Skip to content

Instantly share code, notes, and snippets.

@dale3h
Last active Dec 14, 2015
Embed
What would you like to do?
Simple NodeJS UDP forwarding server
/**
* Simple NodeJS UDP forwarding server
*
* @author dale3h
*
* This script was built to run on a Raspberry Pi that is connected to two networks (wired + wireless).
* By default it listens on port 443, but only serves HTTP (not HTTPS)
*
* @usage
* http://192.168.1.102:443/send-udp?host=192.168.1.113&port=12345&device=wlan0&command=PACKET_CONTENTS
*
* This would be a Raspberry Pi running at 192.168.1.102 (on eth0), forwarding a UDP packet with the
* contents "PACKET_CONTENTS" to host 192.168.1.113, port 12345, using the wlan0 interface.
*
* @dependency httpdispatcher
*/
var http = require( 'http' );
var dispatcher = require( 'httpdispatcher' );
var util = require( 'util' );
var exec = require( 'child_process' ).exec;
const LISTEN_PORT = 443;
const SEND_TRIES = 3;
function handleRequest( request, response ) {
try {
//console.log( request.url );
dispatcher.dispatch( request, response );
} catch( err ) {
console.log( err );
}
}
function sendUDP( request, response ) {
var host = request.params.host || false;
var port = request.params.port || false;
var device = request.params.device || false;
var command = request.params.command || false;
var tries = request.params.tries || SEND_TRIES;
if ( ! host || ! port || ! command ) {
response.writeHead( 400, { 'Content-Type': 'text/plain' } );
response.end( '400 Bad Request' );
return;
}
sendUDPHelper( host, port, device, command, tries );
response.writeHead( 200, { 'Content-Type': 'text/plain' } );
response.end( command );
}
function sendUDPHelper( host, port, device, command, tries ) {
var child;
var bindto = '';
if ( device ) {
bindto = ',so-bindtodevice=' + device;
}
var cmd = 'echo \"' + command + '\" | sudo socat - UDP-DATAGRAM:' + host + ':' + port + bindto;
child = exec( cmd, function( error, stdout, stderr ) {
var header = '[' + getDateTime() + '] [' + (device ? device + ':' : '' ) + host + ':' + port + '] ';
if ( error !== null ) {
console.log( header + 'ERROR: ' + error );
return;
}
console.log( header + command );
} );
if ( --tries > 0 ) {
sendUDPHelper( host, port, device, command, tries );
}
}
function getDateTime() {
var date = new Date();
var hour = date.getHours();
hour = ( hour < 10 ? "0" : "" ) + hour;
var min = date.getMinutes();
min = ( min < 10 ? "0" : "" ) + min;
var sec = date.getSeconds();
sec = ( sec < 10 ? "0" : "" ) + sec;
var year = date.getFullYear();
var month = date.getMonth() + 1;
month = ( month < 10 ? "0" : "" ) + month;
var day = date.getDate();
day = ( day < 10 ? "0" : "" ) + day;
return year + "-" + month + "-" + day + " " + hour + ":" + min + ":" + sec;
}
dispatcher.onGet( '/send-udp', sendUDP );
dispatcher.onPost( '/send-udp', sendUDP );
var server = http.createServer( handleRequest );
server.listen( LISTEN_PORT, function() {
console.log( '[' + getDateTime() + '] Server listening on: http://localhost:%s', LISTEN_PORT );
} );
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment