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/ipv4/stats.go b/pkg/tcpip/network/ipv4/stats.go
index 7620728f9..bee72c649 100644
--- a/pkg/tcpip/network/ipv4/stats.go
+++ b/pkg/tcpip/network/ipv4/stats.go
@@ -35,7 +35,7 @@ type Stats struct {
 }
 
 // IsNetworkEndpointStats implements stack.NetworkEndpointStats.
-func (s *Stats) IsNetworkEndpointStats() {}
+func (*Stats) IsNetworkEndpointStats() {}
 
 // IPStats implements stack.IPNetworkEndointStats
 func (s *Stats) IPStats() *tcpip.IPStats {
diff --git a/pkg/tcpip/network/ipv4/stats_test.go b/pkg/tcpip/network/ipv4/stats_test.go
index 84641bcf4..b28e7dcde 100644
--- a/pkg/tcpip/network/ipv4/stats_test.go
+++ b/pkg/tcpip/network/ipv4/stats_test.go
@@ -34,7 +34,7 @@ func (t *testInterface) ID() tcpip.NICID {
 	return t.nicID
 }
 
-func getKnownNICIDs(proto *protocol) []tcpip.NICID {
+func knownNICIDs(proto *protocol) []tcpip.NICID {
 	var nicIDs []tcpip.NICID
 
 	for k := range proto.mu.eps {
@@ -51,30 +51,28 @@ func TestClearEndpointFromProtocolOnClose(t *testing.T) {
 	proto := s.NetworkProtocolInstance(ProtocolNumber).(*protocol)
 	nic := testInterface{nicID: 1}
 	ep := proto.NewEndpoint(&nic, nil, nil, nil).(*endpoint)
-	{
-		proto.mu.Lock()
-		foundEP, hasEP := proto.mu.eps[nic.ID()]
-		nicIDs := getKnownNICIDs(proto)
-		proto.mu.Unlock()
+	var nicIDs []tcpip.NICID
+
+	proto.mu.Lock()
+	foundEP, hasEndpointBeforeClose := proto.mu.eps[nic.ID()]
+	nicIDs = knownNICIDs(proto)
+	proto.mu.Unlock()
 
-		if !hasEP {
-			t.Fatalf("expected to find the nic id %d in the protocol's endpoint map (%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)
-		}
+	if !hasEndpointBeforeClose {
+		t.Fatalf("expected to find the nic id %d in the protocol's endpoint map (%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()
+	_, hasEP := proto.mu.eps[nic.ID()]
+	nicIDs = knownNICIDs(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)
 	}
 }