[windows_kext] Fix minor problems

service/firewall/interception/windowskext2/kext.go

@@ -39,7 +39,11 @@ func Start() error {
 	}
 
 	// Start service and open file
-	service.Start(true)
+	err = service.Start(true)
+	if err != nil {
+		log.Errorf("failed to start service: %s", err)
+	}
+
 	kextFile, err = service.OpenFile(1024)
 	if err != nil {
 		return fmt.Errorf("failed to open driver: %w", err)

windows_kext/kextinterface/kext.go

@@ -11,6 +11,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/safing/portmaster/base/log"
 	"golang.org/x/sys/windows"
 )
 
@@ -221,7 +222,7 @@ func CreateKextService(driverName string, driverPath string) (*KextService, erro
 	// Check if there is an old service.
 	service, err := windows.OpenService(manager, &driverNameU16[0], windows.SERVICE_ALL_ACCESS)
 	if err == nil {
-		fmt.Println("kext: old driver service was found")
+		log.Warning("kext: old driver service was found")
 		oldService := &KextService{handle: service, driverName: driverName}
 		oldService.Stop(true)
 		err = oldService.Delete()
@@ -234,7 +235,7 @@ func CreateKextService(driverName string, driverPath string) (*KextService, erro
 		}
 
 		service = winInvalidHandleValue
-		fmt.Println("kext: old driver service was deleted successfully")
+		log.Warning("kext: old driver service was deleted successfully")
 	}
 
 	driverPathU16, err := syscall.UTF16FromString(driverPath)

windows_kext/kextinterface/protocol_test.go

@@ -22,6 +22,7 @@ func TestRustInfoFile(t *testing.T) {
 	for {
 		info, err := RecvInfo(file)
 		// First info should be with invalid size.
+		// This tests if invalid info data is handled properly.
 		if first {
 			if !errors.Is(err, ErrUnexpectedInfoSize) {
 				t.Errorf("unexpected error: %s\n", err)

windows_kext/protocol/src/info.rs

@@ -441,7 +441,7 @@ fn generate_test_info_file() -> Result<(), std::io::Error> {
     for _ in 0..selected.capacity() {
         selected.push(enums.choose(&mut rng).unwrap().clone());
     }
-    // Write wrong size data.
+    // Write wrong size data. To make sure that mismatches between kext and portmaster are handled properly.
     let mut info = connection_info_v6(
         1,
         2,