TUN-8236: Add write timeout to quic and tcp connections

## Summary
To prevent bad eyeballs and severs to be able to exhaust the quic
control flows we are adding the possibility of having a timeout
for a write operation to be acknowledged. This will prevent hanging
connections from exhausting the quic control flows, creating a DDoS.

ingress/constants_test.go

@@ -0,0 +1,7 @@
+package ingress
+
+import "github.com/cloudflare/cloudflared/logger"
+
+var (
+	TestLogger = logger.Create(nil)
+)

ingress/origin_connection.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 	"net"
+	"time"
 
 	"github.com/rs/zerolog"
 
@@ -31,15 +32,32 @@ func DefaultStreamHandler(originConn io.ReadWriter, remoteConn net.Conn, log *ze
 
 // tcpConnection is an OriginConnection that directly streams to raw TCP.
 type tcpConnection struct {
-	conn net.Conn
+	net.Conn
+	writeTimeout time.Duration
+	logger       *zerolog.Logger
 }
 
-func (tc *tcpConnection) Stream(ctx context.Context, tunnelConn io.ReadWriter, log *zerolog.Logger) {
-	stream.Pipe(tunnelConn, tc.conn, log)
+func (tc *tcpConnection) Stream(_ context.Context, tunnelConn io.ReadWriter, _ *zerolog.Logger) {
+	stream.Pipe(tunnelConn, tc, tc.logger)
+}
+
+func (tc *tcpConnection) Write(b []byte) (int, error) {
+	if tc.writeTimeout > 0 {
+		if err := tc.Conn.SetWriteDeadline(time.Now().Add(tc.writeTimeout)); err != nil {
+			tc.logger.Err(err).Msg("Error setting write deadline for TCP connection")
+		}
+	}
+
+	nBytes, err := tc.Conn.Write(b)
+	if err != nil {
+		tc.logger.Err(err).Msg("Error writing to the TCP connection")
+	}
+
+	return nBytes, err
 }
 
 func (tc *tcpConnection) Close() {
-	tc.conn.Close()
+	tc.Conn.Close()
 }
 
 // tcpOverWSConnection is an OriginConnection that streams to TCP over WS.

ingress/origin_connection_test.go

@@ -19,7 +19,6 @@ import (
 	"golang.org/x/net/proxy"
 	"golang.org/x/sync/errgroup"
 
-	"github.com/cloudflare/cloudflared/logger"
 	"github.com/cloudflare/cloudflared/socks"
 	"github.com/cloudflare/cloudflared/stream"
 	"github.com/cloudflare/cloudflared/websocket"
@@ -31,7 +30,6 @@ const (
 )
 
 var (
-	testLogger   = logger.Create(nil)
 	testMessage  = []byte("TestStreamOriginConnection")
 	testResponse = []byte(fmt.Sprintf("echo-%s", testMessage))
 )
@@ -39,7 +37,8 @@ var (
 func TestStreamTCPConnection(t *testing.T) {
 	cfdConn, originConn := net.Pipe()
 	tcpConn := tcpConnection{
-		conn: cfdConn,
+		Conn:         cfdConn,
+		writeTimeout: 30 * time.Second,
 	}
 
 	eyeballConn, edgeConn := net.Pipe()
@@ -66,7 +65,7 @@ func TestStreamTCPConnection(t *testing.T) {
 		return nil
 	})
 
-	tcpConn.Stream(ctx, edgeConn, testLogger)
+	tcpConn.Stream(ctx, edgeConn, TestLogger)
 	require.NoError(t, errGroup.Wait())
 }
 
@@ -93,7 +92,7 @@ func TestDefaultStreamWSOverTCPConnection(t *testing.T) {
 		return nil
 	})
 
-	tcpOverWSConn.Stream(ctx, edgeConn, testLogger)
+	tcpOverWSConn.Stream(ctx, edgeConn, TestLogger)
 	require.NoError(t, errGroup.Wait())
 }
 
