Internal change.

PiperOrigin-RevId: 312559963

4 files changed, 117 insertions, 66 deletions

diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index 45e930ad8..b7b227328 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -110,6 +110,71 @@ var (
 	ErrAddressFamilyNotSupported = &Error{msg: "address family not supported by protocol"}
 )
 
+var messageToError map[string]*Error
+
+var populate sync.Once
+
+// StringToError converts an error message to the error.
+func StringToError(s string) *Error {
+	populate.Do(func() {
+		var errors = []*Error{
+			ErrUnknownProtocol,
+			ErrUnknownNICID,
+			ErrUnknownDevice,
+			ErrUnknownProtocolOption,
+			ErrDuplicateNICID,
+			ErrDuplicateAddress,
+			ErrNoRoute,
+			ErrBadLinkEndpoint,
+			ErrAlreadyBound,
+			ErrInvalidEndpointState,
+			ErrAlreadyConnecting,
+			ErrAlreadyConnected,
+			ErrNoPortAvailable,
+			ErrPortInUse,
+			ErrBadLocalAddress,
+			ErrClosedForSend,
+			ErrClosedForReceive,
+			ErrWouldBlock,
+			ErrConnectionRefused,
+			ErrTimeout,
+			ErrAborted,
+			ErrConnectStarted,
+			ErrDestinationRequired,
+			ErrNotSupported,
+			ErrQueueSizeNotSupported,
+			ErrNotConnected,
+			ErrConnectionReset,
+			ErrConnectionAborted,
+			ErrNoSuchFile,
+			ErrInvalidOptionValue,
+			ErrNoLinkAddress,
+			ErrBadAddress,
+			ErrNetworkUnreachable,
+			ErrMessageTooLong,
+			ErrNoBufferSpace,
+			ErrBroadcastDisabled,
+			ErrNotPermitted,
+			ErrAddressFamilyNotSupported,
+		}
+
+		messageToError = make(map[string]*Error)
+		for _, e := range errors {
+			if messageToError[e.String()] != nil {
+				panic("tcpip errors with duplicated message: " + e.String())
+			}
+			messageToError[e.String()] = e
+		}
+	})
+
+	e, ok := messageToError[s]
+	if !ok {
+		panic("unknown error message: " + s)
+	}
+
+	return e
+}
+
 // Errors related to Subnet
 var (
 	errSubnetLengthMismatch = errors.New("subnet length of address and mask differ")
diff --git a/pkg/tcpip/transport/tcp/endpoint_state.go b/pkg/tcpip/transport/tcp/endpoint_state.go
index 8b7562396..fc43c11e2 100644
--- a/pkg/tcpip/transport/tcp/endpoint_state.go
+++ b/pkg/tcpip/transport/tcp/endpoint_state.go
@@ -314,7 +314,7 @@ func (e *endpoint) loadLastError(s string) {
 		return
 	}
 
-	e.lastError = loadError(s)
+	e.lastError = tcpip.StringToError(s)
 }
 
 // saveHardError is invoked by stateify.
@@ -332,71 +332,7 @@ func (e *EndpointInfo) loadHardError(s string) {
 		return
 	}
 
-	e.HardError = loadError(s)
-}
-
-var messageToError map[string]*tcpip.Error
-
-var populate sync.Once
-
-func loadError(s string) *tcpip.Error {
-	populate.Do(func() {
-		var errors = []*tcpip.Error{
-			tcpip.ErrUnknownProtocol,
-			tcpip.ErrUnknownNICID,
-			tcpip.ErrUnknownDevice,
-			tcpip.ErrUnknownProtocolOption,
-			tcpip.ErrDuplicateNICID,
-			tcpip.ErrDuplicateAddress,
-			tcpip.ErrNoRoute,
-			tcpip.ErrBadLinkEndpoint,
-			tcpip.ErrAlreadyBound,
-			tcpip.ErrInvalidEndpointState,
-			tcpip.ErrAlreadyConnecting,
-			tcpip.ErrAlreadyConnected,
-			tcpip.ErrNoPortAvailable,
-			tcpip.ErrPortInUse,
-			tcpip.ErrBadLocalAddress,
-			tcpip.ErrClosedForSend,
-			tcpip.ErrClosedForReceive,
-			tcpip.ErrWouldBlock,
-			tcpip.ErrConnectionRefused,
-			tcpip.ErrTimeout,
-			tcpip.ErrAborted,
-			tcpip.ErrConnectStarted,
-			tcpip.ErrDestinationRequired,
-			tcpip.ErrNotSupported,
-			tcpip.ErrQueueSizeNotSupported,
-			tcpip.ErrNotConnected,
-			tcpip.ErrConnectionReset,
-			tcpip.ErrConnectionAborted,
-			tcpip.ErrNoSuchFile,
-			tcpip.ErrInvalidOptionValue,
-			tcpip.ErrNoLinkAddress,
-			tcpip.ErrBadAddress,
-			tcpip.ErrNetworkUnreachable,
-			tcpip.ErrMessageTooLong,
-			tcpip.ErrNoBufferSpace,
-			tcpip.ErrBroadcastDisabled,
-			tcpip.ErrNotPermitted,
-			tcpip.ErrAddressFamilyNotSupported,
-		}
-
-		messageToError = make(map[string]*tcpip.Error)
-		for _, e := range errors {
-			if messageToError[e.String()] != nil {
-				panic("tcpip errors with duplicated message: " + e.String())
-			}
-			messageToError[e.String()] = e
-		}
-	})
-
-	e, ok := messageToError[s]
-	if !ok {
-		panic("unknown error message: " + s)
-	}
-
-	return e
+	e.HardError = tcpip.StringToError(s)
 }
 
