chore: bump minimum Go version to 1.24 (#85)

Signed-off-by: Marvin Drees <marvin.drees@9elements.com>

dhcpv4/client.go

@@ -153,10 +153,7 @@ func (c *Client) Encapsulate(carrierData []byte, offsetToIP, offsetToFrame int)
 		numOpts += n
 		n, _ = EncodeOption(opts[numOpts:], OptParameterRequestList, defaultParamReqList...)
 		numOpts += n
-		maxlen := len(dst)
-		if maxlen > math.MaxUint16 {
-			maxlen = math.MaxUint16
-		}
+		maxlen := min(len(dst), math.MaxUint16)
 		n, _ = EncodeOption16(opts[numOpts:], OptMaximumMessageSize, uint16(maxlen))
 		numOpts += n
 		if c.reqIP.valid {

dhcpv4/server_test.go

@@ -106,7 +106,7 @@ func TestServerMultipleClients(t *testing.T) {
 	}
 
 	// All assigned addresses must be unique.
-	for i := 0; i < nClients; i++ {
+	for i := range nClients {
 		for j := i + 1; j < nClients; j++ {
 			if assignedAddrs[i] == assignedAddrs[j] {
 				t.Errorf("clients %d and %d got same address %v", i, j, assignedAddrs[i])
@@ -123,7 +123,7 @@ func TestServerSequentialAddressAllocation(t *testing.T) {
 	sv.Configure(testServerConfig(svAddr))
 
 	// Build raw DISCOVER frames for two clients.
-	for i := byte(0); i < 2; i++ {
+	for i := range byte(2) {
 		var buf [512]byte
 		frm, _ := NewFrame(buf[:])
 		frm.ClearHeader()
@@ -147,7 +147,7 @@ func TestServerSequentialAddressAllocation(t *testing.T) {
 
 	// Encapsulate both OFFERs and verify addresses are in expected range.
 	var seen [2][4]byte
-	for i := byte(0); i < 2; i++ {
+	for i := range byte(2) {
 		var buf [512]byte
 		n, err := sv.Encapsulate(buf[:], -1, 0)
 		if err != nil {

dns/dns.go

@@ -489,7 +489,7 @@ func NewName(domain string) (Name, error) {
 // Returns an empty Name if n exceeds the number of labels.
 func (n Name) TrimLabels(skip int) Name {
 	off := 0
-	for i := 0; i < skip; i++ {
+	for range skip {
 		if off >= len(n.data) {
 			return Name{}
 		}

dns/dns_test.go

@@ -195,32 +195,32 @@ func TestMessageAppendEncodeIncompleteOK(t *testing.T) {
 
 func (m *Message) String() string {
 	// s := fmt.Sprintf("Message: %#v\n", &m.Header)
-	var s string
+	var s strings.Builder
 	if len(m.Questions) > 0 {
-		s += "-- Questions\n"
+		s.WriteString("-- Questions\n")
 		for _, q := range m.Questions {
-			s += fmt.Sprintf("%#v\n", q)
+			s.WriteString(fmt.Sprintf("%#v\n", q))
 		}
 	}
 	if len(m.Answers) > 0 {
-		s += "-- Answers\n"
+		s.WriteString("-- Answers\n")
 		for _, a := range m.Answers {
-			s += fmt.Sprintf("%#v\n", a)
+			s.WriteString(fmt.Sprintf("%#v\n", a))
 		}
 	}
 	if len(m.Authorities) > 0 {
-		s += "-- Authorities\n"
+		s.WriteString("-- Authorities\n")
 		for _, ns := range m.Authorities {
-			s += fmt.Sprintf("%#v\n", ns)
+			s.WriteString(fmt.Sprintf("%#v\n", ns))
 		}
 	}
 	if len(m.Additionals) > 0 {
-		s += "-- Additionals\n"
+		s.WriteString("-- Additionals\n")
 		for _, e := range m.Additionals {
-			s += fmt.Sprintf("%#v\n", e)
+			s.WriteString(fmt.Sprintf("%#v\n", e))
 		}
 	}
-	return s
+	return s.String()
 }
 
 func TestDecodeMessage(t *testing.T) {

go.mod

@@ -1,3 +1,3 @@
 module github.com/soypat/lneto
 
-go 1.23.8
+go 1.24

http/httpraw/cookie.go

@@ -76,7 +76,7 @@ func (c *Cookie) Parse() error {
 
 func (c *Cookie) ForEach(cb func(key, value []byte) error) error {
 	nc := len(c.kvs)
-	for i := 0; i < nc; i++ {
+	for i := range nc {
 		kv := c.kvs[i]
 		key := tok2bytes(c.buf, kv.key)
 		value := tok2bytes(c.buf, kv.value)
@@ -91,7 +91,7 @@ func (c *Cookie) ForEach(cb func(key, value []byte) error) error {
 // Get gets a cookie's value from its key. Use HasValueOrKey to check if a key or single-valued cookie is present in the cookie.
 func (c *Cookie) Get(key string) []byte {
 	nc := len(c.kvs)
-	for i := 0; i < nc; i++ {
+	for i := range nc {
 		kv := c.kvs[i]
 		if b2s(tok2bytes(c.buf, kv.key)) == key {
 			return tok2bytes(c.buf, kv.value)
@@ -102,7 +102,7 @@ func (c *Cookie) Get(key string) []byte {
 
