Fix up conntrack UTs; move to timeshim.

bpf/bpf.go

@@ -2220,13 +2220,3 @@ func SupportsBPFDataplane() error {
 
 	return nil
 }
-
-// KTimeNanos returns a nanosecond timestamp that is comparable with the ones generated by BPF.
-func KTimeNanos() int64 {
-	var ts unix.Timespec
-	err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &ts)
-	if err != nil {
-		log.WithError(err).Panic("Failed to read system clock")
-	}
-	return ts.Nano()
-}

bpf/bpf_syscall.go

@@ -598,3 +598,13 @@ func (m *MapIterator) Close() error {
 
 	return nil
 }
+
+// KTimeNanos returns a nanosecond timestamp that is comparable with the ones generated by BPF.
+func KTimeNanos() int64 {
+	var ts unix.Timespec
+	err := unix.ClockGettime(unix.CLOCK_MONOTONIC, &ts)
+	if err != nil {
+		log.WithError(err).Panic("Failed to read system clock")
+	}
+	return ts.Nano()
+}

bpf/bpf_syscall_stub.go

@@ -78,3 +78,7 @@ func (m *MapIterator) Next() (k, v []byte, err error) {
 func (m *MapIterator) Close() error {
 	return nil
 }
+
+func KTimeNanos() int64 {
+	panic("BPF syscall stub")
+}

bpf/conntrack/cleanup.go

@@ -21,6 +21,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/projectcalico/felix/bpf"
+	"github.com/projectcalico/felix/timeshim"
 )
 
 type Timeouts struct {
@@ -133,7 +134,7 @@ func (s *Scanner) get(k Key) (Value, error) {
 type LivenessScanner struct {
 	timeouts Timeouts
 	dsr      bool
-	NowNanos func() int64
+	time     timeshim.Interface
 
 	// goTimeOfLastKTimeLookup is the go timestamp of the last time we looked up the kernel time.
 	// We cache the kernel time because it's expensive to look up (vs looking up a go timestamp which uses vdso).
@@ -142,18 +143,30 @@ type LivenessScanner struct {
 	cachedKTime int64
 }
 
-func NewLivenessScanner(timeouts Timeouts, dsr bool) *LivenessScanner {
-	return &LivenessScanner{
+func NewLivenessScanner(timeouts Timeouts, dsr bool, opts ...LivenessScannerOpt) *LivenessScanner {
+	ls := &LivenessScanner{
 		timeouts: timeouts,
 		dsr:      dsr,
-		NowNanos: bpf.KTimeNanos,
+		time:     timeshim.RealTime(),
+	}
+	for _, opt := range opts {
+		opt(ls)
+	}
+	return ls
+}
+
+type LivenessScannerOpt func(ls *LivenessScanner)
+
+func WithTimeShim(shim timeshim.Interface) LivenessScannerOpt {
+	return func(ls *LivenessScanner) {
+		ls.time = shim
 	}
 }
 
 func (l *LivenessScanner) ScanEntry(ctKey Key, ctVal Value, get EntryGet) ScanVerdict {
-	if l.cachedKTime == 0 || time.Since(l.goTimeOfLastKTimeLookup) > time.Second {
-		l.cachedKTime = l.NowNanos()
-		l.goTimeOfLastKTimeLookup = time.Now()
+	if l.cachedKTime == 0 || l.time.Since(l.goTimeOfLastKTimeLookup) > time.Second {
+		l.cachedKTime = l.time.KTimeNanos()
+		l.goTimeOfLastKTimeLookup =  l.time.Now()
 	}
 	now := l.cachedKTime
 

bpf/conntrack/conntrack_suite_test.go

@@ -33,7 +33,7 @@ func init() {
 	logrus.SetFormatter(&logutils.Formatter{})
 }
 
-func TestCalculationGraph(t *testing.T) {
+func TestBPFConntrack(t *testing.T) {
 	RegisterFailHandler(Fail)
 	junitReporter := reporters.NewJUnitReporter("../../report/bpf_conntrack_suite.xml")
 	RunSpecsWithDefaultAndCustomReporters(t, "BPF Conntrack Suite", []Reporter{junitReporter})

bpf/conntrack/conntrack_test.go

@@ -21,6 +21,7 @@ import (
 	"time"
 
