/* This file is part of GNUnet. (C) 2009, 2010 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 main DHT service shell, building block for DHT implementations * @author Christian Grothoff * @author Nathan Evans */ #include "platform.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_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 "dhtlog.h" #include "dht.h" #define PRINT_TABLES GNUNET_NO #define EXTRA_CHECKS GNUNET_YES /** * How many buckets will we allow total. */ #define MAX_BUCKETS sizeof (GNUNET_HashCode) * 8 /** * Should the DHT issue FIND_PEER requests to get better routing tables? */ #define DO_FIND_PEER GNUNET_YES /** * What is the maximum number of peers in a given bucket. */ #define DEFAULT_BUCKET_SIZE 8 /** * 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 #define DHT_DEFAULT_FIND_PEER_REPLICATION 20 #define DHT_DEFAULT_FIND_PEER_OPTIONS GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE #define DHT_DEFAULT_FIND_PEER_INTERVAL GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 1) /** * Real maximum number of hops, at which point we refuse * to forward the message. */ #define MAX_HOPS 20 /** * Linked list of messages to send to clients. */ struct P2PPendingMessage { /** * Pointer to next item in the list */ struct P2PPendingMessage *next; /** * Pointer to previous item in the list */ struct P2PPendingMessage *prev; /** * Message importance level. */ unsigned int importance; /** * How long to wait before sending message. */ struct GNUNET_TIME_Relative timeout; /** * Actual message to be sent; // avoid allocation */ const struct GNUNET_MessageHeader *msg; // msg = (cast) &pm[1]; // memcpy (&pm[1], data, len); }; /** * Per-peer information. */ struct PeerInfo { /** * Next peer entry (DLL) */ struct PeerInfo *next; /** * Prev peer entry (DLL) */ struct PeerInfo *prev; /** * Head of pending messages to be sent to this peer. */ struct P2PPendingMessage *head; /** * Tail of pending messages to be sent to this peer. */ struct P2PPendingMessage *tail; /** * Core handle for sending messages to this peer. */ struct GNUNET_CORE_TransmitHandle *th; /** * Task for scheduling message sends. */ GNUNET_SCHEDULER_TaskIdentifier send_task; /** * What is the average latency for replies received? */ struct GNUNET_TIME_Relative latency; /** * Number of responses received */ unsigned long long response_count; /** * Number of requests sent */ unsigned long long request_count; /** * What is the identity of the peer? */ struct GNUNET_PeerIdentity id; /** * Transport level distance to peer. */ unsigned int distance; }; /** * Peers are grouped into buckets. */ struct PeerBucket { /** * Head of DLL */ struct PeerInfo *head; /** * Tail of DLL */ struct PeerInfo *tail; /** * Number of peers in the bucket. */ unsigned int peers_size; }; /** * Linked list of messages to send to clients. */ struct PendingMessage { /** * Pointer to next item in the list */ struct PendingMessage *next; /** * Pointer to previous item in the list */ struct PendingMessage *prev; /** * Actual message to be sent; // avoid allocation */ const struct GNUNET_MessageHeader *msg; // msg = (cast) &pm[1]; // memcpy (&pm[1], data, len); }; /** * Struct containing information about a client, * handle to connect to it, and any pending messages * that need to be sent to it. */ struct ClientList { /** * Linked list of active clients */ struct ClientList *next; /** * The handle to this client */ struct GNUNET_SERVER_Client *client_handle; /** * Handle to the current transmission request, NULL * if none pending. */ struct GNUNET_CONNECTION_TransmitHandle *transmit_handle; /** * Linked list of pending messages for this client */ struct PendingMessage *pending_head; /** * Tail of linked list of pending messages for this client */ struct PendingMessage *pending_tail; }; /** * 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. * (NULL if received from local client) */ const struct GNUNET_PeerIdentity *peer; /** * The key this request was about */ const GNUNET_HashCode *key; /** * The unique identifier of this request */ uint64_t unique_id; /** * 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; /** * Bloomfilter for this routing request. */ struct GNUNET_CONTAINER_BloomFilter *bloom; /** * 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; /** * 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; }; /** * 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; /** * GET message of this record (what we already forwarded?). */ //DV_DHT_MESSAGE get; Try to get away with not saving this. /** * Bloomfilter of the peers we've replied to so far */ //struct GNUNET_BloomFilter *bloom_results; Don't think we need this, just remove from DLL on response. }; /** * DHT Routing results structure */ struct DHTResults { /* * Min heap for removal upon reaching limit */ struct GNUNET_CONTAINER_Heap *minHeap; /* * Hashmap for fast key based lookup */ struct GNUNET_CONTAINER_MultiHashMap *hashmap; }; /** * Routing option to end routing when closest peer found. */ static int stop_on_closest; /** * Routing option to end routing when data is found. */ static int stop_on_found; /** * Container of active queries we should remember */ static struct DHTResults forward_list; /** * Handle to the datacache service (for inserting/retrieving data) */ static struct GNUNET_DATACACHE_Handle *datacache; /** * The main scheduler to use for the DHT service */ static struct GNUNET_SCHEDULER_Handle *sched; /** * 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; /** * The lowest currently used bucket. */ static unsigned int lowest_bucket; /* Initially equal to MAX_BUCKETS - 1 */ /** * The buckets (Kademlia routing table, complete with growth). * Array of size MAX_BUCKET_SIZE. */ static struct PeerBucket k_buckets[MAX_BUCKETS]; /* From 0 to MAX_BUCKETS - 1 */ /** * Hash map of all known peers, for easy removal from k_buckets on disconnect. */ static struct GNUNET_CONTAINER_MultiHashMap *all_known_peers; /** * Maximum size for each bucket. */ static unsigned int bucket_size = DEFAULT_BUCKET_SIZE; /* Initially equal to DEFAULT_BUCKET_SIZE */ /** * List of active clients. */ static struct ClientList *client_list; /** * Handle to the DHT logger. */ static struct GNUNET_DHTLOG_Handle *dhtlog_handle; /* * Whether or not to send routing debugging information * to the dht logging server */ static unsigned int debug_routes; /* * Whether or not to send FULL route information to * logging server */ static unsigned int debug_routes_extended; /** * Forward declaration. */ static size_t send_generic_reply (void *cls, size_t size, void *buf); /* Declare here so retry_core_send is aware of it */ size_t core_transmit_notify (void *cls, size_t size, void *buf); /** * 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) 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 peer->th = GNUNET_CORE_notify_transmit_ready(coreAPI, pending->importance, pending->timeout, &peer->id, ssize, &core_transmit_notify, peer); } } /** * Function called to send a request out to another peer. * Called both for locally initiated requests and those * received