dns-suite.js/cloud-respond.js

'use strict';

module.exports.respond = function (socket, packets, rinfo) {
  var dns = require('dns-js');
  var os = require('os');
  var queryname = '_cloud._tcp.local';

  console.log(packets);

  packets.forEach(function (packet) {
    packet.question.forEach(function (q) {
      if (queryname !== q.name) {
        return;
      }

      console.log('question', q.name, q.typeName, q.className, q.flag, q);
      var rpacket = new dns.DNSPacket();
      var ifaces = os.networkInterfaces();
      //var llRe = /^(fe80|169)/i; // link-local

      Object.keys(ifaces).forEach(function (iname) {
        var iface = ifaces[iname];

        iface = iface.filter(function (pface) {
          // nix loopback, internal and ipv6 link-local (non-routable) and ipv4 link-local
          return !pface.internal;// && !(pface.scopeid > 1) && !llRe.test(pface.address);
        });

        iface.forEach(function (pface) {
          rpacket.additional.push({
            name: q.name
          , type: ('IPv4' === pface.family ? dns.DNSRecord.Type.A : dns.DNSRecord.Type.AAAA)
          , ttl: 10
          , class: dns.DNSRecord.Class.IN
          , address: pface.address // '_workstation._tcp.local'
          });
        });
      });

      var myRndId = 'be1af7a';
      rpacket.answer.push({
        name: q.name
      , type: dns.DNSRecord.Type.PTR
      , ttl: 10
      , class: dns.DNSRecord.Class.IN
      , data: myRndId + '.' + queryname
      });
      rpacket.question.push(new dns.DNSRecord(
        queryname                           // Name
      , dns.DNSRecord.Type.PTR              // Type
      , dns.DNSRecord.Class.IN              // Class
      //, null                                // TTL
      ));
      rpacket.additional.push({
        name: myRndId + '.' + queryname
      , type: dns.DNSRecord.Type.SRV
      , ttl: 10
      , class: dns.DNSRecord.Class.IN
      , priority: 0
      , weight: 0
      , port: 443
      , target: myRndId + ".local" 
      });
      rpacket.additional.push({
        name: myRndId + '.' + '_device-info._tcp.local'
      , type: dns.DNSRecord.Type.TXT
      , ttl: 10
      , class: dns.DNSRecord.Class.IN
      , data: ["model=CloudHome1,1", "dappsvers=1"]
      });
      rpacket.header.id = packet.header.id;
      rpacket.header.aa = 1;
      rpacket.header.qr = 1;
      rpacket.header.rd = 0;

      console.log('');
      console.log('START JSON PACKET');
      console.log(rpacket);
      var buf = dns.DNSPacket.toBuffer(rpacket);
      console.log(buf.toString('hex'));
      console.log('END JSON PACKET');
      console.log('');

      console.log('');
      console.log('START DNS PACKET');
      var pkt = dns.DNSPacket.parse(buf);
      console.log(pkt);
      console.log('END DNS PACKET');
      console.log('');
      socket.send(buf, rinfo.port, rinfo.address);
    });
    /*
    */
    packet.answer.forEach(function (a) {
      console.log('answer', a.name, a.typeName, a.className, a.flag, a);
    });
    packet.authority.forEach(function (a) {
      console.log('authority', a.name, a.typeName, a.className, a.flag, a);
    });
    packet.additional.forEach(function (a) {
      console.log('additional', a.name, a.typeName, a.className, a.flag, a);
    });
  });
  console.log('\n');
};