netstack: disconnect an unix socket only if the address family is AF_UNSPEC

Linux allows to call connect for ANY and the zero port.

PiperOrigin-RevId: 263892534

6 files changed, 25 insertions, 19 deletions

diff --git a/pkg/tcpip/stack/transport_test.go b/pkg/tcpip/stack/transport_test.go
index 8146e8444..1c811ab68 100644
--- a/pkg/tcpip/stack/transport_test.go
+++ b/pkg/tcpip/stack/transport_test.go
@@ -105,6 +105,11 @@ func (*fakeTransportEndpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	return tcpip.ErrInvalidEndpointState
 }
 
+// Disconnect implements tcpip.Endpoint.Disconnect.
+func (*fakeTransportEndpoint) Disconnect() *tcpip.Error {
+	return tcpip.ErrNotSupported
+}
+
 func (f *fakeTransportEndpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 	f.peerAddr = addr.Addr
 
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index ba2dd85b8..29a6025d9 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -358,6 +358,9 @@ type Endpoint interface {
 	// ErrAddressFamilyNotSupported must be returned.
 	Connect(address FullAddress) *Error
 
+	// Disconnect disconnects the endpoint from its peer.
+	Disconnect() *Error
+
 	// Shutdown closes the read and/or write end of the endpoint connection
 	// to its peer.
 	Shutdown(flags ShutdownFlags) *Error
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 2e8d5d4bf..451d3880e 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -428,16 +428,16 @@ func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress, allowMismatch bool) (t
 	return netProto, nil
 }
 
+// Disconnect implements tcpip.Endpoint.Disconnect.
+func (*endpoint) Disconnect() *tcpip.Error {
+	return tcpip.ErrNotSupported
+}
+
 // Connect connects the endpoint to its peer. Specifying a NIC is optional.
 func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 
-	if addr.Addr == "" {
-		// AF_UNSPEC isn't supported.
-		return tcpip.ErrAddressFamilyNotSupported
-	}
-
 	nicid := addr.NIC
 	localPort := uint16(0)
 	switch e.state {
diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go
index 53c9515a4..13e17e2a6 100644
--- a/pkg/tcpip/transport/raw/endpoint.go
+++ b/pkg/tcpip/transport/raw/endpoint.go
@@ -349,16 +349,16 @@ func (ep *endpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error)
 	return 0, tcpip.ControlMessages{}, nil
 }
 
+// Disconnect implements tcpip.Endpoint.Disconnect.
+func (*endpoint) Disconnect() *tcpip.Error {
+	return tcpip.ErrNotSupported
+}
+
 // Connect implements tcpip.Endpoint.Connect.
 func (ep *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 	ep.mu.Lock()
 	defer ep.mu.Unlock()
 
-	if addr.Addr == "" {
-		// AF_UNSPEC isn't supported.
-		return tcpip.ErrAddressFamilyNotSupported
-	}
-
 	if ep.closed {
 		return tcpip.ErrInvalidEndpointState
 	}
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index e5f835c20..24b32e4af 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -1362,13 +1362,13 @@ func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress) (tcpip.NetworkProtocol
 	return netProto, nil
 }
 
+// Disconnect implements tcpip.Endpoint.Disconnect.
+func (*endpoint) Disconnect() *tcpip.Error {
+	return tcpip.ErrNotSupported
+}
+
 // Connect connects the endpoint to its peer.
 func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
-	if addr.Addr == "" && addr.Port == 0 {
-		// AF_UNSPEC isn't supported.
-		return tcpip.ErrAddressFamilyNotSupported
-	}
-
 	return e.connect(addr, true, true)
 }
 
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 640bb8667..8b3356406 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -711,7 +711,8 @@ func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress, allowMismatch bool) (t
 	return netProto, nil
 }
 
-func (e *endpoint) disconnect() *tcpip.Error {
+// Disconnect implements tcpip.Endpoint.Disconnect.
+func (e *endpoint) Disconnect() *tcpip.Error {
 	e.mu.Lock()
 	defer e.mu.Unlock()
 
@@ -750,9 +751,6 @@ func (e *endpoint) Connect(addr tcpip.FullAddress) *tcpip.Error {
 	if err != nil {
 		return err
 	}
-	if addr.Addr == "" {
-		return e.disconnect()
-	}
 	if addr.Port == 0 {
 		// We don't support connecting to port zero.
 		return tcpip.ErrInvalidEndpointState