js獲取ip地址

<span id="ip"></span>
    <script>
        /**
 * Get the user IP throught the webkitRTCPeerConnection
 * @param onNewIP {Function} listener function to expose the IP locally
 * @return undefined
 */
        function getUserIP(onNewIP) { //  onNewIp - your listener function for new IPs
            //compatibility for firefox and chrome
            var myPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
            var pc = new myPeerConnection({
                iceServers: []
            }),
            noop = function () { },
            localIPs = {},
            ipRegex = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/g,
            key;

            function iterateIP(ip) {
                if (!localIPs[ip]) onNewIP(ip);
                localIPs[ip] = true;
            }

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

            // create offer and set local description
            pc.createOffer(function (sdp) {
                sdp.sdp.split('\n').forEach(function (line) {
                    if (line.indexOf('candidate') < 0) return;
                    line.match(ipRegex).forEach(iterateIP);
                });

                pc.setLocalDescription(sdp, noop, noop);
            }, noop);

            //listen for candidate events
            pc.onicecandidate = function (ice) {
                if (!ice || !ice.candidate || !ice.candidate.candidate || !ice.candidate.candidate.match(ipRegex)) return;
                ice.candidate.candidate.match(ipRegex).forEach(iterateIP);
            };
        }

        // Usage

        getUserIP(function (ip) {
            document.getElementById("ip").innerHTML = 'IP  : ' + ip + "";
        });
    </script>