func (r *DNSProvider) changeRecord(action, fqdn, value string, ttl int) error {
// Find the zone for the given fqdn
zone, err := acme.FindZoneByFqdn(fqdn, []string{r.nameserver})
if err != nil {
return err
}
// Create RR
rr := new(dns.TXT)
rr.Hdr = dns.RR_Header{Name: fqdn, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: uint32(ttl)}
rr.Txt = []string{value}
rrs := []dns.RR{rr}
// Create dynamic update packet
m := new(dns.Msg)
m.SetUpdate(zone)
switch action {
case "INSERT":
// Always remove old challenge left over from who knows what.
m.RemoveRRset(rrs)
m.Insert(rrs)
case "REMOVE":
m.Remove(rrs)
default:
return fmt.Errorf("Unexpected action: %s", action)
}
// Setup client
c := new(dns.Client)
c.SingleInflight = true
// TSIG authentication / msg signing
if len(r.tsigKey) > 0 && len(r.tsigSecret) > 0 {
m.SetTsig(dns.Fqdn(r.tsigKey), r.tsigAlgorithm, 300, time.Now().Unix())
c.TsigSecret = map[string]string{dns.Fqdn(r.tsigKey): r.tsigSecret}
}
// Send the query
reply, _, err := c.Exchange(m, r.nameserver)
if err != nil {
return fmt.Errorf("DNS update failed: %v", err)
}
if reply != nil && reply.Rcode != dns.RcodeSuccess {
return fmt.Errorf("DNS update failed. Server replied: %s", dns.RcodeToString[reply.Rcode])
}
return nil
}
func (s *jujuNameServer) handleRequest(w dns.ResponseWriter, r *dns.Msg) {
m := new(dns.Msg)
m.SetReply(r)
for _, q := range r.Question {
rr, err := s.answer(q)
if err != nil {
m.SetRcodeFormatError(r)
t := new(dns.TXT)
t.Hdr = dns.RR_Header{
Name: q.Name,
Rrtype: dns.TypeTXT,
Class: dns.ClassNONE,
}
t.Txt = []string{err.Error()}
m.Extra = append(m.Extra, t)
continue
} else if rr != nil {
m.Answer = append(m.Answer, rr)
}
}
m.Authoritative = true
// recursion isn't really available, but it's apparently
// necessary to set this to make nslookup happy.
m.RecursionAvailable = true
w.WriteMsg(m)
}
func Stats_dns_message(message *dns.Msg, writer dns.ResponseWriter) *dns.Msg {
for _, stat := range runtime_stats() {
txtRR := new(dns.TXT)
txtRR.Hdr = dns.RR_Header{Name: conf.Stats_uri, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: 0}
txtRR.Txt = []string{stat}
message.Answer = append(message.Answer, txtRR)
}
return message
}
func TestRFC2136ValidUpdatePacket(t *testing.T) {
dns.HandleFunc(rfc2136TestZone, serverHandlerPassBackRequest)
defer dns.HandleRemove(rfc2136TestZone)
server, addrstr, err := runLocalDNSTestServer("127.0.0.1:0", false)
if err != nil {
t.Fatalf("Failed to start test server: %v", err)
}
defer server.Shutdown()
rr := new(dns.TXT)
rr.Hdr = dns.RR_Header{
Name: rfc2136TestFqdn,
Rrtype: dns.TypeTXT,
Class: dns.ClassINET,
Ttl: uint32(rfc2136TestTTL),
}
rr.Txt = []string{rfc2136TestValue}
rrs := make([]dns.RR, 1)
rrs[0] = rr
m := new(dns.Msg)
m.SetUpdate(dns.Fqdn(rfc2136TestZone))
m.Insert(rrs)
expectstr := m.String()
expect, err := m.Pack()
if err != nil {