 func (c *Cookie) HasKeyOrSingleValue(keyOrSingleValue string) bool {
 	nc := len(c.kvs)
-	for i := 0; i < nc; i++ {
+	for i := range nc {
 		kv := c.kvs[i]
 		if kv.key.len == 0 && b2s(tok2bytes(c.buf, kv.value)) == keyOrSingleValue ||
 			b2s(tok2bytes(c.buf, kv.key)) == keyOrSingleValue {
@@ -159,7 +159,7 @@ func (c *Cookie) String() string {
 // AppendKeyValues appends the HTTP header value of the cookie expected after the "Cookie:" string. Does not include trailing \r\n's.
 func (c *Cookie) AppendKeyValues(dst []byte) []byte {
 	nc := len(c.kvs)
-	for i := 0; i < nc; i++ {
+	for i := range nc {
 		kv := c.kvs[i]
 		key := tok2bytes(c.buf, kv.key)
 		value := tok2bytes(c.buf, kv.value)

http/httpraw/header.go

@@ -199,7 +199,7 @@ func (h *Header) ForEach(cb func(key, value []byte) error) error {
 
 func (hb *headerBuf) forEach(cb func(key, value []byte) error) error {
 	nh := len(hb.headers)
-	for i := 0; i < nh; i++ {
+	for i := range nh {
 		kv := hb.headers[i]
 		if !kv.isValid() {
 			continue

http/httpraw/parse_test.go

@@ -533,10 +533,7 @@ func TestParseRequest_InvalidHeaderSpaceBeforeColon(t *testing.T) {
 func splitInto(s string, n int) []string {
 	var chunks []string
 	for len(s) > 0 {
-		end := n
-		if end > len(s) {
-			end = len(s)
-		}
+		end := min(n, len(s))
 		chunks = append(chunks, s[:end])
 		s = s[end:]
 	}

internal/backoff.go

@@ -13,10 +13,8 @@ func BackoffConnRW(consecutiveBackoffs uint) {
 		maxShift       = 22
 		_overflowCheck = minWait << maxShift
 	)
-	wait := minWait << min(consecutiveBackoffs, maxShift)
-	if wait > maxWait {
-		wait = maxWait
-	}
+	shifted := minWait << min(consecutiveBackoffs, maxShift)
+	wait := min(shifted, maxWait)
 	time.Sleep(time.Duration(wait))
 }
 
@@ -31,9 +29,7 @@ func BackoffStackProto(consecutiveBackoffs uint) {
 		maxShift       = 22
 		_overflowCheck = minWait << maxShift
 	)
-	wait := minWait << min(consecutiveBackoffs, maxShift)
-	if wait > maxWait {
-		wait = maxWait
-	}
+	shifted := minWait << min(consecutiveBackoffs, maxShift)
+	wait := min(shifted, maxWait)
 	time.Sleep(time.Duration(wait))
 }

internal/ltesto/ltesto.go

@@ -490,10 +490,7 @@ func mutateTCPOptions(opts []byte, seed int64, variant int64) int64 {
 	case 4: // SACK with garbage block data.
 		if len(opts) >= 10 {
 			opts[0] = byte(tcp.OptSACK)   // kind=5
-			sackLen := len(opts)
-			if sackLen > 34 {
-				sackLen = 34 // max 4 SACK blocks
-			}
+			sackLen := min(len(opts), 34) // max 4 SACK blocks
 			opts[1] = byte(sackLen)
 			for i := 2; i < sackLen; i++ {
 				opts[i] = byte(seed)

internal/ring_test.go

@@ -20,7 +20,7 @@ func TestRing(t *testing.T) {
 	}
 	const data = "hello"
 	// Set random data and write some more and read it back.
-	for i := 0; i < 32; i++ {
+	for i := range 32 {
 		nfirst := max(1, rng.Intn(bufSize)/2)
 		nsecond := max(1, rng.Intn(bufSize)/2)
 		if nfirst+nsecond > bufSize {
@@ -59,7 +59,7 @@ func TestRing(t *testing.T) {
 	var zeros [bufSize]byte
 
