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tailscale/wgengine/tsdns/tsdns_test.go

751 lines
19 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tsdns
import (
"bytes"
"errors"
"net"
"sync"
"testing"
dns "golang.org/x/net/dns/dnsmessage"
"inet.af/netaddr"
"tailscale.com/tstest"
)
var testipv4 = netaddr.IPv4(1, 2, 3, 4)
var testipv6 = netaddr.IPv6Raw([16]byte{
0x00, 0x01, 0x02, 0x03,
0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b,
0x0c, 0x0d, 0x0e, 0x0f,
})
var dnsMap = NewMap(
map[string]netaddr.IP{
"test1.ipn.dev.": testipv4,
"test2.ipn.dev.": testipv6,
},
[]string{"ipn.dev."},
)
func dnspacket(domain string, tp dns.Type) []byte {
var dnsHeader dns.Header
question := dns.Question{
Name: dns.MustNewName(domain),
Type: tp,
Class: dns.ClassINET,
}
builder := dns.NewBuilder(nil, dnsHeader)
builder.StartQuestions()
builder.Question(question)
payload, _ := builder.Finish()
return payload
}
type dnsResponse struct {
ip netaddr.IP
name string
rcode dns.RCode
}
func unpackResponse(payload []byte) (dnsResponse, error) {
var response dnsResponse
var parser dns.Parser
h, err := parser.Start(payload)
if err != nil {
return response, err
}
if !h.Response {
return response, errors.New("not a response")
}
response.rcode = h.RCode
if response.rcode != dns.RCodeSuccess {
return response, nil
}
err = parser.SkipAllQuestions()
if err != nil {
return response, err
}
ah, err := parser.AnswerHeader()
if err != nil {
return response, err
}
switch ah.Type {
case dns.TypeA:
res, err := parser.AResource()
if err != nil {
return response, err
}
response.ip = netaddr.IPv4(res.A[0], res.A[1], res.A[2], res.A[3])
case dns.TypeAAAA:
res, err := parser.AAAAResource()
if err != nil {
return response, err
}
response.ip = netaddr.IPv6Raw(res.AAAA)
case dns.TypeNS:
res, err := parser.NSResource()
if err != nil {
return response, err
}
response.name = res.NS.String()
default:
return response, errors.New("type not in {A, AAAA, NS}")
}
return response, nil
}
func syncRespond(r *Resolver, query []byte) ([]byte, error) {
request := Packet{Payload: query}
r.EnqueueRequest(request)
resp, err := r.NextResponse()
return resp.Payload, err
}
func mustIP(str string) netaddr.IP {
ip, err := netaddr.ParseIP(str)
if err != nil {
panic(err)
}
return ip
}
func TestRDNSNameToIPv4(t *testing.T) {
tests := []struct {
name string
input string
wantIP netaddr.IP
wantOK bool
}{
{"valid", "4.123.24.1.in-addr.arpa.", netaddr.IPv4(1, 24, 123, 4), true},
{"double_dot", "1..2.3.in-addr.arpa.", netaddr.IP{}, false},
{"overflow", "1.256.3.4.in-addr.arpa.", netaddr.IP{}, false},
{"not_ip", "sub.do.ma.in.in-addr.arpa.", netaddr.IP{}, false},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ip, ok := rdnsNameToIPv4(tt.input)
if ok != tt.wantOK {
t.Errorf("ok = %v; want %v", ok, tt.wantOK)
} else if ok && ip != tt.wantIP {
t.Errorf("ip = %v; want %v", ip, tt.wantIP)
}
})
}
}
func TestRDNSNameToIPv6(t *testing.T) {
tests := []struct {
name string
input string
wantIP netaddr.IP
wantOK bool
}{
{
"valid",
