badguardhome/internal/dnsforward/dnsforward_test.go

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package dnsforward
import (
"crypto/ecdsa"
"crypto/rand"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"crypto/x509/pkix"
"encoding/pem"
"fmt"
"math/big"
"net"
"os"
"sync"
"testing"
"time"
"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
"github.com/AdguardTeam/AdGuardHome/internal/aghtest"
"github.com/AdguardTeam/AdGuardHome/internal/dhcpd"
"github.com/AdguardTeam/AdGuardHome/internal/filtering"
"github.com/AdguardTeam/dnsproxy/proxy"
"github.com/AdguardTeam/dnsproxy/upstream"
"github.com/AdguardTeam/golibs/errors"
"github.com/miekg/dns"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestMain(m *testing.M) {
aghtest.DiscardLogOutput(m)
}
const (
tlsServerName = "testdns.adguard.com"
testMessagesCount = 10
)
func startDeferStop(t *testing.T, s *Server) {
t.Helper()
err := s.Start()
require.NoErrorf(t, err, "failed to start server: %s", err)
t.Cleanup(func() {
serr := s.Stop()
require.NoErrorf(t, serr, "dns server failed to stop: %s", serr)
})
}
func createTestServer(
t *testing.T,
filterConf *filtering.Config,
forwardConf ServerConfig,
localUps upstream.Upstream,
) (s *Server) {
t.Helper()
rules := `||nxdomain.example.org
||null.example.org^
127.0.0.1 host.example.org
@@||whitelist.example.org^
||127.0.0.255`
filters := []filtering.Filter{{
ID: 0, Data: []byte(rules),
}}
f := filtering.New(filterConf, filters)
f.SetEnabled(true)
snd, err := aghnet.NewSubnetDetector()
require.NoError(t, err)
require.NotNil(t, snd)
s, err = NewServer(DNSCreateParams{
DHCPServer: &testDHCP{},
DNSFilter: f,
SubnetDetector: snd,
})
require.NoError(t, err)
s.conf = forwardConf
err = s.Prepare(nil)
require.NoError(t, err)
s.serverLock.Lock()
defer s.serverLock.Unlock()
if localUps != nil {
s.localResolvers.Config.UpstreamConfig.Upstreams = []upstream.Upstream{localUps}
s.conf.UsePrivateRDNS = true
}
return s
}
func createServerTLSConfig(t *testing.T) (*tls.Config, []byte, []byte) {
t.Helper()
privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
require.NoErrorf(t, err, "cannot generate RSA key: %s", err)
serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
require.NoErrorf(t, err, "failed to generate serial number: %s", err)
notBefore := time.Now()
notAfter := notBefore.Add(5 * 365 * time.Hour * 24)
template := x509.Certificate{
SerialNumber: serialNumber,
Subject: pkix.Name{
Organization: []string{"AdGuard Tests"},
},
NotBefore: notBefore,
NotAfter: notAfter,
KeyUsage: x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
BasicConstraintsValid: true,
IsCA: true,
}
template.DNSNames = append(template.DNSNames, tlsServerName)
derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, publicKey(privateKey), privateKey)
require.NoErrorf(t, err, "failed to create certificate: %s", err)
certPem := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
keyPem := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)})
cert, err := tls.X509KeyPair(certPem, keyPem)
require.NoErrorf(t, err, "failed to create certificate: %s", err)
return &tls.Config{
Certificates: []tls.Certificate{cert},
ServerName: tlsServerName,
MinVersion: tls.VersionTLS12,
}, certPem, keyPem
}
func createTestTLS(t *testing.T, tlsConf TLSConfig) (s *Server, certPem []byte) {
t.Helper()
var keyPem []byte
_, certPem, keyPem = createServerTLSConfig(t)
s = createTestServer(t, &filtering.Config{}, ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
}, nil)
tlsConf.CertificateChainData, tlsConf.PrivateKeyData = certPem, keyPem
s.conf.TLSConfig = tlsConf
err := s.Prepare(nil)
require.NoErrorf(t, err, "failed to prepare server: %s", err)
return s, certPem
}
func createGoogleATestMessage() *dns.Msg {
return createTestMessage("google-public-dns-a.google.com.")
