package dnsforward import ( "crypto/ecdsa" "crypto/rand" "crypto/rsa" "crypto/tls" "crypto/x509" "crypto/x509/pkix" "encoding/pem" "math/big" "net" "sync" "testing" "time" "github.com/AdguardTeam/AdGuardHome/dnsfilter" "github.com/AdguardTeam/dnsproxy/proxy" "github.com/AdguardTeam/dnsproxy/upstream" "github.com/miekg/dns" "github.com/stretchr/testify/assert" ) const ( tlsServerName = "testdns.adguard.com" testMessagesCount = 10 ) func TestServer(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } // message over UDP req := createGoogleATestMessage() addr := s.dnsProxy.Addr(proxy.ProtoUDP) client := dns.Client{Net: "udp"} reply, _, err := client.Exchange(req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } assertGoogleAResponse(t, reply) // message over TCP req = createGoogleATestMessage() addr = s.dnsProxy.Addr("tcp") client = dns.Client{Net: "tcp"} reply, _, err = client.Exchange(req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } assertGoogleAResponse(t, reply) err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestServerWithProtectionDisabled(t *testing.T) { s := createTestServer(t) s.conf.ProtectionEnabled = false err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } // message over UDP req := createGoogleATestMessage() addr := s.dnsProxy.Addr(proxy.ProtoUDP) client := dns.Client{Net: "udp"} reply, _, err := client.Exchange(req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } assertGoogleAResponse(t, reply) err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestDotServer(t *testing.T) { // Prepare the proxy server _, certPem, keyPem := createServerTLSConfig(t) s := createTestServer(t) s.conf.TLSConfig = TLSConfig{ TLSListenAddr: &net.TCPAddr{Port: 0}, CertificateChainData: certPem, PrivateKeyData: keyPem, } // Starting the server err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } // 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) if err != nil { t.Fatalf("cannot connect to the proxy: %s", err) } sendTestMessages(t, conn) // Stop the proxy err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestServerRace(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } // message over UDP addr := s.dnsProxy.Addr(proxy.ProtoUDP) conn, err := dns.Dial("udp", addr.String()) if err != nil { t.Fatalf("cannot connect to the proxy: %s", err) } sendTestMessagesAsync(t, conn) // Stop the proxy err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestSafeSearch(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } // Test safe search for yandex. We already know safe search ip addr := s.dnsProxy.Addr(proxy.ProtoUDP) client := dns.Client{Net: "udp"} yandexDomains := []string{"yandex.com.", "yandex.by.", "yandex.kz.", "yandex.ru.", "yandex.com."} for _, host := range yandexDomains { exchangeAndAssertResponse(t, &client, addr, host, "213.180.193.56") } // Let's lookup for google safesearch ip ips, err := net.LookupIP("forcesafesearch.google.com") if err != nil { t.Fatalf("Failed to lookup for forcesafesearch.google.com: %s", err) } ip := ips[0] for _, i := range ips { if i.To4() != nil { ip = i break } } // Test safe search for google. googleDomains := []string{"www.google.com.", "www.google.com.af.", "www.google.be.", "www.google.by."} for _, host := range googleDomains { exchangeAndAssertResponse(t, &client, addr, host, ip.String()) } err = s.Stop() if err != nil { t.Fatalf("Can not stopd server cause: %s", err) } } func TestInvalidRequest(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } // server is running, send a message addr := s.dnsProxy.Addr(proxy.ProtoUDP) req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true // send a DNS request without question client := dns.Client{Net: "udp", Timeout: 500 * time.Millisecond} _, _, err = client.Exchange(&req, addr.String()) if err != nil { t.Fatalf("got a response to an invalid query") } err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestBlockedRequest(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } addr := s.dnsProxy.Addr(proxy.ProtoUDP) // // NXDomain blocking // req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {Name: "nxdomain.example.org.