/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#ifndef DNS_JOURNAL_H
#define DNS_JOURNAL_H 1
/*****
***** Module Info
*****/
/*! \file dns/journal.h
* \brief
* Database journaling.
*/
/***
*** Imports
***/
#include <inttypes.h>
#include <stdbool.h>
#include <isc/lang.h>
#include <isc/magic.h>
#include <dns/diff.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/types.h>
/***
*** Defines.
***/
#define DNS_JOURNALOPT_RESIGN 0x00000001
#define DNS_JOURNAL_READ 0x00000000 /* false */
#define DNS_JOURNAL_CREATE 0x00000001 /* true */
#define DNS_JOURNAL_WRITE 0x00000002
#define DNS_JOURNAL_SIZE_MAX INT32_MAX
#define DNS_JOURNAL_SIZE_MIN 4096
/*% Print transaction header data */
#define DNS_JOURNAL_PRINTXHDR 0x0001
/*% Rewrite whole journal file instead of compacting */
#define DNS_JOURNAL_COMPACTALL 0x0001
#define DNS_JOURNAL_VERSION1 0x0002
/***
*** Types
***/
/*%
* A dns_journal_t represents an open journal file. This is an opaque type.
*
* A particular dns_journal_t object may be opened for writing, in which case
* it can be used for writing transactions to a journal file, or it can be
* opened for reading, in which case it can be used for reading transactions
* from (iterating over) a journal file. A single dns_journal_t object may
* not be used for both purposes.
*/
typedef struct dns_journal dns_journal_t;
/***
*** Functions
***/
ISC_LANG_BEGINDECLS
/**************************************************************************/
isc_result_t
dns_db_createsoatuple(dns_db_t *db, dns_dbversion_t *ver, isc_mem_t *mctx,
dns_diffop_t op, dns_difftuple_t **tp);
/*!< brief
* Create a diff tuple for the current database SOA.
* XXX this probably belongs somewhere else.
*/
/*@{*/
#define DNS_SERIAL_GT(a, b) ((int)(((a) - (b)) & 0xFFFFFFFF) > 0)
#define DNS_SERIAL_GE(a, b) ((int)(((a) - (b)) & 0xFFFFFFFF) >= 0)
/*!< brief
* Compare SOA serial numbers. DNS_SERIAL_GT(a, b) returns true iff
* a is "greater than" b where "greater than" is as defined in RFC1982.
* DNS_SERIAL_GE(a, b) returns true iff a is "greater than or equal to" b.
*/
/*@}*/
/**************************************************************************/
/*
* Journal object creation and destruction.
*/
isc_result_t
dns_journal_open(isc_mem_t *mctx, const char *filename, unsigned int mode,
dns_journal_t **journalp);
/*%<
* Open the journal file 'filename' and create a dns_journal_t object for it.
*
* DNS_JOURNAL_CREATE open the journal for reading and writing and create
* the journal if it does not exist.
* DNS_JOURNAL_WRITE open the journal for reading and writing.
* DNS_JOURNAL_READ open the journal for reading only.
*/
void
dns_journal_destroy(dns_journal_t **journalp);
/*%<
* Destroy a dns_journal_t, closing any open files and freeing its memory.
*/
/**************************************************************************/
/*
* Writing transactions to journals.
*/
isc_result_t
dns_journal_begin_transaction(dns_journal_t *j);
/*%<
* Prepare to write a new transaction to the open journal file 'j'.
*
* Requires:
* \li 'j' is open for writing.
*/
isc_result_t
dns_journal_writediff(dns_journal_t *j, dns_diff_t *diff);
/*%<
* Write 'diff' to the current transaction of journal file 'j'.
*
* Requires:
* \li 'j' is open for writing and dns_journal_begin_transaction()
* has been called.
*
*\li 'diff' is a full or partial, correctly ordered IXFR
* difference sequence.
*/
isc_result_t
dns_journal_commit(dns_journal_t *j);
/*%<
* Commit the current transaction of journal file 'j'.
*
* Requires:
* \li 'j' is open for writing and dns_journal_begin_transaction()
* has been called.
*
* \li dns_journal_writediff() has been called one or more times
* to form a complete, correctly ordered IXFR difference
* sequence.
*/
isc_result_t
dns_journal_write_transaction(dns_journal_t *j, dns_diff_t *diff);
/*%
* Write a complete transaction at once to a journal file,
* sorting it if necessary, and commit it. Equivalent to calling
* dns_diff_sort(), dns_journal_begin_transaction(),
* dns_journal_writediff(), and dns_journal_commit().
*
* Requires:
*\li 'j' is open for writing.
*
* \li 'diff' contains exactly one SOA deletion, one SOA addition
* with a greater serial number, and possibly other changes,
* in arbitrary order.
*/
/**************************************************************************/
/*
* Reading transactions from journals.
*/
bool
dns_journal_empty(dns_journal_t *j);
/*<
* Find out if a journal is empty.
