通过JS获取真实的外网IP和内网IP

//get the IP addresses associated with an account
function getIPs(callback) {
  var ip_dups = {};

  //compatibility for firefox and chrome
  var RTCPeerConnection =
    window.RTCPeerConnection ||
    window.mozRTCPeerConnection ||
    window.webkitRTCPeerConnection;

  //bypass naive webrtc blocking
  if (!RTCPeerConnection) {
    var iframe = document.createElement('iframe');
    //invalidate content script
    iframe.sandbox = 'allow-same-origin';
    iframe.style.display = 'none';
    document.body.appendChild(iframe);
    var win = iframe.contentWindow;
    window.RTCPeerConnection = win.RTCPeerConnection;
    window.mozRTCPeerConnection = win.mozRTCPeerConnection;
    window.webkitRTCPeerConnection = win.webkitRTCPeerConnection;
    RTCPeerConnection =
      window.RTCPeerConnection ||
      window.mozRTCPeerConnection ||
      window.webkitRTCPeerConnection;
  }

  //minimal requirements for data connection
  var mediaConstraints = {
    optional: [{ RtpDataChannels: true }],
  };

  //firefox already has a default stun server in about:config
  //    media.peerconnection.default_iceservers =
  //    [{"url": "stun:stun.services.mozilla.com"}]
  var servers = undefined;

  //add same stun server for chrome
  if (window.webkitRTCPeerConnection)
    servers = { iceServers: [{ urls: 'stun:stun.services.mozilla.com' }] };

  //construct a new RTCPeerConnection
  var pc = new RTCPeerConnection(servers, mediaConstraints);

  //listen for candidate events
  pc.onicecandidate = function (ice) {
    //skip non-candidate events
    if (ice.candidate) {
      //match just the IP address
      var ip_regex = /([0-9]{1,3}(\.[0-9]{1,3}){3})/;
      var ip_addr = ip_regex.exec(ice.candidate.candidate)[1];

      //remove duplicates
      if (ip_dups[ip_addr] === undefined) callback(ip_addr);

      ip_dups[ip_addr] = true;
    }
  };

  //create a bogus data channel
  pc.createDataChannel('');

  //create an offer sdp
  pc.createOffer(
    function (result) {
      //trigger the stun server request
      pc.setLocalDescription(
        result,
        function () {},
        function () {}
      );
    },
    function () {}
  );
}

//Test: Print the IP addresses into the console
getIPs(function (ip) {
  console.log(ip);
});