 	// Set random data and write some more and read it back with ReadAt and ReadPeek and ReadDiscard.
-	for i := 0; i < 32; i++ {
+	for range 32 {
 		nfirst := rng.Intn(len(data))/2 + 1 // write garbage data first.
 		nsecond := rng.Intn(len(data))/2 + 1
 		if nfirst+nsecond > bufSize {
@@ -72,7 +72,7 @@ func TestRing(t *testing.T) {
 		content = append(content, data[:nsecond]...)
 		setRingData(t, r, randOff, content)
 		// Two-tap ReadPeek to make sure pointer not advanced.
-		for i := 0; i < 2; i++ {
+		for range 2 {
 			n, err = r.ReadPeek(readback[:])
 			if err != nil && err != io.EOF {
 				t.Fatal("read failed", err)
@@ -87,7 +87,7 @@ func TestRing(t *testing.T) {
 		}
 
 		// Two-tap ReadAt to make sure pointer not advanced.
-		for i := 0; i < 2; i++ {
+		for range 2 {
 			off := rng.Intn(nfirst + nsecond)
 			n, err = r.ReadAt(readback[:nfirst+nsecond-off], int64(off))
 
@@ -135,7 +135,7 @@ func TestRing2(t *testing.T) {
 	ringbuf := make([]byte, maxsize)
 	auxbuf := make([]byte, maxsize)
 	rng.Read(data)
-	for i := 0; i < ntests; i++ {
+	for i := range ntests {
 		dsize := max(rng.Intn(len(data)), 1)
 		if !testRing1_loopback(t, rng, ringbuf, data[:dsize], auxbuf) {
 			t.Fatalf("failed test %d", i)
@@ -156,7 +156,7 @@ func TestRingEmpty(t *testing.T) {
 		for _, isonReadEndCalled := range []bool{false, true} {
 			name := fmt.Sprintf("reset=%v readend=%v", isResetCalled, isonReadEndCalled)
 			t.Run(name, func(t *testing.T) {
-				for off := 0; off < bufSize+1; off++ {
+				for off := range bufSize + 1 {
 					r.End = 0
 					r.Off = off
 					if isResetCalled {
@@ -201,7 +201,7 @@ func TestRingNonEmpty(t *testing.T) {
 				name := fmt.Sprintf("readend=%v checkWrite=%v checkRead=%v", isonReadEndCalled, checkWrite, checkRead)
 				t.Run(name, func(t *testing.T) {
 					for end := 1; end < bufSize+1; end++ {
-						for off := 0; off < bufSize+1; off++ {
+						for off := range bufSize + 1 {
 							r.End = end
 							r.Off = off
 							buf := r.Buffered()
@@ -251,7 +251,7 @@ func TestRing_OffWrite(t *testing.T) {
 	var rawbuf, auxbuf, readback [bufSize]byte
 	r := &Ring{Buf: rawbuf[:]}
 	for n := 1; n < bufSize+1; n++ {
-		for off := 0; off < bufSize+1; off++ {
+		for off := range bufSize + 1 {
 			r.Off = off // Start write at off.
 			r.End = 0   // Reset to use no data.
 			for i := 0; i < n; i++ {
@@ -288,7 +288,7 @@ func TestRing_TwoWrite(t *testing.T) {
 	var rawbuf, auxbuf, readback [bufSize]byte
 	r := &Ring{Buf: rawbuf[:]}
 
-	for i := 0; i < 1024; i++ {
+	for range 1024 {
 		n1 := rng.Intn(bufSize-1) + 1 // leave space for one more write
 		n2 := rng.Intn(bufSize-n1) + 1
 		off := rng.Intn(bufSize + 1)
@@ -319,8 +319,8 @@ func TestRingOverwrite(t *testing.T) {
 	const bufSize = 8
 	var rawbuf, auxbuf [bufSize]byte
 	r := &Ring{Buf: rawbuf[:]}
-	for off := 0; off < bufSize+1; off++ {
-		for buf := 0; buf < bufSize+1; buf++ {
+	for off := range bufSize + 1 {
+		for buf := range bufSize + 1 {
 			setRingData(t, r, off, rawbuf[:buf])
 			// Select write size overwriting data.
 			for osz := bufSize - buf + 1; osz < bufSize+1; osz++ {
@@ -403,7 +403,7 @@ func TestRing_findcrash(t *testing.T) {
 	rng := rand.New(rand.NewSource(0))
 	data := make([]byte, maxsize)
 
