add a test to exercise more code paths

schema/pcap.go

@@ -17,10 +17,10 @@ type AlphaFields struct {
 	SynAckTime        time.Time `bigquery:"syn_ack_time" json:"syn_ack_time"`
 	Packets           int64     `bigquery:"packets" json:"packets"`
 	OptionCounts      []int64   `bigquery:"option_counts" json:"option_counts"`
-	FirstECECount     uint64    `bigquery:"first_ece_count" json:"first_ece_count"`
-	SecondECECount    uint64    `bigquery:"second_ece_count" json:"second_ece_count"`
-	FirstRetransmits  uint64    `bigquery:"first_retransmits" json:"first_retransmits"`
-	SecondRetransmits uint64    `bigquery:"second_retransmits" json:"second_retransmits"`
+	FirstECECount     int64     `bigquery:"first_ece_count" json:"first_ece_count"`
+	SecondECECount    int64     `bigquery:"second_ece_count" json:"second_ece_count"`
+	FirstRetransmits  int64     `bigquery:"first_retransmits" json:"first_retransmits"`
+	SecondRetransmits int64     `bigquery:"second_retransmits" json:"second_retransmits"`
 	Sacks             int64     `bigquery:"sacks" json:"sacks"`
 	TotalSrcSeq       int64     `bigquery:"total_src_seq" json:"total_src_seq"`
 	TotalDstSeq       int64     `bigquery:"total_dst_seq" json:"total_dst_seq"`

tcp/tcp.go

@@ -44,13 +44,14 @@ type sackBlock struct {
 }
 
 type Tracker struct {
-	initialized bool
-	errors      uint32 // Number of errors encountered while parsing
-	packets     uint32 // Number of calls to Seq function
-	seq         uint32 // The last sequence number observed, not counting retransmits
-	synFin      uint32 // zero, one or two, depending on whether SYN and FIN were sent
-	sent        uint64 // actual bytes sent, including retransmits, but not SYN or FIN
-	retransmits uint64 // bytes retransmitted
+	initialized    bool
+	errors         uint32 // Number of errors encountered while parsing
+	packets        uint32 // Number of calls to Seq function
+	seq            uint32 // The last sequence number observed, not counting retransmits
+	synFin         uint32 // zero, one or two, depending on whether SYN and FIN were sent
+	sent           uint64 // actual bytes sent, including retransmits, but not SYN or FIN
+	retransmits    uint64 // bytes retransmitted
+	retransPackets uint32 // number of retransmitted packets
 
 	sendUNA  uint32 // greatest observed ack
 	acks     uint32 // number of acks (from other side)
@@ -119,6 +120,7 @@ func (t *Tracker) Seq(clock uint32, length uint16, synFin bool) (int32, bool) {
 	if delta < 0 {
 		// DO NOT update w.seq or w.lastDataLength, as this is a retransmit
 		t.sent += uint64(length)
+		t.retransPackets++
 		t.retransmits += uint64(length)
 		return inflight, true
 	}
@@ -269,9 +271,13 @@ func (s *state) Option(port layers.TCPPort, opt layers.TCPOption) {
 		}
 	case layers.TCPOptionKindTimestamps:
 	case layers.TCPOptionKindWindowScale:
-		// TODO should this change after initialization?
-		sparse.Printf("%v WindowScale change %d -> %d\n", port, s.WindowScale, opt.OptionData[0])
-		s.WindowScale = opt.OptionData[0]
+		if len(opt.OptionData) != 1 {
+			info.Println("Invalid WindowScale option length", len(opt.OptionData))
+		} else {
+			// TODO should this change after initialization?
+			sparse.Printf("%v WindowScale change %d -> %d\n", port, s.WindowScale, opt.OptionData[0])
+			s.WindowScale = opt.OptionData[0]
+		}
 	default:
 	}
 }
@@ -465,10 +471,10 @@ func (p *Parser) Parse(data []byte) (*schema.AlphaFields, error) {
 	info.Printf("%20s: %v\n", p.LeftState.SrcPort, p.LeftState.SeqTracker.Summary())
 	info.Printf("%20s: %v\n", p.RightState.SrcPort, p.RightState.SeqTracker.Summary())
 
-	alpha.FirstECECount = p.LeftState.ECECount
-	alpha.SecondECECount = p.RightState.ECECount
-	alpha.FirstRetransmits = p.LeftState.SeqTracker.retransmits
-	alpha.SecondRetransmits = p.RightState.SeqTracker.retransmits
+	alpha.FirstECECount = int64(p.LeftState.ECECount)
+	alpha.SecondECECount = int64(p.RightState.ECECount)
+	alpha.FirstRetransmits = int64(p.LeftState.SeqTracker.retransPackets)
+	alpha.SecondRetransmits = int64(p.RightState.SeqTracker.retransPackets)
 	// TODO update these names
 	alpha.TotalSrcSeq = int64(p.LeftState.SeqTracker.ByteCount())
 	alpha.TotalDstSeq = int64(p.RightState.SeqTracker.ByteCount())

tcp/tcp_test.go

@@ -1,6 +1,8 @@
 package tcp_test
 
 import (
+	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/m-lab/etl/tcp"
@@ -89,3 +91,33 @@ func TestTracker_SendNext(t *testing.T) {
 			})
 		}*/
 }
+
+// TestParse exercises a lot of code, on the ipv4 path.  It only checks
+// some basic stats, which are assumed to be correct, but not inspected.
+func TestParse(t *testing.T) {
+	f, err := os.Open("testfiles/ndt-nnwk2_1611335823_00000000000C2DFE.pcap")
+	if err != nil {
+		t.Fatal(err)
+	}
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+	tcp := tcp.Parser{}
+	summary, err := tcp.Parse(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if summary.Packets != 336 {
+		t.Errorf("Packets = %v, want %v", summary.Packets, 336)
+	}
+	if summary.FirstRetransmits != 11 {
+		t.Errorf("FirstRetransmits = %v, want %v", summary.FirstRetransmits, 11)
+	}
+	if summary.SecondRetransmits != 8 {
+		t.Errorf("SecondRetransmits = %v, want %v", summary.SecondRetransmits, 8)
+	}
+	if summary.TruncatedPackets != 0 {
+		t.Errorf("TruncatedPackets = %v, want %v", summary.TruncatedPackets, 0)
+	}
+}