socket.io_ip_ua.js

var socketio = require("socket.io");

io.sockets.on("connection", function (socket) {

  // Get client's ip address.
  console.dir(socket.manager.handshaken[socket.id].address.address)
  // Get client's user-agent.
  console.dir(socket.manager.handshaken[socket.id].headers['user-agent'])

}