"b.a.9.8.7.6.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.",
mustIP("2001:db8::567:89ab"),
true,
},
{
"double_dot",
"b..9.8.7.6.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.",
netaddr.IP{},
false,
},
{
"double_hex",
"b.a.98.0.7.6.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.",
netaddr.IP{},
false,
},
{
"not_hex",
"b.a.g.0.7.6.5.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa.",
netaddr.IP{},
false,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ip, ok := rdnsNameToIPv6(tt.input)
if ok != tt.wantOK {
t.Errorf("ok = %v; want %v", ok, tt.wantOK)
} else if ok && ip != tt.wantIP {
t.Errorf("ip = %v; want %v", ip, tt.wantIP)
}
})
}
}
func TestResolve(t *testing.T) {
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: false})
r.SetMap(dnsMap)
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
tests := []struct {
name string
qname string
qtype dns.Type
ip netaddr.IP
code dns.RCode
}{
{"ipv4", "test1.ipn.dev.", dns.TypeA, testipv4, dns.RCodeSuccess},
{"ipv6", "test2.ipn.dev.", dns.TypeAAAA, testipv6, dns.RCodeSuccess},
{"no-ipv6", "test1.ipn.dev.", dns.TypeAAAA, netaddr.IP{}, dns.RCodeSuccess},
{"nxdomain", "test3.ipn.dev.", dns.TypeA, netaddr.IP{}, dns.RCodeNameError},
{"foreign domain", "google.com.", dns.TypeA, netaddr.IP{}, dns.RCodeRefused},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ip, code, err := r.Resolve(tt.qname, tt.qtype)
if err != nil {
t.Errorf("err = %v; want nil", err)
}
if code != tt.code {
t.Errorf("code = %v; want %v", code, tt.code)
}
// Only check ip for non-err
if ip != tt.ip {
t.Errorf("ip = %v; want %v", ip, tt.ip)
}
})
}
}
func TestResolveReverse(t *testing.T) {
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: false})
r.SetMap(dnsMap)
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
tests := []struct {
name string
ip netaddr.IP
want string
code dns.RCode
}{
{"ipv4", testipv4, "test1.ipn.dev.", dns.RCodeSuccess},
{"ipv6", testipv6, "test2.ipn.dev.", dns.RCodeSuccess},
{"nxdomain", netaddr.IPv4(4, 3, 2, 1), "", dns.RCodeNameError},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
name, code, err := r.ResolveReverse(tt.ip)
if err != nil {
t.Errorf("err = %v; want nil", err)
}
if code != tt.code {
t.Errorf("code = %v; want %v", code, tt.code)
}
if name != tt.want {
t.Errorf("ip = %v; want %v", name, tt.want)
}
})
}
}
func TestDelegate(t *testing.T) {
rc := tstest.NewResourceCheck()
defer rc.Assert(t)
dnsHandleFunc("test.site.", resolveToIP(testipv4, testipv6, "dns.test.site."))
dnsHandleFunc("nxdomain.site.", resolveToNXDOMAIN)
v4server, v4errch := serveDNS("127.0.0.1:0")
v6server, v6errch := serveDNS("[::1]:0")
defer func() {
if err := <-v4errch; err != nil {
t.Errorf("v4 server error: %v", err)
}
if err := <-v6errch; err != nil {
t.Errorf("v6 server error: %v", err)
}
}()
if v4server != nil {
defer v4server.Shutdown()
}
if v6server != nil {
defer v6server.Shutdown()
}
if v4server == nil || v6server == nil {
// There is an error in at least one of the channels
// and we cannot proceed; return to see it.