-	for i := 0; i < ntests; i++ {
+	for i := range ntests {
 		free := r.Free()
 		if free < 0 {
 			t.Fatal("free < 0")
@@ -448,7 +448,7 @@ func TestRingFreeLimited(t *testing.T) {
 	rng := rand.New(rand.NewSource(1))
 	buffer := make([]byte, n)
 	r := Ring{Buf: buffer}
-	for itest := 0; itest < 100000; itest++ {
+	for itest := range 100000 {
 		r.Off = rng.Intn(n)
 		r.End = rng.Intn(n + 1)
 		limit := rng.Intn(n)

internal/slices.go

@@ -32,7 +32,7 @@ func DeleteZeroed[T comparable](a []T) []T {
 	var z T
 	off := 0
 	deleted := false
-	for i := 0; i < len(a); i++ {
+	for i := range a {
 		if a[i] != z {
 			if deleted {
 				a[off] = a[i]

internet/pcap/capture.go

@@ -771,7 +771,7 @@ func appendField(dst, pkt []byte, fieldBitStart, bitlen int, rightAligned bool)
 		if octets+octetsStart+1 > len(pkt) {
 			return dst, lneto.ErrShortBuffer
 		}
-		for i := 0; i < octets; i++ {
+		for i := range octets {
 			b := (pkt[octetsStart+i] & mask) << (8 - firstBitOffset)
 			b |= pkt[octetsStart+i+1] >> firstBitOffset
 			dst = append(dst, b)

internet/tcplistener_test.go

@@ -160,7 +160,7 @@ func TestListener_MultiConn(t *testing.T) {
 	var buf [2048]byte
 
 	// Complete full handshakes for all clients.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		expectExchange(t, &clientStacks[i], &serverStack, buf[:]) // SYN
 		expectExchange(t, &serverStack, &clientStacks[i], buf[:]) // SYN-ACK
 		expectExchange(t, &clientStacks[i], &serverStack, buf[:]) // ACK
@@ -173,7 +173,7 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Accept all connections.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		var err error
 		acceptedConns[i], _, err = listener.TryAccept()
 		if err != nil {
@@ -185,7 +185,7 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Verify all connections established.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		if clientConns[i].State() != tcp.StateEstablished {
 			t.Errorf("client %d: expected StateEstablished, got %s", i, clientConns[i].State())
 		}
@@ -195,7 +195,7 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Test data exchange: client -> server.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		msg := []byte("hello from client " + string('0'+byte(i)))
 		n, err := clientConns[i].Write(msg)
 		if err != nil {
@@ -207,12 +207,12 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Exchange data packets from all clients to server.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		expectExchange(t, &clientStacks[i], &serverStack, buf[:])
 	}
 
 	// Read data on server side and verify.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		expected := "hello from client " + string('0'+byte(i))
 		var readBuf [64]byte
 		n, err := acceptedConns[i].Read(readBuf[:])
@@ -225,7 +225,7 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Test data exchange: server -> client.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		msg := []byte("reply to client " + string('0'+byte(i)))
 		n, err := acceptedConns[i].Write(msg)
 		if err != nil {
@@ -237,12 +237,12 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Exchange data packets from server to all clients.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		expectExchange(t, &serverStack, &clientStacks[i], buf[:])
 	}
 
 	// Read responses on client side and verify.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		expected := "reply to client " + string('0'+byte(i))
 		var readBuf [64]byte
 		n, err := clientConns[i].Read(readBuf[:])
@@ -255,7 +255,7 @@ func TestListener_MultiConn(t *testing.T) {
 	}
 
 	// Close connections, alternating between client-initiated and server-initiated.
-	for i := 0; i < numClients; i++ {
+	for i := range numClients {
 		var closer, responder *StackIP
 		var closerConn, responderConn *tcp.Conn
 		var serverClosed bool

ipv4/frame_test.go

@@ -18,7 +18,7 @@ func TestFrame(t *testing.T) {
 	rng := rand.New(rand.NewSource(1))
 	const wantVersion = 4
 	v := new(lneto.Validator)
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		// SET VALUES:
 		wantIHL := uint8(5 + rng.Intn(10))
 		wantToS := ToS(rng.Intn(4))

ipv6/definitions.go

@@ -17,7 +17,7 @@ func AppendFormatAddr(dst []byte, addr [16]byte) []byte {
 	// Find the longest run of consecutive all-zero 16-bit groups for :: compression.
 	bestStart, bestLen := 0, 0
 	curStart := -1
-	for i := 0; i < 8; i++ {
+	for i := range 8 {
 		if addr[i*2] == 0 && addr[i*2+1] == 0 {
 			if curStart < 0 {
 				curStart = i

lneto_test.go

@@ -19,7 +19,7 @@ func TestTCPMarshalUnmarshal(t *testing.T) {
 	const maxSize = 4096
 	src := make([]byte, maxSize)
 	dst := make([]byte, maxSize)
-	for i := 0; i < 512; i++ {
+	for range 512 {
 		src = gen.AppendRandomIPv4TCPPacket(src[:0], rng, tcp.Segment{
 			SEQ:     tcp.Value(rng.Int()),
 			ACK:     tcp.Value(rng.Int()),

ntp/ntp.go

@@ -269,11 +269,11 @@ func (d Date) Time() (time.Time, error) {
 func CalculateSystemPrecision(nowNano func() int64, iters []int64) int8 {
 	maxIter := len(iters)
 	if nowNano == nil {
-		for i := 0; i < maxIter; i++ {
+		for i := range maxIter {
 			iters[i] = time.Now().UnixNano()
 		}
 	} else {
-		for i := 0; i < maxIter; i++ {
+		for i := range maxIter {
 			iters[i] = nowNano()
 		}
 	}