}
func createTestMessage(host string) *dns.Msg {
return &dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
RecursionDesired: true,
},
Question: []dns.Question{{
Name: host,
Qtype: dns.TypeA,
Qclass: dns.ClassINET,
}},
}
}
func createTestMessageWithType(host string, qtype uint16) *dns.Msg {
req := createTestMessage(host)
req.Question[0].Qtype = qtype
return req
}
func assertGoogleAResponse(t *testing.T, reply *dns.Msg) {
assertResponse(t, reply, net.IP{8, 8, 8, 8})
}
func assertResponse(t *testing.T, reply *dns.Msg, ip net.IP) {
t.Helper()
require.Lenf(t, reply.Answer, 1, "dns server returned reply with wrong number of answers - %d", len(reply.Answer))
a, ok := reply.Answer[0].(*dns.A)
require.Truef(t, ok, "dns server returned wrong answer type instead of A: %v", reply.Answer[0])
assert.Truef(t, a.A.Equal(ip), "dns server returned wrong answer instead of %s: %s", ip, a.A)
}
// sendTestMessagesAsync sends messages in parallel to check for race issues.
//
//lint:ignore U1000 it's called from the function which is skipped for now.
func sendTestMessagesAsync(t *testing.T, conn *dns.Conn) {
t.Helper()
wg := &sync.WaitGroup{}
for i := 0; i < testMessagesCount; i++ {
msg := createGoogleATestMessage()
wg.Add(1)
go func() {
defer wg.Done()
err := conn.WriteMsg(msg)
require.NoErrorf(t, err, "cannot write message: %s", err)
res, err := conn.ReadMsg()
require.NoErrorf(t, err, "cannot read response to message: %s", err)
assertGoogleAResponse(t, res)
}()
}
wg.Wait()
}
func sendTestMessages(t *testing.T, conn *dns.Conn) {
t.Helper()
for i := 0; i < testMessagesCount; i++ {
req := createGoogleATestMessage()
err := conn.WriteMsg(req)
assert.NoErrorf(t, err, "cannot write message #%d: %s", i, err)
res, err := conn.ReadMsg()
assert.NoErrorf(t, err, "cannot read response to message #%d: %s", i, err)
assertGoogleAResponse(t, res)
}
}
func TestServer(t *testing.T) {
s := createTestServer(t, &filtering.Config{}, ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
}, nil)
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
IPv4: map[string][]net.IP{
"google-public-dns-a.google.com.": {{8, 8, 8, 8}},
},
},
}
startDeferStop(t, s)
testCases := []struct {
name string
proto string
}{{
name: "message_over_udp",
proto: proxy.ProtoUDP,
}, {
name: "message_over_tcp",
proto: proxy.ProtoTCP,
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
addr := s.dnsProxy.Addr(tc.proto)
client := dns.Client{Net: tc.proto}
reply, _, err := client.Exchange(createGoogleATestMessage(), addr.String())
require.NoErrorf(t, err, "сouldn't talk to server %s: %s", addr, err)
assertGoogleAResponse(t, reply)
})
}
}
func TestServer_timeout(t *testing.T) {
const timeout time.Duration = time.Second
t.Run("custom", func(t *testing.T) {
srvConf := &ServerConfig{
UpstreamTimeout: timeout,
}
s, err := NewServer(DNSCreateParams{})
require.NoError(t, err)
err = s.Prepare(srvConf)
require.NoError(t, err)
assert.Equal(t, timeout, s.conf.UpstreamTimeout)
})
t.Run("default", func(t *testing.T) {
s, err := NewServer(DNSCreateParams{})
require.NoError(t, err)
err = s.Prepare(nil)
require.NoError(t, err)
assert.Equal(t, DefaultTimeout, s.conf.UpstreamTimeout)
})
}
func TestServerWithProtectionDisabled(t *testing.T) {
s := createTestServer(t, &filtering.Config{}, ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
}, nil)
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
IPv4: map[string][]net.IP{
"google-public-dns-a.google.com.": {{8, 8, 8, 8}},
},
},
}
startDeferStop(t, s)
// Message over UDP.