from other peers. * * @param cls DHT service closure argument * @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 (void *cls, 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; msize = sizeof (struct GNUNET_DHT_P2PRouteResultMessage) + ntohs(msg->size); 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->options = htonl(msg_ctx->msg_options); result_message->hop_count = htonl(msg_ctx->hop_count + 1); GNUNET_assert(GNUNET_OK == GNUNET_CONTAINER_bloomfilter_get_raw_data(msg_ctx->bloom, result_message->bloomfilter, DHT_BLOOM_SIZE)); result_message->unique_id = GNUNET_htonll(msg_ctx->unique_id); memcpy(&result_message->key, msg_ctx->key, sizeof(GNUNET_HashCode)); memcpy(&result_message[1], msg, ntohs(msg->size)); #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 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(sched, &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 */ 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; 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; peer->th = NULL; off = 0; pending = peer->head; msize = ntohs(pending->msg->size); if (msize <= size) { off = msize; memcpy (cbuf, pending->msg, msize); GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending); #if DEBUG_DHT > 1 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "%s:%s Removing pending message size %d for peer %s\n", my_short_id, "DHT", msize, GNUNET_i2s(&peer->id)); #endif GNUNET_free (pending); } #if SMART while (NULL != pending && (size - off >= (msize = ntohs (pending->msg->size)))) { #if DEBUG_DHT_ROUTING GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "`%s:%s' : transmit_notify (core) called with size %d, available %d\n", my_short_id, "dht service", msize, size); #endif memcpy (&cbuf[off], pending->msg, msize); off += msize; GNUNET_CONTAINER_DLL_remove (peer->head, peer->tail, pending); GNUNET_free (pending); pending = peer->head; } #endif if ((peer->head != NULL) && (peer->send_task == GNUNET_SCHEDULER_NO_TASK)) peer->send_task = GNUNET_SCHEDULER_add_now(sched, &try_core_send, peer); #if DEBUG_DHT > 1 GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "`%s:%s' : transmit_notify (core) called with size %d, available %d, returning %d\n", my_short_id, "dht service", msize, size, off); #endif return off; } /** * Determine how many low order bits match in two * GNUNET_HashCodes. i.e. - 010011 and 011111 share * the first two lowest order bits, and therefore the * return value is two (NOT XOR distance, nor how many * bits match absolutely!). * * @param first the first hashcode * @param second the hashcode to compare first to * * @return the number of bits that match */ static unsigned int matching_bits(const GNUNET_HashCode *first, const GNUNET_HashCode *second) { unsigned int i; for (i = 0; i < sizeof (GNUNET_HashCode) * 8; i++) if (GNUNET_CRYPTO_hash_get_bit (first, i) != GNUNET_CRYPTO_hash_get_bit (second, i)) return i; return sizeof (GNUNET_HashCode) * 8; } /** * 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 = 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 (matching_bits(target, have) == 0) return 1; /* Never return 0! */ return ((unsigned int) -1) - distance (target, have); } /** * Find the optimal bucket for this key, regardless * of the current number of buckets in use. * * @param hc the hashcode to compare our identity to * * @return the proper bucket index, or GNUNET_SYSERR * on error (same hashcode) */ static int find_bucket(const GNUNET_HashCode *hc) { unsigned int bits; bits = matching_bits(&my_identity.hashPubKey, hc); if (bits == MAX_BUCKETS) return GNUNET_SYSERR; return MAX_BUCKETS - bits - 1; } /** * 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 GNUNET_SYSERR; else if (actual_bucket < lowest_bucket) /* actual_bucket not yet used */ return lowest_bucket; else return actual_bucket; } /** * Find a routing table entry from a peer identity * * @param peer the peer to look up * * @return the bucket number holding the peer, GNUNET_SYSERR if not found */ static int find_bucket_by_peer(const struct PeerInfo *peer) { int bucket; struct PeerInfo *pos; for (bucket = lowest_bucket; bucket < MAX_BUCKETS - 1; bucket++) { pos = k_buckets[bucket].head; while (pos != NULL) { if (peer == pos) return bucket; pos = pos->next; } } return GNUNET_SYSERR; /* No such peer. */ } #if PRINT_TABLES /** * Print the complete routing table for this peer. */ static void print_routing_table () { int bucket; struct PeerInfo *pos; char char_buf[30000]; int char_pos; memset(char_buf, 0, sizeof(char_buf)); char_pos = 0; char_pos += sprintf(&char_buf[char_pos], "Printing routing table for peer %s\n", my_short_id); //fprintf(stderr, "Printing routing table for peer %s\n", my_short_id); for (bucket = lowest_bucket; bucket < MAX_BUCKETS; bucket++) { pos = k_buckets[bucket].head; char_pos += sprintf(&char_buf[char_pos], "Bucket %d:\n", bucket); //fprintf(stderr, "Bucket %d:\n", bucket); while (pos != NULL) { //fprintf(stderr, "\tPeer %s, best bucket %d, %d bits match\n", GNUNET_i2s(&pos->id), find_bucket(&pos->id.hashPubKey), matching_bits(&pos->id.hashPubKey, &my_identity.hashPubKey)); char_pos += sprintf(&char_buf[char_pos], "\tPeer %s, best bucket %d, %d bits match\n", GNUNET_i2s(&pos->id), find_bucket(&pos->id.hashPubKey), matching_bits(&pos->id.hashPubKey, &my_identity.hashPubKey)); pos = pos->next; } } fprintf(stderr, "%s", char_buf); fflush(stderr); } #endif /** * 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 (bucket == GNUNET_SYSERR) 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. */ } /** * Really add a peer to a bucket (only do assertions * on size, etc.) * * @param peer GNUNET_PeerIdentity of the peer to add * @param bucket the already figured out bucket to add * the peer to * @param latency the core reported latency of this peer * @param distance the transport level distance to this peer * * @return the newly added PeerInfo */ static struct PeerInfo * add_peer(const struct GNUNET_PeerIdentity *peer, unsigned int bucket, struct GNUNET_TIME_Relative latency, unsigned int distance) { struct PeerInfo *new_peer; GNUNET_assert(bucket < MAX_BUCKETS); GNUNET_assert(peer != NULL); new_peer = GNUNET_malloc(sizeof(struct PeerInfo)); new_peer->latency = latency; new_peer->distance = distance; memcpy(&new_peer->id, peer, sizeof(struct GNUNET_PeerIdentity)); GNUNET_CONTAINER_DLL_insert_after(k_buckets[bucket].head, k_buckets[bucket].tail, k_buckets[bucket].tail, new_peer); k_buckets[bucket].peers_size++; return new_peer; } /** * Given a peer and its corresponding bucket, * remove it from that bucket. Does not free * the PeerInfo struct, nor cancel messages * or free messages waiting to be sent to this * peer! * * @param peer the peer to remove * @param bucket the bucket the peer belongs to */ static void remove_peer (struct PeerInfo *peer, unsigned int bucket) { GNUNET_assert(k_buckets[bucket].peers_size > 0); GNUNET_CONTAINER_DLL_remove(k_buckets[bucket].head, k_buckets[bucket].tail, peer); k_buckets[bucket].peers_size--; if ((bucket == lowest_bucket) && (k_buckets[lowest_bucket].peers_size == 0) && (lowest_bucket < MAX_BUCKETS - 