rdata.c

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/*
 * Copyright (C) 2004-2015  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2003  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.
 */

/* $Id$ */

/*! \file */

#include <config.h>
#include <ctype.h>

#include <isc/base64.h>
#include <isc/hex.h>
#include <isc/lex.h>
#include <isc/mem.h>
#include <isc/parseint.h>
#include <isc/print.h>
#include <isc/string.h>
#include <isc/stdlib.h>
#include <isc/util.h>

#include <dns/callbacks.h>
#include <dns/cert.h>
#include <dns/compress.h>
#include <dns/dsdigest.h>
#include <dns/enumtype.h>
#include <dns/keyflags.h>
#include <dns/keyvalues.h>
#include <dns/message.h>
#include <dns/rcode.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/secalg.h>
#include <dns/secproto.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 RETTOK(x) \
        do { \
                isc_result_t _r = (x); \
                if (_r != ISC_R_SUCCESS) { \
                        isc_lex_ungettoken(lexer, &token); \
                        return (_r); \
                } \
        } while (0)

#define DNS_AS_STR(t) ((t).value.as_textregion.base)

#define ARGS_FROMTEXT   int rdclass, dns_rdatatype_t type, \
                        isc_lex_t *lexer, dns_name_t *origin, \
                        unsigned int options, isc_buffer_t *target, \
                        dns_rdatacallbacks_t *callbacks

#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_COMPARE    const dns_rdata_t *rdata1, const dns_rdata_t *rdata2

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

#define ARGS_TOSTRUCT   dns_rdata_t *rdata, void *target, isc_mem_t *mctx

#define ARGS_FREESTRUCT void *source

#define ARGS_ADDLDATA   dns_rdata_t *rdata, dns_additionaldatafunc_t add, \
                        void *arg

#define ARGS_DIGEST     dns_rdata_t *rdata, dns_digestfunc_t digest, void *arg

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

#define ARGS_CHECKNAMES dns_rdata_t *rdata, dns_name_t *owner, dns_name_t *bad


/*%
 * 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;

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

static isc_result_t
txt_fromtext(isc_textregion_t *source, 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 isc_result_t
multitxt_fromtext(isc_textregion_t *source, isc_buffer_t *target);

static isc_boolean_t
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
str_totext(const char *source, isc_buffer_t *target);

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

static isc_boolean_t
buffer_empty(isc_buffer_t *source);

static void
buffer_fromregion(isc_buffer_t *buffer, isc_region_t *region);

static isc_result_t
uint32_tobuffer(isc_uint32_t, isc_buffer_t *target);

static isc_result_t
uint16_tobuffer(isc_uint32_t, isc_buffer_t *target);

static isc_result_t
uint8_tobuffer(isc_uint32_t, isc_buffer_t *target);

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

static isc_uint32_t
uint32_fromregion(isc_region_t *region);

static isc_uint16_t
uint16_fromregion(isc_region_t *region);

static isc_uint8_t
uint8_fromregion(isc_region_t *region);

static isc_uint8_t
uint8_consume_fromregion(isc_region_t *region);

static isc_result_t
mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length);

static int
hexvalue(char value);

static int
decvalue(char value);

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

static isc_result_t
atob_tobuffer(isc_lex_t *lexer, isc_buffer_t *target);

static void
default_fromtext_callback(dns_rdatacallbacks_t *callbacks, const char *, ...)
     ISC_FORMAT_PRINTF(2, 3);

static void
fromtext_error(void (*callback)(dns_rdatacallbacks_t *, const char *, ...),
               dns_rdatacallbacks_t *callbacks, const char *name,
               unsigned long line, isc_token_t *token, isc_result_t result);

static void
fromtext_warneof(isc_lex_t *lexer, dns_rdatacallbacks_t *callbacks);

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

static void
warn_badname(dns_name_t *name, isc_lex_t *lexer,
             dns_rdatacallbacks_t *callbacks);

static void
warn_badmx(isc_token_t *token, isc_lex_t *lexer,
           dns_rdatacallbacks_t *callbacks);

static isc_uint16_t
uint16_consume_fromregion(isc_region_t *region);

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

/*% INT16 Size */
#define NS_INT16SZ      2
/*% IPv6 Address Size */
#define NS_LOCATORSZ    8

