/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * 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: rdata.c,v 1.37 2024/12/09 12:24:01 florian Exp $ */

/*! \file */

#include <arpa/inet.h>

#include <stdlib.h>
#include <string.h>

#include <isc/base64.h>
#include <isc/hex.h>
#include <isc/util.h>
#include <isc/buffer.h>

#include <dns/cert.h>
#include <dns/compress.h>
#include <dns/keyvalues.h>
#include <dns/rcode.h>
#include <dns/rdata.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/time.h>
#include <dns/ttl.h>

#define RETERR(x) \
        do { \
                isc_result_t _r = (x); \
                if (_r != ISC_R_SUCCESS) \
                        return (_r); \
        } while (0)

#define ARGS_TOTEXT     dns_rdata_t *rdata, dns_rdata_textctx_t *tctx, \
                        isc_buffer_t *target

#define ARGS_FROMWIRE   int rdclass, dns_rdatatype_t type, \
                        isc_buffer_t *source, dns_decompress_t *dctx, \
                        unsigned int options, isc_buffer_t *target

#define ARGS_TOWIRE     dns_rdata_t *rdata, dns_compress_t *cctx, \
                        isc_buffer_t *target

#define ARGS_FROMSTRUCT int rdclass, dns_rdatatype_t type, \
                        void *source, isc_buffer_t *target

#define ARGS_TOSTRUCT   const dns_rdata_t *rdata, void *target

#define ARGS_FREESTRUCT void *source

#define ARGS_CHECKOWNER dns_name_t *name, dns_rdataclass_t rdclass, \
                        dns_rdatatype_t type, int wildcard

/*%
 * Context structure for the totext_ functions.
 * Contains formatting options for rdata-to-text
 * conversion.
 */
typedef struct dns_rdata_textctx {
        dns_name_t *origin;     /*%< Current origin, or NULL. */
        unsigned int flags;     /*%< DNS_STYLEFLAG_*  */
        unsigned int width;     /*%< Width of rdata column. */
        const char *linebreak;  /*%< Line break string. */
} dns_rdata_textctx_t;

typedef struct dns_rdata_type_lookup {
        const char      *type;
        int              val;
} dns_rdata_type_lookup_t;

static isc_result_t
txt_totext(isc_region_t *source, int quote, isc_buffer_t *target);

static isc_result_t
txt_fromwire(isc_buffer_t *source, isc_buffer_t *target);

static isc_result_t
multitxt_totext(isc_region_t *source, isc_buffer_t *target);

static int
name_prefix(dns_name_t *name, dns_name_t *origin, dns_name_t *target);

static unsigned int
name_length(dns_name_t *name);

static isc_result_t
inet_totext(int af, isc_region_t *src, isc_buffer_t *target);

static int
buffer_empty(isc_buffer_t *source);

static isc_result_t
uint32_tobuffer(uint32_t, isc_buffer_t *target);

static isc_result_t
uint16_tobuffer(uint32_t, isc_buffer_t *target);

static isc_result_t
name_tobuffer(dns_name_t *name, isc_buffer_t *target);

static uint32_t
uint32_fromregion(isc_region_t *region);

static uint16_t
uint16_fromregion(isc_region_t *region);

static uint8_t
uint8_fromregion(isc_region_t *region);

static uint8_t
uint8_consume_fromregion(isc_region_t *region);

static isc_result_t
btoa_totext(unsigned char *inbuf, int inbuflen, isc_buffer_t *target);

static isc_result_t
rdata_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
             isc_buffer_t *target);

static isc_result_t
unknown_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
               isc_buffer_t *target);

static inline isc_result_t
generic_totext_key(ARGS_TOTEXT);

static inline isc_result_t
generic_fromwire_key(ARGS_FROMWIRE);

static isc_result_t
generic_totext_txt(ARGS_TOTEXT);

static isc_result_t
generic_fromwire_txt(ARGS_FROMWIRE);

static isc_result_t
generic_totext_ds(ARGS_TOTEXT);

static isc_result_t
generic_fromwire_ds(ARGS_FROMWIRE);

static isc_result_t
generic_totext_tlsa(ARGS_TOTEXT);

static isc_result_t
generic_fromwire_tlsa(ARGS_FROMWIRE);

static inline isc_result_t
name_duporclone(dns_name_t *source, dns_name_t *target) {

        return (dns_name_dup(source, target));
}

static inline void *
mem_maybedup(void *source, size_t length) {
        void *copy;

        copy = malloc(length);
        if (copy != NULL)
                memmove(copy, source, length);

        return (copy);
}

static inline isc_result_t
typemap_totext(isc_region_t *sr, dns_rdata_textctx_t *tctx,
               isc_buffer_t *target)
{
        unsigned int i, j, k;
        unsigned int window, len;
        int first = 1;

        for (i = 0; i < sr->length; i += len) {
                if (tctx != NULL &&
                    (tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0) {
                        RETERR(isc_str_tobuffer(tctx->linebreak, target));
                        first = 1;
                }
                INSIST(i + 2 <= sr->length);
                window = sr->base[i];
                len = sr->base[i + 1];
                INSIST(len > 0 && len <= 32);
                i += 2;
                INSIST(i + len <= sr->length);
                for (j = 0; j < len; j++) {
                        dns_rdatatype_t t;
                        if (sr->base[i + j] == 0)
                                continue;
                        for (k = 0; k < 8; k++) {
                                if ((sr->base[i + j] & (0x80 >> k)) == 0)
                                        continue;
                                t = window * 256 + j * 8 + k;
                                if (!first)
                                        RETERR(isc_str_tobuffer(" ", target));
                                first = 0;
                                RETERR(dns_rdatatype_totext(t, target));
                        }
                }
        }
        return (ISC_R_SUCCESS);
}

