Reconnect if default route disappears while connecting on macOS

talpid-core/src/tunnel_state_machine/connecting_state.rs

@@ -599,7 +599,7 @@ fn should_retry(error: &tunnel::Error, retry_attempt: u32) -> bool {
             TunnelError::BypassError(_),
         )) => true,
 
-        #[cfg(windows)]
+        #[cfg(any(target_os = "windows", target_os = "macos"))]
         tunnel::Error::WireguardTunnelMonitoringError(Error::SetupRoutingError(error)) => {
             is_recoverable_routing_error(error)
         }
@@ -624,6 +624,18 @@ fn is_recoverable_routing_error(error: &talpid_routing::Error) -> bool {
     matches!(error, talpid_routing::Error::AddRoutesFailed(_))
 }
 
+#[cfg(target_os = "macos")]
+fn is_recoverable_routing_error(error: &talpid_routing::Error) -> bool {
+    // If the default route disappears while connecting but before it is caught by the offline
+    // monitor, then the gateway will be unreachable. In this case, just retry.
+    matches!(
+        error,
+        talpid_routing::Error::PlatformError(talpid_routing::PlatformError::AddRoute(
+            talpid_routing::RouteError::Unreachable,
+        ))
+    )
+}
+
 impl TunnelState for ConnectingState {
     fn handle_event(
         mut self: Box<Self>,

talpid-routing/src/lib.rs

@@ -23,7 +23,7 @@ mod imp;
 use netlink_packet_route::rtnl::constants::RT_TABLE_MAIN;
 
 #[cfg(target_os = "macos")]
-pub use imp::{DefaultRouteEvent, PlatformError};
+pub use imp::{imp::RouteError, DefaultRouteEvent, PlatformError};
 
 pub use imp::{Error, RouteManager};
 

talpid-routing/src/unix/macos/mod.rs

@@ -23,6 +23,8 @@ mod interface;
 mod routing_socket;
 mod watch;
 
+pub use watch::Error as RouteError;
+
 pub type Result<T> = std::result::Result<T, Error>;
 
 const BURST_BUFFER_PERIOD: Duration = Duration::from_millis(200);
@@ -36,7 +38,7 @@ pub enum Error {
     #[error(display = "Error occurred when interfacing with the routing table")]
     RoutingTable(#[error(source)] watch::Error),
 
-    /// Failed to remvoe route
+    /// Failed to remove route
     #[error(display = "Error occurred when deleting a route")]
     DeleteRoute(#[error(source)] watch::Error),
 

talpid-routing/src/unix/macos/watch.rs

@@ -6,20 +6,28 @@ use std::io;
 
 type Result<T> = std::result::Result<T, Error>;
 
+/// Errors that can occur for a PF_ROUTE socket
 #[derive(Debug, err_derive::Error)]
 pub enum Error {
+    /// Generic routing socket error
     #[error(display = "Routing socket error: {}", _0)]
     RoutingSocket(routing_socket::Error),
+    /// Failed to parse route message
     #[error(display = "Invalid message")]
     InvalidMessage(data::Error),
+    /// Failed to send route message
     #[error(display = "Failed to send routing message")]
     Send(routing_socket::Error),
+    /// Received unexpected response to route message
     #[error(display = "Unexpected message type")]
     UnexpectedMessageType(RouteSocketMessage, MessageType),
+    /// Route not found
     #[error(display = "Route not found")]
     RouteNotFound,
+    /// No route to destination
     #[error(display = "Destination unreachable")]
     Unreachable,
+    /// Failed to delete route
     #[error(display = "Failed to delete a route")]
     Deletion(RouteMessage),
 }