/* This file is part of GNUnet. Copyright (C) 2013, 2016 GNUnet e.V. GNUnet is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, 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 Affero General Public License for more details. */ /** * @file dv/gnunet-service-dv.c * @brief the distance vector service, primarily handles gossip of nearby * peers and sending/receiving DV messages from core and decapsulating * them * * @author Christian Grothoff * @author Nathan Evans */ #include "platform.h" #include "gnunet_util_lib.h" #include "gnunet_protocols.h" #include "gnunet_core_service.h" #include "gnunet_hello_lib.h" #include "gnunet_peerinfo_service.h" #include "gnunet_statistics_service.h" #include "gnunet_set_service.h" #include "gnunet_ats_service.h" #include "dv.h" #include /** * How often do we establish the consensu? */ #define GNUNET_DV_CONSENSUS_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 5) /** * Maximum number of messages we queue per peer. */ #define MAX_QUEUE_SIZE 16 /** * Maximum number of messages we queue towards the clients/plugin. */ #define MAX_QUEUE_SIZE_PLUGIN 1024 /** * The default fisheye depth, from how many hops away will * we keep peers? */ #define DEFAULT_FISHEYE_DEPTH 3 /** * How many hops is a direct neighbor away? */ #define DIRECT_NEIGHBOR_COST 1 GNUNET_NETWORK_STRUCT_BEGIN /** * Information about a peer DV can route to. These entries are what * we use as the binary format to establish consensus to create our * routing table and as the address format in the HELLOs. */ struct Target { /** * Identity of the peer we can reach. */ struct GNUNET_PeerIdentity peer; /** * How many hops (1-3) is this peer away? in network byte order */ uint32_t distance GNUNET_PACKED; }; /** * Message exchanged between DV services (via core), requesting a * message to be routed. */ struct RouteMessage { /** * Type: #GNUNET_MESSAGE_TYPE_DV_ROUTE */ struct GNUNET_MessageHeader header; /** * Expected (remaining) distance. Must be always smaller than * #DEFAULT_FISHEYE_DEPTH, should be zero at the target. Must * be decremented by one at each hop. Peers must not forward * these messages further once the counter has reached zero. */ uint32_t distance GNUNET_PACKED; /** * The (actual) target of the message (this peer, if distance is zero). */ struct GNUNET_PeerIdentity target; /** * The (actual) sender of the message. */ struct GNUNET_PeerIdentity sender; }; GNUNET_NETWORK_STRUCT_END /** * Information about a direct neighbor (core-level, excluding * DV-links, only DV-enabled peers). */ struct DirectNeighbor { /** * Identity of the peer. */ struct GNUNET_PeerIdentity peer; /** * Session ID we use whenever we create a set union with * this neighbor; constructed from the XOR of our peer * IDs and then salted with "DV-SALT" to avoid conflicts * with other applications. */ struct GNUNET_HashCode real_session_id; /** * Transmit handle to core service. */ struct GNUNET_MQ_Handle *mq; /** * Routing table of the neighbor, NULL if not yet established. * Keys are peer identities, values are 'struct Target' entries. * Note that the distances in the targets are from the point-of-view * of the peer, not from us! */ struct GNUNET_CONTAINER_MultiPeerMap *neighbor_table; /** * Updated routing table of the neighbor, under construction, * NULL if we are not currently building it. * Keys are peer identities, values are 'struct Target' entries. * Note that the distances in the targets are from the point-of-view * of the other peer, not from us! */ struct GNUNET_CONTAINER_MultiPeerMap *neighbor_table_consensus; /** * Our current (exposed) routing table as a set. */ struct GNUNET_SET_Handle *my_set; /** * Handle for our current active set union operation. */ struct GNUNET_SET_OperationHandle *set_op; /** * Handle used if we are listening for this peer, waiting for the * other peer to initiate construction of the set union. NULL if * we ar the initiating peer. */ struct GNUNET_SET_ListenHandle *listen_handle; /** * ID of the task we use to (periodically) update our consensus * with this peer. Used if we are the initiating peer. */ struct GNUNET_SCHEDULER_Task *initiate_task; /** * At what offset are we, with respect to inserting our own routes * into the consensus? */ unsigned int consensus_insertion_offset; /** * At what distance are we, with respect to inserting our own routes * into the consensus? */ unsigned int consensus_insertion_distance; /** * Elements in consensus */ unsigned int consensus_elements; /** * Direct one hop route */ struct Route *direct_route; /** * Flag set within 'check_target_removed' to trigger full global route refresh. */ int target_removed; /** * Our distance to this peer, 0 for unknown. */ uint32_t distance; /** * The network this peer is in */ enum GNUNET_ATS_Network_Type network; /** * Is this neighbor connected at the core level? */ int connected; }; /** * A route includes information about the next hop, * the target, and the ultimate distance to the * target. */ struct Route { /** * Which peer do we need to forward the message to? */ struct DirectNeighbor *next_hop; /** * What would be the target, and how far is it away? */ struct Target target; /** * Offset of this target in the respective consensus set. */ unsigned int set_offset; }; /** * Set of targets we bring to a consensus; all targets in a set have a * distance equal to the sets distance (which is implied by the array * index of the set). */ struct ConsensusSet { /** * Array of targets in the set, may include NULL entries if a * neighbor has disconnected; the targets are allocated with the * respective container (all_routes), not here. */ struct Route **targets; /** * Size of the @e targets array. */ unsigned int array_length; }; /** * Peermap of all of our neighbors; processing these usually requires * first checking to see if the peer is core-connected and if the * distance is 1, in which case they are direct neighbors. */ static struct GNUNET_CONTAINER_MultiPeerMap *direct_neighbors; /** * Hashmap with all routes that we currently support; contains * routing information for all peers from distance 2 * up to distance #DEFAULT_FISHEYE_DEPTH. */ static struct GNUNET_CONTAINER_MultiPeerMap *all_routes; /** * Array of consensus sets we expose to the outside world. Sets * are structured by the distance to the target. */ static struct ConsensusSet consensi[DEFAULT_FISHEYE_DEPTH]; /** * Handle to the core service api. */ static struct GNUNET_CORE_Handle *core_api; /** * The identity of our peer. */ static struct GNUNET_PeerIdentity my_identity; /** * The configuration for this service. */ static const struct GNUNET_CONFIGURATION_Handle *cfg; /** * The client, the DV plugin connected