req := createGoogleATestMessage()
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
client := dns.Client{Net: proxy.ProtoUDP}
reply, _, err := client.Exchange(req, addr.String())
require.NoErrorf(t, err, "сouldn't talk to server %s: %s", addr, err)
assertGoogleAResponse(t, reply)
}
func TestDoTServer(t *testing.T) {
s, certPem := createTestTLS(t, TLSConfig{
TLSListenAddrs: []*net.TCPAddr{{}},
})
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
IPv4: map[string][]net.IP{
"google-public-dns-a.google.com.": {{8, 8, 8, 8}},
},
},
}
startDeferStop(t, s)
// Add our self-signed generated config to roots.
roots := x509.NewCertPool()
roots.AppendCertsFromPEM(certPem)
tlsConfig := &tls.Config{
ServerName: tlsServerName,
RootCAs: roots,
MinVersion: tls.VersionTLS12,
}
// Create a DNS-over-TLS client connection.
addr := s.dnsProxy.Addr(proxy.ProtoTLS)
conn, err := dns.DialWithTLS("tcp-tls", addr.String(), tlsConfig)
require.NoErrorf(t, err, "cannot connect to the proxy: %s", err)
sendTestMessages(t, conn)
}
func TestDoQServer(t *testing.T) {
s, _ := createTestTLS(t, TLSConfig{
QUICListenAddrs: []*net.UDPAddr{{IP: net.IP{127, 0, 0, 1}}},
})
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
IPv4: map[string][]net.IP{
"google-public-dns-a.google.com.": {{8, 8, 8, 8}},
},
},
}
startDeferStop(t, s)
// Create a DNS-over-QUIC upstream.
addr := s.dnsProxy.Addr(proxy.ProtoQUIC)
opts := upstream.Options{InsecureSkipVerify: true}
u, err := upstream.AddressToUpstream(fmt.Sprintf("%s://%s", proxy.ProtoQUIC, addr), opts)
require.NoError(t, err)
// Send the test message.
req := createGoogleATestMessage()
res, err := u.Exchange(req)
require.NoError(t, err)
assertGoogleAResponse(t, res)
}
func TestServerRace(t *testing.T) {
t.Skip("TODO(e.burkov): inspect the golibs/cache package for locks")
filterConf := &filtering.Config{
SafeBrowsingEnabled: true,
SafeBrowsingCacheSize: 1000,
SafeSearchEnabled: true,
SafeSearchCacheSize: 1000,
ParentalCacheSize: 1000,
CacheTime: 30,
}
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
UpstreamDNS: []string{"8.8.8.8:53", "8.8.4.4:53"},
},
ConfigModified: func() {},
}
s := createTestServer(t, filterConf, forwardConf, nil)
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
IPv4: map[string][]net.IP{
"google-public-dns-a.google.com.": {{8, 8, 8, 8}},
},
},
}
startDeferStop(t, s)
// Message over UDP.
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
conn, err := dns.Dial(proxy.ProtoUDP, addr.String())
require.NoErrorf(t, err, "cannot connect to the proxy: %s", err)
sendTestMessagesAsync(t, conn)
}
func TestSafeSearch(t *testing.T) {
resolver := &aghtest.TestResolver{}
filterConf := &filtering.Config{
SafeSearchEnabled: true,
SafeSearchCacheSize: 1000,
CacheTime: 30,
CustomResolver: resolver,
}
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
},
}
s := createTestServer(t, filterConf, forwardConf, nil)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP).String()
client := dns.Client{Net: proxy.ProtoUDP}
yandexIP := net.IP{213, 180, 193, 56}
googleIP, _ := resolver.HostToIPs("forcesafesearch.google.com")
testCases := []struct {
host string
want net.IP
}{{
host: "yandex.com.",
want: yandexIP,
}, {
host: "yandex.by.",
want: yandexIP,
}, {
host: "yandex.kz.",
want: yandexIP,
}, {
host: "yandex.ru.",
want: yandexIP,
}, {
host: "www.google.com.",
want: googleIP,
}, {
host: "www.google.com.af.",
want: googleIP,
}, {
host: "www.google.be.",
want: googleIP,
}, {
host: "www.google.by.",
want: googleIP,
}}
for _, tc := range testCases {
t.Run(tc.host, func(t *testing.T) {
req := createTestMessage(tc.host)
reply, _, err := client.Exchange(req, addr)
require.NoErrorf(t, err, "couldn't talk to server %s: %s", addr, err)
assertResponse(t, reply, tc.want)
})
}
}
func TestInvalidRequest(t *testing.T) {
s := createTestServer(t, &filtering.Config{}, ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
}, nil)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP).String()
req := dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
RecursionDesired: true,
},
}
// Send a DNS request without question.
