all: use iterators over slice views more

This gets close to all of the remaining ones.

Updates #12912

Change-Id: I9c672bbed2654a6c5cab31e0cbece6c107d8c6fa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/ipnlocal/drive.go

@@ -354,9 +354,8 @@ func (b *LocalBackend) driveRemotesFromPeers(nm *netmap.NetworkMap) []*drive.Rem
 
 				// Check that the peer is allowed to share with us.
 				addresses := peer.Addresses()
-				for i := range addresses.Len() {
-					addr := addresses.At(i)
-					capsMap := b.PeerCaps(addr.Addr())
+				for _, p := range addresses.All() {
+					capsMap := b.PeerCaps(p.Addr())
 					if capsMap.HasCapability(tailcfg.PeerCapabilityTaildriveSharer) {
 						return true
 					}

ipn/ipnlocal/local.go

@@ -1811,8 +1811,7 @@ func setExitNodeID(prefs *ipn.Prefs, nm *netmap.NetworkMap, lastSuggestedExitNod
 	}
 
 	for _, peer := range nm.Peers {
-		for i := range peer.Addresses().Len() {
-			addr := peer.Addresses().At(i)
+		for _, addr := range peer.Addresses().All() {
 			if !addr.IsSingleIP() || addr.Addr() != prefs.ExitNodeIP {
 				continue
 			}
@@ -4997,8 +4996,8 @@ func (b *LocalBackend) enterStateLockedOnEntry(newState ipn.State, unlock unlock
 	case ipn.Running:
 		var addrStrs []string
 		addrs := netMap.GetAddresses()
-		for i := range addrs.Len() {
-			addrStrs = append(addrStrs, addrs.At(i).Addr().String())
+		for _, p := range addrs.All() {
+			addrStrs = append(addrStrs, p.Addr().String())
 		}
 		systemd.Status("Connected; %s; %s", activeLogin, strings.Join(addrStrs, " "))
 	case ipn.NoState:
@@ -6089,8 +6088,7 @@ func (b *LocalBackend) SetDNS(ctx context.Context, name, value string) error {
 
 func peerAPIPorts(peer tailcfg.NodeView) (p4, p6 uint16) {
 	svcs := peer.Hostinfo().Services()
-	for i := range svcs.Len() {
-		s := svcs.At(i)
+	for _, s := range svcs.All() {
 		switch s.Proto {
 		case tailcfg.PeerAPI4:
 			p4 = s.Port
@@ -6122,8 +6120,7 @@ func peerAPIBase(nm *netmap.NetworkMap, peer tailcfg.NodeView) string {
 
 	var have4, have6 bool
 	addrs := nm.GetAddresses()
-	for i := range addrs.Len() {
-		a := addrs.At(i)
+	for _, a := range addrs.All() {
 		if !a.IsSingleIP() {
 			continue
 		}
@@ -6145,10 +6142,9 @@ func peerAPIBase(nm *netmap.NetworkMap, peer tailcfg.NodeView) string {
 }
 
 func nodeIP(n tailcfg.NodeView, pred func(netip.Addr) bool) netip.Addr {
-	for i := range n.Addresses().Len() {
-		a := n.Addresses().At(i)
-		if a.IsSingleIP() && pred(a.Addr()) {
-			return a.Addr()
+	for _, pfx := range n.Addresses().All() {
+		if pfx.IsSingleIP() && pred(pfx.Addr()) {
+			return pfx.Addr()
 		}
 	}
 	return netip.Addr{}
@@ -6378,8 +6374,8 @@ func peerCanProxyDNS(p tailcfg.NodeView) bool {
 	// If p.Cap is not populated (e.g. older control server), then do the old
 	// thing of searching through services.
 	services := p.Hostinfo().Services()
-	for i := range services.Len() {
-		if s := services.At(i); s.Proto == tailcfg.PeerAPIDNS && s.Port >= 1 {
+	for _, s := range services.All() {
+		if s.Proto == tailcfg.PeerAPIDNS && s.Port >= 1 {
 			return true
 		}
 	}

ipn/ipnlocal/local_test.go

@@ -3041,12 +3041,10 @@ func deterministicNodeForTest(t testing.TB, want views.Slice[tailcfg.StableNodeI
 		var ret tailcfg.NodeView
 
 		gotIDs := make([]tailcfg.StableNodeID, got.Len())
-		for i := range got.Len() {
-			nv := got.At(i)
+		for i, nv := range got.All() {
 			if !nv.Valid() {
 				t.Fatalf("invalid node at index %v", i)
 			}
-
 			gotIDs[i] = nv.StableID()
 			if nv.StableID() == use {
 				ret = nv

ipn/ipnlocal/network-lock.go

@@ -430,8 +430,7 @@ func (b *LocalBackend) tkaBootstrapFromGenesisLocked(g tkatype.MarshaledAUM, per
 		}
 		bootstrapStateID := fmt.Sprintf("%d:%d", genesis.State.StateID1, genesis.State.StateID2)
 
-		for i := range persist.DisallowedTKAStateIDs().Len() {
-			stateID := persist.DisallowedTKAStateIDs().At(i)
+		for _, stateID := range persist.DisallowedTKAStateIDs().All() {
 			if stateID == bootstrapStateID {
 				return fmt.Errorf("TKA with stateID of %q is disallowed on this node", stateID)
 			}
@@ -572,8 +571,7 @@ func tkaStateFromPeer(p tailcfg.NodeView) ipnstate.TKAPeer {
 		TailscaleIPs: make([]netip.Addr, 0, p.Addresses().Len()),
 		NodeKey:      p.Key(),
 	}
-	for i := range p.Addresses().Len() {
-		addr := p.Addresses().At(i)
+	for _, addr := range p.Addresses().All() {
 		if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
 			fp.TailscaleIPs = append(fp.TailscaleIPs, addr.Addr())
 		}

ipn/ipnlocal/serve.go

@@ -242,8 +242,7 @@ func (b *LocalBackend) updateServeTCPPortNetMapAddrListenersLocked(ports []uint1
 	}
 
 	addrs := nm.GetAddresses()
-	for i := range addrs.Len() {
-		a := addrs.At(i)
+	for _, a := range addrs.All() {
 		for _, p := range ports {
 			addrPort := netip.AddrPortFrom(a.Addr(), p)
 			if _, ok := b.serveListeners[addrPort]; ok {

ipn/ipnlocal/web_client.go

@@ -121,8 +121,8 @@ func (b *LocalBackend) updateWebClientListenersLocked() {
 	}
 
 	addrs := b.netMap.GetAddresses()
-	for i := range addrs.Len() {
-		addrPort := netip.AddrPortFrom(addrs.At(i).Addr(), webClientPort)
+	for _, pfx := range addrs.All() {
+		addrPort := netip.AddrPortFrom(pfx.Addr(), webClientPort)
 		if _, ok := b.webClientListeners[addrPort]; ok {
 			continue // already listening
 		}