to us (or an event monitor). * Hopefully this client will never change, although if the plugin * dies and returns for some reason it may happen. */ static struct GNUNET_NotificationContext *nc; /** * Handle for the statistics service. */ static struct GNUNET_STATISTICS_Handle *stats; /** * Handle to ATS service. */ static struct GNUNET_ATS_PerformanceHandle *ats; /** * Task scheduled to refresh routes based on direct neighbours. */ static struct GNUNET_SCHEDULER_Task *rr_task; /** * #GNUNET_YES if we are shutting down. */ static int in_shutdown; /** * Start creating a new DV set union by initiating the connection. * * @param cls the 'struct DirectNeighbor' of the peer we're building * a routing consensus with */ static void initiate_set_union (void *cls); /** * Start creating a new DV set union construction, our neighbour has * asked for it (callback for listening peer). * * @param cls the 'struct DirectNeighbor' of the peer we're building * a routing consensus with * @param other_peer the other peer * @param context_msg message with application specific information from * the other peer * @param request request from the other peer, use GNUNET_SET_accept * to accept it, otherwise the request will be refused * Note that we don't use a return value here, as it is also * necessary to specify the set we want to do the operation with, * whith sometimes can be derived from the context message. * Also necessary to specify the timeout. */ static void listen_set_union (void *cls, const struct GNUNET_PeerIdentity *other_peer, const struct GNUNET_MessageHeader *context_msg, struct GNUNET_SET_Request *request); /** * Forward a message from another peer to the plugin. * * @param message the message to send to the plugin * @param origin the original sender of the message * @param distance distance to the original sender of the message */ static void send_data_to_plugin (const struct GNUNET_MessageHeader *message, const struct GNUNET_PeerIdentity *origin, uint32_t distance) { struct GNUNET_DV_ReceivedMessage *received_msg; size_t size; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Delivering message from peer `%s' at distance %u\n", GNUNET_i2s (origin), (unsigned int) distance); size = sizeof (struct GNUNET_DV_ReceivedMessage) + ntohs (message->size); if (size >= GNUNET_MAX_MESSAGE_SIZE) { GNUNET_break (0); /* too big */ return; } received_msg = GNUNET_malloc (size); received_msg->header.size = htons (size); received_msg->header.type = htons (GNUNET_MESSAGE_TYPE_DV_RECV); received_msg->distance = htonl (distance); received_msg->sender = *origin; GNUNET_memcpy (&received_msg[1], message, ntohs (message->size)); GNUNET_notification_context_broadcast (nc, &received_msg->header, GNUNET_YES); GNUNET_free (received_msg); } /** * Forward a control message to the plugin. * * @param message the message to send to the plugin */ static void send_control_to_plugin (const struct GNUNET_MessageHeader *message) { GNUNET_notification_context_broadcast (nc, message, GNUNET_NO); } /** * Send a DISTANCE_CHANGED message to the plugin. * * @param peer peer with a changed distance * @param distance new distance to the peer * @param network network used by the neighbor */ static void send_distance_change_to_plugin (const struct GNUNET_PeerIdentity *peer, uint32_t distance, enum GNUNET_ATS_Network_Type network) { struct GNUNET_DV_DistanceUpdateMessage du_msg; GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Delivering DISTANCE_CHANGED for message about peer `%s'\n", GNUNET_i2s (peer)); du_msg.header.size = htons (sizeof (du_msg)); du_msg.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISTANCE_CHANGED); du_msg.distance = htonl (distance); du_msg.peer = *peer; du_msg.network = htonl ((uint32_t) network); send_control_to_plugin (&du_msg.header); } /** * Give a CONNECT message to the plugin. * * @param target peer that connected * @param distance distance to the target * @param network the network the next hop is located in */ static void send_connect_to_plugin (const struct GNUNET_PeerIdentity *target, uint32_t distance, enum GNUNET_ATS_Network_Type network) { struct GNUNET_DV_ConnectMessage cm; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Delivering CONNECT about peer %s with distance %u\n", GNUNET_i2s (target), distance); cm.header.size = htons (sizeof (cm)); cm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_CONNECT); cm.distance = htonl (distance); cm.network = htonl ((uint32_t) network); cm.peer = *target; send_control_to_plugin (&cm.header); } /** * Give a DISCONNECT message to the plugin. * * @param target peer that disconnected */ static void send_disconnect_to_plugin (const struct GNUNET_PeerIdentity *target) { struct GNUNET_DV_DisconnectMessage dm; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Delivering DISCONNECT about peer `%s'\n", GNUNET_i2s (target)); dm.header.size = htons (sizeof (dm)); dm.header.type = htons (GNUNET_MESSAGE_TYPE_DV_DISCONNECT); dm.reserved = htonl (0); dm.peer = *target; send_control_to_plugin (&dm.header); } /** * Forward the given payload to the given target. * * @param target where to send the message * @param distance distance to the @a sender * @param sender original sender of the message * @param actual_target ultimate recipient for the message * @param payload payload of the message */ static void forward_payload (struct DirectNeighbor *target, uint32_t distance, const struct GNUNET_PeerIdentity *sender, const struct GNUNET_PeerIdentity *actual_target, const struct GNUNET_MessageHeader *payload) { struct GNUNET_MQ_Envelope *env; struct RouteMessage *rm; if ( (GNUNET_MQ_get_length (target->mq) >= MAX_QUEUE_SIZE) && (0 != memcmp (sender, &my_identity, sizeof (struct GNUNET_PeerIdentity))) ) { /* not _our_ client and queue is full, drop */ GNUNET_STATISTICS_update (stats, "# messages dropped", 1, GNUNET_NO); return; } if (sizeof (struct RouteMessage) + ntohs (payload->size) >= GNUNET_MAX_MESSAGE_SIZE) { GNUNET_break (0); return; } env = GNUNET_MQ_msg_nested_mh (rm, GNUNET_MESSAGE_TYPE_DV_ROUTE, payload); rm->distance = htonl (distance); rm->target = *actual_target; rm->sender = *sender; GNUNET_MQ_send (target->mq, env); } /** * Find a free slot for storing a 'route' in the 'consensi' * set at the given distance. * * @param distance distance to use for the set slot */ static unsigned int get_consensus_slot (uint32_t distance) { struct ConsensusSet *cs; unsigned int i; GNUNET_assert (distance < DEFAULT_FISHEYE_DEPTH); cs = &consensi[distance]; i = 0; while ( (i < cs->array_length) && (NULL != cs->targets[i]) ) i++; if (i == cs->array_length) { GNUNET_array_grow (cs->targets, cs->array_length, cs->array_length * 2 + 