rdata/in_1/a6_38.c

	a6_38.c revision 8360c3dc0f8ab25f4839c79e30d6865838d9a4da
/*
 * Copyright (C) 1999 Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM 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: a6_38.c,v 1.11 1999/07/16 00:24:32 halley Exp $ */

 /* draft-ietf-ipngwg-dns-lookups-03.txt */

#ifndef RDATA_IN_1_A6_28_C
#define RDATA_IN_1_A6_28_C

#include <string.h>

#include <isc/net.h>

#ifndef MAX
#define MAX(A, B) ((A > B) ? (A) : (B))
#endif

static dns_result_t
fromtext_in_a6(dns_rdataclass_t class, dns_rdatatype_t type,
           isc_lex_t *lexer, dns_name_t *origin,
           isc_boolean_t downcase, isc_buffer_t *target)
{
    isc_token_t token;
    unsigned char addr[16];
    unsigned char prefixlen;
    unsigned char octets;
    unsigned char mask;
    dns_name_t name;
    isc_buffer_t buffer;

    REQUIRE(type == 38);
    REQUIRE(class == 1);

    /* prefix length */
    RETERR(gettoken(lexer, &token, isc_tokentype_number, ISC_FALSE));
    if (token.value.as_ulong > 128)
        return (DNS_R_RANGE);

    prefixlen = token.value.as_ulong;
    RETERR(mem_tobuffer(target, &prefixlen, 1));

    /* suffix */
    if (prefixlen != 128) {
        /* prefix 0..127 */
        octets = prefixlen/8;
        /* octets 0..15 */
        RETERR(gettoken(lexer, &token, isc_tokentype_string,
                ISC_FALSE));
        if (inet_pton(AF_INET6, token.value.as_pointer, addr) != 1)
            return (DNS_R_BADAAAA);
        mask = 0xff >> (prefixlen % 8);
        addr[octets] &= mask;
        RETERR(mem_tobuffer(target, &addr[octets], 16 - octets));
    }

    if (prefixlen == 0)
        return (DNS_R_SUCCESS);

    RETERR(gettoken(lexer, &token, isc_tokentype_string, ISC_FALSE));
    dns_name_init(&name, NULL);
    buffer_fromregion(&buffer, &token.value.as_region,
              ISC_BUFFERTYPE_TEXT);
    origin = (origin != NULL) ? origin : dns_rootname;
    return (dns_name_fromtext(&name, &buffer, origin, downcase, target));
}

static dns_result_t
totext_in_a6(dns_rdata_t *rdata, dns_rdata_textctx_t *tctx,
         isc_buffer_t *target)
{
    isc_region_t tr;
    isc_region_t sr;
    unsigned char addr[16];
    unsigned char prefixlen;
    unsigned char octets;
    unsigned char mask;
    char buf[sizeof "128"];
    dns_name_t name;
    dns_name_t prefix;
    isc_boolean_t sub;

    REQUIRE(rdata->type == 38);
    REQUIRE(rdata->class == 1);

    dns_rdata_toregion(rdata, &sr);
    prefixlen = sr.base[0];
    INSIST(prefixlen <= 128);
    isc_region_consume(&sr, 1);
    sprintf(buf, "%u", prefixlen);
    RETERR(str_totext(buf, target));
    RETERR(str_totext(" ", target));

    if (prefixlen != 128) {
        octets = prefixlen/8;
        memset(addr, 0, sizeof addr);
        memcpy(&addr[octets], sr.base, 16 - octets);
        mask = 0xff >> (prefixlen % 8);
        addr[octets] &= mask;
        isc_buffer_available(target, &tr);
        if (inet_ntop(AF_INET6, addr,
                  (char *)tr.base, tr.length) == NULL)
            return (DNS_R_NOSPACE);

        isc_buffer_add(target, strlen((char *)tr.base));
        isc_region_consume(&sr, 16 - octets);
    }

    if (prefixlen == 0)
        return (DNS_R_SUCCESS);

    RETERR(str_totext(" ", target));
    dns_name_init(&name, NULL);
    dns_name_init(&prefix, NULL);
    dns_name_fromregion(&name, &sr);
    sub = name_prefix(&name, tctx->origin, &prefix);
    return(dns_name_totext(&prefix, sub, target));
}

static dns_result_t
fromwire_in_a6(dns_rdataclass_t class, dns_rdatatype_t type,
          isc_buffer_t *source, dns_decompress_t *dctx,
          isc_boolean_t downcase, isc_buffer_t *target)
{
    isc_region_t sr;
    unsigned char prefixlen;
    unsigned char octets;
    unsigned char mask;
    dns_name_t name;

