/* This file is part of GNUnet. (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file dht/gnunet-service-dht.c * @brief GNUnet DHT service * @author Christian Grothoff * @author Nathan Evans * * TODO: * - use OPTION_MULTIPLE instead of linked list for the forward_list.hashmap * - use different 'struct DHT_MessageContext' for the different types of * messages (currently rather confusing, especially with things like * peer bloom filters occuring when processing replies). */ #include "platform.h" #include "gnunet_block_lib.h" #include "gnunet_client_lib.h" #include "gnunet_getopt_lib.h" #include "gnunet_os_lib.h" #include "gnunet_protocols.h" #include "gnunet_service_lib.h" #include "gnunet_nse_service.h" #include "gnunet_core_service.h" #include "gnunet_signal_lib.h" #include "gnunet_util_lib.h" #include "gnunet_datacache_lib.h" #include "gnunet_transport_service.h" #include "gnunet_hello_lib.h" #include "gnunet_dht_service.h" #include "gnunet_statistics_service.h" #include "dht.h" #include /** * Defines whether find peer requests send their HELLO's outgoing, * or expect replies to contain hellos. */ #define FIND_PEER_WITH_HELLO GNUNET_YES #define DEFAULT_CORE_QUEUE_SIZE 32 /** * Minimum number of peers we need for "good" routing, * any less than this and we will allow messages to * travel much further through the network! */ #define MINIMUM_PEER_THRESHOLD 20 /** * Number of requests we track at most (for routing replies). */ #define DHT_MAX_RECENT (1024 * 16) /** * How long do we wait at most when queueing messages with core * that we are sending on behalf of other peers. */ #define DHT_DEFAULT_P2P_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10) /** * Default importance for handling messages on behalf of other peers. */ #define DHT_DEFAULT_P2P_IMPORTANCE 0 /** * How long to keep recent requests around by default. */ #define DEFAULT_RECENT_REMOVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60) /** * Default time to wait to send find peer messages sent by the dht service. */ #define DHT_DEFAULT_FIND_PEER_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30) /** * Default importance for find peer messages sent by the dht service. */ #define DHT_DEFAULT_FIND_PEER_IMPORTANCE 8 /** * Default replication parameter for find peer messages sent by the dht service. */ #define DHT_DEFAULT_FIND_PEER_REPLICATION 4 /** * How long at least to wait before sending another find peer request. */ #define DHT_MINIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2) /** * How long at most to wait before sending another find peer request. */ #define DHT_MAXIMUM_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 8) /** * How often to update our preference levels for peers in our routing tables. */ #define DHT_DEFAULT_PREFERENCE_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 2) /** * How long at most on average will we allow a reply forward to take * (before we quit sending out new requests) */ #define MAX_REQUEST_TIME GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1) /** * How many time differences between requesting a core send and * the actual callback to remember. */ #define MAX_REPLY_TIMES 8 /** * Context containing information about a DHT message received. */ struct DHT_MessageContext { /** * The client this request was received from. * (NULL if received from another peer) */ struct ClientList *client; /** * The peer this request was received from. */ struct GNUNET_PeerIdentity peer; /** * Bloomfilter for this routing request. */ struct GNUNET_CONTAINER_BloomFilter *bloom; /** * extended query (see gnunet_block_lib.h). */ const void *xquery; /** * Bloomfilter to filter out duplicate replies. */ struct GNUNET_CONTAINER_BloomFilter *reply_bf; /** * The key this request was about */ GNUNET_HashCode key; /** * How long should we wait to transmit this request? */ struct GNUNET_TIME_Relative timeout; /** * The unique identifier of this request */ uint64_t unique_id; /** * Number of bytes in xquery. */ size_t xquery_size; /** * Mutator value for the reply_bf, see gnunet_block_lib.h */ uint32_t reply_bf_mutator; /** * Desired replication level */ uint32_t replication; /** * Network size estimate, either ours or the sum of * those routed to thus far. =~ Log of number of peers * chosen from for this request. */ uint32_t network_size; /** * Any message options for this request */ uint32_t msg_options; /** * How many hops has the message already traversed? */ uint32_t hop_count; /** * How many peer identities are present in the path history? */ uint32_t path_history_len; /** * Path history. */ char *path_history; /** * How important is this message? */ unsigned int importance; /** * Should we (still) forward the request on to other peers? */ int do_forward; /** * Did we forward this message? (may need to remember it!) */ int forwarded; /** * Are we the closest known peer to this key (out of our neighbors?) */ int closest; }; /** * Record used for remembering what peers are waiting for what * responses (based on search key). */ struct DHTRouteSource { /** * This is a DLL. */ struct DHTRouteSource *next; /** * This is a DLL. */ struct DHTRouteSource *prev; /** * UID of the request, 0 if from another peer. */ uint64_t uid; /** * Source of the request. Replies should be forwarded to * this peer. */ struct GNUNET_PeerIdentity source; /** * If this was a local request, remember the client; otherwise NULL. */ struct ClientList *client; /** * Pointer to this nodes heap location (for removal) */ struct GNUNET_CONTAINER_HeapNode *hnode; /** * Back pointer to the record storing this information. */ struct DHTQueryRecord *record; /** * Task to remove this entry on timeout. */ GNUNET_SCHEDULER_TaskIdentifier delete_task; /** * Bloomfilter of peers we have already sent back as * replies to the initial request. Allows us to not * forward the same peer multiple times for a find peer * request. */ struct GNUNET_CONTAINER_BloomFilter *find_peers_responded; }; /** * Entry in the DHT routing table. */ struct DHTQueryRecord { /** * Head of DLL for result forwarding. */ struct DHTRouteSource *head; /** * Tail of DLL for result forwarding. */ struct DHTRouteSource *tail; /** * Key that the record concerns. */ GNUNET_HashCode key; }; /** * Context used to calculate the number of find peer messages * per X time units since our last scheduled find peer message * was sent. If we have seen too many messages, delay or don't * send our own out. */ struct FindPeerMessageContext { unsigned int count; struct GNUNET_TIME_Absolute start; }; struct RecentRequest { /** * Position of this node in the min heap. */ struct GNUNET_CONTAINER_HeapNode *heap_node; /** * Bloomfilter containing entries for peers * we forwarded this request to. */ struct GNUNET_CONTAINER_BloomFilter *bloom; /** * Timestamp of this request, for ordering * the min heap. */ struct GNUNET_TIME_Absolute timestamp; /** * Key of this request. */ GNUNET_HashCode key; /** * Unique identifier for this request, 0 if from another peer. */ uint64_t uid; /** * Task to remove this entry on timeout. */ GNUNET_SCHEDULER_TaskIdentifier remove_task; }; /** * Recent requests by time inserted. */ static struct GNUNET_CONTAINER_Heap *recent_heap; /** * Context to use to calculate find peer rates. */ static struct FindPeerMessageContext find_peer_context; /** * How many peers have we added since we sent out our last * find peer request? */ static unsigned int newly_found_peers; /** * Handle to the datacache service (for inserting/retrieving data) */ static struct GNUNET_DATACACHE_Handle *datacache; /** * Handle for the statistics service. */ struct GNUNET_STATISTICS_Handle *stats; /** * Handle to get our current HELLO. */ static struct GNUNET_TRANSPORT_GetHelloHandle *ghh; /** * The configuration the DHT service is running with */ static const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Handle to the core service */ static struct GNUNET_CORE_Handle *coreAPI; /** * Handle to the transport service, for getting our hello */ static struct GNUNET_TRANSPORT_Handle *transport_handle; /** * The identity of our peer. */ static struct GNUNET_PeerIdentity my_identity; /** * Short id of the peer, for printing */ static char *my_short_id; /** * Our HELLO */ static struct GNUNET_MessageHeader *my_hello; /** * Task to run when we shut down, cleaning up all our trash */ static GNUNET_SCHEDULER_TaskIdentifier cleanup_task; /** * Recently seen find peer