From 91d23babef688c3564d445cdacd91c7c55bd66da Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@tailscale.com>
Date: Sat, 15 Nov 2025 10:28:09 -0800
Subject: [PATCH] types/netmap: remove some useless denormalized fields from
 NetworkMap

Updates #12639

Change-Id: Iec51c280141e22a0e3501df2053f2435e16fc0c8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
---
 control/controlclient/auto.go   |  2 +-
 control/controlclient/direct.go |  2 +-
 control/controlclient/map.go    |  2 --
 ipn/ipnlocal/local.go           |  4 ++--
 ipn/ipnlocal/node_backend.go    |  2 +-
 net/tsdial/dnsmap.go            |  8 ++++----
 types/netmap/netmap.go          | 23 +++++++++++++++++------
 7 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/control/controlclient/auto.go b/control/controlclient/auto.go
index 9d648409b..58d4864b2 100644
--- a/control/controlclient/auto.go
+++ b/control/controlclient/auto.go
@@ -424,7 +424,7 @@ func (mrs mapRoutineState) UpdateFullNetmap(nm *netmap.NetworkMap) {
 
 	c.mu.Lock()
 	c.inMapPoll = true
-	c.expiry = nm.Expiry
+	c.expiry = nm.SelfKeyExpiry()
 	stillAuthed := c.loggedIn
 	c.logf("[v1] mapRoutine: netmap received: loggedIn=%v inMapPoll=true", stillAuthed)
 	c.mu.Unlock()
diff --git a/control/controlclient/direct.go b/control/controlclient/direct.go
index d30db6191..d64ed7bf3 100644
--- a/control/controlclient/direct.go
+++ b/control/controlclient/direct.go
@@ -1085,7 +1085,7 @@ func (c *Direct) sendMapRequest(ctx context.Context, isStreaming bool, nu Netmap
 			c.persist = newPersist.View()
 			persist = c.persist
 		}
-		c.expiry = nm.Expiry
+		c.expiry = nm.SelfKeyExpiry()
 	}
 
 	// gotNonKeepAliveMessage is whether we've yet received a MapResponse message without
diff --git a/control/controlclient/map.go b/control/controlclient/map.go
index eafdb2d56..df85aed52 100644
--- a/control/controlclient/map.go
+++ b/control/controlclient/map.go
@@ -892,8 +892,6 @@ func (ms *mapSession) netmap() *netmap.NetworkMap {
 
 	if node := ms.lastNode; node.Valid() {
 		nm.SelfNode = node
-		nm.Expiry = node.KeyExpiry()
-		nm.Name = node.Name()
 		nm.AllCaps = ms.lastCapSet
 	}
 
