Question

141

Node.js - forward all traffic from port A to port B

rated 0 times [ 147] [ 6] / answers: 1 / hits: 29311 / 13 Years ago, mon, june 27, 2011, 12:00:00

I'm trying to forward all traffic from port 6999 to port 7000 (I know I could use iptables, but the idea is to use Node.js to do some packet inspection).

Here is the code I have sofar:

var net=require('net');

var compress=require('./node-compress/compress');



var ip='172.16.1.224';

var ipPort=6999;

var opPort=7000;



var output=net.createServer(function(connOut){

        var input=net.createServer(function(connIn){

                connIn.pipe(connOut);

        });

        input.listen(ipPort,ip);

});

output.listen(opPort,ip);

It just does not seem to work. When I do a tcpdump on port 7000, nothing shows up. Anyone have any suggestions?

Many thanks in advance,

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berenices

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answered 13 Years ago charity · Accepted Answer

Here's my go at it:

Supports giving the from and to from command line, and supports remote machines.

var net = require('net');



// parse 80 and localhost:80 or even 42mEANINg-life.com:80

var addrRegex = /^(([a-zA-Z-.0-9]+):)?(d+)$/;



var addr = {

    from: addrRegex.exec(process.argv[2]),

    to: addrRegex.exec(process.argv[3])

};



if (!addr.from || !addr.to) {

    console.log('Usage: <from> <to>');

    return;

}



net.createServer(function(from) {

    var to = net.createConnection({

        host: addr.to[2],

        port: addr.to[3]

    });

    from.pipe(to);

    to.pipe(from);

}).listen(addr.from[3], addr.from[2]);

(save as proxy.js)

To forward from localhost:9001 => localhost:80

$ node proxy.js 9001 80

Or localhost:9001 => otherhost:80

$ node proxy.js 9001 otherhost:80

(This was based on Andrey's answer, thanks!)