/*%
 *      convert presentation level address to network order binary form.
 * \return
 *      1 if `src' is a valid [RFC1884 2.2] address, else 0.
 * \note
 *      (1) does not touch `dst' unless it's returning 1.
 */
static inline int
locator_pton(const char *src, unsigned char *dst) {
        static const char xdigits_l[] = "0123456789abcdef",
                          xdigits_u[] = "0123456789ABCDEF";
        unsigned char tmp[NS_LOCATORSZ];
        unsigned char *tp = tmp, *endp;
        const char *xdigits;
        int ch, seen_xdigits;
        unsigned int val;

        memset(tp, '\0', NS_LOCATORSZ);
        endp = tp + NS_LOCATORSZ;
        seen_xdigits = 0;
        val = 0;
        while ((ch = *src++) != '\0') {
                const char *pch;

                pch = strchr((xdigits = xdigits_l), ch);
                if (pch == NULL)
                        pch = strchr((xdigits = xdigits_u), ch);
                if (pch != NULL) {
                        val <<= 4;
                        val |= (pch - xdigits);
                        if (++seen_xdigits > 4)
                                return (0);
                        continue;
                }
                if (ch == ':') {
                        if (!seen_xdigits)
                                return (0);
                        if (tp + NS_INT16SZ > endp)
                                return (0);
                        *tp++ = (unsigned char) (val >> 8) & 0xff;
                        *tp++ = (unsigned char) val & 0xff;
                        seen_xdigits = 0;
                        val = 0;
                        continue;
                }
                return (0);
        }
        if (seen_xdigits) {
                if (tp + NS_INT16SZ > endp)
                        return (0);
                *tp++ = (unsigned char) (val >> 8) & 0xff;
                *tp++ = (unsigned char) val & 0xff;
        }
        if (tp != endp)
                return (0);
        memmove(dst, tmp, NS_LOCATORSZ);
        return (1);
}

static inline int
getquad(const void *src, struct in_addr *dst,
        isc_lex_t *lexer, dns_rdatacallbacks_t *callbacks)
{
        int result;
        struct in_addr *tmp;

        result = inet_aton(src, dst);
        if (result == 1 && callbacks != NULL &&
            inet_pton(AF_INET, src, &tmp) != 1) {
                const char *name = isc_lex_getsourcename(lexer);
                if (name == NULL)
                        name = "UNKNOWN";
                (*callbacks->warn)(callbacks, "%s:%lu: \"%s\" "
                                   "is not a decimal dotted quad", name,
                                   isc_lex_getsourceline(lexer), src);
        }
        return (result);
}

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

        if (mctx != NULL)
                return (dns_name_dup(source, mctx, target));
        dns_name_clone(source, target);
        return (ISC_R_SUCCESS);
}

static inline void *
mem_maybedup(isc_mem_t *mctx, void *source, size_t length) {
        void *new;

        if (mctx == NULL)
                return (source);
        new = isc_mem_allocate(mctx, length);
        if (new != NULL)
                memmove(new, source, length);

        return (new);
}

static const char hexdigits[] = "0123456789abcdef";
static const char decdigits[] = "0123456789";

#include "code.h"

#define META 0x0001
#define RESERVED 0x0002

/***
 *** 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;
}


/***
 *** Comparisons
 ***/

int
dns_rdata_compare(const dns_rdata_t *rdata1, const dns_rdata_t *rdata2) {
        int result = 0;
        isc_boolean_t use_default = ISC_FALSE;

        REQUIRE(rdata1 != NULL);
        REQUIRE(rdata2 != NULL);
        REQUIRE(rdata1->length == 0 || rdata1->data != NULL);
        REQUIRE(rdata2->length == 0 || rdata2->data != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata1));
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata2));

        if (rdata1->rdclass != rdata2->rdclass)
                return (rdata1->rdclass < rdata2->rdclass ? -1 : 1);

        if (rdata1->type != rdata2->type)
                return (rdata1->type < rdata2->type ? -1 : 1);

        COMPARESWITCH

        if (use_default) {
                isc_region_t r1;
                isc_region_t r2;

                dns_rdata_toregion(rdata1, &r1);
                dns_rdata_toregion(rdata2, &r2);
                result = isc_region_compare(&r1, &r2);
        }
        return (result);
}

int
dns_rdata_casecompare(const dns_rdata_t *rdata1, const dns_rdata_t *rdata2) {
        int result = 0;
        isc_boolean_t use_default = ISC_FALSE;

        REQUIRE(rdata1 != NULL);
        REQUIRE(rdata2 != NULL);
        REQUIRE(rdata1->length == 0 || rdata1->data != NULL);
        REQUIRE(rdata2->length == 0 || rdata2->data != NULL);
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata1));
        REQUIRE(DNS_RDATA_VALIDFLAGS(rdata2));

        if (rdata1->rdclass != rdata2->rdclass)
                return (rdata1->rdclass < rdata2->rdclass ? -1 : 1);

        if (rdata1->type != rdata2->type)
                return (rdata1->type < rdata2->type ? -1 : 1);

        CASECOMPARESWITCH

        if (use_default) {
                isc_region_t r1;
                isc_region_t r2;

                dns_rdata_toregion(rdata1, &r1);
                dns_rdata_toregion(rdata2, &r2);
                result = isc_region_compare(&r1, &r2);
        }
        return (result);
}

/***
 *** 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;
        isc_boolean_t use_default = ISC_FALSE;
        isc_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;
        isc_boolean_t use_default = ISC_FALSE;
        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, (isc_uint16_t)target->used);
        }
        return (result);
}