1)) lowest_bucket++; } /** * Removes peer from a bucket, then frees associated * resources and frees peer. * * @param peer peer to be removed and freed * @param bucket which bucket this peer belongs to */ static void delete_peer (struct PeerInfo *peer, unsigned int bucket) { struct P2PPendingMessage *pos; struct P2PPendingMessage *next; //fprintf(stderr, "BEFORE REMOVAL\n"); //print_routing_table(); #if EXTRA_CHECKS struct PeerInfo *peer_pos; peer_pos = k_buckets[bucket].head; while ((peer_pos != NULL) && (peer_pos != peer)) peer_pos = peer_pos->next; if (peer_pos == NULL) { GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "%s:%s: Expected peer `%s' in bucket %d\n", my_short_id, "DHT", GNUNET_i2s(&peer->id), bucket); GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "%s:%s: Lowest bucket: %d, find_current_bucket: %d, peer resides in bucket: %d\n", my_short_id, "DHT", lowest_bucket, find_current_bucket(&peer->id.hashPubKey), find_bucket_by_peer(peer)); } GNUNET_assert(peer_pos != NULL); #endif remove_peer(peer, bucket); /* First remove the peer from its bucket */ if (peer->send_task != GNUNET_SCHEDULER_NO_TASK) GNUNET_SCHEDULER_cancel(sched, peer->send_task); if (peer->th != NULL) GNUNET_CORE_notify_transmit_ready_cancel(peer->th); pos = peer->head; while (pos != NULL) /* Remove any pending messages for this peer */ { next = pos->next; GNUNET_free(pos); pos = next; } GNUNET_assert(GNUNET_CONTAINER_multihashmap_contains(all_known_peers, &peer->id.hashPubKey)); GNUNET_assert(GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (all_known_peers, &peer->id.hashPubKey, peer)); GNUNET_free(peer); //fprintf(stderr, "AFTER REMOVAL\n"); //print_routing_table(); } /** * Iterator over hash map entries. * * @param cls closure * @param key current key code * @param value PeerInfo of the peer to move to new lowest bucket * @return GNUNET_YES if we should continue to * iterate, * GNUNET_NO if not. */ static int move_lowest_bucket (void *cls, const GNUNET_HashCode * key, void *value) { struct PeerInfo *peer = value; int new_bucket; new_bucket = lowest_bucket - 1; remove_peer(peer, lowest_bucket); GNUNET_CONTAINER_DLL_insert_after(k_buckets[new_bucket].head, k_buckets[new_bucket].tail, k_buckets[new_bucket].tail, peer); k_buckets[new_bucket].peers_size++; return GNUNET_YES; } /** * The current lowest bucket is full, so change the lowest * bucket to the next lower down, and move any appropriate * entries in the current lowest bucket to the new bucket. */ static void enable_next_bucket() { struct GNUNET_CONTAINER_MultiHashMap *to_remove; struct PeerInfo *pos; GNUNET_assert(lowest_bucket > 0); to_remove = GNUNET_CONTAINER_multihashmap_create(bucket_size); pos = k_buckets[lowest_bucket].head; #if PRINT_TABLES fprintf(stderr, "Printing RT before new bucket\n"); print_routing_table(); #endif /* Populate the array of peers which should be in the next lowest bucket */ while (pos != NULL) { if (find_bucket(&pos->id.hashPubKey) < lowest_bucket) GNUNET_CONTAINER_multihashmap_put(to_remove, &pos->id.hashPubKey, pos, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); pos = pos->next; } /* Remove peers from lowest bucket, insert into next lowest bucket */ GNUNET_CONTAINER_multihashmap_iterate(to_remove, &move_lowest_bucket, NULL); lowest_bucket = lowest_bucket - 1; #if PRINT_TABLES fprintf(stderr, "Printing RT after new bucket\n"); print_routing_table(); #endif } /** * Attempt to add a peer to our k-buckets. * * @param peer, the peer identity of the peer being added * * @return NULL if the peer was not added, * pointer to PeerInfo for new peer otherwise */ static struct PeerInfo * try_add_peer(const struct GNUNET_PeerIdentity *peer, unsigned int bucket, struct GNUNET_TIME_Relative latency, unsigned int distance) { int peer_bucket; struct PeerInfo *new_peer; peer_bucket = find_current_bucket(&peer->hashPubKey); if (peer_bucket == GNUNET_SYSERR) return NULL; GNUNET_assert(peer_bucket >= lowest_bucket); new_peer = add_peer(peer, peer_bucket, latency, distance); if ((k_buckets[lowest_bucket].peers_size) >= bucket_size) enable_next_bucket(); return new_peer; } /** * Task run to check for messages that need to be sent to a client. * * @param client a ClientList, containing the client and any messages to be sent to it */ static void process_pending_messages (struct ClientList *client) { if (client->pending_head == NULL) return; if (client->transmit_handle != NULL) return; client->transmit_handle = GNUNET_SERVER_notify_transmit_ready (client->client_handle, ntohs (client->pending_head->msg-> size), GNUNET_TIME_UNIT_FOREVER_REL, &send_generic_reply, client); } /** * Callback called as a result of issuing a GNUNET_SERVER_notify_transmit_ready * request. A ClientList is passed as closure, take the head of the list * and copy it into buf, which has the result of sending the message to the * client. * * @param cls closure to this call * @param size maximum number of bytes available to send * @param buf where to copy the actual message to * * @return the number of bytes actually copied, 0 indicates failure */ static size_t send_generic_reply (void *cls, size_t size, void *buf) { struct ClientList *client = cls; char *cbuf = buf; struct PendingMessage *reply; size_t off; size_t msize; client->transmit_handle = NULL; if (buf == NULL) { /* client disconnected */ return 0; } off = 0; while ( (NULL != (reply = client->pending_head)) && (size >= off + (msize = ntohs (reply->msg->size)))) { GNUNET_CONTAINER_DLL_remove (client->pending_head, client->pending_tail, reply); memcpy (&cbuf[off], reply->msg, msize); GNUNET_free (reply); off += msize; } process_pending_messages (client); return off; } /** * Add a PendingMessage to the clients list of messages to be sent * * @param client the active client to send the message to * @param pending_message the actual message to send */ static void add_pending_message (struct ClientList *client, struct PendingMessage *pending_message) { GNUNET_CONTAINER_DLL_insert_after (client->pending_head, client->pending_tail, client->pending_tail, pending_message); process_pending_messages (client); } /** * 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 uid the unique identifier of this request */ static void send_reply_to_client (struct ClientList *client, const struct GNUNET_MessageHeader *message, unsigned long long uid) { struct GNUNET_DHT_RouteResultMessage *reply; struct PendingMessage *pending_message; uint16_t msize; size_t tsize; #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; 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->unique_id = GNUNET_htonll (uid); memcpy (&reply[1], message, msize); 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) * * FIXME: Think about making a context for this call so that we can * ping the oldest peer in the current bucket and consider * removing it in lieu of the new peer. */ static int consider_peer (struct GNUNET_PeerIdentity *peer) { int bucket; 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; } /** * 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 * @return the number of peers the message was