2); } return i; } /** * Allocate a slot in the consensus set for a route. * * @param route route to initialize * @param distance which consensus set to use */ static void allocate_route (struct Route *route, uint32_t distance) { unsigned int i; if (distance >= DEFAULT_FISHEYE_DEPTH) { route->target.distance = htonl (distance); route->set_offset = UINT_MAX; /* invalid slot */ return; } i = get_consensus_slot (distance); route->set_offset = i; consensi[distance].targets[i] = route; route->target.distance = htonl (distance); } /** * Release a slot in the consensus set for a route. * * @param route route to release the slot from */ static void release_route (struct Route *route) { if (UINT_MAX == route->set_offset) return; GNUNET_assert (ntohl (route->target.distance) < DEFAULT_FISHEYE_DEPTH); consensi[ntohl (route->target.distance)].targets[route->set_offset] = NULL; route->set_offset = UINT_MAX; /* indicate invalid slot */ } /** * Move a route from one consensus set to another. * * @param route route to move * @param new_distance new distance for the route (destination set) */ static void move_route (struct Route *route, uint32_t new_distance) { release_route (route); allocate_route (route, new_distance); } /** * Initialize this neighbors 'my_set' and when done give * it to the pending set operation for execution. * * Add a single element to the set per call: * * If we reached the last element of a consensus element: increase distance * * * @param cls the neighbor for which we are building the set */ static void build_set (void *cls) { struct DirectNeighbor *neighbor = cls; struct GNUNET_SET_Element element; struct Target *target; struct Route *route; target = NULL; /* skip over NULL entries */ while ( (DEFAULT_FISHEYE_DEPTH > neighbor->consensus_insertion_distance) && (consensi[neighbor->consensus_insertion_distance].array_length > neighbor->consensus_insertion_offset) && (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) ) neighbor->consensus_insertion_offset++; while ( (DEFAULT_FISHEYE_DEPTH > neighbor->consensus_insertion_distance) && (consensi[neighbor->consensus_insertion_distance].array_length == neighbor->consensus_insertion_offset) ) { /* If we reached the last element of a consensus array element: increase distance and start with next array */ neighbor->consensus_insertion_offset = 0; neighbor->consensus_insertion_distance++; /* skip over NULL entries */ while ( (DEFAULT_FISHEYE_DEPTH > neighbor->consensus_insertion_distance) && (consensi[neighbor->consensus_insertion_distance].array_length > neighbor->consensus_insertion_offset) && (NULL == consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]) ) neighbor->consensus_insertion_offset++; } if (DEFAULT_FISHEYE_DEPTH == neighbor->consensus_insertion_distance) { /* we have added all elements to the set, run the operation */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Finished building my SET for peer `%s' with %u elements, committing\n", GNUNET_i2s (&neighbor->peer), neighbor->consensus_elements); GNUNET_SET_commit (neighbor->set_op, neighbor->my_set); GNUNET_SET_destroy (neighbor->my_set); neighbor->my_set = NULL; return; } route = consensi[neighbor->consensus_insertion_distance].targets[neighbor->consensus_insertion_offset]; GNUNET_assert (NULL != route); target = &route->target; GNUNET_assert (ntohl (target->distance) < DEFAULT_FISHEYE_DEPTH); element.size = sizeof (struct Target); element.element_type = htons (0); element.data = target; /* Find next non-NULL entry */ neighbor->consensus_insertion_offset++; if ( (0 != memcmp (&target->peer, &my_identity, sizeof (my_identity))) && (0 != memcmp (&target->peer, &neighbor->peer, sizeof (struct GNUNET_PeerIdentity))) ) { /* Add target if it is not the neighbor or this peer */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Adding peer `%s' with distance %u to SET\n", GNUNET_i2s (&target->peer), ntohl (target->distance) + 1); GNUNET_SET_add_element (neighbor->my_set, &element, &build_set, neighbor); neighbor->consensus_elements++; } else build_set (neighbor); } /** * A peer is now connected to us at distance 1. Initiate DV exchange. * * @param neighbor entry for the neighbor at distance 1 */ static void handle_direct_connect (struct DirectNeighbor *neighbor) { struct Route *route; struct GNUNET_HashCode h1; struct GNUNET_HashCode h2; struct GNUNET_HashCode session_id; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Direct connection to %s established, routing table exchange begins.\n", GNUNET_i2s (&neighbor->peer)); GNUNET_STATISTICS_update (stats, "# peers connected (1-hop)", 1, GNUNET_NO); route = GNUNET_CONTAINER_multipeermap_get (all_routes, &neighbor->peer); if (NULL != route) { GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (all_routes, &neighbor->peer, route)); send_disconnect_to_plugin (&neighbor->peer); release_route (route); GNUNET_free (route); } neighbor->direct_route = GNUNET_new (struct Route); neighbor->direct_route->next_hop = neighbor; neighbor->direct_route->target.peer = neighbor->peer; allocate_route (neighbor->direct_route, DIRECT_NEIGHBOR_COST); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Adding direct route to %s\n", GNUNET_i2s (&neighbor->direct_route->target.peer)); /* construct session ID seed as XOR of both peer's identities */ GNUNET_CRYPTO_hash (&my_identity, sizeof (my_identity), &h1); GNUNET_CRYPTO_hash (&neighbor->peer, sizeof (struct GNUNET_PeerIdentity), &h2); GNUNET_CRYPTO_hash_xor (&h1, &h2, &session_id); /* make sure session ID is unique across applications by salting it with 'DV' */ GNUNET_CRYPTO_hkdf (&neighbor->real_session_id, sizeof (struct GNUNET_HashCode), GCRY_MD_SHA512, GCRY_MD_SHA256, "DV-SALT", 2, &session_id, sizeof (session_id), NULL, 0); if (0 < memcmp (&neighbor->peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))) { if (NULL != neighbor->listen_handle) { GNUNET_break (0); } else neighbor->initiate_task = GNUNET_SCHEDULER_add_now (&initiate_set_union, neighbor); } else { if (NULL != neighbor->listen_handle) { GNUNET_break (0); } else { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting SET listen operation with peer `%s'\n", GNUNET_i2s (&neighbor->peer)); neighbor->listen_handle = GNUNET_SET_listen (cfg, GNUNET_SET_OPERATION_UNION, &neighbor->real_session_id, &listen_set_union, neighbor); } } } /** * Method called whenever a peer connects. * * @param cls closure * @param peer peer identity this notification is about * @param mq message queue for sending data to @a peer * @return our `struct DirectNeighbour` for this peer */ static void * handle_core_connect (void *cls, const struct GNUNET_PeerIdentity *peer, struct GNUNET_MQ_Handle *mq) { struct DirectNeighbor *neighbor; /* Check for connect to self message */ if (0 == memcmp (&my_identity, peer, sizeof (struct GNUNET_PeerIdentity))) return NULL; /* check if entry exists */ neighbor = GNUNET_CONTAINER_multipeermap_get (direct_neighbors, peer); if (NULL != neighbor) { GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != