udx-native/lib/ip.js

udx is reliable, multiplexed, and congestion-controlled streams over udp

// Copyright Joyent, Inc. and other Node contributors.
//
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// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
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// 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.
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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const v4Seg = '(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])'
const v4Str = `(${v4Seg}[.]){3}${v4Seg}`
const IPv4Pattern = new RegExp(`^${v4Str}$`)

const v6Seg = '(?:[0-9a-fA-F]{1,4})'
const IPv6Pattern = new RegExp('^(' +
  `(?:${v6Seg}:){7}(?:${v6Seg}|:)|` +
  `(?:${v6Seg}:){6}(?:${v4Str}|:${v6Seg}|:)|` +
  `(?:${v6Seg}:){5}(?::${v4Str}|(:${v6Seg}){1,2}|:)|` +
  `(?:${v6Seg}:){4}(?:(:${v6Seg}){0,1}:${v4Str}|(:${v6Seg}){1,3}|:)|` +
  `(?:${v6Seg}:){3}(?:(:${v6Seg}){0,2}:${v4Str}|(:${v6Seg}){1,4}|:)|` +
  `(?:${v6Seg}:){2}(?:(:${v6Seg}){0,3}:${v4Str}|(:${v6Seg}){1,5}|:)|` +
  `(?:${v6Seg}:){1}(?:(:${v6Seg}){0,4}:${v4Str}|(:${v6Seg}){1,6}|:)|` +
  `(?::((?::${v6Seg}){0,5}:${v4Str}|(?::${v6Seg}){1,7}|:))` +
')(%[0-9a-zA-Z-.:]{1,})?$')

const isIPv4 = exports.isIPv4 = function isIPv4 (host) {
  return IPv4Pattern.test(host)
}

const isIPv6 = exports.isIPv6 = function isIPv6 (host) {
  return IPv6Pattern.test(host)
}

exports.isIP = function isIP (host) {
  if (isIPv4(host)) return 4
  if (isIPv6(host)) return 6
  return 0
}