Add DisableIPv4 & DisableIPv6

client.go

@@ -28,6 +28,8 @@ type HTTPClientSettings struct {
 	FullOnDisk            bool
 	VerifyCerts           bool
 	RandomLocalIP         bool
+	DisableIPv4           bool
+	DisableIPv6           bool
 }
 
 type CustomHTTPClient struct {
@@ -147,7 +149,7 @@ func NewWARCWritingHTTPClient(HTTPClientSettings HTTPClientSettings) (httpClient
 	httpClient.TLSHandshakeTimeout = HTTPClientSettings.TLSHandshakeTimeout
 
 	// Configure custom dialer / transport
-	customDialer, err := newCustomDialer(httpClient, HTTPClientSettings.Proxy, HTTPClientSettings.DialTimeout)
+	customDialer, err := newCustomDialer(httpClient, HTTPClientSettings.Proxy, HTTPClientSettings.DialTimeout, HTTPClientSettings.DisableIPv4, HTTPClientSettings.DisableIPv6)
 	if err != nil {
 		return nil, err
 	}

client_test.go

@@ -1,6 +1,7 @@
 package warc
 
 import (
+	"context"
 	"io"
 	"net"
 	"net/http"
@@ -1267,6 +1268,148 @@ func TestHTTPClientWithZStandardDictionary(t *testing.T) {
 	}
 }
 
+func setupIPv4Server(t *testing.T) (string, func()) {
+	listener, err := net.Listen("tcp4", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("Failed to set up IPv4 server: %v", err)
+	}
+
+	server := &http.Server{
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Write([]byte("IPv4 Server"))
+		}),
+	}
+
+	go server.Serve(listener)
+
+	return "http://" + listener.Addr().String(), func() {
+		server.Shutdown(context.Background())
+	}
+}
+
+func setupIPv6Server(t *testing.T) (string, func()) {
+	listener, err := net.Listen("tcp6", "[::1]:0")
+	if err != nil {
+		t.Fatalf("Failed to set up IPv6 server: %v", err)
+	}
+
+	server := &http.Server{
+		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Write([]byte("IPv6 Server"))
+		}),
+	}
+
+	go server.Serve(listener)
+
+	return "http://" + listener.Addr().String(), func() {
+		server.Shutdown(context.Background())
+	}
+}
+
+func TestHTTPClientWithIPv4Disabled(t *testing.T) {
+	defer goleak.VerifyNone(t)
+
+	ipv4URL, closeIPv4 := setupIPv4Server(t)
+	defer closeIPv4()
+
+	ipv6URL, closeIPv6 := setupIPv6Server(t)
+	defer closeIPv6()
+
+	rotatorSettings := NewRotatorSettings()
+	rotatorSettings.OutputDirectory, _ = os.MkdirTemp("", "warc-tests-")
+	defer os.RemoveAll(rotatorSettings.OutputDirectory)
+	rotatorSettings.Prefix = "TESTIPv6Only"
+
+	httpClient, err := NewWARCWritingHTTPClient(HTTPClientSettings{
+		RotatorSettings: rotatorSettings,
+		DisableIPv4:     true,
+	})
+	if err != nil {
+		t.Fatalf("Unable to init WARC writing HTTP client: %s", err)
+	}
+
+	// Try IPv4 - should fail
+	_, err = httpClient.Get(ipv4URL)
+	if err == nil {
+		t.Fatalf("Expected error when connecting to IPv4 server, but got none")
+	}
+
+	// Try IPv6 - should succeed
+	resp, err := httpClient.Get(ipv6URL)
+	if err != nil {
+		t.Fatalf("Failed to connect to IPv6 server: %v", err)
+	}
+	defer resp.Body.Close()
+
+	body, _ := io.ReadAll(resp.Body)
+	if string(body) != "IPv6 Server" {
+		t.Fatalf("Unexpected response from IPv6 server: %s", string(body))
+	}
+
+	httpClient.Close()
+
+	files, err := filepath.Glob(rotatorSettings.OutputDirectory + "/*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, path := range files {
+		testFileSingleHashCheck(t, path, "sha1:RTK62UJNR5UCIPX2J64LMV7J4JJ6EXCJ", []string{"147"}, 1)
+	}
+}
+
+func TestHTTPClientWithIPv6Disabled(t *testing.T) {
+	defer goleak.VerifyNone(t)
+
+	ipv4URL, closeIPv4 := setupIPv4Server(t)
+	defer closeIPv4()
+
+	ipv6URL, closeIPv6 := setupIPv6Server(t)
+	defer closeIPv6()
+
+	rotatorSettings := NewRotatorSettings()
+	rotatorSettings.OutputDirectory, _ = os.MkdirTemp("", "warc-tests-")
+	defer os.RemoveAll(rotatorSettings.OutputDirectory)
+	rotatorSettings.Prefix = "TESTIPv4Only"
+
+	httpClient, err := NewWARCWritingHTTPClient(HTTPClientSettings{
+		RotatorSettings: rotatorSettings,
+		DisableIPv6:     true,
+	})
+	if err != nil {
+		t.Fatalf("Unable to init WARC writing HTTP client: %s", err)
+	}
+
+	// Try IPv6 - should fail
+	_, err = httpClient.Get(ipv6URL)
+	if err == nil {
+		t.Fatalf("Expected error when connecting to IPv6 server, but got none")
+	}
+
+	// Try IPv4 - should succeed
+	resp, err := httpClient.Get(ipv4URL)
+	if err != nil {
+		t.Fatalf("Failed to connect to IPv4 server: %v", err)
+	}
+	defer resp.Body.Close()
+
+	body, _ := io.ReadAll(resp.Body)
+	if string(body) != "IPv4 Server" {
+		t.Fatalf("Unexpected response from IPv4 server: %s", string(body))
+	}
+
+	httpClient.Close()
+
+	files, err := filepath.Glob(rotatorSettings.OutputDirectory + "/*")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, path := range files {
+		testFileSingleHashCheck(t, path, "sha1:JZIRQ2YRCQ55F6SSNPTXHKMDSKJV6QFM", []string{"147"}, 1)
+	}
+}
+
 func BenchmarkConcurrentUnder2MB(b *testing.B) {
 	var (
 		rotatorSettings = NewRotatorSettings()