requests. */ static struct GNUNET_CONTAINER_MultiHashMap *recent_find_peer_requests; /** * Reply times for requests, if we are busy, don't send any * more requests! */ static struct GNUNET_TIME_Relative reply_times[MAX_REPLY_TIMES]; /** * Current counter for replies. */ static unsigned int reply_counter; /** * Our handle to the BLOCK library. */ static struct GNUNET_BLOCK_Context *block_context; /** Declare here so retry_core_send is aware of it */ static size_t core_transmit_notify (void *cls, size_t size, void *buf); /** * Given the largest send delay, artificially decrease it * so the next time around we may have a chance at sending * again. */ static void decrease_max_send_delay (struct GNUNET_TIME_Relative max_time) { unsigned int i; for (i = 0; i < MAX_REPLY_TIMES; i++) { if (reply_times[i].rel_value == max_time.rel_value) { reply_times[i].rel_value = reply_times[i].rel_value / 2; return; } } } /** * Find the maximum send time of the recently sent values. * * @return the average time between asking core to send a message * and when the buffer for copying it is passed */ static struct GNUNET_TIME_Relative get_max_send_delay () { unsigned int i; struct GNUNET_TIME_Relative max_time; max_time = GNUNET_TIME_relative_get_zero (); for (i = 0; i < MAX_REPLY_TIMES; i++) { if (reply_times[i].rel_value > max_time.rel_value) max_time.rel_value = reply_times[i].rel_value; } #if DEBUG_DHT if (max_time.rel_value > MAX_REQUEST_TIME.rel_value) GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Max send delay was %llu\n", (unsigned long long) max_time.rel_value); #endif return max_time; } static void increment_stats (const char *value) { if (stats == NULL) return; GNUNET_STATISTICS_update (stats, value, 1, GNUNET_NO); } static void decrement_stats (const char *value) { if (stats == NULL) return; GNUNET_STATISTICS_update (stats, value, -1, GNUNET_NO); } /** * Try to send another message from our core send list */ static void try_core_send (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct PeerInfo *peer = cls; struct P2PPendingMessage *pending; size_t ssize; peer->send_task = GNUNET_SCHEDULER_NO_TASK; if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; if (peer->th != NULL) return; /* Message send already in progress */ pending = peer->head; if (pending != NULL) { ssize = ntohs (pending->msg->size); #if DEBUG_DHT > 1 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Calling notify_transmit_ready with size %d for peer %s\n", my_short_id, "DHT", ssize, GNUNET_i2s (&peer->id)); #endif pending->scheduled = GNUNET_TIME_absolute_get (); reply_counter++; if (reply_counter >= MAX_REPLY_TIMES) reply_counter = 0; peer->th = GNUNET_CORE_notify_transmit_ready (coreAPI, GNUNET_YES, pending->importance, pending->timeout, &peer->id, ssize, &core_transmit_notify, peer); if (peer->th == NULL) increment_stats ("# notify transmit ready failed"); } } /** * Function called to send a request out to another peer. * Called both for locally initiated requests and those * received from other peers. * * @param msg the encapsulated message * @param peer the peer to forward the message to * @param msg_ctx the context of the message (hop count, bloom, etc.) */ static void forward_result_message (const struct GNUNET_MessageHeader *msg, struct PeerInfo *peer, struct DHT_MessageContext *msg_ctx) { struct GNUNET_DHT_P2PRouteResultMessage *result_message; struct P2PPendingMessage *pending; size_t msize; size_t psize; char *path_start; char *path_offset; increment_stats (STAT_RESULT_FORWARDS); msize = sizeof (struct GNUNET_DHT_P2PRouteResultMessage) + ntohs (msg->size) + (sizeof (struct GNUNET_PeerIdentity) * msg_ctx->path_history_len); GNUNET_assert (msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE); psize = sizeof (struct P2PPendingMessage) + msize; pending = GNUNET_malloc (psize); pending->msg = (struct GNUNET_MessageHeader *) &pending[1]; pending->importance = DHT_SEND_PRIORITY; pending->timeout = GNUNET_TIME_relative_get_forever (); result_message = (struct GNUNET_DHT_P2PRouteResultMessage *) pending->msg; result_message->header.size = htons (msize); result_message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE_RESULT); result_message->outgoing_path_length = htonl (msg_ctx->path_history_len); if (msg_ctx->path_history_len > 0) { /* End of pending is where enc_msg starts */ path_start = (char *) &pending[1]; /* Offset by the size of the enc_msg */ path_start += ntohs (msg->size); memcpy (path_start, msg_ctx->path_history, msg_ctx->path_history_len * (sizeof (struct GNUNET_PeerIdentity))); } result_message->options = htonl (msg_ctx->msg_options); result_message->hop_count = htonl (msg_ctx->hop_count + 1); memcpy (&result_message->key, &msg_ctx->key, sizeof (GNUNET_HashCode)); /* Copy the enc_msg, then the path history as well! */ memcpy (&result_message[1], msg, ntohs (msg->size)); path_offset = (char *) &result_message[1]; path_offset += ntohs (msg->size); /* If we have path history, copy it to the end of the whole thing */ if (msg_ctx->path_history_len > 0) memcpy (path_offset, msg_ctx->path_history, msg_ctx->path_history_len * (sizeof (struct GNUNET_PeerIdentity))); #if DEBUG_DHT > 1 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Adding pending message size %d for peer %s\n", my_short_id, "DHT", msize, GNUNET_i2s (&peer->id)); #endif peer->pending_count++; increment_stats ("# pending messages scheduled"); GNUNET_CONTAINER_DLL_insert_after (peer->head, peer->tail, peer->tail, pending); if (peer->send_task == GNUNET_SCHEDULER_NO_TASK) peer->send_task = GNUNET_SCHEDULER_add_now (&try_core_send, peer); } /** * Called when core is ready to send a message we asked for * out to the destination. * * @param cls closure (NULL) * @param size number of bytes available in buf * @param buf where the callee should write the message * @return number of bytes written to buf */ static size_t core_transmit_notify (void *cls, size_t size, void *buf) { struct PeerInfo *peer = cls; char *cbuf = buf; struct P2PPendingMessage *pending; size_t off; size_t msize; peer->th = NULL; if (buf == NULL) { /* client disconnected */ #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': buffer was NULL\n", my_short_id, "DHT"); #endif return 0; } if (peer->head == NULL) return 0; off = 0; pending = peer->head; while (NULL != pending && (size - off >= (msize = ntohs (pending->msg->size)))) { memcpy (&cbuf[off], pending->msg, msize); off += msize; peer->pending_count--; increment_stats ("# pending messages sent"); GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending); GNUNET_free (pending); pending = peer->head; } if ((peer->head != NULL) && (peer->send_task == GNUNET_SCHEDULER_NO_TASK)) peer->send_task = GNUNET_SCHEDULER_add_now (&try_core_send, peer); return off; } /** * Compute the distance between have and target as a 32-bit value. * Differences in the lower bits must count stronger than differences * in the higher bits. * * @return 0 if have==target, otherwise a number * that is larger as the distance between * the two hash codes increases */ static unsigned int distance (const GNUNET_HashCode * target, const GNUNET_HashCode * have) { unsigned int bucket; unsigned int msb; unsigned int lsb; unsigned int i; /* We have to represent the distance between two 2^9 (=512)-bit * numbers as a 2^5 (=32)-bit number with "0" being used for the * two numbers being identical; furthermore, we need to * guarantee that a difference in the number of matching * bits is always represented in the result. * * We use 2^32/2^9 numerical values to distinguish between * hash codes that have the same LSB bit distance and * use the highest 2^9 bits of the result to signify the * number of (mis)matching LSB bits; if we have 0 matching * and hence 512 mismatching LSB bits we return -1 (since * 512 itself cannot be represented with 9 bits) */ /* first, calculate the most significant 9 bits of our * result, aka the number of LSBs */ bucket = GNUNET_CRYPTO_hash_matching_bits (target, have); /* bucket is now a value between 0 and 512 */ if (bucket == 512) return 0; /* perfect match */ if (bucket == 0) return (unsigned int) -1; /* LSB differs; use max (if we did the bit-shifting * below, we'd end up with max+1 (overflow)) */ /* calculate the most significant bits of the final result */ msb = (512 - bucket) << (32 - 9); /* calculate the 32-9 least significant bits of the final result by * looking at the differences in the 32-9 bits following the * mismatching bit at 'bucket' */ lsb = 0; for (i = bucket + 1; (i < sizeof (GNUNET_HashCode) * 8) && (i < bucket + 1 + 32 - 9); i++) { if (GNUNET_CRYPTO_hash_get_bit (target, i) != GNUNET_CRYPTO_hash_get_bit (have, i)) lsb |= (1 << (bucket + 32 - 9 - i)); /* first bit set will be 10, * last bit set will be 31 -- if * i does not reach 512 first... */ } return msb | lsb; } /** * Return a number that is larger the closer the * "have" GNUNET_hash code is to the "target". * * @return inverse distance metric, non-zero. * Must fudge the value if NO bits match. */ static unsigned int inverse_distance (const GNUNET_HashCode * target, const GNUNET_HashCode * have) { if (GNUNET_CRYPTO_hash_matching_bits (target, have) == 0) return 1; /* Never return 0! */ return ((unsigned int) -1) - distance (target, have); } /** * Find which k-bucket this peer should go into, * taking into account the size of the k-bucket * array. This means that if more bits match than * there are currently buckets, lowest_bucket will * be returned. * * @param hc GNUNET_HashCode we are finding the bucket for. * * @return the proper bucket index for this key, * or GNUNET_SYSERR on error (same hashcode) */ static int find_current_bucket (const GNUNET_HashCode * hc) { int actual_bucket; actual_bucket = find_bucket (hc); if (actual_bucket == GNUNET_SYSERR) /* hc and our peer identity match! */ return lowest_bucket; if (actual_bucket < lowest_bucket) /* actual_bucket not yet used */ return lowest_bucket; return actual_bucket; } /** * Find a routing table entry from a peer identity * * @param peer the peer identity to look up * * @return the routing table entry, or NULL if not found */ static struct PeerInfo * find_peer_by_id (const struct GNUNET_PeerIdentity *peer) { int bucket; struct PeerInfo *pos; bucket = find_current_bucket (&peer->hashPubKey); if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity))) return NULL; pos = k_buckets[bucket].head; while (pos != NULL) { if (0 == memcmp (&pos->id, peer, sizeof (struct GNUNET_PeerIdentity))) return pos; pos = pos->next; } return NULL; /* No such peer. */ } /* Forward declaration */ static void update_core_preference (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); /** * Function called with statistics about the given peer. * * @param cls closure * @param peer identifies the peer * @param bpm_out set to the current bandwidth limit (sending) for this peer * @param amount set to the amount that was actually reserved or unreserved; * either the full requested amount or zero (no partial reservations) * @param res_delay if the reservation could not be satisfied (amount was 0), how * long should the client wait until re-trying? * @param preference current traffic preference for the given peer */ static void update_core_preference_finish (void *cls, const struct GNUNET_PeerIdentity *peer, struct GNUNET_BANDWIDTH_Value32NBO bpm_out, int32_t amount, struct GNUNET_TIME_Relative res_delay, uint64_t preference) { struct PeerInfo *peer_info = cls; peer_info->info_ctx = NULL; GNUNET_SCHEDULER_add_delayed (DHT_DEFAULT_PREFERENCE_INTERVAL, &update_core_preference, peer_info); } static void update_core_preference (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct PeerInfo *peer = cls; uint64_t preference; unsigned int matching; if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) { return; } matching = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, &peer->id.hashPubKey); if (matching >= 64) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Peer identifier matches by %u bits, only shifting as much as we can!\n", matching); #endif matching = 63; } preference = 1LL << matching; peer->info_ctx = GNUNET_CORE_peer_change_preference (coreAPI, &peer->id, GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_BANDWIDTH_VALUE_MAX, 0, preference, &update_core_preference_finish, peer); } /** * Find the closest peer in our routing table to the * given hashcode. * * @return The closest peer in our routing table to the * key, or NULL on error. */ static struct PeerInfo * find_closest_peer (const GNUNET_HashCode * hc) { struct PeerInfo *pos; struct PeerInfo *current_closest; unsigned int lowest_distance; unsigned int temp_distance; int bucket; int count; lowest_distance = -1; if (k_buckets[lowest_bucket].peers_size == 0) return NULL; current_closest = NULL; for (bucket = lowest_bucket; bucket < MAX_BUCKETS; bucket++) { pos = k_buckets[bucket].head; count = 0; while ((pos != NULL) && (count < bucket_size)) { temp_distance = distance (&pos->id.hashPubKey, hc); if (temp_distance <= lowest_distance) { lowest_distance = temp_distance; current_closest = pos; } pos = pos->next; count++; } } GNUNET_assert (current_closest != NULL); return current_closest; } /** * Function called to send a request out to another peer. * Called both for locally initiated requests and those * received from other peers. * * @param msg the encapsulated message * @param peer the peer to forward the message to * @param msg_ctx the context of the message (hop count, bloom, etc.) */ static void forward_message (const struct GNUNET_MessageHeader *msg, struct PeerInfo *peer, struct DHT_MessageContext *msg_ctx) { struct GNUNET_DHT_P2PRouteMessage *route_message; struct P2PPendingMessage *pending; size_t msize; size_t psize; char *route_path; increment_stats (STAT_ROUTE_FORWARDS); GNUNET_assert (peer != NULL); if ((msg_ctx->closest != GNUNET_YES) && (peer == find_closest_peer (&msg_ctx->key))) increment_stats (STAT_ROUTE_FORWARDS_CLOSEST); msize = sizeof (struct GNUNET_DHT_P2PRouteMessage) + ntohs (msg->size) + (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); GNUNET_assert (msize <= GNUNET_SERVER_MAX_MESSAGE_SIZE); psize = sizeof (struct P2PPendingMessage) + msize; pending = GNUNET_malloc (psize); pending->msg = (struct GNUNET_MessageHeader *) &pending[1]; pending->importance = msg_ctx->importance; pending->timeout = msg_ctx->timeout; route_message = (struct GNUNET_DHT_P2PRouteMessage *) pending->msg; route_message->header.size = htons (msize); route_message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE); route_message->options = htonl (msg_ctx->msg_options); route_message->hop_count = htonl (msg_ctx->hop_count + 1); route_message->network_size = htonl (msg_ctx->network_size); route_message->desired_replication_level = htonl (msg_ctx->replication); if (msg_ctx->bloom != NULL) GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_bloomfilter_get_raw_data (msg_ctx->bloom, route_message-> bloomfilter, DHT_BLOOM_SIZE)); memcpy (&route_message->key, &msg_ctx->key, sizeof (GNUNET_HashCode)); memcpy (&route_message[1], msg, ntohs (msg->size)); if (GNUNET_DHT_RO_RECORD_ROUTE == (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE)) { route_message->outgoing_path_length = htonl (msg_ctx->path_history_len); /* Set pointer to start of enc_msg */ route_path = (char *) &route_message[1]; /* Offset to the end of the enc_msg */ route_path += ntohs (msg->size); /* Copy the route_path after enc_msg */ memcpy (route_path, msg_ctx->path_history, msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); } #if DEBUG_DHT > 1 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Adding pending message size %d for peer %s\n", my_short_id, "DHT", msize, GNUNET_i2s (&peer->id)); #endif peer->pending_count++; increment_stats ("# pending messages scheduled"); GNUNET_CONTAINER_DLL_insert_after (peer->head, peer->tail, peer->tail, pending); if (peer->send_task == GNUNET_SCHEDULER_NO_TASK) peer->send_task = GNUNET_SCHEDULER_add_now (&try_core_send, peer); } /** * Called when a reply needs to be sent to a client, as * a result it found to a GET or FIND PEER request. * * @param client the client to send the reply to * @param message the encapsulated message to send * @param msg_ctx the context of the received message */ static void send_reply_to_client (struct ClientList *client, const struct GNUNET_MessageHeader *message, struct DHT_MessageContext *msg_ctx) { struct GNUNET_DHT_RouteResultMessage *reply; struct PendingMessage *pending_message; uint16_t msize; size_t tsize; char *reply_offset; #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Sending reply to client.