neighbor->network); GNUNET_break (GNUNET_YES != neighbor->connected); neighbor->connected = GNUNET_YES; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Core connected to %s (distance %u)\n", GNUNET_i2s (peer), (unsigned int) neighbor->distance); if (DIRECT_NEIGHBOR_COST != neighbor->distance) return NULL; handle_direct_connect (neighbor); return NULL; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Core connected to %s (distance unknown)\n", GNUNET_i2s (peer)); neighbor = GNUNET_new (struct DirectNeighbor); neighbor->peer = *peer; GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_put (direct_neighbors, &neighbor->peer, neighbor, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); neighbor->connected = GNUNET_YES; neighbor->distance = 0; /* unknown */ neighbor->network = GNUNET_ATS_NET_UNSPECIFIED; return neighbor; } /** * Called for each 'target' in a neighbor table to free the associated memory. * * @param cls NULL * @param key key of the value * @param value value to free * @return #GNUNET_OK to continue to iterate */ static int free_targets (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { GNUNET_free (value); return GNUNET_OK; } /** * Add a new route to the given @a target via the given @a neighbor. * * @param target the target of the route * @param neighbor the next hop for communicating with the @a target */ static void add_new_route (struct Target *target, struct DirectNeighbor *neighbor) { struct Route *route; route = GNUNET_new (struct Route); route->next_hop = neighbor; route->target.peer = target->peer; allocate_route (route, ntohl (target->distance) + 1); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_put (all_routes, &route->target.peer, route, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); send_connect_to_plugin (&route->target.peer, ntohl (route->target.distance), neighbor->network); } /** * Multipeerhmap iterator for checking if a given route is * (now) useful to this peer. * * @param cls the direct neighbor for the given route * @param key key value stored under * @param value a 'struct Target' that may or may not be useful; not that * the distance in 'target' does not include the first hop yet * @return #GNUNET_YES to continue iteration, #GNUNET_NO to stop */ static int check_possible_route (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct DirectNeighbor *neighbor = cls; struct Target *target = value; struct Route *route; if (GNUNET_YES == GNUNET_CONTAINER_multipeermap_contains (direct_neighbors, key)) return GNUNET_YES; /* direct route, do not care about alternatives */ route = GNUNET_CONTAINER_multipeermap_get (all_routes, key); if (NULL != route) { /* we have an existing route, check how it compares with going via 'target' */ if (ntohl (route->target.distance) > ntohl (target->distance) + 1) { /* via 'target' is cheaper than the existing route; switch to alternative route! */ move_route (route, ntohl (target->distance) + 1); route->next_hop = neighbor; send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1, neighbor->network); } return GNUNET_YES; /* got a route to this target already */ } if (ntohl (target->distance) >= DEFAULT_FISHEYE_DEPTH) return GNUNET_YES; /* distance is too large to be interesting */ add_new_route (target, neighbor); return GNUNET_YES; } /** * Multipeermap iterator for finding routes that were previously * "hidden" due to a better route (called after a disconnect event). * * @param cls NULL * @param key peer identity of the given direct neighbor * @param value a `struct DirectNeighbor` to check for additional routes * @return #GNUNET_YES to continue iteration */ static int refresh_routes (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct DirectNeighbor *neighbor = value; if ( (GNUNET_YES != neighbor->connected) || (DIRECT_NEIGHBOR_COST != neighbor->distance) ) return GNUNET_YES; if (NULL != neighbor->neighbor_table) GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table, &check_possible_route, neighbor); return GNUNET_YES; } /** * Task to run #refresh_routes() on all direct neighbours. * * @param cls NULL */ static void refresh_routes_task (void *cls) { rr_task = NULL; GNUNET_CONTAINER_multipeermap_iterate (direct_neighbors, &refresh_routes, NULL); } /** * Asynchronously run #refresh_routes() at the next opportunity * on all direct neighbours. */ static void schedule_refresh_routes () { if (NULL == rr_task) rr_task = GNUNET_SCHEDULER_add_now (&refresh_routes_task, NULL); } /** * Multipeermap iterator for freeing routes that go via a particular * neighbor that disconnected and is thus no longer available. * * @param cls the direct neighbor that is now unavailable * @param key key value stored under * @param value a `struct Route` that may or may not go via neighbor * * @return #GNUNET_YES to continue iteration, #GNUNET_NO to stop */ static int cull_routes (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct DirectNeighbor *neighbor = cls; struct Route *route = value; if (route->next_hop != neighbor) return GNUNET_YES; /* not affected */ GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (all_routes, key, value)); release_route (route); send_disconnect_to_plugin (&route->target.peer); GNUNET_free (route); return GNUNET_YES; } /** * Handle the case that a direct connection to a peer is * disrupted. Remove all routes via that peer and * stop the consensus with it. * * @param neighbor peer that was disconnected (or at least is no * longer at distance 1) */ static void handle_direct_disconnect (struct DirectNeighbor *neighbor) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Culling routes via %s due to direct disconnect\n", GNUNET_i2s (&neighbor->peer)); GNUNET_CONTAINER_multipeermap_iterate (all_routes, &cull_routes, neighbor); if (NULL != neighbor->direct_route) { release_route (neighbor->direct_route); GNUNET_free (neighbor->direct_route); neighbor->direct_route = NULL; } if (NULL != neighbor->neighbor_table_consensus) { GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table_consensus, &free_targets, NULL); GNUNET_CONTAINER_multipeermap_destroy (neighbor->neighbor_table_consensus); neighbor->neighbor_table_consensus = NULL; } if (NULL != neighbor->neighbor_table) { GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table, &free_targets, NULL); GNUNET_CONTAINER_multipeermap_destroy (neighbor->neighbor_table); neighbor->neighbor_table = NULL; } if (NULL != neighbor->set_op) { GNUNET_SET_operation_cancel (neighbor->set_op); neighbor->set_op = NULL; } if (NULL != neighbor->my_set) { GNUNET_SET_destroy (neighbor->my_set); neighbor->my_set = NULL; } if (NULL != neighbor->listen_handle) { GNUNET_SET_listen_cancel (neighbor->listen_handle); neighbor->listen_handle = NULL; } if (NULL != neighbor->initiate_task) { GNUNET_SCHEDULER_cancel (neighbor->initiate_task); neighbor->initiate_task = NULL; } } /** * Function that is called with QoS information about an address; used * to update our current distance to another peer. * * @param cls closure * @param address the address * @param active #GNUNET_YES if this address is actively used * to maintain a connection to a peer; * #GNUNET_NO if the address is not actively used; * #GNUNET_SYSERR if this address is no longer available for ATS * @param bandwidth_out assigned outbound bandwidth for the connection * @param bandwidth_in assigned inbound bandwidth for the connection * @param prop performance data for the address (as far as known) */ static void handle_ats_update (void *cls, const struct GNUNET_HELLO_Address *address, int active, struct GNUNET_BANDWIDTH_Value32NBO bandwidth_out, struct GNUNET_BANDWIDTH_Value32NBO bandwidth_in, const struct GNUNET_ATS_Properties *prop) { struct DirectNeighbor *neighbor; uint32_t distance; enum GNUNET_ATS_Network_Type network; if (NULL == address) { /* ATS service temporarily disconnected */ return; } if (GNUNET_YES != active) { // FIXME: handle disconnect/inactive case too! return; } distance = prop->distance; network = prop->scope; GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network); /* check if entry exists */ neighbor = GNUNET_CONTAINER_multipeermap_get (direct_neighbors, &address->peer); if (NULL != neighbor) { neighbor->network = network; if (neighbor->distance == distance) return; /* nothing new to see here, move along */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "ATS says distance to %s is now %u\n", GNUNET_i2s (&address->peer), (unsigned int) distance); if ( (DIRECT_NEIGHBOR_COST == neighbor->distance) && (DIRECT_NEIGHBOR_COST == distance) ) return; /* no change */ if (DIRECT_NEIGHBOR_COST == neighbor->distance) { neighbor->distance = distance; GNUNET_STATISTICS_update (stats, "# peers connected (1-hop)", -1, GNUNET_NO); handle_direct_disconnect (neighbor); schedule_refresh_routes (); return; } neighbor->distance = distance; if (DIRECT_NEIGHBOR_COST != neighbor->distance) return; if (GNUNET_YES != neighbor->connected) return; handle_direct_connect (neighbor); return; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "ATS says distance to %s is now %u\n", GNUNET_i2s (&address->peer), (unsigned int) distance); neighbor = GNUNET_new (struct DirectNeighbor); neighbor->peer = address->peer; GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_put (direct_neighbors, &neighbor->peer, neighbor, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); neighbor->connected = GNUNET_NO; /* not yet */ neighbor->distance = distance; neighbor->network = network; } /** * Check if a target was removed from the set of the other peer; if so, * if we also used it for our route, we need to remove it from our * 'all_routes' set (and later check if an alternative path now exists). * * @param cls the `struct DirectNeighbor` * @param key peer identity for the target * @param value a `struct Target` previously reachable via the given neighbor */ static int check_target_removed (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct DirectNeighbor *neighbor = cls; struct Target *new_target; struct Route *current_route; new_target = GNUNET_CONTAINER_multipeermap_get (neighbor->neighbor_table_consensus, key); current_route = GNUNET_CONTAINER_multipeermap_get (all_routes, key); if (NULL != new_target) { /* target was in old set, is in new set */ if ( (NULL != current_route) && (current_route->next_hop == neighbor) && (current_route->target.distance != new_target->distance) ) { /* need to recalculate routes due to distance change */ neighbor->target_removed = GNUNET_YES; } return GNUNET_OK; } /* target was revoked, check if it was used */ if ( (NULL == current_route) || (current_route->next_hop != neighbor) ) { /* didn't matter, wasn't used */ return GNUNET_OK; } /* remove existing route */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Lost route to %s\n", GNUNET_i2s (¤t_route->target.peer)); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (all_routes, key, current_route)); send_disconnect_to_plugin (¤t_route->target.peer); release_route (current_route); GNUNET_free (current_route); neighbor->target_removed = GNUNET_YES; return GNUNET_OK; } /** * Check if a target was added to the set of the other peer; if it * was added or impoves the existing route, do the needed updates. * * @param cls the `struct DirectNeighbor` * @param key peer identity for the target * @param value a `struct Target` now reachable via the given neighbor */ static int check_target_added (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct DirectNeighbor *neighbor = cls; struct Target *target = value; struct Route *current_route; /* target was revoked, check if it was used */ current_route = GNUNET_CONTAINER_multipeermap_get (all_routes, key); if (NULL != current_route) { /* route exists */ if (current_route->next_hop == neighbor) { /* we had the same route before, no change in target */ if (ntohl (target->distance) + 1 != ntohl (current_route->target.distance)) { /* but distance changed! */ if (ntohl (target->distance) + 1 > DEFAULT_FISHEYE_DEPTH) { /* distance increased beyond what is allowed, kill route */ GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (all_routes, key, current_route)); send_disconnect_to_plugin (key); release_route (current_route); GNUNET_free (current_route); } else { /* distance decreased, update route */ move_route (current_route, ntohl (target->distance) + 1); send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1, neighbor->network); } } return GNUNET_OK; } if (ntohl (current_route->target.distance) <= ntohl (target->distance) + 1) { /* alternative, shorter route exists, ignore */ return GNUNET_OK; } /* new route is better than the existing one, take over! */ /* NOTE: minor security issue: malicious peers may advertise very short routes to take over longer paths; as we don't check that the shorter routes actually work, a malicious direct neighbor can use this to DoS our long routes */ move_route (current_route, ntohl (target->distance) + 1); current_route->next_hop = neighbor; send_distance_change_to_plugin (&target->peer, ntohl (target->distance) + 