static isc_result_t
typemap_test(isc_region_t *sr, int allow_empty) {
        unsigned int window, lastwindow = 0;
        unsigned int len;
        int first = 1;
        unsigned int i;

        for (i = 0; i < sr->length; i += len) {
                /*
                 * Check for overflow.
                 */
                if (i + 2 > sr->length)
                        return (DNS_R_FORMERR);
                window = sr->base[i];
                len = sr->base[i + 1];
                i += 2;
                /*
                 * Check that bitmap windows are in the correct order.
                 */
                if (!first && window <= lastwindow)
                        return (DNS_R_FORMERR);
                /*
                 * Check for legal lengths.
                 */
                if (len < 1 || len > 32)
                        return (DNS_R_FORMERR);
                /*
                 * Check for overflow.
                 */
                if (i + len > sr->length)
                        return (DNS_R_FORMERR);
                /*
                 * The last octet of the bitmap must be non zero.
                 */
                if (sr->base[i + len - 1] == 0)
                        return (DNS_R_FORMERR);
                lastwindow = window;
                first = 0;
        }
        if (i != sr->length)
                return (DNS_R_EXTRADATA);
        if (!allow_empty && first)
                return (DNS_R_FORMERR);
        return (ISC_R_SUCCESS);
}

static const char decdigits[] = "0123456789";

#include "code.h"

/***
 *** Initialization
 ***/

void
dns_rdata_init(dns_rdata_t *rdata) {

        REQUIRE(rdata != NULL);

        rdata->data = NULL;
        rdata->length = 0;
        rdata->rdclass = 0;
        rdata->type = 0;
        rdata->flags = 0;
        ISC_LINK_INIT(rdata, link);
        /* ISC_LIST_INIT(rdata->list); */
}

void
dns_rdata_reset(dns_rdata_t *rdata) {

        REQUIRE(rdata != NULL);

        REQUIRE(!ISC_LINK_LINKED(rdata, link));
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        rdata->data = NULL;
        rdata->length = 0;
        rdata->rdclass = 0;
        rdata->type = 0;
        rdata->flags = 0;
}

/***
 ***
 ***/

void
dns_rdata_clone(const dns_rdata_t *src, dns_rdata_t *target) {

        REQUIRE(src != NULL);
        REQUIRE(target != NULL);

        REQUIRE(DNS_RDATA_INITIALIZED(target));

        REQUIRE(DNS_RDATA_VALIDFLAGS(src));
        REQUIRE(DNS_RDATA_VALIDFLAGS(target));

        target->data = src->data;
        target->length = src->length;
        target->rdclass = src->rdclass;
        target->type = src->type;
        target->flags = src->flags;
}

/***
 *** Conversions
 ***/

void
dns_rdata_fromregion(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type, isc_region_t *r)
{

        REQUIRE(rdata != NULL);
        REQUIRE(DNS_RDATA_INITIALIZED(rdata));
        REQUIRE(r != NULL);

        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        rdata->data = r->base;
        rdata->length = r->length;
        rdata->rdclass = rdclass;
        rdata->type = type;
        rdata->flags = 0;
}

void
dns_rdata_toregion(const dns_rdata_t *rdata, isc_region_t *r) {

        REQUIRE(rdata != NULL);
        REQUIRE(r != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        r->base = rdata->data;
        r->length = rdata->length;
}

isc_result_t
dns_rdata_fromwire(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
                   dns_rdatatype_t type, isc_buffer_t *source,
                   dns_decompress_t *dctx, unsigned int options,
                   isc_buffer_t *target)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_region_t region;
        isc_buffer_t ss;
        isc_buffer_t st;
        int use_default = 0;
        uint32_t activelength;
        unsigned int length;

        REQUIRE(dctx != NULL);
        if (rdata != NULL) {
                REQUIRE(DNS_RDATA_INITIALIZED(rdata));
                REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
        }
        REQUIRE(source != NULL);
        REQUIRE(target != NULL);

        if (type == 0)
                return (DNS_R_FORMERR);

        ss = *source;
        st = *target;

        activelength = isc_buffer_activelength(source);
        INSIST(activelength < 65536);

        FROMWIRESWITCH

        if (use_default) {
                if (activelength > isc_buffer_availablelength(target))
                        result = ISC_R_NOSPACE;
                else {
                        isc_buffer_putmem(target, isc_buffer_current(source),
                                          activelength);
                        isc_buffer_forward(source, activelength);
                        result = ISC_R_SUCCESS;
                }
        }

        /*
         * Reject any rdata that expands out to more than DNS_RDATA_MAXLENGTH
         * as we cannot transmit it.
         */
        length = isc_buffer_usedlength(target) - isc_buffer_usedlength(&st);
        if (result == ISC_R_SUCCESS && length > DNS_RDATA_MAXLENGTH)
                result = DNS_R_FORMERR;

