/* This file is part of GNUnet (C) 2004, 2005, 2006, 2008, 2009 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 include/gnunet_dht_service.h * @brief API to the DHT service * @author Christian Grothoff */ #ifndef GNUNET_DHT_SERVICE_H #define GNUNET_DHT_SERVICE_H #include "gnunet_util_lib.h" #include "gnunet_block_lib.h" #include "gnunet_hello_lib.h" #ifdef __cplusplus extern "C" { #if 0 /* keep Emacsens' auto-indent happy */ } #endif #endif /** * FIXME: document. */ #define GNUNET_DHT_DEFAULT_REPUBLISH_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 60) /** * K-value that must be used for the bloom filter 'GET' * queries. */ #define GNUNET_DHT_GET_BLOOMFILTER_K 16 /** * Non-intelligent default DHT GET replication. * Should be chosen by application if anything about * the network is known. */ #define DEFAULT_GET_REPLICATION 5 /** * Non-intelligent default DHT PUT replication. * Should be chosen by application if anything about * the network is known. */ #define DEFAULT_PUT_REPLICATION 8 /** * Connection to the DHT service. */ struct GNUNET_DHT_Handle; /** * Handle to control a route operation. */ struct GNUNET_DHT_RouteHandle; /** * Handle to control a get operation. */ struct GNUNET_DHT_GetHandle; /** * Handle to control a find peer operation. */ struct GNUNET_DHT_FindPeerHandle; /** * Options for routing. */ enum GNUNET_DHT_RouteOption { /** * Default. Do nothing special. */ GNUNET_DHT_RO_NONE = 0, /** * Each peer along the way should look at 'enc' (otherwise * only the k-peers closest to the key should look at it). */ GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE = 1, /** * We should keep track of the route that the message * took in the P2P network. */ GNUNET_DHT_RO_RECORD_ROUTE = 2, /** * Possible message option for query key randomization. */ GNUNET_DHT_RO_BART = 4 }; /** * 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 NULL on error */ struct GNUNET_DHT_Handle * GNUNET_DHT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int ht_len); /** * Shutdown connection with the DHT service. * * @param handle connection to shut down */ void GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle); /* *************** Standard API: get and put ******************* */ /** * Perform a PUT operation storing data in the DHT. * * @param handle handle to DHT service * @param key the key to store under * @param desired_replication_level estimate of how many * nearest peers this request should reach * @param options routing options for this message * @param type type of the value * @param size number of bytes in data; must be less than 64k * @param data the data to store * @param exp desired expiration time for the value * @param timeout how long to wait for transmission of this request * @param cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont * @return GNUNET_YES if put message is queued for transmission */ void GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle, const GNUNET_HashCode * key, uint32_t desired_replication_level, enum GNUNET_DHT_RouteOption options, enum GNUNET_BLOCK_Type type, size_t size, const char *data, struct GNUNET_TIME_Absolute exp, struct GNUNET_TIME_Relative timeout, GNUNET_SCHEDULER_Task cont, void *cont_cls); /** * Iterator called on each result obtained for a DHT * operation that expects a reply * * @param cls closure * @param exp when will this value expire * @param key key of the result * @param get_path NULL-terminated array of pointers * to the peers on reverse GET path (or NULL if not recorded) * @param put_path NULL-terminated array of pointers * to the peers on the PUT path (or NULL if not recorded) * @param type type of the result * @param size number of bytes in data * @param data pointer to the result data */ typedef void (*GNUNET_DHT_GetIterator)(void *cls, struct GNUNET_TIME_Absolute exp, const GNUNET_HashCode * key, const struct GNUNET_PeerIdentity * const *get_path, const struct GNUNET_PeerIdentity * const *put_path, enum GNUNET_BLOCK_Type type, size_t size, const void *data); /** * Perform an asynchronous GET operation on the DHT identified. See * also "GNUNET_BLOCK_evaluate". * * @param handle handle to the DHT service * @param timeout how long to wait for transmission of this request to the service * @param type expected type of the response object * @param key the key to look up * @param desired_replication_level estimate of how many nearest peers this request should reach * @param options