1, neighbor->network); return GNUNET_OK; } /* new route */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Discovered new route to %s using %u hops\n", GNUNET_i2s (&target->peer), (unsigned int) (ntohl (target->distance) + 1)); current_route = GNUNET_new (struct Route); current_route->next_hop = neighbor; current_route->target.peer = target->peer; allocate_route (current_route, ntohl (target->distance) + 1); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_put (all_routes, ¤t_route->target.peer, current_route, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); send_connect_to_plugin (¤t_route->target.peer, ntohl (current_route->target.distance), neighbor->network); return GNUNET_OK; } /** * Callback for set operation results. Called for each element * in the result set. * We have learned a new route from the other peer. Add it to the * route set we're building. * * @param cls the `struct DirectNeighbor` we're building the consensus with * @param element a result element, only valid if status is #GNUNET_SET_STATUS_OK * @param current_size current set size * @param status see `enum GNUNET_SET_Status` */ static void handle_set_union_result (void *cls, const struct GNUNET_SET_Element *element, uint64_t current_size, enum GNUNET_SET_Status status) { struct DirectNeighbor *neighbor = cls; struct DirectNeighbor *dn; struct Target *target; const struct Target *ctarget; char *status_str; switch (status) { case GNUNET_SET_STATUS_OK: status_str = "GNUNET_SET_STATUS_OK"; break; case GNUNET_SET_STATUS_FAILURE: status_str = "GNUNET_SET_STATUS_FAILURE"; break; case GNUNET_SET_STATUS_HALF_DONE: status_str = "GNUNET_SET_STATUS_HALF_DONE"; break; case GNUNET_SET_STATUS_DONE: status_str = "GNUNET_SET_STATUS_DONE"; break; default: status_str = "UNDEFINED"; break; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Got SET union result: %s\n", status_str); switch (status) { case GNUNET_SET_STATUS_OK: if (sizeof (struct Target) != element->size) { GNUNET_break_op (0); return; } ctarget = element->data; if ( (NULL != (dn = GNUNET_CONTAINER_multipeermap_get (direct_neighbors, &ctarget->peer))) && (DIRECT_NEIGHBOR_COST == dn->distance) ) { /* this is a direct neighbor of ours, we do not care about routes to this peer */ return; } target = GNUNET_new (struct Target); GNUNET_memcpy (target, element->data, sizeof (struct Target)); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received information about peer `%s' with distance %u from SET\n", GNUNET_i2s (&target->peer), ntohl (target->distance) + 1); if (NULL == neighbor->neighbor_table_consensus) neighbor->neighbor_table_consensus = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO); if (GNUNET_YES != GNUNET_CONTAINER_multipeermap_put (neighbor->neighbor_table_consensus, &target->peer, target, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { GNUNET_break_op (0); GNUNET_free (target); } break; case GNUNET_SET_STATUS_FAILURE: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Failed to establish DV union, will try again later\n"); neighbor->set_op = NULL; if (NULL != neighbor->neighbor_table_consensus) { GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table_consensus, &free_targets, NULL); GNUNET_CONTAINER_multipeermap_destroy (neighbor->neighbor_table_consensus); neighbor->neighbor_table_consensus = NULL; } if (0 < memcmp (&neighbor->peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))) neighbor->initiate_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY, &initiate_set_union, neighbor); break; case GNUNET_SET_STATUS_HALF_DONE: break; case GNUNET_SET_STATUS_DONE: /* we got all of our updates; integrate routing table! */ neighbor->target_removed = GNUNET_NO; if (NULL == neighbor->neighbor_table_consensus) neighbor->neighbor_table_consensus = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO); if (NULL != neighbor->neighbor_table) GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table, &check_target_removed, neighbor); if (GNUNET_YES == neighbor->target_removed) { /* check if we got an alternative for the removed routes */ schedule_refresh_routes (); } /* add targets that appeared (and check for improved routes) */ GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table_consensus, &check_target_added, neighbor); if (NULL != neighbor->neighbor_table) { GNUNET_CONTAINER_multipeermap_iterate (neighbor->neighbor_table, &free_targets, NULL); GNUNET_CONTAINER_multipeermap_destroy (neighbor->neighbor_table); neighbor->neighbor_table = NULL; } neighbor->neighbor_table = neighbor->neighbor_table_consensus; neighbor->neighbor_table_consensus = NULL; /* operation done, schedule next run! */ neighbor->set_op = NULL; if (0 < memcmp (&neighbor->peer, &my_identity, sizeof (struct GNUNET_PeerIdentity))) neighbor->initiate_task = GNUNET_SCHEDULER_add_delayed (GNUNET_DV_CONSENSUS_FREQUENCY, &initiate_set_union, neighbor); break; default: GNUNET_break (0); return; } } /** * Start creating a new DV set union construction, our neighbour has * asked for it (callback for listening peer). * * @param cls the 'struct DirectNeighbor' of the peer we're building * a routing consensus with * @param other_peer the other peer * @param context_msg message with application specific information from * the other peer * @param request request from the other peer, use GNUNET_SET_accept * to accept it, otherwise the request will be refused * Note that we don't use a return value here, as it is also * necessary to specify the set we want to do the operation with, * whith sometimes can be derived from the context message. * Also necessary to specify the timeout. */ static void listen_set_union (void *cls, const struct GNUNET_PeerIdentity *other_peer, const struct GNUNET_MessageHeader *context_msg, struct GNUNET_SET_Request *request) { struct DirectNeighbor *neighbor = cls; if (NULL == request) return; /* why??? */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting to create consensus with %s\n", GNUNET_i2s (&neighbor->peer)); if (NULL != neighbor->set_op) { GNUNET_SET_operation_cancel (neighbor->set_op); neighbor->set_op = NULL; } if (NULL != neighbor->my_set) { GNUNET_SET_destroy (neighbor->my_set); neighbor->my_set = NULL; } neighbor->my_set = GNUNET_SET_create (cfg, GNUNET_SET_OPERATION_UNION); neighbor->set_op = GNUNET_SET_accept (request, GNUNET_SET_RESULT_ADDED, (struct GNUNET_SET_Option[]) {{ 0 }}, &handle_set_union_result, neighbor); neighbor->consensus_insertion_offset = 0; neighbor->consensus_insertion_distance = 0; neighbor->consensus_elements = 0; build_set (neighbor); } /** * Start creating a new DV set union by initiating the connection. * * @param cls the `struct DirectNeighbor *` of the peer we're