/* This file is part of GNUnet (C) 2012 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 2, 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; * @author Christian Grothoff * * Other functions we might want: * - enumerate all known zones */ #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 zone revocation */ #define GNUNET_NAMESTORE_TYPE_REV 65540 /** * 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). * * @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 peer is the authority for this record; it must thus * not be deleted (other records can be deleted if we run * out of space). */ GNUNET_NAMESTORE_RF_AUTHORITY = 1, /** * 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 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. * FIXME: goofy API: sometimes 'data' is individually * 'malloc'ed, sometimes it points into some existing * data area (so sometimes this should be a 'void *', * sometimes a 'const void *'). This is unclean. */ const void *data; /** * Expiration time for the DNS record. Can be relative * or absolute, depending on 'flags'. */ 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; }; /** * Store an item in the namestore. If the item is already present, * the expiration time is updated to the max of the existing time and * the new time. This API is used when we cache signatures from other * authorities. * * @param h handle to the namestore * @param zone_key public key of the zone * @param name name that is being mapped (at most 255 characters long) * @param freshness when does the corresponding block in the DHT expire (until * when should we never do a DHT lookup for the same name again)? * @param rd_count number of entries in 'rd' array * @param rd array of records with data to store * @param signature signature for all the records in the zone under the given name * @param cont continuation to call when done * @param cont_cls closure for cont * @return handle to abort the request */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_record_put (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *zone_key, const char *name, struct GNUNET_TIME_Absolute freshness, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, const struct GNUNET_CRYPTO_RsaSignature *signature, GNUNET_NAMESTORE_ContinuationWithStatus cont, void *cont_cls); /** * Check if a signature is valid. This API is used by the GNS Block * to validate signatures received from the network. * * @param public_key public key of the zone * @param freshness time set for block expiration * @param name name that is being mapped (at most 255 characters long) * @param rd_count number of entries in 'rd' array * @param rd array of records with data to store * @param signature signature for all the records in the zone under the given name * @return GNUNET_OK if the signature is valid */ int GNUNET_NAMESTORE_verify_signature (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *public_key, const struct GNUNET_TIME_Absolute freshness, const char *name, unsigned int rd_count, const struct GNUNET_NAMESTORE_RecordData *rd, const struct GNUNET_CRYPTO_RsaSignature *signature); /** * Store an item in the namestore. If the item is already present, * the expiration time is updated to the max of the existing time and * the new time. This API is used by the authority of a zone. * FIXME: consider allowing to pass multiple records in one call! * * @param h handle to the namestore * @param pkey private key of the zone * @param name name that is being mapped (at most 255 characters long) * @param rd record data to store * @param cont continuation to call when done * @param cont_cls closure for cont * @return handle to abort the request */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_record_create (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_RsaPrivateKey *pkey, const char *name, const struct GNUNET_NAMESTORE_RecordData *rd, GNUNET_NAMESTORE_ContinuationWithStatus cont, void *cont_cls); /** * Explicitly remove some content from the database. The * "cont"inuation will be called with status "GNUNET_OK" if content * was removed, "GNUNET_NO" if no matching entry was found and * "GNUNET_SYSERR" on all other types of errors. * This API is used by the authority of a zone. * * @param h handle to the namestore * @param pkey private key of the zone * @param name name that is being mapped (at most 255 characters long) * @param rd record data, remove specific record, NULL to remove the name and all records * @param cont continuation to call when done * @param cont_cls closure for cont * @return handle to abort the request */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_record_remove (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_RsaPrivateKey *pkey, const char *name, 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 zone_key public key of the zone * @param freshness when does the corresponding block in the DHT expire (until * when should we never do a DHT lookup for the same name again)?; * GNUNET_TIME_UNIT_ZERO_ABS if there are no records of any type in the namestore, * or the expiration time of the block in the namestore (even if there are zero * records matching the desired record type) * @param name name that is