X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Finclude%2Fgnunet_dht_service.h;h=d9bbccbdf6f23e7749994ea2816d8330a5be500f;hb=6e626937fd5133188d2bd06f280a1b889219eef2;hp=00d9851b9c0b21ca8754bf846fa62dd208764493;hpb=7b80cc15aaf3f61fb05635577fdd5258d5b8bb17;p=oweals%2Fgnunet.git diff --git a/src/include/gnunet_dht_service.h b/src/include/gnunet_dht_service.h index 00d9851b9..d9bbccbdf 100644 --- a/src/include/gnunet_dht_service.h +++ b/src/include/gnunet_dht_service.h @@ -1,27 +1,35 @@ /* This file is part of GNUnet - (C) 2004, 2005, 2006, 2008, 2009 Christian Grothoff (and other contributing authors) + Copyright (C) 2004-2013, 2016 GNUnet e.V. - 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 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 - General Public License for more details. + Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see . - 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. + SPDX-License-Identifier: AGPL3.0-or-later */ /** - * @file include/gnunet_dht_service.h - * @brief API to the DHT service * @author Christian Grothoff + * + * @file + * API to the DHT service + * + * @defgroup dht DHT service + * Distributed Hash Table + * + * @see [Documentation](https://gnunet.org/developer-handbook-dht) + * + * @{ */ #ifndef GNUNET_DHT_SERVICE_H @@ -41,14 +49,16 @@ extern "C" /** - * Connection to the DHT service. + * Default republication frequency for stored data in the DHT. */ -struct GNUNET_DHT_Handle; +#define GNUNET_DHT_DEFAULT_REPUBLISH_FREQUENCY GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 60) + + /** - * Handle to control a route operation. + * Connection to the DHT service. */ -struct GNUNET_DHT_RouteHandle; +struct GNUNET_DHT_Handle; /** * Handle to control a get operation. @@ -65,38 +75,51 @@ 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 - }; +{ + /** + * 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, + + /** + * This is a 'FIND-PEER' request, so approximate results are fine. + */ + GNUNET_DHT_RO_FIND_PEER = 4, + + /** + * Possible message option for query key randomization. + */ + GNUNET_DHT_RO_BART = 8, + + /** + * Flag given to monitors if this was the last hop for a GET/PUT. + */ + GNUNET_DHT_RO_LAST_HOP = 16 +}; /** * Initialize the connection with the DHT service. * - * @param sched scheduler to use * @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 (struct GNUNET_SCHEDULER_Handle *sched, - const struct GNUNET_CONFIGURATION_Handle *cfg, +GNUNET_DHT_connect (const struct GNUNET_CONFIGURATION_Handle *cfg, unsigned int ht_len); @@ -111,34 +134,57 @@ GNUNET_DHT_disconnect (struct GNUNET_DHT_Handle *handle); /* *************** Standard API: get and put ******************* */ + /** - * Perform a PUT operation on the DHT identified by 'table' storing - * a binding of 'key' to 'value'. The peer does not have to be part - * of the table (if so, we will attempt to locate a peer that is!) + * Opaque handle to cancel a PUT operation. + */ +struct GNUNET_DHT_PutHandle; + + +/** + * Perform a PUT operation storing data in the DHT. * * @param handle handle to DHT service - * @param key the key to store data under + * @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 size number of bytes in @a data; must be less than 64k * @param data the data to store - * @param exp desired expiration time for the data - * @param timeout when to abort if we fail to transmit the request - * for the PUT to the local DHT service + * @param exp desired expiration time for the value * @param cont continuation to call when done (transmitting request to service) - * @param cont_cls closure for cont + * You must not call #GNUNET_DHT_disconnect in this continuation + * @param cont_cls closure for @a cont + * @return handle to cancel the "PUT" operation, NULL on error + * (size too big) */ -void +struct GNUNET_DHT_PutHandle * GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle, - const GNUNET_HashCode * key, - enum GNUNET_DHT_RouteOption options, + const struct GNUNET_HashCode *key, + uint32_t desired_replication_level, + enum GNUNET_DHT_RouteOption options, enum GNUNET_BLOCK_Type type, size_t size, - const char *data, + const void *data, struct GNUNET_TIME_Absolute exp, - struct GNUNET_TIME_Relative timeout, - GNUNET_SCHEDULER_Task cont, - void *cont_cls); + GNUNET_SCHEDULER_TaskCallback cont, + void *cont_cls); + + +/** + * Cancels a DHT PUT operation. Note that the PUT request may still + * go out over the network (we can't stop that); However, if the PUT + * has not yet been sent to the service, cancelling the PUT will stop + * this from happening (but there is no way for the user of this API + * to tell if that is the case). The only use for this API is to + * prevent a later call to 'cont' from #GNUNET_DHT_put (i.e. because + * the system is shutting