\n", my_short_id, "DHT"); #endif msize = ntohs (message->size); tsize = sizeof (struct GNUNET_DHT_RouteResultMessage) + msize + (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); if (tsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break_op (0); return; } pending_message = GNUNET_malloc (sizeof (struct PendingMessage) + tsize); pending_message->msg = (struct GNUNET_MessageHeader *) &pending_message[1]; reply = (struct GNUNET_DHT_RouteResultMessage *) &pending_message[1]; reply->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_RESULT); reply->header.size = htons (tsize); reply->outgoing_path_length = htonl (msg_ctx->path_history_len); reply->unique_id = GNUNET_htonll (msg_ctx->unique_id); memcpy (&reply->key, &msg_ctx->key, sizeof (GNUNET_HashCode)); reply_offset = (char *) &reply[1]; memcpy (&reply[1], message, msize); if (msg_ctx->path_history_len > 0) { reply_offset += msize; memcpy (reply_offset, msg_ctx->path_history, msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); } add_pending_message (client, pending_message); } /** * Consider whether or not we would like to have this peer added to * our routing table. Check whether bucket for this peer is full, * if so return negative; if not return positive. Since peers are * only added on CORE level connect, this doesn't actually add the * peer to the routing table. * * @param peer the peer we are considering adding * * @return GNUNET_YES if we want this peer, GNUNET_NO if not (bucket * already full) */ static int consider_peer (struct GNUNET_PeerIdentity *peer) { int bucket; if ((GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (all_known_peers, &peer->hashPubKey)) || (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity)))) return GNUNET_NO; /* We already know this peer (are connected even!) */ bucket = find_current_bucket (&peer->hashPubKey); if ((k_buckets[bucket].peers_size < bucket_size) || ((bucket == lowest_bucket) && (lowest_bucket > 0))) return GNUNET_YES; return GNUNET_NO; } /** * Task used to remove forwarding entries, either * after timeout, when full, or on shutdown. * * @param cls the entry to remove * @param tc context, reason, etc. */ static void remove_forward_entry (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct DHTRouteSource *source_info = cls; struct DHTQueryRecord *record; source_info = GNUNET_CONTAINER_heap_remove_node (source_info->hnode); record = source_info->record; GNUNET_CONTAINER_DLL_remove (record->head, record->tail, source_info); if (record->head == NULL) /* No more entries in DLL */ { GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (forward_list.hashmap, &record->key, record)); GNUNET_free (record); } if (source_info->find_peers_responded != NULL) GNUNET_CONTAINER_bloomfilter_free (source_info->find_peers_responded); GNUNET_free (source_info); } /** * Main function that handles whether or not to route a result * message to other peers, or to send to our local client. * * @param msg the result message to be routed * @param msg_ctx context of the message we are routing * * @return the number of peers the message was routed to, * GNUNET_SYSERR on failure */ static int route_result_message (struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *msg_ctx) { struct GNUNET_PeerIdentity new_peer; struct DHTQueryRecord *record; struct DHTRouteSource *pos; struct PeerInfo *peer_info; const struct GNUNET_MessageHeader *hello_msg; #if DEBUG_DHT > 1 unsigned int i; #endif increment_stats (STAT_RESULTS); /** * If a find peer result message is received and contains a valid * HELLO for another peer, offer it to the transport service. */ if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT) { if (ntohs (msg->size) <= sizeof (struct GNUNET_MessageHeader)) GNUNET_break_op (0); hello_msg = &msg[1]; if ((ntohs (hello_msg->type) != GNUNET_MESSAGE_TYPE_HELLO) || (GNUNET_SYSERR == GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) hello_msg, &new_peer))) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "%s:%s Received non-HELLO message type in find peer result message!\n", my_short_id, "DHT"); GNUNET_break_op (0); return GNUNET_NO; } else /* We have a valid hello, and peer id stored in new_peer */ { find_peer_context.count++; increment_stats (STAT_FIND_PEER_REPLY); if (GNUNET_YES == consider_peer (&new_peer)) { increment_stats (STAT_HELLOS_PROVIDED); GNUNET_TRANSPORT_offer_hello (transport_handle, hello_msg, NULL, NULL); GNUNET_CORE_peer_request_connect (coreAPI, &new_peer, NULL, NULL); } } } record = GNUNET_CONTAINER_multihashmap_get (forward_list.hashmap, &msg_ctx->key); if (record == NULL) /* No record of this message! */ { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Have no record of response key %s uid %llu\n", my_short_id, "DHT", GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id); #endif return 0; } pos = record->head; while (pos != NULL) { if (0 == memcmp (&pos->source, &my_identity, sizeof (struct GNUNET_PeerIdentity))) /* Local client (or DHT) initiated request! */ { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Sending response key %s uid %llu to client\n", my_short_id, "DHT", GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id); #endif increment_stats (STAT_RESULTS_TO_CLIENT); if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_DHT_GET_RESULT) increment_stats (STAT_GET_REPLY); #if DEBUG_DHT > 1 for (i = 0; i < msg_ctx->path_history_len; i++) { char *path_offset; path_offset = &msg_ctx->path_history[i * sizeof (struct GNUNET_PeerIdentity)]; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "(before client) Key %s Found peer %d:%s\n", GNUNET_h2s (&msg_ctx->key), i, GNUNET_i2s ((struct GNUNET_PeerIdentity *) path_offset)); } #endif send_reply_to_client (pos->client, msg, msg_ctx); } else /* Send to peer */ { peer_info = find_peer_by_id (&pos->source); if (peer_info == NULL) /* Didn't find the peer in our routing table, perhaps peer disconnected! */ { pos = pos->next; continue; } #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Forwarding response key %s uid %llu to peer %s\n", my_short_id, "DHT", GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id, GNUNET_i2s (&peer_info->id)); #endif forward_result_message (msg, peer_info, msg_ctx); /* Try removing forward entries after sending once, only allows ONE response per request */ if (pos->delete_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (pos->delete_task); pos->delete_task = GNUNET_SCHEDULER_add_now (&remove_forward_entry, pos); } } pos = pos->next; } return 0; } /** * Iterator for local get request results, * * @param cls closure for iterator, a DatacacheGetContext * @param exp when does this value expire? * @param key the key this data is stored under * @param size the size of the data identified by key * @param data the actual data * @param type the type of the data * * @return GNUNET_OK to continue iteration, anything else * to stop iteration. */ static int datacache_get_iterator (void *cls, struct GNUNET_TIME_Absolute exp, const GNUNET_HashCode * key, size_t size, const char *data, enum GNUNET_BLOCK_Type type) { struct DHT_MessageContext *msg_ctx = cls; struct DHT_MessageContext new_msg_ctx; struct GNUNET_DHT_GetResultMessage *get_result; enum GNUNET_BLOCK_EvaluationResult eval; const struct DHTPutEntry *put_entry; int get_size; char *path_offset; #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' response from datacache\n", my_short_id, "DHT", "GET"); #endif put_entry = (const struct DHTPutEntry *) data; if (size != sizeof (struct DHTPutEntry) + put_entry->data_size + (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity))) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Path + data size doesn't add up for data inserted into datacache!