being mapped (at most 255 characters long) * @param rd_count number of entries in 'rd' array * @param rd array of records with data to store * @param signature signature of the record block, NULL if signature is unavailable (i.e. * because the user queried for a particular record type only) */ typedef void (*GNUNET_NAMESTORE_RecordProcessor) (void *cls, const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *zone_key, struct GNUNET_TIME_Absolute freshness, const char *name, unsigned int rd_len, const struct GNUNET_NAMESTORE_RecordData *rd, const struct GNUNET_CRYPTO_RsaSignature *signature); /** * Get a result for a particular key from the namestore. The processor * will only be called once. When using this functions, relative expiration * times will be converted to absolute expiration times and a signature * will be created if we are the authority. The record data and signature * passed to 'proc' is thus always suitable for passing on to other peers * (if we are the authority). If the record type is NOT set to 'ANY' and * if we are NOT the authority, then non-matching records may be omitted * from the result and no valid signature can be created; in this case, * 'signature' will be NULL and the result cannot be given to other peers. * * @param h handle to the namestore * @param zone zone to look up a record from * @param name name to look up * @param record_type desired record type, 0 for all * @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 proc * @return a handle that can be used to * cancel */ struct GNUNET_NAMESTORE_QueueEntry * GNUNET_NAMESTORE_lookup_record (struct GNUNET_NAMESTORE_Handle *h, const struct GNUNET_CRYPTO_ShortHashCode *zone, const char *name, uint32_t record_type, GNUNET_NAMESTORE_RecordProcessor proc, void *proc_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 hash of public key of the zone to look up in, never NULL * @param value_zone hash of the 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 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_ShortHashCode *zone, const struct GNUNET_CRYPTO_ShortHashCode *value_zone, GNUNET_NAMESTORE_RecordProcessor proc, void *proc_cls); /** * Starts a new zone iteration (used to periodically PUT all of our * records into our DHT). "proc" will be called once immediately, and * then again after "GNUNET_NAMESTORE_zone_iterator_next" is invoked. * * By specifying a 'zone' of NULL and setting 'GNUNET_NAMESTORE_RF_AUTHORITY' * in 'must_have_flags', we can iterate over all records for which we are * the authority (the 'authority' flag will NOT be set in the returned * records anyway). * * The 'GNUNET_NAMESTORE_RF_RELATIVE_EXPIRATION' * bit in 'must_have_flags' has a special meaning: * * 0) If the bit is clear, all relative expriation times are converted to * absolute expiration times. This is useful for performing DHT PUT * operations (and zone transfers) of our zone. The generated signatures * will be valid for other peers. * 1) if it is set, it means that relative expiration times should be * preserved when returned (this is useful for the zone editor user * interface). No signatures will be created in this case, as * signatures must not cover records with relative expiration times. * * Note that not all queries against this interface are equally performant * as for some combinations no efficient index may exist. * * @param h handle to the namestore * @param zone zone to access, NULL for all zones * @param must_have_flags flags that must be set for the record to be returned * @param must_not_have_flags flags that must NOT be set for the record to be returned * @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 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_ShortHashCode *zone, enum GNUNET_NAMESTORE_RecordFlags must_have_flags, enum GNUNET_NAMESTORE_RecordFlags must_not_have_flags, GNUNET_NAMESTORE_RecordProcessor 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); /** * 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); /* 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 rd array * @param rd array of GNUNET_NAMESTORE_RecordData with 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 rd array * @param rd array of GNUNET_NAMESTORE_RecordData with rd_count elements * @param dest_size size of the destination array * @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 rd 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 'value' of a record to a string. * * @param type type of the record * @param data value in binary encoding * @param data_size number of bytes in 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 a 'value' of a record to the 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 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 typename name to convert * @return corresponding number, UINT32_MAX on error */ uint32_t GNUNET_NAMESTORE_typename_to_number (const char *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. * * @return GNUNET_YES if the record is expired, * GNUNET_NO if not */ int GNUNET_NAMESTORE_is_expired (const struct GNUNET_NAMESTORE_RecordData *rd); #if 0 /* keep Emacsens' auto-indent happy */ { #endif #ifdef __cplusplus } #endif /* end of gnunet_namestore_service.h */ #endif