tunnel: defer startup until tcp configuration is set

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

2 files changed, 31 insertions, 7 deletions

diff --git a/tunnel/interfacewatcher.go b/tunnel/interfacewatcher.go
index 5ca2c69d..f3dbc46a 100644
--- a/tunnel/interfacewatcher.go
+++ b/tunnel/interfacewatcher.go
@@ -6,9 +6,11 @@
 package tunnel
 
 import (
+	"errors"
 	"fmt"
 	"log"
 	"sync"
+	"time"
 
 	"golang.org/x/sys/windows"
 	"golang.zx2c4.com/wireguard/windows/conf"
@@ -27,7 +29,8 @@ type interfaceWatcherEvent struct {
 	family winipcfg.AddressFamily
 }
 type interfaceWatcher struct {
-	errors chan interfaceWatcherError
+	errors  chan interfaceWatcherError
+	started chan winipcfg.AddressFamily
 
 	conf    *conf.Config
 	adapter *driver.Adapter
@@ -38,9 +41,11 @@ type interfaceWatcher struct {
 	changeCallbacks4        []winipcfg.ChangeCallback
 	changeCallbacks6        []winipcfg.ChangeCallback
 	storedEvents            []interfaceWatcherEvent
+	watchdog                *time.Timer
 }
 
 func (iw *interfaceWatcher) setup(family winipcfg.AddressFamily) {
+	iw.watchdog.Stop()
 	var changeCallbacks *[]winipcfg.ChangeCallback
 	var ipversion string
 	if family == windows.AF_INET {
@@ -75,12 +80,19 @@ func (iw *interfaceWatcher) setup(family winipcfg.AddressFamily) {
 		iw.errors <- interfaceWatcherError{services.ErrorSetNetConfig, err}
 		return
 	}
+
+	iw.started <- family
 }
 
 func watchInterface() (*interfaceWatcher, error) {
 	iw := &interfaceWatcher{
-		errors: make(chan interfaceWatcherError, 2),
+		errors:  make(chan interfaceWatcherError, 2),
+		started: make(chan winipcfg.AddressFamily, 4),
 	}
+	iw.watchdog = time.AfterFunc(time.Duration(1<<63-1), func() {
+		iw.errors <- interfaceWatcherError{services.ErrorCreateNetworkAdapter, errors.New("TCP/IP interface for adapter did not appear after one minute")}
+	})
+	iw.watchdog.Stop()
 	var err error
 	iw.interfaceChangeCallback, err = winipcfg.RegisterInterfaceChangeCallback(func(notificationType winipcfg.MibNotificationType, iface *winipcfg.MibIPInterfaceRow) {
 		iw.setupMutex.Lock()
@@ -119,6 +131,7 @@ func watchInterface() (*interfaceWatcher, error) {
 func (iw *interfaceWatcher) Configure(adapter *driver.Adapter, conf *conf.Config, luid winipcfg.LUID) {
 	iw.setupMutex.Lock()
 	defer iw.setupMutex.Unlock()
+	iw.watchdog.Reset(time.Minute)
 
 	iw.adapter, iw.conf, iw.luid = adapter, conf, luid
 	for _, event := range iw.storedEvents {
@@ -131,6 +144,7 @@ func (iw *interfaceWatcher) Configure(adapter *driver.Adapter, conf *conf.Config
 
 func (iw *interfaceWatcher) Destroy() {
 	iw.setupMutex.Lock()
+	iw.watchdog.Stop()
 	changeCallbacks4 := iw.changeCallbacks4
 	changeCallbacks6 := iw.changeCallbacks6
 	interfaceChangeCallback := iw.interfaceChangeCallback
diff --git a/tunnel/service.go b/tunnel/service.go
index 5680d0fc..24df3dfe 100644
--- a/tunnel/service.go
+++ b/tunnel/service.go
@@ -31,7 +31,8 @@ type tunnelService struct {
 }
 
 func (service *tunnelService) Execute(args []string, r <-chan svc.ChangeRequest, changes chan<- svc.Status) (svcSpecificEC bool, exitCode uint32) {
-	changes <- svc.Status{State: svc.StartPending}
+	serviceState := svc.StartPending
+	changes <- svc.Status{State: serviceState}
 
 	var watcher *interfaceWatcher
 	var adapter *driver.Adapter
@@ -46,7 +47,8 @@ func (service *tunnelService) Execute(args []string, r <-chan svc.ChangeRequest,
 		if logErr != nil {
 			log.Println(logErr)
 		}
-		changes <- svc.Status{State: svc.StopPending}
+		serviceState = svc.StopPending
+		changes <- svc.Status{State: serviceState}
 
 		stopIt := make(chan bool, 1)
 		go func() {
@@ -127,7 +129,8 @@ func (service *tunnelService) Execute(args []string, r <-chan svc.ChangeRequest,
 			 * announce that we're running before starting additional services.
 			 */
 			log.Printf("SCM locked for %v by %s, marking service as started", lockStatus.Age, lockStatus.Owner)
-			changes <- svc.Status{State: svc.Running}
+			serviceState = svc.Running
+			changes <- svc.Status{State: serviceState}
 		}
 		m.Disconnect()
 	}
@@ -214,9 +217,9 @@ func (service *tunnelService) Execute(args []string, r <-chan svc.ChangeRequest,
 		return
 	}
 
-	changes <- svc.Status{State: svc.Running, Accepts: svc.AcceptStop | svc.AcceptShutdown}
-	log.Println("Startup complete")
+	changes <- svc.Status{State: serviceState, Accepts: svc.AcceptStop | svc.AcceptShutdown}
 
+	var started bool
 	for {
 		select {
 		case c := <-r:
@@ -228,6 +231,13 @@ func (service *tunnelService) Execute(args []string, r <-chan svc.ChangeRequest,
 			default:
 				log.Printf("Unexpected service control request #%d\n", c)
 			}
+		case <-watcher.started:
+			if !started {
+				serviceState = svc.Running
+				changes <- svc.Status{State: serviceState, Accepts: svc.AcceptStop | svc.AcceptShutdown}
+				log.Println("Startup complete")
+				started = true
+			}
 		case e := <-watcher.errors:
 			serviceError, err = e.serviceError, e.err
 			return