Remove detritus

- Unused constants
- Unused functions
- Unused arguments
- Unkeyed literals
- Unnecessary conversions

PiperOrigin-RevId: 375253464

9 files changed, 36 insertions, 44 deletions

diff --git a/pkg/tcpip/transport/tcp/dual_stack_test.go b/pkg/tcpip/transport/tcp/dual_stack_test.go
index f148d505d..5342aacfd 100644
--- a/pkg/tcpip/transport/tcp/dual_stack_test.go
+++ b/pkg/tcpip/transport/tcp/dual_stack_test.go
@@ -421,7 +421,7 @@ func testV4Accept(t *testing.T, c *context.Context) {
 	r.Reset(data)
 	nep.Write(&r, tcpip.WriteOptions{})
 	b = c.GetPacket()
-	tcp = header.TCP(header.IPv4(b).Payload())
+	tcp = header.IPv4(b).Payload()
 	if string(tcp.Payload()) != data {
 		t.Fatalf("Unexpected data: got %v, want %v", string(tcp.Payload()), data)
 	}
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index c6bf1fd98..fb7670adb 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -818,7 +818,7 @@ func newEndpoint(s *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQue
 		},
 		sndQueueInfo: sndQueueInfo{
 			TCPSndBufState: stack.TCPSndBufState{
-				SndMTU: int(math.MaxInt32),
+				SndMTU: math.MaxInt32,
 			},
 		},
 		waiterQueue: waiterQueue,
@@ -2748,7 +2748,7 @@ func (e *endpoint) updateSndBufferUsage(v int) {
 	// We only notify when there is half the sendBufferSize available after
 	// a full buffer event occurs. This ensures that we don't wake up
 	// writers to queue just 1-2 segments and go back to sleep.
-	notify = notify && e.sndQueueInfo.SndBufUsed < int(sendBufferSize)>>1
+	notify = notify && e.sndQueueInfo.SndBufUsed < sendBufferSize>>1
 	e.sndQueueInfo.sndQueueMu.Unlock()
 
 	if notify {
diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go
index a3d1aa1a3..d43e21426 100644
--- a/pkg/tcpip/transport/tcp/protocol.go
+++ b/pkg/tcpip/transport/tcp/protocol.go
@@ -401,7 +401,7 @@ func (p *protocol) Option(option tcpip.GettableTransportProtocolOption) tcpip.Er
 
 	case *tcpip.TCPTimeWaitReuseOption:
 		p.mu.RLock()
-		*v = tcpip.TCPTimeWaitReuseOption(p.timeWaitReuse)
+		*v = p.timeWaitReuse
 		p.mu.RUnlock()
 		return nil
 
diff --git a/pkg/tcpip/transport/tcp/rack.go b/pkg/tcpip/transport/tcp/rack.go
index 9e332dcf7..813a6dffd 100644
--- a/pkg/tcpip/transport/tcp/rack.go
+++ b/pkg/tcpip/transport/tcp/rack.go
@@ -279,7 +279,7 @@ func (s *sender) detectTLPRecovery(ack seqnum.Value, rcvdSeg *segment) {
 //   been observed RACK uses reo_wnd of zero during loss recovery, in order to
 //   retransmit quickly, or when the number of DUPACKs exceeds the classic
 //   DUPACKthreshold.
-func (rc *rackControl) updateRACKReorderWindow(ackSeg *segment) {
+func (rc *rackControl) updateRACKReorderWindow() {
 	dsackSeen := rc.DSACKSeen
 	snd := rc.snd
 