down). + * + * @param ph put operation to cancel ('cont' will no longer be called) + */ +void +GNUNET_DHT_put_cancel (struct GNUNET_DHT_PutHandle *ph); /** @@ -148,232 +194,200 @@ GNUNET_DHT_put (struct GNUNET_DHT_Handle *handle, * @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 get_path peers on reply path (or NULL if not recorded) + * [0] = datastore's first neighbor, [length - 1] = local peer + * @param get_path_length number of entries in @a get_path + * @param put_path peers on the PUT path (or NULL if not recorded) + * [0] = origin, [length - 1] = datastore + * @param put_path_length number of entries in @a put_path * @param type type of the result - * @param size number of bytes in data + * @param size number of bytes in @a 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); - +typedef void +(*GNUNET_DHT_GetIterator) (void *cls, + struct GNUNET_TIME_Absolute exp, + const struct GNUNET_HashCode *key, + const struct GNUNET_PeerIdentity *get_path, + unsigned int get_path_length, + const struct GNUNET_PeerIdentity *put_path, + unsigned int put_path_length, + enum GNUNET_BLOCK_Type type, + size_t size, + const void *data); /** - * Perform an asynchronous GET operation on the DHT. See - * also "GNUNET_BLOCK_evaluate". + * Perform an asynchronous GET operation on the DHT identified. See + * also #GNUNET_BLOCK_evaluate. * * @param handle handle to the DHT service - * @param timeout timeout for this request to be sent to the - * service (this is NOT a timeout for receiving responses) - * @param type expected type of the response object (GNUNET_BLOCK_TYPE_FS_*) + * @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 extrended query data (can be NULL, depending on type) - * @param xquery_size number of bytes in xquery + * @param xquery extended query data (can be NULL, depending on type) + * @param xquery_size number of bytes in @a xquery * @param iter function to call on each result - * @param iter_cls closure for iter - * @return handle to stop the async get, NULL on error + * @param iter_cls closure for @a 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, - enum GNUNET_DHT_RouteOption options, - const struct GNUNET_CONTAINER_BloomFilter *bf, - int32_t bf_mutator, - const void *xquery, - size_t xquery_size, + const struct GNUNET_HashCode *key, + uint32_t desired_replication_level, + enum GNUNET_DHT_RouteOption options, + const void *xquery, + size_t xquery_size, GNUNET_DHT_GetIterator iter, void *iter_cls); /** - * Stop async DHT-get. Frees associated resources. + * Tell the DHT not to return any of the following known results + * to this client. * - * @param get_handle GET operation to stop. + * @param get_handle get operation for which results should be filtered + * @param num_results number of results to be blocked that are + * provided in this call (size of the @a results array) + * @param results array of hash codes over the `data` of the results + * to be blocked */ 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); - +GNUNET_DHT_get_filter_known_results (struct GNUNET_DHT_GetHandle *get_handle, + unsigned int num_results, + const struct GNUNET_HashCode *results); /** - * Stop async find peer. Frees associated resources. + * Stop async DHT-get. Frees associated resources. * - * @param find_peer_handle GET operation to stop. + * @param get_handle GET operation to stop. */ void -GNUNET_DHT_find_peer_stop (struct GNUNET_DHT_FindPeerHandle *find_peer_handle); - +GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle); -/* ***** Special low-level API providing generic routeing abstraction ***** */ +/* *************** Extended API: monitor ******************* */ /** - * Iterator called on each result obtained from a generic route - * operation - * - * @param cls closure - * @param key key that was used - * @param reply response + * Handle to monitor requests */ -typedef void (*GNUNET_DHT_ReplyProcessor)(void *cls, - const GNUNET_HashCode *key, - const struct GNUNET_MessageHeader *reply); - +struct GNUNET_DHT_MonitorHandle; /** - * Perform an asynchronous ROUTE_START operation on the DHT. + * Callback called on each GET request going through 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" + * @param cls Closure. + * @param options Options, for instance RecordRoute, DemultiplexEverywhere. + * @param type The type of data in the request. + * @param hop_count Hop count so far. + * @param path_length number of entries in @a path (or 0 if not recorded). + * @param path peers on the GET path (or NULL if not recorded). + * @param desired_replication_level Desired replication level. + * @param key Key of the requested data. */ -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); - +typedef void +(*GNUNET_DHT_MonitorGetCB) (void *cls, + enum GNUNET_DHT_RouteOption options, + enum GNUNET_BLOCK_Type