 	"github.com/projectcalico/felix/bpf"
+	"github.com/projectcalico/felix/timeshim/mocktime"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/ginkgo/extensions/table"
@@ -30,7 +31,7 @@ import (
 	"github.com/projectcalico/felix/bpf/mock"
 )
 
-const now = 1000 * time.Hour
+var now = mocktime.StartKTime
 
 var (
 	ip1     = net.ParseIP("10.0.0.1")
@@ -73,13 +74,13 @@ var _ = Describe("BPF Conntrack LivenessCalculator", func() {
 	var lc *conntrack.LivenessScanner
 	var scanner *conntrack.Scanner
 	var ctMap *mock.Map
+	var mockTime *mocktime.MockTime
 
 	BeforeEach(func() {
+		mockTime = mocktime.New()
+		Expect(mockTime.KTimeNanos()).To(BeNumerically("==",now))
 		ctMap = mock.NewMockMap(conntrack.MapParams)
-		lc = conntrack.NewLivenessScanner(timeouts, false)
-		lc.NowNanos = func() int64 {
-			return int64(now)
-		}
+		lc = conntrack.NewLivenessScanner(timeouts, false, conntrack.WithTimeShim(mockTime))
 		scanner = conntrack.NewScanner(ctMap, lc.ScanEntry)
 	})
 
@@ -119,9 +120,7 @@ var _ = Describe("BPF Conntrack LivenessCalculator", func() {
 			By("always deleting the entry if we fast-forward time")
 			err = ctMap.Update(key.AsBytes(), entry[:])
 			Expect(err).NotTo(HaveOccurred())
-			lc.NowNanos = func() int64 {
-				return int64(now + 2*time.Hour)
-			}
+			mockTime.IncrementTime(2*time.Hour)
 			scanner.Scan()
 			_, err = ctMap.Get(key.AsBytes())
 			Expect(bpf.IsNotExists(err)).To(BeTrue(), "Scan() should have cleaned up entry")

timeshim/mocktime/mocktime.go

@@ -24,11 +24,13 @@ import (
 	"github.com/projectcalico/felix/timeshim"
 )
 
-var startTime, _ = time.Parse(time.RFC3339, "2006-01-02T15:04:05Z")
+var StartTime, _ = time.Parse(time.RFC3339, "2006-01-02T15:04:05Z")
+var StartKTime = 1000 * time.Hour
+var KTimeEpoch = StartTime.Add(-StartKTime)
 
 func New() *MockTime {
 	return &MockTime{
-		currentTime: startTime,
+		currentTime: StartTime,
 	}
 }
 
@@ -125,6 +127,13 @@ func (m *MockTime) Now() time.Time {
 	return t
 }
 
+func (m *MockTime) KTimeNanos() int64 {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	// Kernel time isn't necessarily coupled to the same epoch so use a different one.
+	return int64(m.currentTime.Sub(KTimeEpoch))
+}
+
 func (m *MockTime) Since(t time.Time) time.Duration {
 	return m.Now().Sub(t)
 }
@@ -153,7 +162,7 @@ func (m *MockTime) incrementTimeLockHeld(t time.Duration) {
 	}
 
 	m.currentTime = m.currentTime.Add(t)
-	logrus.WithField("increment", t).WithField("t", m.currentTime.Sub(startTime)).Info("Incrementing time")
+	logrus.WithField("increment", t).WithField("t", m.currentTime.Sub(StartTime)).Info("Incrementing time")
 
 	if len(m.timers) == 0 {
 		return

timeshim/time.go

@@ -16,6 +16,8 @@ package timeshim
 
 import (
 	"time"
+
+	"github.com/projectcalico/felix/bpf"
 )
 
 // Time is our shim interface to the time package.
@@ -25,6 +27,7 @@ type Interface interface {
 	Until(t time.Time) time.Duration
 	After(t time.Duration) <-chan time.Time
 	NewTimer(d Duration) Timer
+	KTimeNanos() int64
 }
 
 type Time = time.Time
@@ -79,3 +82,7 @@ func (realTime) Now() time.Time {
 func (realTime) Since(t time.Time) time.Duration {
 	return time.Since(t)
 }
+
+func (realTime) KTimeNanos() int64 {
+	return bpf.KTimeNanos()
+}