return
}
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: true})
r.SetMap(dnsMap)
r.SetUpstreams([]net.Addr{
v4server.PacketConn.LocalAddr(),
v6server.PacketConn.LocalAddr(),
})
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
tests := []struct {
title string
query []byte
response dnsResponse
}{
{
"ipv4",
dnspacket("test.site.", dns.TypeA),
dnsResponse{ip: testipv4, rcode: dns.RCodeSuccess},
},
{
"ipv6",
dnspacket("test.site.", dns.TypeAAAA),
dnsResponse{ip: testipv6, rcode: dns.RCodeSuccess},
},
{
"ns",
dnspacket("test.site.", dns.TypeNS),
dnsResponse{name: "dns.test.site.", rcode: dns.RCodeSuccess},
},
{
"nxdomain",
dnspacket("nxdomain.site.", dns.TypeA),
dnsResponse{rcode: dns.RCodeNameError},
},
}
for _, tt := range tests {
t.Run(tt.title, func(t *testing.T) {
payload, err := syncRespond(r, tt.query)
if err != nil {
t.Errorf("err = %v; want nil", err)
return
}
response, err := unpackResponse(payload)
if err != nil {
t.Errorf("extract: err = %v; want nil (in %x)", err, payload)
return
}
if response.rcode != tt.response.rcode {
t.Errorf("rcode = %v; want %v", response.rcode, tt.response.rcode)
}
if response.ip != tt.response.ip {
t.Errorf("ip = %v; want %v", response.ip, tt.response.ip)
}
if response.name != tt.response.name {
t.Errorf("name = %v; want %v", response.name, tt.response.name)
}
})
}
}
func TestDelegateCollision(t *testing.T) {
dnsHandleFunc("test.site.", resolveToIP(testipv4, testipv6, "dns.test.site."))
server, errch := serveDNS("127.0.0.1:0")
defer func() {
if err := <-errch; err != nil {
t.Errorf("server error: %v", err)
}
}()
if server == nil {
return
}
defer server.Shutdown()
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: true})
r.SetMap(dnsMap)
r.SetUpstreams([]net.Addr{server.PacketConn.LocalAddr()})
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
packets := []struct {
qname string
qtype dns.Type
addr netaddr.IPPort
}{
{"test.site.", dns.TypeA, netaddr.IPPort{IP: netaddr.IPv4(1, 1, 1, 1), Port: 1001}},
{"test.site.", dns.TypeAAAA, netaddr.IPPort{IP: netaddr.IPv4(1, 1, 1, 1), Port: 1002}},
}
// packets will have the same dns txid.
for _, p := range packets {
payload := dnspacket(p.qname, p.qtype)
req := Packet{Payload: payload, Addr: p.addr}
err := r.EnqueueRequest(req)
if err != nil {
t.Error(err)
}
}
// Despite the txid collision, the answer(s) should still match the query.
resp, err := r.NextResponse()
if err != nil {
t.Error(err)
}
var p dns.Parser
_, err = p.Start(resp.Payload)
if err != nil {
t.Error(err)
}
err = p.SkipAllQuestions()
if err != nil {
t.Error(err)
}
ans, err := p.AllAnswers()
if err != nil {
t.Error(err)
}
var wantType dns.Type
switch ans[0].Body.(type) {
case *dns.AResource:
wantType = dns.TypeA
case *dns.AAAAResource:
wantType = dns.TypeAAAA
default:
t.Errorf("unexpected answer type: %T", ans[0].Body)
}
for _, p := range packets {
if p.qtype == wantType && p.addr != resp.Addr {
t.Errorf("addr = %v; want %v", resp.Addr, p.addr)
}
}
}
func TestConcurrentSetMap(t *testing.T) {
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: false})
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
// This is purely to ensure that Resolve does not race with SetMap.
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
r.SetMap(dnsMap)
}()
go func() {
defer wg.Done()
r.Resolve("test1.ipn.dev", dns.TypeA)
}()
wg.Wait()
}
func TestConcurrentSetUpstreams(t *testing.T) {
dnsHandleFunc("test.site.", resolveToIP(testipv4, testipv6, "dns.test.site."))
server, errch := serveDNS("127.0.0.1:0")
defer func() {
if err := <-errch; err != nil {
t.Errorf("server error: %v", err)
}
}()
if server == nil {
return
}
defer server.Shutdown()
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: true})
r.SetMap(dnsMap)
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
packet := dnspacket("test.site.", dns.TypeA)
// This is purely to ensure that delegation does not race with SetUpstreams.