type, + uint32_t hop_count, + uint32_t desired_replication_level, + unsigned int path_length, + const struct GNUNET_PeerIdentity *path, + const struct GNUNET_HashCode *key); /** - * Stop async route operation. Frees associated resources. + * Callback called on each GET reply going through the DHT. * - * @param route_handle operation to stop. + * @param cls Closure. + * @param type The type of data in the result. + * @param get_path Peers on GET path (or NULL if not recorded). + * @param get_path_length number of entries in @a get_path. + * @param put_path peers on the PUT path (or NULL if not recorded). + * @param put_path_length number of entries in @a get_path. + * @param exp Expiration time of the data. + * @param key Key of the data. + * @param data Pointer to the result data. + * @param size Number of bytes in @a data. */ -void -GNUNET_DHT_route_stop (struct GNUNET_DHT_RouteHandle *route_handle); - - -/* ***** Special API for controlling DHT routing maintenance ******* */ +typedef void +(*GNUNET_DHT_MonitorGetRespCB) (void *cls, + enum GNUNET_BLOCK_Type type, + const struct GNUNET_PeerIdentity *get_path, + unsigned int get_path_length, + const struct GNUNET_PeerIdentity *put_path, + unsigned int put_path_length, + struct GNUNET_TIME_Absolute exp, + const struct GNUNET_HashCode *key, + const void *data, + size_t size); /** - * 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. + * Callback called on each PUT request going through the DHT. * - * @param cont continuation to call when done (transmitting request to service) - * @param cont_cls closure for cont - * @param handle handle to the DHT service + * @param cls Closure. + * @param options Options, for instance RecordRoute, DemultiplexEverywhere. + * @param type The type of data in the request. + * @param hop_count Hop count so far. + * @param path_length number of entries in @a path (or 0 if not recorded). + * @param path peers on the PUT path (or NULL if not recorded). + * @param desired_replication_level Desired replication level. + * @param exp Expiration time of the data. + * @param key Key under which data is to be stored. + * @param data Pointer to the data carried. + * @param size Number of bytes in @a data. */ -void -GNUNET_DHT_find_peers (struct GNUNET_DHT_Handle *handle, - GNUNET_SCHEDULER_Task cont, - void *cont_cls); +typedef void +(*GNUNET_DHT_MonitorPutCB) (void *cls, + enum GNUNET_DHT_RouteOption options, + enum GNUNET_BLOCK_Type type, + uint32_t hop_count, + uint32_t desired_replication_level, + unsigned int path_length, + const struct GNUNET_PeerIdentity *path, + struct GNUNET_TIME_Absolute exp, + const struct GNUNET_HashCode *key, + const void *data, + size_t size); -/* ***** 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 - */ -void -GNUNET_DHT_set_malicious_dropper (struct GNUNET_DHT_Handle *handle); /** - * Send a message to the DHT telling it to start issuing random PUT - * requests every 'frequency' milliseconds. + * Start monitoring the local DHT service. * - * @param handle handle to the DHT service - * @param frequency delay (in milliseconds) between sending malicious messages + * @param handle Handle to the DHT service. + * @param type Type of blocks that are of interest. + * @param key Key of data of interest, NULL for all. + * @param get_cb Callback to process monitored get messages. + * @param get_resp_cb Callback to process monitored get response messages. + * @param put_cb Callback to process monitored put messages. + * @param cb_cls Closure for callbacks + * @return Handle to stop monitoring. */ -void -GNUNET_DHT_set_malicious_putter (struct GNUNET_DHT_Handle *handle, - struct GNUNET_TIME_Relative frequency); +struct GNUNET_DHT_MonitorHandle * +GNUNET_DHT_monitor_start (struct GNUNET_DHT_Handle *handle, + enum GNUNET_BLOCK_Type type, + const struct GNUNET_HashCode *key, + GNUNET_DHT_MonitorGetCB get_cb, + GNUNET_DHT_MonitorGetRespCB get_resp_cb, + GNUNET_DHT_MonitorPutCB put_cb, + void *cb_cls); /** - * Send a message to the DHT telling it to start issuing random GET - * requests every 'frequency' milliseconds. + * Stop monitoring. + * On return handle will no longer be valid, caller must not use it anymore. * - * @param handle handle to the DHT service - * @param frequency delay between sending malicious messages + * @param handle The handle to the monitor request returned by + * #GNUNET_DHT_monitor_start(). */ -void -GNUNET_DHT_set_malicious_getter (struct GNUNET_DHT_Handle *handle, - struct GNUNET_TIME_Relative frequency); - +void +GNUNET_DHT_monitor_stop (struct GNUNET_DHT_MonitorHandle *handle); -#endif #if 0 /* keep Emacsens' auto-indent happy */ { @@ -382,6 +396,6 @@ GNUNET_DHT_set_malicious_getter (struct GNUNET_DHT_Handle *handle, } #endif - #endif -/* gnunet_dht_service.h */ + +/** @} */ /* end of group dht */