/*
 * If the binary data in 'src' is valid uncompressed wire format
 * rdata of class 'rdclass' and type 'type', return ISC_R_SUCCESS
 * and copy the validated rdata to 'dest'.  Otherwise return an error.
 */
static isc_result_t
rdata_validate(isc_buffer_t *src, isc_buffer_t *dest, dns_rdataclass_t rdclass,
            dns_rdatatype_t type)
{
        dns_decompress_t dctx;
        isc_result_t result;

        dns_decompress_init(&dctx, -1, DNS_DECOMPRESS_NONE);
        isc_buffer_setactive(src, isc_buffer_usedlength(src));
        result = dns_rdata_fromwire(NULL, rdclass, type, src, &dctx, 0, dest);
        dns_decompress_invalidate(&dctx);

        return (result);
}

static isc_result_t
unknown_fromtext(dns_rdataclass_t rdclass, dns_rdatatype_t type,
                 isc_lex_t *lexer, isc_mem_t *mctx, isc_buffer_t *target)
{
        isc_result_t result;
        isc_buffer_t *buf = NULL;
        isc_token_t token;

        if (type == 0 || dns_rdatatype_ismeta(type))
                return (DNS_R_METATYPE);

        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_number,
                                        ISC_FALSE));
        if (token.value.as_ulong > 65535U)
                return (ISC_R_RANGE);
        result = isc_buffer_allocate(mctx, &buf, token.value.as_ulong);
        if (result != ISC_R_SUCCESS)
                return (result);

        result = isc_hex_tobuffer(lexer, buf,
                                  (unsigned int)token.value.as_ulong);
        if (result != ISC_R_SUCCESS)
               goto failure;
        if (isc_buffer_usedlength(buf) != token.value.as_ulong) {
                result = ISC_R_UNEXPECTEDEND;
                goto failure;
        }

        if (dns_rdatatype_isknown(type)) {
                result = rdata_validate(buf, target, rdclass, type);
        } else {
                isc_region_t r;
                isc_buffer_usedregion(buf, &r);
                result = isc_buffer_copyregion(target, &r);
        }
        if (result != ISC_R_SUCCESS)
                goto failure;

        isc_buffer_free(&buf);
        return (ISC_R_SUCCESS);

 failure:
        isc_buffer_free(&buf);
        return (result);
}

isc_result_t
dns_rdata_fromtext(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
                   dns_rdatatype_t type, isc_lex_t *lexer,
                   dns_name_t *origin, unsigned int options, isc_mem_t *mctx,
                   isc_buffer_t *target, dns_rdatacallbacks_t *callbacks)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_region_t region;
        isc_buffer_t st;
        isc_token_t token;
        unsigned int lexoptions = ISC_LEXOPT_EOL | ISC_LEXOPT_EOF |
                                  ISC_LEXOPT_DNSMULTILINE | ISC_LEXOPT_ESCAPE;
        char *name;
        unsigned long line;
        void (*callback)(dns_rdatacallbacks_t *, const char *, ...);
        isc_result_t tresult;
        unsigned int length;
        isc_boolean_t unknown;

        REQUIRE(origin == NULL || dns_name_isabsolute(origin) == ISC_TRUE);
        if (rdata != NULL) {
                REQUIRE(DNS_RDATA_INITIALIZED(rdata));
                REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
        }
        if (callbacks != NULL) {
                REQUIRE(callbacks->warn != NULL);
                REQUIRE(callbacks->error != NULL);
        }

        st = *target;

        if (callbacks != NULL)
                callback = callbacks->error;
        else
                callback = default_fromtext_callback;

        result = isc_lex_getmastertoken(lexer, &token, isc_tokentype_qstring,
                                        ISC_FALSE);
        if (result != ISC_R_SUCCESS) {
                name = isc_lex_getsourcename(lexer);
                line = isc_lex_getsourceline(lexer);
                fromtext_error(callback, callbacks, name, line, NULL, result);
                return (result);
        }

        unknown = ISC_FALSE;
        if (token.type == isc_tokentype_string &&
            strcmp(DNS_AS_STR(token), "\\#") == 0) {
                /*
                 * If this is a TXT record '\#' could be a escaped '#'.
                 * Look to see if the next token is a number and if so
                 * treat it as a unknown record format.
                 */
                if (type == dns_rdatatype_txt) {
                        result = isc_lex_getmastertoken(lexer, &token,
                                                        isc_tokentype_number,
                                                        ISC_FALSE);
                        if (result == ISC_R_SUCCESS)
                                isc_lex_ungettoken(lexer, &token);
                }

                if (result == ISC_R_SUCCESS) {
                        unknown = ISC_TRUE;
                        result = unknown_fromtext(rdclass, type, lexer,
                                                  mctx, target);
                } else
                        options |= DNS_RDATA_UNKNOWNESCAPE;
        } else
                isc_lex_ungettoken(lexer, &token);

