rdataslab.h

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/*
 * Copyright (C) 2004-2008  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: rdataslab.h,v 1.33 2008/04/01 23:47:10 tbox Exp $ */

#ifndef DNS_RDATASLAB_H
#define DNS_RDATASLAB_H 1

/*! \file dns/rdataslab.h
 * \brief
 * Implements storage of rdatasets into slabs of memory.
 *
 * MP:
 *\li   Clients of this module must impose any required synchronization.
 *
 * Reliability:
 *\li   This module deals with low-level byte streams.  Errors in any of
 *      the functions are likely to crash the server or corrupt memory.
 *
 *\li   If the caller passes invalid memory references, these functions are
 *      likely to crash the server or corrupt memory.
 *
 * Resources:
 *\li   None.
 *
 * Security:
 *\li   None.
 *
 * Standards:
 *\li   None.
 */

/***
 *** Imports
 ***/

#include <isc/lang.h>

#include <dns/types.h>

ISC_LANG_BEGINDECLS

#define DNS_RDATASLAB_FORCE 0x1
#define DNS_RDATASLAB_EXACT 0x2

#define DNS_RDATASLAB_OFFLINE 0x01      /* RRSIG is for offline DNSKEY */
#define DNS_RDATASLAB_WARNMASK 0x0E     /*%< RRSIG(DNSKEY) expired
                                         * warnings number mask. */
#define DNS_RDATASLAB_WARNSHIFT 1       /*%< How many bits to shift to find
                                         * remaining expired warning number. */


/***
 *** Functions
 ***/

isc_result_t
dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx,
                           isc_region_t *region, unsigned int reservelen);
/*%<
 * Slabify a rdataset.  The slab area will be allocated and returned
 * in 'region'.
 *
 * Requires:
 *\li   'rdataset' is valid.
 *
 * Ensures:
 *\li   'region' will have base pointing to the start of allocated memory,
 *      with the slabified region beginning at region->base + reservelen.
 *      region->length contains the total length allocated.
 *
 * Returns:
 *\li   ISC_R_SUCCESS           - successful completion
 *\li   ISC_R_NOMEMORY          - no memory.
 *\li   XXX others
 */

void
dns_rdataslab_tordataset(unsigned char *slab, unsigned int reservelen,
                         dns_rdataclass_t rdclass, dns_rdatatype_t rdtype,
                         dns_rdatatype_t covers, dns_ttl_t ttl,
                         dns_rdataset_t *rdataset);
/*%<
 * Construct an rdataset from a slab.
 *
 * Requires:
 *\li   'slab' points to a slab.
 *\li   'rdataset' is disassociated.
 *
 * Ensures:
 *\li   'rdataset' is associated and points to a valid rdataest.
 */
unsigned int
dns_rdataslab_size(unsigned char *slab, unsigned int reservelen);
/*%<
 * Return the total size of an rdataslab.
 *
 * Requires:
 *\li   'slab' points to a slab.
 *
 * Returns:
 *\li   The number of bytes in the slab, including the reservelen.
 */

isc_result_t
dns_rdataslab_merge(unsigned char *oslab, unsigned char *nslab,
                    unsigned int reservelen, isc_mem_t *mctx,
                    dns_rdataclass_t rdclass, dns_rdatatype_t type,
                    unsigned int flags, unsigned char **tslabp);
/*%<
 * Merge 'oslab' and 'nslab'.
 */

isc_result_t
dns_rdataslab_subtract(unsigned char *mslab, unsigned char *sslab,
                       unsigned int reservelen, isc_mem_t *mctx,
                       dns_rdataclass_t rdclass, dns_rdatatype_t type,
                       unsigned int flags, unsigned char **tslabp);
/*%<
 * Subtract 'sslab' from 'mslab'.  If 'exact' is true then all elements
 * of 'sslab' must exist in 'mslab'.
 *
 * XXX
 * valid flags are DNS_RDATASLAB_EXACT
 */

isc_boolean_t
dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2,
                    unsigned int reservelen);
/*%<
 * Compare two rdataslabs for equality.  This does _not_ do a full
 * DNSSEC comparison.
 *
 * Requires:
 *\li   'slab1' and 'slab2' point to slabs.
 *
 * Returns:
 *\li   ISC_TRUE if the slabs are equal, ISC_FALSE otherwise.
 */
isc_boolean_t
dns_rdataslab_equalx(unsigned char *slab1, unsigned char *slab2,
                     unsigned int reservelen, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type);
/*%<
 * Compare two rdataslabs for DNSSEC equality.
 *
 * Requires:
 *\li   'slab1' and 'slab2' point to slabs.
 *
 * Returns:
 *\li   ISC_TRUE if the slabs are equal, #ISC_FALSE otherwise.
 */

ISC_LANG_ENDDECLS

#endif /* DNS_RDATASLAB_H */

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