Use the stack RNG everywhere

...except in tests.

Note this replaces some uses of a cryptographic RNG with a plain RNG.

PiperOrigin-RevId: 376070666

2 files changed, 10 insertions, 7 deletions

diff --git a/pkg/tcpip/ports/ports.go b/pkg/tcpip/ports/ports.go
index b5b013b64..854d6a6ba 100644
--- a/pkg/tcpip/ports/ports.go
+++ b/pkg/tcpip/ports/ports.go
@@ -101,7 +101,7 @@ func (dc destToCounter) intersectionFlags(res Reservation) (BitFlags, int) {
 		// Wildcard destinations affect all destinations for TupleOnly.
 		if dest.addr == anyIPAddress || res.Dest.Addr == anyIPAddress {
 			// Only bitwise and the TupleOnlyFlag.
-			intersection &= ((^TupleOnlyFlag) | counter.SharedFlags())
+			intersection &= (^TupleOnlyFlag) | counter.SharedFlags()
 			count++
 		}
 	}
@@ -238,13 +238,13 @@ type PortTester func(port uint16) (good bool, err tcpip.Error)
 // possible ephemeral ports, allowing the caller to decide whether a given port
 // is suitable for its needs, and stopping when a port is found or an error
 // occurs.
-func (pm *PortManager) PickEphemeralPort(testPort PortTester) (port uint16, err tcpip.Error) {
+func (pm *PortManager) PickEphemeralPort(rng *rand.Rand, testPort PortTester) (port uint16, err tcpip.Error) {
 	pm.ephemeralMu.RLock()
 	firstEphemeral := pm.firstEphemeral
 	numEphemeral := pm.numEphemeral
 	pm.ephemeralMu.RUnlock()
 
-	offset := uint32(rand.Int31n(int32(numEphemeral)))
+	offset := uint32(rng.Int31n(int32(numEphemeral)))
 	return pickEphemeralPort(offset, firstEphemeral, numEphemeral, testPort)
 }
 
@@ -303,7 +303,7 @@ func pickEphemeralPort(offset uint32, first, count uint16, testPort PortTester)
 // An optional PortTester can be passed in which if provided will be used to
 // test if the picked port can be used. The function should return true if the
 // port is safe to use, false otherwise.
-func (pm *PortManager) ReservePort(res Reservation, testPort PortTester) (reservedPort uint16, err tcpip.Error) {
+func (pm *PortManager) ReservePort(rng *rand.Rand, res Reservation, testPort PortTester) (reservedPort uint16, err tcpip.Error) {
 	pm.mu.Lock()
 	defer pm.mu.Unlock()
 
@@ -328,7 +328,7 @@ func (pm *PortManager) ReservePort(res Reservation, testPort PortTester) (reserv
 	}
 
 	// A port wasn't specified, so try to find one.
-	return pm.PickEphemeralPort(func(p uint16) (bool, tcpip.Error) {
+	return pm.PickEphemeralPort(rng, func(p uint16) (bool, tcpip.Error) {
 		res.Port = p
 		if !pm.reserveSpecificPortLocked(res) {
 			return false, nil
diff --git a/pkg/tcpip/ports/ports_test.go b/pkg/tcpip/ports/ports_test.go
index 6c4fb8c68..a91b130df 100644
--- a/pkg/tcpip/ports/ports_test.go
+++ b/pkg/tcpip/ports/ports_test.go
@@ -18,6 +18,7 @@ import (
 	"math"
 	"math/rand"
 	"testing"
+	"time"
 
 	"github.com/google/go-cmp/cmp"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -331,6 +332,7 @@ func TestPortReservation(t *testing.T) {
 		t.Run(test.tname, func(t *testing.T) {
 			pm := NewPortManager()
 			net := []tcpip.NetworkProtocolNumber{fakeNetworkNumber}
+			rng := rand.New(rand.NewSource(time.Now().UnixNano()))
 
 			for _, test := range test.actions {
 				first, _ := pm.PortRange()
@@ -356,7 +358,7 @@ func TestPortReservation(t *testing.T) {
 					BindToDevice: test.device,
 					Dest:         test.dest,
 				}
-				gotPort, err := pm.ReservePort(portRes, nil /* testPort */)
+				gotPort, err := pm.ReservePort(rng, portRes, nil /* testPort */)
 				if diff := cmp.Diff(test.want, err); diff != "" {
 					t.Fatalf("unexpected error from ReservePort(%+v, _), (-want, +got):\n%s", portRes, diff)
 				}
@@ -417,10 +419,11 @@ func TestPickEphemeralPort(t *testing.T) {
 	} {
 		t.Run(test.name, func(t *testing.T) {
 			pm := NewPortManager()
+			rng := rand.New(rand.NewSource(time.Now().UnixNano()))
 			if err := pm.SetPortRange(firstEphemeral, firstEphemeral+numEphemeralPorts); err != nil {
 				t.Fatalf("failed to set ephemeral port range: %s", err)
 			}
-			port, err := pm.PickEphemeralPort(test.f)
+			port, err := pm.PickEphemeralPort(rng, test.f)
 			if diff := cmp.Diff(test.wantErr, err); diff != "" {
 				t.Fatalf("unexpected error from PickEphemeralPort(..), (-want, +got):\n%s", diff)
 			}