Default `pki.disconnect_invalid` to true and make it reloadable (#859)

connection_manager.go

@@ -432,7 +432,7 @@ func (n *connectionManager) isInvalidCertificate(now time.Time, hostinfo *HostIn
 		return false
 	}
 
-	if !n.intf.disconnectInvalid && err != cert.ErrBlockListed {
+	if !n.intf.disconnectInvalid.Load() && err != cert.ErrBlockListed {
 		// Block listed certificates should always be disconnected
 		return false
 	}

connection_manager_test.go

@@ -253,18 +253,18 @@ func Test_NewConnectionManagerTest_DisconnectInvalid(t *testing.T) {
 
 	lh := newTestLighthouse()
 	ifce := &Interface{
-		hostMap:           hostMap,
-		inside:            &test.NoopTun{},
-		outside:           &udp.NoopConn{},
-		firewall:          &Firewall{},
-		lightHouse:        lh,
-		handshakeManager:  NewHandshakeManager(l, hostMap, lh, &udp.NoopConn{}, defaultHandshakeConfig),
-		l:                 l,
-		disconnectInvalid: true,
-		pki:               &PKI{},
+		hostMap:          hostMap,
+		inside:           &test.NoopTun{},
+		outside:          &udp.NoopConn{},
+		firewall:         &Firewall{},
+		lightHouse:       lh,
+		handshakeManager: NewHandshakeManager(l, hostMap, lh, &udp.NoopConn{}, defaultHandshakeConfig),
+		l:                l,
+		pki:              &PKI{},
 	}
 	ifce.pki.cs.Store(cs)
 	ifce.pki.caPool.Store(ncp)
+	ifce.disconnectInvalid.Store(true)
 
 	// Create manager
 	ctx, cancel := context.WithCancel(context.Background())

examples/config.yml

@@ -11,7 +11,7 @@ pki:
   #blocklist:
   #  - c99d4e650533b92061b09918e838a5a0a6aaee21eed1d12fd937682865936c72
   # disconnect_invalid is a toggle to force a client to be disconnected if the certificate is expired or invalid.
-  #disconnect_invalid: false
+  #disconnect_invalid: true
 
 # The static host map defines a set of hosts with fixed IP addresses on the internet (or any network).
 # A host can have multiple fixed IP addresses defined here, and nebula will try each when establishing a tunnel.

interface.go

@@ -40,7 +40,6 @@ type InterfaceConfig struct {
 	routines                int
 	MessageMetrics          *MessageMetrics
 	version                 string
-	disconnectInvalid       bool
 	relayManager            *relayManager
 	punchy                  *Punchy
 
@@ -69,7 +68,7 @@ type Interface struct {
 	dropLocalBroadcast bool
 	dropMulticast      bool
 	routines           int
-	disconnectInvalid  bool
+	disconnectInvalid  atomic.Bool
 	closed             atomic.Bool
 	relayManager       *relayManager
 
@@ -176,7 +175,6 @@ func NewInterface(ctx context.Context, c *InterfaceConfig) (*Interface, error) {
 		version:            c.version,
 		writers:            make([]udp.Conn, c.routines),
 		readers:            make([]io.ReadWriteCloser, c.routines),
-		disconnectInvalid:  c.disconnectInvalid,
 		myVpnIp:            myVpnIp,
 		relayManager:       c.relayManager,
 
@@ -294,12 +292,24 @@ func (f *Interface) listenIn(reader io.ReadWriteCloser, i int) {
 func (f *Interface) RegisterConfigChangeCallbacks(c *config.C) {
 	c.RegisterReloadCallback(f.reloadFirewall)
 	c.RegisterReloadCallback(f.reloadSendRecvError)
+	c.RegisterReloadCallback(f.reloadDisconnectInvalid)
 	c.RegisterReloadCallback(f.reloadMisc)
+
 	for _, udpConn := range f.writers {
 		c.RegisterReloadCallback(udpConn.ReloadConfig)
 	}
 }
 
+func (f *Interface) reloadDisconnectInvalid(c *config.C) {
+	initial := c.InitialLoad()
+	if initial || c.HasChanged("pki.disconnect_invalid") {
+		f.disconnectInvalid.Store(c.GetBool("pki.disconnect_invalid", true))
+		if !initial {
+			f.l.Infof("pki.disconnect_invalid changed to %v", f.disconnectInvalid.Load())
+		}
+	}
+}
+
 func (f *Interface) reloadFirewall(c *config.C) {
 	//TODO: need to trigger/detect if the certificate changed too
 	if c.HasChanged("firewall") == false {

main.go

@@ -273,7 +273,6 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		routines:                routines,
 		MessageMetrics:          messageMetrics,
 		version:                 buildVersion,
-		disconnectInvalid:       c.GetBool("pki.disconnect_invalid", false),
 		relayManager:            NewRelayManager(ctx, l, hostMap, c),
 		punchy:                  punchy,
 
@@ -303,6 +302,7 @@ func Main(c *config.C, configTest bool, buildVersion string, logger *logrus.Logg
 		lightHouse.ifce = ifce
 
 		ifce.RegisterConfigChangeCallbacks(c)
+		ifce.reloadDisconnectInvalid(c)
 		ifce.reloadSendRecvError(c)
 
 		handshakeManager.f = ifce