/* This file is part of GNUnet (C) 2012, 2013 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_namestore_service.h * @brief API that can be used to 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. * @author Christian Grothoff */ #ifndef GNUNET_NAMESTORE_SERVICE_H #define GNUNET_NAMESTORE_SERVICE_H #include "gnunet_util_lib.h" #include "gnunet_block_lib.h" #ifdef __cplusplus extern "C" { #if 0 /* keep Emacsens' auto-indent happy */ } #endif #endif /** * Record type indicating any record/'*' */ #define GNUNET_NAMESTORE_TYPE_ANY 0 /** * Record type for GNS zone transfer ("PKEY"). */ #define GNUNET_NAMESTORE_TYPE_PKEY 65536 /** * Record type for GNS zone transfer ("PSEU"). */ #define GNUNET_NAMESTORE_TYPE_PSEU 65537 /** * Record type for GNS legacy hostnames ("LEHO"). */ #define GNUNET_NAMESTORE_TYPE_LEHO 65538 /** * Record type for VPN resolution */ #define GNUNET_NAMESTORE_TYPE_VPN 65539 /** * Record type for delegation to DNS. */ #define GNUNET_NAMESTORE_TYPE_GNS2DNS 65540 /** * Record type for a social place. */ #define GNUNET_NAMESTORE_TYPE_PLACE 65541 /** * Record type for a phone (of CONVERSATION). */ #define GNUNET_NAMESTORE_TYPE_PHONE 65542 /** * 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; /** * Maximum size of a value that can be stored in the namestore. */ #define GNUNET_NAMESTORE_MAX_VALUE_SIZE (63 * 1024) /** * 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); /** * Flags that can be set for a record. */ enum GNUNET_NAMESTORE_RecordFlags { /** * No special options. */ GNUNET_NAMESTORE_RF_NONE = 0, /** * This is a private record of this peer and it should * thus not be handed out to other peers. */ GNUNET_NAMESTORE_RF_PRIVATE = 2, /** * This record was added automatically by the system * and is pending user confimation. */ GNUNET_NAMESTORE_RF_PENDING = 4, /** * This expiration time of the record is a relative * time (not an absolute time). */ GNUNET_NAMESTORE_RF_RELATIVE_EXPIRATION = 8, /** * This record should not be used unless all (other) records with an absolute * expiration time have expired. */ GNUNET_NAMESTORE_RF_SHADOW_RECORD = 16 /** * When comparing flags for record equality for removal, * which flags should must match (in addition to the type, * name, expiration value and data of the record)? All flags * that are not listed here will be ignored for this purpose. * (for example, we don't expect that users will remember to * pass the '--private' option when removing a record from * the namestore, hence we don't require this particular option * to match upon removal). See also * #GNUNET_NAMESTORE_records_cmp. */ #define GNUNET_NAMESTORE_RF_RCMP_FLAGS (GNUNET_NAMESTORE_RF_RELATIVE_EXPIRATION) }; /** * A GNS record. */ struct GNUNET_NAMESTORE_RecordData { /** * Binary value stored in the DNS record. Note: "data" must never * be individually 'malloc'ed, but instead always points into some * existing data area. */ const void *data; /** * Expiration time for the DNS record. Can be relative * or absolute, depending on 'flags'. Measured in the same * unit as GNUnet time (microseconds). */ uint64_t expiration_time; /** * Number of bytes in 'data'. */ size_t data_size; /** * Type of the GNS/DNS record. */ uint32_t record_type; /** * Flags for the record. */ enum GNUNET_NAMESTORE_RecordFlags flags; }; GNUNET_NETWORK_STRUCT_BEGIN /** * Information we have in an encrypted block with record data (i.e. in the DHT). */ struct GNUNET_NAMESTORE_Block { /** * Signature of the block. */ struct GNUNET_CRYPTO_EccSignature signature; /** * Derived key used for signing; hash of this is the query. */ struct GNUNET_CRYPTO_EccPublicSignKey derived_key; /** * Number of bytes signed; also specifies the number of bytes * of encrypted data that follow. */ struct GNUNET_CRYPTO_EccSignaturePurpose purpose; /** * Expiration time of the block. */ struct GNUNET_TIME_AbsoluteNBO expiration_time; /* followed by encrypted data */ }; GNUNET_NETWORK_STRUCT_END /** * Store an item in the namestore. If the item is already present, * it is replaced with the new record. * * @param h handle to the namestore * @param block block 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_block_cache (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_NAMESTORE_Block *block, GNUNET_NAMESTORE_ContinuationWithStatus cont, void *cont_cls); /** * 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. * * @param h handle to the namestore * @param pkey private key of the zone * @param label name that is being mapped (at most 255 characters long) * @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_EccPrivateKey *pkey, const char *label, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, GNUNET_NAMESTORE_ContinuationWithStatus cont, void *cont_cls); /** * Process a record that was stored in the namestore. * * @param cls closure * @param block block that was stored in the namestore */ typedef void (*GNUNET_NAMESTORE_BlockProcessor) (void *cls, const struct GNUNET_NAMESTORE_Block *block); /** * Get a result for a particular key from the namestore. The processor * will only be called once. * * @param h handle to the namestore * @param derived_hash hash of zone key combined with name to lookup * then at the end once with NULL * @param