Initial code commit

I have no idea what I'm doing in node.js, so this just proves that we can discover and communicate with a Pentair ScreenLogic server on the network. It's super ugly and needs a ton of work, but it's functional.

app.js

@@ -0,0 +1,112 @@
+var dgram = require('dgram'); 
+var net = require('net');
+
+var server = dgram.createSocket("udp4"); 
+server.bind( function() {
+  server.setBroadcast(true)
+  server.setMulticastTTL(128);
+  broadcastNew();
+});
+
+server.on('message', function (message, remote) {
+  console.log('Got a response.');
+  var server = {
+    address: remote.address,
+    type: message.readInt32LE(0),
+    port: message.readInt16LE(8),
+    gatewayType: message.readUInt8(10),
+    gatewaySubtype: message.readUInt8(11),
+    gatewayName: message.toString('utf8', 12, 28)
+  };
+
+  console.log('  type: ' + server.type + ', host: ' + server.address + ':' + server.port + ', identified as ' + server.gatewayName);
+  if (server.type === 2) {
+    connectTo(server);
+  }
+});
+
+function broadcastNew() {
+  var message = new Uint8Array(8);
+  message[0] = 1;
+  server.send(message, 0, message.length, 1444, "255.255.255.255");
+  console.log("Looking for ScreenLogic hosts...");
+}
+
+function connectTo(server) {
+  console.log("connecting...");
+  var client = new net.Socket();
+  client.connect(server.port, server.address, function() {
+    console.log('connected');
+
+    console.log('sending connection string...');
+    var buf = Buffer.from('CONNECTSERVERHOST\r\n\r\n');
+    client.write(buf);
+
+    console.log('sending challenge string...');
+    buf = Buffer.alloc(8);
+    buf.writeUInt16LE(14, 2);
+    client.write(buf);
+
+    console.log('sending login string...');
+    buf = Buffer.alloc(72);
+    buf.writeUInt16LE(0);
+    buf.writeUInt16LE(27, 2);
+    buf.writeInt32LE(64, 4); // length
+    buf.writeInt32LE(348, 8); // schema
+    buf.writeInt32LE(0, 12); // connection type
+    var name = 'ScreenLogicConnect library';
+    buf.writeInt32LE(name.length, 16);
+    buf.write(name, 20);
+    var pos = 20 + name.length;
+    for (var i = 0; i < 4 - (name.length % 4); i++) {
+      buf.writeUInt8(0, 20 + name.length + i);
+      pos = pos + 1;
+    }
+    buf.writeInt32LE(16, pos);
+    pos += 4;
+    pos += 16;
+    buf.writeInt32LE(2, pos);
+    client.write(buf);
+
+    console.log('sending pool status query...');
+    buf = Buffer.alloc(12);
+    buf.writeUInt16LE(12526, 2);
+    buf.writeInt32LE(4, 4);
+    client.write(buf);
+
+    console.log('sending controller config query...');
+    buf = Buffer.alloc(16);
+    buf.writeUInt16LE(12532, 2);
+    buf.writeInt32LE(8, 4);
+    client.write(buf);
+
+    setTimeout(function() {
+      console.log('destroying');
+      client.destroy();
+    }, 3000);
+  });
+
+  client.on('close', function() {
+    console.log('closed');
+  });
+
+  client.on('data', function(msg) {
+    console.log('received message of length ' + msg.length);
+    var msgType = msg.readInt16LE(2);
+    if (msgType === 15) {
+      console.log("  it's a challenge response");
+    } else if (msgType === 28) {
+      console.log("  it's a login response");
+    } else if (msgType === 12527) {
+      console.log("  it's pool status");
+    } else if (msgType === 12533) {
+      console.log("  it's controller configuration");
+    }
+  });
+}
+
+/* debug print full buffer contents:
+for (const value of buf.values()) {
+  console.log(value.toString(16));
+}
+*/