ipn,net,tsnet,wgengine: make an eventbus mandatory where it is used (#16594)

In the components where an event bus is already plumbed through, remove the
exceptions that allow it to be omitted, and update all the tests that relied on
those workarounds execute properly.

This change applies only to the places where we're already using the bus; it
does not enforce the existence of a bus in other components (yet),

Updates #15160

Change-Id: Iebb92243caba82b5eb420c49fc3e089a77454f65
Signed-off-by: M. J. Fromberger <[email protected]>

ipn/ipnlocal/dnsconfig_test.go

@@ -377,7 +377,7 @@ func peersMap(s []tailcfg.NodeView) map[tailcfg.NodeID]tailcfg.NodeView {
 }
 
 func TestAllowExitNodeDNSProxyToServeName(t *testing.T) {
-	b := &LocalBackend{}
+	b := newTestLocalBackend(t)
 	if b.allowExitNodeDNSProxyToServeName("google.com") {
 		t.Fatal("unexpected true on backend with nil NetMap")
 	}

ipn/ipnlocal/local.go

@@ -99,7 +99,6 @@ import (
 	"tailscale.com/util/clientmetric"
 	"tailscale.com/util/deephash"
 	"tailscale.com/util/dnsname"
-	"tailscale.com/util/eventbus"
 	"tailscale.com/util/goroutines"
 	"tailscale.com/util/httpm"
 	"tailscale.com/util/mak"
@@ -618,15 +617,7 @@ func (b *LocalBackend) currentNode() *nodeBackend {
 	if v := b.currentNodeAtomic.Load(); v != nil || !testenv.InTest() {
 		return v
 	}
-	// Auto-init [nodeBackend] in tests for LocalBackend created without the
-	// NewLocalBackend() constructor. Same reasoning for checking b.sys.
-	var bus *eventbus.Bus
-	if b.sys == nil {
-		bus = eventbus.New()
-	} else {
-		bus = b.sys.Bus.Get()
-	}
-	v := newNodeBackend(cmp.Or(b.ctx, context.Background()), bus)
+	v := newNodeBackend(cmp.Or(b.ctx, context.Background()), b.sys.Bus.Get())
 	if b.currentNodeAtomic.CompareAndSwap(nil, v) {
 		v.ready()
 	}

ipn/ipnlocal/local_test.go

@@ -463,6 +463,7 @@ func newTestLocalBackendWithSys(t testing.TB, sys *tsd.System) *LocalBackend {
 	var logf logger.Logf = logger.Discard
 	if _, ok := sys.StateStore.GetOK(); !ok {
 		sys.Set(new(mem.Store))
+		t.Log("Added memory store for testing")
 	}
 	if _, ok := sys.Engine.GetOK(); !ok {
 		eng, err := wgengine.NewFakeUserspaceEngine(logf, sys.Set, sys.HealthTracker(), sys.UserMetricsRegistry(), sys.Bus.Get())
@@ -471,6 +472,11 @@ func newTestLocalBackendWithSys(t testing.TB, sys *tsd.System) *LocalBackend {
 		}
 		t.Cleanup(eng.Close)
 		sys.Set(eng)
+		t.Log("Added fake userspace engine for testing")
+	}
+	if _, ok := sys.Dialer.GetOK(); !ok {
+		sys.Set(tsdial.NewDialer(netmon.NewStatic()))
+		t.Log("Added static dialer for testing")
 	}
 	lb, err := NewLocalBackend(logf, logid.PublicID{}, sys, 0)
 	if err != nil {

ipn/ipnlocal/network-lock_test.go

@@ -28,6 +28,7 @@ import (
 	"tailscale.com/net/tsdial"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tka"
+	"tailscale.com/tsd"
 	"tailscale.com/types/key"
 	"tailscale.com/types/netmap"
 	"tailscale.com/types/persist"
@@ -935,18 +936,21 @@ func TestTKAForceDisable(t *testing.T) {
 	defer ts.Close()
 