        if (!unknown)
                FROMTEXTSWITCH

        /*
         * Consume to end of line / file.
         * If not at end of line initially set error code.
         * Call callback via fromtext_error once if there was an error.
         */
        do {
                name = isc_lex_getsourcename(lexer);
                line = isc_lex_getsourceline(lexer);
                tresult = isc_lex_gettoken(lexer, lexoptions, &token);
                if (tresult != ISC_R_SUCCESS) {
                        if (result == ISC_R_SUCCESS)
                                result = tresult;
                        if (callback != NULL)
                                fromtext_error(callback, callbacks, name,
                                               line, NULL, result);
                        break;
                } else if (token.type != isc_tokentype_eol &&
                           token.type != isc_tokentype_eof) {
                        if (result == ISC_R_SUCCESS)
                                result = DNS_R_EXTRATOKEN;
                        if (callback != NULL) {
                                fromtext_error(callback, callbacks, name,
                                               line, &token, result);
                                callback = NULL;
                        }
                } else if (result != ISC_R_SUCCESS && callback != NULL) {
                        fromtext_error(callback, callbacks, name, line,
                                       &token, result);
                        break;
                } else {
                        if (token.type == isc_tokentype_eof)
                                fromtext_warneof(lexer, callbacks);
                        break;
                }
        } while (1);

        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);
}

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 = str_totext(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 = str_totext(buf, target);
        if (result != ISC_R_SUCCESS)
                return (result);

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

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

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

        TOTEXTSWITCH

        if (use_default)
                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(dns_rdata_t *rdata, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type, void *source,
                     isc_buffer_t *target)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_buffer_t st;
        isc_region_t region;
        isc_boolean_t use_default = ISC_FALSE;
        unsigned int length;

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

        st = *target;

        FROMSTRUCTSWITCH

        if (use_default)
                (void)NULL;

        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(dns_rdata_t *rdata, void *target, isc_mem_t *mctx) {
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_boolean_t use_default = ISC_FALSE;

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

        TOSTRUCTSWITCH

        if (use_default)
                (void)NULL;

        return (result);
}

void
dns_rdata_freestruct(void *source) {
        dns_rdatacommon_t *common = source;
        REQUIRE(source != NULL);

        FREESTRUCTSWITCH
}

isc_result_t
dns_rdata_additionaldata(dns_rdata_t *rdata, dns_additionaldatafunc_t add,
                         void *arg)
{
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_boolean_t use_default = ISC_FALSE;

        /*
         * Call 'add' for each name and type from 'rdata' which is subject to
         * additional section processing.
         */

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

        ADDITIONALDATASWITCH

        /* No additional processing for unknown types */
        if (use_default)
                result = ISC_R_SUCCESS;

        return (result);
}

isc_result_t
dns_rdata_digest(dns_rdata_t *rdata, dns_digestfunc_t digest, void *arg) {
        isc_result_t result = ISC_R_NOTIMPLEMENTED;
        isc_boolean_t use_default = ISC_FALSE;
        isc_region_t r;

        /*
         * Send 'rdata' in DNSSEC canonical form to 'digest'.
         */

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

        DIGESTSWITCH

        if (use_default) {
                dns_rdata_toregion(rdata, &r);
                result = (digest)(arg, &r);
        }

        return (result);
}

isc_boolean_t
dns_rdata_checkowner(dns_name_t *name, dns_rdataclass_t rdclass,
                     dns_rdatatype_t type, isc_boolean_t wildcard)
{
        isc_boolean_t result;

        CHECKOWNERSWITCH
        return (result);
}

isc_boolean_t
dns_rdata_checknames(dns_rdata_t *rdata, dns_name_t *owner, dns_name_t *bad)
{
        isc_boolean_t result;

        CHECKNAMESSWITCH
        return (result);
}

unsigned int
dns_rdatatype_attributes(dns_rdatatype_t type)
{
        RDATATYPE_ATTRIBUTE_SW
        return (DNS_RDATATYPEATTR_UNKNOWN);
}

isc_result_t
dns_rdatatype_fromtext(dns_rdatatype_t *typep, isc_textregion_t *source) {
        unsigned int hash;
        unsigned int n;
        unsigned char a, b;

        n = source->length;

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

        a = tolower((unsigned char)source->base[0]);
        b = tolower((unsigned char)source->base[n - 1]);

        hash = ((a + n) * b) % 256;

        /*
         * This switch block is inlined via \#define, and will use "return"
         * to return a result to the caller if it is a valid (known)
         * rdatatype name.
         */
        RDATATYPE_FROMTEXT_SW(hash, source->base, n, typep);

        if (source->length > 4 && source->length < (4 + sizeof("65000")) &&
            strncasecmp("type", source->base, 4) == 0) {
                char buf[sizeof("65000")];
                char *endp;
                unsigned int val;

                strncpy(buf, source->base + 4, source->length - 4);
                buf[source->length - 4] = '\0';
                val = strtoul(buf, &endp, 10);
                if (*endp == '\0' && val <= 0xffff) {
                        *typep = (dns_rdatatype_t)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")];

