opcodes.js

'use strict'

/*
 * Traditional DNS header OPCODEs (4-bits) defined by IANA in
 * https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-5
 */

exports.toString = function (opcode) {
  switch (opcode) {
    case 0: return 'QUERY'
    case 1: return 'IQUERY'
    case 2: return 'STATUS'
    case 3: return 'OPCODE_3'
    case 4: return 'NOTIFY'
    case 5: return 'UPDATE'
    case 6: return 'OPCODE_6'
    case 7: return 'OPCODE_7'
    case 8: return 'OPCODE_8'
    case 9: return 'OPCODE_9'
    case 10: return 'OPCODE_10'
    case 11: return 'OPCODE_11'
    case 12: return 'OPCODE_12'
    case 13: return 'OPCODE_13'
    case 14: return 'OPCODE_14'
    case 15: return 'OPCODE_15'
  }
  return 'OPCODE_' + opcode
}

exports.toOpcode = function (code) {
  switch (code.toUpperCase()) {
    case 'QUERY': return 0
    case 'IQUERY': return 1
    case 'STATUS': return 2
    case 'OPCODE_3': return 3
    case 'NOTIFY': return 4
    case 'UPDATE': return 5
    case 'OPCODE_6': return 6
    case 'OPCODE_7': return 7
    case 'OPCODE_8': return 8
    case 'OPCODE_9': return 9
    case 'OPCODE_10': return 10
    case 'OPCODE_11': return 11
    case 'OPCODE_12': return 12
    case 'OPCODE_13': return 13
    case 'OPCODE_14': return 14
    case 'OPCODE_15': return 15
  }
  return 0
}