Add env var to disable offline detection

CHANGELOG.md

@@ -26,6 +26,8 @@ Line wrap the file at 100 chars.                                              Th
 ### Added
 - Add header containing OS version to version-check API call to enable OS specific compatibility and
   vulnerability checks.
+- Add `TALPID_DISABLE_OFFLINE_MONITOR` environment variable to allow users to disable offline
+  detection.
 
 #### Android
 - Allow to configure the tunnel to use custom DNS servers.

README.md

@@ -369,6 +369,8 @@ echo "org.gradle.jvmargs=-Xmx4608M" >> ~/.gradle/gradle.properties
 * `TALPID_FORCE_USERSPACE_WIREGUARD` - Forces the daemon to use the userspace implementation of
    WireGuard on Linux.
 
+* `TALPID_DISABLE_OFFLINE_MONITOR` - Forces the daemon to always assume the host is online.
+
 
 ## Building and running the desktop Electron GUI app
 

talpid-core/src/offline/mod.rs

@@ -20,26 +20,42 @@ mod imp;
 #[path = "android.rs"]
 mod imp;
 
+lazy_static::lazy_static! {
+    /// Disables offline monitor
+    static ref FORCE_DISABLE_OFFLINE_MONITOR: bool = std::env::var("TALPID_FORCE_USERSPACE_WIREGUARD")
+        .map(|v| v != "0")
+        .unwrap_or(false);
+}
+
 pub use self::imp::Error;
 
-pub struct MonitorHandle(imp::MonitorHandle);
+pub struct MonitorHandle(Option<imp::MonitorHandle>);
 
 impl MonitorHandle {
     pub async fn is_offline(&mut self) -> bool {
-        self.0.is_offline().await
+        match self.0.as_mut() {
+            Some(monitor) => monitor.is_offline().await,
+            None => false,
+        }
     }
 }
 
 pub async fn spawn_monitor(
     sender: Weak<UnboundedSender<TunnelCommand>>,
     #[cfg(target_os = "android")] android_context: AndroidContext,
 ) -> Result<MonitorHandle, Error> {
-    Ok(MonitorHandle(
-        imp::spawn_monitor(
-            sender,
-            #[cfg(target_os = "android")]
-            android_context,
+    let monitor = if !*FORCE_DISABLE_OFFLINE_MONITOR {
+        Some(
+            imp::spawn_monitor(
+                sender,
+                #[cfg(target_os = "android")]
+                android_context,
+            )
+            .await?,
         )
-        .await?,
-    ))
+    } else {
+        None
+    };
+
+    Ok(MonitorHandle(monitor))
 }