        /*
         * We should have consumed all of our buffer.
         */
        if (result == ISC_R_SUCCESS && !buffer_empty(source))
                result = DNS_R_EXTRADATA;

        if (rdata != NULL && result == ISC_R_SUCCESS) {
                region.base = isc_buffer_used(&st);
                region.length = length;
                dns_rdata_fromregion(rdata, rdclass, type, &region);
        }

        if (result != ISC_R_SUCCESS) {
                *source = ss;
                *target = st;
        }
        return (result);
}

isc_result_t
dns_rdata_towire(dns_rdata_t *rdata, dns_compress_t *cctx,
                 isc_buffer_t *target)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        int use_default = 0;
        isc_region_t tr;
        isc_buffer_t st;

        REQUIRE(rdata != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        /*
         * Some DynDNS meta-RRs have empty rdata.
         */
        if ((rdata->flags & DNS_RDATA_UPDATE) != 0) {
                INSIST(rdata->length == 0);
                return (ISC_R_SUCCESS);
        }

        st = *target;

        TOWIRESWITCH

        if (use_default) {
                isc_buffer_availableregion(target, &tr);
                if (tr.length < rdata->length)
                        return (ISC_R_NOSPACE);
                memmove(tr.base, rdata->data, rdata->length);
                isc_buffer_add(target, rdata->length);
                return (ISC_R_SUCCESS);
        }
        if (result != ISC_R_SUCCESS) {
                *target = st;
                INSIST(target->used < 65536);
                dns_compress_rollback(cctx, (uint16_t)target->used);
        }
        return (result);
}

static isc_result_t
unknown_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
               isc_buffer_t *target)
{
        isc_result_t result;
        char buf[sizeof("65535")];
        isc_region_t sr;

        strlcpy(buf, "\\# ", sizeof(buf));
        result = isc_str_tobuffer(buf, target);
        if (result != ISC_R_SUCCESS)
                return (result);

        dns_rdata_toregion(rdata, &sr);
        INSIST(sr.length < 65536);
        snprintf(buf, sizeof(buf), "%u", sr.length);
        result = isc_str_tobuffer(buf, target);
        if (result != ISC_R_SUCCESS)
                return (result);

        if (sr.length != 0U) {
                if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
                        result = isc_str_tobuffer(" ( ", target);
                else
                        result = isc_str_tobuffer(" ", target);

                if (result != ISC_R_SUCCESS)
                        return (result);

                if (tctx->width == 0) /* No splitting */
                        result = isc_hex_totext(&sr, 0, "", target);
                else
                        result = isc_hex_totext(&sr, tctx->width - 2,
                                                tctx->linebreak,
                                                target);
                if (result == ISC_R_SUCCESS &&
                    (tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
                        result = isc_str_tobuffer(" )", target);
        }
        return (result);
}

static isc_result_t
rdata_totext(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
             isc_buffer_t *target)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        int use_default = 0;
        unsigned int cur;

        REQUIRE(rdata != NULL);
        REQUIRE(tctx->origin == NULL || dns_name_isabsolute(tctx->origin));

        /*
         * Some DynDNS meta-RRs have empty rdata.
         */
        if ((rdata->flags & DNS_RDATA_UPDATE) != 0) {
                INSIST(rdata->length == 0);
                return (ISC_R_SUCCESS);
        }

        cur = isc_buffer_usedlength(target);

        TOTEXTSWITCH

        if (use_default || (result == ISC_R_NOTIMPLEMENTED)) {
                unsigned int u = isc_buffer_usedlength(target);

                INSIST(u >= cur);
                isc_buffer_subtract(target, u - cur);
                result = unknown_totext(rdata, tctx, target);
        }

        return (result);
}

isc_result_t
dns_rdata_totext(dns_rdata_t *rdata, dns_name_t *origin, isc_buffer_t *target)
{
        dns_rdata_textctx_t tctx;

        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        /*
         * Set up formatting options for single-line output.
         */
        tctx.origin = origin;
        tctx.flags = 0;
        tctx.width = 60;
        tctx.linebreak = " ";
        return (rdata_totext(rdata, &tctx, target));
}

isc_result_t
dns_rdata_tofmttext(dns_rdata_t *rdata, dns_name_t *origin,
                    unsigned int flags, unsigned int width,
                    unsigned int split_width, const char *linebreak,
                    isc_buffer_t *target)
{
        dns_rdata_textctx_t tctx;

        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        /*
         * Set up formatting options for formatted output.
         */
        tctx.origin = origin;
        tctx.flags = flags;
        if (split_width == 0xffffffff)
                tctx.width = width;
        else
                tctx.width = split_width;

        if ((flags & DNS_STYLEFLAG_MULTILINE) != 0)
                tctx.linebreak = linebreak;
        else {
                if (split_width == 0xffffffff)
                        tctx.width = 60; /* Used for hex word length only. */
                tctx.linebreak = " ";
        }
        return (rdata_totext(rdata, &tctx, target));
}

isc_result_t
dns_rdata_fromstruct_soa(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type, dns_rdata_soa_t *soa,
                     isc_buffer_t *target)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_buffer_t st;
        isc_region_t region;
        unsigned int length;