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
r.SetUpstreams([]net.Addr{server.PacketConn.LocalAddr()})
}()
go func() {
defer wg.Done()
syncRespond(r, packet)
}()
wg.Wait()
}
var allResponse = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x01, // one answer
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0xff, 0x00, 0x01, // type ALL, class IN
// Answer:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
0x00, 0x00, 0x02, 0x58, // TTL: 600
0x00, 0x04, // length: 4 bytes
0x01, 0x02, 0x03, 0x04, // A: 1.2.3.4
}
var ipv4Response = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x01, // one answer
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
// Answer:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
0x00, 0x00, 0x02, 0x58, // TTL: 600
0x00, 0x04, // length: 4 bytes
0x01, 0x02, 0x03, 0x04, // A: 1.2.3.4
}
var ipv6Response = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x01, // one answer
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x32, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x1c, 0x00, 0x01, // type AAAA, class IN
// Answer:
0x05, 0x74, 0x65, 0x73, 0x74, 0x32, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x1c, 0x00, 0x01, // type AAAA, class IN
0x00, 0x00, 0x02, 0x58, // TTL: 600
0x00, 0x10, // length: 16 bytes
// AAAA: 0001:0203:0405:0607:0809:0A0B:0C0D:0E0F
0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0xb, 0xc, 0xd, 0xe, 0xf,
}
var ipv4UppercaseResponse = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x01, // one answer
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x54, 0x45, 0x53, 0x54, 0x31, 0x03, 0x49, 0x50, 0x4e, 0x03, 0x44, 0x45, 0x56, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
// Answer:
0x05, 0x54, 0x45, 0x53, 0x54, 0x31, 0x03, 0x49, 0x50, 0x4e, 0x03, 0x44, 0x45, 0x56, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
0x00, 0x00, 0x02, 0x58, // TTL: 600
0x00, 0x04, // length: 4 bytes
0x01, 0x02, 0x03, 0x04, // A: 1.2.3.4
}
var ptrResponse = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x01, // one answer
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question: 4.3.2.1.in-addr.arpa
0x01, 0x34, 0x01, 0x33, 0x01, 0x32, 0x01, 0x31, 0x07,
0x69, 0x6e, 0x2d, 0x61, 0x64, 0x64, 0x72, 0x04, 0x61, 0x72, 0x70, 0x61, 0x00,
0x00, 0x0c, 0x00, 0x01, // type PTR, class IN
// Answer: 4.3.2.1.in-addr.arpa
0x01, 0x34, 0x01, 0x33, 0x01, 0x32, 0x01, 0x31, 0x07,
0x69, 0x6e, 0x2d, 0x61, 0x64, 0x64, 0x72, 0x04, 0x61, 0x72, 0x70, 0x61, 0x00,
0x00, 0x0c, 0x00, 0x01, // type PTR, class IN
0x00, 0x00, 0x02, 0x58, // TTL: 600
0x00, 0x0f, // length: 15 bytes
// PTR: test1.ipn.dev
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00,
}
var nxdomainResponse = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x03, // flags: response, authoritative, error: nxdomain
0x00, 0x01, // one question
0x00, 0x00, // no answers
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x33, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x01, 0x00, 0x01, // type A, class IN
}
var emptyResponse = []byte{
0x00, 0x00, // transaction id: 0
0x84, 0x00, // flags: response, authoritative, no error
0x00, 0x01, // one question
0x00, 0x00, // no answers
0x00, 0x00, 0x00, 0x00, // no authority or additional RRs
// Question:
0x05, 0x74, 0x65, 0x73, 0x74, 0x31, 0x03, 0x69, 0x70, 0x6e, 0x03, 0x64, 0x65, 0x76, 0x00, // name
0x00, 0x1c, 0x00, 0x01, // type AAAA, class IN