\nData size %d, path length %d, expected %d, got %d\n", put_entry->data_size, put_entry->path_length, sizeof (struct DHTPutEntry) + put_entry->data_size + (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity)), size); msg_ctx->do_forward = GNUNET_NO; return GNUNET_OK; } eval = GNUNET_BLOCK_evaluate (block_context, type, key, &msg_ctx->reply_bf, msg_ctx->reply_bf_mutator, msg_ctx->xquery, msg_ctx->xquery_size, &put_entry[1], put_entry->data_size); switch (eval) { case GNUNET_BLOCK_EVALUATION_OK_LAST: msg_ctx->do_forward = GNUNET_NO; case GNUNET_BLOCK_EVALUATION_OK_MORE: memcpy (&new_msg_ctx, msg_ctx, sizeof (struct DHT_MessageContext)); if (GNUNET_DHT_RO_RECORD_ROUTE == (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE)) { new_msg_ctx.msg_options = GNUNET_DHT_RO_RECORD_ROUTE; } get_size = sizeof (struct GNUNET_DHT_GetResultMessage) + put_entry->data_size + (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity)); get_result = GNUNET_malloc (get_size); get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT); get_result->header.size = htons (get_size); get_result->expiration = GNUNET_TIME_absolute_hton (exp); get_result->type = htons (type); get_result->put_path_length = htons (put_entry->path_length); path_offset = (char *) &put_entry[1]; path_offset += put_entry->data_size; /* Copy the actual data and the path_history to the end of the get result */ memcpy (&get_result[1], &put_entry[1], put_entry->data_size + (put_entry->path_length * sizeof (struct GNUNET_PeerIdentity))); new_msg_ctx.peer = my_identity; new_msg_ctx.bloom = NULL; new_msg_ctx.hop_count = 0; new_msg_ctx.importance = DHT_DEFAULT_P2P_IMPORTANCE + 2; /* Make result routing a higher priority */ new_msg_ctx.timeout = DHT_DEFAULT_P2P_TIMEOUT; increment_stats (STAT_GET_RESPONSE_START); route_result_message (&get_result->header, &new_msg_ctx); GNUNET_free (get_result); break; case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE: #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Duplicate block error\n", my_short_id, "DHT"); #endif break; case GNUNET_BLOCK_EVALUATION_RESULT_INVALID: #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "`%s:%s': Invalid request error\n", my_short_id, "DHT"); #endif break; case GNUNET_BLOCK_EVALUATION_REQUEST_VALID: #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Valid request, no results.\n", my_short_id, "DHT"); #endif GNUNET_break (0); break; case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID: GNUNET_break_op (0); msg_ctx->do_forward = GNUNET_NO; break; case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED: #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "`%s:%s': Unsupported block type (%u) in response!\n", my_short_id, "DHT", type); #endif /* msg_ctx->do_forward = GNUNET_NO; // not sure... */ break; } return GNUNET_OK; } /** * Main function that handles whether or not to route a message to other * peers. * * @param msg the message to be routed * @param msg_ctx the context containing all pertinent information about the message */ static void route_message (const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *msg_ctx); /** * Server handler for all dht get requests, look for data, * if found, send response either to clients or other peers. * * @param msg the actual get message * @param msg_ctx struct containing pertinent information about the get request * * @return number of items found for GET request */ static unsigned int handle_dht_get (const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *msg_ctx) { const struct GNUNET_DHT_GetMessage *get_msg; uint16_t msize; uint16_t bf_size; unsigned int results; const char *end; enum GNUNET_BLOCK_Type type; msize = ntohs (msg->size); if (msize < sizeof (struct GNUNET_DHT_GetMessage)) { GNUNET_break (0); return 0; } get_msg = (const struct GNUNET_DHT_GetMessage *) msg; bf_size = ntohs (get_msg->bf_size); msg_ctx->xquery_size = ntohs (get_msg->xquery_size); msg_ctx->reply_bf_mutator = get_msg->bf_mutator; if (msize != sizeof (struct GNUNET_DHT_GetMessage) + bf_size + msg_ctx->xquery_size) { GNUNET_break_op (0); return 0; } end = (const char *) &get_msg[1]; if (msg_ctx->xquery_size == 0) { msg_ctx->xquery = NULL; } else { msg_ctx->xquery = (const void *) end; end += msg_ctx->xquery_size; } if (bf_size == 0) { msg_ctx->reply_bf = NULL; } else { msg_ctx->reply_bf = GNUNET_CONTAINER_bloomfilter_init (end, bf_size, GNUNET_DHT_GET_BLOOMFILTER_K); } type = (enum GNUNET_BLOCK_Type) ntohl (get_msg->type); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request, message type %u, key %s, uid %llu\n", my_short_id, "DHT", "GET", type, GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id); #endif increment_stats (STAT_GETS); results = 0; msg_ctx->do_forward = GNUNET_YES; if (datacache != NULL) results = GNUNET_DATACACHE_get (datacache, &msg_ctx->key, type, &datacache_get_iterator, msg_ctx); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Found %d results for `%s' request uid %llu\n", my_short_id, "DHT", results, "GET", msg_ctx->unique_id); #endif if (results >= 1) { } else { /* check query valid */ if (GNUNET_BLOCK_EVALUATION_REQUEST_INVALID == GNUNET_BLOCK_evaluate (block_context, type, &msg_ctx->key, &msg_ctx->reply_bf, msg_ctx->reply_bf_mutator, msg_ctx->xquery, msg_ctx->xquery_size, NULL, 0)) { GNUNET_break_op (0); msg_ctx->do_forward = GNUNET_NO; } } if (msg_ctx->do_forward == GNUNET_YES) route_message (msg, msg_ctx); GNUNET_CONTAINER_bloomfilter_free (msg_ctx->reply_bf); return results; } static void remove_recent_find_peer (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { GNUNET_HashCode *key = cls; GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (recent_find_peer_requests, key, NULL)); GNUNET_free (key); } /** * Server handler for initiating local dht find peer requests * * @param find_msg the actual find peer message * @param msg_ctx struct containing pertinent information about the request * */ static void handle_dht_find_peer (const struct GNUNET_MessageHeader *find_msg, struct DHT_MessageContext *msg_ctx) { struct GNUNET_MessageHeader *find_peer_result; struct GNUNET_DHT_FindPeerMessage *find_peer_message; struct DHT_MessageContext *new_msg_ctx; struct GNUNET_CONTAINER_BloomFilter *incoming_bloom; size_t hello_size; size_t tsize; GNUNET_HashCode *recent_hash; struct GNUNET_MessageHeader *other_hello; size_t other_hello_size; struct GNUNET_PeerIdentity peer_id; find_peer_message = (struct GNUNET_DHT_FindPeerMessage *) find_msg; GNUNET_break_op (ntohs (find_msg->size) >= (sizeof (struct GNUNET_DHT_FindPeerMessage))); if (ntohs (find_msg->size) < sizeof (struct GNUNET_DHT_FindPeerMessage)) return; other_hello = NULL; other_hello_size = 0; if (ntohs (find_msg->size) > sizeof (struct GNUNET_DHT_FindPeerMessage)) { other_hello_size = ntohs (find_msg->size) - sizeof (struct GNUNET_DHT_FindPeerMessage); other_hello = GNUNET_malloc (other_hello_size); memcpy (other_hello, &find_peer_message[1], other_hello_size); if ((GNUNET_HELLO_size ((struct GNUNET_HELLO_Message *) other_hello) == 0) || (GNUNET_OK != GNUNET_HELLO_get_id ((struct GNUNET_HELLO_Message *) other_hello, &peer_id))) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Received invalid HELLO message in find peer request!\n"); GNUNET_free (other_hello); return; } #if FIND_PEER_WITH_HELLO if (GNUNET_YES == consider_peer (&peer_id)) { increment_stats (STAT_HELLOS_PROVIDED); GNUNET_TRANSPORT_offer_hello (transport_handle, other_hello, NULL, NULL); GNUNET_CORE_peer_request_connect (coreAPI, &peer_id, NULL, NULL); route_message (find_msg, msg_ctx); GNUNET_free (other_hello); return; } else /* We don't want this peer! */ { route_message (find_msg, msg_ctx); GNUNET_free (other_hello); return; } #endif } #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request from client, key %s (msg size %d, we expected %d)\n", my_short_id, "DHT", "FIND PEER", GNUNET_h2s (&msg_ctx->key), ntohs (find_msg->size), sizeof (struct GNUNET_MessageHeader)); #endif if (my_hello == NULL) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s': Our HELLO is null, can't return.\n", "DHT"); #endif GNUNET_free_non_null (other_hello); route_message (find_msg, msg_ctx); return; } incoming_bloom = GNUNET_CONTAINER_bloomfilter_init (find_peer_message->bloomfilter, DHT_BLOOM_SIZE, DHT_BLOOM_K); if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (incoming_bloom, &my_identity.hashPubKey)) { increment_stats (STAT_BLOOM_FIND_PEER); GNUNET_CONTAINER_bloomfilter_free (incoming_bloom); GNUNET_free_non_null (other_hello); route_message (find_msg, msg_ctx); return; /* We match the bloomfilter, do not send a response to this peer (they likely already know us!) */ } GNUNET_CONTAINER_bloomfilter_free (incoming_bloom); /** * Ignore any find peer requests from a peer we have seen very recently. */ if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (recent_find_peer_requests, &msg_ctx->key)) /* We have recently responded to a find peer request for this peer! */ { increment_stats ("# dht find peer requests ignored (recently seen!)"); GNUNET_free_non_null (other_hello); return; } /** * Use this check to only allow the peer to respond to find peer requests if * it would be beneficial to have the requesting peer in this peers routing * table. Can be used to thwart peers flooding the network with find peer * requests that we don't care about. However, if a new peer is joining * the network and has no other peers this is a problem (assume all buckets * full, no one will respond!). */ memcpy (&peer_id.hashPubKey, &msg_ctx->key, sizeof (GNUNET_HashCode)); if (GNUNET_NO == consider_peer (&peer_id)) { increment_stats ("# dht find peer requests ignored (do not need!)"); GNUNET_free_non_null (other_hello); route_message (find_msg, msg_ctx); return; } recent_hash = GNUNET_malloc (sizeof (GNUNET_HashCode)); memcpy (recent_hash, &msg_ctx->key, sizeof (GNUNET_HashCode)); if (GNUNET_SYSERR != GNUNET_CONTAINER_multihashmap_put (recent_find_peer_requests, &msg_ctx->key, NULL, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Adding recent remove task for key `%s`!