    REQUIRE(type == 38);
    REQUIRE(class == 1);

    if (dns_decompress_edns(dctx) >= 1 || !dns_decompress_strict(dctx))
        dns_decompress_setmethods(dctx, DNS_COMPRESS_ALL);
    else
        dns_decompress_setmethods(dctx, DNS_COMPRESS_NONE);

    isc_buffer_active(source, &sr);
    /* prefix length */
    if (sr.length < 1)
        return (DNS_R_UNEXPECTEDEND);
    prefixlen = sr.base[0];
    if (prefixlen > 128)
        return (DNS_R_RANGE);
    isc_region_consume(&sr, 1);
    RETERR(mem_tobuffer(target, &prefixlen, 1));
    isc_buffer_forward(source, 1);

    /* suffix */
    if (prefixlen != 128) {
        octets = 16 - prefixlen / 8;
        if (sr.length < octets)
            return (DNS_R_UNEXPECTEDEND);
        mask = 0xff >> (prefixlen % 8);
        sr.base[0] &= mask; /* ensure pad bits are zero */
        RETERR(mem_tobuffer(target, sr.base, octets));
        isc_buffer_forward(source, octets);
    }

    if (prefixlen == 0)
        return (DNS_R_SUCCESS);

    dns_name_init(&name, NULL);
    return (dns_name_fromwire(&name, source, dctx, downcase, target));
}

static dns_result_t
towire_in_a6(dns_rdata_t *rdata, dns_compress_t *cctx, isc_buffer_t *target) {
    isc_region_t sr;
    dns_name_t name;
    unsigned char prefixlen;
    unsigned char octets;

    REQUIRE(rdata->type == 38);
    REQUIRE(rdata->class == 1);

    if (dns_compress_getedns(cctx) >= 1)
        dns_compress_setmethods(cctx, DNS_COMPRESS_ALL);
    else
        dns_compress_setmethods(cctx, DNS_COMPRESS_NONE);

    dns_rdata_toregion(rdata, &sr);
    prefixlen = sr.base[0];
    INSIST(prefixlen <= 128);

    octets = 1 + 16 - prefixlen / 8;
    RETERR(mem_tobuffer(target, sr.base, octets));
    isc_region_consume(&sr, octets);

    if (prefixlen == 0)
        return (DNS_R_SUCCESS);

    dns_name_init(&name, NULL);
    dns_name_fromregion(&name, &sr);
    return (dns_name_towire(&name, cctx, target));
}

static int
compare_in_a6(dns_rdata_t *rdata1, dns_rdata_t *rdata2) {
    int result;
    unsigned char prefixlen;
    unsigned char octets;
    dns_name_t name1;
    dns_name_t name2;
    isc_region_t region1;
    isc_region_t region2;

    REQUIRE(rdata1->type == rdata2->type);
    REQUIRE(rdata1->class == rdata2->class);
    REQUIRE(rdata1->type == 38);
    REQUIRE(rdata1->class == 1);

    dns_rdata_toregion(rdata1, &region1);
    dns_rdata_toregion(rdata2, &region2);
    prefixlen = MAX(region1.base[0], region2.base[0]);
    octets = 1 + 16 - prefixlen / 8;

    result = memcmp(region1.base, region2.base, octets);
    if (result != 0)
        result = (result < 0) ? -1 : 1;

    isc_region_consume(&region1, octets);
    isc_region_consume(&region2, octets);

    dns_name_init(&name1, NULL);
    dns_name_init(&name2, NULL);
    dns_name_fromregion(&name1, &region1);
    dns_name_fromregion(&name2, &region2);
    return (dns_name_rdatacompare(&name1, &name2));
}

static dns_result_t
fromstruct_in_a6(dns_rdataclass_t class, dns_rdatatype_t type, void *source,
         isc_buffer_t *target)
{

    REQUIRE(type == 1);
    REQUIRE(class == 1);

    source = source;
    target = target;

    return (DNS_R_NOTIMPLEMENTED);
}

static dns_result_t
tostruct_in_a6(dns_rdata_t *rdata, void *target, isc_mem_t *mctx) {

    REQUIRE(rdata->type == 38);
    REQUIRE(rdata->class == 1);

    target = target;
    mctx = mctx;

    return (DNS_R_NOTIMPLEMENTED);
}

static void
freestruct_in_a6(void *source) {
    REQUIRE(source != NULL);
    REQUIRE(ISC_FALSE); /*XXX*/
}
#endif  /* RDATA_IN_1_A6_38_C */