        REQUIRE(soa != NULL);
        if (rdata != NULL) {
                REQUIRE(DNS_RDATA_INITIALIZED(rdata));
                REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
        }

        st = *target;
        result = fromstruct_soa(rdclass, type, soa, target);

        length = isc_buffer_usedlength(target) - isc_buffer_usedlength(&st);
        if (result == ISC_R_SUCCESS && length > DNS_RDATA_MAXLENGTH)
                result = ISC_R_NOSPACE;

        if (rdata != NULL && result == ISC_R_SUCCESS) {
                region.base = isc_buffer_used(&st);
                region.length = length;
                dns_rdata_fromregion(rdata, rdclass, type, &region);
        }
        if (result != ISC_R_SUCCESS)
                *target = st;
        return (result);
}

isc_result_t
dns_rdata_fromstruct_tsig(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type, dns_rdata_any_tsig_t *tsig,
                     isc_buffer_t *target)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_buffer_t st;
        isc_region_t region;
        unsigned int length;

        REQUIRE(tsig != NULL);
        if (rdata != NULL) {
                REQUIRE(DNS_RDATA_INITIALIZED(rdata));
                REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
        }

        st = *target;
        result = fromstruct_any_tsig(rdclass, type, tsig, target);

        length = isc_buffer_usedlength(target) - isc_buffer_usedlength(&st);
        if (result == ISC_R_SUCCESS && length > DNS_RDATA_MAXLENGTH)
                result = ISC_R_NOSPACE;

        if (rdata != NULL && result == ISC_R_SUCCESS) {
                region.base = isc_buffer_used(&st);
                region.length = length;
                dns_rdata_fromregion(rdata, rdclass, type, &region);
        }
        if (result != ISC_R_SUCCESS)
                *target = st;
        return (result);
}

isc_result_t
dns_rdata_tostruct_cname(const dns_rdata_t *rdata, dns_rdata_cname_t *cname) {
        REQUIRE(rdata != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        return (tostruct_cname(rdata, cname));
}

isc_result_t
dns_rdata_tostruct_ns(const dns_rdata_t *rdata, dns_rdata_ns_t *ns) {
        REQUIRE(rdata != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        return (tostruct_ns(rdata, ns));
}

isc_result_t
dns_rdata_tostruct_soa(const dns_rdata_t *rdata, dns_rdata_soa_t *soa) {
        REQUIRE(rdata != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        return (tostruct_soa(rdata, soa));
}

isc_result_t
dns_rdata_tostruct_tsig(const dns_rdata_t *rdata, dns_rdata_any_tsig_t *tsig) {
        REQUIRE(rdata != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));

        return (tostruct_any_tsig(rdata, tsig));
}

void
dns_rdata_freestruct_cname(dns_rdata_cname_t *cname) {
        REQUIRE(cname != NULL);

        freestruct_cname(cname);
}

void
dns_rdata_freestruct_ns(dns_rdata_ns_t *ns) {
        REQUIRE(ns != NULL);

        freestruct_ns(ns);
}

void
dns_rdata_freestruct_soa(dns_rdata_soa_t *soa) {
        REQUIRE(soa != NULL);

        freestruct_soa(soa);
}

void
dns_rdata_freestruct_tsig(dns_rdata_any_tsig_t *tsig) {
        REQUIRE(tsig != NULL);

        freestruct_any_tsig(tsig);
}

int
dns_rdata_checkowner_nsec3(dns_name_t *name, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type, int wildcard)
{
        return checkowner_nsec3(name, rdclass, type, wildcard);
}

unsigned int
dns_rdatatype_attributes(dns_rdatatype_t type)
{
        switch (type) {
        case 0:
        case 31:
        case 32:
        case 34:
        case 100:
        case 101:
        case 102:
                return (DNS_RDATATYPEATTR_RESERVED);
        default:
                return (0);
        }
}

static int
type_cmp(const void *k, const void *e)
{
        return (strcasecmp(k, ((const dns_rdata_type_lookup_t *)e)->type));
}

isc_result_t
dns_rdatatype_fromtext(dns_rdatatype_t *typep, isc_textregion_t *source) {
        /* This has to be sorted always. */
        static const dns_rdata_type_lookup_t type_lookup[] = {
                {"a",           1},
                {"a6",          38},
                {"aaaa",        28},
                {"afsdb",       18},
                {"any",         255},
                {"apl",         42},
                {"atma",        34},
                {"avc",         258},
                {"axfr",        252},
                {"caa",         257},
                {"cdnskey",     60},
                {"cds",         59},
                {"cert",        37},
                {"cname",       5},
                {"csync",       62},
                {"dhcid",       49},
                {"dlv",         32769},
                {"dname",       39},
                {"dnskey",      48},
                {"doa",         259},
                {"ds",          43},
                {"eid",         31},
                {"eui48",       108},
                {"eui64",       109},
                {"gid",         102},
                {"gpos",        27},
                {"hinfo",       13},
                {"hip",         55},
                {"https",       65},
                {"ipseckey",    45},
                {"isdn",        20},
                {"ixfr",        251},
                {"key",         25},
                {"keydata",     65533},
                {"kx",          36},
                {"l32",         105},
                {"l64",         106},
                {"loc",         29},
                {"lp",          107},
                {"maila",       254},
                {"mailb",       253},
                {"mb",          7},
                {"md",          3},
                {"mf",          4},
                {"mg",          8},
                {"minfo",       14},
                {"mr",          9},
                {"mx",          15},
                {"naptr",       35},
                {"nid",         104},
                {"nimloc",      32},
                {"ninfo",       56},
                {"ns",          2},
                {"nsap",        22},
                {"nsap-ptr",    23},
                {"nsec",        47},
                {"nsec3",       50},
                {"nsec3param",  51},
                {"null",        10},
                {"nxt",         30},
                {"openpgpkey",  61},
                {"opt",         41},
                {"ptr",         12},
                {"px",          26},
                {"reserved0",   0},
                {"resinfo",     261},
                {"rkey",        57},
                {"rp",          17},
                {"rrsig",       46},
                {"rt",          21},
                {"sig",         24},
                {"sink",        40},
                {"smimea",      53},
                {"soa",         6},
                {"spf",         99},
                {"srv",         33},
                {"sshfp",       44},
                {"svcb",        64},
                {"ta",          32768},
                {"talink",      58},
                {"tkey",        249},
                {"tlsa",        52},
                {"tsig",        250},
                {"txt",         16},
                {"uid",         101},
                {"uinfo",       100},
                {"unspec",      103},
                {"uri",         256},
                {"wks",         11},
                {"x25",         19},
                {"zonemd",      63},
        };
        const dns_rdata_type_lookup_t *p;
        unsigned int n;
        char lookup[sizeof("nsec3param")];

