/*
* 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_DIFF_H
#define DNS_DIFF_H 1
/*****
***** Module Info
*****/
/*! \file dns/diff.h
* \brief
* A diff is a convenience type representing a list of changes to be
* made to a database.
*/
/***
*** Imports
***/
#include <isc/lang.h>
#include <isc/magic.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/types.h>
/***
*** Types
***/
/*%
* A dns_difftuple_t represents a single RR being added or deleted.
* The RR type and class are in the 'rdata' member; the class is always
* the real one, not a DynDNS meta-class, so that the rdatas can be
* compared using dns_rdata_compare(). The TTL is significant
* even for deletions, because a deletion/addition pair cannot
* be canceled out if the TTL differs (it might be an explicit
* TTL update).
*
* Tuples are also used to represent complete RRs with owner
* names for a couple of other purposes, such as the
* individual RRs of a "RRset exists (value dependent)"
* prerequisite set. In this case, op==DNS_DIFFOP_EXISTS,
* and the TTL is ignored.
*
* DNS_DIFFOP_*RESIGN will cause the 'resign' attribute of the resulting
* RRset to be recomputed to be 'resign' seconds before the earliest RRSIG
* timeexpire.
*/
typedef enum {
DNS_DIFFOP_ADD = 0, /*%< Add an RR. */
DNS_DIFFOP_DEL = 1, /*%< Delete an RR. */
DNS_DIFFOP_EXISTS = 2, /*%< Assert RR existence. */
DNS_DIFFOP_ADDRESIGN = 4, /*%< ADD + RESIGN. */
DNS_DIFFOP_DELRESIGN = 5 /*%< DEL + RESIGN. */
} dns_diffop_t;
typedef struct dns_difftuple dns_difftuple_t;
typedef ISC_LIST(dns_difftuple_t) dns_difftuplelist_t;
#define DNS_DIFFTUPLE_MAGIC ISC_MAGIC('D', 'I', 'F', 'T')
#define DNS_DIFFTUPLE_VALID(t) ISC_MAGIC_VALID(t, DNS_DIFFTUPLE_MAGIC)
struct dns_difftuple {
unsigned int magic;
isc_mem_t *mctx;
dns_diffop_t op;
dns_name_t name;
dns_ttl_t ttl;
dns_rdata_t rdata;
ISC_LINK(dns_difftuple_t) link;
/* Variable-size name data and rdata follows. */
};
/*%
* A dns_diff_t represents a set of changes being applied to
* a zone. Diffs are also used to represent "RRset exists
* (value dependent)" prerequisites.
*/
typedef struct dns_diff dns_diff_t;
#define DNS_DIFF_MAGIC ISC_MAGIC('D', 'I', 'F', 'F')
#define DNS_DIFF_VALID(t) ISC_MAGIC_VALID(t, DNS_DIFF_MAGIC)
struct dns_diff {
unsigned int magic;
isc_mem_t *mctx;
dns_difftuplelist_t tuples;
};
/* Type of comparison function for sorting diffs. */
typedef int
dns_diff_compare_func(const void *, const void *);
/***
*** Functions
***/
ISC_LANG_BEGINDECLS
/**************************************************************************/
/*
* Manipulation of diffs and tuples.
*/
isc_result_t
dns_difftuple_create(isc_mem_t *mctx, dns_diffop_t op, const dns_name_t *name,
dns_ttl_t ttl, dns_rdata_t *rdata, dns_difftuple_t **tp);
/*%<
* Create a tuple. Deep copies are made of the name and rdata, so
* they need not remain valid after the call.
*
* Requires:
*\li *tp != NULL && *tp == NULL.
*
* Returns:
*\li ISC_R_SUCCESS
* \li ISC_R_NOMEMORY
*/
void
dns_difftuple_free(dns_difftuple_t **tp);
/*%<
* Free a tuple.
*
* Requires:
* \li **tp is a valid tuple.
*
* Ensures:
* \li *tp == NULL
* \li All memory used by the tuple is freed.