diff --git a/pkg/tcpip/transport/tcp/rcv.go b/pkg/tcpip/transport/tcp/rcv.go
index 133371455..4fd8a0624 100644
--- a/pkg/tcpip/transport/tcp/rcv.go
+++ b/pkg/tcpip/transport/tcp/rcv.go
@@ -137,9 +137,9 @@ func (r *receiver) getSendParams() (RcvNxt seqnum.Value, rcvWnd seqnum.Size) {
 	// rcvWUP       RcvNxt         RcvAcc          new RcvAcc
 	//               <=====curWnd ===>
 	//               <========= newWnd > curWnd ========= >
-	if r.RcvNxt.Add(seqnum.Size(curWnd)).LessThan(r.RcvNxt.Add(seqnum.Size(newWnd))) && toGrow {
+	if r.RcvNxt.Add(curWnd).LessThan(r.RcvNxt.Add(newWnd)) && toGrow {
 		// If the new window moves the right edge, then update RcvAcc.
-		r.RcvAcc = r.RcvNxt.Add(seqnum.Size(newWnd))
+		r.RcvAcc = r.RcvNxt.Add(newWnd)
 	} else {
 		if newWnd == 0 {
 			// newWnd is zero but we can't advertise a zero as it would cause window
diff --git a/pkg/tcpip/transport/tcp/segment.go b/pkg/tcpip/transport/tcp/segment.go
index 7e5ba6ef7..61754de29 100644
--- a/pkg/tcpip/transport/tcp/segment.go
+++ b/pkg/tcpip/transport/tcp/segment.go
@@ -243,7 +243,7 @@ func (s *segment) parse(skipChecksumValidation bool) bool {
 		return false
 	}
 
-	s.options = []byte(s.hdr[header.TCPMinimumSize:])
+	s.options = s.hdr[header.TCPMinimumSize:]
 	s.parsedOptions = header.ParseTCPOptions(s.options)
 	if skipChecksumValidation {
 		s.csumValid = true
@@ -262,5 +262,5 @@ func (s *segment) parse(skipChecksumValidation bool) bool {
 
 // sackBlock returns a header.SACKBlock that represents this segment.
 func (s *segment) sackBlock() header.SACKBlock {
-	return header.SACKBlock{s.sequenceNumber, s.sequenceNumber.Add(s.logicalLen())}
+	return header.SACKBlock{Start: s.sequenceNumber, End: s.sequenceNumber.Add(s.logicalLen())}
 }
diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go
index f43e86677..6b7293755 100644
--- a/pkg/tcpip/transport/tcp/snd.go
+++ b/pkg/tcpip/transport/tcp/snd.go
@@ -616,7 +616,7 @@ func (s *sender) NextSeg(nextSegHint *segment) (nextSeg, hint *segment, rescueRt
 		//     'S2' that meets the following 3 criteria for determinig
 		//     loss, the sequence range of one segment of up to SMSS
 		//     octects starting with S2 MUST be returned.
-		if !s.ep.scoreboard.IsSACKED(header.SACKBlock{segSeq, segSeq.Add(1)}) {
+		if !s.ep.scoreboard.IsSACKED(header.SACKBlock{Start: segSeq, End: segSeq.Add(1)}) {
 			// NextSeg():
 			//
 			//    (1.a) S2 is greater than HighRxt
@@ -1024,7 +1024,7 @@ func (s *sender) SetPipe() {
 			if segEnd.LessThan(endSeq) {
 				endSeq = segEnd
 			}
-			sb := header.SACKBlock{startSeq, endSeq}
+			sb := header.SACKBlock{Start: startSeq, End: endSeq}
 			// SetPipe():
 			//
 			// After initializing pipe to zero, the following steps are
@@ -1455,7 +1455,7 @@ func (s *sender) handleRcvdSegment(rcvdSeg *segment) {
 		// See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-7.2
 		// * Upon receiving an ACK:
 		// * Step 4: Update RACK reordering window
-		s.rc.updateRACKReorderWindow(rcvdSeg)
+		s.rc.updateRACKReorderWindow()
 
 		// After the reorder window is calculated, detect any loss by checking
 		// if the time elapsed after the segments are sent is greater than the
diff --git a/pkg/tcpip/transport/tcp/tcp_rack_test.go b/pkg/tcpip/transport/tcp/tcp_rack_test.go
index c58361bc1..29af87b7d 100644
--- a/pkg/tcpip/transport/tcp/tcp_rack_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_rack_test.go
@@ -38,7 +38,7 @@ const (
 