        RDATATYPE_TOTEXT_SW
        snprintf(buf, sizeof(buf), "TYPE%u", type);
        return (str_totext(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, isc_boolean_t 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 == ISC_TRUE);

        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--;
        }
        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_fromtext(isc_textregion_t *source, isc_buffer_t *target) {
        isc_region_t tregion;
        isc_boolean_t escape;
        unsigned int n, nrem;
        char *s;
        unsigned char *t;
        int d;
        int c;

        isc_buffer_availableregion(target, &tregion);
        s = source->base;
        n = source->length;
        t = tregion.base;
        nrem = tregion.length;
        escape = ISC_FALSE;
        if (nrem < 1)
                return (ISC_R_NOSPACE);
        /*
         * Length byte.
         */
        nrem--;
        t++;
        /*
         * Maximum text string length.
         */
        if (nrem > 255)
                nrem = 255;
        while (n-- != 0) {
                c = (*s++) & 0xff;
                if (escape && (d = decvalue((char)c)) != -1) {
                        c = d;
                        if (n == 0)
                                return (DNS_R_SYNTAX);
                        n--;
                        if ((d = decvalue(*s++)) != -1)
                                c = c * 10 + d;
                        else
                                return (DNS_R_SYNTAX);
                        if (n == 0)
                                return (DNS_R_SYNTAX);
                        n--;
                        if ((d = decvalue(*s++)) != -1)
                                c = c * 10 + d;
                        else
                                return (DNS_R_SYNTAX);
                        if (c > 255)
                                return (DNS_R_SYNTAX);
                } else if (!escape && c == '\\') {
                        escape = ISC_TRUE;
                        continue;
                }
                escape = ISC_FALSE;
                if (nrem == 0)
                        return ((tregion.length <= 256U) ?
                                ISC_R_NOSPACE : DNS_R_SYNTAX);
                *t++ = c;
                nrem--;
        }
        if (escape)
                return (DNS_R_SYNTAX);
        *tregion.base = (unsigned char)(t - tregion.base - 1);
        isc_buffer_add(target, *tregion.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, semi-colon, backslash */
                        if (*sp == 0x22 || *sp == 0x3b || *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--;
        isc_buffer_add(target, (unsigned int)(tp - (char *)region.base));
        return (ISC_R_SUCCESS);
}

static isc_result_t
multitxt_fromtext(isc_textregion_t *source, isc_buffer_t *target) {
        isc_region_t tregion;
        isc_boolean_t escape;
        unsigned int n, nrem;
        char *s;
        unsigned char *t0, *t;
        int d;
        int c;

        s = source->base;
        n = source->length;
        escape = ISC_FALSE;

        do {
                isc_buffer_availableregion(target, &tregion);
                t0 = t = tregion.base;
                nrem = tregion.length;
                if (nrem < 1)
                        return (ISC_R_NOSPACE);

                while (n != 0) {
                        --n;
                        c = (*s++) & 0xff;
                        if (escape && (d = decvalue((char)c)) != -1) {
                                c = d;
                                if (n == 0)
                                        return (DNS_R_SYNTAX);
                                n--;
                                if ((d = decvalue(*s++)) != -1)
                                        c = c * 10 + d;
                                else
                                        return (DNS_R_SYNTAX);
                                if (n == 0)
                                        return (DNS_R_SYNTAX);
                                n--;
                                if ((d = decvalue(*s++)) != -1)
                                        c = c * 10 + d;
                                else
                                        return (DNS_R_SYNTAX);
                                if (c > 255)
                                        return (DNS_R_SYNTAX);
                        } else if (!escape && c == '\\') {
                                escape = ISC_TRUE;
                                continue;
                        }
                        escape = ISC_FALSE;
                        *t++ = c;
                        nrem--;
                        if (nrem == 0)
                                break;
                }
                if (escape)
                        return (DNS_R_SYNTAX);

                isc_buffer_add(target, (unsigned int)(t - t0));
        } while (n != 0);
        return (ISC_R_SUCCESS);
}

static isc_boolean_t
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 (ISC_TRUE);

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

static isc_result_t
str_totext(const char *source, isc_buffer_t *target) {
        unsigned int l;
        isc_region_t region;

        isc_buffer_availableregion(target, &region);
        l = strlen(source);

        if (l > region.length)
                return (ISC_R_NOSPACE);

        memmove(region.base, source, l);
        isc_buffer_add(target, l);
        return (ISC_R_SUCCESS);
}