@@ -147,7 +146,7 @@ func TestSocksStreamWSOverTCPConnection(t *testing.T) {
 
 		errGroup, ctx := errgroup.WithContext(ctx)
 		errGroup.Go(func() error {
-			tcpOverWSConn.Stream(ctx, edgeConn, testLogger)
+			tcpOverWSConn.Stream(ctx, edgeConn, TestLogger)
 			return nil
 		})
 
@@ -159,7 +158,7 @@ func TestSocksStreamWSOverTCPConnection(t *testing.T) {
 			require.NoError(t, err)
 			defer wsForwarderInConn.Close()
 
-			stream.Pipe(wsForwarderInConn, &wsEyeball{wsForwarderOutConn}, testLogger)
+			stream.Pipe(wsForwarderInConn, &wsEyeball{wsForwarderOutConn}, TestLogger)
 			return nil
 		})
 
@@ -209,7 +208,7 @@ func TestWsConnReturnsBeforeStreamReturns(t *testing.T) {
 			originConn.Close()
 		}()
 		ctx := context.WithValue(r.Context(), websocket.PingPeriodContextKey, time.Microsecond)
-		tcpOverWSConn.Stream(ctx, eyeballConn, testLogger)
+		tcpOverWSConn.Stream(ctx, eyeballConn, TestLogger)
 	})
 	server := httptest.NewServer(handler)
 	defer server.Close()

ingress/origin_proxy.go

@@ -4,6 +4,8 @@ import (
 	"context"
 	"fmt"
 	"net/http"
+
+	"github.com/rs/zerolog"
 )
 
 // HTTPOriginProxy can be implemented by origin services that want to proxy http requests.
@@ -14,7 +16,7 @@ type HTTPOriginProxy interface {
 
 // StreamBasedOriginProxy can be implemented by origin services that want to proxy ws/TCP.
 type StreamBasedOriginProxy interface {
-	EstablishConnection(ctx context.Context, dest string) (OriginConnection, error)
+	EstablishConnection(ctx context.Context, dest string, log *zerolog.Logger) (OriginConnection, error)
 }
 
 // HTTPLocalProxy can be implemented by cloudflared services that want to handle incoming http requests.
@@ -62,19 +64,21 @@ func (o *statusCode) RoundTrip(_ *http.Request) (*http.Response, error) {
 	return resp, nil
 }
 
-func (o *rawTCPService) EstablishConnection(ctx context.Context, dest string) (OriginConnection, error) {
+func (o *rawTCPService) EstablishConnection(ctx context.Context, dest string, logger *zerolog.Logger) (OriginConnection, error) {
 	conn, err := o.dialer.DialContext(ctx, "tcp", dest)
 	if err != nil {
 		return nil, err
 	}
 
 	originConn := &tcpConnection{
-		conn: conn,
+		Conn:         conn,
+		writeTimeout: o.writeTimeout,
+		logger:       logger,
 	}
 	return originConn, nil
 }
 
-func (o *tcpOverWSService) EstablishConnection(ctx context.Context, dest string) (OriginConnection, error) {
+func (o *tcpOverWSService) EstablishConnection(ctx context.Context, dest string, _ *zerolog.Logger) (OriginConnection, error) {
 	var err error
 	if !o.isBastion {
 		dest = o.dest
@@ -92,6 +96,6 @@ func (o *tcpOverWSService) EstablishConnection(ctx context.Context, dest string)
 
 }
 
-func (o *socksProxyOverWSService) EstablishConnection(_ctx context.Context, _dest string) (OriginConnection, error) {
+func (o *socksProxyOverWSService) EstablishConnection(_ context.Context, _ string, _ *zerolog.Logger) (OriginConnection, error) {
 	return o.conn, nil
 }

ingress/origin_proxy_test.go

@@ -36,7 +36,7 @@ func TestRawTCPServiceEstablishConnection(t *testing.T) {
 	require.NoError(t, err)
 
