Use the stack RNG everywhere

...except in tests.

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

PiperOrigin-RevId: 376070666

5 files changed, 15 insertions, 32 deletions

diff --git a/pkg/tcpip/transport/tcp/accept.go b/pkg/tcpip/transport/tcp/accept.go
index db75228a1..2c65b737d 100644
--- a/pkg/tcpip/transport/tcp/accept.go
+++ b/pkg/tcpip/transport/tcp/accept.go
@@ -591,7 +591,7 @@ func (e *endpoint) handleListenSegment(ctx *listenContext, s *segment) tcpip.Err
 		synOpts := header.TCPSynOptions{
 			WS:    -1,
 			TS:    opts.TS,
-			TSVal: tcpTimeStamp(e.stack.Clock().NowMonotonic(), timeStampOffset()),
+			TSVal: tcpTimeStamp(e.stack.Clock().NowMonotonic(), timeStampOffset(e.stack.Rand())),
 			TSEcr: opts.TSVal,
 			MSS:   calculateAdvertisedMSS(e.userMSS, route),
 		}
diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go
index 08849d0cc..570e5081c 100644
--- a/pkg/tcpip/transport/tcp/connect.go
+++ b/pkg/tcpip/transport/tcp/connect.go
@@ -19,7 +19,6 @@ import (
 	"math"
 	"time"
 
-	"gvisor.dev/gvisor/pkg/rand"
 	"gvisor.dev/gvisor/pkg/sleep"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -147,11 +146,6 @@ func FindWndScale(wnd seqnum.Size) int {
 // resetState resets the state of the handshake object such that it becomes
 // ready for a new 3-way handshake.
 func (h *handshake) resetState() {
-	b := make([]byte, 4)
-	if _, err := rand.Read(b); err != nil {
-		panic(err)
-	}
-
 	h.state = handshakeSynSent
 	h.flags = header.TCPFlagSyn
 	h.ackNum = 0
diff --git a/pkg/tcpip/transport/tcp/dispatcher.go b/pkg/tcpip/transport/tcp/dispatcher.go
index 5963a169c..dff7cb89c 100644
--- a/pkg/tcpip/transport/tcp/dispatcher.go
+++ b/pkg/tcpip/transport/tcp/dispatcher.go
@@ -16,8 +16,8 @@ package tcp
 
 import (
 	"encoding/binary"
+	"math/rand"
 
-	"gvisor.dev/gvisor/pkg/rand"
 	"gvisor.dev/gvisor/pkg/sleep"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -142,15 +142,16 @@ func (p *processor) start(wg *sync.WaitGroup) {
 // in-order.
 type dispatcher struct {
 	processors []processor
-	seed       uint32
-	wg         sync.WaitGroup
+	// seed is a random secret for a jenkins hash.
+	seed uint32
+	wg   sync.WaitGroup
 }
 
-func (d *dispatcher) init(nProcessors int) {
+func (d *dispatcher) init(rng *rand.Rand, nProcessors int) {
 	d.close()
 	d.wait()
 	d.processors = make([]processor, nProcessors)
-	d.seed = generateRandUint32()
+	d.seed = rng.Uint32()
 	for i := range d.processors {
 		p := &d.processors[i]
 		p.sleeper.AddWaker(&p.newEndpointWaker, newEndpointWaker)
@@ -212,14 +213,6 @@ func (d *dispatcher) queuePacket(stackEP stack.TransportEndpoint, id stack.Trans
 	d.selectProcessor(id).queueEndpoint(ep)
 }
 
-func generateRandUint32() uint32 {
-	b := make([]byte, 4)
-	if _, err := rand.Read(b); err != nil {
-		panic(err)
-	}
-	return binary.LittleEndian.Uint32(b)
-}
-
 func (d *dispatcher) selectProcessor(id stack.TransportEndpointID) *processor {
 	var payload [4]byte
 	binary.LittleEndian.PutUint16(payload[0:], id.LocalPort)
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index d44f480ab..a27e2110b 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -20,12 +20,12 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"math/rand"
 	"runtime"
 	"strings"
 	"sync/atomic"
 	"time"
 