 func setStackRACKPermitted(t *testing.T, c *context.Context) {
 	t.Helper()
-	opt := tcpip.TCPRecovery(tcpip.TCPRACKLossDetection)
+	opt := tcpip.TCPRACKLossDetection
 	if err := c.Stack().SetTransportProtocolOption(header.TCPProtocolNumber, &opt); err != nil {
 		t.Fatalf("c.s.SetTransportProtocolOption(%d, &%v(%v)): %s", header.TCPProtocolNumber, opt, opt, err)
 	}
diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go
index 9916182e3..e7ede7662 100644
--- a/pkg/tcpip/transport/tcp/tcp_test.go
+++ b/pkg/tcpip/transport/tcp/tcp_test.go
@@ -4259,7 +4259,7 @@ func TestReceivedInvalidSegmentCountIncrement(t *testing.T) {
 		SrcPort: context.TestPort,
 		DstPort: c.Port,
 		Flags:   header.TCPFlagAck,
-		SeqNum:  seqnum.Value(iss),
+		SeqNum:  iss,
 		AckNum:  c.IRS.Add(1),
 		RcvWnd:  30000,
 	})
@@ -5335,7 +5335,7 @@ func TestKeepalive(t *testing.T) {
 		checker.IPv4(t, b,
 			checker.TCP(
 				checker.DstPort(context.TestPort),
-				checker.TCPSeqNum(uint32(next-1)),
+				checker.TCPSeqNum(next-1),
 				checker.TCPAckNum(uint32(iss)),
 				checker.TCPFlags(header.TCPFlagAck),
 			),
@@ -5360,12 +5360,7 @@ func TestKeepalive(t *testing.T) {
 	})
 
 	checker.IPv4(t, c.GetPacket(),
-		checker.TCP(
-			checker.DstPort(context.TestPort),
-			checker.TCPSeqNum(uint32(next)),
-			checker.TCPAckNum(uint32(0)),
-			checker.TCPFlags(header.TCPFlagRst),
-		),
+		checker.TCP(checker.DstPort(context.TestPort), checker.TCPSeqNum(next), checker.TCPAckNum(uint32(0)), checker.TCPFlags(header.TCPFlagRst)),
 	)
 
 	if got := c.Stack().Stats().TCP.EstablishedTimedout.Value(); got != 1 {
@@ -5507,7 +5502,7 @@ func TestListenBacklogFull(t *testing.T) {
 	// Now execute send one more SYN. The stack should not respond as the backlog
 	// is full at this point.
 	c.SendPacket(nil, &context.Headers{
-		SrcPort: context.TestPort + uint16(lastPortOffset),
+		SrcPort: context.TestPort + lastPortOffset,
 		DstPort: context.StackPort,
 		Flags:   header.TCPFlagSyn,
 		SeqNum:  seqnum.Value(context.TestInitialSequenceNumber),
@@ -5884,7 +5879,7 @@ func TestListenSynRcvdQueueFull(t *testing.T) {
 	r.Reset(data)
 	newEP.Write(&r, tcpip.WriteOptions{})
 	pkt := c.GetPacket()
-	tcp = header.TCP(header.IPv4(pkt).Payload())
+	tcp = header.IPv4(pkt).Payload()
 	if string(tcp.Payload()) != data {
 		t.Fatalf("unexpected data: got %s, want %s", string(tcp.Payload()), data)
 	}
@@ -6118,7 +6113,7 @@ func TestSynRcvdBadSeqNumber(t *testing.T) {
 	}
 
 	pkt := c.GetPacket()
-	tcpHdr = header.TCP(header.IPv4(pkt).Payload())
+	tcpHdr = header.IPv4(pkt).Payload()
 	if string(tcpHdr.Payload()) != data {
 		t.Fatalf("unexpected data: got %s, want %s", string(tcpHdr.Payload()), data)
 	}
@@ -6375,7 +6370,7 @@ func TestReceiveBufferAutoTuningApplicationLimited(t *testing.T) {
 