t.Fatalf("Error packing expect msg: %v", err)
}
provider, err := NewDNSProviderRFC2136(addrstr, rfc2136TestZone, "", "")
if err != nil {
t.Fatalf("Expected NewDNSProviderRFC2136() to return no error but the error was -> %v", err)
}
if err := provider.Present(rfc2136TestDomain, "", "1234d=="); err != nil {
t.Errorf("Expected Present() to return no error but the error was -> %v", err)
}
rcvMsg := <-reqChan
rcvMsg.Id = m.Id
actual, err := rcvMsg.Pack()
if err != nil {
t.Fatalf("Error packing actual msg: %v", err)
}
if !bytes.Equal(actual, expect) {
tmp := new(dns.Msg)
if err := tmp.Unpack(actual); err != nil {
t.Fatalf("Error unpacking actual msg: %v", err)
}
t.Errorf("Expected msg:\n%s", expectstr)
t.Errorf("Actual msg:\n%v", tmp)
}
}
func errorToTxt(err error) dns.RR {
if err == nil {
return nil
}
msg := err.Error()
if len(msg) > 255 {
msg = msg[:255]
}
t := new(dns.TXT)
t.Hdr.Class = dns.ClassCHAOS
t.Hdr.Ttl = 0
t.Hdr.Rrtype = dns.TypeTXT
t.Hdr.Name = "."
t.Txt = []string{msg}
return t
}
// RR returns an RR representation of s. It is in a condensed form to minimize space
// when this is returned in a DNS message.
// The RR will look like:
// 1.rails.production.east.skydns.local. 300 CH TXT "service1.example.com:8080(10,0,,false)[0,]"
// etcd Key Ttl Host:Port < see below >
// between parens: (Priority, Weight, Text (only first 200 bytes!), Mail)
// between blockquotes: [TargetStrip,Group]
// If the record is synthesised by CoreDNS (i.e. no lookup in etcd happened):
//
// TODO(miek): what to put here?
//
func (s *Service) RR() *dns.TXT {
l := len(s.Text)
if l > 200 {
l = 200
}
t := new(dns.TXT)
t.Hdr.Class = dns.ClassCHAOS
t.Hdr.Ttl = s.Ttl
t.Hdr.Rrtype = dns.TypeTXT
t.Hdr.Name = Domain(s.Key)
t.Txt = make([]string, 1)
t.Txt[0] = fmt.Sprintf("%s:%d(%d,%d,%s,%t)[%d,%s]",
s.Host, s.Port,
s.Priority, s.Weight, s.Text[:l], s.Mail,
s.TargetStrip, s.Group)
return t
}
func route(w dns.ResponseWriter, req *dns.Msg) {
if len(req.Question) != 1 {
failWithRcode(w, req, dns.RcodeRefused)
return
}
question := req.Question[0]
qtype := question.Qtype
if question.Qclass != dns.ClassINET {
failWithRcode(w, req, dns.RcodeRefused)
return
}
remoteIP := w.RemoteAddr().(*net.UDPAddr).IP
m := new(dns.Msg)
m.Id = req.Id
switch qtype {
case dns.TypeA:
if remoteIP4 := remoteIP.To4(); remoteIP4 != nil {
rr := new(dns.A)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
Class: dns.ClassINET, Ttl: 10}
rr.A = remoteIP4
m.Answer = []dns.RR{rr}
}
case dns.TypeAAAA:
if remoteIP16 := remoteIP.To16(); remoteIP16 != nil {
rr := new(dns.AAAA)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
Class: dns.ClassINET, Ttl: 10}
rr.AAAA = remoteIP16
m.Answer = []dns.RR{rr}
}
case dns.TypeTXT:
rr := new(dns.TXT)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
Class: dns.ClassINET, Ttl: 10}
rr.Txt = []string{fmt.Sprintf("Resolver IP: %v", remoteIP.String())}
