUNET_CONTAINER_multihashmap_create (1024, GNUNET_NO);
1482 retry_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
1483 GNUNET_SERVER_add_handlers (server, plugin_handlers);
1484 GNUNET_SERVER_disconnect_notify (server, &handle_client_disconnect, NULL);
1489 * Shutdown client subsystem.
1494 GNUNET_assert (client_head == NULL);
1495 GNUNET_assert (client_tail == NULL);
1496 if (GNUNET_SCHEDULER_NO_TASK != retry_task)
1498 GNUNET_SCHEDULER_cancel (retry_task);
1499 retry_task = GNUNET_SCHEDULER_NO_TASK;
1501 if (NULL != retry_heap)
1503 GNUNET_assert (0 == GNUNET_CONTAINER_heap_get_size (retry_heap));
1504 GNUNET_CONTAINER_heap_destroy (retry_heap);
1507 if (NULL != forward_map)
1509 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (forward_map));
1510 GNUNET_CONTAINER_multihashmap_destroy (forward_map);
1515 /* end of gnunet-service-dht_clients.c */