*/
isc_result_t
dns_difftuple_copy(dns_difftuple_t *orig, dns_difftuple_t **copyp);
/*%<
* Copy a tuple.
*
* Requires:
* \li 'orig' points to a valid tuple
*\li copyp != NULL && *copyp == NULL
*/
void
dns_diff_init(isc_mem_t *mctx, dns_diff_t *diff);
/*%<
* Initialize a diff.
*
* Requires:
* \li 'diff' points to an uninitialized dns_diff_t
* \li allocated by the caller.
*
* Ensures:
* \li '*diff' is a valid, empty diff.
*/
void
dns_diff_clear(dns_diff_t *diff);
/*%<
* Clear a diff, destroying all its tuples.
*
* Requires:
* \li 'diff' points to a valid dns_diff_t.
*
* Ensures:
* \li Any tuples in the diff are destroyed.
* The diff now empty, but it is still valid
* and may be reused without calling dns_diff_init
* again. The only memory used is that of the
* dns_diff_t structure itself.
*
* Notes:
* \li Managing the memory of the dns_diff_t structure itself
* is the caller's responsibility.
*/
void
dns_diff_append(dns_diff_t *diff, dns_difftuple_t **tuple);
/*%<
* Append a single tuple to a diff.
*
*\li 'diff' is a valid diff.
* \li '*tuple' is a valid tuple.
*
* Ensures:
*\li *tuple is NULL.
*\li The tuple has been freed, or will be freed when the diff is cleared.
*/
void
dns_diff_appendminimal(dns_diff_t *diff, dns_difftuple_t **tuple);
/*%<
* Append 'tuple' to 'diff', removing any duplicate
* or conflicting updates as needed to create a minimal diff.
*
* Requires:
*\li 'diff' is a minimal diff.
*
* Ensures:
*\li 'diff' is still a minimal diff.
* \li *tuple is NULL.
* \li The tuple has been freed, or will be freed when the diff is
* cleared.
*
*/
isc_result_t
dns_diff_sort(dns_diff_t *diff, dns_diff_compare_func *compare);
/*%<
* Sort 'diff' in-place according to the comparison function 'compare'.
*/
isc_result_t
dns_diff_apply(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver);
isc_result_t
dns_diff_applysilently(dns_diff_t *diff, dns_db_t *db, dns_dbversion_t *ver);
/*%<
* Apply 'diff' to the database 'db'.
*
* dns_diff_apply() logs warnings about updates with no effect or
* with inconsistent TTLs; dns_diff_applysilently() does not.
*
* For efficiency, the diff should be sorted by owner name.
* If it is not sorted, operation will still be correct,
* but less efficient.
*
* Requires:
*\li *diff is a valid diff (possibly empty), containing
* tuples of type #DNS_DIFFOP_ADD and/or
* For #DNS_DIFFOP_DEL tuples, the TTL is ignored.
*
*/
isc_result_t
dns_diff_load(dns_diff_t *diff, dns_addrdatasetfunc_t addfunc,
void *add_private);
/*%<
* Like dns_diff_apply, but for use when loading a new database
* instead of modifying an existing one. This bypasses the
* database transaction mechanisms.
*
* Requires:
*\li 'addfunc' is a valid dns_addradatasetfunc_t obtained from
* dns_db_beginload()
*
*\li 'add_private' points to a corresponding dns_dbload_t *
* (XXX why is it a void pointer, then?)
*/
isc_result_t
dns_diff_print(dns_diff_t *diff, FILE *file);
/*%<
* Print the differences to 'file' or if 'file' is NULL via the
* logging system.
*
* Require:
*\li 'diff' to be valid.
*\li 'file' to refer to a open file or NULL.
*
* Returns:
*\li #ISC_R_SUCCESS
*\li #ISC_R_NOMEMORY
*\li #ISC_R_UNEXPECTED
*\li any error from dns_rdataset_totext()
*/
ISC_LANG_ENDDECLS
#endif /* DNS_DIFF_H */