 	// Origin not listening for new connection, should return an error
-	_, err = rawTCPService.EstablishConnection(context.Background(), req.URL.String())
+	_, err = rawTCPService.EstablishConnection(context.Background(), req.URL.String(), TestLogger)
 	require.Error(t, err)
 }
 
@@ -87,7 +87,7 @@ func TestTCPOverWSServiceEstablishConnection(t *testing.T) {
 		t.Run(test.testCase, func(t *testing.T) {
 			if test.expectErr {
 				bastionHost, _ := carrier.ResolveBastionDest(test.req)
-				_, err := test.service.EstablishConnection(context.Background(), bastionHost)
+				_, err := test.service.EstablishConnection(context.Background(), bastionHost, TestLogger)
 				assert.Error(t, err)
 			}
 		})
@@ -99,7 +99,7 @@ func TestTCPOverWSServiceEstablishConnection(t *testing.T) {
 	for _, service := range []*tcpOverWSService{newTCPOverWSService(originURL), newBastionService()} {
 		// Origin not listening for new connection, should return an error
 		bastionHost, _ := carrier.ResolveBastionDest(bastionReq)
-		_, err := service.EstablishConnection(context.Background(), bastionHost)
+		_, err := service.EstablishConnection(context.Background(), bastionHost, TestLogger)
 		assert.Error(t, err)
 	}
 }
@@ -132,7 +132,7 @@ func TestHTTPServiceHostHeaderOverride(t *testing.T) {
 		url: originURL,
 	}
 	shutdownC := make(chan struct{})
-	require.NoError(t, httpService.start(testLogger, shutdownC, cfg))
+	require.NoError(t, httpService.start(TestLogger, shutdownC, cfg))
 
 	req, err := http.NewRequest(http.MethodGet, originURL.String(), nil)
 	require.NoError(t, err)
@@ -167,7 +167,7 @@ func TestHTTPServiceUsesIngressRuleScheme(t *testing.T) {
 		url: originURL,
 	}
 	shutdownC := make(chan struct{})
-	require.NoError(t, httpService.start(testLogger, shutdownC, cfg))
+	require.NoError(t, httpService.start(TestLogger, shutdownC, cfg))
 
 	// Tunnel uses scheme defined in the service field of the ingress rule, independent of the X-Forwarded-Proto header
 	protos := []string{"https", "http", "dne"}

ingress/origin_service.go

@@ -94,15 +94,17 @@ func (o httpService) MarshalJSON() ([]byte, error) {
 // rawTCPService dials TCP to the destination specified by the client
 // It's used by warp routing
 type rawTCPService struct {
-	name   string
-	dialer net.Dialer
+	name         string
+	dialer       net.Dialer
+	writeTimeout time.Duration
+	logger       *zerolog.Logger
 }
 
 func (o *rawTCPService) String() string {
 	return o.name
 }
 
-func (o *rawTCPService) start(log *zerolog.Logger, _ <-chan struct{}, cfg OriginRequestConfig) error {
+func (o *rawTCPService) start(_ *zerolog.Logger, _ <-chan struct{}, _ OriginRequestConfig) error {
 	return nil
 }
 
@@ -285,13 +287,14 @@ type WarpRoutingService struct {
 	Proxy StreamBasedOriginProxy
 }
 
-func NewWarpRoutingService(config WarpRoutingConfig) *WarpRoutingService {
+func NewWarpRoutingService(config WarpRoutingConfig, writeTimeout time.Duration) *WarpRoutingService {
 	svc := &rawTCPService{
 		name: ServiceWarpRouting,
 		dialer: net.Dialer{
 			Timeout:   config.ConnectTimeout.Duration,
 			KeepAlive: config.TCPKeepAlive.Duration,
 		},
+		writeTimeout: writeTimeout,
 	}
 
 	return &WarpRoutingService{Proxy: svc}