 // saveMeasureTime is invoked by stateify.
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 756ab913a..647b2067a 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -106,6 +106,9 @@ type endpoint struct {
 	bindToDevice   tcpip.NICID
 	broadcast      bool
 
+	lastErrorMu sync.Mutex   `state:"nosave"`
+	lastError   *tcpip.Error `state:".(string)"`
+
 	// Values used to reserve a port or register a transport endpoint.
 	// (which ever happens first).
 	boundBindToDevice tcpip.NICID
@@ -188,6 +191,15 @@ func (e *endpoint) UniqueID() uint64 {
 	return e.uniqueID
 }
 
+func (e *endpoint) takeLastError() *tcpip.Error {
+	e.lastErrorMu.Lock()
+	defer e.lastErrorMu.Unlock()
+
+	err := e.lastError
+	e.lastError = nil
+	return err
+}
+
 // Abort implements stack.TransportEndpoint.Abort.
 func (e *endpoint) Abort() {
 	e.Close()
@@ -243,6 +255,10 @@ func (e *endpoint) IPTables() (stack.IPTables, error) {
 // Read reads data from the endpoint. This method does not block if
 // there is no data pending.
 func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMessages, *tcpip.Error) {
+	if err := e.takeLastError(); err != nil {
+		return buffer.View{}, tcpip.ControlMessages{}, err
+	}
+
 	e.rcvMu.Lock()
 
 	if e.rcvList.Empty() {
@@ -382,6 +398,10 @@ func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c
 }
 
 func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
+	if err := e.takeLastError(); err != nil {
+		return 0, nil, err
+	}
+
 	// MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.)
 	if opts.More {
 		return 0, nil, tcpip.ErrInvalidOptionValue
@@ -853,6 +873,7 @@ func (e *endpoint) GetSockOptInt(opt tcpip.SockOptInt) (int, *tcpip.Error) {
 func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	switch o := opt.(type) {
 	case tcpip.ErrorOption:
+		return e.takeLastError()
 	case *tcpip.MulticastInterfaceOption:
 		e.mu.Lock()
 		*o = tcpip.MulticastInterfaceOption{
@@ -1316,6 +1337,17 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, pk
 
 // HandleControlPacket implements stack.TransportEndpoint.HandleControlPacket.
 func (e *endpoint) HandleControlPacket(id stack.TransportEndpointID, typ stack.ControlType, extra uint32, pkt stack.PacketBuffer) {
+	if typ == stack.ControlPortUnreachable {
+		e.mu.RLock()
+		defer e.mu.RUnlock()
+
+		if e.state == StateConnected {
+			e.lastErrorMu.Lock()
+			defer e.lastErrorMu.Unlock()
+
+			e.lastError = tcpip.ErrConnectionRefused
+		}
+	}
 }
 
 // State implements tcpip.Endpoint.State.
diff --git a/pkg/tcpip/transport/udp/endpoint_state.go b/pkg/tcpip/transport/udp/endpoint_state.go
index 466bd9381..851e6b635 100644
--- a/pkg/tcpip/transport/udp/endpoint_state.go
+++ b/pkg/tcpip/transport/udp/endpoint_state.go
@@ -37,6 +37,24 @@ func (u *udpPacket) loadData(data buffer.VectorisedView) {
 	u.data = data
 }
 
+// saveLastError is invoked by stateify.
+func (e *endpoint) saveLastError() string {
+	if e.lastError == nil {
+		return ""
+	}
+
+	return e.lastError.String()
+}
+
+// loadLastError is invoked by stateify.
+func (e *endpoint) loadLastError(s string) {
+	if s == "" {
+		return
+	}
+
+	e.lastError = tcpip.StringToError(s)
+}
+
 // beforeSave is invoked by stateify.
 func (e *endpoint) beforeSave() {
 	// Stop incoming packets from being handled (and mutate endpoint state).