proc function to call on the matching block, or with * NULL if there is no matching block * @param proc_cls closure for @a proc * @return a handle that can be used to cancel */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_lookup_block (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_HashCode *derived_hash, GNUNET_NAMESTORE_BlockProcessor proc, void *proc_cls); /** * Process a record that was stored in the namestore. * * @param cls closure * @param zone private key of the zone; NULL on disconnect * @param label label of the records; NULL on disconnect * @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_EccPrivateKey *zone, const char *label, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd); /** * 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 public key of the zone to look up in, never NULL * @param value_zone public key of the target zone (value), never NULL * @param proc function to call on the matching records, or with * NULL (rd_count == 0) if there are no matching records * @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_EccPrivateKey *zone, const struct GNUNET_CRYPTO_EccPublicSignKey *value_zone, GNUNET_NAMESTORE_RecordMonitor proc, void *proc_cls); /** * Process a records that were decrypted from a block. * * @param cls closure * @param rd_count number of entries in @a rd array * @param rd array of records with data to store */ typedef void (*GNUNET_NAMESTORE_RecordCallback) (void *cls, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd); /** * 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. * * @param h handle to the namestore * @param zone zone to access, NULL for all zones * @param proc function to call on each name from the zone; it * will be called repeatedly with a value (if available) * and always once at the end with a name of NULL. * @param proc_cls closure for @a proc * @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_EccPrivateKey *zone, GNUNET_NAMESTORE_RecordMonitor proc, void *proc_cls); /** * Calls the record processor specified in #GNUNET_NAMESTORE_zone_iteration_start * for the next record. * * @param it the iterator */ void GNUNET_NAMESTORE_zone_iterator_next (struct GNUNET_NAMESTORE_ZoneIterator *it); /** * 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; /** * Function called once the monitor has caught up with the current * state of the database. Will be called AGAIN after each disconnect * (record monitor called with 'NULL' for zone_key) once we're again * in sync. * * @param cls closure */ typedef void (*GNUNET_NAMESTORE_RecordsSynchronizedCallback)(void *cls); /** * Begin monitoring a zone for changes. Will first call the @a monitor function * on all existing records in the selected zone(s), then calls @a sync_cb, * and then calls the @a monitor whenever a record changes. If the namestore * disconnects, the @a monitor function is called with a disconnect event; if * the connection is re-established, the process begins from the start (all * existing records, sync, then updates). * * @param cfg configuration to use to connect to namestore * @param zone zone to monitor * @param monitor function to call on zone changes * @param sync_cb function called when we're in sync with the namestore * @param cls closure for @a monitor and @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_EccPrivateKey *zone, GNUNET_NAMESTORE_RecordMonitor monitor, GNUNET_NAMESTORE_RecordsSynchronizedCallback sync_cb, void *cls); /** * 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); /* convenience APIs for serializing / deserializing GNS records */ /** * Calculate how many bytes we will need to serialize the given * records. * * @param rd_count number of records in the @a rd array * @param rd array of #GNUNET_NAMESTORE_RecordData with @a rd_count elements * @return the required size to serialize */ size_t GNUNET_NAMESTORE_records_get_size (unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd); /** * Serialize the given records to the given destination buffer. * * @param rd_count number of records in the @a rd array * @param rd array of #GNUNET_NAMESTORE_RecordData with @a rd_count elements * @param dest_size size of the destination array @a dst * @param dest where to write the result * @return the size of serialized records, -1 if records do not fit */ ssize_t GNUNET_NAMESTORE_records_serialize (unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, size_t dest_size, char *dest); /** * Deserialize the given records to the given destination. * * @param len size of the serialized record data * @param src the serialized record data * @param rd_count number of records in the @a dest array * @param dest where to put the data * @return #GNUNET_OK on success, #GNUNET_SYSERR on error */ int GNUNET_NAMESTORE_records_deserialize (size_t len, const char *src, unsigned int rd_count, struct GNUNET_NAMESTORE_RecordData *dest); /** * Convert the binary value @a data of a record of * type @a type to a human-readable string. * * @param type type of the record * @param data value in binary encoding * @param data_size number of bytes in @a data * @return NULL on error, otherwise human-readable representation of the value */ char * GNUNET_NAMESTORE_value_to_string (uint32_t type, const void *data, size_t data_size); /** * Convert human-readable version of the value @a s of a record * of type @a type to the respective binary representation. * * @param type type of the record * @param s human-readable string * @param data set to value in binary encoding (will be allocated) * @param data_size set to number of bytes in @a data * @return #GNUNET_OK on success */ int GNUNET_NAMESTORE_string_to_value (uint32_t type, const char *s, void **data, size_t *data_size); /** * Convert a type name (i.e. "AAAA") to the corresponding number. * * @param dns_typename name to convert * @return corresponding number, UINT32_MAX on error */ uint32_t GNUNET_NAMESTORE_typename_to_number (const char *dns_typename); /** * Convert a type number (i.e. 1) to the corresponding type string (i.e. "A") * * @param type number of a type to convert * @return corresponding typestring, NULL on error */ const char * GNUNET_NAMESTORE_number_to_typename (uint32_t type); /** * Test if a given record is expired. * * @param rd record to test * @return #GNUNET_YES if the record is expired, * #GNUNET_NO if not */ int GNUNET_NAMESTORE_is_expired (const struct GNUNET_NAMESTORE_RecordData *rd); /** * Convert a UTF-8 string to UTF-8 lowercase * @param src source string * @return converted result */ char * GNUNET_NAMESTORE_normalize_string (const char *src); /** * Convert a zone to a string (for printing debug messages). * This is one of the very few calls in the entire API that is * NOT reentrant! * * @param z public key of a zone * @return string form; will be overwritten by next call to #GNUNET_NAMESTORE_z2s. */ const char * GNUNET_NAMESTORE_z2s (const struct GNUNET_CRYPTO_EccPublicSignKey *z); /** * Convert public key to the respective absolute domain name in the * ".zkey" pTLD. * This is one of the very few calls in the entire API that is * NOT reentrant! * * @param pkey a public key with a point on the eliptic curve * @return string "X.zkey" where X is the coordinates of the public * key in an encoding suitable for DNS labels. */ const char * GNUNET_NAMESTORE_pkey_to_zkey (const struct GNUNET_CRYPTO_EccPublicSignKey *pkey); /** * Convert an absolute domain name in the ".zkey" pTLD to the * respective public key. * * @param zkey string "X.zkey" where X is the public * key in an encoding suitable for DNS labels. * @param pkey set to a public key on the eliptic curve * @return #GNUNET_SYSERR if @a zkey has the wrong syntax */ int GNUNET_NAMESTORE_zkey_to_pkey (const char *zkey, struct GNUNET_CRYPTO_EccPublicSignKey *pkey); /** * Calculate the DHT query for a given @a label in a given @a zone. * * @param zone private key of the zone * @param label label of the record * @param query hash to use for the query */ void GNUNET_NAMESTORE_query_from_private_key (const struct GNUNET_CRYPTO_EccPrivateKey *zone, const char *label, struct GNUNET_HashCode *query); /** * Calculate the DHT query for a given @a label in a given @a zone. * * @param pub public key of the zone * @param label label of the record * @param query hash to use for the query */ void GNUNET_NAMESTORE_query_from_public_key (const struct GNUNET_CRYPTO_EccPublicSignKey *pub, const char *label, struct GNUNET_HashCode *query); /** * Sign name and records * * @param key the private key * @param expire block expiration * @param label the name for the records * @param rd record data * @param rd_count number of records in @a rd */ struct GNUNET_NAMESTORE_Block * GNUNET_NAMESTORE_block_create (const struct GNUNET_CRYPTO_EccPrivateKey *key, struct GNUNET_TIME_Absolute expire, const char *label, const struct GNUNET_NAMESTORE_RecordData *rd, unsigned int rd_count); /** * Check if a signature is valid. This API is used by the GNS Block * to validate signatures received from the network. * * @param block block to verify * @return #GNUNET_OK if the signature is valid */ int GNUNET_NAMESTORE_block_verify (const struct GNUNET_NAMESTORE_Block *block); /** * Decrypt block. * * @param block block to decrypt * @param zone_key public key of the zone * @param label the name for the records * @param proc function to call with the result * @param proc_cls closure for @a proc * @return #GNUNET_OK on success, #GNUNET_SYSERR if the block was * not well-formed */ int GNUNET_NAMESTORE_block_decrypt (const struct GNUNET_NAMESTORE_Block *block, const struct GNUNET_CRYPTO_EccPublicSignKey *zone_key, const char *label, GNUNET_NAMESTORE_RecordCallback proc, void *proc_cls); /** * Compares if two records are equal * * @param a a record * @param b another record * @return #GNUNET_YES if the records are equal, or #GNUNET_NO if not. */ int GNUNET_NAMESTORE_records_cmp (const struct GNUNET_NAMESTORE_RecordData *a, const struct GNUNET_NAMESTORE_RecordData *b); /** * Returns the expiration time of the given block of records. The block * expiration time is the expiration time of the record with smallest * expiration time. * * @param rd_count number of records given in @a rd * @param rd array of records * @return absolute expiration time */ struct GNUNET_TIME_Absolute GNUNET_NAMESTORE_record_get_expiration_time (unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif /* end of gnunet_namestore_service.h */ #endif