dialer.go

@@ -24,14 +24,18 @@ import (
 type customDialer struct {
 	proxyDialer proxy.Dialer
 	client      *CustomHTTPClient
+	disableIPv4 bool
+	disableIPv6 bool
 	net.Dialer
 }
 
-func newCustomDialer(httpClient *CustomHTTPClient, proxyURL string, DialTimeout time.Duration) (d *customDialer, err error) {
+func newCustomDialer(httpClient *CustomHTTPClient, proxyURL string, DialTimeout time.Duration, disableIPv4, disableIPv6 bool) (d *customDialer, err error) {
 	d = new(customDialer)
 
 	d.Timeout = DialTimeout
 	d.client = httpClient
+	d.disableIPv4 = disableIPv4
+	d.disableIPv6 = disableIPv6
 
 	if proxyURL != "" {
 		u, err := url.Parse(proxyURL)
@@ -87,59 +91,65 @@ func (d *customDialer) wrapConnection(c net.Conn, scheme string) net.Conn {
 }
 
 func (d *customDialer) CustomDial(network, address string) (conn net.Conn, err error) {
+	// Determine the network based on IPv4/IPv6 settings
+	network = d.getNetworkType(network)
+	if network == "" {
+		return nil, errors.New("no supported network type available")
+	}
+
 	if d.proxyDialer != nil {
 		conn, err = d.proxyDialer.Dial(network, address)
-		if err != nil {
-			return nil, err
-		}
 	} else {
 		if d.client.randomLocalIP {
 			localAddr := getLocalAddr(network, address)
 			if localAddr != nil {
-				if network == "tcp" {
+				if network == "tcp" || network == "tcp4" || network == "tcp6" {
 					d.LocalAddr = localAddr.(*net.TCPAddr)
-				} else if network == "udp" {
+				} else if network == "udp" || network == "udp4" || network == "udp6" {
 					d.LocalAddr = localAddr.(*net.UDPAddr)
 				}
 			}
 		}
 
 		conn, err = d.Dial(network, address)
-		if err != nil {
-			return nil, err
-		}
+	}
+
+	if err != nil {
+		return nil, err
 	}
 
 	return d.wrapConnection(conn, "http"), nil
 }
 
 func (d *customDialer) CustomDialTLS(network, address string) (net.Conn, error) {
-	var (
-		plainConn net.Conn
-		err       error
-	)
+	// Determine the network based on IPv4/IPv6 settings
+	network = d.getNetworkType(network)
+	if network == "" {
+		return nil, errors.New("no supported network type available")
+	}
+
+	var plainConn net.Conn
+	var err error
 
 	if d.proxyDialer != nil {
 		plainConn, err = d.proxyDialer.Dial(network, address)
-		if err != nil {
-			return nil, err
-		}
 	} else {
 		if d.client.randomLocalIP {
 			localAddr := getLocalAddr(network, address)
 			if localAddr != nil {
-				if network == "tcp" {
+				if network == "tcp" || network == "tcp4" || network == "tcp6" {
 					d.LocalAddr = localAddr.(*net.TCPAddr)
-				} else if network == "udp" {
+				} else if network == "udp" || network == "udp4" || network == "udp6" {
 					d.LocalAddr = localAddr.(*net.UDPAddr)
 				}
 			}
 		}
 
 		plainConn, err = d.Dial(network, address)
-		if err != nil {
-			return nil, err
-		}
+	}
+
+	if err != nil {
+		return nil, err
 	}
 
 	cfg := new(tls.Config)
@@ -171,6 +181,31 @@ func (d *customDialer) CustomDialTLS(network, address string) (net.Conn, error)
 	return d.wrapConnection(tlsConn, "https"), nil
 }
 
+func (d *customDialer) getNetworkType(network string) string {
+	switch network {
+	case "tcp", "udp":
+		if d.disableIPv4 && !d.disableIPv6 {
+			return network + "6"
+		}
+		if !d.disableIPv4 && d.disableIPv6 {
+			return network + "4"
+		}
+		return network // Both enabled or both disabled, use default
+	case "tcp4", "udp4":
+		if d.disableIPv4 {
+			return ""
+		}
+		return network
+	case "tcp6", "udp6":
+		if d.disableIPv6 {
+			return ""
+		}
+		return network
+	default:
+		return "" // Unsupported network type
+	}
+}
+
 func (d *customDialer) writeWARCFromConnection(reqPipe, respPipe *io.PipeReader, scheme string, conn net.Conn) {
 	defer d.client.WaitGroup.Done()