all: remove LenIter, use Go 1.22 range-over-int instead

Updates #11058
Updates golang/go#65685

Change-Id: Ibb216b346e511d486271ab3d84e4546c521e4e22
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

wgengine/magicsock/debughttp.go

@@ -102,7 +102,7 @@ func (c *Conn) ServeHTTPDebug(w http.ResponseWriter, r *http.Request) {
 		sort.Slice(ent, func(i, j int) bool { return ent[i].pub.Less(ent[j].pub) })
 
 		peers := map[key.NodePublic]tailcfg.NodeView{}
-		for i := range c.peers.LenIter() {
+		for i := range c.peers.Len() {
 			p := c.peers.At(i)
 			peers[p.Key()] = p
 		}

wgengine/magicsock/endpoint.go

@@ -1366,7 +1366,7 @@ func (de *endpoint) updateFromNode(n tailcfg.NodeView, heartbeatDisabled bool, p
 }
 
 func (de *endpoint) setEndpointsLocked(eps interface {
-	LenIter() []struct{}
+	Len() int
 	At(i int) netip.AddrPort
 }) {
 	for _, st := range de.endpointState {
@@ -1374,7 +1374,7 @@ func (de *endpoint) setEndpointsLocked(eps interface {
 	}
 
 	var newIpps []netip.AddrPort
-	for i := range eps.LenIter() {
+	for i := range eps.Len() {
 		if i > math.MaxInt16 {
 			// Seems unlikely.
 			break

wgengine/magicsock/magicsock.go

@@ -1793,7 +1793,7 @@ func nodesEqual(x, y views.Slice[tailcfg.NodeView]) bool {
 	if x.Len() != y.Len() {
 		return false
 	}
-	for i := range x.LenIter() {
+	for i := range x.Len() {
 		if !x.At(i).Equal(y.At(i)) {
 			return false
 		}
@@ -2056,7 +2056,7 @@ func (c *Conn) logEndpointCreated(n tailcfg.NodeView) {
 			fmt.Fprintf(w, "derp=%v%s ", regionID, code)
 		}
 
-		for i := range n.AllowedIPs().LenIter() {
+		for i := range n.AllowedIPs().Len() {
 			a := n.AllowedIPs().At(i)
 			if a.IsSingleIP() {
 				fmt.Fprintf(w, "aip=%v ", a.Addr())
@@ -2064,7 +2064,7 @@ func (c *Conn) logEndpointCreated(n tailcfg.NodeView) {
 				fmt.Fprintf(w, "aip=%v ", a)
 			}
 		}
-		for i := range n.Endpoints().LenIter() {
+		for i := range n.Endpoints().Len() {
 			ep := n.Endpoints().At(i)
 			fmt.Fprintf(w, "ep=%v ", ep)
 		}

wgengine/netstack/netstack.go

@@ -366,12 +366,12 @@ func (ns *Impl) UpdateNetstackIPs(nm *netmap.NetworkMap) {
 	newPfx := make(map[netip.Prefix]bool)
 
 	if selfNode.Valid() {
-		for i := range selfNode.Addresses().LenIter() {
+		for i := range selfNode.Addresses().Len() {
 			p := selfNode.Addresses().At(i)
 			newPfx[p] = true
 		}
 		if ns.ProcessSubnets {
-			for i := range selfNode.AllowedIPs().LenIter() {
+			for i := range selfNode.AllowedIPs().Len() {
 				p := selfNode.AllowedIPs().At(i)
 				newPfx[p] = true
 			}

wgengine/pendopen.go

@@ -160,7 +160,7 @@ func (e *userspaceEngine) onOpenTimeout(flow flowtrack.Tuple) {
 	ps, found := e.getPeerStatusLite(n.Key())
 	if !found {
 		onlyZeroRoute := true // whether peerForIP returned n only because its /0 route matched
-		for i := range n.AllowedIPs().LenIter() {
+		for i := range n.AllowedIPs().Len() {
 			r := n.AllowedIPs().At(i)
 			if r.Bits() != 0 && r.Contains(flow.Dst.Addr()) {
 				onlyZeroRoute = false

wgengine/userspace.go

@@ -780,7 +780,7 @@ func (e *userspaceEngine) updateActivityMapsLocked(trackNodes []key.NodePublic,
 // hasOverlap checks if there is a IPPrefix which is common amongst the two
 // provided slices.
 func hasOverlap(aips, rips views.Slice[netip.Prefix]) bool {
-	for i := range aips.LenIter() {
+	for i := range aips.Len() {
 		aip := aips.At(i)
 		if views.SliceContains(rips, aip) {
 			return true
@@ -1233,7 +1233,7 @@ func (e *userspaceEngine) mySelfIPMatchingFamily(dst netip.Addr) (src netip.Addr
 	if addrs.Len() == 0 {
 		return zero, errors.New("no self address in netmap")
 	}
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		if a := addrs.At(i); a.IsSingleIP() && a.Addr().BitLen() == dst.BitLen() {
 			return a.Addr(), nil
 		}
@@ -1379,7 +1379,7 @@ func (e *userspaceEngine) PeerForIP(ip netip.Addr) (ret PeerForIP, ok bool) {
 	// Check for exact matches before looking for subnet matches.
 	// TODO(bradfitz): add maps for these. on NetworkMap?
 	for _, p := range nm.Peers {
-		for i := range p.Addresses().LenIter() {
+		for i := range p.Addresses().Len() {
 			a := p.Addresses().At(i)
 			if a.Addr() == ip && a.IsSingleIP() && tsaddr.IsTailscaleIP(ip) {
 				return PeerForIP{Node: p, Route: a}, true
@@ -1387,7 +1387,7 @@ func (e *userspaceEngine) PeerForIP(ip netip.Addr) (ret PeerForIP, ok bool) {
 		}
 	}
 	addrs := nm.GetAddresses()
-	for i := range addrs.LenIter() {
+	for i := range addrs.Len() {
 		if a := addrs.At(i); a.Addr() == ip && a.IsSingleIP() && tsaddr.IsTailscaleIP(ip) {
 			return PeerForIP{Node: nm.SelfNode, IsSelf: true, Route: a}, true
 		}

wgengine/wgcfg/nmcfg/nmcfg.go

@@ -41,7 +41,7 @@ func cidrIsSubnet(node tailcfg.NodeView, cidr netip.Prefix) bool {
 	if !cidr.IsSingleIP() {
 		return true
 	}
-	for i := range node.Addresses().LenIter() {
+	for i := range node.Addresses().Len() {
 		selfCIDR := node.Addresses().At(i)
 		if cidr == selfCIDR {
 			return false
@@ -100,7 +100,7 @@ func WGCfg(nm *netmap.NetworkMap, logf logger.Logf, flags netmap.WGConfigFlags,
 		didExitNodeWarn := false
 		cpeer.V4MasqAddr = peer.SelfNodeV4MasqAddrForThisPeer()
 		cpeer.V6MasqAddr = peer.SelfNodeV6MasqAddrForThisPeer()
-		for i := range peer.AllowedIPs().LenIter() {
+		for i := range peer.AllowedIPs().Len() {
 			allowedIP := peer.AllowedIPs().At(i)
 			if allowedIP.Bits() == 0 && peer.StableID() != exitNode {
 				if didExitNodeWarn {