3 files changed, 27 insertions, 2 deletions
diff --git a/pkg/sentry/inet/BUILD b/pkg/sentry/inet/BUILD
index 07bf39fed..5bba9de0b 100644
--- a/pkg/sentry/inet/BUILD
+++ b/pkg/sentry/inet/BUILD
@@ -15,6 +15,7 @@ go_library(
     ],
     deps = [
         "//pkg/context",
+        "//pkg/tcpip",
         "//pkg/tcpip/stack",
     ],
 )
diff --git a/pkg/sentry/inet/inet.go b/pkg/sentry/inet/inet.go
index c0b4831d1..fbe6d6aa6 100644
--- a/pkg/sentry/inet/inet.go
+++ b/pkg/sentry/inet/inet.go
@@ -15,7 +15,10 @@
 // Package inet defines semantics for IP stacks.
 package inet
 
-import "gvisor.dev/gvisor/pkg/tcpip/stack"
+import (
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+)
 
 // Stack represents a TCP/IP stack.
 type Stack interface {
@@ -80,6 +83,12 @@ type Stack interface {
 	// RestoreCleanupEndpoints adds endpoints to cleanup tracking. This is useful
 	// for restoring a stack after a save.
 	RestoreCleanupEndpoints([]stack.TransportEndpoint)
+
+	// Forwarding returns if packet forwarding between NICs is enabled.
+	Forwarding(protocol tcpip.NetworkProtocolNumber) bool
+
+	// SetForwarding enables or disables packet forwarding between NICs.
+	SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error
 }
 
 // Interface contains information about a network interface.
diff --git a/pkg/sentry/inet/test_stack.go b/pkg/sentry/inet/test_stack.go
index 9771f01fc..1779cc6f3 100644
--- a/pkg/sentry/inet/test_stack.go
+++ b/pkg/sentry/inet/test_stack.go
@@ -14,7 +14,10 @@
 
 package inet
 
-import "gvisor.dev/gvisor/pkg/tcpip/stack"
+import (
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+)
 
 // TestStack is a dummy implementation of Stack for tests.
 type TestStack struct {
@@ -26,6 +29,7 @@ type TestStack struct {
 	TCPSendBufSize    TCPBufferSize
 	TCPSACKFlag       bool
 	Recovery          TCPLossRecovery
+	IPForwarding      bool
 }
 
 // NewTestStack returns a TestStack with no network interfaces. The value of
@@ -128,3 +132,14 @@ func (s *TestStack) CleanupEndpoints() []stack.TransportEndpoint {
 
 // RestoreCleanupEndpoints implements inet.Stack.RestoreCleanupEndpoints.
 func (s *TestStack) RestoreCleanupEndpoints([]stack.TransportEndpoint) {}
+
+// Forwarding implements inet.Stack.Forwarding.
+func (s *TestStack) Forwarding(protocol tcpip.NetworkProtocolNumber) bool {
+	return s.IPForwarding
+}
+
+// SetForwarding implements inet.Stack.SetForwarding.
+func (s *TestStack) SetForwarding(protocol tcpip.NetworkProtocolNumber, enable bool) error {
+	s.IPForwarding = enable
+	return nil
+}