        n = source->length;

        if (n == 0)
                return (DNS_R_UNKNOWN);

        /* source->base is not required to be NUL terminated. */
        if ((size_t)snprintf(lookup, sizeof(lookup), "%.*s", n, source->base)
            >= sizeof(lookup))
                return (DNS_R_UNKNOWN);

        p = bsearch(lookup, type_lookup,
            sizeof(type_lookup)/sizeof(type_lookup[0]), sizeof(type_lookup[0]),
            type_cmp);

        if (p) {
                if ((dns_rdatatype_attributes(p->val) &
                    DNS_RDATATYPEATTR_RESERVED) != 0)
                        return (ISC_R_NOTIMPLEMENTED);
                *typep = p->val;
                return (ISC_R_SUCCESS);
        }

        if (n > 4 && strncasecmp("type", lookup, 4) == 0) {
                int val;
                const char *errstr;
                val = strtonum(lookup + 4, 0, UINT16_MAX, &errstr);
                if (errstr == NULL) {
                        *typep = val;
                        return (ISC_R_SUCCESS);
                }
        }

        return (DNS_R_UNKNOWN);
}

isc_result_t
dns_rdatatype_totext(dns_rdatatype_t type, isc_buffer_t *target) {
        char buf[sizeof("TYPE65535")];

