optioncodes.js

/*
 * Copyright (c) 2021 RethinkDNS and its authors.
 *
 * 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 http://mozilla.org/MPL/2.0/.
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Mathias Buus
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

//forked with minor changes from https://github.com/mafintosh/dns-packet

"use strict";

export function toString(type) {
  switch (type) {
    // list at
    // https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-11
    case 1:
      return "LLQ";
    case 2:
      return "UL";
    case 3:
      return "NSID";
    case 5:
      return "DAU";
    case 6:
      return "DHU";
    case 7:
      return "N3U";
    case 8:
      return "CLIENT_SUBNET";
    case 9:
      return "EXPIRE";
    case 10:
      return "COOKIE";
    case 11:
      return "TCP_KEEPALIVE";
    case 12:
      return "PADDING";
    case 13:
      return "CHAIN";
    case 14:
      return "KEY_TAG";
    case 26946:
      return "DEVICEID";
  }
  if (type < 0) {
    return null;
  }
  return `OPTION_${type}`;
}

export function toCode(name) {
  if (typeof name === "number") {
    return name;
  }
  if (!name) {
    return -1;
  }
  switch (name.toUpperCase()) {
    case "OPTION_0":
      return 0;
    case "LLQ":
      return 1;
    case "UL":
      return 2;
    case "NSID":
      return 3;
    case "OPTION_4":
      return 4;
    case "DAU":
      return 5;
    case "DHU":
      return 6;
    case "N3U":
      return 7;
    case "CLIENT_SUBNET":
      return 8;
    case "EXPIRE":
      return 9;
    case "COOKIE":
      return 10;
    case "TCP_KEEPALIVE":
      return 11;
    case "PADDING":
      return 12;
    case "CHAIN":
      return 13;
    case "KEY_TAG":
      return 14;
    case "DEVICEID":
      return 26946;
    case "OPTION_65535":
      return 65535;
  }
  const m = name.match(/_(\d+)$/);
  if (m) {
    return parseInt(m[1], 10);
  }
  return -1;
}