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#!/usr/bin/env node
// Note: this is unfinished and not currently used. Stashed in case we resurrect this idea.
var UDP_PORT_START = 9994;
var UDP_PORT_COUNT = 16384;
var HTTP_PORT = 8080;
var LONG_POLLING_TIMEOUT = 25000;
var http = require('http');
var dgram = require('dgram');
// clients[token] = [ most recent HTTP activity, assigned UDP socket ]
var clients = {};
// GETs[token] = [ [ request, timestamp ], ... ]
var GETs = {};
// mappings[localPort+'/'+remoteIp+'/'+remotePort] = { ZT source: [ token ] }
var mappings = {};
// Array of available UDP sockets to assign randomly to clients
var udpSocketPool = [];
function onIncomingUdp(socket,message,remoteIp,remotePort)
{
if (message.length > 16) {
var mappingKey = socket.localPort + '/' + remoteIp + '/' + remotePort;
var mapping = mappings[mappingKey];
if (mapping) {
var ztDestination = message.readUIntBE(8,5);
if (ztDestination in mapping) {
}
}
}
}
function onOutgoingUdp(token,socket,message,remoteIp,remotePort)
{
if (message.length > 16) {
var ztDestination = message.readUIntBE(8,5);
var ztSource = (message.length >= 28) ? message.readUIntBE(13,5) ? 0;
if ((ztSource & 0xff00000000) == 0xff00000000) // fragment
ztSource = 0;
if ((ztDestination !== 0)&&((ztDestination & 0xff00000000) !== 0xff00000000)) {
socket.send(message,0,message.length,remotePort,remoteIp);
}
}
}
function doHousekeeping()
{
}
for(var udpPort=UDP_PORT_START;udpPort<(UDP_PORT_START+UDP_PORT_COUNT)++udpPort) {
var socket = dgram.createSocket('udp4',function(message,rinfo) { onIncomingUdp(socket,message,rinfo.address,rinfo.port); });
socket.on('listening',function() {
console.log('Listening on '+socket.localPort);
udpSocketPool.push(socket);
}
socket.on('error',function() {
console.log('Error listening on '+socket.localPort);
socket.close();
})
socket.bind(udpPort);
}
server = http.createServer(function(request,response) {
console.log(request.socket.remoteAddress+" "+request.method+" "+request.url);
try {
// /<proxy token>/<ignored>/...
var urlSp = request.url.split('/');
if ((urlSp.length >= 3)&&(udpSocketPool.length > 0)) {
var token = urlSp[1]; // urlSp[0] == '' since URLs start with /
if (token.length >= 8) {
var client = clients[token];
if (!Array.isArray(client)) {
client = [ Date.now(),udpSocketPool[Math.floor(Math.random() * udpSocketPool.length)] ];
clients[token] = client;
} else client[0] = Date.now();
if (request.method === "GET") {
// /<proxy token>/<ignored> ... waits via old skool long polling
} else if (request.method === "POST") {
// /<proxy token>/<ignored>/<dest ip>/<dest port>
if (urlSp.length === 5) {
var ipSp = urlSp[3].split('.');
var port = parseInt(urlSp[4],10);
// Note: do not allow the use of this proxy to talk to privileged ports
if ((ipSp.length === 4)&&(port >= 1024)&&(port <= 0xffff)) {
var ip = [ parseInt(ipSp[0]),parseInt(ipSp[1]),parseInt(ipSp[2]),parseInt(ipSp[3]) ];
if ( (ip[0] > 0)
&&(ip[0] < 240)
&&(ip[0] !== 127)
&&(ip[1] >= 0)
&&(ip[1] <= 255)
&&(ip[2] >= 0)
&&(ip[2] <= 255)
&&(ip[3] > 0)
&&(ip[3] < 255) ) {
var postData = null;
request.on('data',function(chunk) {
postData = ((postData === null) ? chunk : Buffer.concat([ postData,chunk ]));
});
request.on('end',function() {
if (postData !== null)
onOutgoingUdp(token,client[1],postData,urlSp[3],port);
response.writeHead(200,{'Content-Length':0,'Pragma':'no-cache','Cache-Control':'no-cache'});
response.end();
});
return; // no 400 -- read from stream
} // else 400
} // else 400
} // else 400
} // else 400
} // else 400
} // else 400
} catch (e) {} // 400
response.writeHead(400,{'Content-Length':0,'Pragma':'no-cache','Cache-Control':'no-cache'});
response.end();
return;
});
setInterval(doHousekeeping,5000);
server.setTimeout(120000);
server.listen(HTTP_PORT);
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