shadowsocks/lib/shadowsocks/inet.js

a tunnel proxy that help you get through firewalls

// The functions in source file is from phpjs
// https://github.com/kvz/phpjs
// See license below
//
// Copyright (c) 2013 Kevin van Zonneveld (http://kvz.io) 
// and Contributors (http://phpjs.org/authors)
// 
// 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.


function inet_pton (a) {
  // http://kevin.vanzonneveld.net
  // +   original by: Theriault
  // *     example 1: inet_pton('::');
  // *     returns 1: '\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0' (binary)
  // *     example 2: inet_pton('127.0.0.1');
  // *     returns 2: '\x7F\x00\x00\x01' (binary)
  var r, m, x, i, j, f = String.fromCharCode;
  m = a.match(/^(?:\d{1,3}(?:\.|$)){4}/); // IPv4
  if (m) {
    m = m[0].split('.');
    m = f(m[0]) + f(m[1]) + f(m[2]) + f(m[3]);
    // Return if 4 bytes, otherwise false.
    return m.length === 4 ? m : false;
  }
  r = /^((?:[\da-f]{1,4}(?::|)){0,8})(::)?((?:[\da-f]{1,4}(?::|)){0,8})$/;
  m = a.match(r); // IPv6
  if (m) {
    // Translate each hexadecimal value.
    for (j = 1; j < 4; j++) {
      // Indice 2 is :: and if no length, continue.
      if (j === 2 || m[j].length === 0) {
        continue;
      }
      m[j] = m[j].split(':');
      for (i = 0; i < m[j].length; i++) {
        m[j][i] = parseInt(m[j][i], 16);
        // Would be NaN if it was blank, return false.
        if (isNaN(m[j][i])) {
          return false; // Invalid IP.
        }
        m[j][i] = f(m[j][i] >> 8) + f(m[j][i] & 0xFF);
      }
      m[j] = m[j].join('');
    }
    x = m[1].length + m[3].length;
    if (x === 16) {
      return m[1] + m[3];
    } else if (x < 16 && m[2].length > 0) {
      return m[1] + (new Array(16 - x + 1)).join('\x00') + m[3];
    }
  }
  return false; // Invalid IP.
}

function inet_ntop (a) {
  // http://kevin.vanzonneveld.net
  // +   original by: Theriault
  // *     example 1: inet_ntop('\x7F\x00\x00\x01');
  // *     returns 1: '127.0.0.1'
  // *     example 2: inet_ntop('\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1');
  // *     returns 2: '::1'
  var i = 0,
    m = '',
    c = [];
  if (a.length === 4) { // IPv4
    a += '';
    return [
    a.charCodeAt(0), a.charCodeAt(1), a.charCodeAt(2), a.charCodeAt(3)].join('.');
  } else if (a.length === 16) { // IPv6
    for (i = 0; i < 16; i += 2) {
      var group = (a.slice(i, i + 2)).toString("hex");
      //replace 00b1 => b1  0000=>0
      while(group.length > 1 && group.slice(0,1) == '0')
        group = group.slice(1);
      c.push(group);
    }
    return c.join(':').replace(/((^|:)0(?=:|$))+:?/g, function (t) {
      m = (t.length > m.length) ? t : m;
      return t;
    }).replace(m || ' ', '::');
  } else { // Invalid length
    return false;
  }
}
exports.inet_pton = inet_pton;
exports.inet_ntop = inet_ntop;