routed to, * GNUNET_SYSERR on failure */ static int route_result_message(void *cls, struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *message_context) { struct GNUNET_PeerIdentity new_peer; struct DHTQueryRecord *record; struct DHTRouteSource *pos; struct PeerInfo *peer_info; const struct GNUNET_MessageHeader *hello_msg; /** * If a find peer result message is received and contains a valid * HELLO for another peer, offer it to the transport service. * * FIXME: Check whether we need this peer (based on routing table * fullness) and only try to connect to it conditionally. This should * reduce trying to connect to say (500) peers when the bucket size will * discard most of them. */ 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); } else /* We have a valid hello, and peer id stored in new_peer */ { if (GNUNET_YES == consider_peer(&new_peer)) { GNUNET_TRANSPORT_offer_hello(transport_handle, hello_msg); /* GNUNET_CORE_peer_request_connect(sched, cfg, GNUNET_TIME_UNIT_FOREVER_REL, &new_peer, NULL, NULL); */ /* peer_request_connect call causes service to segfault */ /* FIXME: Do we need this (peer_request_connect call)??? */ } } } record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap, message_context->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 (message_context->key), message_context->unique_id); #endif #if DEBUG_DHT_ROUTING if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_RESULT, message_context->hop_count, GNUNET_SYSERR, &my_identity, message_context->key, message_context->peer, NULL); } #endif if (message_context->bloom != NULL) { GNUNET_CONTAINER_bloomfilter_free(message_context->bloom); message_context->bloom = NULL; } 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 (message_context->key), message_context->unique_id); #endif #if DEBUG_DHT_ROUTING if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_RESULT, message_context->hop_count, GNUNET_YES, &my_identity, message_context->key, message_context->peer, NULL); } #endif send_reply_to_client(pos->client, msg, message_context->unique_id); } 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 (message_context->bloom == NULL) message_context->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K); GNUNET_CONTAINER_bloomfilter_add (message_context->bloom, &my_identity.hashPubKey); if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (message_context->bloom, &peer_info->id.hashPubKey)) { #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 (message_context->key), message_context->unique_id, GNUNET_i2s(&peer_info->id)); #endif #if DEBUG_DHT_ROUTING if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_RESULT, message_context->hop_count, GNUNET_NO, &my_identity, message_context->key, message_context->peer, &pos->source); } #endif forward_result_message(cls, msg, peer_info, message_context); } else { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': NOT Forwarding response (bloom match) key %s uid %llu to peer %s\n", my_short_id, "DHT", GNUNET_h2s (message_context->key), message_context->unique_id, GNUNET_i2s(&peer_info->id)); #endif } } pos = pos->next; } if (message_context->bloom != NULL) GNUNET_CONTAINER_bloomfilter_free(message_context->bloom); 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, uint32_t size, const char *data, uint32_t type) { struct DHT_MessageContext *msg_ctx = cls; struct DHT_MessageContext *new_msg_ctx; struct GNUNET_DHT_GetResultMessage *get_result; #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' response from datacache\n", my_short_id, "DHT", "GET"); #endif new_msg_ctx = GNUNET_malloc(sizeof(struct DHT_MessageContext)); memcpy(new_msg_ctx, msg_ctx, sizeof(struct DHT_MessageContext)); get_result = GNUNET_malloc (sizeof (struct GNUNET_DHT_GetResultMessage) + size); get_result->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_GET_RESULT); get_result->header.size = htons (sizeof (struct GNUNET_DHT_GetResultMessage) + size); get_result->expiration = GNUNET_TIME_absolute_hton(exp); get_result->type = htons (type); memcpy (&get_result[1], data, size); 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; route_result_message(cls, &get_result->header, new_msg_ctx); GNUNET_free(new_msg_ctx); //send_reply_to_client (datacache_get_ctx->client, &get_result->header, // datacache_get_ctx->unique_id); GNUNET_free (get_result); return GNUNET_OK; } /** * Server handler for all dht get requests, look for data, * if found, send response either to clients or other peers. * * @param cls closure for service * @param msg the actual get message * @param message_context struct containing pertinent information about the get request * * @return number of items found for GET request */ static unsigned int handle_dht_get (void *cls, const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *message_context) { const struct GNUNET_DHT_GetMessage *get_msg; uint16_t get_type; unsigned int results; get_msg = (const struct GNUNET_DHT_GetMessage *) msg; if (ntohs (get_msg->header.size) != sizeof (struct GNUNET_DHT_GetMessage)) { GNUNET_break (0); return 0; } get_type = ntohs (get_msg->type); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request from client, message type %u, key %s, uid %llu\n", my_short_id, "DHT", "GET", get_type, GNUNET_h2s (message_context->key), message_context->unique_id); #endif results = 0; if (datacache != NULL) results = GNUNET_DATACACHE_get (datacache, message_context->key, get_type, &datacache_get_iterator, message_context); if (results >= 1) { #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", message_context->unique_id); #endif #if DEBUG_DHT_ROUTING if ((debug_routes) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_GET, message_context->hop_count, GNUNET_YES, &my_identity, message_context->key); } if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE, message_context->hop_count, GNUNET_YES, &my_identity, message_context->key, message_context->peer, NULL); } #endif } if (message_context->hop_count == 0) /* Locally initiated request */ { #if DEBUG_DHT_ROUTING if ((debug_routes) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_GET, message_context->hop_count, GNUNET_NO, &my_identity, message_context->key); } #endif } return results; } /** * Server handler for initiating local dht find peer requests * * @param cls closure for service * @param find_msg the actual find peer message * @param message_context struct containing pertinent information about the request * */ static void handle_dht_find_peer (void *cls, const struct GNUNET_MessageHeader *find_msg, struct DHT_MessageContext *message_context) { struct GNUNET_MessageHeader *find_peer_result; struct DHT_MessageContext *new_msg_ctx; size_t hello_size; size_t tsize; #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 (message_context->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 return; } /* 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); 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); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s': Sending hello size %d to requesting peer.