-	"gvisor.dev/gvisor/pkg/rand"
 	"gvisor.dev/gvisor/pkg/sleep"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -882,7 +882,7 @@ func newEndpoint(s *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQue
 	}
 
 	e.segmentQueue.ep = e
-	e.TSOffset = timeStampOffset()
+	e.TSOffset = timeStampOffset(e.stack.Rand())
 	e.acceptCond = sync.NewCond(&e.acceptMu)
 	e.keepalive.timer.init(e.stack.Clock(), &e.keepalive.waker)
 
@@ -2215,7 +2215,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) tcp
 				BindToDevice: bindToDevice,
 				Dest:         addr,
 			}
-			if _, err := e.stack.ReservePort(portRes, nil /* testPort */); err != nil {
+			if _, err := e.stack.ReservePort(e.stack.Rand(), portRes, nil /* testPort */); err != nil {
 				if _, ok := err.(*tcpip.ErrPortInUse); !ok || !reuse {
 					return false, nil
 				}
@@ -2262,7 +2262,7 @@ func (e *endpoint) connect(addr tcpip.FullAddress, handshake bool, run bool) tcp
 					BindToDevice: bindToDevice,
 					Dest:         addr,
 				}
-				if _, err := e.stack.ReservePort(portRes, nil /* testPort */); err != nil {
+				if _, err := e.stack.ReservePort(e.stack.Rand(), portRes, nil /* testPort */); err != nil {
 					return false, nil
 				}
 			}
@@ -2598,7 +2598,7 @@ func (e *endpoint) bindLocked(addr tcpip.FullAddress) (err tcpip.Error) {
 		BindToDevice: bindToDevice,
 		Dest:         tcpip.FullAddress{},
 	}
-	port, err := e.stack.ReservePort(portRes, func(p uint16) (bool, tcpip.Error) {
+	port, err := e.stack.ReservePort(e.stack.Rand(), portRes, func(p uint16) (bool, tcpip.Error) {
 		id := e.TransportEndpointInfo.ID
 		id.LocalPort = p
 		// CheckRegisterTransportEndpoint should only return an error if there is a
@@ -2878,11 +2878,7 @@ func tcpTimeStamp(curTime tcpip.MonotonicTime, offset uint32) uint32 {
 
 // timeStampOffset returns a randomized timestamp offset to be used when sending
 // timestamp values in a timestamp option for a TCP segment.
-func timeStampOffset() uint32 {
-	b := make([]byte, 4)
-	if _, err := rand.Read(b); err != nil {
-		panic(err)
-	}
+func timeStampOffset(rng *rand.Rand) uint32 {
 	// Initialize a random tsOffset that will be added to the recentTS
 	// everytime the timestamp is sent when the Timestamp option is enabled.
 	//
@@ -2892,7 +2888,7 @@ func timeStampOffset() uint32 {
 	// NOTE: This is not completely to spec as normally this should be
 	// initialized in a manner analogous to how sequence numbers are
 	// randomized per connection basis. But for now this is sufficient.
-	return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24
+	return rng.Uint32()
 }
 
 // maybeEnableSACKPermitted marks the SACKPermitted option enabled for this endpoint
diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index 7c38ad480..2fc282e73 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -481,6 +481,6 @@ func NewProtocol(s *stack.Stack) stack.TransportProtocol {
 		// TODO(gvisor.dev/issue/5243): Set recovery to tcpip.TCPRACKLossDetection.
 		recovery: 0,
 	}
-	p.dispatcher.init(runtime.GOMAXPROCS(0))
+	p.dispatcher.init(s.Rand(), runtime.GOMAXPROCS(0))
 	return &p
 }