Merge release-20210125.0-91-gc19e049f2 (automated)

3 files changed, 36 insertions, 8 deletions

diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 6f2a0e487..a90d027f2 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -441,6 +441,13 @@ func (n *NIC) setSpoofing(enable bool) {
 	n.mu.Unlock()
 }
 
+// Spoofing implements NetworkInterface.
+func (n *NIC) Spoofing() bool {
+	n.mu.RLock()
+	defer n.mu.RUnlock()
+	return n.mu.spoofing
+}
+
 // primaryAddress returns an address that can be used to communicate with
 // remoteAddr.
 func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber, remoteAddr tcpip.Address) AssignableAddressEndpoint {
@@ -994,3 +1001,17 @@ func (n *NIC) HandleNeighborConfirmation(protocol tcpip.NetworkProtocolNumber, a
 
 	return &tcpip.ErrNotSupported{}
 }
+
+// CheckLocalAddress implements NetworkInterface.
+func (n *NIC) CheckLocalAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) bool {
+	if n.Spoofing() {
+		return true
+	}
+
+	if addressEndpoint := n.getAddressOrCreateTempInner(protocol, addr, false /* createTemp */, NeverPrimaryEndpoint); addressEndpoint != nil {
+		addressEndpoint.DecRef()
+		return true
+	}
+
+	return false
+}
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go
index d589f798d..2bc1c4270 100644
--- a/pkg/tcpip/stack/registration.go
+++ b/pkg/tcpip/stack/registration.go
@@ -514,8 +514,19 @@ type NetworkInterface interface {
 	Enabled() bool
 
 	// Promiscuous returns true if the interface is in promiscuous mode.
+	//
+	// When in promiscuous mode, the interface should accept all packets.
 	Promiscuous() bool
 
+	// Spoofing returns true if the interface is in spoofing mode.
+	//
+	// When in spoofing mode, the interface should consider all addresses as
+	// assigned to it.
+	Spoofing() bool
+
+	// CheckLocalAddress returns true if the address exists on the interface.
+	CheckLocalAddress(tcpip.NetworkProtocolNumber, tcpip.Address) bool
+
 	// WritePacketToRemote writes the packet to the given remote link address.
 	WritePacketToRemote(tcpip.LinkAddress, *GSO, tcpip.NetworkProtocolNumber, *PacketBuffer) tcpip.Error
 
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 035ab33ca..198e59c77 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -1498,20 +1498,16 @@ func (s *Stack) CheckLocalAddress(nicID tcpip.NICID, protocol tcpip.NetworkProto
 			return 0
 		}
 
-		addressEndpoint := nic.findEndpoint(protocol, addr, CanBePrimaryEndpoint)
-		if addressEndpoint == nil {
-			return 0
+		if nic.CheckLocalAddress(protocol, addr) {
+			return nic.id
 		}
 
-		addressEndpoint.DecRef()
-
-		return nic.id
+		return 0
 	}
 
 	// Go through all the NICs.
 	for _, nic := range s.nics {
-		if addressEndpoint := nic.findEndpoint(protocol, addr, CanBePrimaryEndpoint); addressEndpoint != nil {
-			addressEndpoint.DecRef()
+		if nic.CheckLocalAddress(protocol, addr) {
 			return nic.id
 		}
 	}