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err := dns.Exchange(&req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } if reply.Rcode != dns.RcodeNameError { t.Fatalf("Wrong response: %s", reply.String()) } err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } // testUpstream is a mock of real upstream. // specify fields with necessary values to simulate real upstream behaviour type testUpstream struct { cn map[string]string // Map of [name]canonical_name ipv4 map[string][]net.IP // Map of [name]IPv4 ipv6 map[string][]net.IP // Map of [name]IPv6 } func (u *testUpstream) Exchange(m *dns.Msg) (*dns.Msg, error) { resp := dns.Msg{} resp.SetReply(m) hasARecord := false hasAAAARecord := false reqType := m.Question[0].Qtype name := m.Question[0].Name // Let's check if we have any CNAME for given name if cname, ok := u.cn[name]; ok { cn := dns.CNAME{} cn.Hdr.Name = name cn.Hdr.Rrtype = dns.TypeCNAME cn.Target = cname resp.Answer = append(resp.Answer, &cn) } // Let's check if we can add some A records to the answer if ipv4addr, ok := u.ipv4[name]; ok && reqType == dns.TypeA { hasARecord = true for _, ipv4 := range ipv4addr { respA := dns.A{} respA.Hdr.Rrtype = dns.TypeA respA.Hdr.Name = name respA.A = ipv4 resp.Answer = append(resp.Answer, &respA) } } // Let's check if we can add some AAAA records to the answer if u.ipv6 != nil { if ipv6addr, ok := u.ipv6[name]; ok && reqType == dns.TypeAAAA { hasAAAARecord = true for _, ipv6 := range ipv6addr { respAAAA := dns.A{} respAAAA.Hdr.Rrtype = dns.TypeAAAA respAAAA.Hdr.Name = name respAAAA.A = ipv6 resp.Answer = append(resp.Answer, &respAAAA) } } } if len(resp.Answer) == 0 { if hasARecord || hasAAAARecord { // Set No Error RCode if there are some records for given Qname but we didn't apply them resp.SetRcode(m, dns.RcodeSuccess) } else { // Set NXDomain RCode otherwise resp.SetRcode(m, dns.RcodeNameError) } } return &resp, nil } func (u *testUpstream) Address() string { return "test" } func (s *Server) startWithUpstream(u upstream.Upstream) error { s.Lock() defer s.Unlock() err := s.prepare(nil) if err != nil { return err } s.dnsProxy.Upstreams = []upstream.Upstream{u} return s.dnsProxy.Start() } // testCNAMEs is a simple 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 simple 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 TestBlockCNAME(t *testing.T) { s := createTestServer(t) testUpstm := &testUpstream{testCNAMEs, testIPv4, nil} err := s.startWithUpstream(testUpstm) assert.True(t, err == nil) 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{} req.Id = dns.Id() req.Question = []dns.Question{ {Name: "badhost.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err := dns.Exchange(&req, addr.String()) assert.True(t, err == nil) assert.True(t, reply.Rcode == dns.RcodeNameError) // '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 req = dns.Msg{} req.Id = dns.Id() req.Question = []dns.Question{ {Name: "whitelist.example.org.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err = dns.Exchange(&req, addr.String()) assert.True(t, err == nil) assert.True(t, reply.Rcode == dns.RcodeSuccess) // 'example.org' has a canonical name 'cname1' with IP 127.0.0.255 which is blocked by filters: // response is blocked req = dns.Msg{} req.Id = dns.Id() req.Question = []dns.Question{ {Name: "example.org.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err = dns.Exchange(&req, addr.String()) assert.True(t, err == nil) assert.True(t, reply.Rcode == dns.RcodeNameError) _ = s.Stop() } func TestNullBlockedRequest(t *testing.T) { s := createTestServer(t) s.conf.FilteringConfig.BlockingMode = "null_ip" err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } addr := s.dnsProxy.Addr(proxy.ProtoUDP) // // Null filter blocking // req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {Name: "null.example.org.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err := dns.Exchange(&req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } if len(reply.Answer) != 1 { t.Fatalf("DNS server %s returned reply with wrong number of answers - %d", addr, len(reply.Answer)) } if a, ok := reply.Answer[0].(*dns.A); ok { if !net.IPv4zero.Equal(a.A) { t.Fatalf("DNS server %s returned wrong answer instead of 0.0.0.0: %v", addr, a.A) } } else { t.Fatalf("DNS server %s returned wrong answer type instead of A: %v", addr, reply.Answer[0]) } err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestBlockedByHosts(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } addr := s.dnsProxy.Addr(proxy.ProtoUDP) // // Hosts blocking // req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {Name: "host.example.org.