Use opaque types to represent time

Introduce tcpip.MonotonicTime; replace int64 in tcpip.Clock method
returns with time.Time and MonotonicTime to improve type safety and
ensure that monotonic clock readings are never compared to wall clock
readings.

PiperOrigin-RevId: 375775907

4 files changed, 14 insertions, 14 deletions

diff --git a/pkg/tcpip/network/arp/arp_test.go b/pkg/tcpip/network/arp/arp_test.go
index f89b55561..3ca78490f 100644
--- a/pkg/tcpip/network/arp/arp_test.go
+++ b/pkg/tcpip/network/arp/arp_test.go
@@ -126,7 +126,7 @@ func (d *arpDispatcher) OnNeighborRemoved(nicID tcpip.NICID, entry stack.Neighbo
 func (d *arpDispatcher) waitForEvent(ctx context.Context, want eventInfo) error {
 	select {
 	case got := <-d.C:
-		if diff := cmp.Diff(want, got, cmp.AllowUnexported(got), cmpopts.IgnoreFields(stack.NeighborEntry{}, "UpdatedAtNanos")); diff != "" {
+		if diff := cmp.Diff(want, got, cmp.AllowUnexported(got), cmpopts.IgnoreFields(stack.NeighborEntry{}, "UpdatedAt")); diff != "" {
 			return fmt.Errorf("got invalid event (-want +got):\n%s", diff)
 		}
 	case <-ctx.Done():
diff --git a/pkg/tcpip/network/internal/fragmentation/fragmentation.go b/pkg/tcpip/network/internal/fragmentation/fragmentation.go
index 5168f5361..1ba4d0d36 100644
--- a/pkg/tcpip/network/internal/fragmentation/fragmentation.go
+++ b/pkg/tcpip/network/internal/fragmentation/fragmentation.go
@@ -251,7 +251,7 @@ func (f *Fragmentation) releaseReassemblersLocked() {
 			// The list is empty.
 			break
 		}
-		elapsed := time.Duration(now-r.creationTime) * time.Nanosecond
+		elapsed := now.Sub(r.createdAt)
 		if f.timeout > elapsed {
 			// If the oldest reassembler has not expired, schedule the release
 			// job so that this function is called back when it has expired.
diff --git a/pkg/tcpip/network/internal/fragmentation/reassembler.go b/pkg/tcpip/network/internal/fragmentation/reassembler.go
index 56b76a284..5b7e4b361 100644
--- a/pkg/tcpip/network/internal/fragmentation/reassembler.go
+++ b/pkg/tcpip/network/internal/fragmentation/reassembler.go
@@ -35,21 +35,21 @@ type hole struct {
 
 type reassembler struct {
 	reassemblerEntry
-	id           FragmentID
-	memSize      int
-	proto        uint8
-	mu           sync.Mutex
-	holes        []hole
-	filled       int
-	done         bool
-	creationTime int64
-	pkt          *stack.PacketBuffer
+	id        FragmentID
+	memSize   int
+	proto     uint8
+	mu        sync.Mutex
+	holes     []hole
+	filled    int
+	done      bool
+	createdAt tcpip.MonotonicTime
+	pkt       *stack.PacketBuffer
 }
 
 func newReassembler(id FragmentID, clock tcpip.Clock) *reassembler {
 	r := &reassembler{
-		id:           id,
-		creationTime: clock.NowMonotonic(),
+		id:        id,
+		createdAt: clock.NowMonotonic(),
 	}
 	r.holes = append(r.holes, hole{
 		first:  0,
diff --git a/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go b/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
index d22974b12..671dfbf32 100644
--- a/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
+++ b/pkg/tcpip/network/internal/ip/generic_multicast_protocol.go
@@ -611,7 +611,7 @@ func (g *GenericMulticastProtocolState) setDelayTimerForAddressRLocked(groupAddr
 	//   If a timer for any address is already running, it is reset to the new
 	//   random value only if the requested Maximum Response Delay is less than
 	//   the remaining value of the running timer.
-	now := time.Unix(0 /* seconds */, g.opts.Clock.NowNanoseconds())
+	now := g.opts.Clock.Now()
 	if info.state == delayingMember {
 		if info.delayedReportJobFiresAt.IsZero() {
 			panic(fmt.Sprintf("delayed report unscheduled while in the delaying member state; group = %s", groupAddress))