/* 
 * A name server which sends back the IP address of its client, the
 * recursive resolver. When queried for type TXT, it sends back the text
 * form of the address.  When queried for type A (resp. AAAA), it sends
 * back the IPv4 (resp. v6) address.
 *
 * Similar services: whoami.ultradns.net, whoami.akamai.net. Also (but it
 * is not their normal goal): rs.dns-oarc.net, porttest.dns-oarc.net,
 * amiopen.openresolvers.org.
 *
 * Stephane Bortzmeyer <stephane+grong@bortzmeyer.org>
 *
 * Adapted to Go DNS (i.e. completely rewritten)
 * Miek Gieben <miek@miek.nl>
 */

package main

import (
	"os"
	"net"
	"dns"
	"fmt"
	"os/signal"
	"strconv"
)

func handleReflect(w dns.ResponseWriter, r *dns.Msg) {
        m := new(dns.Msg)
        m.SetReply(r)
        m.Extra = make([]dns.RR, 1)
	m.Answer = make([]dns.RR, 1)
        fmt.Printf("%v\n", w.conn)
        /* Can't see how the packet came in, v6, v2, udp 
	var ad net.IP
	if c.UDP != nil {
		ad = c.Addr.(*net.UDPAddr).IP
	} else {
		ad = c.Addr.(*net.TCPAddr).IP
	}
        */
}

/*
	if ad.To4() != nil {
		r := new(dns.RR_A)
		r.Hdr = dns.RR_Header{Name: "whoami.miek.nl.", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 0}
		r.A = ad
		m.Answer[0] = r
	} else {
		r := new(dns.RR_AAAA)
		r.Hdr = dns.RR_Header{Name: "whoami.miek.nl.", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: 0}
		r.AAAA = ad
		m.Answer[0] = r
	}

	t := new(dns.RR_TXT)
	t.Hdr = dns.RR_Header{Name: "whoami.miek.nl.", Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: 0}
	if c.TCP != nil {
		t.Txt = "Port: " + strconv.Itoa(c.Port) + " (tcp)"
	} else {
		t.Txt = "Port: " + strconv.Itoa(c.Port) + " (udp)"
	}
	m.Extra[0] = t

	b, _ := m.Pack()
	return b
}
*/

func main() {
        dns.HandleFunc(".", handleReflect)
        err := dns.ListenAndServe(":8053", "udp", nil)
        if err != nil {
                fmt.Printf("Failed to setup the server")
        }
}