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package transfer
import (
"context"
"fmt"
"testing"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/dnstest"
"github.com/coredns/coredns/plugin/test"
"github.com/miekg/dns"
)
// transfererPlugin implements transfer.Transferer and plugin.Handler.
type transfererPlugin struct {
Zone string
Serial uint32
Next plugin.Handler
}
// Name implements plugin.Handler.
func (*transfererPlugin) Name() string { return "transfererplugin" }
// ServeDNS implements plugin.Handler.
func (p *transfererPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
if r.Question[0].Name != p.Zone {
return p.Next.ServeDNS(ctx, w, r)
}
return 0, nil
}
// Transfer implements transfer.Transferer - it returns a static AXFR response, or
// if serial is current, an abbreviated IXFR response.
func (p *transfererPlugin) Transfer(zone string, serial uint32) (<-chan []dns.RR, error) {
if zone != p.Zone {
return nil, ErrNotAuthoritative
}
ch := make(chan []dns.RR, 3) // sending 3 bits and don't want to block, nor do a waitgroup
defer close(ch)
ch <- []dns.RR{test.SOA(fmt.Sprintf("%s 100 IN SOA ns.dns.%s hostmaster.%s %d 7200 1800 86400 100", p.Zone, p.Zone, p.Zone, p.Serial))}
if serial >= p.Serial {
return ch, nil
}
ch <- []dns.RR{
test.NS(fmt.Sprintf("%s 100 IN NS ns.dns.%s", p.Zone, p.Zone)),
test.A(fmt.Sprintf("ns.dns.%s 100 IN A 1.2.3.4", p.Zone)),
}
ch <- []dns.RR{test.SOA(fmt.Sprintf("%s 100 IN SOA ns.dns.%s hostmaster.%s %d 7200 1800 86400 100", p.Zone, p.Zone, p.Zone, p.Serial))}
return ch, nil
}
type terminatingPlugin struct{}
// Name implements plugin.Handler.
func (*terminatingPlugin) Name() string { return "testplugin" }
// ServeDNS implements plugin.Handler that returns NXDOMAIN for all requests.
func (*terminatingPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
m := new(dns.Msg)
m.SetRcode(r, dns.RcodeNameError)
w.WriteMsg(m)
return dns.RcodeNameError, nil
}
func newTestTransfer() *Transfer {
nextPlugin1 := transfererPlugin{Zone: "example.com.", Serial: 12345}
nextPlugin2 := transfererPlugin{Zone: "example.org.", Serial: 12345}
nextPlugin2.Next = &terminatingPlugin{}
nextPlugin1.Next = &nextPlugin2
transfer := &Transfer{
Transferers: []Transferer{&nextPlugin1, &nextPlugin2},
xfrs: []*xfr{
{
Zones: []string{"example.org."},
to: []string{"*"},
},
{
Zones: []string{"example.com."},
to: []string{"*"},
},
},
Next: &nextPlugin1,
}
return transfer
}
func TestTransferNonZone(t *testing.T) {
transfer := newTestTransfer()
ctx := context.TODO()
for _, tc := range []string{"sub.example.org.", "example.test."} {
w := dnstest.NewRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetAxfr(tc)
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
if w.Msg == nil {
t.Fatalf("Got nil message for AXFR %s", tc)
}
if w.Msg.Rcode != dns.RcodeNameError {
t.Errorf("Expected NXDOMAIN for AXFR %s got %s", tc, dns.RcodeToString[w.Msg.Rcode])
}
}
}
func TestTransferNotAXFRorIXFR(t *testing.T) {
transfer := newTestTransfer()
ctx := context.TODO()
w := dnstest.NewRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetQuestion("test.domain.", dns.TypeA)
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
if w.Msg == nil {
t.Fatal("Got nil message")
}
if w.Msg.Rcode != dns.RcodeNameError {
t.Errorf("Expected NXDOMAIN got %s", dns.RcodeToString[w.Msg.Rcode])
}
}
func TestTransferAXFRExampleOrg(t *testing.T) {
transfer := newTestTransfer()
ctx := context.TODO()
w := dnstest.NewMultiRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetAxfr(transfer.xfrs[0].Zones[0])
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
validateAXFRResponse(t, w)
}
func TestTransferAXFRExampleCom(t *testing.T) {
transfer := newTestTransfer()
ctx := context.TODO()
w := dnstest.NewMultiRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetAxfr(transfer.xfrs[1].Zones[0])
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
validateAXFRResponse(t, w)
}
func TestTransferIXFRCurrent(t *testing.T) {
transfer := newTestTransfer()
testPlugin := transfer.Transferers[0].(*transfererPlugin)
ctx := context.TODO()
w := dnstest.NewMultiRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetIxfr(transfer.xfrs[0].Zones[0], testPlugin.Serial, "ns.dns."+testPlugin.Zone, "hostmaster.dns."+testPlugin.Zone)
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
if len(w.Msgs) == 0 {
t.Fatal("Did not get back a zone response")
}
if len(w.Msgs[0].Answer) != 1 {
t.Logf("%+v\n", w)
t.Fatalf("Expected 1 answer, got %d", len(w.Msgs[0].Answer))
}
// Ensure the answer is the SOA
if w.Msgs[0].Answer[0].Header().Rrtype != dns.TypeSOA {
t.Error("Answer does not contain the SOA record")
}
}
func TestTransferIXFRFallback(t *testing.T) {
transfer := newTestTransfer()
testPlugin := transfer.Transferers[0].(*transfererPlugin)
ctx := context.TODO()
w := dnstest.NewMultiRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetIxfr(
transfer.xfrs[0].Zones[0],
testPlugin.Serial-1,
"ns.dns."+testPlugin.Zone,
"hostmaster.dns."+testPlugin.Zone,
)
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
validateAXFRResponse(t, w)
}
func validateAXFRResponse(t *testing.T, w *dnstest.MultiRecorder) {
if len(w.Msgs) == 0 {
t.Fatal("Did not get back a zone response")
}
if len(w.Msgs[0].Answer) == 0 {
t.Logf("%+v\n", w)
t.Fatal("Did not get back an answer")
}
// Ensure the answer starts with SOA
if w.Msgs[0].Answer[0].Header().Rrtype != dns.TypeSOA {
t.Error("Answer does not start with SOA record")
}
// Ensure the answer ends with SOA
if w.Msgs[len(w.Msgs)-1].Answer[len(w.Msgs[len(w.Msgs)-1].Answer)-1].Header().Rrtype != dns.TypeSOA {
t.Error("Answer does not end with SOA record")
}
// Ensure the answer is the expected length
c := 0
for _, m := range w.Msgs {
c += len(m.Answer)
}
if c != 4 {
t.Errorf("Answer is not the expected length (expected 4, got %d)", c)
}
}
func TestTransferNotAllowed(t *testing.T) {
nextPlugin := transfererPlugin{Zone: "example.org.", Serial: 12345}
transfer := Transfer{
Transferers: []Transferer{&nextPlugin},
xfrs: []*xfr{
{
Zones: []string{"example.org."},
to: []string{"1.2.3.4"},
},
},
Next: &nextPlugin,
}
ctx := context.TODO()
w := dnstest.NewRecorder(&test.ResponseWriter{TCP: true})
m := &dns.Msg{}
m.SetAxfr(transfer.xfrs[0].Zones[0])
_, err := transfer.ServeDNS(ctx, w, m)
if err != nil {
t.Error(err)
}
if w.Msg.Rcode != dns.RcodeRefused {
t.Errorf("Expected REFUSED response code, got %s", dns.RcodeToString[w.Msg.Rcode])
}
}
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