dns/_examples/zlutser/zlutser.go
Miek Gieben fc8e6345af Fix examples and add notify prog
Show how simple a dns-notify becomes.
2011-01-08 13:46:51 +01:00

117 lines
2.5 KiB
Go

package main
// Simple prog that "validates" a reply from a
// server, but DOES NOT check the chain of trust!
// lutser is Dutch for prutser and looser combined
// so zlutser does that with zones
import (
"net"
"dns"
"dns/resolver"
"os"
"flag"
"fmt"
"strings"
)
func main() {
var tcp *bool = flag.Bool("tcp", true, "TCP mode")
var port *string = flag.String("port", "53", "Set the query port")
var zone *string = flag.String("zone", "", "Zone to ask the DNSKEYs for")
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage: %s -z zone [@server] [qtype] [name ...]\n", os.Args[0])
// extend this a little
flag.PrintDefaults()
}
nameserver := "@127.0.0.1" // Default nameserver
qtype := uint16(dns.TypeA) // Default qtype
var qname []string
flag.Parse()
if *zone == "" {
fmt.Fprintf(os.Stderr, "%s: -zone is mandatory\n", os.Args[0])
os.Exit(1)
}
FLAGS:
for i := 0; i < flag.NArg(); i++ {
// If it starts with @ it is a nameserver
if flag.Arg(i)[0] == '@' {
nameserver = flag.Arg(i)
continue FLAGS
}
// If it looks like type, it is a type
for k, v := range dns.Rr_str {
if v == strings.ToUpper(flag.Arg(i)) {
qtype = k
continue FLAGS
}
}
// Anything else is a qname
qname = append(qname, flag.Arg(i))
}
r := new(resolver.Resolver)
r.Timeout = 2
r.Port = *port
r.Tcp = *tcp
r.Attempts = 1
qr := r.NewQuerier()
// @server may be a name, resolv that
var err os.Error
nameserver = string([]byte(nameserver)[1:]) // chop off @
_, addr, err := net.LookupHost(nameserver)
if err == nil {
r.Servers = addr
} else {
r.Servers = []string{nameserver}
}
m := new(dns.Msg)
// m.MsgHdr.Authoritative = *aa
// m.MsgHdr.AuthenticatedData = *ad
m.MsgHdr.CheckingDisabled = true
m.MsgHdr.RecursionDesired = true
m.Question = make([]dns.Question, 1)
// set the do bit
opt := new(dns.RR_OPT)
opt.Hdr = dns.RR_Header{Name: "", Rrtype: dns.TypeOPT}
opt.SetVersion(0)
opt.SetDo()
opt.SetUDPSize(4096)
m.Extra = make([]dns.RR, 1)
m.Extra[0] = opt
for _, v := range qname {
// Ask the Keys
m.Question[0] = dns.Question{*zone, dns.TypeDNSKEY, dns.ClassINET}
qr <- resolver.DnsMsg{m, nil}
in := <-qr
if in.Dns != nil {
fmt.Printf("%v\n", in.Dns)
}
m.Question[0] = dns.Question{v, qtype, dns.ClassINET}
qr <- resolver.DnsMsg{m, nil}
in = <-qr
if in.Dns != nil {
fmt.Printf("%v\n", in.Dns)
}
// Ask the question
// Get the sig(s)
// Use the key(s)
// Validate
}
qr <- resolver.DnsMsg{nil, nil}
<-qr
}