opt_41.c

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/*
 * Copyright (C) 2004, 2005, 2007, 2009, 2011-2014  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2002  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id$ */

/* Reviewed: Thu Mar 16 14:06:44 PST 2000 by gson */

/* RFC2671 */

#ifndef RDATA_GENERIC_OPT_41_C
#define RDATA_GENERIC_OPT_41_C

#define RRTYPE_OPT_ATTRIBUTES (DNS_RDATATYPEATTR_SINGLETON | \
                               DNS_RDATATYPEATTR_META | \
                               DNS_RDATATYPEATTR_NOTQUESTION)

static inline isc_result_t
fromtext_opt(ARGS_FROMTEXT) {
        /*
         * OPT records do not have a text format.
         */

        REQUIRE(type == 41);

        UNUSED(type);
        UNUSED(rdclass);
        UNUSED(lexer);
        UNUSED(origin);
        UNUSED(options);
        UNUSED(target);
        UNUSED(callbacks);

        return (ISC_R_NOTIMPLEMENTED);
}

static inline isc_result_t
totext_opt(ARGS_TOTEXT) {
        isc_region_t r;
        isc_region_t or;
        isc_uint16_t option;
        isc_uint16_t length;
        char buf[sizeof("64000 64000")];

        /*
         * OPT records do not have a text format.
         */

        REQUIRE(rdata->type == 41);

        dns_rdata_toregion(rdata, &r);
        while (r.length > 0) {
                option = uint16_fromregion(&r);
                isc_region_consume(&r, 2);
                length = uint16_fromregion(&r);
                isc_region_consume(&r, 2);
                sprintf(buf, "%u %u", option, length);
                RETERR(str_totext(buf, target));
                INSIST(r.length >= length);
                if (length > 0) {
                        if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
                                RETERR(str_totext(" (", target));
                        RETERR(str_totext(tctx->linebreak, target));
                        or = r;
                        or.length = length;
                        if (tctx->width == 0)   /* No splitting */
                                RETERR(isc_base64_totext(&or, 60, "", target));
                        else
                                RETERR(isc_base64_totext(&or, tctx->width - 2,
                                                         tctx->linebreak,
                                                         target));
                        isc_region_consume(&r, length);
                        if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
                                RETERR(str_totext(" )", target));
                }
                if (r.length > 0)
                        RETERR(str_totext(" ", target));
        }

        return (ISC_R_SUCCESS);
}

static inline isc_result_t
fromwire_opt(ARGS_FROMWIRE) {
        isc_region_t sregion;
        isc_region_t tregion;
        isc_uint16_t opt;
        isc_uint16_t length;
        unsigned int total;

        REQUIRE(type == 41);

        UNUSED(type);
        UNUSED(rdclass);
        UNUSED(dctx);
        UNUSED(options);

        isc_buffer_activeregion(source, &sregion);
        total = 0;
        while (sregion.length != 0) {
                if (sregion.length < 4)
                        return (ISC_R_UNEXPECTEDEND);
                opt = uint16_fromregion(&sregion);
                isc_region_consume(&sregion, 2);
                length = uint16_fromregion(&sregion);
                isc_region_consume(&sregion, 2);
                total += 4;
                if (sregion.length < length)
                        return (ISC_R_UNEXPECTEDEND);
                switch (opt) {
                case DNS_OPT_CLIENT_SUBNET: {
                        isc_uint16_t family;
                        isc_uint8_t addrlen;
                        isc_uint8_t scope;
                        isc_uint8_t addrbytes;

                        if (length < 4)
                                return (DNS_R_FORMERR);
                        family = uint16_fromregion(&sregion);
                        isc_region_consume(&sregion, 2);
                        addrlen = uint8_fromregion(&sregion);
                        isc_region_consume(&sregion, 1);
                        scope = uint8_fromregion(&sregion);
                        isc_region_consume(&sregion, 1);
                        switch (family) {
                        case 1:
                                if (addrlen > 32U || scope > 32U)
                                        return (DNS_R_FORMERR);
                                break;
                        case 2:
                                if (addrlen > 128U || scope > 128U)
                                        return (DNS_R_FORMERR);
                                break;
                        }
                        addrbytes = (addrlen + 7) / 8;
                        if (addrbytes + 4 != length)
                                return (DNS_R_FORMERR);
                        isc_region_consume(&sregion, addrbytes);
                        break;
                }
                case DNS_OPT_EXPIRE:
                        /*
                         * Request has zero length.  Response is 32 bits.
                         */
                        if (length != 0 && length != 4)
                                return (DNS_R_FORMERR);
                        isc_region_consume(&sregion, length);
                        break;
                default:
                        isc_region_consume(&sregion, length);
                        break;
                }
                total += length;
        }

        isc_buffer_activeregion(source, &sregion);
        isc_buffer_availableregion(target, &tregion);
        if (tregion.length < total)
                return (ISC_R_NOSPACE);
        memmove(tregion.base, sregion.base, total);
        isc_buffer_forward(source, total);
        isc_buffer_add(target, total);

        return (ISC_R_SUCCESS);
}

static inline isc_result_t
towire_opt(ARGS_TOWIRE) {

        REQUIRE(rdata->type == 41);

        UNUSED(cctx);

        return (mem_tobuffer(target, rdata->data, rdata->length));
}

static inline int
compare_opt(ARGS_COMPARE) {
        isc_region_t r1;
        isc_region_t r2;

        REQUIRE(rdata1->type == rdata2->type);
        REQUIRE(rdata1->rdclass == rdata2->rdclass);
        REQUIRE(rdata1->type == 41);