 	cc := fakeControlClient(t, client)
-	b := LocalBackend{
-		varRoot: temp,
-		cc:      cc,
-		ccAuto:  cc,
-		logf:    t.Logf,
-		tka: &tkaState{
-			authority: authority,
-			storage:   chonk,
-		},
-		pm:    pm,
-		store: pm.Store(),
+	sys := tsd.NewSystem()
+	sys.Set(pm.Store())
+
+	b := newTestLocalBackendWithSys(t, sys)
+	b.SetVarRoot(temp)
+	b.SetControlClientGetterForTesting(func(controlclient.Options) (controlclient.Client, error) {
+		return cc, nil
+	})
+	b.mu.Lock()
+	b.tka = &tkaState{
+		authority: authority,
+		storage:   chonk,
 	}
+	b.pm = pm
+	b.mu.Unlock()
 
 	if err := b.NetworkLockForceLocalDisable(); err != nil {
 		t.Fatalf("NetworkLockForceLocalDisable() failed: %v", err)

ipn/ipnlocal/peerapi_test.go

@@ -21,10 +21,10 @@ import (
 	"tailscale.com/ipn"
 	"tailscale.com/ipn/store/mem"
 	"tailscale.com/tailcfg"
+	"tailscale.com/tsd"
 	"tailscale.com/tstest"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/netmap"
-	"tailscale.com/util/eventbus"
 	"tailscale.com/util/must"
 	"tailscale.com/util/usermetric"
 	"tailscale.com/wgengine"
@@ -156,10 +156,9 @@ func TestHandlePeerAPI(t *testing.T) {
 				selfNode.CapMap = tailcfg.NodeCapMap{tailcfg.CapabilityDebug: nil}
 			}
 			var e peerAPITestEnv
-			lb := &LocalBackend{
-				logf:  e.logBuf.Logf,
-				clock: &tstest.Clock{},
-			}
+			lb := newTestLocalBackend(t)
+			lb.logf = e.logBuf.Logf
+			lb.clock = &tstest.Clock{}
 			lb.currentNode().SetNetMap(&netmap.NetworkMap{SelfNode: selfNode.View()})
 			e.ph = &peerAPIHandler{
 				isSelf:   tt.isSelf,
@@ -195,20 +194,20 @@ func TestPeerAPIReplyToDNSQueries(t *testing.T) {
 	h.isSelf = false
 	h.remoteAddr = netip.MustParseAddrPort("100.150.151.152:12345")
 
-	bus := eventbus.New()
-	defer bus.Close()
+	sys := tsd.NewSystem()
+	t.Cleanup(sys.Bus.Get().Close)
 
 	ht := new(health.Tracker)
-	reg := new(usermetric.Registry)
-	eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, bus)
 	pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ht))
-	h.ps = &peerAPIServer{
-		b: &LocalBackend{
-			e:     eng,
-			pm:    pm,
-			store: pm.Store(),
-		},
-	}
+	reg := new(usermetric.Registry)
+	eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, sys.Bus.Get(), sys.Set)
+	sys.Set(pm.Store())
+	sys.Set(eng)
+
+	b := newTestLocalBackendWithSys(t, sys)
+	b.pm = pm
+
+	h.ps = &peerAPIServer{b: b}
 	if h.ps.b.OfferingExitNode() {
 		t.Fatal("unexpectedly offering exit node")
 	}
@@ -250,12 +249,12 @@ func TestPeerAPIPrettyReplyCNAME(t *testing.T) {
 		var h peerAPIHandler
 		h.remoteAddr = netip.MustParseAddrPort("100.150.151.152:12345")
 
