Add BIND 9.2.4rc7.

[dragonfly.git] / contrib / bind-9.2.4rc7 / lib / dns / include / dns / rdataset.h

/*
 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1999-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and 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: rdataset.h,v 1.41.2.6 2004/03/09 06:11:20 marka Exp $ */

#ifndef DNS_RDATASET_H
#define DNS_RDATASET_H 1

/*****
 ***** Module Info
 *****/

/*
 * DNS Rdataset
 *
 * A DNS rdataset is a handle that can be associated with a collection of
 * rdata all having a common owner name, class, and type.
 *
 * The dns_rdataset_t type is like a "virtual class".  To actually use
 * rdatasets, an implementation of the method suite (e.g. "slabbed rdata") is
 * required.
 *
 * XXX <more> XXX
 *
 * MP:
 *      Clients of this module must impose any required synchronization.
 *
 * Reliability:
 *      No anticipated impact.
 *
 * Resources:
 *      <TBS>
 *
 * Security:
 *      No anticipated impact.
 *
 * Standards:
 *      None.
 */

#include <isc/lang.h>
#include <isc/magic.h>

#include <dns/types.h>

ISC_LANG_BEGINDECLS

typedef struct dns_rdatasetmethods {
        void                    (*disassociate)(dns_rdataset_t *rdataset);
        isc_result_t            (*first)(dns_rdataset_t *rdataset);
        isc_result_t            (*next)(dns_rdataset_t *rdataset);
        void                    (*current)(dns_rdataset_t *rdataset,
                                           dns_rdata_t *rdata);
        void                    (*clone)(dns_rdataset_t *source,
                                         dns_rdataset_t *target);
        unsigned int            (*count)(dns_rdataset_t *rdataset);
} dns_rdatasetmethods_t;

#define DNS_RDATASET_MAGIC             ISC_MAGIC('D','N','S','R')
#define DNS_RDATASET_VALID(set)        ISC_MAGIC_VALID(set, DNS_RDATASET_MAGIC)

/*
 * Direct use of this structure by clients is strongly discouraged, except
 * for the 'link' field which may be used however the client wishes.  The
 * 'private', 'current', and 'index' fields MUST NOT be changed by clients.
 * rdataset implementations may change any of the fields.
 */
struct dns_rdataset {
        unsigned int                    magic;          /* XXX ? */
        dns_rdatasetmethods_t *         methods;
        ISC_LINK(dns_rdataset_t)        link;
        /*
         * XXX do we need these, or should they be retrieved by methods?
         * Leaning towards the latter, since they are not frequently required
         * once you have the rdataset.
         */
        dns_rdataclass_t                rdclass;
        dns_rdatatype_t                 type;
        dns_ttl_t                       ttl;
        dns_trust_t                     trust;
        dns_rdatatype_t                 covers;
        /*
         * attributes
         */
        unsigned int                    attributes;
        /*
         * These are for use by the rdataset implementation, and MUST NOT
         * be changed by clients.
         */
        void *                          private1;
        void *                          private2;
        void *                          private3;
        unsigned int                    privateuint4;
        void *                          private5;
};

/*
 * _RENDERED:
 *      Used by message.c to indicate that the rdataset was rendered.
 *
 * _TTLADJUSTED:
 *      Used by message.c to indicate that the rdataset's rdata had differing
 *      TTL values, and the rdataset->ttl holds the smallest.
 */
#define DNS_RDATASETATTR_QUESTION       0x0001
#define DNS_RDATASETATTR_RENDERED       0x0002          /* Used by message.c */
#define DNS_RDATASETATTR_ANSWERED       0x0004          /* Used by server. */
#define DNS_RDATASETATTR_CACHE          0x0008          /* Used by resolver. */
#define DNS_RDATASETATTR_ANSWER         0x0010          /* Used by resolver. */
#define DNS_RDATASETATTR_ANSWERSIG      0x0020          /* Used by resolver. */
#define DNS_RDATASETATTR_EXTERNAL       0x0040          /* Used by resolver. */
#define DNS_RDATASETATTR_NCACHE         0x0080          /* Used by resolver. */
#define DNS_RDATASETATTR_CHAINING       0x0100          /* Used by resolver. */
#define DNS_RDATASETATTR_TTLADJUSTED    0x0200          /* Used by message.c */
#define DNS_RDATASETATTR_FIXEDORDER     0x0400
#define DNS_RDATASETATTR_RANDOMIZE      0x0800
#define DNS_RDATASETATTR_CHASE          0x1000          /* Used by resolver. */
#define DNS_RDATASETATTR_NXDOMAIN       0x2000