\n", "DHT", hello_size); new_msg_ctx = GNUNET_malloc(sizeof(struct DHT_MessageContext)); memcpy(new_msg_ctx, message_context, 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; route_result_message(cls, find_peer_result, new_msg_ctx); #if DEBUG_DHT_ROUTING if ((debug_routes) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_FIND_PEER, message_context->hop_count, GNUNET_YES, &my_identity, message_context->key); } #endif //send_reply_to_client(message_context->client, find_peer_result, message_context->unique_id); GNUNET_free(find_peer_result); } /** * Server handler for initiating local dht put requests * * @param cls closure for service * @param msg the actual put message * @param message_context struct containing pertinent information about the request */ static void handle_dht_put (void *cls, const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *message_context) { struct GNUNET_DHT_PutMessage *put_msg; size_t put_type; size_t data_size; GNUNET_assert (ntohs (msg->size) >= sizeof (struct GNUNET_DHT_PutMessage)); put_msg = (struct GNUNET_DHT_PutMessage *)msg; put_type = ntohs (put_msg->type); data_size = ntohs (put_msg->header.size) - sizeof (struct GNUNET_DHT_PutMessage); #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 (message_context->key), message_context->unique_id); #endif #if DEBUG_DHT_ROUTING if ((debug_routes) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_PUT, message_context->hop_count, GNUNET_YES, &my_identity, message_context->key); } #endif if (datacache != NULL) GNUNET_DATACACHE_put (datacache, message_context->key, data_size, (char *) &put_msg[1], put_type, GNUNET_TIME_absolute_ntoh(put_msg->expiration)); else GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': %s request received, but have no datacache!\n", my_short_id, "DHT", "PUT"); } /** * Estimate the diameter of the network based * on how many buckets are currently in use. * Concept here is that the diameter of the network * is roughly the distance a message must travel in * order to reach its intended destination. Since * at each hop we expect to get one bit closer, and * we have one bit per bucket, the number of buckets * in use should be the largest number of hops for * a sucessful message. (of course, this assumes we * know all peers in the network!) * * @return ballpark diameter figure */ static unsigned int estimate_diameter() { return MAX_BUCKETS - lowest_bucket; } /** * To how many peers should we (on average) * forward the request to obtain the desired * target_replication count (on average). * * Always 0, 1 or 2 (don't send, send once, split) */ static unsigned int get_forward_count (unsigned int hop_count, size_t target_replication) { double target_count; unsigned int target_value; unsigned int diameter; /* FIXME: the smaller we think the network is the more lenient we should be for * routing right? The estimation below only works if we think we have reasonably * full routing tables, which for our RR topologies may not be the case! */ diameter = estimate_diameter (); if ((hop_count > (diameter + 1) * 2) && (MINIMUM_PEER_THRESHOLD < estimate_diameter() * bucket_size)) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Hop count too high (est %d, lowest %d), NOT Forwarding request\n", my_short_id, "DHT", estimate_diameter(), lowest_bucket); #endif return 0; } else if (hop_count > MAX_HOPS) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Hop count too high (greater than max)\n", my_short_id, "DHT"); #endif return 0; } target_count = /* target_count is ALWAYS < 1 unless replication is < 1 */ target_replication / (target_replication * (hop_count + 1) + diameter); target_value = 0; #if NONSENSE while (target_value < target_count) target_value++; /* target_value is ALWAYS 1 after this "loop" */ #else target_value = 1; #endif if ((target_count + 1 - target_value) > GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, RAND_MAX) / RAND_MAX) target_value++; return target_value; } /** * 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; } /* * Check whether my identity is closer than any known peers. * * @param target hash code to check closeness to * * Return GNUNET_YES if node location is closest, GNUNET_NO * otherwise. */ int am_closest_peer (const GNUNET_HashCode * target) { int bits; int other_bits; int bucket_num; int count; struct PeerInfo *pos; unsigned int my_distance; bucket_num = find_current_bucket(target); if (bucket_num == GNUNET_SYSERR) /* Same key! */ return GNUNET_YES; bits = 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)) { other_bits = 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, do distance comparison */ { /* FIXME: why not just return GNUNET_YES here? We are certainly close. */ if (distance(&pos->id.hashPubKey, target) < my_distance) return GNUNET_NO; } pos = pos->next; } #if DEBUG_TABLE GNUNET_GE_LOG (coreAPI->ectx, GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER | GNUNET_GE_BULK, "closest peer\n"); printPeerBits (&closest); GNUNET_GE_LOG (coreAPI->ectx, GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER | GNUNET_GE_BULK, "me\n"); printPeerBits (coreAPI->my_identity); GNUNET_GE_LOG (coreAPI->ectx, GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER | GNUNET_GE_BULK, "key\n"); printKeyBits (target); GNUNET_GE_LOG (coreAPI->ectx, GNUNET_GE_WARNING | GNUNET_GE_ADMIN | GNUNET_GE_USER | GNUNET_GE_BULK, "closest peer inverse distance is %u, mine is %u\n", inverse_distance (target, &closest.hashPubKey), inverse_distance (target, &coreAPI->my_identity->hashPubKey)); #endif /* 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 * * @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 distance; unsigned int bc; unsigned int count; struct PeerInfo *pos; #if USE_KADEMLIA const struct PeerInfo *chosen; unsigned long long largest_distance; #else unsigned long long total_distance; unsigned long long selected; #endif #if USE_KADEMLIA largest_distance = 0; chosen = NULL; for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++) { pos = k_buckets[bc].head; while (pos != NULL) { 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; } } pos = pos->next; } } if ((largest_distance > 0) && (chosen != NULL)) { GNUNET_CONTAINER_bloomfilter_add(bloom, &chosen->id.hashPubKey); return chosen; } else { return NULL; } #else /* GNUnet-style */ total_distance = 0; for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++) { pos = k_buckets[bc].head; count = 0; while ((pos != NULL) && (count < bucket_size)) { if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) total_distance += (unsigned long long)inverse_distance (target, &pos->id.hashPubKey); #if DEBUG_DHT > 1 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Total distance is %llu, distance from %s to %s is %u\n", my_short_id, "DHT", total_distance, GNUNET_i2s(&pos->id), GNUNET_h2s(target) , inverse_distance(target, &pos->id.hashPubKey)); #endif pos = pos->next; count++; } } if (total_distance == 0) { return NULL; } selected = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_WEAK, total_distance); for (bc = lowest_bucket; bc < MAX_BUCKETS; bc++) { pos = k_buckets[bc].head; count = 0; while ((pos != NULL) && (count < bucket_size)) { if (GNUNET_NO == GNUNET_CONTAINER_bloomfilter_test (bloom, &pos->id.hashPubKey)) { distance = inverse_distance (target, &pos->id.hashPubKey); if (distance > selected) return pos; selected -= distance; } else { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': peer %s matches bloomfilter.