Return boolean to indicate if tunnel is up

Allows the tunnel state machine to determine if it is blocking
connections when entering the error state.

2 files changed, 8 insertions, 4 deletions

diff --git a/android/src/main/kotlin/net/mullvad/talpid/TalpidVpnService.kt b/android/src/main/kotlin/net/mullvad/talpid/TalpidVpnService.kt
index 93c7f32c36..a0dfd029f2 100644
--- a/android/src/main/kotlin/net/mullvad/talpid/TalpidVpnService.kt
+++ b/android/src/main/kotlin/net/mullvad/talpid/TalpidVpnService.kt
@@ -55,11 +55,13 @@ open class TalpidVpnService : VpnService() {
         }
     }
 
-    fun createTunIfClosed() {
+    fun createTunIfClosed(): Boolean {
         synchronized(this) {
             if (activeTunDevice == null) {
                 activeTunDevice = createTun(currentTunConfig)
             }
+
+            return activeTunDevice?.let { tunFd -> tunFd > 0 } ?: false
         }
     }
 
diff --git a/talpid-core/src/tunnel/tun_provider/android/mod.rs b/talpid-core/src/tunnel/tun_provider/android/mod.rs
index e4e8f4fbac..c744ca96fa 100644
--- a/talpid-core/src/tunnel/tun_provider/android/mod.rs
+++ b/talpid-core/src/tunnel/tun_provider/android/mod.rs
@@ -7,6 +7,7 @@ use jnix::{
     jni::{
         objects::{GlobalRef, JValue},
         signature::{JavaType, Primitive},
+        sys::JNI_FALSE,
         JavaVM,
     },
     IntoJava, JnixEnv,
@@ -133,13 +134,14 @@ impl AndroidTunProvider {
     pub fn create_tun_if_closed(&mut self) -> Result<(), Error> {
         let result = self.call_method(
             "createTunIfClosed",
-            "()V",
-            JavaType::Primitive(Primitive::Void),
+            "()Z",
+            JavaType::Primitive(Primitive::Boolean),
             &[],
         )?;
 
         match result {
-            JValue::Void => Ok(()),
+            JValue::Bool(JNI_FALSE) => Err(Error::TunnelDeviceError),
+            JValue::Bool(_) => Ok(()),
             value => Err(Error::InvalidMethodResult(
                 "createTunIfClosed",
                 format!("{:?}", value),