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

static inline isc_result_t
fromstruct_opt(ARGS_FROMSTRUCT) {
        dns_rdata_opt_t *opt = source;
        isc_region_t region;
        isc_uint16_t length;

        REQUIRE(type == 41);
        REQUIRE(source != NULL);
        REQUIRE(opt->common.rdtype == type);
        REQUIRE(opt->common.rdclass == rdclass);
        REQUIRE(opt->options != NULL || opt->length == 0);

        UNUSED(type);
        UNUSED(rdclass);

        region.base = opt->options;
        region.length = opt->length;
        while (region.length >= 4) {
                isc_region_consume(&region, 2); /* opt */
                length = uint16_fromregion(&region);
                isc_region_consume(&region, 2);
                if (region.length < length)
                        return (ISC_R_UNEXPECTEDEND);
                isc_region_consume(&region, length);
        }
        if (region.length != 0)
                return (ISC_R_UNEXPECTEDEND);

        return (mem_tobuffer(target, opt->options, opt->length));
}

static inline isc_result_t
tostruct_opt(ARGS_TOSTRUCT) {
        dns_rdata_opt_t *opt = target;
        isc_region_t r;

        REQUIRE(rdata->type == 41);
        REQUIRE(target != NULL);

        opt->common.rdclass = rdata->rdclass;
        opt->common.rdtype = rdata->type;
        ISC_LINK_INIT(&opt->common, link);

        dns_rdata_toregion(rdata, &r);
        opt->length = r.length;
        opt->options = mem_maybedup(mctx, r.base, r.length);
        if (opt->options == NULL)
                return (ISC_R_NOMEMORY);

        opt->offset = 0;
        opt->mctx = mctx;
        return (ISC_R_SUCCESS);
}

static inline void
freestruct_opt(ARGS_FREESTRUCT) {
        dns_rdata_opt_t *opt = source;

        REQUIRE(source != NULL);
        REQUIRE(opt->common.rdtype == 41);

        if (opt->mctx == NULL)
                return;

        if (opt->options != NULL)
                isc_mem_free(opt->mctx, opt->options);
        opt->mctx = NULL;
}

static inline isc_result_t
additionaldata_opt(ARGS_ADDLDATA) {
        REQUIRE(rdata->type == 41);

        UNUSED(rdata);
        UNUSED(add);
        UNUSED(arg);

        return (ISC_R_SUCCESS);
}

static inline isc_result_t
digest_opt(ARGS_DIGEST) {

        /*
         * OPT records are not digested.
         */

        REQUIRE(rdata->type == 41);

        UNUSED(rdata);
        UNUSED(digest);
        UNUSED(arg);

        return (ISC_R_NOTIMPLEMENTED);
}

static inline isc_boolean_t
checkowner_opt(ARGS_CHECKOWNER) {

        REQUIRE(type == 41);

        UNUSED(type);
        UNUSED(rdclass);
        UNUSED(wildcard);

        return (dns_name_equal(name, dns_rootname));
}

static inline isc_boolean_t
checknames_opt(ARGS_CHECKNAMES) {

        REQUIRE(rdata->type == 41);

        UNUSED(rdata);
        UNUSED(owner);
        UNUSED(bad);

        return (ISC_TRUE);
}

static inline int
casecompare_opt(ARGS_COMPARE) {
        return (compare_opt(rdata1, rdata2));
}

isc_result_t
dns_rdata_opt_first(dns_rdata_opt_t *opt) {

        REQUIRE(opt != NULL);
        REQUIRE(opt->common.rdtype == 41);
        REQUIRE(opt->options != NULL || opt->length == 0);

        if (opt->length == 0)
                return (ISC_R_NOMORE);

        opt->offset = 0;
        return (ISC_R_SUCCESS);
}

isc_result_t
dns_rdata_opt_next(dns_rdata_opt_t *opt) {
        isc_region_t r;
        isc_uint16_t length;

        REQUIRE(opt != NULL);
        REQUIRE(opt->common.rdtype == 41);
        REQUIRE(opt->options != NULL && opt->length != 0);
        REQUIRE(opt->offset < opt->length);

        INSIST(opt->offset + 4 <= opt->length);
        r.base = opt->options + opt->offset + 2;
        r.length = opt->length - opt->offset - 2;
        length = uint16_fromregion(&r);
        INSIST(opt->offset + 4 + length <= opt->length);
        opt->offset = opt->offset + 4 + length;
        if (opt->offset == opt->length)
                return (ISC_R_NOMORE);
        return (ISC_R_SUCCESS);
}

isc_result_t
dns_rdata_opt_current(dns_rdata_opt_t *opt, dns_rdata_opt_opcode_t *opcode) {
        isc_region_t r;

        REQUIRE(opt != NULL);
        REQUIRE(opcode != NULL);
        REQUIRE(opt->common.rdtype == 41);
        REQUIRE(opt->options != NULL);
        REQUIRE(opt->offset < opt->length);

        INSIST(opt->offset + 4 <= opt->length);
        r.base = opt->options + opt->offset;
        r.length = opt->length - opt->offset;

        opcode->opcode = uint16_fromregion(&r);
        isc_region_consume(&r, 2);
        opcode->length = uint16_fromregion(&r);
        isc_region_consume(&r, 2);
        opcode->data = r.base;
        INSIST(opt->offset + 4 + opcode->length <= opt->length);

        return (ISC_R_SUCCESS);
}

#endif  /* RDATA_GENERIC_OPT_41_C */

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