fix: adding timeout to the typha server TLS handshake (#7909)

typha/fv-tests/server_test.go

@@ -20,6 +20,7 @@ import (
 	"encoding/gob"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"os"
 	"path/filepath"
@@ -1611,6 +1612,19 @@ var _ = Describe("with server requiring TLS", func() {
 		}
 	}
 
+	testTcpHalfOpen := func() {
+		deadline := time.Now().Add(9 * time.Second)
+		serverAddr := fmt.Sprintf("127.0.0.1:%d", server.Port())
+		tcpConn, err := net.Dial("tcp", serverAddr)
+		Expect(err).NotTo(HaveOccurred())
+		err = tcpConn.SetDeadline(time.Now().Add(30 * time.Second))
+		Expect(err).NotTo(HaveOccurred())
+		received := make([]byte, 1024)
+		_, err = tcpConn.Read(received)
+		Expect(err).Should(Equal(io.EOF))
+		Expect(time.Now().Unix()).Should(BeNumerically(">=", deadline.Unix()))
+	}
+
 	Describe("and CN or URI SAN", func() {
 		BeforeEach(func() {
 			requiredClientCN = clientCN
@@ -1686,4 +1700,14 @@ var _ = Describe("with server requiring TLS", func() {
 
 		It("TLS connection with good CN and URI should fail", testTLSGoodCNURI(false))
 	})
+
+	Describe("handshake", func() {
+		BeforeEach(func() {
+			requiredClientCN = clientCN
+			requiredClientURISAN = clientURISAN
+			serverCertName = "server"
+		})
+
+		It("should timeout after 10 seconds for TCP half open connections", testTcpHalfOpen)
+	})
 })

typha/pkg/config/config_params.go

@@ -120,6 +120,7 @@ type Config struct {
 	ServerMinBatchingAgeThresholdSecs    time.Duration `config:"seconds;0.01"`
 	ServerPingIntervalSecs               time.Duration `config:"seconds;10"`
 	ServerPongTimeoutSecs                time.Duration `config:"seconds;60"`
+	ServerHandshakeTimeoutSecs           time.Duration `config:"seconds;10"`
 	ServerPort                           int           `config:"port;0"`
 
 	// Server-side TLS config for Typha's communication with Felix.  If any of these are

typha/pkg/daemon/daemon.go

@@ -394,6 +394,7 @@ func (t *TyphaDaemon) CreateServer() {
 			NewClientFallBehindGracePeriod: t.ConfigParams.ServerNewClientFallBehindGracePeriod,
 			PingInterval:                   t.ConfigParams.ServerPingIntervalSecs,
 			PongTimeout:                    t.ConfigParams.ServerPongTimeoutSecs,
+			HandshakeTimeout:               t.ConfigParams.ServerHandshakeTimeoutSecs,
 			DropInterval:                   t.ConfigParams.ConnectionDropIntervalSecs,
 			ShutdownTimeout:                t.ConfigParams.ShutdownTimeoutSecs,
 			ShutdownMaxDropInterval:        t.ConfigParams.ShutdownConnectionDropIntervalMaxSecs,

typha/pkg/syncserver/sync_server.go

@@ -101,6 +101,7 @@ const (
 	defaultBatchingAgeThreshold           = 100 * time.Millisecond
 	defaultPingInterval                   = 10 * time.Second
 	defaultWriteTimeout                   = 120 * time.Second
+	defaultHandshakeTimeout               = 10 * time.Second
 	defaultDropInterval                   = 1 * time.Second
 	defaultShutdownTimeout                = 300 * time.Second
 	defaultMaxConns                       = math.MaxInt32
@@ -140,6 +141,7 @@ type Config struct {
 	MinBatchingAgeThreshold        time.Duration
 	PingInterval                   time.Duration
 	PongTimeout                    time.Duration
+	HandshakeTimeout               time.Duration
 	WriteTimeout                   time.Duration
 	DropInterval                   time.Duration
 	ShutdownTimeout                time.Duration
@@ -217,6 +219,13 @@ func (c *Config) ApplyDefaults() {
 		}).Info("PongTimeout < PingInterval * 2; Defaulting PongTimeout.")
 		c.PongTimeout = defaultTimeout
 	}
+	if c.HandshakeTimeout <= 0 {
+		log.WithFields(log.Fields{
+			"value":   c.HandshakeTimeout,
+			"default": defaultHandshakeTimeout,
+		}).Info("Defaulting HandshakeTimeout.")
+		c.HandshakeTimeout = defaultHandshakeTimeout
+	}
 	if c.WriteTimeout <= 0 {
 		log.WithField("default", defaultWriteTimeout).Info("Defaulting write timeout.")
 		c.WriteTimeout = defaultWriteTimeout
@@ -424,7 +433,11 @@ func (s *Server) serve(cxt context.Context) {
 			// Doing TLS, we must do the handshake...
 			tlsConn := conn.(*tls.Conn)
 			logCxt.Debug("TLS connection")
-			err = tlsConn.Handshake()
+			err = func() error {
+				handshakeCxt, handshakeCancel := context.WithTimeout(cxt, s.config.HandshakeTimeout)
+				defer handshakeCancel()
+				return tlsConn.HandshakeContext(handshakeCxt)
+			}()
 			if err != nil {
 				logCxt.WithError(err).Error("TLS handshake error")
 				err = conn.Close()

typha/pkg/syncserver/syncserver_test.go

@@ -41,6 +41,7 @@ var _ = Describe("With zero config", func() {
 			MinBatchingAgeThreshold:        100 * time.Millisecond,
 			PingInterval:                   10 * time.Second,
 			PongTimeout:                    60 * time.Second,
+			HandshakeTimeout:               10 * time.Second,
 			DropInterval:                   time.Second,
 			ShutdownTimeout:                300 * time.Second,
 			ShutdownMaxDropInterval:        time.Second,