Add endpoint tracking to the stack.

In the future this will replace DanglingEndpoints. DanglingEndpoints must be
kept for now due to issues with save/restore.

This is arguably a cleaner design and allows the stack to know which transport
endpoints might still be using its link endpoints.

Updates #837

PiperOrigin-RevId: 277386633

2 files changed, 8 insertions, 4 deletions

diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index ce8307cee..8a3ca0f1b 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -686,7 +686,7 @@ func (e *endpoint) Close() {
 	// in Listen() when trying to register.
 	if e.state == StateListen && e.isPortReserved {
 		if e.isRegistered {
-			e.stack.UnregisterTransportEndpoint(e.boundNICID, e.effectiveNetProtos, ProtocolNumber, e.ID, e, e.bindToDevice)
+			e.stack.StartTransportEndpointCleanup(e.boundNICID, e.effectiveNetProtos, ProtocolNumber, e.ID, e, e.bindToDevice)
 			e.isRegistered = false
 		}
 
@@ -747,7 +747,7 @@ func (e *endpoint) cleanupLocked() {
 	e.workerCleanup = false
 
 	if e.isRegistered {
-		e.stack.UnregisterTransportEndpoint(e.boundNICID, e.effectiveNetProtos, ProtocolNumber, e.ID, e, e.bindToDevice)
+		e.stack.StartTransportEndpointCleanup(e.boundNICID, e.effectiveNetProtos, ProtocolNumber, e.ID, e, e.bindToDevice)
 		e.isRegistered = false
 	}
 
@@ -757,6 +757,7 @@ func (e *endpoint) cleanupLocked() {
 	}
 
 	e.route.Release()
+	e.stack.CompleteTransportEndpointCleanup(e)
 	tcpip.DeleteDanglingEndpoint(e)
 }
 
diff --git a/pkg/tcpip/transport/tcp/endpoint_state.go b/pkg/tcpip/transport/tcp/endpoint_state.go
index eae17237e..19f003b6b 100644
--- a/pkg/tcpip/transport/tcp/endpoint_state.go
+++ b/pkg/tcpip/transport/tcp/endpoint_state.go
@@ -193,8 +193,10 @@ func (e *endpoint) Resume(s *stack.Stack) {
 		if len(e.BindAddr) == 0 {
 			e.BindAddr = e.ID.LocalAddress
 		}
-		if err := e.Bind(tcpip.FullAddress{Addr: e.BindAddr, Port: e.ID.LocalPort}); err != nil {
-			panic("endpoint binding failed: " + err.String())
+		addr := e.BindAddr
+		port := e.ID.LocalPort
+		if err := e.Bind(tcpip.FullAddress{Addr: addr, Port: port}); err != nil {
+			panic(fmt.Sprintf("endpoint binding [%v]:%d failed: %v", addr, port, err))
 		}
 	}
 
@@ -265,6 +267,7 @@ func (e *endpoint) Resume(s *stack.Stack) {
 		}
 		fallthrough
 	case StateError:
+		e.stack.CompleteTransportEndpointCleanup(e)
 		tcpip.DeleteDanglingEndpoint(e)
 	}
 }