_, _, err := (&dns.Client{
Net: proxy.ProtoUDP,
Timeout: 500 * time.Millisecond,
}).Exchange(&req, addr)
assert.NoErrorf(t, err, "got a response to an invalid query")
}
func TestBlockedRequest(t *testing.T) {
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
},
}
s := createTestServer(t, &filtering.Config{}, forwardConf, nil)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// Default blocking.
req := createTestMessage("nxdomain.example.org.")
reply, err := dns.Exchange(req, addr.String())
require.NoErrorf(t, err, "couldn't talk to server %s: %s", addr, err)
assert.Equal(t, dns.RcodeSuccess, reply.Rcode)
require.Len(t, reply.Answer, 1)
assert.True(t, reply.Answer[0].(*dns.A).A.IsUnspecified())
}
func TestServerCustomClientUpstream(t *testing.T) {
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
},
}
s := createTestServer(t, &filtering.Config{}, forwardConf, nil)
s.conf.GetCustomUpstreamByClient = func(_ string) (conf *proxy.UpstreamConfig, err error) {
ups := &aghtest.TestUpstream{
IPv4: map[string][]net.IP{
"host.": {{192, 168, 0, 1}},
},
}
return &proxy.UpstreamConfig{
Upstreams: []upstream.Upstream{ups},
}, nil
}
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// Send test request.
req := createTestMessage("host.")
reply, err := dns.Exchange(req, addr.String())
require.NoError(t, err)
assert.Equal(t, dns.RcodeSuccess, reply.Rcode)
require.NotEmpty(t, reply.Answer)
require.Len(t, reply.Answer, 1)
assert.Equal(t, net.IP{192, 168, 0, 1}, reply.Answer[0].(*dns.A).A)
}
// testCNAMEs is a map of names and CNAMEs necessary for the TestUpstream work.
var testCNAMEs = map[string]string{
"badhost.": "null.example.org.",
"whitelist.example.org.": "null.example.org.",
}
// testIPv4 is a map of names and IPv4s necessary for the TestUpstream work.
var testIPv4 = map[string][]net.IP{
"null.example.org.": {{1, 2, 3, 4}},
"example.org.": {{127, 0, 0, 255}},
}
func TestBlockCNAMEProtectionEnabled(t *testing.T) {
s := createTestServer(t, &filtering.Config{}, ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
}, nil)
testUpstm := &aghtest.TestUpstream{
CName: testCNAMEs,
IPv4: testIPv4,
IPv6: nil,
}
s.conf.ProtectionEnabled = false
s.dnsProxy.UpstreamConfig = &proxy.UpstreamConfig{
Upstreams: []upstream.Upstream{testUpstm},
}
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// 'badhost' has a canonical name 'null.example.org' which should be
// blocked by filters, but protection is disabled so it is not.
req := createTestMessage("badhost.")
reply, err := dns.Exchange(req, addr.String())
require.NoError(t, err)
assert.Equal(t, dns.RcodeSuccess, reply.Rcode)
}
func TestBlockCNAME(t *testing.T) {
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
},
}
s := createTestServer(t, &filtering.Config{}, forwardConf, nil)
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
CName: testCNAMEs,
IPv4: testIPv4,
},
}
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP).String()
testCases := []struct {
host string
want bool
}{{
host: "badhost.",
// 'badhost' has a canonical name 'null.example.org' which is
// blocked by filters: response is blocked.
want: true,
}, {
host: "whitelist.example.org.",
// 'whitelist.example.org' has a canonical name
// 'null.example.org' which is blocked by filters
// but 'whitelist.example.org' is in a whitelist:
// response isn't blocked.
want: false,
}, {
host: "example.org.",
// 'example.org' has a canonical name 'cname1' with IP
// 127.0.0.255 which is blocked by filters: response is blocked.
