dns/_examples/chaos/chaos.go

78 lines
1.8 KiB
Go

package main
// Print the version.bind and hostname.bind for each
// address of NAMESERVER
// (c) Miek Gieben - 2011
import (
"dns"
"os"
"fmt"
)
func main() {
c, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
if len(os.Args) != 2 {
fmt.Printf("%s DOMAIN\n", os.Args[0])
os.Exit(1)
}
m := new(dns.Msg)
m.Question = make([]dns.Question, 1)
d := new(dns.Conn)
d.RemoteAddr = c.Servers[0]
for _, a := range addresses(d, os.Args[0]) {
d.RemoteAddr = a
if err := d.Dial("udp"); err != nil {
fmt.Printf("%v\n", err)
os.Exit(1)
}
m.Question[0] = dns.Question{"version.bind.", dns.TypeTXT, dns.ClassCHAOS}
in, _ := dns.SimpleQuery("udp", d, m)
if in != nil && in.Answer != nil {
fmt.Printf("%v\n", in.Answer[0])
}
m.Question[0] = dns.Question{"hostname.bind.", dns.TypeTXT, dns.ClassCHAOS}
in, _ = dns.SimpleQuery("udp", d, m)
if in != nil && in.Answer != nil {
fmt.Printf("%v\n", in.Answer[0])
}
}
}
func addresses(d *dns.Conn, name string) []string {
m := new(dns.Msg)
m.MsgHdr.RecursionDesired = true //only set this bit
m.Question = make([]dns.Question, 1)
var ips []string
m.Question[0] = dns.Question{os.Args[1], dns.TypeA, dns.ClassINET}
in, err := dns.SimpleQuery("udp", d, m)
if in == nil {
fmt.Printf("Nothing recevied: %s\n", err.String())
return nil
}
if in.Rcode != dns.RcodeSuccess {
return nil
}
// Stuff must be in the answer section
for _, a := range in.Answer {
ips = append(ips, a.(*dns.RR_A).A.String()+":53")
}
m.Question[0] = dns.Question{os.Args[1], dns.TypeAAAA, dns.ClassINET}
in, err = dns.SimpleQuery("udp", d, m)
if in == nil {
fmt.Printf("Nothing recevied: %s\n", err.String())
return ips
}
if in.Rcode != dns.RcodeSuccess {
return ips
}
for _, a := range in.Answer {
ips = append(ips, "["+a.(*dns.RR_AAAA).AAAA.String()+"]:53")
}
return ips
}