Files
coredns/request/request_test.go
Miek Gieben 62df253371 request: re-adjust size for edns0 RR (#2007)
* Add regression test for broken DNS truncation

With the latest changes to the implementation, request.Scrub() returns
invalid response messages which are larger than the advertised buffer
size. This commit adds a failing test for that.

* Add benchmark for response truncation

* request: re-adjust size for edns0 RR

Cherry-picked the test and benchmark commits from #1962 and make the
failing test not fail, by adding minimal fix in request.go.

This makes size 12 bytes smaller if we need to add back the OPT RR in
the message.

Closes: #1962

Signed-off-by: Miek Gieben <miek@miek.nl>

* Scrub: correctly check for EDNS0, not only Do

Make Scrub check for EDNS0, not only if the Do bit is set.

Signed-off-by: Miek Gieben <miek@miek.nl>
2018-07-28 10:27:38 +01:00

277 lines
7.0 KiB
Go

package request
import (
"fmt"
"testing"
"github.com/coredns/coredns/plugin/test"
"github.com/miekg/dns"
)
func TestRequestDo(t *testing.T) {
st := testRequest()
st.Do()
if st.do == nil {
t.Errorf("Expected st.do to be set")
}
}
func TestRequestRemote(t *testing.T) {
st := testRequest()
if st.IP() != "10.240.0.1" {
t.Errorf("Wrong IP from request")
}
p := st.Port()
if p == "" {
t.Errorf("Failed to get Port from request")
}
if p != "40212" {
t.Errorf("Wrong port from request")
}
}
func TestRequestMalformed(t *testing.T) {
m := new(dns.Msg)
st := Request{Req: m}
if x := st.QType(); x != 0 {
t.Errorf("Expected 0 Qtype, got %d", x)
}
if x := st.QClass(); x != 0 {
t.Errorf("Expected 0 QClass, got %d", x)
}
if x := st.QName(); x != "." {
t.Errorf("Expected . Qname, got %s", x)
}
if x := st.Name(); x != "." {
t.Errorf("Expected . Name, got %s", x)
}
if x := st.Type(); x != "" {
t.Errorf("Expected empty Type, got %s", x)
}
if x := st.Class(); x != "" {
t.Errorf("Expected empty Class, got %s", x)
}
}
func TestRequestScrubAnswer(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("large.example.com.", dns.TypeSRV)
req := Request{W: &test.ResponseWriter{}, Req: m}
reply := new(dns.Msg)
reply.SetReply(m)
for i := 1; i < 200; i++ {
reply.Answer = append(reply.Answer, test.SRV(
fmt.Sprintf("large.example.com. 10 IN SRV 0 0 80 10-0-0-%d.default.pod.k8s.example.com.", i)))
}
_, got := req.Scrub(reply)
if want := ScrubAnswer; want != got {
t.Errorf("Want scrub result %d, got %d", want, got)
}
if want, got := req.Size(), reply.Len(); want < got {
t.Errorf("Want scrub to reduce message length below %d bytes, got %d bytes", want, got)
}
if !reply.Truncated {
t.Errorf("Want scrub to set truncated bit")
}
}
func TestRequestScrubExtra(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("large.example.com.", dns.TypeSRV)
req := Request{W: &test.ResponseWriter{}, Req: m}
reply := new(dns.Msg)
reply.SetReply(m)
for i := 1; i < 200; i++ {
reply.Extra = append(reply.Extra, test.SRV(
fmt.Sprintf("large.example.com. 10 IN SRV 0 0 80 10-0-0-%d.default.pod.k8s.example.com.", i)))
}
_, got := req.Scrub(reply)
if want := ScrubExtra; want != got {
t.Errorf("Want scrub result %d, got %d", want, got)
}
if want, got := req.Size(), reply.Len(); want < got {
t.Errorf("Want scrub to reduce message length below %d bytes, got %d bytes", want, got)
}
if reply.Truncated {
t.Errorf("Want scrub to not set truncated bit")
}
}
func TestRequestScrubExtraEdns0(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("large.example.com.", dns.TypeSRV)
m.SetEdns0(4096, true)
req := Request{W: &test.ResponseWriter{}, Req: m}
reply := new(dns.Msg)
reply.SetReply(m)
for i := 1; i < 200; i++ {
reply.Extra = append(reply.Extra, test.SRV(
fmt.Sprintf("large.example.com. 10 IN SRV 0 0 80 10-0-0-%d.default.pod.k8s.example.com.", i)))
}
_, got := req.Scrub(reply)
if want := ScrubExtra; want != got {
t.Errorf("Want scrub result %d, got %d", want, got)
}
if want, got := req.Size(), reply.Len(); want < got {