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 isc_boolean_t
buffer_empty(isc_buffer_t *source) {
        return((source->current == source->active) ? ISC_TRUE : ISC_FALSE);
}

static void
buffer_fromregion(isc_buffer_t *buffer, isc_region_t *region) {
        isc_buffer_init(buffer, region->base, region->length);
        isc_buffer_add(buffer, region->length);
        isc_buffer_setactive(buffer, region->length);
}

static isc_result_t
uint32_tobuffer(isc_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(isc_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, (isc_uint16_t)value);
        return (ISC_R_SUCCESS);
}

static isc_result_t
uint8_tobuffer(isc_uint32_t value, isc_buffer_t *target) {
        isc_region_t region;

        if (value > 0xff)
                return (ISC_R_RANGE);
        isc_buffer_availableregion(target, &region);
        if (region.length < 1)
                return (ISC_R_NOSPACE);
        isc_buffer_putuint8(target, (isc_uint8_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 isc_uint32_t
uint32_fromregion(isc_region_t *region) {
        isc_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 isc_uint16_t
uint16_consume_fromregion(isc_region_t *region) {
        isc_uint16_t r = uint16_fromregion(region);

        isc_region_consume(region, 2);
        return r;
}

static isc_uint16_t
uint16_fromregion(isc_region_t *region) {

        REQUIRE(region->length >= 2);

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

static isc_uint8_t
uint8_fromregion(isc_region_t *region) {

        REQUIRE(region->length >= 1);

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

static isc_uint8_t
uint8_consume_fromregion(isc_region_t *region) {
        isc_uint8_t r = uint8_fromregion(region);

        isc_region_consume(region, 1);
        return r;
}

static isc_result_t
mem_tobuffer(isc_buffer_t *target, void *base, unsigned int length) {
        isc_region_t tr;

        isc_buffer_availableregion(target, &tr);
        if (length > tr.length)
                return (ISC_R_NOSPACE);
        if (tr.base != base)
                memmove(tr.base, base, length);
        isc_buffer_add(target, length);
        return (ISC_R_SUCCESS);
}

static int
hexvalue(char value) {
        char *s;
        unsigned char c;

        c = (unsigned char)value;

        if (!isascii(c))
                return (-1);
        if (isupper(c))
                c = tolower(c);
        if ((s = strchr(hexdigits, c)) == NULL)
                return (-1);
        return (int)(s - hexdigits);
}

static int
decvalue(char value) {
        char *s;

        /*
         * isascii() is valid for full range of int values, no need to
         * mask or cast.
         */
        if (!isascii(value))
                return (-1);
        if ((s = strchr(decdigits, value)) == NULL)
                return (-1);
        return (int)(s - decdigits);
}

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 {
        isc_int32_t Ceor;
        isc_int32_t Csum;
        isc_int32_t Crot;
        isc_int32_t word;
        isc_int32_t bcount;
};

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

#define times85(x)      ((((((x<<2)+x)<<2)+x)<<2)+x)

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

/*
 * Decode ASCII-encoded byte c into binary representation and
 * place into *bufp, advancing bufp.
 */
static isc_result_t
byte_atob(int c, isc_buffer_t *target, struct state *state) {
        char *s;
        if (c == 'z') {
                if (bcount != 0)
                        return(DNS_R_SYNTAX);
                else {
                        RETERR(putbyte(0, target, state));
                        RETERR(putbyte(0, target, state));
                        RETERR(putbyte(0, target, state));
                        RETERR(putbyte(0, target, state));
                }
        } else if ((s = strchr(atob_digits, c)) != NULL) {
                if (bcount == 0) {
                        word = (isc_int32_t)(s - atob_digits);
                        ++bcount;
                } else if (bcount < 4) {
                        word = times85(word);
                        word += (isc_int32_t)(s - atob_digits);
                        ++bcount;
                } else {
                        word = times85(word);
                        word += (isc_int32_t)(s - atob_digits);
                        RETERR(putbyte((word >> 24) & 0xff, target, state));
                        RETERR(putbyte((word >> 16) & 0xff, target, state));
                        RETERR(putbyte((word >> 8) & 0xff, target, state));
                        RETERR(putbyte(word & 0xff, target, state));
                        word = 0;
                        bcount = 0;
                }
        } else
                return(DNS_R_SYNTAX);
        return(ISC_R_SUCCESS);
}

/*
 * Compute checksum info and place c into target.
 */
static isc_result_t
putbyte(int c, isc_buffer_t *target, struct state *state) {
        isc_region_t tr;

        Ceor ^= c;
        Csum += c;
        Csum += 1;
        if ((Crot & 0x80000000)) {
                Crot <<= 1;
                Crot += 1;
        } else {
                Crot <<= 1;
        }
        Crot += c;
        isc_buffer_availableregion(target, &tr);
        if (tr.length < 1)
                return (ISC_R_NOSPACE);
        tr.base[0] = c;
        isc_buffer_add(target, 1);
        return (ISC_R_SUCCESS);
}