m.Answer = []dns.RR{rr}
}
m.Question = req.Question
m.Response = true
m.Authoritative = true
w.WriteMsg(m)
}
func (r *DNSProviderRFC2136) changeRecord(action, fqdn, value string, ttl int) error {
// Create RR
rr := new(dns.TXT)
rr.Hdr = dns.RR_Header{Name: fqdn, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: uint32(ttl)}
rr.Txt = []string{value}
rrs := make([]dns.RR, 1)
rrs[0] = rr
// Create dynamic update packet
m := new(dns.Msg)
m.SetUpdate(dns.Fqdn(r.zone))
switch action {
case "INSERT":
m.Insert(rrs)
case "REMOVE":
m.Remove(rrs)
default:
return fmt.Errorf("Unexpected action: %s", action)
}
// Setup client
c := new(dns.Client)
c.SingleInflight = true
// TSIG authentication / msg signing
if len(r.tsigKey) > 0 && len(r.tsigSecret) > 0 {
m.SetTsig(dns.Fqdn(r.tsigKey), dns.HmacMD5, 300, time.Now().Unix())
c.TsigSecret = map[string]string{dns.Fqdn(r.tsigKey): r.tsigSecret}
}
// Send the query
reply, _, err := c.Exchange(m, r.nameserver)
if err != nil {
return fmt.Errorf("DNS update failed: %v", err)
}
if reply != nil && reply.Rcode != dns.RcodeSuccess {
return fmt.Errorf("DNS update failed. Server replied: %s", dns.RcodeToString[reply.Rcode])
}
return nil
}
func answerTXT(q dns.Question, value string) dns.RR {
answer := new(dns.TXT)
answer.Header().Name = q.Name
answer.Header().Rrtype = dns.TypeTXT
answer.Header().Class = dns.ClassINET
answer.Txt = []string{value}
return answer
}
func processWOL(cfg *Config, q *dns.Question) dns.RR {
hostname := getWOLHostname(q)
log.Printf("WoL requested for %s", hostname)
err := wakeByHostname(cfg, hostname)
status := "OKAY"
if err != nil {
status = err.Error()
}
answer := new(dns.TXT)
answer.Header().Name = q.Name
answer.Header().Rrtype = dns.TypeTXT
answer.Header().Class = dns.ClassINET
answer.Txt = []string{status}
return answer
}
func handleReflect(w dns.ResponseWriter, r *dns.Msg) {
var (
v4 bool
rr dns.RR
str string
a net.IP
)
// TC must be done here
m := new(dns.Msg)
m.SetReply(r)
m.Compress = *compress
if ip, ok := w.RemoteAddr().(*net.UDPAddr); ok {
str = "Port: " + strconv.Itoa(ip.Port) + " (udp)"
a = ip.IP
v4 = a.To4() != nil
}
if ip, ok := w.RemoteAddr().(*net.TCPAddr); ok {
str = "Port: " + strconv.Itoa(ip.Port) + " (tcp)"
a = ip.IP
v4 = a.To4() != nil
}
/*
if o := r.IsEdns0(); o != nil {
for _, s := range o.Option {
switch e := s.(type) {
case *dns.EDNS0_SUBNET:
log.Printf("Edns0 subnet %s", e.Address)
}
}
}
*/
if v4 {
rr = new(dns.A)
rr.(*dns.A).Hdr = dns.RR_Header{Name: dom, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 0}
rr.(*dns.A).A = a.To4()
} else {
rr = new(dns.AAAA)
rr.(*dns.AAAA).Hdr = dns.RR_Header{Name: dom, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: 0}
rr.(*dns.AAAA).AAAA = a
}
t := new(dns.TXT)
t.Hdr = dns.RR_Header{Name: dom, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: 0}
