/* 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/dht_api.c * @brief library to access the DHT service * @author Christian Grothoff * @author Nathan Evans */ #include "platform.h" #include "gnunet_bandwidth_lib.h" #include "gnunet_client_lib.h" #include "gnunet_constants.h" #include "gnunet_container_lib.h" #include "gnunet_arm_service.h" #include "gnunet_hello_lib.h" #include "gnunet_protocols.h" #include "gnunet_server_lib.h" #include "gnunet_time_lib.h" #include "gnunet_dht_service.h" #include "dht.h" #define DEBUG_DHT_API GNUNET_NO /** * Entry in our list of messages to be (re-)transmitted. */ struct PendingMessage { /** * This is a doubly-linked list. */ struct PendingMessage *prev; /** * This is a doubly-linked list. */ struct PendingMessage *next; /** * Message that is pending, allocated at the end * of this struct. */ const struct GNUNET_MessageHeader *msg; /** * Handle to the DHT API context. */ struct GNUNET_DHT_Handle *handle; /** * Continuation to call when the request has been * transmitted (for the first time) to the service; can be NULL. */ GNUNET_SCHEDULER_Task cont; /** * Closure for 'cont'. */ void *cont_cls; /** * Timeout task for this message */ GNUNET_SCHEDULER_TaskIdentifier timeout_task; /** * Unique ID for this request */ uint64_t unique_id; /** * Free the saved message once sent, set to GNUNET_YES for messages * that do not receive responses; GNUNET_NO if this pending message * is aliased from a 'struct GNUNET_DHT_RouteHandle' and will be freed * from there. */ int free_on_send; /** * GNUNET_YES if this message is in our pending queue right now. */ int in_pending_queue; }; /** * Handle to a route request */ struct GNUNET_DHT_RouteHandle { /** * Iterator to call on data receipt */ GNUNET_DHT_ReplyProcessor iter; /** * Closure for the iterator callback */ void *iter_cls; /** * Main handle to this DHT api */ struct GNUNET_DHT_Handle *dht_handle; /** * The actual message sent for this request, * used for retransmitting requests on service * failure/reconnect. Freed on route_stop. */ struct PendingMessage *message; /** * Key that this get request is for */ GNUNET_HashCode key; /** * Unique identifier for this request (for key collisions). FIXME: redundant!? */ uint64_t uid; }; /** * Connection to the DHT service. */ struct GNUNET_DHT_Handle { /** * Configuration to use. */ const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Socket (if available). */ struct GNUNET_CLIENT_Connection *client; /** * Currently pending transmission request (or NULL). */ struct GNUNET_CLIENT_TransmitHandle *th; /** * Head of linked list of messages we would like to transmit. */ struct PendingMessage *pending_head; /** * Tail of linked list of messages we would like to transmit. */ struct PendingMessage *pending_tail; /** * Hash map containing the current outstanding unique requests * (values are of type 'struct GNUNET_DHT_RouteHandle'). */ struct GNUNET_CONTAINER_MultiHashMap *active_requests; /** * Task for trying to reconnect. */ GNUNET_SCHEDULER_TaskIdentifier reconnect_task; /** * How quickly should we retry? Used for exponential back-off on * connect-errors. */ struct GNUNET_TIME_Relative retry_time; /** * Generator for unique ids. */ uint64_t uid_gen; }; /** * Transmit the next pending message, called by notify_transmit_ready */ static size_t transmit_pending (void *cls, size_t size, void *buf); /** * Handler for messages received from the DHT service * a demultiplexer which handles numerous message types * */ static void service_message_handler (void *cls, const struct GNUNET_MessageHeader *msg); /** * Try to (re)connect to the DHT service. * * @return GNUNET_YES on success, GNUNET_NO on failure. */ static int try_connect (struct GNUNET_DHT_Handle *handle) { if (handle->client != NULL) return GNUNET_OK; handle->client = GNUNET_CLIENT_connect ("dht", handle->cfg); if (handle->client == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Failed to connect to the DHT service!