        switch (type) {
        case 0:
                return (isc_str_tobuffer("RESERVED0", target));
        case 1:
                return (isc_str_tobuffer("A", target));
        case 2:
                return (isc_str_tobuffer("NS", target));
        case 3:
                return (isc_str_tobuffer("MD", target));
        case 4:
                return (isc_str_tobuffer("MF", target));
        case 5:
                return (isc_str_tobuffer("CNAME", target));
        case 6:
                return (isc_str_tobuffer("SOA", target));
        case 7:
                return (isc_str_tobuffer("MB", target));
        case 8:
                return (isc_str_tobuffer("MG", target));
        case 9:
                return (isc_str_tobuffer("MR", target));
        case 10:
                return (isc_str_tobuffer("NULL", target));
        case 11:
                return (isc_str_tobuffer("WKS", target));
        case 12:
                return (isc_str_tobuffer("PTR", target));
        case 13:
                return (isc_str_tobuffer("HINFO", target));
        case 14:
                return (isc_str_tobuffer("MINFO", target));
        case 15:
                return (isc_str_tobuffer("MX", target));
        case 16:
                return (isc_str_tobuffer("TXT", target));
        case 17:
                return (isc_str_tobuffer("RP", target));
        case 18:
                return (isc_str_tobuffer("AFSDB", target));
        case 19:
                return (isc_str_tobuffer("X25", target));
        case 20:
                return (isc_str_tobuffer("ISDN", target));
        case 21:
                return (isc_str_tobuffer("RT", target));
        case 22:
                return (isc_str_tobuffer("NSAP", target));
        case 23:
                return (isc_str_tobuffer("NSAP-PTR", target));
        case 24:
                return (isc_str_tobuffer("SIG", target));
        case 25:
                return (isc_str_tobuffer("KEY", target));
        case 26:
                return (isc_str_tobuffer("PX", target));
        case 27:
                return (isc_str_tobuffer("GPOS", target));
        case 28:
                return (isc_str_tobuffer("AAAA", target));
        case 29:
                return (isc_str_tobuffer("LOC", target));
        case 30:
                return (isc_str_tobuffer("NXT", target));
        case 31:
                return (isc_str_tobuffer("EID", target));
        case 32:
                return (isc_str_tobuffer("NIMLOC", target));
        case 33:
                return (isc_str_tobuffer("SRV", target));
        case 34:
                return (isc_str_tobuffer("ATMA", target));
        case 35:
                return (isc_str_tobuffer("NAPTR", target));
        case 36:
                return (isc_str_tobuffer("KX", target));
        case 37:
                return (isc_str_tobuffer("CERT", target));
        case 38:
                return (isc_str_tobuffer("A6", target));
        case 39:
                return (isc_str_tobuffer("DNAME", target));
        case 40:
                return (isc_str_tobuffer("SINK", target));
        case 41:
                return (isc_str_tobuffer("OPT", target));
        case 42:
                return (isc_str_tobuffer("APL", target));
        case 43:
                return (isc_str_tobuffer("DS", target));
        case 44:
                return (isc_str_tobuffer("SSHFP", target));
        case 45:
                return (isc_str_tobuffer("IPSECKEY", target));
        case 46:
                return (isc_str_tobuffer("RRSIG", target));
        case 47:
                return (isc_str_tobuffer("NSEC", target));
        case 48:
                return (isc_str_tobuffer("DNSKEY", target));
        case 49:
                return (isc_str_tobuffer("DHCID", target));
        case 50:
                return (isc_str_tobuffer("NSEC3", target));
        case 51:
                return (isc_str_tobuffer("NSEC3PARAM", target));
        case 52:
                return (isc_str_tobuffer("TLSA", target));
        case 53:
                return (isc_str_tobuffer("SMIMEA", target));
        case 55:
                return (isc_str_tobuffer("HIP", target));
        case 56:
                return (isc_str_tobuffer("NINFO", target));
        case 57:
                return (isc_str_tobuffer("RKEY", target));
        case 58:
                return (isc_str_tobuffer("TALINK", target));
        case 59:
                return (isc_str_tobuffer("CDS", target));
        case 60:
                return (isc_str_tobuffer("CDNSKEY", target));
        case 61:
                return (isc_str_tobuffer("OPENPGPKEY", target));
        case 62:
                return (isc_str_tobuffer("CSYNC", target));
        case 63:
                return (isc_str_tobuffer("ZONEMD", target));
        case 64:
                return (isc_str_tobuffer("SVCB", target));
        case 65:
                return (isc_str_tobuffer("HTTPS", target));
        case 99:
                return (isc_str_tobuffer("SPF", target));
        case 100:
                return (isc_str_tobuffer("UINFO", target));
        case 101:
                return (isc_str_tobuffer("UID", target));
        case 102:
                return (isc_str_tobuffer("GID", target));
        case 103:
                return (isc_str_tobuffer("UNSPEC", target));
        case 104:
                return (isc_str_tobuffer("NID", target));
        case 105:
                return (isc_str_tobuffer("L32", target));
        case 106:
                return (isc_str_tobuffer("L64", target));
        case 107:
                return (isc_str_tobuffer("LP", target));
        case 108:
                return (isc_str_tobuffer("EUI48", target));
        case 109:
                return (isc_str_tobuffer("EUI64", target));
        case 249:
                return (isc_str_tobuffer("TKEY", target));
        case 250:
                return (isc_str_tobuffer("TSIG", target));
        case 251:
                return (isc_str_tobuffer("IXFR", target));
        case 252:
                return (isc_str_tobuffer("AXFR", target));
        case 253:
                return (isc_str_tobuffer("MAILB", target));
        case 254:
                return (isc_str_tobuffer("MAILA", target));
        case 255:
                return (isc_str_tobuffer("ANY", target));
        case 256:
                return (isc_str_tobuffer("URI", target));
        case 257:
                return (isc_str_tobuffer("CAA", target));
        case 258:
                return (isc_str_tobuffer("AVC", target));
        case 259:
                return (isc_str_tobuffer("DOA", target));
        case 261:
                return (isc_str_tobuffer("RESINFO", target));
        case 32768:
                return (isc_str_tobuffer("TA", target));
        case 32769:
                return (isc_str_tobuffer("DLV", target));
        default:
                snprintf(buf, sizeof(buf), "TYPE%u", type);
                return (isc_str_tobuffer(buf, target));
        }
}

void
dns_rdatatype_format(dns_rdatatype_t rdtype,
                     char *array, unsigned int size)
{
        isc_result_t result;
        isc_buffer_t buf;

        if (size == 0U)
                return;

        isc_buffer_init(&buf, array, size);
        result = dns_rdatatype_totext(rdtype, &buf);
        /*
         * Null terminate.
         */
        if (result == ISC_R_SUCCESS) {
                if (isc_buffer_availablelength(&buf) >= 1)
                        isc_buffer_putuint8(&buf, 0);
                else
                        result = ISC_R_NOSPACE;
        }
        if (result != ISC_R_SUCCESS)
                strlcpy(array, "<unknown>", size);
}

/*
 * Private function.
 */

static unsigned int
name_length(dns_name_t *name) {
        return (name->length);
}

static isc_result_t
txt_totext(isc_region_t *source, int quote, isc_buffer_t *target) {
        unsigned int tl;
        unsigned int n;
        unsigned char *sp;
        char *tp;
        isc_region_t region;

        isc_buffer_availableregion(target, &region);
        sp = source->base;
        tp = (char *)region.base;
        tl = region.length;

        n = *sp++;

        REQUIRE(n + 1 <= source->length);
        if (n == 0U)
                REQUIRE(quote);

        if (quote) {
                if (tl < 1)
                        return (ISC_R_NOSPACE);
                *tp++ = '"';
                tl--;
        }
        while (n--) {
                /*
                 * \DDD space (0x20) if not quoting.
                 */
                if (*sp < (quote ? 0x20 : 0x21) || *sp >= 0x7f) {
                        if (tl < 4)
                                return (ISC_R_NOSPACE);
                        *tp++ = 0x5c;
                        *tp++ = 0x30 + ((*sp / 100) % 10);
                        *tp++ = 0x30 + ((*sp / 10) % 10);
                        *tp++ = 0x30 + (*sp % 10);
                        sp++;
                        tl -= 4;
                        continue;
                }
                /*
                 * Escape double quote and backslash.  If we are not
                 * enclosing the string in double quotes also escape
                 * at sign and semicolon.
                 */
                if (*sp == 0x22 || *sp == 0x5c ||
                    (!quote && (*sp == 0x40 || *sp == 0x3b))) {
                        if (tl < 2)
                                return (ISC_R_NOSPACE);
                        *tp++ = '\\';
                        tl--;
                }
                if (tl < 1)
                        return (ISC_R_NOSPACE);
                *tp++ = *sp++;
                tl--;
        }
        if (quote) {
                if (tl < 1)
                        return (ISC_R_NOSPACE);
                *tp++ = '"';
                tl--;
                POST(tl);
        }
        isc_buffer_add(target, (unsigned int)(tp - (char *)region.base));
        isc_region_consume(source, *source->base + 1);
        return (ISC_R_SUCCESS);
}

