dns/_examples/reflect/reflect.go
2011-07-05 14:58:02 +02:00

78 lines
1.9 KiB
Go

/*
* 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")
}
}