Merge release-20200219.0-86-gc15b851 (automated)

5 files changed, 45 insertions, 38 deletions

diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index ebb6c5e3b..13354d884 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -551,11 +551,13 @@ type TransportEndpointInfo struct {
 	RegisterNICID tcpip.NICID
 }
 
-// AddrNetProto unwraps the specified address if it is a V4-mapped V6 address
-// and returns the network protocol number to be used to communicate with the
-// specified address. It returns an error if the passed address is incompatible
-// with the receiver.
-func (e *TransportEndpointInfo) AddrNetProto(addr tcpip.FullAddress, v6only bool) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) {
+// AddrNetProtoLocked unwraps the specified address if it is a V4-mapped V6
+// address and returns the network protocol number to be used to communicate
+// with the specified address. It returns an error if the passed address is
+// incompatible with the receiver.
+//
+// Preconditon: the parent endpoint mu must be held while calling this method.
+func (e *TransportEndpointInfo) AddrNetProtoLocked(addr tcpip.FullAddress, v6only bool) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) {
 	netProto := e.NetProto
 	switch len(addr.Addr) {
 	case header.IPv4AddressSize:
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 426da1ee6..2a396e9bc 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -291,15 +291,13 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c
 			nicID = e.BindNICID
 		}
 
-		toCopy := *to
-		to = &toCopy
-		netProto, err := e.checkV4Mapped(to)
+		dst, netProto, err := e.checkV4MappedLocked(*to)
 		if err != nil {
 			return 0, nil, err
 		}
 
-		// Find the enpoint.
-		r, err := e.stack.FindRoute(nicID, e.BindAddr, to.Addr, netProto, false /* multicastLoop */)
+		// Find the endpoint.
+		r, err := e.stack.FindRoute(nicID, e.BindAddr, dst.Addr, netProto, false /* multicastLoop */)
 		if err != nil {
 			return 0, nil, err
 		}
@@ -480,13 +478,14 @@ func send6(r *stack.Route, ident uint16, data buffer.View, ttl uint8) *tcpip.Err
 	})
 }
 
-func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress) (tcpip.NetworkProtocolNumber, *tcpip.Error) {
-	unwrapped, netProto, err := e.TransportEndpointInfo.AddrNetProto(*addr, false /* v6only */)
+// checkV4MappedLocked determines the effective network protocol and converts
+// addr to its canonical form.
+func (e *endpoint) checkV4MappedLocked(addr tcpip.FullAddress) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) {
+	unwrapped, netProto, err := e.TransportEndpointInfo.AddrNetProtoLocked(addr, false /* v6only */)
 	if err != nil {
-		return 0, err
+		return tcpip.FullAddress{}, 0, err
 	}
-	*addr = unwrapped
-	return netProto, nil
+	return unwrapped, netProto, nil
 }
 
 // Disconnect implements tcpip.Endpoint.Disconnect.
@@ -517,7 +516,7 @@ func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 		return tcpip.ErrInvalidEndpointState
 	}
 
-	netProto, err := e.checkV4Mapped(&addr)
+	addr, netProto, err := e.checkV4MappedLocked(addr)
 	if err != nil {
 		return err
 	}
@@ -630,7 +629,7 @@ func (e *endpoint) bindLocked(addr tcpip.FullAddress) *tcpip.Error {
 		return tcpip.ErrInvalidEndpointState
 	}
 
-	netProto, err := e.checkV4Mapped(&addr)
+	addr, netProto, err := e.checkV4MappedLocked(addr)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index 8b9154e69..40cc664c0 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -1874,13 +1874,14 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	}
 }
 
-func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress) (tcpip.NetworkProtocolNumber, *tcpip.Error) {
-	unwrapped, netProto, err := e.TransportEndpointInfo.AddrNetProto(*addr, e.v6only)
+// checkV4MappedLocked determines the effective network protocol and converts
+// addr to its canonical form.
+func (e *endpoint) checkV4MappedLocked(addr tcpip.FullAddress) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) {
+	unwrapped, netProto, err := e.TransportEndpointInfo.AddrNetProtoLocked(addr, e.v6only)
 	if err != nil {
-		return 0, err
+		return tcpip.FullAddress{}, 0, err
 	}
-	*addr = unwrapped
-	return netProto, nil
+	return unwrapped, netProto, nil
 }
 
