all: make more tests pass/skip in airplane mode

Updates tailscale/corp#19786

Change-Id: Iedc6730fe91c627b556bff5325bdbaf7bf79d8e6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/sniproxy/sniproxy_test.go

@@ -24,6 +24,7 @@
 	"tailscale.com/tsnet"
 	"tailscale.com/tstest/integration"
 	"tailscale.com/tstest/integration/testcontrol"
+	"tailscale.com/tstest/nettest"
 	"tailscale.com/types/appctype"
 	"tailscale.com/types/ipproto"
 	"tailscale.com/types/key"
@@ -111,6 +112,7 @@ func startNode(t *testing.T, ctx context.Context, controlURL, hostname string) (
 }
 
 func TestSNIProxyWithNetmapConfig(t *testing.T) {
+	nettest.SkipIfNoNetwork(t)
 	c, controlURL := startControl(t)
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()
@@ -189,6 +191,7 @@ func TestSNIProxyWithNetmapConfig(t *testing.T) {
 }
 
 func TestSNIProxyWithFlagConfig(t *testing.T) {
+	nettest.SkipIfNoNetwork(t)
 	_, controlURL := startControl(t)
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 	defer cancel()

ipn/ipnlocal/local.go

@@ -614,6 +614,8 @@ func (b *LocalBackend) ReloadConfig() (ok bool, err error) {
 	return true, nil
 }
 
+var assumeNetworkUpdateForTest = envknob.RegisterBool("TS_ASSUME_NETWORK_UP_FOR_TEST")
+
 // pauseOrResumeControlClientLocked pauses b.cc if there is no network available
 // or if the LocalBackend is in Stopped state with a valid NetMap. In all other
 // cases, it unpauses it. It is a no-op if b.cc is nil.
@@ -624,7 +626,7 @@ func (b *LocalBackend) pauseOrResumeControlClientLocked() {
 		return
 	}
 	networkUp := b.prevIfState.AnyInterfaceUp()
-	b.cc.SetPaused((b.state == ipn.Stopped && b.netMap != nil) || (!networkUp && !testenv.InTest()))
+	b.cc.SetPaused((b.state == ipn.Stopped && b.netMap != nil) || (!networkUp && !testenv.InTest() && !assumeNetworkUpdateForTest()))
 }
 
 // linkChange is our network monitor callback, called whenever the network changes.

net/netcheck/netcheck.go

@@ -396,9 +396,7 @@ func makeProbePlan(dm *tailcfg.DERPMap, ifState *netmon.State, last *Report) (pl
 	have6if := ifState.HaveV6
 	have4if := ifState.HaveV4
 	plan = make(probePlan)
-	if !have4if && !have6if {
+
-		return plan
-	}
 	had4 := len(last.RegionV4Latency) > 0
 	had6 := len(last.RegionV6Latency) > 0
 	hadBoth := have6if && had4 && had6
@@ -452,10 +450,10 @@ func makeProbePlan(dm *tailcfg.DERPMap, ifState *netmon.State, last *Report) (pl
 			if try > 1 {
 				delay += time.Duration(try) * 50 * time.Millisecond
 			}
-			if do4 {
+			if do4 || n.IsTestNode() {
 				p4 = append(p4, probe{delay: delay, node: n.Name, proto: probeIPv4})
 			}
-			if do6 {
+			if do6 || n.IsTestNode() {
 				p6 = append(p6, probe{delay: delay, node: n.Name, proto: probeIPv6})
 			}
 		}
@@ -478,10 +476,10 @@ func makeProbePlanInitial(dm *tailcfg.DERPMap, ifState *netmon.State) (plan prob
 		for try := 0; try < 3; try++ {
 			n := reg.Nodes[try%len(reg.Nodes)]
 			delay := time.Duration(try) * defaultInitialRetransmitTime
-			if ifState.HaveV4 && nodeMight4(n) {
+			if ifState.HaveV4 && nodeMight4(n) || n.IsTestNode() {
 				p4 = append(p4, probe{delay: delay, node: n.Name, proto: probeIPv4})
 			}
-			if ifState.HaveV6 && nodeMight6(n) {
+			if ifState.HaveV6 && nodeMight6(n) || n.IsTestNode() {
 				p6 = append(p6, probe{delay: delay, node: n.Name, proto: probeIPv6})
 			}
 		}

net/netcheck/netcheck_test.go

@@ -23,6 +23,7 @@
 	"tailscale.com/net/stun/stuntest"
 	"tailscale.com/tailcfg"
 	"tailscale.com/tstest"
+	"tailscale.com/tstest/nettest"
 )
 
 func TestHairpinSTUN(t *testing.T) {
@@ -882,6 +883,8 @@ func TestSortRegions(t *testing.T) {
 }
 
 func TestNoCaptivePortalWhenUDP(t *testing.T) {
+	nettest.SkipIfNoNetwork(t) // empirically. not sure why.
+
 	// Override noRedirectClient to handle the /generate_204 endpoint
 	var generate204Called atomic.Bool
 	tr := RoundTripFunc(func(req *http.Request) *http.Response {
@@ -934,6 +937,7 @@ func (f RoundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
 }
 
 func TestNodeAddrResolve(t *testing.T) {
+	nettest.SkipIfNoNetwork(t)
 	c := &Client{
 		Logf:        t.Logf,
 		UseDNSCache: true,

net/stun/stuntest/stuntest.go

@@ -125,6 +125,7 @@ func DERPMapOf(stun ...string) *tailcfg.DERPMap {
 			IPv6:       ipv6,
 			STUNPort:   port,
 			STUNOnly:   true,
+			STUNTestIP: host,
 		}
 		m.Regions[regionID] = &tailcfg.DERPRegion{
 			RegionID: regionID,

tailcfg/derpmap.go

@@ -183,6 +183,10 @@ type DERPNode struct {
 	CanPort80 bool `json:",omitempty"`
 }
 
+func (n *DERPNode) IsTestNode() bool {
+	return n.STUNTestIP != "" || n.IPv4 == "127.0.0.1"
+}
+
 // DotInvalid is a fake DNS TLD used in tests for an invalid hostname.
 const DotInvalid = ".invalid"
 

tstest/integration/integration_test.go

@@ -1249,6 +1249,7 @@ func (n *testNode) StartDaemonAsIPNGOOS(ipnGOOS string) *Daemon {
 		"TS_DEBUG_FAKE_GOOS="+ipnGOOS,
 		"TS_LOGS_DIR="+t.TempDir(),
 		"TS_NETCHECK_GENERATE_204_URL="+n.env.ControlServer.URL+"/generate_204",
+		"TS_ASSUME_NETWORK_UP_FOR_TEST=1", // don't pause control client in airplane mode (no wifi, etc)
 	)
 	if version.IsRace() {
 		cmd.Env = append(cmd.Env, "GORACE=halt_on_error=1")