-		bus := eventbus.New()
-		defer bus.Close()
+		sys := tsd.NewSystem()
+		t.Cleanup(sys.Bus.Get().Close)
 
 		ht := new(health.Tracker)
 		reg := new(usermetric.Registry)
-		eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, bus)
+		eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, sys.Bus.Get(), sys.Set)
 		pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ht))
 		var a *appc.AppConnector
 		if shouldStore {
@@ -263,16 +262,14 @@ func TestPeerAPIPrettyReplyCNAME(t *testing.T) {
 		} else {
 			a = appc.NewAppConnector(t.Logf, &appctest.RouteCollector{}, nil, nil)
 		}
-		h.ps = &peerAPIServer{
-			b: &LocalBackend{
-				e:     eng,
-				pm:    pm,
-				store: pm.Store(),
-				// configure as an app connector just to enable the API.
-				appConnector: a,
-			},
-		}
+		sys.Set(pm.Store())
+		sys.Set(eng)
 
+		b := newTestLocalBackendWithSys(t, sys)
+		b.pm = pm
+		b.appConnector = a // configure as an app connector just to enable the API.
+
+		h.ps = &peerAPIServer{b: b}
 		h.ps.resolver = &fakeResolver{build: func(b *dnsmessage.Builder) {
 			b.CNAMEResource(
 				dnsmessage.ResourceHeader{
@@ -326,27 +323,29 @@ func TestPeerAPIReplyToDNSQueriesAreObserved(t *testing.T) {
 		var h peerAPIHandler
 		h.remoteAddr = netip.MustParseAddrPort("100.150.151.152:12345")
 
-		bus := eventbus.New()
-		defer bus.Close()
+		sys := tsd.NewSystem()
+		t.Cleanup(sys.Bus.Get().Close)
+
 		rc := &appctest.RouteCollector{}
 		ht := new(health.Tracker)
-		reg := new(usermetric.Registry)
-		eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, bus)
 		pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ht))
+
+		reg := new(usermetric.Registry)
+		eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, sys.Bus.Get(), sys.Set)
 		var a *appc.AppConnector
 		if shouldStore {
 			a = appc.NewAppConnector(t.Logf, rc, &appc.RouteInfo{}, fakeStoreRoutes)
 		} else {
 			a = appc.NewAppConnector(t.Logf, rc, nil, nil)
 		}
-		h.ps = &peerAPIServer{
-			b: &LocalBackend{
-				e:            eng,
-				pm:           pm,
-				store:        pm.Store(),
-				appConnector: a,
-			},
-		}
+		sys.Set(pm.Store())
+		sys.Set(eng)
+
+		b := newTestLocalBackendWithSys(t, sys)
+		b.pm = pm
+		b.appConnector = a
+
+		h.ps = &peerAPIServer{b: b}
 		h.ps.b.appConnector.UpdateDomains([]string{"example.com"})
 		h.ps.b.appConnector.Wait(ctx)
 
@@ -393,12 +392,13 @@ func TestPeerAPIReplyToDNSQueriesAreObservedWithCNAMEFlattening(t *testing.T) {
 		var h peerAPIHandler
 		h.remoteAddr = netip.MustParseAddrPort("100.150.151.152:12345")
 
-		bus := eventbus.New()
-		defer bus.Close()
+		sys := tsd.NewSystem()
+		t.Cleanup(sys.Bus.Get().Close)
+
 		ht := new(health.Tracker)
 		reg := new(usermetric.Registry)
 		rc := &appctest.RouteCollector{}
-		eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, bus)
+		eng, _ := wgengine.NewFakeUserspaceEngine(logger.Discard, 0, ht, reg, sys.Bus.Get(), sys.Set)
 		pm := must.Get(newProfileManager(new(mem.Store), t.Logf, ht))
 		var a *appc.AppConnector
 		if shouldStore {
@@ -406,14 +406,14 @@ func TestPeerAPIReplyToDNSQueriesAreObservedWithCNAMEFlattening(t *testing.T) {
 		} else {
 			a = appc.NewAppConnector(t.Logf, rc, nil, nil)
 		}
-		h.ps = &peerAPIServer{
-			b: &LocalBackend{
-				e:            eng,
-				pm:           pm,
-				store:        pm.Store(),
-				appConnector: a,
-			},
-		}
+		sys.Set(pm.Store())
+		sys.Set(eng)
+
+		b := newTestLocalBackendWithSys(t, sys)
+		b.pm = pm
+		b.appConnector = a
+
+		h.ps = &peerAPIServer{b: b}
 		h.ps.b.appConnector.UpdateDomains([]string{"www.example.com"})
 		h.ps.b.appConnector.Wait(ctx)
 

net/portmapper/igd_test.go

@@ -263,16 +263,21 @@ func (d *TestIGD) handlePCPQuery(pkt []byte, src netip.AddrPort) {
 }
 