\n", GNUNET_h2s (&msg_ctx->key)); #endif /* Only add a task if there wasn't one for this key already! */ GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30), &remove_recent_find_peer, recent_hash); } else { GNUNET_free (recent_hash); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received duplicate find peer request too soon!\n"); #endif } /* Simplistic find_peer functionality, always return our hello */ hello_size = ntohs (my_hello->size); tsize = hello_size + sizeof (struct GNUNET_MessageHeader); if (tsize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break_op (0); GNUNET_free_non_null (other_hello); return; } find_peer_result = GNUNET_malloc (tsize); find_peer_result->type = htons (GNUNET_MESSAGE_TYPE_DHT_FIND_PEER_RESULT); find_peer_result->size = htons (tsize); memcpy (&find_peer_result[1], my_hello, hello_size); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s': Sending hello size %d to requesting peer.\n", "DHT", hello_size); #endif new_msg_ctx = GNUNET_malloc (sizeof (struct DHT_MessageContext)); memcpy (new_msg_ctx, msg_ctx, sizeof (struct DHT_MessageContext)); new_msg_ctx->peer = my_identity; new_msg_ctx->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K); new_msg_ctx->hop_count = 0; new_msg_ctx->importance = DHT_DEFAULT_P2P_IMPORTANCE + 2; /* Make find peer requests a higher priority */ new_msg_ctx->timeout = DHT_DEFAULT_P2P_TIMEOUT; increment_stats (STAT_FIND_PEER_ANSWER); if (GNUNET_DHT_RO_RECORD_ROUTE == (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE)) { new_msg_ctx->msg_options = GNUNET_DHT_RO_RECORD_ROUTE; new_msg_ctx->path_history_len = msg_ctx->path_history_len; /* Assign to previous msg_ctx path history, caller should free after our return */ new_msg_ctx->path_history = msg_ctx->path_history; } route_result_message (find_peer_result, new_msg_ctx); GNUNET_free (new_msg_ctx); GNUNET_free_non_null (other_hello); GNUNET_free (find_peer_result); route_message (find_msg, msg_ctx); } /** * Server handler for initiating local dht put requests * * @param msg the actual put message * @param msg_ctx struct containing pertinent information about the request */ static void handle_dht_put (const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *msg_ctx) { const struct GNUNET_DHT_PutMessage *put_msg; struct DHTPutEntry *put_entry; unsigned int put_size; char *path_offset; enum GNUNET_BLOCK_Type put_type; size_t data_size; int ret; GNUNET_HashCode key; struct DHTQueryRecord *record; GNUNET_assert (ntohs (msg->size) >= sizeof (struct GNUNET_DHT_PutMessage)); put_msg = (const struct GNUNET_DHT_PutMessage *) msg; put_type = (enum GNUNET_BLOCK_Type) ntohl (put_msg->type); data_size = ntohs (put_msg->header.size) - sizeof (struct GNUNET_DHT_PutMessage); ret = GNUNET_BLOCK_get_key (block_context, put_type, &put_msg[1], data_size, &key); if (GNUNET_NO == ret) { /* invalid reply */ GNUNET_break_op (0); return; } if ((GNUNET_YES == ret) && (0 != memcmp (&key, &msg_ctx->key, sizeof (GNUNET_HashCode)))) { /* invalid wrapper: key mismatch! */ GNUNET_break_op (0); return; } /* ret == GNUNET_SYSERR means that there is no known relationship between * data and the key, so we cannot check it */ #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request (inserting data!), message type %d, key %s, uid %llu\n", my_short_id, "DHT", "PUT", put_type, GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id); #endif record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap, &msg_ctx->key); if (NULL != record) { struct DHTRouteSource *pos; struct GNUNET_DHT_GetResultMessage *get_result; struct DHT_MessageContext new_msg_ctx; size_t get_size; pos = record->head; while (pos != NULL) { /* TODO: do only for local started requests? or also for remote peers? */ /* TODO: include this in statistics? under what? */ /* TODO: reverse order of path_history? */ if (NULL == pos->client) { pos = pos->next; continue; } memcpy (&new_msg_ctx, msg_ctx, sizeof (struct DHT_MessageContext)); if (GNUNET_DHT_RO_RECORD_ROUTE == (msg_ctx->msg_options & GNUNET_DHT_RO_RECORD_ROUTE)) { new_msg_ctx.msg_options = GNUNET_DHT_RO_RECORD_ROUTE; } get_size = sizeof (struct GNUNET_DHT_GetResultMessage) + data_size + (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); get_result = GNUNET_malloc (get_size); get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT); get_result->header.size = htons (get_size); get_result->expiration = put_msg->expiration; get_result->type = put_msg->type; get_result->put_path_length = htons (msg_ctx->path_history_len); /* Copy the actual data and the path_history to the end of the get result */ memcpy (&get_result[1], &put_msg[1], data_size); path_offset = (char *) &get_result[1]; path_offset += data_size; memcpy (path_offset, msg_ctx->path_history, msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); new_msg_ctx.peer = my_identity; new_msg_ctx.bloom = NULL; new_msg_ctx.hop_count = 0; /* Make result routing a higher priority */ new_msg_ctx.importance = DHT_DEFAULT_P2P_IMPORTANCE + 2; new_msg_ctx.timeout = DHT_DEFAULT_P2P_TIMEOUT; new_msg_ctx.unique_id = pos->uid; send_reply_to_client(pos->client, &get_result->header, &new_msg_ctx); GNUNET_free (get_result); pos = pos->next; } } if (msg_ctx->closest != GNUNET_YES) { route_message (msg, msg_ctx); return; } #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request (inserting data!), message type %d, key %s, uid %llu\n", my_short_id, "DHT", "PUT", put_type, GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id); #endif increment_stats (STAT_PUTS_INSERTED); if (datacache != NULL) { /* Put size is actual data size plus struct overhead plus path length (if any) */ put_size = data_size + sizeof (struct DHTPutEntry) + (msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); put_entry = GNUNET_malloc (put_size); put_entry->data_size = data_size; put_entry->path_length = msg_ctx->path_history_len; /* Copy data to end of put entry */ memcpy (&put_entry[1], &put_msg[1], data_size); if (msg_ctx->path_history_len > 0) { /* Copy path after data */ path_offset = (char *) &put_entry[1]; path_offset += data_size; memcpy (path_offset, msg_ctx->path_history, msg_ctx->path_history_len * sizeof (struct GNUNET_PeerIdentity)); } ret = GNUNET_DATACACHE_put (datacache, &msg_ctx->key, put_size, (const char *) put_entry, put_type, GNUNET_TIME_absolute_ntoh (put_msg->expiration)); GNUNET_free (put_entry); } else GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': %s request received, but have no datacache!