want: true,
}}
for _, tc := range testCases {
t.Run("block_cname_"+tc.host, func(t *testing.T) {
req := createTestMessage(tc.host)
reply, err := dns.Exchange(req, addr)
require.NoError(t, err)
assert.Equal(t, dns.RcodeSuccess, reply.Rcode)
if tc.want {
require.Len(t, reply.Answer, 1)
a, ok := reply.Answer[0].(*dns.A)
require.True(t, ok)
assert.True(t, a.A.IsUnspecified())
}
})
}
}
func TestClientRulesForCNAMEMatching(t *testing.T) {
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
FilterHandler: func(_ net.IP, _ string, settings *filtering.Settings) {
settings.FilteringEnabled = false
},
},
}
s := createTestServer(t, &filtering.Config{}, forwardConf, nil)
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
CName: testCNAMEs,
IPv4: testIPv4,
},
}
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// 'badhost' has a canonical name 'null.example.org' which is blocked by
// filters: response is blocked.
req := dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
},
Question: []dns.Question{{
Name: "badhost.",
Qtype: dns.TypeA,
Qclass: dns.ClassINET,
}},
}
// However, in our case it should not be blocked as filtering is
// disabled on the client level.
reply, err := dns.Exchange(&req, addr.String())
require.NoError(t, err)
assert.Equal(t, dns.RcodeSuccess, reply.Rcode)
}
func TestNullBlockedRequest(t *testing.T) {
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
BlockingMode: "null_ip",
},
}
s := createTestServer(t, &filtering.Config{}, forwardConf, nil)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// Nil filter blocking.
req := dns.Msg{
MsgHdr: dns.MsgHdr{
Id: dns.Id(),
RecursionDesired: true,
},
Question: []dns.Question{{
Name: "null.example.org.",
Qtype: dns.TypeA,
Qclass: dns.ClassINET,
}},
}
reply, err := dns.Exchange(&req, addr.String())
require.NoErrorf(t, err, "couldn't talk to server %s: %s", addr, err)
require.Lenf(t, reply.Answer, 1, "dns server %s returned reply with wrong number of answers - %d", addr, len(reply.Answer))
a, ok := reply.Answer[0].(*dns.A)
require.Truef(t, ok, "dns server %s returned wrong answer type instead of A: %v", addr, reply.Answer[0])
assert.Truef(t, a.A.IsUnspecified(), "dns server %s returned wrong answer instead of 0.0.0.0: %v", addr, a.A)
}
func TestBlockedCustomIP(t *testing.T) {
rules := "||nxdomain.example.org^\n||null.example.org^\n127.0.0.1 host.example.org\n@@||whitelist.example.org^\n||127.0.0.255\n"
filters := []filtering.Filter{{
ID: 0,
Data: []byte(rules),
}}
snd, err := aghnet.NewSubnetDetector()
require.NoError(t, err)
require.NotNil(t, snd)
f := filtering.New(&filtering.Config{}, filters)
var s *Server
s, err = NewServer(DNSCreateParams{
DHCPServer: &testDHCP{},
DNSFilter: f,
SubnetDetector: snd,
})
require.NoError(t, err)
conf := &ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
BlockingMode: "custom_ip",
BlockingIPv4: nil,
UpstreamDNS: []string{"8.8.8.8:53", "8.8.4.4:53"},
},
}
// Invalid BlockingIPv4.
err = s.Prepare(conf)
assert.Error(t, err)
conf.BlockingIPv4 = net.IP{0, 0, 0, 1}
conf.BlockingIPv6 = net.ParseIP("::1")
err = s.Prepare(conf)
require.NoError(t, err)
f.SetEnabled(true)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
req := createTestMessageWithType("null.example.org.", dns.TypeA)
reply, err := dns.Exchange(req, addr.String())
require.NoError(t, err)
require.Len(t, reply.Answer, 1)
a, ok := reply.Answer[0].(*dns.A)
require.True(t, ok)
assert.True(t, net.IP{0, 0, 0, 1}.Equal(a.A))
req = createTestMessageWithType("null.example.org.", dns.TypeAAAA)
reply, err = dns.Exchange(req, addr.String())
require.NoError(t, err)
require.Len(t, reply.Answer, 1)
a6, ok := reply.Answer[0].(*dns.AAAA)
require.True(t, ok)
assert.Equal(t, "::1", a6.AAAA.String())
}
func TestBlockedByHosts(t *testing.T) {
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
},
}
s := createTestServer(t, &filtering.Config{}, forwardConf, nil)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// Hosts blocking.
req := createTestMessage("host.example.org.")
