code: func (wh Whoami) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
  	state := request.Request{W: w, Req: r}
  
  	a := new(dns.Msg)
  	a.SetReply(r)
  	a.Compress = true
  	a.Authoritative = true
  
  	ip := state.IP()
  	var rr dns.RR
  
  	switch state.Family() {
  	case 1:
  		rr = new(dns.A)
  		rr.(*dns.A).Hdr = dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeA, Class: state.QClass()}
  		rr.(*dns.A).A = net.ParseIP(ip).To4()
  	case 2:
  		rr = new(dns.AAAA)
  		rr.(*dns.AAAA).Hdr = dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeAAAA, Class: state.QClass()}
  		rr.(*dns.AAAA).AAAA = net.ParseIP(ip)
  	}
  
  	srv := new(dns.SRV)
  	srv.Hdr = dns.RR_Header{Name: "_" + state.Proto() + "." + state.QName(), Rrtype: dns.TypeSRV, Class: state.QClass()}
  	if state.QName() == "." {
  		srv.Hdr.Name = "_" + state.Proto() + state.QName()
  	}
  	port, _ := strconv.Atoi(state.Port())
  	srv.Port = uint16(port)
  	srv.Target = "."
  
  	a.Extra = []dns.RR{rr, srv}
  
  	state.SizeAndDo(a)
  	w.WriteMsg(a)
  
  	return 0, nil
  }
docs: // ServeDNS implements the plugin.Handler interface.