types/netmap: remove redundant Netmap.Hostinfo

It was in SelfNode.Hostinfo anyway. The redundant copy was just
costing us an allocation per netmap (a Hostinfo.Clone).

Updates #1909

Change-Id: Ifac568aa5f8054d9419828489442a0f4559bc099
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

control/controlclient/map.go

@@ -467,9 +467,6 @@ func (ms *mapSession) netmap() *netmap.NetworkMap {
 		nm.Expiry = node.KeyExpiry()
 		nm.Name = node.Name()
 		nm.Addresses = filterSelfAddresses(node.Addresses().AsSlice())
-		if node.Hostinfo().Valid() {
-			nm.Hostinfo = *node.Hostinfo().AsStruct()
-		}
 		if node.MachineAuthorized() {
 			nm.MachineStatus = tailcfg.MachineAuthorized
 		} else {

ipn/ipnlocal/local.go

@@ -704,7 +704,9 @@ func (b *LocalBackend) updateStatus(sb *ipnstate.StatusBuilder, extraLocked func
 		ss.Online = health.GetInPollNetMap()
 		if b.netMap != nil {
 			ss.InNetworkMap = true
-			ss.HostName = b.netMap.Hostinfo.Hostname
+			if hi := b.netMap.SelfNode.Hostinfo(); hi.Valid() {
+				ss.HostName = hi.Hostname()
+			}
 			ss.DNSName = b.netMap.Name
 			ss.UserID = b.netMap.User()
 			if sn := b.netMap.SelfNode; sn.Valid() {

types/netmap/netmap.go

@@ -23,8 +23,6 @@ import (
 // The fields should all be considered read-only. They might
 // alias parts of previous NetworkMap values.
 type NetworkMap struct {
-	// Core networking
-
 	SelfNode   tailcfg.NodeView
 	NodeKey    key.NodePublic
 	PrivateKey key.NodePrivate
@@ -44,10 +42,10 @@ type NetworkMap struct {
 	MachineStatus tailcfg.MachineStatus
 
 	MachineKey key.MachinePublic
-	Peers      []tailcfg.NodeView // sorted by Node.ID
+
-	DNS        tailcfg.DNSConfig
+	Peers []tailcfg.NodeView // sorted by Node.ID
-	// TODO(maisem) : replace with View.
+	DNS   tailcfg.DNSConfig
-	Hostinfo          tailcfg.Hostinfo
+
 	PacketFilter      []filter.Match
 	PacketFilterRules views.Slice[tailcfg.FilterRule]
 	SSHPolicy         *tailcfg.SSHPolicy // or nil, if not enabled/allowed

wgengine/userspace.go

@@ -41,6 +41,7 @@ import (
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/netmap"
+	"tailscale.com/types/views"
 	"tailscale.com/util/clientmetric"
 	"tailscale.com/util/deephash"
 	"tailscale.com/util/mak"
@@ -755,12 +756,11 @@ 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 []netip.Prefix) bool {
+func hasOverlap(aips, rips views.Slice[netip.Prefix]) bool {
-	for _, aip := range aips {
+	for i := range aips.LenIter() {
-		for _, rip := range rips {
+		aip := aips.At(i)
-			if aip == rip {
+		if views.SliceContains(rips, aip) {
-				return true
+			return true
-			}
 		}
 	}
 	return false
@@ -800,9 +800,9 @@ func (e *userspaceEngine) Reconfig(cfg *wgcfg.Config, routerCfg *router.Config,
 
 	isSubnetRouter := false
 	if e.birdClient != nil && nm != nil && nm.SelfNode.Valid() {
-		isSubnetRouter = hasOverlap(nm.SelfNode.PrimaryRoutes().AsSlice(), nm.Hostinfo.RoutableIPs)
+		isSubnetRouter = hasOverlap(nm.SelfNode.PrimaryRoutes(), nm.SelfNode.Hostinfo().RoutableIPs())
 		e.logf("[v1] Reconfig: hasOverlap(%v, %v) = %v; isSubnetRouter=%v lastIsSubnetRouter=%v",
-			nm.SelfNode.PrimaryRoutes, nm.Hostinfo.RoutableIPs,
+			nm.SelfNode.PrimaryRoutes(), nm.SelfNode.Hostinfo().RoutableIPs(),
 			isSubnetRouter, isSubnetRouter, e.lastIsSubnetRouter)
 	}
 	isSubnetRouterChanged := isSubnetRouter != e.lastIsSubnetRouter