t.Errorf("Want scrub to reduce message length below %d bytes, got %d bytes", want, got)
}
if reply.Truncated {
t.Errorf("Want scrub to not set truncated bit")
}
opt := reply.Extra[len(reply.Extra)-1]
if opt.Header().Rrtype != dns.TypeOPT {
t.Errorf("Last RR must be OPT record")
}
}
func TestRequestScrubExtraRegression(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("large.example.com.", dns.TypeSRV)
m.SetEdns0(2048, true)
req := Request{W: &test.ResponseWriter{}, Req: m}
reply := new(dns.Msg)
reply.SetReply(m)
for i := 1; i < 33; i++ {
reply.Answer = append(reply.Answer, test.SRV(
fmt.Sprintf("large.example.com. 10 IN SRV 0 0 80 10-0-0-%d.default.pod.k8s.example.com.", i)))
}
for i := 1; i < 33; i++ {
reply.Extra = append(reply.Extra, test.A(
fmt.Sprintf("10-0-0-%d.default.pod.k8s.example.com. 10 IN A 10.0.0.%d", i, i)))
}
_, got := req.Scrub(reply)
if want := ScrubExtra; want != got {
t.Errorf("Want scrub result %d, got %d", want, got)
}
if want, got := req.Size(), reply.Len(); want < got {
t.Errorf("Want scrub to reduce message length below %d bytes, got %d bytes", want, got)
}
if reply.Truncated {
t.Errorf("Want scrub to not set truncated bit")
}
opt := reply.Extra[len(reply.Extra)-1]
if opt.Header().Rrtype != dns.TypeOPT {
t.Errorf("Last RR must be OPT record")
}
}
func TestRequestScrubAnswerExact(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("large.example.com.", dns.TypeSRV)
m.SetEdns0(867, false) // Bit fiddly, but this hits the rl == size break clause in Scrub, 52 RRs should remain.
req := Request{W: &test.ResponseWriter{}, Req: m}
reply := new(dns.Msg)
reply.SetReply(m)
for i := 1; i < 200; i++ {
reply.Answer = append(reply.Answer, test.A(fmt.Sprintf("large.example.com. 10 IN A 127.0.0.%d", i)))
}
_, got := req.Scrub(reply)
if want := ScrubAnswer; want != got {
t.Errorf("Want scrub result %d, got %d", want, got)
}
if want, got := req.Size(), reply.Len(); want < got {
t.Errorf("Want scrub to reduce message length below %d bytes, got %d bytes", want, got)
}
}
func TestRequestMatch(t *testing.T) {
st := testRequest()
reply := new(dns.Msg)
reply.Response = true
reply.SetQuestion("example.com.", dns.TypeMX)
if b := st.Match(reply); b {
t.Errorf("Failed to match %s %d, got %t, expected %t", "example.com.", dns.TypeMX, b, false)
}
reply.SetQuestion("example.com.", dns.TypeA)
if b := st.Match(reply); !b {
t.Errorf("Failed to match %s %d, got %t, expected %t", "example.com.", dns.TypeA, b, true)
}
reply.SetQuestion("example.org.", dns.TypeA)
if b := st.Match(reply); b {
t.Errorf("Failed to match %s %d, got %t, expected %t", "example.org.", dns.TypeA, b, false)
}
}
func BenchmarkRequestDo(b *testing.B) {
st := testRequest()
for i := 0; i < b.N; i++ {
st.Do()
}
}
func BenchmarkRequestSize(b *testing.B) {
st := testRequest()
for i := 0; i < b.N; i++ {
st.Size()
}
}
func BenchmarkRequestScrub(b *testing.B) {
st := testRequest()
reply := new(dns.Msg)
reply.SetReply(st.Req)
for i := 1; i < 33; i++ {
reply.Answer = append(reply.Answer, test.SRV(
fmt.Sprintf("large.example.com. 10 IN SRV 0 0 80 10-0-0-%d.default.pod.k8s.example.com.", i)))
}
for i := 1; i < 33; i++ {
reply.Extra = append(reply.Extra, test.A(
fmt.Sprintf("10-0-0-%d.default.pod.k8s.example.com. 10 IN A 10.0.0.%d", i, i)))
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
st.Scrub(reply.Copy())
}
}
func testRequest() Request {
m := new(dns.Msg)
m.SetQuestion("example.com.", dns.TypeA)
m.SetEdns0(4096, true)
return Request{W: &test.ResponseWriter{}, Req: m}
}
func TestRequestClear(t *testing.T) {
st := testRequest()
if st.IP() != "10.240.0.1" {
t.Errorf("Wrong IP from request")
}
p := st.Port()
if p == "" {
t.Errorf("Failed to get Port from request")
}
st.Clear()
if st.ip != "" {
t.Errorf("Expected st.ip to be cleared after Clear")
}
if st.port != "" {
t.Errorf("Expected st.port to be cleared after Clear")
}
}