Document function that handles route messages on macOS

1 files changed, 15 insertions, 3 deletions

diff --git a/talpid-routing/src/unix/macos/mod.rs b/talpid-routing/src/unix/macos/mod.rs
index 7720d79d08..0780cd9c30 100644
--- a/talpid-routing/src/unix/macos/mod.rs
+++ b/talpid-routing/src/unix/macos/mod.rs
@@ -273,11 +273,23 @@ impl RouteManagerImpl {
         }
     }
 
-    /// Update routes that use the non-tunnel default interface
+    /// Handle changes to the routing table. Specifically, when a default route is added, modified,
+    /// or deleted:
+    ///
+    /// * Replace the default route with a default route for the tunnel interface (i.e., one whose
+    ///   gateway is set to the link address of the tunnel interface).
+    /// * At the same time, update the route used by non-tunnel interfaces to reach the relay/VPN
+    ///   server. The gateway of the relay route is set to the first interface in the network
+    ///   service order that has a working ifscoped default route.
+    ///
+    /// # Arguments
+    ///
+    /// * `route_is_being_deleted` - A boolean that should be set to `true` if `route` is being
+    ///   deleted. This should be `false` if the route is being modified or added.
     async fn handle_route_change(
         &mut self,
         route: data::RouteMessage,
-        is_deletion: bool,
+        route_is_being_deleted: bool,
     ) -> Result<()> {
         // Ignore routes that aren't default routes
         if !route.is_default().map_err(Error::InvalidData)? {
@@ -292,7 +304,7 @@ impl RouteManagerImpl {
                 let tun_gateway_link_addr =
                     tunnel_route.gateway().and_then(|addr| addr.as_link_addr());
 
-                if new_gateway_link_addr == tun_gateway_link_addr && !is_deletion {
+                if new_gateway_link_addr == tun_gateway_link_addr && !route_is_being_deleted {
                     return Ok(());
                 }
             }