68 lines
1.5 KiB
Go
68 lines
1.5 KiB
Go
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package main
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import (
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"fmt"
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"strings"
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"time"
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"github.com/miekg/dns"
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)
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func init() {
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dns.HandleFunc(BASE_DOMAIN, serve)
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}
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func q_String(q dns.Question) string {
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return "" + dns.ClassToString[q.Qclass] + " " + dns.TypeToString[q.Qtype] + " " + q.Name
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}
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func serve(w dns.ResponseWriter, r *dns.Msg) {
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qStr := ""
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for _, q := range r.Question {
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qStr += "\n" + q_String(q)
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}
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fmt.Printf("got question from %s:%s\n", w.RemoteAddr().String(), qStr)
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m := new(dns.Msg)
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defer w.WriteMsg(m)
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if r.Opcode != dns.OpcodeQuery && len(r.Question) != 1 {
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m.SetRcode(r, dns.RcodeRefused)
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return
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}
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q := r.Question[0]
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qName := strings.ToLower(q.Name)
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qKey := qName[0 : len(q.Name)-len(BASE_DOMAIN)]
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m.SetReply(r)
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m.Authoritative = true
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m.Compress = false
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soa := fmt.Sprintf("%s IN SOA %s hostmaster.%s %d 5 1 1 5", qName, DNS_SERVER, DNS_SERVER, (time.Now().Unix() % 4294967295))
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if soaRR, err := dns.NewRR(soa); err == nil {
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m.Ns = append(m.Answer, soaRR)
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}
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if q.Qtype == dns.TypeTXT {
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for _, rData := range db.Lookup(qKey) {
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if rr, err := dns.NewRR(fmt.Sprintf("$TTL 5\n%s TXT %s", qName, rData)); err == nil {
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m.Answer = append(m.Answer, rr)
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} else {
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fmt.Printf("error building rr: %s\n", err)
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}
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}
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rrStr := ""
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for _, rr := range m.Answer {
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rrStr += "\n" + rr.String()
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}
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fmt.Printf("sending response for %s:%s\n", qName, rrStr)
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return
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} else {
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fmt.Printf("no records for name %s\n", qName)
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}
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m.SetRcode(r, dns.RcodeNameError)
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fmt.Printf("%s\n", m.String())
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}
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