Chrome Extension: Show IP Address

For Network Administrators, they sometimes need to know the IP addresses both internal and external. Therefore, I have developed a handy widget to the Chrome, so that you can easily get your own IP addresses with just one click.

The github source repro is: https://github.com/DoctorLai/what-is-my-ip
You can add to Chrome browser via Chrome web store: https://chrome.google.com/webstore/detail/show-my-ip-addresses-exte/opljiobgnagdjikipnagigiacllolpaj

A screenshot of the chrome extension to show the IP address:

What it does essentially is to invoke the show-ip-address API from 4 different API servers around the globe, although the internal IP address can be obtained via the following Javascript function:

function getLocalIPs(callback) {
    var ips = [];

    var RTCPeerConnection = window.RTCPeerConnection ||
        window.webkitRTCPeerConnection || window.mozRTCPeerConnection;

    var pc = new RTCPeerConnection({
        // Don't specify any stun/turn servers, otherwise you will
        // also find your public IP addresses.
        iceServers: []
    });
    // Add a media line, this is needed to activate candidate gathering.
    pc.createDataChannel('');
    
    // onicecandidate is triggered whenever a candidate has been found.
    pc.onicecandidate = function(e) {
        if (!e.candidate) { // Candidate gathering completed.
            pc.close();
            callback(ips);
            return;
        }
        var ip = /^candidate:.+ (\S+) \d+ typ/.exec(e.candidate.candidate)[1];
        if (ips.indexOf(ip) == -1) // avoid duplicate entries (tcp/udp)
            ips.push(ip);
    };
    pc.createOffer(function(sdp) {
        pc.setLocalDescription(sdp);
    }, function onerror() {});
}

Feel free to submit your Pull Requests at: https://github.com/DoctorLai/what-is-my-ip