/* This file is part of GNUnet Copyright (C) 2012, 2013, 2018 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. You should have received a copy of the GNU Affero General Public License along with this program. If not, see . SPDX-License-Identifier: AGPL3.0-or-later */ /** * @author Christian Grothoff * * @file * API that can be used to store naming information on a GNUnet node; * * @defgroup namestore Name Store service * Store naming information on a GNUnet node. * * Naming information can either be records for which this peer/user is * authoritative, or blocks which are cached, encrypted naming data from other * peers. * * @see [Documentation](https://gnunet.org/namestore-subsystem) * * @{ */ #ifndef GNUNET_NAMESTORE_SERVICE_H #define GNUNET_NAMESTORE_SERVICE_H #include "gnunet_util_lib.h" #include "gnunet_block_lib.h" #include "gnunet_gnsrecord_lib.h" #ifdef __cplusplus extern "C" { #if 0 /* keep Emacsens' auto-indent happy */ } #endif #endif /** * Entry in the queue. */ struct GNUNET_NAMESTORE_QueueEntry; /** * Handle to the namestore service. */ struct GNUNET_NAMESTORE_Handle; /** * Handle to the namestore zone iterator. */ struct GNUNET_NAMESTORE_ZoneIterator; /** * Connect to the namestore service. * * @param cfg configuration to use * @return handle to use to access the service */ struct GNUNET_NAMESTORE_Handle * GNUNET_NAMESTORE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg); /** * Disconnect from the namestore service (and free associated * resources). Must not be called from within operation callbacks of * the API. * * @param h handle to the namestore */ void GNUNET_NAMESTORE_disconnect (struct GNUNET_NAMESTORE_Handle *h); /** * Continuation called to notify client about result of the * operation. * * @param cls closure * @param success #GNUNET_SYSERR on failure (including timeout/queue drop/failure to validate) * #GNUNET_NO if content was already there or not found * #GNUNET_YES (or other positive value) on success * @param emsg NULL on success, otherwise an error message */ typedef void (*GNUNET_NAMESTORE_ContinuationWithStatus) (void *cls, int32_t success, const char *emsg); /** * Store an item in the namestore. If the item is already present, * it is replaced with the new record. Use an empty array to * remove all records under the given name. * * The continuation is called after the value has been stored in the * database. Monitors may be notified asynchronously (basically with * a buffer). However, if any monitor is consistently too slow to * keep up with the changes, calling @a cont will be delayed until the * monitors do keep up. * * @param h handle to the namestore * @param pkey private key of the zone * @param label name that is being mapped * @param rd_count number of records in the 'rd' array * @param rd array of records with data to store * @param cont continuation to call when done * @param cont_cls closure for @a cont * @return handle to abort the request */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_records_store (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_EcdsaPrivateKey *pkey, const char *label, unsigned int rd_count, const struct GNUNET_GNSRECORD_Data *rd, GNUNET_NAMESTORE_ContinuationWithStatus cont, void *cont_cls); /** * Process a record that was stored in the namestore. * * @param cls closure * @param zone private key of the zone * @param label label of the records * @param rd_count number of entries in @a rd array, 0 if label was deleted * @param rd array of records with data to store */ typedef void (*GNUNET_NAMESTORE_RecordMonitor) (void *cls, const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone, const char *label, unsigned int rd_count, const struct GNUNET_GNSRECORD_Data *rd); /** * Set the desired nick name for a zone * * @param h handle to the namestore * @param pkey private key of the zone * @param nick the nick name to set * @param cont continuation to call when done * @param cont_cls closure for @a cont * @return handle to abort the request */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_set_nick (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_EcdsaPrivateKey *pkey, const char *nick, GNUNET_NAMESTORE_ContinuationWithStatus cont, void *cont_cls); /** * Lookup an item in the namestore. * * @param h handle to the namestore * @param pkey private key of the zone * @param label name that is being mapped * @param error_cb function to call on error (i.e. disconnect) * the handle is afterwards invalid * @param error_cb_cls closure for @a error_cb * @param rm function to call with the result (with 0 records if we don't have that label); * the handle is afterwards invalid * @param rm_cls closure for @a rm * @return handle to abort the request */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_records_lookup (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_EcdsaPrivateKey *pkey, const char *label, GNUNET_SCHEDULER_TaskCallback error_cb, void *error_cb_cls, GNUNET_NAMESTORE_RecordMonitor rm, void *rm_cls); /** * Look for an existing PKEY delegation record for a given public key. * Returns at most one result to the processor. * * @param h handle to the namestore * @param zone private key of the zone to look up in, never NULL * @param value_zone public key of the target zone (value), never NULL * @param error_cb function to call on error (i.e. disconnect) * the handle is afterwards invalid * @param error_cb_cls closure for @a error_cb * @param proc function to call on the matching records, or with * NULL (rd_count == 0) if there are no matching records; * the handle is afterwards invalid * @param proc_cls closure for @a proc * @return a handle that can be used to * cancel */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_zone_to_name (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone, const struct GNUNET_CRYPTO_EcdsaPublicKey *value_zone, GNUNET_SCHEDULER_TaskCallback error_cb, void *error_cb_cls, GNUNET_NAMESTORE_RecordMonitor proc, void *proc_cls); /** * Cancel a namestore operation. The final callback from the * operation must not have been done yet. Must be called on any * namestore operation that has not yet completed prior to calling * #GNUNET_NAMESTORE_disconnect. * * @param qe operation to cancel */ void GNUNET_NAMESTORE_cancel (struct GNUNET_NAMESTORE_QueueEntry *qe); /** * Starts a new zone iteration (used to periodically PUT all of our * records into our DHT). This MUST lock the `struct GNUNET_NAMESTORE_Handle` * for any other calls than #GNUNET_NAMESTORE_zone_iterator_next() and * #GNUNET_NAMESTORE_zone_iteration_stop. @a proc will be called once * immediately, and then again after * #GNUNET_NAMESTORE_zone_iterator_next() is invoked. * * On error (disconnect), @a error_cb will be invoked. * On normal completion, @a finish_cb proc will be * invoked. * * @param h handle to the namestore * @param zone zone to access, NULL for all zones * @param error_cb function to call on error (i.e. disconnect), * the handle is afterwards invalid * @param error_cb_cls closure for @a error_cb * @param proc function to call on each name from the zone; it * will be called repeatedly with a value (if available) * @param proc_cls closure for @a proc * @param finish_cb function to call on completion * the handle is afterwards invalid * @param finish_cb_cls closure for @a finish_cb * @return an iterator handle to use for iteration */ struct GNUNET_NAMESTORE_ZoneIterator * GNUNET_NAMESTORE_zone_iteration_start (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone, GNUNET_SCHEDULER_TaskCallback error_cb, void *error_cb_cls, GNUNET_NAMESTORE_RecordMonitor proc, void *proc_cls, GNUNET_SCHEDULER_TaskCallback finish_cb, void *finish_cb_cls); /** * Calls the record processor specified in #GNUNET_NAMESTORE_zone_iteration_start * for the next record. * * @param it the iterator * @param limit number of records to return to the iterator in one shot * (before #GNUNET_NAMESTORE_zone_iterator_next is to be called again) */ void GNUNET_NAMESTORE_zone_iterator_next (struct GNUNET_NAMESTORE_ZoneIterator *it, uint64_t limit); /** * Stops iteration and releases the namestore handle for further calls. Must * be called on any iteration that has not yet completed prior to calling * #GNUNET_NAMESTORE_disconnect. * * @param it the iterator */ void GNUNET_NAMESTORE_zone_iteration_stop (struct GNUNET_NAMESTORE_ZoneIterator *it); /** * Handle for a monitoring activity. */ struct GNUNET_NAMESTORE_ZoneMonitor; /** * Begin monitoring a zone for changes. Will first call the @a * monitor function on all existing records in the selected zone(s) if * @a iterate_first is #GNUNET_YES. In any case, we will then call @a * sync_cb, and then afterwards call the @a monitor whenever a record * changes. If the namestore disconnects, the @a error_cb function is * called with a disconnect event. Once the connection is * re-established, the process begins from the start (depending on @a * iterate_first, we will again first do all existing records, then @a * sync, then updates). * * @param cfg configuration to use to connect to namestore * @param zone zone to monitor, NULL for all zones * @param iterate_first #GNUNET_YES to first iterate over all existing records, * #GNUNET_NO to only return changes that happen from now on * @param error_cb function to call on error (i.e. disconnect); note that * unlike the other error callbacks in this API, a call to this * function does NOT destroy the monitor handle, it merely signals * that monitoring is down. You need to still explicitly call * #GNUNET_NAMESTORE_zone_monitor_stop(). * @param error_cb_cls closure for @a error_cb * @param monitor function to call on zone changes, with an initial limit of 1 * @param monitor_cls closure for @a monitor * @param sync_cb function called when we're in sync with the namestore * @param sync_cb_cls closure for @a sync_cb * @return handle to stop monitoring */ struct GNUNET_NAMESTORE_ZoneMonitor * GNUNET_NAMESTORE_zone_monitor_start (const struct GNUNET_CONFIGURATION_Handle *cfg, const struct GNUNET_CRYPTO_EcdsaPrivateKey *zone, int iterate_first, GNUNET_SCHEDULER_TaskCallback error_cb, void *error_cb_cls, GNUNET_NAMESTORE_RecordMonitor monitor, void *monitor_cls, GNUNET_SCHEDULER_TaskCallback sync_cb, void *sync_cb_cls); /** * Calls the monitor processor specified in #GNUNET_NAMESTORE_zone_monitor_start * for the next record(s). This function is used to allow clients that merely * monitor the NAMESTORE to still throttle namestore operations, so we can be * sure that the monitors can keep up. * * Note that #GNUNET_NAMESTORE_records_store() only waits for this * call if the previous limit set by the client was already reached. * Thus, by using a @a limit greater than 1, monitors basically enable * a queue of notifications to be processed asynchronously with some * delay. Note that even with a limit of 1 the * #GNUNET_NAMESTORE_records_store() function will run asynchronously * and the continuation may be invoked before the monitors completed * (or even started) processing the notification. Thus, monitors will * only closely track the current state of the namestore, but not * be involved in the transactions. * * @param zm the monitor * @param limit number of records to return to the iterator in one shot * (before #GNUNET_NAMESTORE_zone_monitor_next is to be called again) */ void GNUNET_NAMESTORE_zone_monitor_next (struct GNUNET_NAMESTORE_ZoneMonitor *zm, uint64_t limit); /** * Stop monitoring a zone for changes. * * @param zm handle to the monitor activity to stop */ void GNUNET_NAMESTORE_zone_monitor_stop (struct GNUNET_NAMESTORE_ZoneMonitor *zm); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif #endif /** @} */ /* end of group */