/*
 * 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.
 */

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

/* RFC2671 */

#ifndef RDATA_GENERIC_OPT_41_C
#define RDATA_GENERIC_OPT_41_C

static inline isc_result_t
totext_opt(ARGS_TOTEXT) {
        isc_region_t r;
        isc_region_t or;
        uint16_t option;
        uint16_t length;
        char buf[sizeof("64000 64000")];

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

        REQUIRE(rdata->type == dns_rdatatype_opt);

        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);
                snprintf(buf, sizeof(buf), "%u %u", option, length);
                RETERR(isc_str_tobuffer(buf, target));
                INSIST(r.length >= length);
                if (length > 0) {
                        if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0)
                                RETERR(isc_str_tobuffer(" (", target));
                        RETERR(isc_str_tobuffer(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(isc_str_tobuffer(" )", target));
                }
                if (r.length > 0)
                        RETERR(isc_str_tobuffer(" ", target));
        }

        return (ISC_R_SUCCESS);
}

static inline isc_result_t
fromwire_opt(ARGS_FROMWIRE) {
        isc_region_t sregion;
        isc_region_t tregion;
        uint16_t opt;
        uint16_t length;
        unsigned int total;

        REQUIRE(type == dns_rdatatype_opt);

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

        isc_buffer_activeregion(source, &sregion);
        if (sregion.length == 0)
                return (ISC_R_SUCCESS);
        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: {
                        uint16_t family;
                        uint8_t addrlen;
                        uint8_t scope;
                        uint8_t addrbytes;

                        if (length < 4)
                                return (DNS_R_OPTERR);
                        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 0:
                                /*
                                 * XXXMUKS: In queries and replies, if
                                 * FAMILY is set to 0, SOURCE
                                 * PREFIX-LENGTH and SCOPE PREFIX-LENGTH
                                 * must be 0 and ADDRESS should not be
                                 * present as the address and prefix
                                 * lengths don't make sense because the
                                 * family is unknown.
                                 */
                                if (addrlen != 0U || scope != 0U)
                                        return (DNS_R_OPTERR);
                                break;
                        case 1:
                                if (addrlen > 32U || scope > 32U)
                                        return (DNS_R_OPTERR);
                                break;
                        case 2:
                                if (addrlen > 128U || scope > 128U)
                                        return (DNS_R_OPTERR);
                                break;
                        default:
                                return (DNS_R_OPTERR);
                        }
                        addrbytes = (addrlen + 7) / 8;
                        if (addrbytes + 4 != length)
                                return (DNS_R_OPTERR);

                        if (addrbytes != 0U && (addrlen % 8) != 0) {
                                uint8_t bits = ~0U << (8 - (addrlen % 8));
                                bits &= sregion.base[addrbytes - 1];
                                if (bits != sregion.base[addrbytes - 1])
                                        return (DNS_R_OPTERR);
                        }
                        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_OPTERR);
                        isc_region_consume(&sregion, length);
                        break;
                case DNS_OPT_COOKIE:
                        if (length != 8 && (length < 16 || length > 40))
                                return (DNS_R_OPTERR);
                        isc_region_consume(&sregion, length);
                        break;
                case DNS_OPT_KEY_TAG:
                        if (length == 0 || (length % 2) != 0)
                                return (DNS_R_OPTERR);
                        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 == dns_rdatatype_opt);

        UNUSED(cctx);

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

#endif  /* RDATA_GENERIC_OPT_41_C */