\n", my_short_id, "DHT", GNUNET_i2s(&pos->id)); #endif } pos = pos->next; count++; } } #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': peer %s matches bloomfilter.\n", my_short_id, "DHT", GNUNET_i2s(&pos->id)); #endif return NULL; #endif } /** * Function called to send a request out to another peer. * Called both for locally initiated requests and those * received from other peers. * * @param cls DHT service closure argument * @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 (void *cls, 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; msize = sizeof (struct GNUNET_DHT_P2PRouteMessage) + ntohs(msg->size); 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(); 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); route_message->unique_id = GNUNET_htonll(msg_ctx->unique_id); 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 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 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(sched, &try_core_send, peer); } /** * 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(forward_list.minHeap, 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); } GNUNET_free(source_info); } /** * 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 cls DHT service closure * @param msg_ctx Context of the route request * * @return GNUNET_YES if this response was cached, GNUNET_NO if not */ static int cache_response(void *cls, 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); 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); } GNUNET_SCHEDULER_cancel(sched, source_info->delete_task); GNUNET_free(source_info); current_size = GNUNET_CONTAINER_multihashmap_size(forward_list.hashmap); } 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.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(sched, DHT_FORWARD_TIMEOUT, &remove_forward_entry, source_info); memcpy(&source_info->source, msg_ctx->peer, sizeof(struct GNUNET_PeerIdentity)); 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.value); #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 * * @return the number of peers the message was routed to, * GNUNET_SYSERR on failure */ static int route_message(void *cls, const struct GNUNET_MessageHeader *msg, struct DHT_MessageContext *message_context) { int i; struct PeerInfo *selected; struct PeerInfo *nearest; unsigned int forward_count; #if DEBUG_DHT char *nearest_buf; #endif #if DEBUG_DHT_ROUTING int ret; #endif message_context->closest = am_closest_peer(message_context->key); forward_count = get_forward_count(message_context->hop_count, message_context->replication); nearest = find_closest_peer(message_context->key); if (message_context->bloom == NULL) message_context->bloom = GNUNET_CONTAINER_bloomfilter_init (NULL, DHT_BLOOM_SIZE, DHT_BLOOM_K); GNUNET_CONTAINER_bloomfilter_add (message_context->bloom, &my_identity.hashPubKey); if ((stop_on_closest == GNUNET_YES) && (message_context->closest == GNUNET_YES) && (ntohs(msg->type) == GNUNET_MESSAGE_TYPE_DHT_PUT)) forward_count = 0; #if DEBUG_DHT_ROUTING if (forward_count == 0) ret = GNUNET_SYSERR; else ret = GNUNET_NO; if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE, message_context->hop_count, ret, &my_identity, message_context->key, message_context->peer, NULL); } #endif switch (ntohs(msg->type)) { case GNUNET_MESSAGE_TYPE_DHT_GET: /* Add to hashmap of requests seen, search for data (always) */ cache_response (cls, message_context); if ((handle_dht_get (cls, msg, message_context) > 0) && (stop_on_found == GNUNET_YES)) forward_count = 0; break; case GNUNET_MESSAGE_TYPE_DHT_PUT: /* Check if closest, if so insert data. FIXME: thresholding to reduce complexity?*/ if (message_context->closest == GNUNET_YES) { #if DEBUG_DHT_ROUTING if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE, message_context->hop_count, GNUNET_YES, &my_identity, message_context->key, message_context->peer, NULL); } #endif handle_dht_put (cls, msg, message_context); } #if DEBUG_DHT_ROUTING if (message_context->hop_count == 0) /* Locally initiated request */ { if ((debug_routes) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_PUT, message_context->hop_count, GNUNET_NO, &my_identity, message_context->key); } } #endif break; case GNUNET_MESSAGE_TYPE_DHT_FIND_PEER: /* Check if closest and not started by us, check options, add to requests seen */ if (((message_context->hop_count > 0) && (0 != memcmp(message_context->peer, &my_identity, sizeof(struct GNUNET_PeerIdentity)))) || (message_context->client != NULL)) { cache_response (cls, message_context); if ((message_context->closest == GNUNET_YES) || (message_context->msg_options == GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE)) handle_dht_find_peer (cls, msg, message_context); } #if DEBUG_DHT_ROUTING if (message_context->hop_count == 0) /* Locally initiated request */ { if ((debug_routes) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_dhtkey(NULL, message_context->key); dhtlog_handle->insert_query (NULL, message_context->unique_id, DHTLOG_FIND_PEER, message_context->hop_count, GNUNET_NO, &my_identity, message_context->key); } } #endif break; default: GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "`%s': Message type (%d) not handled\n", "DHT", ntohs(msg->type)); } for (i = 0; i < forward_count; i++) { selected = select_peer(message_context->key, message_context->bloom); /* FIXME: either log to sql or log to stats or both when selected is NULL at this point! */ if (selected != NULL) { GNUNET_CONTAINER_bloomfilter_add(message_context->bloom, &selected->id.hashPubKey); #if DEBUG_DHT_ROUTING > 1 nearest_buf = GNUNET_strdup(GNUNET_i2s(&nearest->id)); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Forwarding request key %s uid %llu to peer %s (closest %s, bits %d, distance %u)\n", my_short_id, "DHT", GNUNET_h2s (message_context->key), message_context->unique_id, GNUNET_i2s(&selected->id), nearest_buf, matching_bits(&nearest->id.hashPubKey, message_context->key), distance(&nearest->id.hashPubKey, message_context->key)); GNUNET_free(nearest_buf); #endif /* FIXME: statistics */ if ((debug_routes_extended) && (dhtlog_handle != NULL)) { dhtlog_handle->insert_route (NULL, message_context->unique_id, DHTLOG_ROUTE, message_context->hop_count, GNUNET_NO, &my_identity, message_context->key, message_context->peer, &selected->id); } forward_message(cls, msg, selected, message_context); } else { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': No peers selected for forwarding.