 // Disconnect implements tcpip.Endpoint.Disconnect.
@@ -1910,7 +1911,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) *tc
 
 	connectingAddr := addr.Addr
 
-	netProto, err := e.checkV4Mapped(&addr)
+	addr, netProto, err := e.checkV4MappedLocked(addr)
 	if err != nil {
 		return err
 	}
@@ -2276,7 +2277,7 @@ func (e *endpoint) bindLocked(addr tcpip.FullAddress) (err *tcpip.Error) {
 	}
 
 	e.BindAddr = addr.Addr
-	netProto, err := e.checkV4Mapped(&addr)
+	addr, netProto, err := e.checkV4MappedLocked(addr)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 1c6a600b8..0af4514e1 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -443,19 +443,19 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c
 			return 0, nil, tcpip.ErrBroadcastDisabled
 		}
 
-		netProto, err := e.checkV4Mapped(to)
+		dst, netProto, err := e.checkV4MappedLocked(*to)
 		if err != nil {
 			return 0, nil, err
 		}
 
-		r, _, err := e.connectRoute(nicID, *to, netProto)
+		r, _, err := e.connectRoute(nicID, dst, netProto)
 		if err != nil {
 			return 0, nil, err
 		}
 		defer r.Release()
 
 		route = &r
-		dstPort = to.Port
+		dstPort = dst.Port
 	}
 
 	if route.IsResolutionRequired() {
@@ -566,7 +566,7 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 		defer e.mu.Unlock()
 
 		fa := tcpip.FullAddress{Addr: v.InterfaceAddr}
-		netProto, err := e.checkV4Mapped(&fa)
+		fa, netProto, err := e.checkV4MappedLocked(fa)
 		if err != nil {
 			return err
 		}
@@ -927,13 +927,14 @@ func sendUDP(r *stack.Route, data buffer.VectorisedView, localPort, remotePort u
 	return nil
 }
 
-func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress) (tcpip.NetworkProtocolNumber, *tcpip.Error) {
-	unwrapped, netProto, err := e.TransportEndpointInfo.AddrNetProto(*addr, e.v6only)
+// checkV4MappedLocked determines the effective network protocol and converts
+// addr to its canonical form.
+func (e *endpoint) checkV4MappedLocked(addr tcpip.FullAddress) (tcpip.FullAddress, tcpip.NetworkProtocolNumber, *tcpip.Error) {
+	unwrapped, netProto, err := e.TransportEndpointInfo.AddrNetProtoLocked(addr, e.v6only)
 	if err != nil {
-		return 0, err
+		return tcpip.FullAddress{}, 0, err
 	}
-	*addr = unwrapped
-	return netProto, nil
+	return unwrapped, netProto, nil
 }
 
 // Disconnect implements tcpip.Endpoint.Disconnect.
@@ -981,10 +982,6 @@ func (e *endpoint) Disconnect() *tcpip.Error {
 
 // Connect connects the endpoint to its peer. Specifying a NIC is optional.
 func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
-	netProto, err := e.checkV4Mapped(&addr)
-	if err != nil {
-		return err
-	}
 	if addr.Port == 0 {
 		// We don't support connecting to port zero.
 		return tcpip.ErrInvalidEndpointState
@@ -1012,6 +1009,11 @@ func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 		return tcpip.ErrInvalidEndpointState
 	}
 
+	addr, netProto, err := e.checkV4MappedLocked(addr)
+	if err != nil {
+		return err
+	}
+
 	r, nicID, err := e.connectRoute(nicID, addr, netProto)
 	if err != nil {
 		return err
@@ -1139,7 +1141,7 @@ func (e *endpoint) bindLocked(addr tcpip.FullAddress) *tcpip.Error {
 		return tcpip.ErrInvalidEndpointState
 	}
 
-	netProto, err := e.checkV4Mapped(&addr)
+	addr, netProto, err := e.checkV4MappedLocked(addr)
 	if err != nil {
 		return err
 	}
diff --git a/pkg/tcpip/transport/udp/endpoint_state.go b/pkg/tcpip/transport/udp/endpoint_state.go
index 43fb047ed..466bd9381 100644
--- a/pkg/tcpip/transport/udp/endpoint_state.go
+++ b/pkg/tcpip/transport/udp/endpoint_state.go
@@ -69,6 +69,9 @@ func (e *endpoint) afterLoad() {
 
 // Resume implements tcpip.ResumableEndpoint.Resume.
 func (e *endpoint) Resume(s *stack.Stack) {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
 	e.stack = s
 
 	for _, m := range e.multicastMemberships {