[bug] fail gracefully on connection initialization errors

There's some corner cases that were very badly captured. On the first
place, it's confusing to quit on connection errors.

Secondly, a side-effect of aborting the initialization of the bitmask
object was a semi-random segfault when trying to access the object.

Here I pass any connection errors to the gui, but leave to the user to
quit the app. This probably will need more work when we want to
terminate the app on unrecoverable errors (no polkit, etc...), but for
now it makes the systray much more usable.

- Resolves: #465

gui/qml/FailDialog.qml

@@ -16,7 +16,11 @@ MessageDialog {
         if (ctx.loginDialog == 'true') {
             login.visible = true
         } else {
-            backend.quit()
+            // FIXME - we probably want to distinguish 
+            // fatal from recoverable errors. For the time being
+            // we can avoid quitting so that people can try reconnects if it's
+            // a network problem, it's confusing to quit the app.
+            // backend.quit()
         }
     }
 }

pkg/backend/actions.go

@@ -2,14 +2,14 @@ package backend
 
 import (
 	"log"
-	"os"
 )
 
 func startVPN() {
+	setError("")
 	err := ctx.bm.StartVPN(ctx.Provider)
 	if err != nil {
-		log.Println(err)
-		os.Exit(1)
+		log.Println("ERROR: ", err)
+		setError(err.Error())
 	}
 }
 

pkg/backend/api.go

@@ -38,6 +38,12 @@ func Login(username, password string) {
 	go ctx.updateStatus()
 }
 
+func setError(err string) {
+	ctx.Errors = err
+	go setStatus(off)
+	go ctx.updateStatus()
+}
+
 func SwitchOn() {
 	go setStatus(starting)
 	go startVPN()

pkg/backend/init.go

@@ -47,7 +47,7 @@ func checkErrors(errCh chan string) {
 
 func initializeBitmask(errCh chan string, opts *InitOpts) {
 	if ctx == nil {
-		log.Println("bug: cannot initialize bitmask, ctx is nil!")
+		log.Println("BUG: cannot initialize bitmask, ctx is nil!")
 		os.Exit(1)
 	}
 	bitmask.InitializeLogger()
@@ -63,7 +63,7 @@ func initializeBitmask(errCh chan string, opts *InitOpts) {
 
 	b, err := bitmask.InitializeBitmask(ctx.cfg)
 	if err != nil {
-		log.Println("error: cannot initialize bitmask")
+		log.Println("ERROR: cannot initialize bitmask")
 		errCh <- err.Error()
 		return
 	}
@@ -72,19 +72,18 @@ func initializeBitmask(errCh chan string, opts *InitOpts) {
 	helpers, privilege, err := b.VPNCheck()
 
 	if err != nil {
-		log.Println("error doing vpn check")
+		log.Println("ERROR: vpn check")
 		errCh <- err.Error()
 	}
 
 	if helpers == false {
-		log.Println("no helpers")
+		log.Println("ERROR: no helpers")
 		errCh <- "nohelpers"
 	}
 	if privilege == false {
-		log.Println("no polkit")
+		log.Println("ERROR: no polkit")
 		errCh <- "nopolkit"
 	}
-
 	ctx.bm = b
 }
 

pkg/bitmask/init.go

@@ -97,8 +97,10 @@ func InitializeBitmask(conf *config.Config) (Bitmask, error) {
 	if !conf.SkipLaunch {
 		err := maybeStartVPN(b, conf)
 		if err != nil {
+			// we don't want this error to avoid initialization of
+			// the bitmask object. If we cannot autostart it's not
+			// so terrible.
 			log.Println("Error starting VPN: ", err)
-			return nil, err
 		}
 	}
 	return b, nil

pkg/vpn/openvpn.go

@@ -47,7 +47,8 @@ func (b *Bitmask) StartVPN(provider string) error {
 	if !b.CanStartVPN() {
 		return errors.New("BUG: cannot start vpn")
 	}
-	return b.startOpenVPN(proxy)
+	err := b.startOpenVPN(proxy)
+	return err
 }
 
 func (b *Bitmask) CanStartVPN() bool {