45 lines
1.1 KiB
Go
45 lines
1.1 KiB
Go
package main
|
|
|
|
// Print the MX records of a domain
|
|
// (c) Miek Gieben - 2011
|
|
import (
|
|
"dns"
|
|
"dns/resolver"
|
|
"os"
|
|
"fmt"
|
|
)
|
|
|
|
func main() {
|
|
r := new(resolver.Resolver)
|
|
qr := resolver.NewQuerier(r)
|
|
r.Servers = []string{"127.0.0.1"}
|
|
r.Timeout = 2
|
|
r.Attempts = 1
|
|
|
|
if len(os.Args) != 2 {
|
|
fmt.Printf("%s DOMAIN\n", os.Args[0])
|
|
os.Exit(1)
|
|
}
|
|
|
|
m := new(dns.Msg)
|
|
m.MsgHdr.Recursion_desired = true //only set this bit
|
|
m.Question = make([]dns.Question, 1)
|
|
m.Question[0] = dns.Question{os.Args[1], dns.TypeMX, dns.ClassINET}
|
|
|
|
qr <- resolver.DnsMsg{m, nil}
|
|
in := <-qr
|
|
|
|
if in.Dns.Rcode != dns.RcodeSuccess {
|
|
fmt.Printf(" *** invalid answer name %s after MX query for %s\n", os.Args[1], os.Args[1])
|
|
os.Exit(1)
|
|
}
|
|
// Stuff must be in the answer section
|
|
for _, a := range in.Dns.Answer {
|
|
fmt.Printf("%v\n", a)
|
|
}
|
|
|
|
// Stop the resolver, send it a null mesg
|
|
qr <- resolver.DnsMsg{nil, nil}
|
|
<-qr
|
|
}
|