js 不连接外网获取内网ip

function getLocalIPs(callback) {
    const RTCPeerConnection = window.RTCPeerConnection || window.webkitRTCPeerConnection || window.mozRTCPeerConnection;
    const ips = {};

    if (!RTCPeerConnection) {
        callback(ips);
        return;
    }

    const rtc = new RTCPeerConnection({ iceServers: [] });
    rtc.createDataChannel('', { reliable: false });

    rtc.onicecandidate = function (ice) {
        if (!ice || !ice.candidate || !ice.candidate.candidate) return;
        const ipMatch = /([0-9]{1,3}(\.[0-9]{1,3}){3})/.exec(ice.candidate.candidate);
        if (ipMatch) {
            const ip = ipMatch[1];
            ips[ip] = true;
            callback(ips);
        }
    };

    rtc.createOffer().then(offer => rtc.setLocalDescription(offer));
}

getLocalIPs(function (ips) {
    console.log('内网 IP 地址:', Object.keys(ips));
});