Split PacketCount to Egress and Ingress

Also, 1 packet may be counted in N topologies, so you can't rely on the
sum of all packet counts across topologies having any relation to the
sampling data.

probe/sniff/sniffer.go

@@ -119,8 +119,11 @@ func interpolateCounts(r report.Report) {
 	factor := 1.0 / rate
 	for _, topology := range r.Topologies() {
 		for _, emd := range topology.EdgeMetadatas {
-			if emd.PacketCount != nil {
-				*emd.PacketCount = uint64(float64(*emd.PacketCount) * factor)
+			if emd.EgressPacketCount != nil {
+				*emd.EgressPacketCount = uint64(float64(*emd.EgressPacketCount) * factor)
+			}
+			if emd.IngressPacketCount != nil {
+				*emd.IngressPacketCount = uint64(float64(*emd.IngressPacketCount) * factor)
 			}
 			if emd.EgressByteCount != nil {
 				*emd.EgressByteCount = uint64(float64(*emd.EgressByteCount) * factor)
@@ -261,17 +264,21 @@ func (s *Sniffer) Merge(p Packet, rpt report.Report) {
 		}
 
 		emd := rpt.Address.EdgeMetadatas[edgeID]
-		if emd.PacketCount == nil {
-			emd.PacketCount = new(uint64)
-		}
-		*emd.PacketCount++
 
 		if egress {
+			if emd.EgressPacketCount == nil {
+				emd.EgressPacketCount = new(uint64)
+			}
+			*emd.EgressPacketCount++
 			if emd.EgressByteCount == nil {
 				emd.EgressByteCount = new(uint64)
 			}
 			*emd.EgressByteCount += uint64(p.Network)
 		} else {
+			if emd.IngressPacketCount == nil {
+				emd.IngressPacketCount = new(uint64)
+			}
+			*emd.IngressPacketCount++
 			if emd.IngressByteCount == nil {
 				emd.IngressByteCount = new(uint64)
 			}
@@ -296,17 +303,21 @@ func (s *Sniffer) Merge(p Packet, rpt report.Report) {
 		}
 
 		emd := rpt.Endpoint.EdgeMetadatas[edgeID]
-		if emd.PacketCount == nil {
-			emd.PacketCount = new(uint64)
-		}
-		*emd.PacketCount++
 
 		if egress {
+			if emd.EgressPacketCount == nil {
+				emd.EgressPacketCount = new(uint64)
+			}
+			*emd.EgressPacketCount++
 			if emd.EgressByteCount == nil {
 				emd.EgressByteCount = new(uint64)
 			}
 			*emd.EgressByteCount += uint64(p.Transport)
 		} else {
+			if emd.IngressPacketCount == nil {
+				emd.IngressPacketCount = new(uint64)
+			}
+			*emd.IngressPacketCount++
 			if emd.IngressByteCount == nil {
 				emd.IngressByteCount = new(uint64)
 			}

probe/sniff/sniffer_internal_test.go

@@ -22,9 +22,10 @@ func TestInterpolateCounts(t *testing.T) {
 	r.Sampling.Count = samplingCount
 	r.Sampling.Total = samplingTotal
 	r.Endpoint.EdgeMetadatas[edgeID] = report.EdgeMetadata{
-		PacketCount:      newu64(packetCount),
-		IngressByteCount: newu64(byteCount),
-		EgressByteCount:  newu64(byteCount),
+		EgressPacketCount:  newu64(packetCount),
+		IngressPacketCount: newu64(packetCount),
+		EgressByteCount:    newu64(byteCount),
+		IngressByteCount:   newu64(byteCount),
 	}
 
 	interpolateCounts(r)
@@ -35,7 +36,10 @@ func TestInterpolateCounts(t *testing.T) {
 		apply  = func(v uint64) uint64 { return uint64(factor * float64(v)) }
 		emd    = r.Endpoint.EdgeMetadatas[edgeID]
 	)
-	if want, have := apply(packetCount), (*emd.PacketCount); want != have {
+	if want, have := apply(packetCount), (*emd.EgressPacketCount); want != have {
+		t.Errorf("want %d packets, have %d", want, have)
+	}
+	if want, have := apply(packetCount), (*emd.IngressPacketCount); want != have {
 		t.Errorf("want %d packets, have %d", want, have)
 	}
 	if want, have := apply(byteCount), (*emd.EgressByteCount); want != have {

probe/sniff/sniffer_test.go

@@ -72,8 +72,8 @@ func TestMerge(t *testing.T) {
 		},
 		EdgeMetadatas: report.EdgeMetadatas{
 			report.MakeEdgeID(srcEndpointNodeID, dstEndpointNodeID): report.EdgeMetadata{
-				PacketCount:     newu64(1),
-				EgressByteCount: newu64(256),
+				EgressPacketCount: newu64(1),
+				EgressByteCount:   newu64(256),
 			},
 		},
 		NodeMetadatas: report.NodeMetadatas{
@@ -95,8 +95,8 @@ func TestMerge(t *testing.T) {
 		},
 		EdgeMetadatas: report.EdgeMetadatas{
 			report.MakeEdgeID(srcAddressNodeID, dstAddressNodeID): report.EdgeMetadata{
-				PacketCount:     newu64(1),
-				EgressByteCount: newu64(512),
+				EgressPacketCount: newu64(1),
+				EgressByteCount:   newu64(512),
 			},
 		},
 		NodeMetadatas: report.NodeMetadatas{