\n", my_short_id, "DHT"); #endif } } #if DEBUG_DHT_ROUTING > 1 if (forward_count == 0) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': NOT Forwarding request key %s uid %llu to any peers\n", my_short_id, "DHT", GNUNET_h2s (message_context->key), message_context->unique_id); } #endif if (message_context->bloom != NULL) GNUNET_CONTAINER_bloomfilter_free(message_context->bloom); return forward_count; } /** * Find a client if it exists, add it otherwise. * * @param client the server handle to the client * * @return the client if found, a new client otherwise */ static struct ClientList * find_active_client (struct GNUNET_SERVER_Client *client) { struct ClientList *pos = client_list; struct ClientList *ret; while (pos != NULL) { if (pos->client_handle == client) return pos; pos = pos->next; } ret = GNUNET_malloc (sizeof (struct ClientList)); ret->client_handle = client; ret->next = client_list; client_list = ret; return ret; } /** * Task to send a find peer message for our own peer identifier * so that we can find the closest peers in the network to ourselves * and attempt to connect to them. * * @param cls closure for this task * @param tc the context under which the task is running */ static void send_find_peer_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_MessageHeader *find_peer_msg; struct DHT_MessageContext message_context; int ret; if (tc->reason == GNUNET_SCHEDULER_REASON_SHUTDOWN) return; find_peer_msg = GNUNET_malloc(sizeof(struct GNUNET_MessageHeader)); find_peer_msg->size = htons(sizeof(struct GNUNET_MessageHeader)); find_peer_msg->type = htons(GNUNET_MESSAGE_TYPE_DHT_FIND_PEER); memset(&message_context, 0, sizeof(struct DHT_MessageContext)); message_context.key = &my_identity.hashPubKey; message_context.unique_id = GNUNET_ntohll (GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_STRONG, (uint64_t)-1)); message_context.replication = ntohl (DHT_DEFAULT_FIND_PEER_REPLICATION); message_context.msg_options = ntohl (DHT_DEFAULT_FIND_PEER_OPTIONS); message_context.network_size = estimate_diameter(); message_context.peer = &my_identity; ret = route_message(NULL, find_peer_msg, &message_context); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Sent `%s' request to %d peers\n", my_short_id, "DHT", "FIND PEER", ret); GNUNET_SCHEDULER_add_delayed (sched, DHT_DEFAULT_FIND_PEER_INTERVAL, &send_find_peer_message, NULL); } /** * Handler for any generic DHT messages, calls the appropriate handler * depending on message type, sends confirmation if responses aren't otherwise * expected. * * @param cls closure for the service * @param client the client we received this message from * @param message the actual message received */ static void handle_dht_local_route_request (void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { const struct GNUNET_DHT_RouteMessage *dht_msg = (const struct GNUNET_DHT_RouteMessage *) message; const struct GNUNET_MessageHeader *enc_msg; struct DHT_MessageContext message_context; size_t enc_type; enc_msg = (const struct GNUNET_MessageHeader *) &dht_msg[1]; enc_type = ntohs (enc_msg->type); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request from client, message type %d, key %s, uid %llu\n", my_short_id, "DHT", "GENERIC", enc_type, GNUNET_h2s (&dht_msg->key), GNUNET_ntohll (dht_msg->unique_id)); #endif #if DEBUG_DHT_ROUTING if (dhtlog_handle != NULL) dhtlog_handle->insert_dhtkey (NULL, &dht_msg->key); #endif memset(&message_context, 0, sizeof(struct DHT_MessageContext)); message_context.client = find_active_client (client); message_context.key = &dht_msg->key; message_context.unique_id = GNUNET_ntohll (dht_msg->unique_id); message_context.replication = ntohl (dht_msg->desired_replication_level); message_context.msg_options = ntohl (dht_msg->options); message_context.network_size = estimate_diameter(); message_context.peer = &my_identity; route_message(cls, enc_msg, &message_context); GNUNET_SERVER_receive_done (client, GNUNET_OK); } /** * Handler for any generic DHT stop messages, calls the appropriate handler * depending on message type (if processed locally) * * @param cls closure for the service * @param client the client we received this message from * @param message the actual message received * */ static void handle_dht_local_route_stop(void *cls, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { const struct GNUNET_DHT_StopMessage *dht_stop_msg = (const struct GNUNET_DHT_StopMessage *) message; struct DHTQueryRecord *record; struct DHTRouteSource *pos; uint64_t uid; #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received `%s' request from client, uid %llu\n", my_short_id, "DHT", "GENERIC STOP", GNUNET_ntohll (dht_stop_msg->unique_id)); #endif uid = GNUNET_ntohll(dht_stop_msg->unique_id); record = GNUNET_CONTAINER_multihashmap_get(forward_list.hashmap, &dht_stop_msg->key); if (record != NULL) { pos = record->head; while (pos != NULL) { if ((pos->client != NULL) && (pos->client->client_handle == client)) { GNUNET_SCHEDULER_cancel(sched, pos->delete_task); GNUNET_SCHEDULER_add_now(sched, &remove_forward_entry, pos); } pos = pos->next; } } GNUNET_SERVER_receive_done (client, GNUNET_OK); } /** * Core handler for p2p route requests. */ static int handle_dht_p2p_route_request (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message, struct GNUNET_TIME_Relative latency, uint32_t distance) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received P2P request from peer %s\n", my_short_id, "DHT", GNUNET_i2s(peer)); #endif struct GNUNET_DHT_P2PRouteMessage *incoming = (struct GNUNET_DHT_P2PRouteMessage *)message; struct GNUNET_MessageHeader *enc_msg = (struct GNUNET_MessageHeader *)&incoming[1]; struct DHT_MessageContext *message_context; if (ntohs(enc_msg->size) > GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break_op(0); return GNUNET_YES; } //memset(&message_context, 0, sizeof(struct DHT_MessageContext)); message_context = GNUNET_malloc(sizeof (struct DHT_MessageContext)); message_context->bloom = GNUNET_CONTAINER_bloomfilter_init(incoming->bloomfilter, DHT_BLOOM_SIZE, DHT_BLOOM_K); GNUNET_assert(message_context->bloom != NULL); message_context->hop_count = ntohl(incoming->hop_count); message_context->key = &incoming->key; message_context->replication = ntohl(incoming->desired_replication_level); message_context->unique_id = GNUNET_ntohll(incoming->unique_id); message_context->msg_options = ntohl(incoming->options); message_context->network_size = ntohl(incoming->network_size); message_context->peer = peer; route_message(cls, enc_msg, message_context); GNUNET_free(message_context); return GNUNET_YES; } /** * Core handler for p2p route results. */ static int handle_dht_p2p_route_result (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_MessageHeader *message, struct GNUNET_TIME_Relative latency, uint32_t distance) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "`%s:%s': Received request from peer %s\n", my_short_id, "DHT", GNUNET_i2s(peer)); #endif struct GNUNET_DHT_P2PRouteResultMessage *incoming = (struct GNUNET_DHT_P2PRouteResultMessage *)message; struct GNUNET_MessageHeader *enc_msg = (struct GNUNET_MessageHeader *)&incoming[1]; struct DHT_MessageContext message_context; if (ntohs(enc_msg->size) > GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break_op(0); return GNUNET_YES; } memset(&message_context, 0, sizeof(struct DHT_MessageContext)); message_context.bloom = GNUNET_CONTAINER_bloomfilter_init(incoming->bloomfilter, DHT_BLOOM_SIZE, DHT_BLOOM_K); GNUNET_assert(message_context.bloom != NULL); message_context.key = &incoming->key; message_context.unique_id = GNUNET_ntohll(incoming->unique_id); message_context.msg_options = ntohl(incoming->options); message_context.hop_count = ntohl(incoming->hop_count); message_context.peer = peer; route_result_message(cls, enc_msg, &message_context); return GNUNET_YES; } /** * 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 (transport_handle != NULL) { GNUNET_free_non_null(my_hello); GNUNET_TRANSPORT_get_hello_cancel(transport_handle, &process_hello, NULL); GNUNET_TRANSPORT_disconnect(transport_handle); } 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 (coreAPI != NULL) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Disconnecting core!