phy/phy.go

@@ -147,7 +147,7 @@ func (phy *Device) ResetPHY() (err error) {
 	const maxPolls = 50
 	const resetTimeout = 500 * time.Millisecond // As per standard.
 	var ctl BMCR
-	for i := 0; i < maxPolls; i++ {
+	for range maxPolls {
 		time.Sleep(resetTimeout / maxPolls)
 		ctl, err = phy.BasicControl()
 		if err != nil {

tcp/control_test.go

@@ -307,7 +307,7 @@ func TestPendingSegment_RetransmitAfter3DupACKs(t *testing.T) {
 	tcb.HelperInitRcv(remoteISS, remoteISS+1, wnd)
 
 	// Three duplicate ACKs against UNA must trigger retransmit state
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		dup := Segment{
 			SEQ:   remoteISS + 1,
 			ACK:   iss, // UNA (duplicate, no progress)
@@ -405,7 +405,7 @@ func TestACKLoop_MutualOutOfWindow(t *testing.T) {
 	tcbA.pending[0] = FlagACK
 
 	const maxRounds = 50
-	for round := 0; round < maxRounds; round++ {
+	for range maxRounds {
 		segA, okA := tcbA.PendingSegment(0)
 		if okA {
 			tcbA.Send(segA)

tcp/handler.go

@@ -431,13 +431,6 @@ func (h *Handler) IsTxOver() bool {
 		state == StateTimeWait && !h.scb.HasPending()
 }
 
-func min(a, b int) int {
-	if a < b {
-		return a
-	}
-	return b
-}
-
 func errstr(err error) string {
 	if err == nil {
 		return "<nil>"

tcp/handler_test.go

@@ -1002,7 +1002,7 @@ func TestHandler_RetransmitAfter3DupACKs(t *testing.T) {
 	if !client.scb.IncomingIsDupACK(dup.ACK) {
 		t.Fatal("MakeRetransmitDupACK return should be considered a duplicate ACK by remote")
 	}
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		fb, _ := NewFrame(pkt[:])
 		fb.SetSourcePort(server.LocalPort())
 		fb.SetDestinationPort(client.LocalPort())
@@ -1083,7 +1083,7 @@ func TestHandler_RetransmitAfterMultipleLossesBothDirections(t *testing.T) {
 		if !sender.scb.IncomingIsDupACK(dup.ACK) {
 			t.Fatal("dup ACK not recognized as dupack by sender")
 		}
-		for i := 0; i < 3; i++ {
+		for i := range 3 {
 			clear(pkt[:])
 			fb, _ := NewFrame(pkt[:])
 			fb.SetSourcePort(receiver.LocalPort())
@@ -1144,8 +1144,8 @@ func TestHandler_RetransmitAfterMultipleLossesBothDirections(t *testing.T) {
 	}
 
 	// Do several losses in client->server direction
-	for i := 0; i < loops; i++ {
-		payload := []byte(fmt.Sprintf("C->S loss %d", i))
+	for i := range loops {
+		payload := fmt.Appendf(nil, "C->S loss %d", i)
 		sendWithLoss(client, server, payload)
 		sendWithLoss(client, server, payload)
 		sendWithLoss(server, client, payload)

tcp/rst_test.go

@@ -86,7 +86,7 @@ func TestRSTQueue_DrainNegativeOffset(t *testing.T) {
 func TestRSTQueue_Full(t *testing.T) {
 	var q RSTQueue
 	addr := []byte{10, 0, 0, 1}
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		q.Queue(addr, uint16(i), 1234, Value(i), 0, FlagRST)
 	}
 	if q.Pending() != 4 {
@@ -143,7 +143,7 @@ func TestRSTQueue_MultipleDrains(t *testing.T) {
 	const offsetToTCP = 34
 
 	// Drain all 3 entries.
-	for i := 0; i < 3; i++ {
+	for i := range 3 {
 		setIPv4Version(carrier, offsetToIP)
 		n, err := q.Drain(carrier, offsetToIP, offsetToTCP)
 		if err != nil {

tcp/syncookie.go

@@ -161,7 +161,7 @@ func (sc *SYNCookieJar) hashTuple(srcAddr, dstAddr []byte, srcPort, dstPort uint
 	// Handle remaining bytes of srcAddr
 	if rem := len(srcAddr) % 4; rem != 0 {
 		var last uint32
-		for i := 0; i < rem; i++ {
+		for i := range rem {
 			last |= uint32(srcAddr[len(srcAddr)-rem+i]) << (i * 8)
 		}
 		h3 ^= last
@@ -174,7 +174,7 @@ func (sc *SYNCookieJar) hashTuple(srcAddr, dstAddr []byte, srcPort, dstPort uint
 	// Handle remaining bytes of dstAddr
 	if rem := len(dstAddr) % 4; rem != 0 {
 		var last uint32
-		for i := 0; i < rem; i++ {
+		for i := range rem {
 			last |= uint32(dstAddr[len(dstAddr)-rem+i]) << (i * 8)
 		}
 		h0 ^= last