diff --git a/ipn/ipnlocal/local.go b/ipn/ipnlocal/local.go
index 41d110400..48d6995aa 100644
--- a/ipn/ipnlocal/local.go
+++ b/ipn/ipnlocal/local.go
@@ -1295,7 +1295,7 @@ func (b *LocalBackend) UpdateStatus(sb *ipnstate.StatusBuilder) {
 			if hi := nm.SelfNode.Hostinfo(); hi.Valid() {
 				ss.HostName = hi.Hostname()
 			}
-			ss.DNSName = nm.Name
+			ss.DNSName = nm.SelfName()
 			ss.UserID = nm.User()
 			if sn := nm.SelfNode; sn.Valid() {
 				peerStatusFromNode(ss, sn)
@@ -1611,7 +1611,7 @@ func (b *LocalBackend) SetControlClientStatus(c controlclient.Client, st control
 	keyExpiryExtended := false
 	if st.NetMap != nil {
 		wasExpired := b.keyExpired
-		isExpired := !st.NetMap.Expiry.IsZero() && st.NetMap.Expiry.Before(b.clock.Now())
+		isExpired := !st.NetMap.SelfKeyExpiry().IsZero() && st.NetMap.SelfKeyExpiry().Before(b.clock.Now())
 		if wasExpired && !isExpired {
 			keyExpiryExtended = true
 		}
diff --git a/ipn/ipnlocal/node_backend.go b/ipn/ipnlocal/node_backend.go
index dbe23e4d5..3c2e88246 100644
--- a/ipn/ipnlocal/node_backend.go
+++ b/ipn/ipnlocal/node_backend.go
@@ -747,7 +747,7 @@ func dnsConfigForNetmap(nm *netmap.NetworkMap, peers map[tailcfg.NodeID]tailcfg.
 		}
 		dcfg.Hosts[fqdn] = ips
 	}
-	set(nm.Name, nm.GetAddresses())
+	set(nm.SelfName(), nm.GetAddresses())
 	for _, peer := range peers {
 		set(peer.Name(), peer.Addresses())
 	}
diff --git a/net/tsdial/dnsmap.go b/net/tsdial/dnsmap.go
index 2ef1cb1f1..37fedd14c 100644
--- a/net/tsdial/dnsmap.go
+++ b/net/tsdial/dnsmap.go
@@ -36,11 +36,11 @@ func dnsMapFromNetworkMap(nm *netmap.NetworkMap) dnsMap {
 	suffix := nm.MagicDNSSuffix()
 	have4 := false
 	addrs := nm.GetAddresses()
-	if nm.Name != "" && addrs.Len() > 0 {
+	if name := nm.SelfName(); name != "" && addrs.Len() > 0 {
 		ip := addrs.At(0).Addr()
-		ret[canonMapKey(nm.Name)] = ip
-		if dnsname.HasSuffix(nm.Name, suffix) {
-			ret[canonMapKey(dnsname.TrimSuffix(nm.Name, suffix))] = ip
+		ret[canonMapKey(name)] = ip
+		if dnsname.HasSuffix(name, suffix) {
+			ret[canonMapKey(dnsname.TrimSuffix(name, suffix))] = ip
 		}
 		for _, p := range addrs.All() {
 			if p.Addr().Is4() {
diff --git a/types/netmap/netmap.go b/types/netmap/netmap.go
index cc6bec1db..d39eb64b5 100644
--- a/types/netmap/netmap.go
+++ b/types/netmap/netmap.go
@@ -30,10 +30,6 @@ type NetworkMap struct {
 	AllCaps    set.Set[tailcfg.NodeCapability] // set version of SelfNode.Capabilities + SelfNode.CapMap
 	NodeKey    key.NodePublic
 	PrivateKey key.NodePrivate
-	Expiry     time.Time
-	// Name is the DNS name assigned to this node.
-	// It is the MapResponse.Node.Name value and ends with a period.
-	Name string
 
 	MachineKey key.MachinePublic
 
@@ -236,10 +232,25 @@ func MagicDNSSuffixOfNodeName(nodeName string) string {
 //
 // It will neither start nor end with a period.
 func (nm *NetworkMap) MagicDNSSuffix() string {
-	if nm == nil {
+	return MagicDNSSuffixOfNodeName(nm.SelfName())
+}
+
+// SelfName returns nm.SelfNode.Name, or the empty string
+// if nm is nil or nm.SelfNode is invalid.
+func (nm *NetworkMap) SelfName() string {
+	if nm == nil || !nm.SelfNode.Valid() {
 		return ""
 	}
-	return MagicDNSSuffixOfNodeName(nm.Name)
+	return nm.SelfNode.Name()
+}
+
+// SelfKeyExpiry returns nm.SelfNode.KeyExpiry, or the zero
+// value if nil or nm.SelfNode is invalid.
+func (nm *NetworkMap) SelfKeyExpiry() time.Time {
+	if nm == nil || !nm.SelfNode.Valid() {
+		return time.Time{}
+	}
+	return nm.SelfNode.KeyExpiry()
 }
 
 // DomainName returns the name of the NetworkMap's