reply, err := dns.Exchange(req, addr.String())
require.NoErrorf(t, err, "couldn't talk to server %s: %s", addr, err)
require.Lenf(t, reply.Answer, 1, "dns server %s returned reply with wrong number of answers - %d", addr, len(reply.Answer))
a, ok := reply.Answer[0].(*dns.A)
require.Truef(t, ok, "dns server %s returned wrong answer type instead of A: %v", addr, reply.Answer[0])
assert.Equalf(t, net.IP{127, 0, 0, 1}, a.A, "dns server %s returned wrong answer instead of 8.8.8.8: %v", addr, a.A)
}
func TestBlockedBySafeBrowsing(t *testing.T) {
const hostname = "wmconvirus.narod.ru"
sbUps := &aghtest.TestBlockUpstream{
Hostname: hostname,
Block: true,
}
ans4, _ := (&aghtest.TestResolver{}).HostToIPs(hostname)
filterConf := &filtering.Config{
SafeBrowsingEnabled: true,
}
forwardConf := ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
SafeBrowsingBlockHost: ans4.String(),
ProtectionEnabled: true,
},
}
s := createTestServer(t, filterConf, forwardConf, nil)
s.dnsFilter.SetSafeBrowsingUpstream(sbUps)
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
// SafeBrowsing blocking.
req := createTestMessage(hostname + ".")
reply, err := dns.Exchange(req, addr.String())
require.NoErrorf(t, err, "couldn't talk to server %s: %s", addr, err)
require.Lenf(t, reply.Answer, 1, "dns server %s returned reply with wrong number of answers - %d", addr, len(reply.Answer))
a, ok := reply.Answer[0].(*dns.A)
require.Truef(t, ok, "dns server %s returned wrong answer type instead of A: %v", addr, reply.Answer[0])
assert.Equal(t, ans4, a.A, "dns server %s returned wrong answer: %v", addr, a.A)
}
func TestRewrite(t *testing.T) {
c := &filtering.Config{
Rewrites: []filtering.RewriteEntry{{
Domain: "test.com",
Answer: "1.2.3.4",
Type: dns.TypeA,
}, {
Domain: "alias.test.com",
Answer: "test.com",
Type: dns.TypeCNAME,
}, {
Domain: "my.alias.example.org",
Answer: "example.org",
Type: dns.TypeCNAME,
}},
}
f := filtering.New(c, nil)
snd, err := aghnet.NewSubnetDetector()
require.NoError(t, err)
require.NotNil(t, snd)
var s *Server
s, err = NewServer(DNSCreateParams{
DHCPServer: &testDHCP{},
DNSFilter: f,
SubnetDetector: snd,
})
require.NoError(t, err)
assert.NoError(t, s.Prepare(&ServerConfig{
UDPListenAddrs: []*net.UDPAddr{{}},
TCPListenAddrs: []*net.TCPAddr{{}},
FilteringConfig: FilteringConfig{
ProtectionEnabled: true,
UpstreamDNS: []string{"8.8.8.8:53"},
},
}))
s.conf.UpstreamConfig.Upstreams = []upstream.Upstream{
&aghtest.TestUpstream{
CName: map[string]string{
"example.org": "somename",
},
IPv4: map[string][]net.IP{
"example.org.": {{4, 3, 2, 1}},
},
},
}
startDeferStop(t, s)
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
req := createTestMessageWithType("test.com.", dns.TypeA)
reply, err := dns.Exchange(req, addr.String())
require.NoError(t, err)
require.Len(t, reply.Answer, 1)
a, ok := reply.Answer[0].(*dns.A)
require.True(t, ok)
assert.True(t, net.IP{1, 2, 3, 4}.Equal(a.A))
req = createTestMessageWithType("test.com.", dns.TypeAAAA)
reply, err = dns.Exchange(req, addr.String())
require.NoError(t, err)
assert.Empty(t, reply.Answer)
req = createTestMessageWithType("alias.test.com.", dns.TypeA)
reply, err = dns.Exchange(req, addr.String())
require.NoError(t, err)
require.Len(t, reply.Answer, 2)
assert.Equal(t, "test.com.", reply.Answer[0].(*dns.CNAME).Target)
assert.True(t, net.IP{1, 2, 3, 4}.Equal(reply.Answer[1].(*dns.A).A))
req = createTestMessageWithType("my.alias.example.org.", dns.TypeA)
reply, err = dns.Exchange(req, addr.String())
require.NoError(t, err)
// The original question is restored.