tcp/txqueue_test.go

@@ -27,9 +27,9 @@ func TestRingTx_op(t *testing.T) {
 	dataSent := make([]byte, 0, maxBuf*10)
 	var rtx ringTx
 	rng := rand.New(rand.NewSource(0))
-	for iseed := int64(0); iseed < 1000; iseed++ {
+	for iseed := range int64(1000) {
 		rng.Seed(iseed + rng.Int63())
-		for itest := 0; itest < 32; itest++ {
+		for itest := range 32 {
 			bufsize := rng.Intn(maxBuf/2) + maxBuf/2
 			iss := Value(0)
 			npackets := rng.Intn(maxpkt-1) + 1
@@ -45,7 +45,7 @@ func TestRingTx_op(t *testing.T) {
 			nacked := 0
 			dataWritten = dataWritten[:0]
 			dataSent = dataSent[:0]
-			for iop := 0; iop < Nops; iop++ {
+			for iop := range Nops {
 				free := bufsize - nsent - nunsent
 				availPkt := rtx.slist.Free()
 				op := op(rng.Intn(int(opmax)))
@@ -180,7 +180,7 @@ func TestSentlist_simple(t *testing.T) {
 
 	// Test partial ack.
 	sl.AddPacket(pkt, 0, bufsize, sl.ssn)
-	for i := Value(0); i < pkt-1; i++ {
+	for range Value(pkt - 1) {
 		ack++
 		sl.RecvAck(ack, bufsize)
 		oldest = sl.Oldest()
@@ -208,7 +208,7 @@ func TestTxQueue_multipacket(t *testing.T) {
 	internalbuff := make([]byte, mtu)
 	rng := rand.New(rand.NewSource(3))
 	var wbuf, rbuf [mtu]byte
-	for itest := 0; itest < 32; itest++ {
+	for itest := range 32 {
 		rng.Seed(int64(itest))
 		err := rtx.Reset(internalbuff, maxPkts, iss)
 		if err != nil {
@@ -217,7 +217,7 @@ func TestTxQueue_multipacket(t *testing.T) {
 		numWrites := rng.Intn(maxWrites) + 1
 		total := 0
 		woff := 0
-		for iw := 0; iw < numWrites; iw++ {
+		for range numWrites {
 			wlen := rng.Intn(maxWriteSize) + 1
 			towrite := wbuf[woff : woff+wlen]
 			rng.Read(towrite)
@@ -234,7 +234,7 @@ func TestTxQueue_multipacket(t *testing.T) {
 		npkt := rng.Intn(maxPkts) + 1
 		roff := 0
 		seq := Value(iss)
-		for ipkt := 0; ipkt < npkt; ipkt++ {
+		for range npkt {
 			maxToPacket := min(total-roff, maxWriteSize)
 			pktlen := rng.Intn(maxToPacket) + 1
 			pkt := rbuf[roff : roff+pktlen]
@@ -289,7 +289,7 @@ func TestTxQueue(t *testing.T) {
 			name: "SequentialMessages",
 			test: func(t *testing.T) {
 				const startAck = 0
-				for i := 0; i < 10; i++ {
+				for range 10 {
 					rng.Read(msgBuf[:])
 					msgs := removeEmptyMsgs(bytes.SplitAfter(msgBuf[:], []byte{0}))
 					currentAck := Value(startAck)
@@ -314,7 +314,7 @@ func TestTxQueue(t *testing.T) {
 			name: "N-Messages",
 			test: func(t *testing.T) {
 				const startAck = 0
-				for i := 0; i < 10; i++ {
+				for range 10 {
 					rng.Read(msgBuf[:])
 					msgs := removeEmptyMsgs(bytes.SplitAfter(msgBuf[:], []byte{0}))
 					currentAck := Value(startAck)
@@ -362,7 +362,7 @@ func TestTxQueue(t *testing.T) {
 				const packets = 100
 				const maxPacketSize = bufsize / 4
 				var datalens [][]byte
-				for i := 0; i < 10; i++ {
+				for range 10 {
 					rng.Read(msgBuf[:])
 					err := rtx.Reset(ringBuf[:], packets, startAck)
 					if err != nil {

udp/conn_test.go

@@ -163,7 +163,7 @@ func TestConn_ReadTruncates(t *testing.T) {
 
 func TestConn_DemuxExhausted(t *testing.T) {
 	conn := newTestConn(t) // queue size 4
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		frame := makeUDPFrame(8080, 1234, []byte{byte(i)})
 		err := conn.Demux(frame, 0)
 		if err != nil {