\n", my_short_id, "DHT", "PUT"); route_message (msg, msg_ctx); } /** * To how many peers should we (on average) * forward the request to obtain the desired * target_replication count (on average). * * returns: target_replication / (est. hops) + (target_replication * hop_count) * where est. hops is typically 2 * the routing table depth * * @param hop_count number of hops the message has traversed * @param target_replication the number of total paths desired * * @return Some number of peers to forward the message to */ static unsigned int get_forward_count (unsigned int hop_count, size_t target_replication) { uint32_t random_value; unsigned int forward_count; float target_value; if (hop_count > log_of_network_size_estimate * 4.0) { /* forcefully terminate */ return 0; } if (hop_count > log_of_network_size_estimate * 2.0) { /* keep forwarding, but no more replication */ return 1; } target_value = 1 + (target_replication - 1.0) / (log_of_network_size_estimate + ((float) (target_replication - 1.0) * hop_count)); /* Set forward count to floor of target_value */ forward_count = (unsigned int) target_value; /* Subtract forward_count (floor) from target_value (yields value between 0 and 1) */ target_value = target_value - forward_count; random_value = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, UINT32_MAX); if (random_value < (target_value * UINT32_MAX)) forward_count++; return forward_count; } /** * Check whether my identity is closer than any known peers. * If a non-null bloomfilter is given, check if this is the closest * peer that hasn't already been routed to. * * @param target hash code to check closeness to * @param bloom bloomfilter, exclude these entries from the decision * @return GNUNET_YES if node location is closest, * GNUNET_NO otherwise. */ static int am_closest_peer (const GNUNET_HashCode * target, struct GNUNET_CONTAINER_BloomFilter *bloom) { int bits; int other_bits; int bucket_num; int count; struct PeerInfo *pos; unsigned int my_distance; if (0 == memcmp (&my_identity.hashPubKey, target, sizeof (GNUNET_HashCode))) return GNUNET_YES; bucket_num = find_current_bucket (target); bits = GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, target); my_distance = distance (&my_identity.hashPubKey, target); pos = k_buckets[bucket_num].head; count = 0; while ((pos != NULL) && (count < bucket_size)) { if ((bloom != NULL) && (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey))) { pos = pos->next; continue; /* Skip already checked entries */ } other_bits = GNUNET_CRYPTO_hash_matching_bits (&pos->id.hashPubKey, target); if (other_bits > bits) return GNUNET_NO; else if (other_bits == bits) /* We match the same number of bits */ { if (distance (&pos->id.hashPubKey, target) < my_distance) /* Check all known peers, only return if we are the true closest */ return GNUNET_NO; } pos = pos->next; } /* No peers closer, we are the closest! */ return GNUNET_YES; } /** * Select a peer from the routing table that would be a good routing * destination for sending a message for "target". The resulting peer * must not be in the set of blocked peers.

* * Note that we should not ALWAYS select the closest peer to the * target, peers further away from the target should be chosen with * exponentially declining probability. * * @param target the key we are selecting a peer to route to * @param bloom a bloomfilter containing entries this request has seen already * @param hops how many hops has this message traversed thus far * * @return Peer to route to, or NULL on error */ static struct PeerInfo * select_peer (const GNUNET_HashCode * target, struct GNUNET_CONTAINER_BloomFilter *bloom, unsigned int hops) { unsigned int bc; unsigned int count; unsigned int selected; struct PeerInfo *pos; unsigned int distance; unsigned int largest_distance; struct PeerInfo *chosen; if (hops >= log_of_network_size_estimate) { /* greedy selection (closest peer that is not in bloomfilter) */ largest_distance = 0; chosen = NULL; for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++) { pos = k_buckets[bc].head; count = 0; while ((pos != NULL) && (count < bucket_size)) { /* If we are doing strict Kademlia routing, then checking the bloomfilter is basically cheating! */ if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) { distance = inverse_distance (target, &pos->id.hashPubKey); if (distance > largest_distance) { chosen = pos; largest_distance = distance; } } count++; pos = pos->next; } } if ((largest_distance > 0) && (chosen != NULL)) { GNUNET_CONTAINER_bloomfilter_add (bloom, &chosen->id.hashPubKey); return chosen; } return NULL; /* no peer available or we are the closest */ } /* select "random" peer */ /* count number of peers that are available and not filtered */ count = 0; for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++) { pos = k_buckets[bc].head; while ((pos != NULL) && (count < bucket_size)) { if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) { pos = pos->next; increment_stats ("# peer blocked from selection by Bloom filter"); continue; /* Ignore bloomfiltered peers */ } count++; pos = pos->next; } } if (count == 0) /* No peers to select from! */ { increment_stats ("# failed to select peer"); return NULL; } /* Now actually choose a peer */ selected = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, count); count = 0; for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++) { pos = k_buckets[bc].head; while ((pos != NULL) && (count < bucket_size)) { if (GNUNET_YES == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) { pos = pos->next; continue; /* Ignore bloomfiltered peers */ } if (0 == selected--) return pos; pos = pos->next; } } GNUNET_break (0); return NULL; } /** * Remember this routing request so that if a reply is * received we can either forward it to the correct peer * or return the result locally. * * @param msg_ctx Context of the route request * * @return GNUNET_YES if this response was cached, GNUNET_NO if not */ static int cache_response (struct DHT_MessageContext *msg_ctx) { struct DHTQueryRecord *record; struct DHTRouteSource *source_info; struct DHTRouteSource *pos; struct GNUNET_TIME_Absolute now; unsigned int current_size; current_size = GNUNET_CONTAINER_multihashmap_size (forward_list.hashmap); while (current_size >= MAX_OUTSTANDING_FORWARDS) { source_info = GNUNET_CONTAINER_heap_remove_root (forward_list.minHeap); GNUNET_assert (source_info != NULL); record = source_info->record; GNUNET_CONTAINER_DLL_remove (record->head, record->tail, source_info); if (record->head == NULL) /* No more entries in DLL */ { GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (forward_list.hashmap, &record->key, record)); GNUNET_free (record); } if (source_info->delete_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (source_info->delete_task); source_info->delete_task = GNUNET_SCHEDULER_NO_TASK; } if (source_info->find_peers_responded != NULL) GNUNET_CONTAINER_bloomfilter_free (source_info->find_peers_responded); GNUNET_free (source_info); current_size = GNUNET_CONTAINER_multihashmap_size (forward_list.hashmap); } /** Non-local request and have too many outstanding forwards, discard! */ if ((current_size >= MAX_OUTSTANDING_FORWARDS) && (msg_ctx->client == NULL)) return GNUNET_NO; now = GNUNET_TIME_absolute_get (); record = GNUNET_CONTAINER_multihashmap_get (forward_list.hashmap, &msg_ctx->key); if (record != NULL) /* Already know this request! */ { pos = record->head; while (pos != NULL) { if (0 == memcmp (&msg_ctx->peer, &pos->source, sizeof (struct GNUNET_PeerIdentity))) break; /* Already have this peer in reply list! */ pos = pos->next; } if ((pos != NULL) && (pos->client == msg_ctx->client)) /* Seen this already */ { GNUNET_CONTAINER_heap_update_cost (forward_list.minHeap, pos->hnode, now.abs_value); return GNUNET_NO; } } else { record = GNUNET_malloc (sizeof (struct DHTQueryRecord)); GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multihashmap_put (forward_list.hashmap, &msg_ctx->key, record, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); memcpy (&record->key, &msg_ctx->key, sizeof (GNUNET_HashCode)); } source_info = GNUNET_malloc (sizeof (struct DHTRouteSource)); source_info->record = record; source_info->delete_task = GNUNET_SCHEDULER_add_delayed (DHT_FORWARD_TIMEOUT, &remove_forward_entry, source_info); source_info->find_peers_responded = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K); source_info->source = msg_ctx->peer; GNUNET_CONTAINER_DLL_insert_after (record->head, record->tail, record->tail, source_info); if (msg_ctx->client != NULL) /* For local request, set timeout so high it effectively never gets pushed out */ { source_info->client = msg_ctx->client; now = GNUNET_TIME_absolute_get_forever (); } source_info->hnode = GNUNET_CONTAINER_heap_insert (forward_list.minHeap, source_info, now.abs_value); source_info->uid = msg_ctx->unique_id; #if DEBUG_DHT > 1 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Created new forward source info for %s uid %llu\n", my_short_id, "DHT", GNUNET_h2s (&msg_ctx->key), msg_ctx->unique_id); #endif return GNUNET_YES; } /** * Main function that handles whether or not to route a message to other * peers. * * @param msg the message to be routed * @param msg_ctx the context containing all pertinent information about the message */ static void route_message (const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *msg_ctx) { int i; struct PeerInfo *selected; unsigned int target_forward_count; unsigned int forward_count; struct RecentRequest *recent_req; char *stat_forward_count; char *temp_stat_str; increment_stats (STAT_ROUTES); target_forward_count = get_forward_count (msg_ctx->hop_count, msg_ctx->replication); GNUNET_asprintf (&stat_forward_count, "# forward counts of %d", target_forward_count); increment_stats (stat_forward_count); GNUNET_free (stat_forward_count); if (msg_ctx->bloom == NULL) msg_ctx->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K); if (GNUNET_CONTAINER_heap_get_size (recent_heap) >= DHT_MAX_RECENT) { recent_req = GNUNET_CONTAINER_heap_peek (recent_heap); GNUNET_assert (recent_req != NULL); GNUNET_SCHEDULER_cancel (recent_req->remove_task); GNUNET_CONTAINER_heap_remove_node (recent_req->heap_node); GNUNET_CONTAINER_bloomfilter_free (recent_req->bloom); GNUNET_free (recent_req); } recent_req = GNUNET_malloc (sizeof (struct RecentRequest)); recent_req->uid = msg_ctx->unique_id; memcpy (&recent_req->key, &msg_ctx->key, sizeof (GNUNET_HashCode)); recent_req->heap_node = GNUNET_CONTAINER_heap_insert (recent_heap, recent_req, GNUNET_TIME_absolute_get ().abs_value); recent_req->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K); forward_count = 0; for (i = 0; i < target_forward_count; i++) { selected = select_peer (&msg_ctx->key, msg_ctx->bloom, msg_ctx->hop_count); if (selected == NULL) break; forward_count++; if (GNUNET_CRYPTO_hash_matching_bits (&selected->id.hashPubKey, &msg_ctx->key) >= GNUNET_CRYPTO_hash_matching_bits (&my_identity.hashPubKey, &msg_ctx->key)) GNUNET_asprintf (&temp_stat_str, "# requests routed to close(r) peer hop %u", msg_ctx->hop_count); else GNUNET_asprintf (&temp_stat_str, "# requests routed to less close peer hop %u", msg_ctx->hop_count); if (temp_stat_str != NULL) { increment_stats (temp_stat_str); GNUNET_free (temp_stat_str); } GNUNET_CONTAINER_bloomfilter_add (msg_ctx->bloom, &selected->id.hashPubKey); forward_message (msg, selected, msg_ctx); } if (msg_ctx->bloom != NULL) { GNUNET_CONTAINER_bloomfilter_or2 (recent_req->bloom, msg_ctx->bloom, DHT_BLOOM_SIZE); GNUNET_CONTAINER_bloomfilter_free (msg_ctx->bloom); msg_ctx->bloom = NULL; } } /** * Main function that handles whether or not to route a message to other * peers. * * @param msg the message to be routed * @param msg_ctx the context containing all pertinent information about the message */ static void demultiplex_message (const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *msg_ctx) { /* FIXME: Should we use closest excluding those we won't route to (the bloomfilter problem)? */ msg_ctx->closest = am_closest_peer (&msg_ctx->key, msg_ctx->bloom); switch (ntohs (msg->type)) { case GNUNET_MESSAGE_TYPE_DHT_GET: /* Add to hashmap of requests seen, search for data (always) */ cache_response (msg_ctx); handle_dht_get (msg, msg_ctx); break; case GNUNET_MESSAGE_TYPE_DHT_PUT: /* Check if closest, if so insert data. */ increment_stats (STAT_PUTS); handle_dht_put (msg, msg_ctx); break; case GNUNET_MESSAGE_TYPE_DHT_FIND_PEER: /* Check if closest and not started by us, check options, add to requests seen */ increment_stats (STAT_FIND_PEER); if (((msg_ctx->hop_count > 0) && (0 != memcmp (&msg_ctx->peer, &my_identity, sizeof (struct GNUNET_PeerIdentity)))) || (msg_ctx->client != NULL)) { cache_response (msg_ctx); if ((msg_ctx->closest == GNUNET_YES) || (msg_ctx->msg_options == GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) handle_dht_find_peer (msg, msg_ctx); } else route_message (msg, msg_ctx); break; default: GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "`%s': Message type (%d) not handled, forwarding anyway!\n", "DHT", ntohs (msg->type)); route_message (msg, msg_ctx); } } /** * Receive the HELLO from transport service, * free current and replace if necessary. * * @param cls NULL * @param message HELLO message of peer */ static void process_hello (void *cls, const struct GNUNET_MessageHeader *message) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received our `%s' from transport service\n", "HELLO"); #endif GNUNET_assert (message != NULL); GNUNET_free_non_null (my_hello); my_hello = GNUNET_malloc (ntohs (message->size)); memcpy (my_hello, message, ntohs (message->size)); } /** * Task run during shutdown. * * @param cls unused * @param tc unused */ static void shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { int bucket_count; struct PeerInfo *pos; if (NULL != ghh) { GNUNET_TRANSPORT_get_hello_cancel (ghh); ghh = NULL; } if (transport_handle != NULL) { GNUNET_free_non_null (my_hello); GNUNET_TRANSPORT_disconnect (transport_handle); transport_handle = NULL; } GDS_NEIGHBOURS_done (); GDS_NSE_done (); for (bucket_count = lowest_bucket; bucket_count < MAX_BUCKETS; bucket_count++) { while (k_buckets[bucket_count].head != NULL) { pos = k_buckets[bucket_count].head; #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Removing peer %s from bucket %d!\n", my_short_id, "DHT", GNUNET_i2s (&pos->id), bucket_count); #endif delete_peer (pos, bucket_count); } } if (datacache != NULL) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Destroying datacache!\n", my_short_id, "DHT"); #endif GNUNET_DATACACHE_destroy (datacache); datacache = NULL; } if (stats != NULL) { GNUNET_STATISTICS_destroy (stats, GNUNET_YES); stats = NULL; } if (block_context != NULL) { GNUNET_BLOCK_context_destroy (block_context); block_context = NULL; } } /** * Process dht requests. * * @param cls closure * @param server the initialized server * @param c configuration to use */ static void run (void *cls, struct GNUNET_SERVER_Handle *server, const struct GNUNET_CONFIGURATION_Handle *c) { struct GNUNET_TIME_Relative next_send_time; unsigned long long temp_config_num; cfg = c; datacache = GNUNET_DATACACHE_create (cfg, "dhtcache"); coreAPI = GNUNET_CORE_connect (cfg, /* Main configuration */ DEFAULT_CORE_QUEUE_SIZE, /* queue size */ NULL, /* Closure passed to DHT functions */ &core_init, /* Call core_init once connected */ &handle_core_connect, /* Handle connects */ &handle_core_disconnect, /* remove peers on disconnects */ NULL, /* Do we care about "status" updates? */ NULL, /* Don't want notified about all incoming messages */ GNUNET_NO, /* For header only inbound notification */ NULL, /* Don't want notified about all outbound messages */ GNUNET_NO, /* For header only outbound notification */ core_handlers); /* Register these handlers */ if (coreAPI == NULL) return; transport_handle = GNUNET_TRANSPORT_connect (cfg, NULL, NULL, NULL, NULL, NULL); if (transport_handle != NULL) ghh = GNUNET_TRANSPORT_get_hello (transport_handle, &process_hello, NULL); else GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Failed to connect to transport service!\n"); block_context = GNUNET_BLOCK_context_create (cfg); lowest_bucket = MAX_BUCKETS - 1; all_known_peers = GNUNET_CONTAINER_multihashmap_create (MAX_BUCKETS / 8); GNUNET_assert (all_known_peers != NULL); if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (cfg, "DHT", "bucket_size", &temp_config_num)) { bucket_size = (unsigned int) temp_config_num; } stats = GNUNET_STATISTICS_create ("dht", cfg); next_send_time.rel_value = DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value + GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_STRONG, (DHT_MAXIMUM_FIND_PEER_INTERVAL.rel_value / 2) - DHT_MINIMUM_FIND_PEER_INTERVAL.rel_value); find_peer_context.start = GNUNET_TIME_absolute_get (); GNUNET_SCHEDULER_add_delayed (next_send_time, &send_find_peer_message, &find_peer_context); /* Scheduled the task to clean up when shutdown is called */ cleanup_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &shutdown_task, NULL); } /** * The main function for the dht service. * * @param argc number of arguments from the command line * @param argv command line arguments * @return 0 ok, 1 on error */ int main (int argc, char *const *argv) { int ret; struct RecentRequest *recent_req; recent_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN); recent_find_peer_requests = GNUNET_CONTAINER_multihashmap_create (MAX_BUCKETS / 8); ret = (GNUNET_OK == GNUNET_SERVICE_run (argc, argv, "dht", GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1; while (GNUNET_CONTAINER_heap_get_size (recent_heap) > 0) { recent_req = GNUNET_CONTAINER_heap_peek (recent_heap); GNUNET_assert (recent_req != NULL); GNUNET_CONTAINER_heap_remove_node (recent_req->heap_node); GNUNET_CONTAINER_bloomfilter_free (recent_req->bloom); GNUNET_free (recent_req); } GNUNET_CONTAINER_heap_destroy (recent_heap); recent_heap = NULL; GNUNET_CONTAINER_multihashmap_destroy (recent_find_peer_requests); recent_find_peer_requests = NULL; return ret; } /* end of gnunet-service-dht.c */