require.Len(t, reply.Question, 1)
assert.Equal(t, "my.alias.example.org.", reply.Question[0].Name)
require.Len(t, reply.Answer, 2)
assert.Equal(t, "example.org.", reply.Answer[0].(*dns.CNAME).Target)
assert.Equal(t, dns.TypeA, reply.Answer[1].Header().Rrtype)
}
func publicKey(priv interface{}) interface{} {
switch k := priv.(type) {
case *rsa.PrivateKey:
return &k.PublicKey
case *ecdsa.PrivateKey:
return &k.PublicKey
default:
return nil
}
}
type testDHCP struct{}
func (d *testDHCP) Enabled() (ok bool) { return true }
func (d *testDHCP) Leases(flags int) []dhcpd.Lease {
l := dhcpd.Lease{
IP: net.IP{192, 168, 12, 34},
HWAddr: net.HardwareAddr{0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA},
Hostname: "myhost",
}
return []dhcpd.Lease{l}
}
func (d *testDHCP) SetOnLeaseChanged(onLeaseChanged dhcpd.OnLeaseChangedT) {}
func TestPTRResponseFromDHCPLeases(t *testing.T) {
snd, err := aghnet.NewSubnetDetector()
require.NoError(t, err)
require.NotNil(t, snd)
var s *Server
s, err = NewServer(DNSCreateParams{
DNSFilter: filtering.New(&filtering.Config{}, nil),
DHCPServer: &testDHCP{},
SubnetDetector: snd,
})
require.NoError(t, err)
s.conf.UDPListenAddrs = []*net.UDPAddr{{}}
s.conf.TCPListenAddrs = []*net.TCPAddr{{}}
s.conf.UpstreamDNS = []string{"127.0.0.1:53"}
s.conf.FilteringConfig.ProtectionEnabled = true
err = s.Prepare(nil)
require.NoError(t, err)
err = s.Start()
require.NoError(t, err)
t.Cleanup(func() {
s.Close()
})
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
req := createTestMessageWithType("34.12.168.192.in-addr.arpa.", dns.TypePTR)
resp, err := dns.Exchange(req, addr.String())
require.NoError(t, err)
require.Len(t, resp.Answer, 1)
assert.Equal(t, dns.TypePTR, resp.Answer[0].Header().Rrtype)
assert.Equal(t, "34.12.168.192.in-addr.arpa.", resp.Answer[0].Header().Name)
ptr, ok := resp.Answer[0].(*dns.PTR)
require.True(t, ok)
assert.Equal(t, "myhost.", ptr.Ptr)
}
func TestPTRResponseFromHosts(t *testing.T) {
c := filtering.Config{
EtcHosts: &aghnet.EtcHostsContainer{},
}
// Prepare test hosts file.
hf, err := os.CreateTemp("", "")
require.NoError(t, err)
t.Cleanup(func() {
assert.NoError(t, hf.Close())
assert.NoError(t, os.Remove(hf.Name()))
})
_, _ = hf.WriteString(" 127.0.0.1 host # comment \n")
_, _ = hf.WriteString(" ::1 localhost#comment \n")
c.EtcHosts.Init(hf.Name())
t.Cleanup(c.EtcHosts.Close)
var snd *aghnet.SubnetDetector
snd, err = aghnet.NewSubnetDetector()
require.NoError(t, err)
require.NotNil(t, snd)
var s *Server
s, err = NewServer(DNSCreateParams{
DHCPServer: &testDHCP{},
DNSFilter: filtering.New(&c, nil),
SubnetDetector: snd,
})
require.NoError(t, err)
s.conf.UDPListenAddrs = []*net.UDPAddr{{}}
s.conf.TCPListenAddrs = []*net.TCPAddr{{}}
s.conf.UpstreamDNS = []string{"127.0.0.1:53"}
s.conf.FilteringConfig.ProtectionEnabled = true
err = s.Prepare(nil)
require.NoError(t, err)
err = s.Start()
require.NoError(t, err)
t.Cleanup(func() {
s.Close()
})
addr := s.dnsProxy.Addr(proxy.ProtoUDP)
req := createTestMessageWithType("1.0.0.127.in-addr.arpa.", dns.TypePTR)
resp, err := dns.Exchange(req, addr.String())