void
dns_rdataset_init(dns_rdataset_t *rdataset);
/*
 * Make 'rdataset' a valid, disassociated rdataset.
 *
 * Requires:
 *      'rdataset' is not NULL.
 *
 * Ensures:
 *      'rdataset' is a valid, disassociated rdataset.
 */

void
dns_rdataset_invalidate(dns_rdataset_t *rdataset);
/*
 * Invalidate 'rdataset'.
 *
 * Requires:
 *      'rdataset' is a valid, disassociated rdataset.
 *
 * Ensures:
 *      If assertion checking is enabled, future attempts to use 'rdataset'
 *      without initializing it will cause an assertion failure.
 */

void
dns_rdataset_disassociate(dns_rdataset_t *rdataset);
/*
 * Disassociate 'rdataset' from its rdata, allowing it to be reused.
 *
 * Notes:
 *      The client must ensure it has no references to rdata in the rdataset
 *      before disassociating.
 *
 * Requires:
 *      'rdataset' is a valid, associated rdataset.
 *
 * Ensures:
 *      'rdataset' is a valid, disassociated rdataset.
 */

isc_boolean_t
dns_rdataset_isassociated(dns_rdataset_t *rdataset);
/*
 * Is 'rdataset' associated?
 *
 * Requires:
 *      'rdataset' is a valid rdataset.
 *
 * Returns:
 *      ISC_TRUE                        'rdataset' is associated.
 *      ISC_FALSE                       'rdataset' is not associated.
 */

void
dns_rdataset_makequestion(dns_rdataset_t *rdataset, dns_rdataclass_t rdclass,
                          dns_rdatatype_t type);
/*
 * Make 'rdataset' a valid, associated, question rdataset, with a
 * question class of 'rdclass' and type 'type'.
 *
 * Notes:
 *      Question rdatasets have a class and type, but no rdata.
 *
 * Requires:
 *      'rdataset' is a valid, disassociated rdataset.
 *
 * Ensures:
 *      'rdataset' is a valid, associated, question rdataset.
 */

void
dns_rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target);
/*
 * Make 'target' refer to the same rdataset as 'source'.
 *
 * Requires:
 *      'source' is a valid, associated rdataset.
 *
 *      'target' is a valid, dissociated rdataset.
 *
 * Ensures:
 *      'target' references the same rdataset as 'source'.
 */

unsigned int
dns_rdataset_count(dns_rdataset_t *rdataset);
/*
 * Return the number of records in 'rdataset'.
 *
 * Requires:
 *      'rdataset' is a valid, associated rdataset.
 *
 * Returns:
 *      The number of records in 'rdataset'.
 */

isc_result_t
dns_rdataset_first(dns_rdataset_t *rdataset);
/*
 * Move the rdata cursor to the first rdata in the rdataset (if any).
 *
 * Requires:
 *      'rdataset' is a valid, associated rdataset.
 *
 * Returns:
 *      ISC_R_SUCCESS
 *      ISC_R_NOMORE                    There are no rdata in the set.
 */

isc_result_t
dns_rdataset_next(dns_rdataset_t *rdataset);
/*
 * Move the rdata cursor to the next rdata in the rdataset (if any).
 *
 * Requires:
 *      'rdataset' is a valid, associated rdataset.
 *
 * Returns:
 *      ISC_R_SUCCESS
 *      ISC_R_NOMORE                    There are no more rdata in the set.
 */

void
dns_rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata);
/*
 * Make 'rdata' refer to the current rdata.
 *
 * Notes:
 *
 *      The data returned in 'rdata' is valid for the life of the
 *      rdataset; in particular, subsequent changes in the cursor position
 *      do not invalidate 'rdata'.
 *
 * Requires:
 *      'rdataset' is a valid, associated rdataset.
 *
 *      The rdata cursor of 'rdataset' is at a valid location (i.e. the
 *      result of last call to a cursor movement command was ISC_R_SUCCESS).
 *
 * Ensures:
 *      'rdata' refers to the rdata at the rdata cursor location of
 *      'rdataset'.
 */

