tailcfg: add Hostinfo.Userspace{,Router} bits

Change-Id: Iad47f904872f2df146c1f63945f79cfddeac7fe8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/ipnlocal/local.go

@@ -955,6 +955,8 @@ func (b *LocalBackend) Start(opts ipn.Options) error {
 	hostinfo := hostinfo.New()
 	hostinfo.BackendLogID = b.backendLogID
 	hostinfo.FrontendLogID = opts.FrontendLogID
+	hostinfo.Userspace.Set(wgengine.IsNetstack(b.e))
+	hostinfo.UserspaceRouter.Set(wgengine.IsNetstackRouter(b.e))
 
 	if b.cc != nil {
 		// TODO(apenwarr): avoid the need to reinit controlclient.

tailcfg/tailcfg.go

@@ -484,6 +484,8 @@ type Hostinfo struct {
 	NetInfo         *NetInfo       `json:",omitempty"`
 	SSH_HostKeys    []string       `json:"sshHostKeys,omitempty"` // if advertised
 	Cloud           string         `json:",omitempty"`
+	Userspace       opt.Bool       `json:",omitempty"` // if the client is running in userspace (netstack) mode
+	UserspaceRouter opt.Bool       `json:",omitempty"` // if the client's subnet router is running in userspace (netstack) mode
 
 	// NOTE: any new fields containing pointers in this type
 	//       require changes to Hostinfo.Equal.

tailcfg/tailcfg_clone.go

@@ -134,6 +134,8 @@ var _HostinfoCloneNeedsRegeneration = Hostinfo(struct {
 	NetInfo         *NetInfo
 	SSH_HostKeys    []string
 	Cloud           string
+	Userspace       opt.Bool
+	UserspaceRouter opt.Bool
 }{})
 
 // Clone makes a deep copy of NetInfo.

tailcfg/tailcfg_test.go

@@ -37,6 +37,7 @@ func TestHostinfoEqual(t *testing.T) {
 		"GoArch", "GoVersion",
 		"RoutableIPs", "RequestTags",
 		"Services", "NetInfo", "SSH_HostKeys", "Cloud",
+		"Userspace", "UserspaceRouter",
 	}
 	if have := fieldsOf(reflect.TypeOf(Hostinfo{})); !reflect.DeepEqual(have, hiHandles) {
 		t.Errorf("Hostinfo.Equal check might be out of sync\nfields: %q\nhandled: %q\n",

tailcfg/tailcfg_view.go

@@ -271,6 +271,8 @@ func (v HostinfoView) Services() views.Slice[Service]    { return views.SliceOf(
 func (v HostinfoView) NetInfo() NetInfoView              { return v.ж.NetInfo.View() }
 func (v HostinfoView) SSH_HostKeys() views.Slice[string] { return views.SliceOf(v.ж.SSH_HostKeys) }
 func (v HostinfoView) Cloud() string                     { return v.ж.Cloud }
+func (v HostinfoView) Userspace() opt.Bool               { return v.ж.Userspace }
+func (v HostinfoView) UserspaceRouter() opt.Bool         { return v.ж.UserspaceRouter }
 func (v HostinfoView) Equal(v2 HostinfoView) bool        { return v.ж.Equal(v2.ж) }
 
 // A compilation failure here means this code must be regenerated, with the command at the top of this file.
@@ -294,6 +296,8 @@ var _HostinfoViewNeedsRegeneration = Hostinfo(struct {
 	NetInfo         *NetInfo
 	SSH_HostKeys    []string
 	Cloud           string
+	Userspace       opt.Bool
+	UserspaceRouter opt.Bool
 }{})
 
 // View returns a readonly view of NetInfo.