static isc_result_t
txt_fromwire(isc_buffer_t *source, isc_buffer_t *target) {
        unsigned int n;
        isc_region_t sregion;
        isc_region_t tregion;

        isc_buffer_activeregion(source, &sregion);
        if (sregion.length == 0)
                return (ISC_R_UNEXPECTEDEND);
        n = *sregion.base + 1;
        if (n > sregion.length)
                return (ISC_R_UNEXPECTEDEND);

        isc_buffer_availableregion(target, &tregion);
        if (n > tregion.length)
                return (ISC_R_NOSPACE);

        if (tregion.base != sregion.base)
                memmove(tregion.base, sregion.base, n);
        isc_buffer_forward(source, n);
        isc_buffer_add(target, n);
        return (ISC_R_SUCCESS);
}

/*
 * Conversion of TXT-like rdata fields without length limits.
 */
static isc_result_t
multitxt_totext(isc_region_t *source, isc_buffer_t *target) {
        unsigned int tl;
        unsigned int n0, n;
        unsigned char *sp;
        char *tp;
        isc_region_t region;

        isc_buffer_availableregion(target, &region);
        sp = source->base;
        tp = (char *)region.base;
        tl = region.length;

        if (tl < 1)
                return (ISC_R_NOSPACE);
        *tp++ = '"';
        tl--;
        do {
                n = source->length;
                n0 = source->length - 1;

                while (n--) {
                        if (*sp < 0x20 || *sp >= 0x7f) {
                                if (tl < 4)
                                        return (ISC_R_NOSPACE);
                                *tp++ = 0x5c;
                                *tp++ = 0x30 + ((*sp / 100) % 10);
                                *tp++ = 0x30 + ((*sp / 10) % 10);
                                *tp++ = 0x30 + (*sp % 10);
                                sp++;
                                tl -= 4;
                                continue;
                        }
                        /* double quote, backslash */
                        if (*sp == 0x22 || *sp == 0x5c) {
                                if (tl < 2)
                                        return (ISC_R_NOSPACE);
                                *tp++ = '\\';
                                tl--;
                        }
                        if (tl < 1)
                                return (ISC_R_NOSPACE);
                        *tp++ = *sp++;
                        tl--;
                }
                isc_region_consume(source, n0 + 1);
        } while (source->length != 0);
        if (tl < 1)
                return (ISC_R_NOSPACE);
        *tp++ = '"';
        tl--;
        POST(tl);
        isc_buffer_add(target, (unsigned int)(tp - (char *)region.base));
        return (ISC_R_SUCCESS);
}

static int
name_prefix(dns_name_t *name, dns_name_t *origin, dns_name_t *target) {
        int l1, l2;

        if (origin == NULL)
                goto return_false;

        if (dns_name_compare(origin, dns_rootname) == 0)
                goto return_false;

        if (!dns_name_issubdomain(name, origin))
                goto return_false;

        l1 = dns_name_countlabels(name);
        l2 = dns_name_countlabels(origin);

        if (l1 == l2)
                goto return_false;

        /* Master files should be case preserving. */
        dns_name_getlabelsequence(name, l1 - l2, l2, target);
        if (!dns_name_caseequal(origin, target))
                goto return_false;

        dns_name_getlabelsequence(name, 0, l1 - l2, target);
        return (1);

return_false:
        *target = *name;
        return (0);
}

static isc_result_t
inet_totext(int af, isc_region_t *src, isc_buffer_t *target) {
        char tmpbuf[64];

        /* Note - inet_ntop doesn't do size checking on its input. */
        if (inet_ntop(af, src->base, tmpbuf, sizeof(tmpbuf)) == NULL)
                return (ISC_R_NOSPACE);
        if (strlen(tmpbuf) > isc_buffer_availablelength(target))
                return (ISC_R_NOSPACE);
        isc_buffer_putstr(target, tmpbuf);
        return (ISC_R_SUCCESS);
}

static int
buffer_empty(isc_buffer_t *source) {
        return((source->current == source->active) ? 1 : 0);
}

static isc_result_t
uint32_tobuffer(uint32_t value, isc_buffer_t *target) {
        isc_region_t region;

        isc_buffer_availableregion(target, &region);
        if (region.length < 4)
                return (ISC_R_NOSPACE);
        isc_buffer_putuint32(target, value);
        return (ISC_R_SUCCESS);
}

static isc_result_t
uint16_tobuffer(uint32_t value, isc_buffer_t *target) {
        isc_region_t region;

        if (value > 0xffff)
                return (ISC_R_RANGE);
        isc_buffer_availableregion(target, &region);
        if (region.length < 2)
                return (ISC_R_NOSPACE);
        isc_buffer_putuint16(target, (uint16_t)value);
        return (ISC_R_SUCCESS);
}

static isc_result_t
name_tobuffer(dns_name_t *name, isc_buffer_t *target) {
        isc_region_t r;
        dns_name_toregion(name, &r);
        return (isc_buffer_copyregion(target, &r));
}

static uint32_t
uint32_fromregion(isc_region_t *region) {
        uint32_t value;