 // newTestClient configures a new test client connected to igd for mapping updates.
-// If bus != nil, update events are published to it.
-// A cleanup for the resulting client is added to t.
+// If bus == nil, a new empty event bus is constructed that is cleaned up when t exits.
+// A cleanup for the resulting client is also added to t.
 func newTestClient(t *testing.T, igd *TestIGD, bus *eventbus.Bus) *Client {
+	if bus == nil {
+		bus = eventbus.New()
+		t.Log("Created empty event bus for test client")
+		t.Cleanup(bus.Close)
+	}
 	var c *Client
 	c = NewClient(Config{
 		Logf:         tstest.WhileTestRunningLogger(t),
 		NetMon:       netmon.NewStatic(),
 		ControlKnobs: new(controlknobs.Knobs),
 		EventBus:     bus,
-		OnChange: func() {
+		OnChange: func() { // TODO(creachadair): Remove.
 			t.Logf("port map changed")
 			t.Logf("have mapping: %v", c.HaveMapping())
 		},

net/portmapper/portmapper.go

@@ -85,7 +85,7 @@ const trustServiceStillAvailableDuration = 10 * time.Minute
 
 // Client is a port mapping client.
 type Client struct {
-	// The following two fields must either both be nil, or both non-nil.
+	// The following two fields must both be non-nil.
 	// Both are immutable after construction.
 	pubClient *eventbus.Client
 	updates   *eventbus.Publisher[Mapping]
@@ -238,8 +238,11 @@ type Config struct {
 // NewClient constructs a new portmapping [Client] from c. It will panic if any
 // required parameters are omitted.
 func NewClient(c Config) *Client {
-	if c.NetMon == nil {
-		panic("nil netMon")
+	switch {
+	case c.NetMon == nil:
+		panic("nil NetMon")
+	case c.EventBus == nil:
+		panic("nil EventBus")
 	}
 	ret := &Client{
 		logf:         c.Logf,
@@ -248,10 +251,8 @@ func NewClient(c Config) *Client {
 		onChange:     c.OnChange,
 		controlKnobs: c.ControlKnobs,
 	}
-	if c.EventBus != nil {
-		ret.pubClient = c.EventBus.Client("portmapper")
-		ret.updates = eventbus.Publish[Mapping](ret.pubClient)
-	}
+	ret.pubClient = c.EventBus.Client("portmapper")
+	ret.updates = eventbus.Publish[Mapping](ret.pubClient)
 	if ret.logf == nil {
 		ret.logf = logger.Discard
 	}
@@ -286,10 +287,9 @@ func (c *Client) Close() error {
 	}
 	c.closed = true
 	c.invalidateMappingsLocked(true)
-	if c.updates != nil {
-		c.updates.Close()
-		c.pubClient.Close()
-	}
+	c.updates.Close()
+	c.pubClient.Close()
+
 	// TODO: close some future ever-listening UDP socket(s),
 	// waiting for multicast announcements from router.
 	return nil
@@ -515,14 +515,14 @@ func (c *Client) createMapping() {
 		// the control flow to eliminate that possibility. Meanwhile, this
 		// mitigates a panic downstream, cf. #16662.
 	}
-	if c.updates != nil {
-		c.updates.Publish(Mapping{
-			External:  mapping.External(),
-			Type:      mapping.MappingType(),
-			GoodUntil: mapping.GoodUntil(),
-		})
-	}
-	if c.onChange != nil && c.pubClient == nil {
+	c.updates.Publish(Mapping{
+		External:  mapping.External(),
+		Type:      mapping.MappingType(),
+		GoodUntil: mapping.GoodUntil(),
+	})
+	// TODO(creachadair): Remove this entirely once there are no longer any
+	// places where the callback is set.
+	if c.onChange != nil {
 		go c.onChange()
 	}
 }

net/udprelay/server.go

@@ -291,6 +291,9 @@ func NewServer(logf logger.Logf, port int, overrideAddrs []netip.Addr) (s *Serve
 		s.vniPool = append(s.vniPool, uint32(i))
 	}
 