x/xnet/stack-berkeley.go

@@ -31,7 +31,7 @@ const (
 // family must be syscall.AF_INET. SOCK_STREAM is only one supported for now since is TCP.
 // network supported for now is "tcp" or "tcp4". A nil remote address and defined local address means net.Listener is returned.
 // if remote address defined then is active connection, returns a net.Conn.
-type gosocket = func(ctx context.Context, network string, family, sotype int, laddr, raddr net.Addr) (c interface{}, err error)
+type gosocket = func(ctx context.Context, network string, family, sotype int, laddr, raddr net.Addr) (c any, err error)
 
 type socket[T any] struct {
 	sockfd int
@@ -84,7 +84,7 @@ func (s *StackBerkeley) Bind(sockfd int, ip netip.AddrPort) error {
 }
 
 // SetSockOpt sets a socket option on sockfd. Currently unimplemented.
-func (s *StackBerkeley) SetSockOpt(sockfd int, level int, opt int, value interface{}) error {
+func (s *StackBerkeley) SetSockOpt(sockfd int, level int, opt int, value any) error {
 	return nil
 }
 

x/xnet/stack-blocking.go

@@ -41,7 +41,7 @@ func (s StackBlocking) DoDHCPv4(reqAddr [4]byte, timeout time.Duration) (*DHCPRe
 	deadline := time.Now().Add(timeout)
 	requested := false
 	var lastState dhcpv4.ClientState
-	for i := 0; i < maxIter; i++ {
+	for range maxIter {
 		s.async.mu.Lock()
 		state := s.async.dhcp.State()
 		s.async.mu.Unlock()
@@ -80,7 +80,7 @@ func (s StackBlocking) DoPing(hostAddr netip.Addr, timeout time.Duration) (round
 	}
 	start := time.Now()
 	var backoffs uint
-	for i := 0; i < maxIter; i++ {
+	for range maxIter {
 		s.async.mu.Lock()
 		completed, exists := s.async.icmp.PingPop(key)
 		s.async.mu.Unlock()
@@ -108,7 +108,7 @@ func (s StackBlocking) DoNTP(hostAddr netip.Addr, timeout time.Duration) (offset
 	deadline := time.Now().Add(timeout)
 	var done bool
 	var backoffs uint
-	for i := 0; i < maxIter; i++ {
+	for range maxIter {
 		offset, done = s.async.ResultNTPOffset()
 		if done {
 			return offset, nil
@@ -128,7 +128,7 @@ func (s StackBlocking) DoResolveHardwareAddress6(addr netip.Addr, timeout time.D
 	}
 	var backoffs uint
 	deadline := time.Now().Add(timeout)
-	for i := 0; i < maxIter; i++ {
+	for range maxIter {
 		hw, err = s.async.ResultResolveHardwareAddress6(addr)
 		if err == nil {
 			break
@@ -152,7 +152,7 @@ func (s StackBlocking) DoLookupIP(host string, timeout time.Duration) (addrs []n
 
 	deadline := time.Now().Add(timeout)
 	var backoffs uint
-	for i := 0; i < maxIter; i++ {
+	for range maxIter {
 		addrs, completed, err := s.async.ResultLookupIP(host)
 		if completed {
 			return addrs, err
@@ -174,7 +174,7 @@ func (s StackBlocking) DoDialTCP(conn *tcp.Conn, localPort uint16, addrp netip.A
 	}
 	deadline := time.Now().Add(timeout)
 	var backoffs uint
-	for i := 0; i < maxIter; i++ {
+	for range maxIter {
 		state := conn.State()
 		if state == tcp.StateEstablished {
 			return nil

x/xnet/stack-go.go

@@ -38,7 +38,7 @@ type StackGo struct {
 	plcfg TCPPoolConfig
 }
 
-func (s StackGo) Socket(ctx context.Context, network string, family, sotype int, laddr, raddr net.Addr) (c interface{}, err error) {
+func (s StackGo) Socket(ctx context.Context, network string, family, sotype int, laddr, raddr net.Addr) (c any, err error) {
 	switch family {
 	case syscall.AF_INET:
 	default:
@@ -60,7 +60,7 @@ func (s StackGo) Socket(ctx context.Context, network string, family, sotype int,
 	return s.SocketNetip(ctx, network, family, sotype, local, remote)
 }
 
