Add no-op reset method to the DNS monitor

3 files changed, 19 insertions, 1 deletions

diff --git a/talpid-core/src/dns/mod.rs b/talpid-core/src/dns/mod.rs
index ae902da09e..1a08ec265c 100644
--- a/talpid-core/src/dns/mod.rs
+++ b/talpid-core/src/dns/mod.rs
@@ -79,6 +79,14 @@ impl DnsMonitor {
         log::info!("Resetting DNS");
         self.inner.reset()
     }
+
+    /// Reset DNS settings to what they were before being set by this instance.
+    /// If the settings only affect a specific interface, this can be a no-op,
+    /// as the interface will be destroyed.
+    pub fn reset_before_interface_removal(&mut self) -> Result<(), Error> {
+        log::info!("Resetting DNS");
+        self.inner.reset_before_interface_removal()
+    }
 }
 
 trait DnsMonitorT: Sized {
@@ -93,4 +101,8 @@ trait DnsMonitorT: Sized {
     fn set(&mut self, interface: &str, servers: &[IpAddr]) -> Result<(), Self::Error>;
 
     fn reset(&mut self) -> Result<(), Self::Error>;
+
+    fn reset_before_interface_removal(&mut self) -> Result<(), Self::Error> {
+        self.reset()
+    }
 }
diff --git a/talpid-core/src/dns/windows.rs b/talpid-core/src/dns/windows.rs
index adfe3e01e9..68742b9266 100644
--- a/talpid-core/src/dns/windows.rs
+++ b/talpid-core/src/dns/windows.rs
@@ -123,6 +123,12 @@ impl super::DnsMonitorT for DnsMonitor {
         }
         Ok(())
     }
+
+    fn reset_before_interface_removal(&mut self) -> Result<(), Self::Error> {
+        // do nothing since the tunnel interface goes away
+        let _ = self.current_index.take();
+        Ok(())
+    }
 }
 
 fn run_netsh_with_timeout(netsh_input: String, timeout: Duration) -> Result<(), Error> {
diff --git a/talpid-core/src/tunnel_state_machine/connected_state.rs b/talpid-core/src/tunnel_state_machine/connected_state.rs
index 5fc02d1052..de9f43335e 100644
--- a/talpid-core/src/tunnel_state_machine/connected_state.rs
+++ b/talpid-core/src/tunnel_state_machine/connected_state.rs
@@ -141,7 +141,7 @@ impl ConnectedState {
     }
 
     fn reset_dns(shared_values: &mut SharedTunnelStateValues) {
-        if let Err(error) = shared_values.dns_monitor.reset() {
+        if let Err(error) = shared_values.dns_monitor.reset_before_interface_removal() {
             log::error!("{}", error.display_chain_with_msg("Unable to reset DNS"));
         }
     }