+	// TODO(creachadair): Find a way to plumb this in during initialization.
+	// As-written, messages published here will not be seen by other components
+	// in a running client.
 	bus := eventbus.New()
 	s.bus = bus
 	netMon, err := netmon.New(s.bus, logf)

tsnet/tsnet.go

@@ -435,10 +435,7 @@ func (s *Server) Close() error {
 		ln.closeLocked()
 	}
 	wg.Wait()
-
-	if bus := s.sys.Bus.Get(); bus != nil {
-		bus.Close()
-	}
+	s.sys.Bus.Get().Close()
 	s.closed = true
 	return nil
 }

wgengine/magicsock/magicsock.go

@@ -715,8 +715,11 @@ func (c *Conn) Synchronize() {
 // As the set of possible endpoints for a Conn changes, the
 // callback opts.EndpointsFunc is called.
 func NewConn(opts Options) (*Conn, error) {
-	if opts.NetMon == nil {
+	switch {
+	case opts.NetMon == nil:
 		return nil, errors.New("magicsock.Options.NetMon must be non-nil")
+	case opts.EventBus == nil:
+		return nil, errors.New("magicsock.Options.EventBus must be non-nil")
 	}
 
 	c := newConn(opts.logf())
@@ -729,22 +732,20 @@ func NewConn(opts Options) (*Conn, error) {
 	c.testOnlyPacketListener = opts.TestOnlyPacketListener
 	c.noteRecvActivity = opts.NoteRecvActivity
 
-	if c.eventBus != nil {
-		c.eventClient = c.eventBus.Client("magicsock.Conn")
-
-		// Subscribe calls must return before NewConn otherwise published
-		// events can be missed.
-		c.pmSub = eventbus.Subscribe[portmapper.Mapping](c.eventClient)
-		c.filterSub = eventbus.Subscribe[FilterUpdate](c.eventClient)
-		c.nodeViewsSub = eventbus.Subscribe[NodeViewsUpdate](c.eventClient)
-		c.nodeMutsSub = eventbus.Subscribe[NodeMutationsUpdate](c.eventClient)
-		c.syncSub = eventbus.Subscribe[syncPoint](c.eventClient)
-		c.syncPub = eventbus.Publish[syncPoint](c.eventClient)
-		c.allocRelayEndpointPub = eventbus.Publish[UDPRelayAllocReq](c.eventClient)
-		c.allocRelayEndpointSub = eventbus.Subscribe[UDPRelayAllocResp](c.eventClient)
-		c.subsDoneCh = make(chan struct{})
-		go c.consumeEventbusTopics()
-	}
+	c.eventClient = c.eventBus.Client("magicsock.Conn")
+
+	// Subscribe calls must return before NewConn otherwise published
+	// events can be missed.
+	c.pmSub = eventbus.Subscribe[portmapper.Mapping](c.eventClient)
+	c.filterSub = eventbus.Subscribe[FilterUpdate](c.eventClient)
+	c.nodeViewsSub = eventbus.Subscribe[NodeViewsUpdate](c.eventClient)
+	c.nodeMutsSub = eventbus.Subscribe[NodeMutationsUpdate](c.eventClient)
+	c.syncSub = eventbus.Subscribe[syncPoint](c.eventClient)
+	c.syncPub = eventbus.Publish[syncPoint](c.eventClient)
+	c.allocRelayEndpointPub = eventbus.Publish[UDPRelayAllocReq](c.eventClient)
+	c.allocRelayEndpointSub = eventbus.Subscribe[UDPRelayAllocResp](c.eventClient)
+	c.subsDoneCh = make(chan struct{})
+	go c.consumeEventbusTopics()
 
