Use the stack RNG

Remove redundant interface.

PiperOrigin-RevId: 375756254

2 files changed, 11 insertions, 13 deletions

diff --git a/pkg/tcpip/stack/nud.go b/pkg/tcpip/stack/nud.go
index 02f905351..dac94cbe4 100644
--- a/pkg/tcpip/stack/nud.go
+++ b/pkg/tcpip/stack/nud.go
@@ -16,6 +16,7 @@ package stack
 
 import (
 	"math"
+	"math/rand"
 	"sync"
 	"time"
 
@@ -313,15 +314,9 @@ func calcMaxRandomFactor(minRandomFactor float32) float32 {
 	return defaultMaxRandomFactor
 }
 
-// A Rand is a source of random numbers.
-type Rand interface {
-	// Float32 returns, as a float32, a pseudo-random number in [0.0,1.0).
-	Float32() float32
-}
-
 // NUDState stores states needed for calculating reachable time.
 type NUDState struct {
-	rng Rand
+	rng *rand.Rand
 
 	mu struct {
 		sync.RWMutex
@@ -342,7 +337,7 @@ type NUDState struct {
 
 // NewNUDState returns new NUDState using c as configuration and the specified
 // random number generator for use in recomputing ReachableTime.
-func NewNUDState(c NUDConfigurations, rng Rand) *NUDState {
+func NewNUDState(c NUDConfigurations, rng *rand.Rand) *NUDState {
 	s := &NUDState{
 		rng: rng,
 	}
diff --git a/pkg/tcpip/stack/nud_test.go b/pkg/tcpip/stack/nud_test.go
index 6ba97d626..d85213fba 100644
--- a/pkg/tcpip/stack/nud_test.go
+++ b/pkg/tcpip/stack/nud_test.go
@@ -16,6 +16,7 @@ package stack_test
 
 import (
 	"math"
+	"math/rand"
 	"testing"
 	"time"
 
@@ -46,12 +47,14 @@ type fakeRand struct {
 	num float32
 }
 
-var _ stack.Rand = (*fakeRand)(nil)
+var _ rand.Source = (*fakeRand)(nil)
 
-func (f *fakeRand) Float32() float32 {
-	return f.num
+func (f *fakeRand) Int63() int64 {
+	return int64(f.num * float32(1<<63))
 }
 
+func (*fakeRand) Seed(int64) {}
+
 func TestNUDFunctions(t *testing.T) {
 	const nicID = 1
 
@@ -708,7 +711,7 @@ func TestNUDStateReachableTime(t *testing.T) {
 			rng := fakeRand{
 				num: defaultFakeRandomNum,
 			}
-			s := stack.NewNUDState(c, &rng)
+			s := stack.NewNUDState(c, rand.New(&rng))
 			if got, want := s.ReachableTime(), test.want; got != want {
 				t.Errorf("got ReachableTime = %q, want = %q", got, want)
 			}
@@ -780,7 +783,7 @@ func TestNUDStateRecomputeReachableTime(t *testing.T) {
 			rng := fakeRand{
 				num: defaultFakeRandomNum,
 			}
-			s := stack.NewNUDState(c, &rng)
+			s := stack.NewNUDState(c, rand.New(&rng))
 			old := s.ReachableTime()
 
 			if got, want := s.ReachableTime(), old; got != want {