require.NoError(t, err)
require.Len(t, resp.Answer, 1)
assert.Equal(t, dns.TypePTR, resp.Answer[0].Header().Rrtype)
assert.Equal(t, "1.0.0.127.in-addr.arpa.", resp.Answer[0].Header().Name)
ptr, ok := resp.Answer[0].(*dns.PTR)
require.True(t, ok)
assert.Equal(t, "host.", ptr.Ptr)
}
func TestNewServer(t *testing.T) {
testCases := []struct {
name string
in DNSCreateParams
wantErrMsg string
}{{
name: "success",
in: DNSCreateParams{},
wantErrMsg: "",
}, {
name: "success_local_tld",
in: DNSCreateParams{
LocalDomain: "mynet",
},
wantErrMsg: "",
}, {
name: "success_local_domain",
in: DNSCreateParams{
LocalDomain: "my.local.net",
},
wantErrMsg: "",
}, {
name: "bad_local_domain",
in: DNSCreateParams{
LocalDomain: "!!!",
},
wantErrMsg: `local domain: validating domain name "!!!": ` +
`invalid domain name label at index 0: ` +
`validating label "!!!": invalid char '!' at index 0`,
}}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
_, err := NewServer(tc.in)
if tc.wantErrMsg == "" {
assert.NoError(t, err)
} else {
require.Error(t, err)
assert.Equal(t, tc.wantErrMsg, err.Error())
}
})
}
}
func TestServer_Exchange(t *testing.T) {
extUpstream := &aghtest.TestUpstream{
Reverse: map[string][]string{
"1.1.1.1.in-addr.arpa.": {"one.one.one.one"},
},
}
locUpstream := &aghtest.TestUpstream{
Reverse: map[string][]string{
"1.1.168.192.in-addr.arpa.": {"local.domain"},
"2.1.168.192.in-addr.arpa.": {},
},
}
upstreamErr := errors.Error("upstream error")
errUpstream := &aghtest.TestErrUpstream{
Err: upstreamErr,
}
nonPtrUpstream := &aghtest.TestBlockUpstream{
Hostname: "some-host",
Block: true,
}
srv := NewCustomServer(&proxy.Proxy{
Config: proxy.Config{
UpstreamConfig: &proxy.UpstreamConfig{
Upstreams: []upstream.Upstream{extUpstream},
},
},
})
srv.conf.ResolveClients = true
srv.conf.UsePrivateRDNS = true
var err error
srv.subnetDetector, err = aghnet.NewSubnetDetector()
require.NoError(t, err)
localIP := net.IP{192, 168, 1, 1}
testCases := []struct {
name string
want string
wantErr error
locUpstream upstream.Upstream
req net.IP
}{{
name: "external_good",
want: "one.one.one.one",
wantErr: nil,
locUpstream: nil,
req: net.IP{1, 1, 1, 1},
}, {
name: "local_good",
want: "local.domain",
wantErr: nil,
locUpstream: locUpstream,
req: localIP,
}, {
name: "upstream_error",
want: "",
wantErr: upstreamErr,
locUpstream: errUpstream,
req: localIP,
}, {
name: "empty_answer_error",
want: "",
wantErr: rDNSEmptyAnswerErr,
locUpstream: locUpstream,
req: net.IP{192, 168, 1, 2},
}, {
name: "not_ptr_error",
want: "",
wantErr: rDNSNotPTRErr,
locUpstream: nonPtrUpstream,
req: localIP,
}}
for _, tc := range testCases {
pcfg := proxy.Config{
UpstreamConfig: &proxy.UpstreamConfig{
Upstreams: []upstream.Upstream{tc.locUpstream},
},
}
srv.localResolvers = &proxy.Proxy{
Config: pcfg,
}
t.Run(tc.name, func(t *testing.T) {
host, eerr := srv.Exchange(tc.req)
require.ErrorIs(t, eerr, tc.wantErr)
assert.Equal(t, tc.want, host)
})
}
t.Run("resolving_disabled", func(t *testing.T) {
srv.conf.UsePrivateRDNS = false
host, eerr := srv.Exchange(localIP)
require.NoError(t, eerr)
assert.Empty(t, host)
})
}