 	// Don't log the same log messages possibly every few seconds in our
 	// portmapper.
@@ -3327,10 +3328,8 @@ func (c *Conn) Close() error {
 	//     deadlock with c.Close().
 	//  2. Conn.consumeEventbusTopics event handlers may not guard against
 	//     undesirable post/in-progress Conn.Close() behaviors.
-	if c.eventClient != nil {
-		c.eventClient.Close()
-		<-c.subsDoneCh
-	}
+	c.eventClient.Close()
+	<-c.subsDoneCh
 
 	c.mu.Lock()
 	defer c.mu.Unlock()

wgengine/magicsock/magicsock_test.go

@@ -179,7 +179,7 @@ func newMagicStackWithKey(t testing.TB, logf logger.Logf, l nettype.PacketListen
 	t.Helper()
 
 	bus := eventbus.New()
-	defer bus.Close()
+	t.Cleanup(bus.Close)
 
 	netMon, err := netmon.New(bus, logf)
 	if err != nil {
@@ -191,6 +191,7 @@ func newMagicStackWithKey(t testing.TB, logf logger.Logf, l nettype.PacketListen
 	epCh := make(chan []tailcfg.Endpoint, 100) // arbitrary
 	conn, err := NewConn(Options{
 		NetMon:                 netMon,
+		EventBus:               bus,
 		Metrics:                &reg,
 		Logf:                   logf,
 		HealthTracker:          ht,
@@ -406,7 +407,7 @@ func TestNewConn(t *testing.T) {
 	}
 
 	bus := eventbus.New()
-	defer bus.Close()
+	t.Cleanup(bus.Close)
 
 	netMon, err := netmon.New(bus, logger.WithPrefix(t.Logf, "... netmon: "))
 	if err != nil {
@@ -424,6 +425,7 @@ func TestNewConn(t *testing.T) {
 		EndpointsFunc:     epFunc,
 		Logf:              t.Logf,
 		NetMon:            netMon,
+		EventBus:          bus,
 		Metrics:           new(usermetric.Registry),
 	})
 	if err != nil {
@@ -542,7 +544,7 @@ func TestDeviceStartStop(t *testing.T) {
 	tstest.ResourceCheck(t)
 
 	bus := eventbus.New()
-	defer bus.Close()
+	t.Cleanup(bus.Close)
 
 	netMon, err := netmon.New(bus, logger.WithPrefix(t.Logf, "... netmon: "))
 	if err != nil {
@@ -554,6 +556,7 @@ func TestDeviceStartStop(t *testing.T) {
 		EndpointsFunc: func(eps []tailcfg.Endpoint) {},
 		Logf:          t.Logf,
 		NetMon:        netMon,
+		EventBus:      bus,
 		Metrics:       new(usermetric.Registry),
 	})
 	if err != nil {
@@ -1349,7 +1352,7 @@ func newTestConn(t testing.TB) *Conn {
 	port := pickPort(t)
 
 	bus := eventbus.New()
-	defer bus.Close()
+	t.Cleanup(bus.Close)
 
 	netMon, err := netmon.New(bus, logger.WithPrefix(t.Logf, "... netmon: "))
 	if err != nil {
@@ -1359,6 +1362,7 @@ func newTestConn(t testing.TB) *Conn {
 
 	conn, err := NewConn(Options{
 		NetMon:                 netMon,
+		EventBus:               bus,
 		HealthTracker:          new(health.Tracker),
 		Metrics:                new(usermetric.Registry),
 		DisablePortMapper:      true,
@@ -3147,6 +3151,7 @@ func TestNetworkDownSendErrors(t *testing.T) {
 		Logf:              t.Logf,
 		NetMon:            netMon,
 		Metrics:           reg,
+		EventBus:          bus,
 	}))
 	defer conn.Close()