all: use Go 1.22 range-over-int

Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

control/controlbase/conn_test.go

@@ -91,7 +91,7 @@ func TestFastPath(t *testing.T) {
 
 	const packets = 10
 	s := "test"
-	for i := 0; i < packets; i++ {
+	for range packets {
 		// Many separate writes, to force separate Noise frames that
 		// all get buffered up and then all sent as a single slice to
 		// the server.
@@ -251,7 +251,7 @@ func TestConnMemoryOverhead(t *testing.T) {
 	}
 	defer closeAll()
 
-	for i := 0; i < num; i++ {
+	for range num {
 		client, server := pair(t)
 		closers = append(closers, client, server)
 		go func() {

control/controlbase/handshake_test.go

@@ -64,7 +64,7 @@ func TestNoReuse(t *testing.T) {
 		serverHandshakes = map[[48]byte]bool{}
 		packets          = map[[32]byte]bool{}
 	)
-	for i := 0; i < 10; i++ {
+	for range 10 {
 		var (
 			clientRaw, serverRaw = memnet.NewConn("noise", 128000)
 			clientBuf, serverBuf bytes.Buffer
@@ -162,7 +162,7 @@ func (r *tamperReader) Read(bs []byte) (int, error) {
 
 func TestTampering(t *testing.T) {
 	// Tamper with every byte of the client initiation message.
-	for i := 0; i < 101; i++ {
+	for i := range 101 {
 		var (
 			clientConn, serverRaw = memnet.NewConn("noise", 128000)
 			serverConn            = &readerConn{serverRaw, &tamperReader{serverRaw, i, 0}}
@@ -190,7 +190,7 @@ func TestTampering(t *testing.T) {
 	}
 
 	// Tamper with every byte of the server response message.
-	for i := 0; i < 51; i++ {
+	for i := range 51 {
 		var (
 			clientRaw, serverConn = memnet.NewConn("noise", 128000)
 			clientConn            = &readerConn{clientRaw, &tamperReader{clientRaw, i, 0}}
@@ -215,7 +215,7 @@ func TestTampering(t *testing.T) {
 	}
 
 	// Tamper with every byte of the first server>client transport message.
-	for i := 0; i < 30; i++ {
+	for i := range 30 {
 		var (
 			clientRaw, serverConn = memnet.NewConn("noise", 128000)
 			clientConn            = &readerConn{clientRaw, &tamperReader{clientRaw, 51 + i, 0}}
@@ -256,7 +256,7 @@ func TestTampering(t *testing.T) {
 	}
 
 	// Tamper with every byte of the first client>server transport message.
-	for i := 0; i < 30; i++ {
+	for i := range 30 {
 		var (
 			clientConn, serverRaw = memnet.NewConn("noise", 128000)
 			serverConn            = &readerConn{serverRaw, &tamperReader{serverRaw, 101 + i, 0}}

control/controlclient/controlclient_test.go

@@ -9,7 +9,7 @@ import (
 )
 
 func fieldsOf(t reflect.Type) (fields []string) {
-	for i := 0; i < t.NumField(); i++ {
+	for i := range t.NumField() {
 		if name := t.Field(i).Name; name != "_" {
 			fields = append(fields, name)
 		}

control/controlclient/map.go

@@ -563,7 +563,7 @@ var nodeFields = sync.OnceValue(getNodeFields)
 func getNodeFields() []string {
 	rt := reflect.TypeFor[tailcfg.Node]()
 	ret := make([]string, rt.NumField())
-	for i := 0; i < rt.NumField(); i++ {
+	for i := range rt.NumField() {
 		ret[i] = rt.Field(i).Name
 	}
 	return ret

control/controlclient/map_test.go

@@ -1019,7 +1019,7 @@ func BenchmarkMapSessionDelta(b *testing.B) {
 					Name: "foo.bar.ts.net.",
 				},
 			}
-			for i := 0; i < size; i++ {
+			for i := range size {
 				res.Peers = append(res.Peers, &tailcfg.Node{
 					ID:         tailcfg.NodeID(i + 2),
 					Name:       fmt.Sprintf("peer%d.bar.ts.net.", i),
@@ -1046,7 +1046,7 @@ func BenchmarkMapSessionDelta(b *testing.B) {
 
 			// Now for the core of the benchmark loop, just toggle
 			// a single node's online status.
-			for i := 0; i < b.N; i++ {
+			for i := range b.N {
 				if err := ms.HandleNonKeepAliveMapResponse(ctx, &tailcfg.MapResponse{
 					OnlineChange: map[tailcfg.NodeID]bool{
 						2: i%2 == 0,

control/controlhttp/http_test.go

@@ -729,7 +729,7 @@ func (d *closeTrackDialer) Done() {
 	// Sleep/wait a few times on the assumption that things will close
 	// "eventually".
 	const iters = 100
-	for i := 0; i < iters; i++ {
+	for i := range iters {
 		d.mu.Lock()
 		if len(d.conns) == 0 {
 			d.mu.Unlock()