}
func TestFull(t *testing.T) {
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: false})
r.SetMap(dnsMap)
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
// One full packet and one error packet
tests := []struct {
name string
request []byte
response []byte
}{
{"all", dnspacket("test1.ipn.dev.", dns.TypeALL), allResponse},
{"ipv4", dnspacket("test1.ipn.dev.", dns.TypeA), ipv4Response},
{"ipv6", dnspacket("test2.ipn.dev.", dns.TypeAAAA), ipv6Response},
{"no-ipv6", dnspacket("test1.ipn.dev.", dns.TypeAAAA), emptyResponse},
{"upper", dnspacket("TEST1.IPN.DEV.", dns.TypeA), ipv4UppercaseResponse},
{"ptr", dnspacket("4.3.2.1.in-addr.arpa.", dns.TypePTR), ptrResponse},
{"nxdomain", dnspacket("test3.ipn.dev.", dns.TypeA), nxdomainResponse},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
response, err := syncRespond(r, tt.request)
if err != nil {
t.Errorf("err = %v; want nil", err)
}
if !bytes.Equal(response, tt.response) {
t.Errorf("response = %x; want %x", response, tt.response)
}
})
}
}
func TestAllocs(t *testing.T) {
r := NewResolver(ResolverConfig{Logf: t.Logf, Forward: false})
r.SetMap(dnsMap)
if err := r.Start(); err != nil {
t.Fatalf("start: %v", err)
}
defer r.Close()
// It is seemingly pointless to test allocs in the delegate path,
// as dialer.Dial -> Read -> Write alone comprise 12 allocs.
tests := []struct {
name string
query []byte
want int
}{
// Name lowercasing and response slice created by dns.NewBuilder.
{"forward", dnspacket("test1.ipn.dev.", dns.TypeA), 2},
// 3 extra allocs in rdnsNameToIPv4 and one in marshalPTRRecord (dns.NewName).
{"reverse", dnspacket("4.3.2.1.in-addr.arpa.", dns.TypePTR), 5},
}
for _, tt := range tests {
allocs := testing.AllocsPerRun(100, func() {
syncRespond(r, tt.query)
})
if int(allocs) > tt.want {
t.Errorf("%s: allocs = %v; want %v", tt.name, allocs, tt.want)
}
}
}
func TestTrimRDNSBonjourPrefix(t *testing.T) {
tests := []struct {
in string
want bool
}{
{"b._dns-sd._udp.0.10.20.172.in-addr.arpa.", true},
{"db._dns-sd._udp.0.10.20.172.in-addr.arpa.", true},
{"r._dns-sd._udp.0.10.20.172.in-addr.arpa.", true},
{"dr._dns-sd._udp.0.10.20.172.in-addr.arpa.", true},
{"lb._dns-sd._udp.0.10.20.172.in-addr.arpa.", true},
{"qq._dns-sd._udp.0.10.20.172.in-addr.arpa.", false},
{"0.10.20.172.in-addr.arpa.", false},
{"i-have-no-dot", false},
}
for _, test := range tests {
got := hasRDNSBonjourPrefix(test.in)
if got != test.want {
t.Errorf("trimRDNSBonjourPrefix(%q) = %v, want %v", test.in, got, test.want)
}
}
}
func BenchmarkFull(b *testing.B) {
dnsHandleFunc("test.site.", resolveToIP(testipv4, testipv6, "dns.test.site."))
server, errch := serveDNS("127.0.0.1:0")
defer func() {
if err := <-errch; err != nil {
b.Errorf("server error: %v", err)
}
}()
if server == nil {
return
}
defer server.Shutdown()
r := NewResolver(ResolverConfig{Logf: b.Logf, Forward: true})
r.SetMap(dnsMap)
r.SetUpstreams([]net.Addr{server.PacketConn.LocalAddr()})
if err := r.Start(); err != nil {
b.Fatalf("start: %v", err)
}
defer r.Close()
tests := []struct {
name string
request []byte
}{
{"forward", dnspacket("test1.ipn.dev.", dns.TypeA)},
{"reverse", dnspacket("4.3.2.1.in-addr.arpa.", dns.TypePTR)},
{"delegated", dnspacket("test.site.", dns.TypeA)},
}
for _, tt := range tests {
b.Run(tt.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
syncRespond(r, tt.request)
}
})
}
}