 	// Allocate a large enough payload for the test.
 	payloadSize := receiveBufferSize * 2
-	b := make([]byte, int(payloadSize))
+	b := make([]byte, payloadSize)
 
 	worker := (c.EP).(interface {
 		StopWork()
@@ -6429,7 +6424,7 @@ func TestReceiveBufferAutoTuningApplicationLimited(t *testing.T) {
 	// ack, 1 for the non-zero window
 	p := c.GetPacket()
 	checker.IPv4(t, p, checker.TCP(
-		checker.TCPAckNum(uint32(wantAckNum)),
+		checker.TCPAckNum(wantAckNum),
 		func(t *testing.T, h header.Transport) {
 			tcp, ok := h.(header.TCP)
 			if !ok {
@@ -6484,14 +6479,14 @@ func TestReceiveBufferAutoTuning(t *testing.T) {
 	c.WindowScale = uint8(tcp.FindWndScale(maxReceiveBufferSize))
 
 	rawEP := c.CreateConnectedWithOptions(header.TCPSynOptions{TS: true, WS: 4})
-	tsVal := uint32(rawEP.TSVal)
+	tsVal := rawEP.TSVal
 	rawEP.NextSeqNum--
 	rawEP.SendPacketWithTS(nil, tsVal)
 	rawEP.NextSeqNum++
 	pkt := rawEP.VerifyAndReturnACKWithTS(tsVal)
 	curRcvWnd := int(header.TCP(header.IPv4(pkt).Payload()).WindowSize()) << c.WindowScale
 	scaleRcvWnd := func(rcvWnd int) uint16 {
-		return uint16(rcvWnd >> uint16(c.WindowScale))
+		return uint16(rcvWnd >> c.WindowScale)
 	}
 	// Allocate a large array to send to the endpoint.
 	b := make([]byte, receiveBufferSize*48)
@@ -6619,19 +6614,16 @@ func TestDelayEnabled(t *testing.T) {
 	defer c.Cleanup()
 	checkDelayOption(t, c, false, false) // Delay is disabled by default.
 
-	for _, v := range []struct {
-		delayEnabled    tcpip.TCPDelayEnabled
-		wantDelayOption bool
-	}{
-		{delayEnabled: false, wantDelayOption: false},
-		{delayEnabled: true, wantDelayOption: true},
-	} {
-		c := context.New(t, defaultMTU)
-		defer c.Cleanup()
-		if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &v.delayEnabled); err != nil {
-			t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, v.delayEnabled, v.delayEnabled, err)
-		}
-		checkDelayOption(t, c, v.delayEnabled, v.wantDelayOption)
+	for _, delayEnabled := range []bool{false, true} {
+		t.Run(fmt.Sprintf("delayEnabled=%t", delayEnabled), func(t *testing.T) {
+			c := context.New(t, defaultMTU)
+			defer c.Cleanup()
+			opt := tcpip.TCPDelayEnabled(delayEnabled)
+			if err := c.Stack().SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
+				t.Fatalf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, delayEnabled, err)
+			}
+			checkDelayOption(t, c, opt, delayEnabled)
+		})
 	}
 }
 
@@ -7042,7 +7034,7 @@ func TestTCPTimeWaitNewSyn(t *testing.T) {
 
 	// Receive the SYN-ACK reply.
 	b = c.GetPacket()
-	tcpHdr = header.TCP(header.IPv4(b).Payload())
+	tcpHdr = header.IPv4(b).Payload()
 	c.IRS = seqnum.Value(tcpHdr.SequenceNumber())
 
 	ackHeaders = &context.Headers{
@@ -7467,7 +7459,7 @@ func TestTCPUserTimeout(t *testing.T) {
 	checker.IPv4(t, c.GetPacket(),
 		checker.TCP(
 			checker.DstPort(context.TestPort),
-			checker.TCPSeqNum(uint32(next)),
+			checker.TCPSeqNum(next),
 			checker.TCPAckNum(uint32(0)),
 			checker.TCPFlags(header.TCPFlagRst),
 		),
@@ -7545,7 +7537,7 @@ func TestKeepaliveWithUserTimeout(t *testing.T) {
 		DstPort: c.Port,
 		Flags:   header.TCPFlagAck,
 		SeqNum:  iss,
-		AckNum:  seqnum.Value(c.IRS + 1),
+		AckNum:  c.IRS + 1,
 		RcvWnd:  30000,
 	})