isc_result_t
dns_rdataset_totext(dns_rdataset_t *rdataset,
                    dns_name_t *owner_name,
                    isc_boolean_t omit_final_dot,
                    isc_boolean_t question,
                    isc_buffer_t *target);
/*
 * Convert 'rdataset' to text format, storing the result in 'target'.
 *
 * Notes:
 *      The rdata cursor position will be changed.
 *
 *      The 'question' flag should normally be ISC_FALSE.  If it is 
 *      ISC_TRUE, the TTL and rdata fields are not printed.  This is 
 *      for use when printing an rdata representing a question section.
 *
 *      This interface is deprecated; use dns_master_rdatasettottext()
 *      and/or dns_master_questiontotext() instead.
 *
 * Requires:
 *      'rdataset' is a valid rdataset.
 *
 *      'rdataset' is not empty.
 */

isc_result_t
dns_rdataset_towire(dns_rdataset_t *rdataset,
                    dns_name_t *owner_name,
                    dns_compress_t *cctx,
                    isc_buffer_t *target,
                    unsigned int *countp);
/*
 * Convert 'rdataset' to wire format, compressing names as specified
 * in 'cctx', and storing the result in 'target'.
 *
 * Notes:
 *      The rdata cursor position will be changed.
 *
 *      The number of RRs added to target will be added to *countp.
 *
 * Requires:
 *      'rdataset' is a valid rdataset.
 *
 *      'rdataset' is not empty.
 *
 *      'countp' is a valid pointer.
 *
 * Ensures:
 *      On a return of ISC_R_SUCCESS, 'target' contains a wire format
 *      for the data contained in 'rdataset'.  Any error return leaves
 *      the buffer unchanged.
 *
 *      *countp has been incremented by the number of RRs added to
 *      target.
 *
 * Returns:
 *      ISC_R_SUCCESS           - all ok
 *      ISC_R_NOSPACE           - 'target' doesn't have enough room
 *
 *      Any error returned by dns_rdata_towire(), dns_rdataset_next(),
 *      dns_name_towire().
 */

isc_result_t
dns_rdataset_towiresorted(dns_rdataset_t *rdataset,
                          dns_name_t *owner_name,
                          dns_compress_t *cctx,
                          isc_buffer_t *target,
                          dns_rdatasetorderfunc_t order,
                          void *order_arg,
                          unsigned int *countp);
/*
 * Like dns_rdataset_towire(), but sorting the rdatasets according to
 * the integer value returned by 'order' when called witih the rdataset
 * and 'order_arg' as arguments.
 *
 * Requires:
 *      All the requirements of dns_rdataset_towire(), and
 *      that order_arg is NULL if and only if order is NULL.
 */

isc_result_t
dns_rdataset_towirepartial(dns_rdataset_t *rdataset,
                           dns_name_t *owner_name,
                           dns_compress_t *cctx,
                           isc_buffer_t *target,
                           dns_rdatasetorderfunc_t order,
                           void *order_arg,
                           unsigned int *countp,
                           void **state);
/*
 * Like dns_rdataset_towiresorted() except that a partial rdataset
 * may be written.
 *
 * Requires:
 *      All the requirements of dns_rdataset_towiresorted().
 *      If 'state' is non NULL then the current position in the
 *      rdataset will be remembered if the rdataset in not
 *      completely written and should be passed on on subsequent
 *      calls (NOT CURRENTLY IMPLEMENTED).
 *
 * Returns:
 *      ISC_R_SUCCESS if all of the records were written.
 *      ISC_R_NOSPACE if unable to fit in all of the records. *countp
 *                    will be updated to reflect the number of records
 *                    written.
 */


isc_result_t
dns_rdataset_additionaldata(dns_rdataset_t *rdataset,
                            dns_additionaldatafunc_t add, void *arg);
/*
 * For each rdata in rdataset, call 'add' for each name and type in the
 * rdata which is subject to additional section processing.
 *
 * Requires:
 *
 *      'rdataset' is a valid, non-question rdataset.
 *
 *      'add' is a valid dns_additionaldatafunc_t
 *
 * Ensures:
 *
 *      If successful, dns_rdata_additionaldata() will have been called for
 *      each rdata in 'rdataset'.
 *
 *      If a call to dns_rdata_additionaldata() is not successful, the
 *      result returned will be the result of dns_rdataset_additionaldata().
 *
 * Returns:
 *
 *      ISC_R_SUCCESS
 *
 *      Any error that dns_rdata_additionaldata() can return.
 */

ISC_LANG_ENDDECLS

#endif /* DNS_RDATASET_H */