\n")); return GNUNET_NO; } #if DEBUG_DHT GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Starting to process replies from DHT\n"); #endif GNUNET_CLIENT_receive (handle->client, &service_message_handler, handle, GNUNET_TIME_UNIT_FOREVER_REL); return GNUNET_YES; } /** * Add the request corresponding to the given route handle * to the pending queue (if it is not already in there). * * @param cls the 'struct GNUNET_DHT_Handle*' * @param key key for the request (not used) * @param value the 'struct GNUNET_DHT_RouteHandle*' * @return GNUNET_YES (always) */ static int add_request_to_pending (void *cls, const GNUNET_HashCode *key, void *value) { struct GNUNET_DHT_Handle *handle = cls; struct GNUNET_DHT_RouteHandle *rh = value; if (GNUNET_NO == rh->message->in_pending_queue) { GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail, rh->message); rh->message->in_pending_queue = GNUNET_YES; } return GNUNET_YES; } /** * Try reconnecting to the dht service. * * @param cls GNUNET_DHT_Handle * @param tc scheduler context */ static void try_reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct GNUNET_DHT_Handle *handle = cls; handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK; if (handle->retry_time.rel_value < GNUNET_CONSTANTS_SERVICE_RETRY.rel_value) handle->retry_time = GNUNET_CONSTANTS_SERVICE_RETRY; else handle->retry_time = GNUNET_TIME_relative_multiply (handle->retry_time, 2); if (handle->retry_time.rel_value > GNUNET_CONSTANTS_SERVICE_TIMEOUT.rel_value) handle->retry_time = GNUNET_CONSTANTS_SERVICE_TIMEOUT; handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK; handle->client = GNUNET_CLIENT_connect ("dht", handle->cfg); if (handle->client == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "dht reconnect failed(!)\n"); return; } GNUNET_CONTAINER_multihashmap_iterate (handle->active_requests, &add_request_to_pending, handle); if (handle->pending_head == NULL) return; GNUNET_CLIENT_notify_transmit_ready (handle->client, ntohs(handle->pending_head->msg->size), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_NO, &transmit_pending, handle); } /** * Try reconnecting to the DHT service. * * @param handle handle to dht to (possibly) disconnect and reconnect */ static void do_disconnect (struct GNUNET_DHT_Handle *handle) { if (handle->client == NULL) return; GNUNET_assert(handle->reconnect_task == GNUNET_SCHEDULER_NO_TASK); GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO); handle->client = NULL; handle->reconnect_task = GNUNET_SCHEDULER_add_delayed (handle->retry_time, &try_reconnect, handle); } /** * Try to send messages from list of messages to send */ static void process_pending_messages (struct GNUNET_DHT_Handle *handle) { struct PendingMessage *head; if (handle->client == NULL) { do_disconnect(handle); return; } if (handle->th != NULL) return; if (NULL == (head = handle->pending_head)) return; handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client, ntohs (head->msg->size), GNUNET_TIME_UNIT_FOREVER_REL, GNUNET_YES, &transmit_pending, handle); if (NULL == handle->th) { do_disconnect (handle); return; } } /** * Transmit the next pending message, called by notify_transmit_ready */ static size_t transmit_pending (void *cls, size_t size, void *buf) { struct GNUNET_DHT_Handle *handle = cls; struct PendingMessage *head; size_t tsize; handle->th = NULL; if (buf == NULL) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Transmission to DHT service failed! Reconnecting!\n"); do_disconnect (handle); return 0; } if (NULL == (head = handle->pending_head)) return 0; tsize = ntohs (head->msg->size); if (size < tsize) { process_pending_messages (handle); return 0; } memcpy (buf, head->msg, tsize); GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail, head); if (head->timeout_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (head->timeout_task); head->timeout_task = GNUNET_SCHEDULER_NO_TASK; } if (NULL != head->cont) { GNUNET_SCHEDULER_add_continuation (head->cont, head->cont_cls, GNUNET_SCHEDULER_REASON_PREREQ_DONE); head->cont = NULL; head->cont_cls = NULL; } head->in_pending_queue = GNUNET_NO; if (GNUNET_YES == head->free_on_send) GNUNET_free (head); process_pending_messages (handle); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Forwarded request of %u bytes to DHT service\n", (unsigned int) tsize); return tsize; } /** * Process a given reply that might match the given * request. */ static int process_reply (void *cls, const GNUNET_HashCode *key, void *value) { const struct GNUNET_DHT_RouteResultMessage *dht_msg = cls; struct GNUNET_DHT_RouteHandle *rh = value; const struct GNUNET_MessageHeader *enc_msg; size_t enc_size; uint64_t uid; const struct GNUNET_PeerIdentity **outgoing_path; const struct GNUNET_PeerIdentity *pos; uint32_t outgoing_path_length; unsigned int i; char *path_offset; uid = GNUNET_ntohll (dht_msg->unique_id); if (uid != rh->uid) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Reply UID did not match request UID\n"); return GNUNET_YES; } enc_msg = (const struct GNUNET_MessageHeader *)&dht_msg[1]; enc_size = ntohs (enc_msg->size); if (enc_size < sizeof (struct GNUNET_MessageHeader)) { GNUNET_break (0); return GNUNET_NO; } path_offset = (char *)&dht_msg[1]; path_offset += enc_size; pos = (const struct GNUNET_PeerIdentity *) path_offset; outgoing_path_length = ntohl (dht_msg->outgoing_path_length); if (outgoing_path_length * sizeof (struct GNUNET_PeerIdentity) > ntohs(dht_msg->header.size) - enc_size) { GNUNET_break (0); return GNUNET_NO; } if (outgoing_path_length > 0) { outgoing_path = GNUNET_malloc ((outgoing_path_length + 1) * sizeof (struct GNUNET_PeerIdentity*)); for (i = 0; i < outgoing_path_length; i++) { outgoing_path[i] = pos; pos++; } outgoing_path[outgoing_path_length] = NULL; } else outgoing_path = NULL; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Processing reply.\n"); rh->iter (rh->iter_cls, &rh->key, outgoing_path, enc_msg); GNUNET_free_non_null (outgoing_path); return GNUNET_YES; } /** * Handler for messages received from the DHT service * a demultiplexer which handles numerous message types * * @param cls the 'struct GNUNET_DHT_Handle' * @param msg the incoming message */ static void service_message_handler (void *cls, const struct GNUNET_MessageHeader *msg) { struct GNUNET_DHT_Handle *handle = cls; const struct GNUNET_DHT_RouteResultMessage *dht_msg; if (msg == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Error receiving data from DHT service, reconnecting\n"); do_disconnect (handle); return; } if (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_RESULT) { GNUNET_break (0); do_disconnect (handle); return; } if (ntohs (msg->size) < sizeof (struct GNUNET_DHT_RouteResultMessage)) { GNUNET_break (0); do_disconnect (handle); return; } dht_msg = (const struct GNUNET_DHT_RouteResultMessage *) msg; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Comparing reply `%s' against %u pending requests.\n", GNUNET_h2s (&dht_msg->key), GNUNET_CONTAINER_multihashmap_size (handle->active_requests)); GNUNET_CONTAINER_multihashmap_get_multiple (handle->active_requests, &dht_msg->key, &process_reply, (void*) dht_msg); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Continuing to process replies from DHT\n"); GNUNET_CLIENT_receive (handle->client, &service_message_handler, handle, GNUNET_TIME_UNIT_FOREVER_REL); } /** * Initialize the connection with the DHT service. * * @param cfg configuration to use * @param ht_len size of the internal hash table to use for * processing multiple GET/FIND requests in parallel * * @return handle to the DHT service, or NULL on error */ struct GNUNET_DHT_Handle * GNUNET_DHT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int ht_len) { struct GNUNET_DHT_Handle *handle; handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_Handle)); handle->cfg = cfg; handle->uid_gen = GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_WEAK, UINT64_MAX); handle->active_requests = GNUNET_CONTAINER_multihashmap_create (ht_len); if (GNUNET_NO == try_connect (handle)) { GNUNET_DHT_disconnect (handle); return NULL; } return handle; } /** * Shutdown connection with the DHT service. * * @param handle handle of the DHT connection to stop */ void GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle) { struct PendingMessage *pm; GNUNET_assert(handle != NULL); GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size(handle->active_requests)); if (handle->th != NULL) { GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th); handle->th = NULL; } while (NULL != (pm = handle->pending_head)) { GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail, pm); GNUNET_assert (GNUNET_YES == pm->free_on_send); if (GNUNET_SCHEDULER_NO_TASK != pm->timeout_task) GNUNET_SCHEDULER_cancel (pm->timeout_task); if (NULL != pm->cont) GNUNET_SCHEDULER_add_continuation (pm->cont, pm->cont_cls, GNUNET_SCHEDULER_REASON_TIMEOUT); pm->in_pending_queue = GNUNET_NO; GNUNET_free (pm); } if (handle->client != NULL) { GNUNET_CLIENT_disconnect (handle->client, GNUNET_YES); handle->client = NULL; } if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK) GNUNET_SCHEDULER_cancel(handle->reconnect_task); GNUNET_CONTAINER_multihashmap_destroy(handle->active_requests); GNUNET_free (handle); } /* ***** Special