*/
bool
dns_journal_recovered(dns_journal_t *j);
/*<
* Find out if the journal could be opened using old journal format
*/
uint32_t
dns_journal_first_serial(dns_journal_t *j);
uint32_t
dns_journal_last_serial(dns_journal_t *j);
/*%<
* Get the first and last addressable serial number in the journal.
*/
isc_result_t
dns_journal_iter_init(dns_journal_t *j, uint32_t begin_serial,
uint32_t end_serial, size_t *xfrsizep);
/*%<
* Prepare to iterate over the transactions that will bring the database
* from SOA serial number 'begin_serial' to 'end_serial'.
*
* If 'xfrsizep' is not NULL, then on success it will be set to the
* total size of all records in the iteration (excluding headers). This
* is meant to be a rough approximation of the size of an incremental
* zone transfer, though it does not account for DNS message overhead
* or name compression.)
*
* Returns:
*\li ISC_R_SUCCESS
*\li ISC_R_RANGE begin_serial is outside the addressable range.
*\li ISC_R_NOTFOUND begin_serial is within the range of addressable
* serial numbers covered by the journal, but
* this particular serial number does not exist.
*/
/*@{*/
isc_result_t
dns_journal_first_rr(dns_journal_t *j);
isc_result_t
dns_journal_next_rr(dns_journal_t *j);
/*%<
* Position the iterator at the first/next RR in a journal
* transaction sequence established using dns_journal_iter_init().
*
* Requires:
* \li dns_journal_iter_init() has been called.
*
*/
/*@}*/
void
dns_journal_current_rr(dns_journal_t *j, dns_name_t **name, uint32_t *ttl,
dns_rdata_t **rdata);
/*%<
* Get the name, ttl, and rdata of the current journal RR.
*
* Requires:
* \li The last call to dns_journal_first_rr() or dns_journal_next_rr()
* returned ISC_R_SUCCESS.
*/
/**************************************************************************/
/*
* Database roll-forward.
*/
isc_result_t
dns_journal_rollforward(dns_journal_t *j, dns_db_t *db, unsigned int options);
/*%<
* Roll forward (play back) the journal file "filename" into the
* database "db". This should be called when the server starts
* after a shutdown or crash.
*
* Requires:
*\li 'journal' is a valid journal
*\li 'db' is a valid database which does not have a version
* open for writing.
*
* Returns:
*\li ISC_R_NOTFOUND when current serial in not in journal.
*\li ISC_R_RANGE when current serial in not in journals range.
*\li DNS_R_UPTODATE when the database was already up to date.
*\li ISC_R_SUCCESS journal has been applied successfully to the
* database without any issues.
*
* others
*/
isc_result_t
dns_journal_print(isc_mem_t *mctx, uint32_t flags, const char *filename,
FILE *file);
/* For debugging not general use */
isc_result_t
dns_db_diff(isc_mem_t *mctx, dns_db_t *dba, dns_dbversion_t *dbvera,
dns_db_t *dbb, dns_dbversion_t *dbverb,
const char *journal_filename);
isc_result_t
dns_db_diffx(dns_diff_t *diff, dns_db_t *dba, dns_dbversion_t *dbvera,
dns_db_t *dbb, dns_dbversion_t *dbverb,
const char *journal_filename);
/*%<
* Compare the databases 'dba' and 'dbb' and generate a diff/journal
* entry containing the changes to make 'dba' from 'dbb' (note
* the order). This journal entry will consist of a single,
* possibly very large transaction. Append the journal
* entry to the journal file specified by 'journal_filename' if
* non-NULL.
*/
isc_result_t
dns_journal_compact(isc_mem_t *mctx, char *filename, uint32_t serial,
uint32_t flags, uint32_t target_size);
/*%<
* Attempt to compact the journal if it is greater that 'target_size'.
* Changes from 'serial' onwards will be preserved. Changes prior than
* that may be dropped in order to get the journal below `target_size`.
*
* If 'flags' includes DNS_JOURNAL_COMPACTALL, the entire journal is copied.
* In this case, `serial` is ignored. This flag is used when upgrading or
* downgrading the format version of the journal. If 'flags' also includes
* DNS_JOURNAL_VERSION1, then the journal is copied out in the original
* format used prior to BIND 9.16.12; otherwise it is copied in the
* current format.
*
* If _COMPACTALL is not in use, and the journal file exists and is
* non-empty, then 'serial' must exist in the journal.
*
* Returns:
*\li ISC_R_SUCCESS
*\li ISC_R_RANGE serial is outside the range existing in the journal
*
* Other errors may be returned from file operations.
*/
bool
dns_journal_get_sourceserial(dns_journal_t *j, uint32_t *sourceserial);
void
dns_journal_set_sourceserial(dns_journal_t *j, uint32_t sourceserial);
/*%<
* Get and set source serial.
*
* Returns:
* true if sourceserial has previously been set.
*/
ISC_LANG_ENDDECLS
#endif /* DNS_JOURNAL_H */
