/*
This file is part of GNUnet
- (C) 2004, 2005, 2006, 2008, 2009 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2004-2013 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
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
- * @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
/**
- * FIXME: document.
+ * Default republication frequency for stored data in the DHT.
*/
#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.
*/
* 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
+};
/**
/* *************** Standard API: get and put ******************* */
+
+/**
+ * Opaque handle to cancel a PUT operation.
+ */
+struct GNUNET_DHT_PutHandle;
+
+
+/**
+ * Type of a PUT continuation. You must not call
+ * #GNUNET_DHT_disconnect in this continuation.
+ *
+ * @param cls closure
+ * @param success #GNUNET_OK if the PUT was transmitted,
+ * #GNUNET_NO on timeout,
+ * #GNUNET_SYSERR on disconnect from service
+ * after the PUT message was transmitted
+ * (so we don't know if it was received or not)
+ */
+typedef void (*GNUNET_DHT_PutContinuation)(void *cls,
+ int success);
+
+
/**
* Perform a PUT operation storing data in the DHT.
*
* 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 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
+ * 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,
+ 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,
+ size_t size, const void *data,
struct GNUNET_TIME_Absolute exp,
struct GNUNET_TIME_Relative timeout,
- GNUNET_SCHEDULER_Task cont,
+ GNUNET_DHT_PutContinuation 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);
+
+
/**
* 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 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 identified. See
- * also "GNUNET_BLOCK_evaluate".
+ * 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 xquery_size number of bytes in @a xquery
* @param iter function to call on each result
- * @param iter_cls closure for iter
+ * @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,
+ const struct 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);
+ const void *xquery, size_t xquery_size,
+ GNUNET_DHT_GetIterator iter, void *iter_cls);
+/**
+ * Tell the DHT not to return any of the following known results
+ * to this client.
+ *
+ * @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_filter_known_results (struct GNUNET_DHT_GetHandle *get_handle,
+ unsigned int num_results,
+ const struct GNUNET_HashCode *results);
+
/**
* Stop async DHT-get. Frees associated resources.
*
GNUNET_DHT_get_stop (struct GNUNET_DHT_GetHandle *get_handle);
-/* ******** Special high-level API for finding peers *********** */
+/* *************** Extended API: monitor ******************* */
/**
- * Iterator called on each result obtained from a find peer
- * operation
- *
- * @param cls closure
- * @param peer hello of a target (peer near key)
+ * Handle to monitor requests
*/
-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);
-
+struct GNUNET_DHT_MonitorHandle;
/**
- * Stop async find peer. Frees associated resources.
+ * Callback called on each GET request going through the DHT.
*
- * @param find_peer_handle GET operation to stop.
+ * @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.
*/
-void
-GNUNET_DHT_find_peer_stop (struct GNUNET_DHT_FindPeerHandle *find_peer_handle);
-
-
-
-/* ***** Special low-level API providing generic routeing abstraction ***** */
+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);
/**
- * Iterator called on each result obtained from a generic route
- * operation
+ * Callback called on each GET reply going through the DHT.
*
- * @param cls closure
- * @param key key that was used
- * @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 reply response
+ * @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.
*/
-typedef void (*GNUNET_DHT_ReplyProcessor)(void *cls,
- const GNUNET_HashCode *key,
- const struct GNUNET_PeerIdentity * const *get_path,
- const struct GNUNET_PeerIdentity * const *put_path,
- const struct GNUNET_MessageHeader *reply);
-
+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);
/**
- * Perform an asynchronous ROUTE_START operation on the DHT.
+ * Callback called on each PUT 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 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 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_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);
/**
- * Stop async route operation. Frees associated resources.
+ * Start monitoring the local DHT service.
*
- * @param route_handle operation to stop.
+ * @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_route_stop (struct GNUNET_DHT_RouteHandle *route_handle);
-
-
-/* ***** Special API for controlling DHT routing maintenance ******* */
+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 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.
+ * Stop monitoring.
+ * On return handle will no longer be valid, caller must not use again!!!
*
- * @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 handle The handle to the monitor request returned by monitor_start.
*/
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
- */
-void
-GNUNET_DHT_set_malicious_dropper (struct GNUNET_DHT_Handle *handle);
+GNUNET_DHT_monitor_stop (struct GNUNET_DHT_MonitorHandle *handle);
+#if ENABLE_MALICIOUS
/**
- * Send a message to the DHT telling it to start issuing random PUT
- * requests every 'frequency' milliseconds.
+ * Type of a Malicious continuation. You must not call
+ * #GNUNET_DHT_disconnect in this continuation.
*
- * @param handle handle to the DHT service
- * @param frequency delay (in milliseconds) between sending malicious messages
+ * @param cls closure
+ * @param success #GNUNET_OK if the set malicious request was transmitted,
+ * #GNUNET_NO on timeout,
+ * #GNUNET_SYSERR on disconnect from service
+ * after the PUT message was transmitted
+ * (so we don't know if it was received or not)
*/
-void
-GNUNET_DHT_set_malicious_putter (struct GNUNET_DHT_Handle *handle,
- struct GNUNET_TIME_Relative frequency);
-
+typedef void (*GNUNET_DHT_ActMaliciousContinuation)(void *cls,
+ int success);
/**
- * Send a message to the DHT telling it to start issuing random GET
- * requests every 'frequency' milliseconds.
+ * Turn the DHT service to act malicious
*
- * @param handle handle to the DHT service
- * @param frequency delay between sending malicious messages
+ * @param handle the DHT handle
+ * @param action 1 to make the service malicious; 0 to make it benign
+ FIXME: perhaps make this an enum of known malicious behaviors?
*/
-void
-GNUNET_DHT_set_malicious_getter (struct GNUNET_DHT_Handle *handle,
- struct GNUNET_TIME_Relative frequency);
-
-
+struct GNUNET_DHT_ActMaliciousHandle *
+GNUNET_DHT_act_malicious (struct GNUNET_DHT_Handle *handle,
+ unsigned int action,
+ GNUNET_DHT_PutContinuation cont,
+ void *cont_cls);
#endif
+
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
}
#endif
-
#endif
-/* gnunet_dht_service.h */
+
+/** @} */ /* end of group dht */
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