low-level API providing generic routing abstraction ***** */ /** * Timeout for the transmission of a fire&forget-request. Clean it up. * * @param cls the 'struct PendingMessage' * @param tc scheduler context */ static void timeout_route_request (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct PendingMessage *pending = cls; struct GNUNET_DHT_Handle *handle; if (pending->free_on_send != GNUNET_YES) { /* timeouts should only apply to fire & forget requests! */ GNUNET_break (0); return; } handle = pending->handle; GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail, pending); if (pending->cont != NULL) pending->cont (pending->cont_cls, tc); GNUNET_free (pending); } /** * Initiate a generic DHT route operation. * * @param handle handle to the DHT service * @param key the key to look up * @param desired_replication_level how many peers should ultimately receive * this message (advisory only, target may be too high for the * given DHT or not hit exactly). * @param options options for routing * @param enc send the encapsulated message to a peer close to the key * @param iter function to call on each result, NULL if no replies are expected * @param iter_cls closure for iter * @param timeout when to abort with an error if we fail to get * a confirmation for the request (when necessary) or how long * to wait for tramission to the service; only applies * if 'iter' is NULL * @param cont continuation to call when the request has been transmitted * the first time to the service * @param cont_cls closure for cont * @return handle to stop the request, NULL if the request is "fire and forget" */ struct GNUNET_DHT_RouteHandle * GNUNET_DHT_route_start (struct GNUNET_DHT_Handle *handle, const GNUNET_HashCode *key, uint32_t desired_replication_level, enum GNUNET_DHT_RouteOption options, const struct GNUNET_MessageHeader *enc, struct GNUNET_TIME_Relative timeout, GNUNET_DHT_ReplyProcessor iter, void *iter_cls, GNUNET_SCHEDULER_Task cont, void *cont_cls) { struct PendingMessage *pending; struct GNUNET_DHT_RouteMessage *message; struct GNUNET_DHT_RouteHandle *route_handle; uint16_t msize; uint16_t esize; esize = ntohs (enc->size); if (sizeof (struct GNUNET_DHT_RouteMessage) + esize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); return NULL; } msize = sizeof (struct GNUNET_DHT_RouteMessage) + esize; pending = GNUNET_malloc (sizeof (struct PendingMessage) + msize); message = (struct GNUNET_DHT_RouteMessage*) &pending[1]; pending->msg = &message->header; pending->handle = handle; pending->cont = cont; pending->cont_cls = cont_cls; message->header.size = htons (msize); message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE); message->key = *key; message->options = htonl ((uint32_t) options); message->desired_replication_level = htonl (desired_replication_level); handle->uid_gen++; message->unique_id = GNUNET_htonll (handle->uid_gen); memcpy (&message[1], enc, esize); if (iter != NULL) { route_handle = GNUNET_malloc (sizeof (struct GNUNET_DHT_RouteHandle)); route_handle->key = *key; route_handle->iter = iter; route_handle->iter_cls = iter_cls; route_handle->dht_handle = handle; route_handle->uid = handle->uid_gen; route_handle->message = pending; GNUNET_CONTAINER_multihashmap_put (handle->active_requests, key, route_handle, GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE); } else { route_handle = NULL; pending->free_on_send = GNUNET_YES; pending->timeout_task = GNUNET_SCHEDULER_add_delayed (timeout, &timeout_route_request, pending); } GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail, pending); pending->in_pending_queue = GNUNET_YES; process_pending_messages (handle); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "DHT route start request processed, returning %p\n", route_handle); return route_handle; } /** * Stop a previously issued routing request * * @param route_handle handle to the request to stop */ void GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle) { struct GNUNET_DHT_Handle *handle; struct PendingMessage *pending; struct GNUNET_DHT_StopMessage *message; size_t msize; handle = route_handle->dht_handle; if (GNUNET_NO == route_handle->message->in_pending_queue) { /* need to send stop message */ msize = sizeof (struct GNUNET_DHT_StopMessage); pending = GNUNET_malloc (sizeof (struct PendingMessage) + msize); message = (struct GNUNET_DHT_StopMessage*) &pending[1]; pending->msg = &message->header; message->header.size = htons (msize); message->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_LOCAL_ROUTE_STOP); message->unique_id = GNUNET_htonll (route_handle->uid); message->key = route_handle->key; pending->handle = handle; pending->free_on_send = GNUNET_YES; pending->in_pending_queue = GNUNET_YES; GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail, pending); process_pending_messages (handle); } else { /* simply remove pending request from message queue before transmission, no need to transmit STOP request! */ GNUNET_CONTAINER_DLL_remove (handle->pending_head, handle->pending_tail, route_handle->message); } GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (route_handle->dht_handle->active_requests, &route_handle->key, route_handle)); GNUNET_free(route_handle->message); GNUNET_free(route_handle); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "DHT route stop request processed\n"); } /* ***** Special API for controlling DHT routing maintenance ******* */ /** * Send a control message to the DHT. * * @param handle handle to the DHT service * @param command command * @param variable variable to the command * @param cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont */ static void send_control_message (struct GNUNET_DHT_Handle *handle, uint16_t command, uint16_t variable, GNUNET_SCHEDULER_Task cont, void *cont_cls) { struct GNUNET_DHT_ControlMessage *msg; struct PendingMessage *pending; pending = GNUNET_malloc (sizeof (struct PendingMessage) + sizeof(struct GNUNET_DHT_ControlMessage)); msg = (struct GNUNET_DHT_ControlMessage*) &pending[1]; pending->msg = &msg->header; msg->header.size = htons (sizeof(struct GNUNET_DHT_ControlMessage)); msg->header.type = htons (GNUNET_MESSAGE_TYPE_DHT_CONTROL); msg->command = htons (command); msg->variable = htons (variable); pending->free_on_send = GNUNET_YES; pending->cont = cont; pending->cont_cls = cont_cls; pending->in_pending_queue = GNUNET_YES; GNUNET_CONTAINER_DLL_insert (handle->pending_head, handle->pending_tail, pending); process_pending_messages (handle); } /** * Send a message to the DHT telling it to issue a single find * peer request using the peers unique identifier as key. This * is used to fill the routing table, and is normally controlled * by the DHT itself. However, for testing and perhaps more * close control over the DHT, this can be explicitly managed. * * @param handle handle to the DHT service * @param cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont */ void GNUNET_DHT_find_peers (struct GNUNET_DHT_Handle *handle, GNUNET_SCHEDULER_Task cont, void *cont_cls) { send_control_message (handle, GNUNET_MESSAGE_TYPE_DHT_FIND_PEER, 0, cont, cont_cls); } #if HAVE_MALICIOUS /** * Send a message to the DHT telling it to start issuing random GET * requests every 'frequency' milliseconds. * * @param handle handle to the DHT service * @param frequency delay between sending malicious messages * @param cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont */ void GNUNET_DHT_set_malicious_getter (struct GNUNET_DHT_Handle *handle, struct GNUNET_TIME_Relative frequency, GNUNET_SCHEDULER_Task cont, void *cont_cls) { if (frequency.rel_value > UINT16_MAX) { GNUNET_break (0); return; } send_control_message (handle, GNUNET_MESSAGE_TYPE_DHT_MALICIOUS_GET, frequency.rel_value, cont, cont_cls); } /** * Send a message to the DHT telling it to start issuing random PUT * requests every 'frequency' milliseconds. * * @param handle handle to the DHT service * @param frequency delay between sending malicious messages * @param cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont */ void GNUNET_DHT_set_malicious_putter (struct GNUNET_DHT_Handle *handle, struct GNUNET_TIME_Relative frequency, GNUNET_SCHEDULER_Task cont, void *cont_cls) { if (frequency.rel_value > UINT16_MAX) { GNUNET_break (0); return; } send_control_message (handle, GNUNET_MESSAGE_TYPE_DHT_MALICIOUS_PUT, frequency.rel_value, cont, cont_cls); } /** * Send a message to the DHT telling it to start dropping * all requests received. * * @param handle handle to the DHT service * @param cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont * */ void GNUNET_DHT_set_malicious_dropper (struct GNUNET_DHT_Handle *handle, GNUNET_SCHEDULER_Task cont, void *cont_cls) { send_control_message (handle, GNUNET_MESSAGE_TYPE_DHT_MALICIOUS_DROP, 0, cont, cont_cls); } #endif /* end of dht_api.c */