예제 #1
0
func (ts *testSrv) dnsHandler(w dns.ResponseWriter, r *dns.Msg) {
	m := new(dns.Msg)
	m.SetReply(r)
	m.Compress = false

	// Normally this test DNS server will return 127.0.0.1 for everything.
	// However, in some situations (for instance Docker), it's useful to return a
	// different hardcoded host. You can do so by setting the FAKE_DNS environment
	// variable.
	fakeDNS := os.Getenv("FAKE_DNS")
	if fakeDNS == "" {
		fakeDNS = "127.0.0.1"
	}
	for _, q := range r.Question {
		fmt.Printf("dns-srv: Query -- [%s] %s\n", q.Name, dns.TypeToString[q.Qtype])
		switch q.Qtype {
		case dns.TypeA:
			record := new(dns.A)
			record.Hdr = dns.RR_Header{
				Name:   q.Name,
				Rrtype: dns.TypeA,
				Class:  dns.ClassINET,
				Ttl:    0,
			}
			record.A = net.ParseIP(fakeDNS)

			m.Answer = append(m.Answer, record)
		case dns.TypeMX:
			record := new(dns.MX)
			record.Hdr = dns.RR_Header{
				Name:   q.Name,
				Rrtype: dns.TypeMX,
				Class:  dns.ClassINET,
				Ttl:    0,
			}
			record.Mx = "mail." + q.Name
			record.Preference = 10

			m.Answer = append(m.Answer, record)
		case dns.TypeTXT:
			ts.mu.RLock()
			value, present := ts.txtRecords[q.Name]
			ts.mu.RUnlock()
			if !present {
				continue
			}
			record := new(dns.TXT)
			record.Hdr = dns.RR_Header{
				Name:   q.Name,
				Rrtype: dns.TypeTXT,
				Class:  dns.ClassINET,
				Ttl:    0,
			}
			record.Txt = []string{value}
			m.Answer = append(m.Answer, record)
		case dns.TypeCAA:
			if q.Name == "bad-caa-reserved.com." || q.Name == "good-caa-reserved.com." {
				record := new(dns.CAA)
				record.Hdr = dns.RR_Header{
					Name:   q.Name,
					Rrtype: dns.TypeCAA,
					Class:  dns.ClassINET,
					Ttl:    0,
				}
				record.Tag = "issue"
				if q.Name == "bad-caa-reserved.com." {
					record.Value = "sad-hacker-ca.invalid"
				} else if q.Name == "good-caa-reserved.com." {
					record.Value = "happy-hacker-ca.invalid"
				}
				m.Answer = append(m.Answer, record)
			}
		}
	}

	auth := new(dns.SOA)
	auth.Hdr = dns.RR_Header{Name: "boulder.invalid.", Rrtype: dns.TypeSOA, Class: dns.ClassINET, Ttl: 0}
	auth.Ns = "ns.boulder.invalid."
	auth.Mbox = "master.boulder.invalid."
	auth.Serial = 1
	auth.Refresh = 1
	auth.Retry = 1
	auth.Expire = 1
	auth.Minttl = 1
	m.Ns = append(m.Ns, auth)

	w.WriteMsg(m)
	return
}