Add per endpoint ARP statistics

The ARP stat NetworkUnreachable was removed, and was replaced by
InterfaceHasNoLocalAddress. No stats are recorded when dealing with an
missing endpoint (ErrNotConnected) (because if there is no endpoint,
there is no valid per-endpoint stats).

PiperOrigin-RevId: 353759462

2 files changed, 19 insertions, 21 deletions

diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go
index 2bf76a841..5276878a0 100644
--- a/pkg/tcpip/network/ipv6/ipv6_test.go
+++ b/pkg/tcpip/network/ipv6/ipv6_test.go
@@ -2581,7 +2581,7 @@ func (lm *limitedMatcher) Match(stack.Hook, *stack.PacketBuffer, string, string)
 	return false, false
 }
 
-func getKnownNICIDs(proto *protocol) []tcpip.NICID {
+func knownNICIDs(proto *protocol) []tcpip.NICID {
 	var nicIDs []tcpip.NICID
 
 	for k := range proto.mu.eps {
@@ -2598,29 +2598,27 @@ func TestClearEndpointFromProtocolOnClose(t *testing.T) {
 	proto := s.NetworkProtocolInstance(ProtocolNumber).(*protocol)
 	var nic testInterface
 	ep := proto.NewEndpoint(&nic, nil, nil, nil).(*endpoint)
-	{
-		proto.mu.Lock()
-		foundEP, hasEP := proto.mu.eps[nic.ID()]
-		nicIDs := getKnownNICIDs(proto)
-		proto.mu.Unlock()
-		if !hasEP {
-			t.Fatalf("expected to find the nic id %d in the protocol's known nic ids (%v)", nic.ID(), nicIDs)
-		}
-		if foundEP != ep {
-			t.Fatalf("expected protocol to map endpoint %p to nic id %d, but endpoint %p was found instead", ep, nic.ID(), foundEP)
-		}
+	var nicIDs []tcpip.NICID
+
+	proto.mu.Lock()
+	foundEP, hasEndpointBeforeClose := proto.mu.eps[nic.ID()]
+	nicIDs = knownNICIDs(proto)
+	proto.mu.Unlock()
+	if !hasEndpointBeforeClose {
+		t.Fatalf("expected to find the nic id %d in the protocol's known nic ids (%v)", nic.ID(), nicIDs)
+	}
+	if foundEP != ep {
+		t.Fatalf("found an incorrect endpoint mapped to nic id %d", nic.ID())
 	}
 
 	ep.Close()
 
-	{
-		proto.mu.Lock()
-		_, hasEP := proto.mu.eps[nic.ID()]
-		nicIDs := getKnownNICIDs(proto)
-		proto.mu.Unlock()
-		if hasEP {
-			t.Fatalf("unexpectedly found an endpoint mapped to the nic id %d in the protocol's known nic ids (%v)", nic.ID(), nicIDs)
-		}
+	proto.mu.Lock()
+	_, hasEndpointAfterClose := proto.mu.eps[nic.ID()]
+	nicIDs = knownNICIDs(proto)
+	proto.mu.Unlock()
+	if hasEndpointAfterClose {
+		t.Fatalf("unexpectedly found an endpoint mapped to the nic id %d in the protocol's known nic ids (%v)", nic.ID(), nicIDs)
 	}
 }
 
diff --git a/pkg/tcpip/network/ipv6/stats.go b/pkg/tcpip/network/ipv6/stats.go
index a2f2f4f78..0839be3cd 100644
--- a/pkg/tcpip/network/ipv6/stats.go
+++ b/pkg/tcpip/network/ipv6/stats.go
@@ -32,7 +32,7 @@ type Stats struct {
 }
 
 // IsNetworkEndpointStats implements stack.NetworkEndpointStats.
-func (s *Stats) IsNetworkEndpointStats() {}
+func (*Stats) IsNetworkEndpointStats() {}
 
 // IPStats implements stack.IPNetworkEndointStats
 func (s *Stats) IPStats() *tcpip.IPStats {