/*
 * Read the ASCII-encoded data from inbuf, of length inbuflen, and convert
 * it into T_UNSPEC (binary data) in outbuf, not to exceed outbuflen bytes;
 * outbuflen must be divisible by 4.  (Note: this is because outbuf is filled
 * in 4 bytes at a time.  If the actual data doesn't end on an even 4-byte
 * boundary, there will be no problem...it will be padded with 0 bytes, and
 * numbytes will indicate the correct number of bytes.  The main point is
 * that since the buffer is filled in 4 bytes at a time, even if there is
 * not a full 4 bytes of data at the end, there has to be room to 0-pad the
 * data, so the buffer must be of size divisible by 4).  Place the number of
 * output bytes in numbytes, and return a failure/success status.
 */

static isc_result_t
atob_tobuffer(isc_lex_t *lexer, isc_buffer_t *target) {
        long oeor, osum, orot;
        struct state statebuf, *state= &statebuf;
        isc_token_t token;
        char c;
        char *e;

        Ceor = Csum = Crot = word = bcount = 0;

        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
                                      ISC_FALSE));
        while (token.value.as_textregion.length != 0) {
                if ((c = token.value.as_textregion.base[0]) == 'x') {
                        break;
                } else
                        RETERR(byte_atob(c, target, state));
                isc_textregion_consume(&token.value.as_textregion, 1);
        }

        /*
         * Number of bytes.
         */
        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_number,
                                      ISC_FALSE));
        if ((token.value.as_ulong % 4) != 0U)
                isc_buffer_subtract(target,  4 - (token.value.as_ulong % 4));

        /*
         * Checksum.
         */
        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
                                      ISC_FALSE));
        oeor = strtol(DNS_AS_STR(token), &e, 16);
        if (*e != 0)
                return (DNS_R_SYNTAX);

        /*
         * Checksum.
         */
        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
                                      ISC_FALSE));
        osum = strtol(DNS_AS_STR(token), &e, 16);
        if (*e != 0)
                return (DNS_R_SYNTAX);

        /*
         * Checksum.
         */
        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
                                      ISC_FALSE));
        orot = strtol(DNS_AS_STR(token), &e, 16);
        if (*e != 0)
                return (DNS_R_SYNTAX);

        if ((oeor != Ceor) || (osum != Csum) || (orot != Crot))
                return(DNS_R_BADCKSUM);
        return (ISC_R_SUCCESS);
}

/*
 * 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 isc_int32_t tmpword = word;

                    if (tmpword < 0) {
                           /*
                            * Because some don't support u_long.
                            */
                        tmp = 32;
                        tmpword -= (isc_int32_t)(85 * 85 * 85 * 85 * 32);
                    }
                    if (tmpword < 0) {
                        tmp = 64;
                        tmpword -= (isc_int32_t)(85 * 85 * 85 * 85 * 32);
                    }
                        if (tr.length < 5)
                                return (ISC_R_NOSPACE);
                        tr.base[0] = atob_digits[(tmpword /
                                              (isc_int32_t)(85 * 85 * 85 * 85))
                                                + tmp];
                        tmpword %= (isc_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 (str_totext(buf, target));
}


static void
default_fromtext_callback(dns_rdatacallbacks_t *callbacks, const char *fmt,
                          ...)
{
        va_list ap;

        UNUSED(callbacks);

        va_start(ap, fmt);
        vfprintf(stderr, fmt, ap);
        va_end(ap);
        fprintf(stderr, "\n");
}

static void
fromtext_warneof(isc_lex_t *lexer, dns_rdatacallbacks_t *callbacks) {
        if (isc_lex_isfile(lexer) && callbacks != NULL) {
                const char *name = isc_lex_getsourcename(lexer);
                if (name == NULL)
                        name = "UNKNOWN";
                (*callbacks->warn)(callbacks,
                                   "%s:%lu: file does not end with newline",
                                   name, isc_lex_getsourceline(lexer));
        }
}

static void
warn_badmx(isc_token_t *token, isc_lex_t *lexer,
           dns_rdatacallbacks_t *callbacks)
{
        const char *file;
        unsigned long line;

        if (lexer != NULL) {
                file = isc_lex_getsourcename(lexer);
                line = isc_lex_getsourceline(lexer);
                (*callbacks->warn)(callbacks, "%s:%u: warning: '%s': %s",
                                   file, line, DNS_AS_STR(*token),
                                   dns_result_totext(DNS_R_MXISADDRESS));
        }
}

static void
warn_badname(dns_name_t *name, isc_lex_t *lexer,
             dns_rdatacallbacks_t *callbacks)
{
        const char *file;
        unsigned long line;
        char namebuf[DNS_NAME_FORMATSIZE];

