/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/* 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)

#include <isc/utf8.h>

static inline isc_result_t

fromtext_opt(ARGS_FROMTEXT) {

  /*

   * OPT records do not have a text format.

   */

  REQUIRE(type == dns_rdatatype_opt);

  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 ;

  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(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;

  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_LLQ:

      if (length != 18U) {

        return (DNS_R_OPTERR);

      }

      isc_region_consume(&sregion, length);

      break;

    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:

      /*

       * Client cookie alone has length 8.

       * Client + server cookie is 8 + [8..32].

       */

      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;

    case DNS_OPT_EDE:

      if (length < 2) {

        return (DNS_R_OPTERR);

      }

      /* UTF-8 Byte Order Mark is not permitted. RFC 5198 */

      if (isc_utf8_bom(sregion.base + 2, length - 2)) {

        return (DNS_R_OPTERR);

      }

      /*

       * The EXTRA-TEXT field is specified as UTF-8, and

       * therefore must be validated for correctness

       * according to RFC 3269 security considerations.

       */

      if (!isc_utf8_valid(sregion.base + 2, length - 2)) {

        return (DNS_R_OPTERR);

      }

      isc_region_consume(&sregion, length);

      break;

    case DNS_OPT_CLIENT_TAG:

    /* FALLTHROUGH */

    case DNS_OPT_SERVER_TAG:

      if (length != 2) {

        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 (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 == dns_rdatatype_opt);

  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;

  uint16_t length;

  REQUIRE(type == dns_rdatatype_opt);

  REQUIRE(opt != 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 == dns_rdatatype_opt);

  REQUIRE(opt != 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);

  opt->offset = 0;

  opt->mctx = mctx;

  return (ISC_R_SUCCESS);

}

static inline void

freestruct_opt(ARGS_FREESTRUCT) {

  dns_rdata_opt_t *opt = source;

  REQUIRE(opt != NULL);

  REQUIRE(opt->common.rdtype == dns_rdatatype_opt);

  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 == dns_rdatatype_opt);

  UNUSED(rdata);

  UNUSED(owner);

  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 == dns_rdatatype_opt);

  UNUSED(rdata);

  UNUSED(digest);

  UNUSED(arg);

  return (ISC_R_NOTIMPLEMENTED);

}

static inline bool

checkowner_opt(ARGS_CHECKOWNER) {

  REQUIRE(type == dns_rdatatype_opt);

  UNUSED(type);

  UNUSED(rdclass);

  UNUSED(wildcard);

  return (dns_name_equal(name, dns_rootname));

}

static inline bool

checknames_opt(ARGS_CHECKNAMES) {

  REQUIRE(rdata->type == dns_rdatatype_opt);

  UNUSED(rdata);

  UNUSED(owner);

  UNUSED(bad);

  return (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 == dns_rdatatype_opt);

  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;

  uint16_t length;

  REQUIRE(opt != NULL);

  REQUIRE(opt->common.rdtype == dns_rdatatype_opt);

  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 == dns_rdatatype_opt);

  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 */