Mirror: Best-effort discovery of the machine's local network using just Node.js dgram sockets
kitten.sh
1import { createSocket } from 'dgram';
2
3const NOOP_PORT = 65535;
4const NOOP_IP = '255.255.255.255';
5const NO_ROUTE_IP = '0.0.0.0';
6
7class DefaultRouteError extends TypeError {
8 code = 'ECONNABORT';
9}
10
11export const probeDefaultRoute = (): Promise<string> => {
12 return new Promise((resolve, reject) => {
13 const socket = createSocket({ type: 'udp4', reuseAddr: true });
14 socket.on('error', error => {
15 reject(error);
16 socket.close();
17 socket.unref();
18 });
19 socket.connect(NOOP_PORT, NOOP_IP, () => {
20 const address = socket.address();
21 if (address && 'address' in address && address.address !== NO_ROUTE_IP) {
22 resolve(address.address);
23 } else {
24 reject(new DefaultRouteError('No route to host'));
25 }
26 socket.close();
27 socket.unref();
28 });
29 });
30};