t.Txt = []string{str}
switch r.Question[0].Qtype {
case dns.TypeAXFR:
c := make(chan *dns.Envelope)
var e *error
if err := dns.TransferOut(w, r, c, e); err != nil {
close(c)
return
}
soa, _ := dns.NewRR(`whoami.miek.nl. IN SOA elektron.atoom.net. miekg.atoom.net. (
2009032802
21600
7200
604800
3600)`)
c <- &dns.Envelope{RR: []dns.RR{soa, t, rr, soa}}
close(c)
w.Hijack()
// w.Close() // Client closes
return
case dns.TypeTXT:
m.Answer = append(m.Answer, t)
m.Extra = append(m.Extra, rr)
default:
fallthrough
case dns.TypeAAAA, dns.TypeA:
m.Answer = append(m.Answer, rr)
m.Extra = append(m.Extra, t)
}
if r.IsTsig() != nil {
if w.TsigStatus() == nil {
m.SetTsig(r.Extra[len(r.Extra)-1].(*dns.TSIG).Hdr.Name, dns.HmacMD5, 300, time.Now().Unix())
} else {
println("Status", w.TsigStatus().Error())
}
}
if *printf {
fmt.Printf("%v\n", m.String())
}
w.WriteMsg(m)
}
func handleReflect(w dns.ResponseWriter, r *dns.Msg) {
reflectHandled += 1
if reflectHandled%1000 == 0 {
fmt.Printf("Served %d reflections\n", reflectHandled)
}
var (
v4 bool
rr dns.RR
str string
a net.IP
)
m := new(dns.Msg)
m.SetReply(r)
m.Compress = *compress
if ip, ok := w.RemoteAddr().(*net.UDPAddr); ok {
str = "Port: " + strconv.Itoa(ip.Port) + " (udp)"
a = ip.IP
v4 = a.To4() != nil
}
if ip, ok := w.RemoteAddr().(*net.TCPAddr); ok {
str = "Port: " + strconv.Itoa(ip.Port) + " (tcp)"
a = ip.IP
v4 = a.To4() != nil
}
if v4 {
rr = new(dns.A)
rr.(*dns.A).Hdr = dns.RR_Header{Name: dom, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 0}
rr.(*dns.A).A = a.To4()
} else {
rr = new(dns.AAAA)
rr.(*dns.AAAA).Hdr = dns.RR_Header{Name: dom, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: 0}
rr.(*dns.AAAA).AAAA = a
}
t := new(dns.TXT)
t.Hdr = dns.RR_Header{Name: dom, Rrtype: dns.TypeTXT, Class: dns.ClassINET, Ttl: 0}
t.Txt = []string{str}
switch r.Question[0].Qtype {
case dns.TypeTXT:
m.Answer = append(m.Answer, t)
m.Extra = append(m.Extra, rr)
default:
fallthrough
case dns.TypeAAAA, dns.TypeA:
m.Answer = append(m.Answer, rr)
m.Extra = append(m.Extra, t)
case dns.TypeAXFR, dns.TypeIXFR:
c := make(chan *dns.Envelope)
tr := new(dns.Transfer)
defer close(c)
err := tr.Out(w, r, c)
if err != nil {
return
}
soa, _ := dns.NewRR(`whoami.miek.nl. 0 IN SOA linode.atoom.net. miek.miek.nl. 2009032802 21600 7200 604800 3600`)
c <- &dns.Envelope{RR: []dns.RR{soa, t, rr, soa}}
w.Hijack()
// w.Close() // Client closes connection
return
}
if r.IsTsig() != nil {
if w.TsigStatus() == nil {
m.SetTsig(r.Extra[len(r.Extra)-1].(*dns.TSIG).Hdr.Name, dns.HmacMD5, 300, time.Now().Unix())
} else {
println("Status", w.TsigStatus().Error())
}
}
if *printf {
fmt.Printf("%v\n", m.String())
}
// set TC when question is tc.miek.nl.
if m.Question[0].Name == "tc.miek.nl." {
m.Truncated = true
// send half a message
buf, _ := m.Pack()
w.Write(buf[:len(buf)/2])
return
}
w.WriteMsg(m)
}