routing options for this message * @param bf bloom filter associated with query (can be NULL) * @param bf_mutator mutation value for bf * @param xquery extended query data (can be NULL, depending on type) * @param xquery_size number of bytes in xquery * @param iter function to call on each result * @param iter_cls closure for iter * * @return handle to stop the async get */ struct GNUNET_DHT_GetHandle * GNUNET_DHT_get_start (struct GNUNET_DHT_Handle *handle, struct GNUNET_TIME_Relative timeout, enum GNUNET_BLOCK_Type type, const GNUNET_HashCode * key, uint32_t desired_replication_level, enum GNUNET_DHT_RouteOption options, const struct GNUNET_CONTAINER_BloomFilter *bf, int32_t bf_mutator, const void *xquery, size_t xquery_size, GNUNET_DHT_GetIterator iter, void *iter_cls); /** * Stop async DHT-get. Frees associated resources. * * @param get_handle GET operation to stop. * * On return get_handle will no longer be valid, caller * must not use again!!! */ void GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle); /* ******** Special high-level API for finding peers *********** */ /** * Iterator called on each result obtained from a find peer * operation * * @param cls closure * @param peer hello of a target (peer near key) */ typedef void (*GNUNET_DHT_FindPeerProcessor)(void *cls, const struct GNUNET_HELLO_Message *peer); /** * Perform an asynchronous FIND PEER operation on the DHT. * * @param handle handle to the DHT service * @param timeout timeout for this request to be sent to the * service * @param key the key to look up * @param options routing options for this message * @param proc function to call on each result * @param proc_cls closure for proc * @return handle to stop the async get, NULL on error */ struct GNUNET_DHT_FindPeerHandle * GNUNET_DHT_find_peer_start (struct GNUNET_DHT_Handle *handle, struct GNUNET_TIME_Relative timeout, const GNUNET_HashCode *key, enum GNUNET_DHT_RouteOption options, GNUNET_DHT_FindPeerProcessor proc, void *proc_cls); /** * Stop async find peer. Frees associated resources. * * @param find_peer_handle GET operation to stop. */ void GNUNET_DHT_find_peer_stop (struct GNUNET_DHT_FindPeerHandle *find_peer_handle); /* ***** Special low-level API providing generic routeing abstraction ***** */ /** * Iterator called on each result obtained from a generic route * operation * * @param cls closure * @param key key that was used * @param outgoing_path NULL-terminated array of pointers * to the peers on reverse outgoing * path (or NULL if not recorded) * to the peers on the PUT path (or NULL if not recorded) * @param reply response */ typedef void (*GNUNET_DHT_ReplyProcessor)(void *cls, const GNUNET_HashCode *key, const struct GNUNET_PeerIdentity * const *outgoing_path, const struct GNUNET_MessageHeader *reply); /** * Perform an asynchronous ROUTE_START operation on the DHT. * * @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 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 transmission to the service; only applies * if 'iter' is NULL * @param iter function to call on each result, NULL if no replies are expected * @param iter_cls closure for iter * @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); /** * Stop async route operation. Frees associated resources. * * @param route_handle operation to stop. */ void GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle); /* ***** Special API for controlling DHT routing maintenance ******* */ /** * 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 cont continuation to call when done (transmitting request to service) * @param cont_cls closure for cont * @param handle handle to the DHT service */ void GNUNET_DHT_find_peers (struct GNUNET_DHT_Handle *handle, GNUNET_SCHEDULER_Task cont, void *cont_cls); /* ***** Special API for testing robustness with malicious peers ******* */ #if HAVE_MALICIOUS /* Note that these functions are NOT considered to be part of the "official" API and hence are NOT subjected to library versioning; only developers testing GNUnet's robustness should have any use for them, applications should never use them. Applications must NOT define "HAVE_MALICIOUS" before including this header. */ /** * 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 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); /** * 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); #endif #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif #endif /* gnunet_dht_service.h */