-func (s StackGo) SocketNetip(ctx context.Context, network string, family, sotype int, laddr, raddr netip.AddrPort) (c interface{}, err error) {
+func (s StackGo) SocketNetip(ctx context.Context, network string, family, sotype int, laddr, raddr netip.AddrPort) (c any, err error) {
 	switch family {
 	case syscall.AF_INET:
 	default:

x/xnet/stack-retrying.go

@@ -25,7 +25,7 @@ type StackRetrying struct {
 
 func (s StackRetrying) DoDHCPv4(reqAddr [4]byte, timeout time.Duration, retries int) (results *DHCPResults, err error) {
 	expectEnd := time.Now().Add(timeout * time.Duration(retries))
-	for i := 0; i < retries; i++ {
+	for i := range retries {
 		if i > 0 {
 			println("Retrying DHCP")
 		}
@@ -42,7 +42,7 @@ func (s StackRetrying) DoDHCPv4(reqAddr [4]byte, timeout time.Duration, retries
 
 func (s StackRetrying) DoNTP(ntpHost netip.Addr, timeout time.Duration, retries int) (offset time.Duration, err error) {
 	expectEnd := time.Now().Add(timeout * time.Duration(retries))
-	for i := 0; i < retries; i++ {
+	for i := range retries {
 		if i > 0 {
 			println("Retrying NTP")
 		}
@@ -61,7 +61,7 @@ func (s StackRetrying) DoLookupIP(host string, timeout time.Duration, retries in
 		return nil, errNoDNSServer
 	}
 	expectEnd := time.Now().Add(timeout * time.Duration(retries))
-	for i := 0; i < retries; i++ {
+	for range retries {
 		addrs, err = s.block.DoLookupIP(host, timeout)
 		if err == nil {
 			return addrs, nil
@@ -75,7 +75,7 @@ func (s StackRetrying) DoLookupIP(host string, timeout time.Duration, retries in
 
 func (s StackRetrying) DoResolveHardwareAddress6(addr netip.Addr, timeout time.Duration, retries int) (hw [6]byte, err error) {
 	expectEnd := time.Now().Add(timeout * time.Duration(retries))
-	for i := 0; i < retries; i++ {
+	for range retries {
 		hw, err = s.block.DoResolveHardwareAddress6(addr, timeout)
 		if err == nil {
 			return hw, nil
@@ -90,7 +90,7 @@ func (s StackRetrying) DoResolveHardwareAddress6(addr netip.Addr, timeout time.D
 func (s StackRetrying) DoDialTCP(conn *tcp.Conn, localPort uint16, addrp netip.AddrPort, timeout time.Duration, retries int) (err error) {
 	expectEnd := time.Now().Add(timeout * time.Duration(retries))
 	var firstErr error
-	for i := 0; i < retries; i++ {
+	for range retries {
 		err = s.block.DoDialTCP(conn, localPort, addrp, timeout)
 		if err == nil {
 			return nil

x/xnet/xnet_concurrent_test.go

@@ -259,7 +259,7 @@ func runClient(t *testing.T, id int, stack *StackAsync, conn *tcp.Conn,
 	}
 
 	// Send test data.
-	testData := []byte(fmt.Sprintf("hello from client %d", id))
+	testData := fmt.Appendf(nil, "hello from client %d", id)
 	_, err = conn.Write(testData)
 	if err != nil {
 		t.Errorf("client %d write failed: %v", id, err)

x/xnet/xnet_dns_test.go

@@ -3,6 +3,7 @@ package xnet
 import (
 	"errors"
 	"net/netip"
+	"slices"
 	"testing"
 
 	"github.com/soypat/lneto"
@@ -87,13 +88,7 @@ func TestDNS_QueryReceivesAnswer(t *testing.T) {
 		t.Fatal("no addresses returned from DNS lookup")
 	}
 
-	found := false
-	for _, addr := range addrs {
-		if addr == wantAddr {
-			found = true
-			break
-		}
-	}
+	found := slices.Contains(addrs, wantAddr)
 	if !found {
 		t.Errorf("expected address %s not found in result %v", wantAddr, addrs)
 	}

x/xnet/xnet_fuzz_test.go

@@ -532,7 +532,7 @@ func testStackSeeded(t *testing.T, seed1, seed2 int64) {
 		// Hard ceiling prevents infinite send loops from passing silently.
 		// Also send drained packet to other stack to also catch infinite feedback loops.
 		const drainLimit = 8
-		for d := 0; d < drainLimit; d++ {
+		for d := range drainLimit {
 			limit := d == drainLimit-1
 			n, err := first.EgressEthernet(buf[:])
 			if (err != nil || n > 0) && limit {

x/xnet/xnet_test.go

@@ -127,7 +127,7 @@ func TestStackAsyncTCP_multipacket(t *testing.T) {
 		tst.TestTCPSetupAndEstablish(sv, client, svconn, clconn, svPort, 1337)
 		testClose()
 		var buf [MTU]byte
-		for i := 0; i < 20; i++ {
+		for range 20 {
 			payloadSize := rng.Intn(maxPktLen) + 1
 			tst.TestTCPSetupAndEstablish(sv, client, svconn, clconn, svPort, 1337)
 			// npkt := rng.Intn(maxNPkt-1) + 2