        if (lexer != NULL) {
                file = isc_lex_getsourcename(lexer);
                line = isc_lex_getsourceline(lexer);
                dns_name_format(name, namebuf, sizeof(namebuf));
                (*callbacks->warn)(callbacks, "%s:%u: warning: %s: %s",
                                   file, line, namebuf,
                                   dns_result_totext(DNS_R_BADNAME));
        }
}

static void
fromtext_error(void (*callback)(dns_rdatacallbacks_t *, const char *, ...),
               dns_rdatacallbacks_t *callbacks, const char *name,
               unsigned long line, isc_token_t *token, isc_result_t result)
{
        if (name == NULL)
                name = "UNKNOWN";

        if (token != NULL) {
                switch (token->type) {
                case isc_tokentype_eol:
                        (*callback)(callbacks, "%s: %s:%lu: near eol: %s",
                                    "dns_rdata_fromtext", name, line,
                                    dns_result_totext(result));
                        break;
                case isc_tokentype_eof:
                        (*callback)(callbacks, "%s: %s:%lu: near eof: %s",
                                    "dns_rdata_fromtext", name, line,
                                    dns_result_totext(result));
                        break;
                case isc_tokentype_number:
                        (*callback)(callbacks, "%s: %s:%lu: near %lu: %s",
                                    "dns_rdata_fromtext", name, line,
                                    token->value.as_ulong,
                                    dns_result_totext(result));
                        break;
                case isc_tokentype_string:
                case isc_tokentype_qstring:
                        (*callback)(callbacks, "%s: %s:%lu: near '%s': %s",
                                    "dns_rdata_fromtext", name, line,
                                    DNS_AS_STR(*token),
                                    dns_result_totext(result));
                        break;
                default:
                        (*callback)(callbacks, "%s: %s:%lu: %s",
                                    "dns_rdata_fromtext", name, line,
                                    dns_result_totext(result));
                        break;
                }
        } else {
                (*callback)(callbacks, "dns_rdata_fromtext: %s:%lu: %s",
                            name, line, dns_result_totext(result));
        }
}

dns_rdatatype_t
dns_rdata_covers(dns_rdata_t *rdata) {
        if (rdata->type == 46)
                return (covers_rrsig(rdata));
        return (covers_sig(rdata));
}

isc_boolean_t
dns_rdatatype_ismeta(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_META) != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdatatype_issingleton(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_SINGLETON)
            != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdatatype_notquestion(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_NOTQUESTION)
            != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdatatype_questiononly(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_QUESTIONONLY)
            != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdatatype_atparent(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_ATPARENT) != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdataclass_ismeta(dns_rdataclass_t rdclass) {

        if (rdclass == dns_rdataclass_reserved0
            || rdclass == dns_rdataclass_none
            || rdclass == dns_rdataclass_any)
                return (ISC_TRUE);

        return (ISC_FALSE);  /* Assume it is not a meta class. */
}

isc_boolean_t
dns_rdatatype_isdnssec(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_DNSSEC) != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdatatype_iszonecutauth(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type)
             & (DNS_RDATATYPEATTR_DNSSEC | DNS_RDATATYPEATTR_ZONECUTAUTH))
            != 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

isc_boolean_t
dns_rdatatype_isknown(dns_rdatatype_t type) {
        if ((dns_rdatatype_attributes(type) & DNS_RDATATYPEATTR_UNKNOWN)
            == 0)
                return (ISC_TRUE);
        return (ISC_FALSE);
}

void
dns_rdata_exists(dns_rdata_t *rdata, dns_rdatatype_t type) {

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

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

void
dns_rdata_notexist(dns_rdata_t *rdata, dns_rdatatype_t type) {

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

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

void
dns_rdata_deleterrset(dns_rdata_t *rdata, dns_rdatatype_t type) {

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

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

void
dns_rdata_makedelete(dns_rdata_t *rdata) {
        REQUIRE(rdata != NULL);

        rdata->rdclass = dns_rdataclass_none;
}

const char *
dns_rdata_updateop(dns_rdata_t *rdata, dns_section_t section) {

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

        switch (section) {
        case DNS_SECTION_PREREQUISITE:
                switch (rdata->rdclass) {
                case dns_rdataclass_none:
                        switch (rdata->type) {
                        case dns_rdatatype_any:
                                return ("domain doesn't exist");
                        default:
                                return ("rrset doesn't exist");
                        }
                case dns_rdataclass_any:
                        switch (rdata->type) {
                        case dns_rdatatype_any:
                                return ("domain exists");
                        default:
                                return ("rrset exists (value independent)");
                        }
                default:
                        return ("rrset exists (value dependent)");
                }
        case DNS_SECTION_UPDATE:
                switch (rdata->rdclass) {
                case dns_rdataclass_none:
                        return ("delete");
                case dns_rdataclass_any:
                        switch (rdata->type) {
                        case dns_rdatatype_any:
                                return ("delete all rrsets");
                        default:
                                return ("delete rrset");
                        }
                default:
                        return ("add");
                }
        }
        return ("invalid");
}

---