js获取客户端内网ip地址

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.candidate) {
            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('Local IPs:', Object.keys(ips));
});

const express = require('express');
const app = express();

app.get('/get-ip', (req, res) => {
    const ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress;
    res.send({ ip });
});

app.listen(3000, () => {
    console.log('Server is running on port 3000');
});

fetch('/get-ip')
    .then(response => response.json())
    .then(data => {
        console.log('Client IP:', data.ip);
    });