        REQUIRE(region->length >= 4);
        value = region->base[0] << 24;
        value |= region->base[1] << 16;
        value |= region->base[2] << 8;
        value |= region->base[3];
        return(value);
}

static uint16_t
uint16_fromregion(isc_region_t *region) {

        REQUIRE(region->length >= 2);

        return ((region->base[0] << 8) | region->base[1]);
}

static uint8_t
uint8_fromregion(isc_region_t *region) {

        REQUIRE(region->length >= 1);

        return (region->base[0]);
}

static uint8_t
uint8_consume_fromregion(isc_region_t *region) {
        uint8_t r = uint8_fromregion(region);

        isc_region_consume(region, 1);
        return r;
}

static const char atob_digits[86] =
        "!\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`" \
        "abcdefghijklmnopqrstu";
/*
 * Subroutines to convert between 8 bit binary bytes and printable ASCII.
 * Computes the number of bytes, and three kinds of simple checksums.
 * Incoming bytes are collected into 32-bit words, then printed in base 85:
 *      exp(85,5) > exp(2,32)
 * The ASCII characters used are between '!' and 'u';
 * 'z' encodes 32-bit zero; 'x' is used to mark the end of encoded data.
 *
 * Originally by Paul Rutter (philabs!per) and Joe Orost (petsd!joe) for
 * the atob/btoa programs, released with the compress program, in mod.sources.
 * Modified by Mike Schwartz 8/19/86 for use in BIND.
 * Modified to be re-entrant 3/2/99.
 */

struct state {
        int32_t Ceor;
        int32_t Csum;
        int32_t Crot;
        int32_t word;
        int32_t bcount;
};

#define Ceor state->Ceor
#define Csum state->Csum
#define Crot state->Crot
#define word state->word
#define bcount state->bcount

static isc_result_t     byte_btoa(int c, isc_buffer_t *, struct state *state);

/*
 * Encode binary byte c into ASCII representation and place into *bufp,
 * advancing bufp.
 */
static isc_result_t
byte_btoa(int c, isc_buffer_t *target, struct state *state) {
        isc_region_t tr;

        isc_buffer_availableregion(target, &tr);
        Ceor ^= c;
        Csum += c;
        Csum += 1;
        if ((Crot & 0x80000000)) {
                Crot <<= 1;
                Crot += 1;
        } else {
                Crot <<= 1;
        }
        Crot += c;

        word <<= 8;
        word |= c;
        if (bcount == 3) {
                if (word == 0) {
                        if (tr.length < 1)
                                return (ISC_R_NOSPACE);
                        tr.base[0] = 'z';
                        isc_buffer_add(target, 1);
                } else {
                        register int tmp = 0;
                        register int32_t tmpword = word;

                        if (tmpword < 0) {
                                /*
                                 * Because some don't support u_long.
                                 */
                                tmp = 32;
                                tmpword -= (int32_t)(85 * 85 * 85 * 85 * 32);
                        }
                        if (tmpword < 0) {
                                tmp = 64;
                                tmpword -= (int32_t)(85 * 85 * 85 * 85 * 32);
                        }
                        if (tr.length < 5)
                                return (ISC_R_NOSPACE);
                        tr.base[0] = atob_digits[(tmpword /
                            (int32_t)(85 * 85 * 85 * 85)) + tmp];
                        tmpword %= (int32_t)(85 * 85 * 85 * 85);
                        tr.base[1] = atob_digits[tmpword / (85 * 85 * 85)];
                        tmpword %= (85 * 85 * 85);
                        tr.base[2] = atob_digits[tmpword / (85 * 85)];
                        tmpword %= (85 * 85);
                        tr.base[3] = atob_digits[tmpword / 85];
                        tmpword %= 85;
                        tr.base[4] = atob_digits[tmpword];
                        isc_buffer_add(target, 5);
                }
                bcount = 0;
        } else {
                bcount += 1;
        }
        return (ISC_R_SUCCESS);
}

/*
 * Encode the binary data from inbuf, of length inbuflen, into a
 * target.  Return success/failure status
 */
static isc_result_t
btoa_totext(unsigned char *inbuf, int inbuflen, isc_buffer_t *target) {
        int inc;
        struct state statebuf, *state = &statebuf;
        char buf[sizeof("x 2000000000 ffffffff ffffffff ffffffff")];

        Ceor = Csum = Crot = word = bcount = 0;
        for (inc = 0; inc < inbuflen; inbuf++, inc++)
                RETERR(byte_btoa(*inbuf, target, state));

        while (bcount != 0)
                RETERR(byte_btoa(0, target, state));

        /*
         * Put byte count and checksum information at end of buffer,
         * delimited by 'x'
         */
        snprintf(buf, sizeof(buf), "x %d %x %x %x", inbuflen, Ceor, Csum, Crot);
        return (isc_str_tobuffer(buf, target));
}

dns_rdatatype_t
dns_rdata_covers(dns_rdata_t *rdata) {
        if (rdata->type == dns_rdatatype_rrsig)
                return (covers_rrsig(rdata));
        return (covers_sig(rdata));
}