building * a routing consensus with */ static void initiate_set_union (void *cls) { struct DirectNeighbor *neighbor = cls; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Initiating SET union with peer `%s'\n", GNUNET_i2s (&neighbor->peer)); neighbor->initiate_task = NULL; neighbor->my_set = GNUNET_SET_create (cfg, GNUNET_SET_OPERATION_UNION); neighbor->set_op = GNUNET_SET_prepare (&neighbor->peer, &neighbor->real_session_id, NULL, GNUNET_SET_RESULT_ADDED, (struct GNUNET_SET_Option[]) {{ 0 }}, &handle_set_union_result, neighbor); neighbor->consensus_insertion_offset = 0; neighbor->consensus_insertion_distance = 0; neighbor->consensus_elements = 0; build_set (neighbor); } /** * Check that @a rm is well-formed. * * @param cls closure * @param rm the message * @return #GNUNET_OK if @a rm is well-formed. */ static int check_dv_route_message (void *cls, const struct RouteMessage *rm) { const struct GNUNET_MessageHeader *payload; if (ntohs (rm->header.size) < sizeof (struct RouteMessage) + sizeof (struct GNUNET_MessageHeader)) { GNUNET_break_op (0); return GNUNET_SYSERR; } payload = (const struct GNUNET_MessageHeader *) &rm[1]; if (ntohs (rm->header.size) != sizeof (struct RouteMessage) + ntohs (payload->size)) { GNUNET_break_op (0); return GNUNET_SYSERR; } return GNUNET_OK; } /** * Core handler for DV data messages. Whatever this message * contains all we really have to do is rip it out of its * DV layering and give it to our pal the DV plugin to report * in with. * * @param cls closure * @param rm the message */ static void handle_dv_route_message (void *cls, const struct RouteMessage *rm) { struct DirectNeighbor *neighbor = cls; const struct GNUNET_MessageHeader *payload; struct Route *route; struct DirectNeighbor *nneighbor; struct DirectNeighbor *dn; struct Target *target; uint32_t distance; char me[5]; char src[5]; char prev[5]; char dst[5]; distance = ntohl (rm->distance); payload = (const struct GNUNET_MessageHeader *) &rm[1]; strncpy (prev, GNUNET_i2s (&neighbor->peer), 4); strncpy (me, GNUNET_i2s (&my_identity), 4); strncpy (src, GNUNET_i2s (&rm->sender), 4); strncpy (dst, GNUNET_i2s (&rm->target), 4); prev[4] = me[4] = src[4] = dst[4] = '\0'; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Handling DV message with %u bytes payload of type %u from %s to %s routed by %s to me (%s @ hop %u)\n", (unsigned int) (ntohs (rm->header.size) - sizeof (struct RouteMessage)), ntohs (payload->type), src, dst, prev, me, (unsigned int) distance + 1); if (0 == memcmp (&rm->target, &my_identity, sizeof (struct GNUNET_PeerIdentity))) { if ((NULL != (dn = GNUNET_CONTAINER_multipeermap_get (direct_neighbors, &rm->sender))) && (DIRECT_NEIGHBOR_COST == dn->distance)) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Discarding DV message, as %s is a direct neighbor\n", GNUNET_i2s (&rm->sender)); GNUNET_STATISTICS_update (stats, "# messages discarded (direct neighbor)", 1, GNUNET_NO); return; } /* message is for me, check reverse route! */ route = GNUNET_CONTAINER_multipeermap_get (all_routes, &rm->sender); if ( (NULL == route) && (distance < DEFAULT_FISHEYE_DEPTH) ) { /* don't have reverse route yet, learn it! */ target = GNUNET_new (struct Target); target->peer = rm->sender; target->distance = htonl (distance); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Learning sender %s at distance %u from delivery!\n", GNUNET_i2s (&rm->sender), (unsigned int) distance + 1); if (NULL == neighbor->neighbor_table) neighbor->neighbor_table = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO); if (GNUNET_YES != GNUNET_CONTAINER_multipeermap_put (neighbor->neighbor_table, &target->peer, target, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { GNUNET_break_op (0); GNUNET_free (target); return; } add_new_route (target, neighbor); } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Delivering %u bytes from %s to myself!\n", ntohs (payload->size), GNUNET_i2s (&rm->sender)); send_data_to_plugin (payload, &rm->sender, 1 + distance); return; } if ( (NULL == GNUNET_CONTAINER_multipeermap_get (direct_neighbors, &rm->sender)) && (NULL == GNUNET_CONTAINER_multipeermap_get (all_routes, &rm->sender)) ) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Learning sender %s at distance %u from forwarding!\n", GNUNET_i2s (&rm->sender), 1 + distance); target = GNUNET_new (struct Target); target->peer = rm->sender; target->distance = htonl (distance); if (NULL == neighbor->neighbor_table) neighbor->neighbor_table = GNUNET_CONTAINER_multipeermap_create (10, GNUNET_NO); if (GNUNET_YES != GNUNET_CONTAINER_multipeermap_put (neighbor->neighbor_table, &target->peer, target, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)) { GNUNET_break_op (0); GNUNET_free (target); return; } add_new_route (target, neighbor); } route = GNUNET_CONTAINER_multipeermap_get (all_routes, &rm->target); if (NULL == route) { nneighbor = GNUNET_CONTAINER_multipeermap_get (direct_neighbors, &rm->target); if (NULL == nneighbor) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "No route to %s, not routing %u bytes!\n", GNUNET_i2s (&rm->target), ntohs (payload->size)); GNUNET_STATISTICS_update (stats, "# messages discarded (no route)", 1, GNUNET_NO); return; } } else { nneighbor = route->next_hop; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Forwarding message to %s\n", GNUNET_i2s (&nneighbor->peer)); forward_payload (nneighbor, distance + 1, &rm->sender, &rm->target, payload); } /** * Check that @a msg is well-formed * * @param cls identification of the client * @param message the actual message * @return #GNUNET_OK if @a msg is well-formed */ static int check_dv_send_message (void *cls, const struct GNUNET_DV_SendMessage *msg) { const struct GNUNET_MessageHeader *payload; if (ntohs (msg->header.size) < sizeof (struct GNUNET_DV_SendMessage) + sizeof (struct GNUNET_MessageHeader)) { GNUNET_break (0); return GNUNET_SYSERR; } payload = (const struct GNUNET_MessageHeader *) &msg[1]; if (ntohs (msg->header.size) != sizeof (struct GNUNET_DV_SendMessage) + ntohs (payload->size)) { GNUNET_break (0); return GNUNET_SYSERR; } return GNUNET_OK; } /** * Service server's handler for message send requests (which come * bubbling up to us through the DV plugin). * * @param cls identification of the client * @param message the actual message */ static void handle_dv_send_message (void *cls, const struct GNUNET_DV_SendMessage *msg) { struct GNUNET_SERVICE_Client *client = cls; struct Route *route; const struct GNUNET_MessageHeader *payload; payload = (const struct GNUNET_MessageHeader *) &msg[1]; route = GNUNET_CONTAINER_multipeermap_get (all_routes, &msg->target); if (NULL == route) { /* got disconnected */ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "No route to %s, dropping local message of type %u\n", GNUNET_i2s (&msg->target), ntohs (payload->type)); GNUNET_STATISTICS_update (stats, "# local messages discarded (no route)", 1, GNUNET_NO); GNUNET_SERVICE_client_continue (client); return; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Forwarding %u bytes of type %u to %s\n", ntohs (payload->size), ntohs (payload->type), GNUNET_i2s (&msg->target)); forward_payload (route->next_hop, 0 /* first hop, distance is zero */, &my_identity, &msg->target, payload); GNUNET_SERVICE_client_continue (client); } /** * Cleanup all of the data structures associated with a given neighbor. * * @param neighbor neighbor to clean up */ static void cleanup_neighbor (struct DirectNeighbor *neighbor) { handle_direct_disconnect (neighbor); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (direct_neighbors, &neighbor->peer, neighbor)); GNUNET_free (neighbor); } /** * Method called whenever a given peer disconnects. * * @param cls closure * @param peer peer identity this notification is about * @param internal_cls the corresponding `struct DirectNeighbor` */ static void handle_core_disconnect (void *cls, const struct GNUNET_PeerIdentity *peer, void *internal_cls) { struct DirectNeighbor *neighbor = internal_cls; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received core peer disconnect message for peer `%s'!\n", GNUNET_i2s (peer)); /* Check for disconnect from self message */ if (NULL == neighbor) return; GNUNET_break (GNUNET_YES == neighbor->connected); neighbor->connected = GNUNET_NO; if (DIRECT_NEIGHBOR_COST == neighbor->distance) { GNUNET_STATISTICS_update (stats, "# peers connected (1-hop)", -1, GNUNET_NO); } cleanup_neighbor (neighbor); if (GNUNET_YES == in_shutdown) return; schedule_refresh_routes (); } /** * Multipeermap iterator for freeing routes. Should never be called. * * @param cls NULL * @param key key value stored under * @param value the route to be freed * @return #GNUNET_YES to continue iteration, #GNUNET_NO to stop */ static int free_route (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct Route *route = value; GNUNET_break (0); GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multipeermap_remove (all_routes, key, value)); release_route (route); send_disconnect_to_plugin (&route->target.peer); GNUNET_free (route); return GNUNET_YES; } /** * Multipeermap iterator for freeing direct neighbors. Should never be called. * * @param cls NULL * @param key key value stored under * @param value the direct neighbor to be freed * @return #GNUNET_YES to continue iteration, #GNUNET_NO to stop */ static int free_direct_neighbors (void *cls, const struct GNUNET_PeerIdentity *key, void *value) { struct DirectNeighbor *neighbor = value; cleanup_neighbor (neighbor); return GNUNET_YES; } /** * Task run during shutdown. * * @param cls unused */ static void shutdown_task (void *cls) { unsigned int i; in_shutdown = GNUNET_YES; GNUNET_assert (NULL != core_api); GNUNET_CORE_disconnect (core_api); core_api = NULL; GNUNET_ATS_performance_done (ats); ats = NULL; GNUNET_CONTAINER_multipeermap_iterate (direct_neighbors, &free_direct_neighbors, NULL); GNUNET_CONTAINER_multipeermap_iterate (all_routes, &free_route, NULL); GNUNET_CONTAINER_multipeermap_destroy (direct_neighbors); GNUNET_CONTAINER_multipeermap_destroy (all_routes); GNUNET_STATISTICS_destroy (stats, GNUNET_NO); stats = NULL; GNUNET_notification_context_destroy (nc); nc = NULL; for (i=0;idistance = htonl (route->target.distance); cm->peer = route->target.peer; GNUNET_MQ_send (GNUNET_SERVICE_client_get_mq (client), env); return GNUNET_OK; } /** * Handle START-message. This is the first message sent to us * by the client (can only be one!). * * @param cls closure (always NULL) * @param client identification of the client * @param message the actual message */ static void handle_start (void *cls, const struct GNUNET_MessageHeader *message) { struct GNUNET_SERVICE_Client *client = cls; GNUNET_notification_context_add (nc, GNUNET_SERVICE_client_get_mq (client)); GNUNET_SERVICE_client_continue (client); GNUNET_CONTAINER_multipeermap_iterate (all_routes, ¬ify_client_about_route, client); } /** * Called on core init. * * @param cls unused * @param identity this peer's identity */ static void core_init (void *cls, const struct GNUNET_PeerIdentity *identity) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "I am peer: %s\n", GNUNET_i2s (identity)); my_identity = *identity; } /** * Process dv requests. * * @param cls closure * @param c configuration to use * @param service the initialized service */ static void run (void *cls, const struct GNUNET_CONFIGURATION_Handle *c, struct GNUNET_SERVICE_Handle *service) { struct GNUNET_MQ_MessageHandler core_handlers[] = { GNUNET_MQ_hd_var_size (dv_route_message, GNUNET_MESSAGE_TYPE_DV_ROUTE, struct RouteMessage, NULL), GNUNET_MQ_handler_end () }; in_shutdown = GNUNET_NO; cfg = c; direct_neighbors = GNUNET_CONTAINER_multipeermap_create (128, GNUNET_NO); all_routes = GNUNET_CONTAINER_multipeermap_create (65536, GNUNET_NO); core_api = GNUNET_CORE_connect (cfg, NULL, &core_init, &handle_core_connect, &handle_core_disconnect, core_handlers); if (NULL == core_api) return; ats = GNUNET_ATS_performance_init (cfg, &handle_ats_update, NULL); if (NULL == ats) { GNUNET_CORE_disconnect (core_api); core_api = NULL; return; } nc = GNUNET_notification_context_create (MAX_QUEUE_SIZE_PLUGIN); stats = GNUNET_STATISTICS_create ("dv", cfg); GNUNET_SCHEDULER_add_shutdown (&shutdown_task, NULL); } /** * Callback called when a client connects to the service. * * @param cls closure for the service * @param c the new client that connected to the service * @param mq the message queue used to send messages to the client * @return @a c */ static void * client_connect_cb (void *cls, struct GNUNET_SERVICE_Client *c, struct GNUNET_MQ_Handle *mq) { return c; } /** * Callback called when a client disconnected from the service * * @param cls closure for the service * @param c the client that disconnected * @param internal_cls should be equal to @a c */ static void client_disconnect_cb (void *cls, struct GNUNET_SERVICE_Client *c, void *internal_cls) { GNUNET_assert (c == internal_cls); } /** * Define "main" method using service macro. */ GNUNET_SERVICE_MAIN ("dv", GNUNET_SERVICE_OPTION_NONE, &run, &client_connect_cb, &client_disconnect_cb, NULL, GNUNET_MQ_hd_fixed_size (start, GNUNET_MESSAGE_TYPE_DV_START, struct GNUNET_MessageHeader, NULL), GNUNET_MQ_hd_var_size (dv_send_message, GNUNET_MESSAGE_TYPE_DV_SEND, struct GNUNET_DV_SendMessage, NULL), GNUNET_MQ_handler_end ()); /* end of gnunet-service-dv.c */