\n", my_short_id, "DHT"); #endif GNUNET_CORE_disconnect (coreAPI); } 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); } if (dhtlog_handle != NULL) GNUNET_DHTLOG_disconnect(dhtlog_handle); GNUNET_free_non_null(my_short_id); } /** * To be called on core init/fail. * * @param cls service closure * @param server handle to the server for this service * @param identity the public identity of this peer * @param publicKey the public key of this peer */ void core_init (void *cls, struct GNUNET_CORE_Handle *server, const struct GNUNET_PeerIdentity *identity, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey) { if (server == NULL) { #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s: Connection to core FAILED!\n", "dht", GNUNET_i2s (identity)); #endif GNUNET_SCHEDULER_cancel (sched, cleanup_task); GNUNET_SCHEDULER_add_now (sched, &shutdown_task, NULL); return; } #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s: Core connection initialized, I am peer: %s\n", "dht", GNUNET_i2s (identity)); #endif /* Copy our identity so we can use it */ memcpy (&my_identity, identity, sizeof (struct GNUNET_PeerIdentity)); my_short_id = GNUNET_strdup(GNUNET_i2s(&my_identity)); /* Set the server to local variable */ coreAPI = server; if (dhtlog_handle != NULL) dhtlog_handle->insert_node (NULL, &my_identity); } static struct GNUNET_SERVER_MessageHandler plugin_handlers[] = { {&handle_dht_local_route_request, NULL, GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE, 0}, {&handle_dht_local_route_stop, NULL, GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_STOP, 0}, {NULL, NULL, 0, 0} }; static struct GNUNET_CORE_MessageHandler core_handlers[] = { {&handle_dht_p2p_route_request, GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE, 0}, {&handle_dht_p2p_route_result, GNUNET_MESSAGE_TYPE_DHT_P2P_ROUTE_RESULT, 0}, {NULL, 0, 0} }; /** * Method called whenever a peer connects. * * @param cls closure * @param peer peer identity this notification is about * @param latency reported latency of the connection with peer * @param distance reported distance (DV) to peer */ void handle_core_connect (void *cls, const struct GNUNET_PeerIdentity * peer, struct GNUNET_TIME_Relative latency, uint32_t distance) { struct PeerInfo *ret; #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Receives core connect message for peer %s distance %d!\n", my_short_id, "dht", GNUNET_i2s(peer), distance); #endif if (datacache != NULL) GNUNET_DATACACHE_put(datacache, &peer->hashPubKey, sizeof(struct GNUNET_PeerIdentity), (const char *)peer, 0, GNUNET_TIME_absolute_get_forever()); ret = try_add_peer(peer, find_current_bucket(&peer->hashPubKey), latency, distance); if (ret != NULL) GNUNET_CONTAINER_multihashmap_put(all_known_peers, &peer->hashPubKey, ret, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s:%s Adding peer to routing list: %s\n", my_short_id, "DHT", ret == NULL ? "NOT ADDED" : "PEER ADDED"); #endif } /** * Method called whenever a peer disconnects. * * @param cls closure * @param peer peer identity this notification is about */ void handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity * peer) { struct PeerInfo *to_remove; int current_bucket; GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "%s:%s: Received peer disconnect message for peer `%s' from %s\n", my_short_id, "DHT", GNUNET_i2s(peer), "CORE"); GNUNET_assert(GNUNET_CONTAINER_multihashmap_contains(all_known_peers, &peer->hashPubKey)); to_remove = GNUNET_CONTAINER_multihashmap_get(all_known_peers, &peer->hashPubKey); GNUNET_assert(0 == memcmp(peer, &to_remove->id, sizeof(struct GNUNET_PeerIdentity))); current_bucket = find_current_bucket(&to_remove->id.hashPubKey); delete_peer(to_remove, current_bucket); } /** * Process dht requests. * * @param cls closure * @param scheduler scheduler to use * @param server the initialized server * @param c configuration to use */ static void run (void *cls, struct GNUNET_SCHEDULER_Handle *scheduler, struct GNUNET_SERVER_Handle *server, const struct GNUNET_CONFIGURATION_Handle *c) { sched = scheduler; cfg = c; datacache = GNUNET_DATACACHE_create (sched, cfg, "dhtcache"); GNUNET_SERVER_add_handlers (server, plugin_handlers); coreAPI = GNUNET_CORE_connect (sched, /* Main scheduler */ cfg, /* Main configuration */ GNUNET_TIME_UNIT_FOREVER_REL, NULL, /* Closure passed to DHT functionas around? */ &core_init, /* Call core_init once connected */ &handle_core_connect, /* Handle connects */ &handle_core_disconnect, /* FIXME: 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(sched, cfg, NULL, NULL, NULL, NULL, NULL); if (transport_handle != NULL) GNUNET_TRANSPORT_get_hello (transport_handle, &process_hello, NULL); else GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Failed to connect to transport service!\n"); lowest_bucket = MAX_BUCKETS - 1; forward_list.hashmap = GNUNET_CONTAINER_multihashmap_create(MAX_OUTSTANDING_FORWARDS / 10); forward_list.minHeap = GNUNET_CONTAINER_heap_create(GNUNET_CONTAINER_HEAP_ORDER_MIN); all_known_peers = GNUNET_CONTAINER_multihashmap_create(MAX_BUCKETS / 8); GNUNET_assert(all_known_peers != NULL); if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht_testing", "mysql_logging")) { debug_routes = GNUNET_YES; } if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht", "stop_on_closest")) { stop_on_closest = GNUNET_YES; } if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht", "stop_found")) { stop_on_found = GNUNET_YES; } if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg, "dht_testing", "mysql_logging_extended")) { debug_routes = GNUNET_YES; debug_routes_extended = GNUNET_YES; } if (GNUNET_YES == debug_routes) { dhtlog_handle = GNUNET_DHTLOG_connect(cfg); if (dhtlog_handle == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Could not connect to mysql logging server, logging will not happen!"); } } #if DO_FIND_PEER GNUNET_SCHEDULER_add_delayed (sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 30), &send_find_peer_message, NULL); #endif /* Scheduled the task to clean up when shutdown is called */ cleanup_task = GNUNET_SCHEDULER_add_delayed (sched, 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) { return (GNUNET_OK == GNUNET_SERVICE_run (argc, argv, "dht", GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1; }