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err := dns.Exchange(&req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } if len(reply.Answer) != 1 { t.Fatalf("DNS server %s returned reply with wrong number of answers - %d", addr, len(reply.Answer)) } if a, ok := reply.Answer[0].(*dns.A); ok { if !net.IPv4(127, 0, 0, 1).Equal(a.A) { t.Fatalf("DNS server %s returned wrong answer instead of 8.8.8.8: %v", addr, a.A) } } else { t.Fatalf("DNS server %s returned wrong answer type instead of A: %v", addr, reply.Answer[0]) } err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func TestBlockedBySafeBrowsing(t *testing.T) { s := createTestServer(t) err := s.Start(nil) if err != nil { t.Fatalf("Failed to start server: %s", err) } addr := s.dnsProxy.Addr(proxy.ProtoUDP) // // Safebrowsing blocking // req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {Name: "wmconvirus.narod.ru.", Qtype: dns.TypeA, Qclass: dns.ClassINET}, } reply, err := dns.Exchange(&req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } if len(reply.Answer) != 1 { t.Fatalf("DNS server %s returned reply with wrong number of answers - %d", addr, len(reply.Answer)) } if a, ok := reply.Answer[0].(*dns.A); ok { addrs, lookupErr := net.LookupHost(safeBrowsingBlockHost) if lookupErr != nil { t.Fatalf("cannot resolve %s due to %s", safeBrowsingBlockHost, lookupErr) } found := false for _, blockAddr := range addrs { if blockAddr == a.A.String() { found = true } } if !found { t.Fatalf("DNS server %s returned wrong answer: %v", addr, a.A) } } else { t.Fatalf("DNS server %s returned wrong answer type instead of A: %v", addr, reply.Answer[0]) } err = s.Stop() if err != nil { t.Fatalf("DNS server failed to stop: %s", err) } } func createTestServer(t *testing.T) *Server { 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 := map[int]string{} filters[0] = rules c := dnsfilter.Config{} c.SafeBrowsingEnabled = true c.SafeBrowsingCacheSize = 1000 c.SafeSearchEnabled = true c.SafeSearchCacheSize = 1000 c.ParentalCacheSize = 1000 c.CacheTime = 30 f := dnsfilter.New(&c, filters) s := NewServer(f, nil, nil) s.conf.UDPListenAddr = &net.UDPAddr{Port: 0} s.conf.TCPListenAddr = &net.TCPAddr{Port: 0} s.conf.UpstreamDNS = []string{"8.8.8.8:53", "8.8.4.4:53"} s.conf.FilteringConfig.ProtectionEnabled = true return s } func createServerTLSConfig(t *testing.T) (*tls.Config, []byte, []byte) { privateKey, err := rsa.GenerateKey(rand.Reader, 2048) if err != nil { t.Fatalf("cannot generate RSA key: %s", err) } serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128) serialNumber, err := rand.Int(rand.Reader, serialNumberLimit) if err != nil { t.Fatalf("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) if err != nil { t.Fatalf("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) if err != nil { t.Fatalf("failed to create certificate: %s", err) } return &tls.Config{Certificates: []tls.Certificate{cert}, ServerName: tlsServerName, MinVersion: tls.VersionTLS12}, certPem, keyPem } func sendTestMessageAsync(t *testing.T, conn *dns.Conn, g *sync.WaitGroup) { defer func() { g.Done() }() req := createGoogleATestMessage() err := conn.WriteMsg(req) if err != nil { t.Fatalf("cannot write message: %s", err) } res, err := conn.ReadMsg() if err != nil { t.Fatalf("cannot read response to message: %s", err) } assertGoogleAResponse(t, res) } // sendTestMessagesAsync sends messages in parallel // so that we could find race issues func sendTestMessagesAsync(t *testing.T, conn *dns.Conn) { g := &sync.WaitGroup{} g.Add(testMessagesCount) for i := 0; i < testMessagesCount; i++ { go sendTestMessageAsync(t, conn, g) } g.Wait() } func sendTestMessages(t *testing.T, conn *dns.Conn) { for i := 0; i < 10; i++ { req := createGoogleATestMessage() err := conn.WriteMsg(req) if err != nil { t.Fatalf("cannot write message #%d: %s", i, err) } res, err := conn.ReadMsg() if err != nil { t.Fatalf("cannot read response to message #%d: %s", i, err) } assertGoogleAResponse(t, res) } } func exchangeAndAssertResponse(t *testing.T, client *dns.Client, addr net.Addr, host, ip string) { req := createTestMessage(host) reply, _, err := client.Exchange(req, addr.String()) if err != nil { t.Fatalf("Couldn't talk to server %s: %s", addr, err) } assertResponse(t, reply, ip) } func createGoogleATestMessage() *dns.Msg { return createTestMessage("google-public-dns-a.google.com.") } func createTestMessage(host string) *dns.Msg { req := dns.Msg{} req.Id = dns.Id() req.RecursionDesired = true req.Question = []dns.Question{ {Name: host, Qtype: dns.TypeA, Qclass: dns.ClassINET}, } return &req } func assertGoogleAResponse(t *testing.T, reply *dns.Msg) { assertResponse(t, reply, "8.8.8.8") } func assertResponse(t *testing.T, reply *dns.Msg, ip string) { if len(reply.Answer) != 1 { t.Fatalf("DNS server returned reply with wrong number of answers - %d", len(reply.Answer)) } if a, ok := reply.Answer[0].(*dns.A); ok { if !net.ParseIP(ip).Equal(a.A) { t.Fatalf("DNS server returned wrong answer instead of %s: %v", ip, a.A) } } else { t.Fatalf("DNS server returned wrong answer type instead of A: %v", reply.Answer[0]) } } func publicKey(priv interface{}) interface{} { switch k := priv.(type) { case *rsa.PrivateKey: return &k.PublicKey case *ecdsa.PrivateKey: return &k.PublicKey default: return nil } } func TestIsBlockedIPAllowed(t *testing.T) { a := &accessCtx{} assert.True(t, a.Init([]string{"1.1.1.1", "2.2.0.0/16"}, nil, nil) == nil) assert.True(t, !a.IsBlockedIP("1.1.1.1")) assert.True(t, a.IsBlockedIP("1.1.1.2")) assert.True(t, !a.IsBlockedIP("2.2.1.1")) assert.True(t, a.IsBlockedIP("2.3.1.1")) } func TestIsBlockedIPDisallowed(t *testing.T) { a := &accessCtx{} assert.True(t, a.Init(nil, []string{"1.1.1.1", "2.2.0.0/16"}, nil) == nil) assert.True(t, a.IsBlockedIP("1.1.1.1")) assert.True(t, !a.IsBlockedIP("1.1.1.2")) assert.True(t, a.IsBlockedIP("2.2.1.1")) assert.True(t, !a.IsBlockedIP("2.3.1.1")) } func TestIsBlockedIPBlockedDomain(t *testing.T) { a := &accessCtx{} assert.True(t, a.Init(nil, nil, []string{"host1", "host2"}) == nil) assert.True(t, a.IsBlockedDomain("host1")) assert.True(t, a.IsBlockedDomain("host2")) assert.True(t, !a.IsBlockedDomain("host3")) } func TestValidateUpstream(t *testing.T) { invalidUpstreams := []string{"1.2.3.4.5", "123.3.7m", "htttps://google.com/dns-query", "[/host.com]tls://dns.adguard.com", "[host.ru]#", } validDefaultUpstreams := []string{"1.1.1.1", "tls://1.1.1.1", "https://dns.adguard.com/dns-query", "sdns://AQMAAAAAAAAAFDE3Ni4xMDMuMTMwLjEzMDo1NDQzINErR_JS3PLCu_iZEIbq95zkSV2LFsigxDIuUso_OQhzIjIuZG5zY3J5cHQuZGVmYXVsdC5uczEuYWRndWFyZC5jb20", } validUpstreams := []string{"[/host.com/]1.1.1.1", "[//]tls://1.1.1.1", "[/www.host.com/]#", "[/host.com/google.com/]8.8.8.8", "[/host/]sdns://AQMAAAAAAAAAFDE3Ni4xMDMuMTMwLjEzMDo1NDQzINErR_JS3PLCu_iZEIbq95zkSV2LFsigxDIuUso_OQhzIjIuZG5zY3J5cHQuZGVmYXVsdC5uczEuYWRndWFyZC5jb20", } for _, u := range invalidUpstreams { _, err := validateUpstream(u) if err == nil { t.Fatalf("upstream %s is invalid but it pass through validation", u) } } for _, u := range validDefaultUpstreams { defaultUpstream, err := validateUpstream(u) if err != nil { t.Fatalf("upstream %s is valid but it doen't pass through validation cause: %s", u, err) } if !defaultUpstream { t.Fatalf("upstream %s is default one!", u) } } for _, u := range validUpstreams { defaultUpstream, err := validateUpstream(u) if err != nil { t.Fatalf("upstream %s is valid but it doen't pass through validation cause: %s", u, err) } if defaultUpstream { t.Fatalf("upstream %s is default one!", u) } } } func TestValidateUpstreamsSet(t *testing.T) { // Set of valid upstreams. There is no default upstream specified upstreamsSet := []string{"[/host.com/]1.1.1.1", "[//]tls://1.1.1.1", "[/www.host.com/]#", "[/host.com/google.com/]8.8.8.8", "[/host/]sdns://AQMAAAAAAAAAFDE3Ni4xMDMuMTMwLjEzMDo1NDQzINErR_JS3PLCu_iZEIbq95zkSV2LFsigxDIuUso_OQhzIjIuZG5zY3J5cHQuZGVmYXVsdC5uczEuYWRndWFyZC5jb20", } err := ValidateUpstreams(upstreamsSet) if err == nil { t.Fatalf("there is no default upstream") } // Let's add default upstream upstreamsSet = append(upstreamsSet, "8.8.8.8") err = ValidateUpstreams(upstreamsSet) if err != nil { t.Fatalf("upstreams set is valid, but doesn't pass through validation cause: %s", err) } // Let's add invalid upstream upstreamsSet = append(upstreamsSet, "dhcp://fake.dns") err = ValidateUpstreams(upstreamsSet) if err == nil { t.Fatalf("there is an invalid upstream in set, but it pass through validation") } }