Fix socket rebind on default route changes when using multihop

3 files changed, 14 insertions, 61 deletions

diff --git a/talpid-wireguard/src/wireguard_go/mod.rs b/talpid-wireguard/src/wireguard_go/mod.rs
index 6699b7a6ad..df2500c7be 100644
--- a/talpid-wireguard/src/wireguard_go/mod.rs
+++ b/talpid-wireguard/src/wireguard_go/mod.rs
@@ -337,37 +337,14 @@ impl WgGoTunnel {
     #[cfg(target_os = "windows")]
     fn default_route_changed_callback(
         event_type: talpid_routing::EventType<'_>,
-        address_family: talpid_windows::net::AddressFamily,
+        _family: talpid_windows::net::AddressFamily,
     ) {
         use talpid_routing::EventType::*;
-
-        let iface_idx: u32 = match event_type {
-            Updated(default_route) => {
-                let iface_luid = default_route.iface;
-                match talpid_windows::net::index_from_luid(&iface_luid) {
-                    Ok(idx) => idx,
-                    Err(err) => {
-                        log::error!(
-                            "Failed to convert interface LUID to interface index: {}",
-                            err,
-                        );
-                        return;
-                    },
-                }
-            }
-            // if there is no new default route, specify 0 as the interface index
-            Removed => 0,
+        match event_type {
+            // if there is no new default route, or if the route was removed, update the bind
+            Updated(_) | Removed => wireguard_go_rs::update_bind(),
             // ignore interface updates that don't affect the interface to use
-            UpdatedDetails(_) => return,
-        };
-
-        match address_family {
-            talpid_windows::net::AddressFamily::Ipv4 => {
-                wireguard_go_rs::rebind_tunnel_socket_v4(iface_idx);
-            }
-            talpid_windows::net::AddressFamily::Ipv6 => {
-                wireguard_go_rs::rebind_tunnel_socket_v6(iface_idx);
-            }
+            UpdatedDetails(_) => (),
         }
     }
 
diff --git a/wireguard-go-rs/libwg/libwg_windows.go b/wireguard-go-rs/libwg/libwg_windows.go
index fc3d9d18a2..f384b66097 100644
--- a/wireguard-go-rs/libwg/libwg_windows.go
+++ b/wireguard-go-rs/libwg/libwg_windows.go
@@ -118,24 +118,9 @@ func wgTurnOn(cIfaceName *C.char, cIfaceNameOut *C.char, cIfaceNameOutSize C.siz
 	return C.int32_t(handle)
 }
 
-//export wgRebindTunnelSocket
-func wgRebindTunnelSocket(family uint16, interfaceIndex uint32) {
+//export wgUpdateBind
+func wgUpdateBind() {
 	tunnels.ForEach(func(tunnel tunnelcontainer.Context) {
-		blackhole := (interfaceIndex == 0)
-		bind := tunnel.Device.Bind().(conn.BindSocketToInterface)
-
-		if family == windows.AF_INET {
-			tunnel.Logger.Verbosef("Binding v4 socket to interface %d (blackhole=%v)\n", interfaceIndex, blackhole)
-			err := bind.BindSocketToInterface4(interfaceIndex, blackhole)
-			if err != nil {
-				tunnel.Logger.Verbosef("%s\n", err)
-			}
-		} else if family == windows.AF_INET6 {
-			tunnel.Logger.Verbosef("Binding v6 socket to interface %d (blackhole=%v)\n", interfaceIndex, blackhole)
-			err := bind.BindSocketToInterface6(interfaceIndex, blackhole)
-			if err != nil {
-				tunnel.Logger.Verbosef("%s\n", err)
-			}
-		}
+		tunnel.Device.BindUpdate()
 	})
 }
diff --git a/wireguard-go-rs/src/lib.rs b/wireguard-go-rs/src/lib.rs
index d2f398536a..722e05c613 100644
--- a/wireguard-go-rs/src/lib.rs
+++ b/wireguard-go-rs/src/lib.rs
@@ -304,20 +304,11 @@ impl Drop for Tunnel {
     }
 }
 
-/// Rebind WireGuard IPv4 endpoint sockets to use the given interface
+/// Rebind WireGuard endpoint sockets. When the default interface changes, this needs to be called
+/// so that the UDP socket can be rebound to use the new interface
 #[cfg(target_os = "windows")]
-pub fn rebind_tunnel_socket_v4(interface_index: u32) {
-    use windows_sys::Win32::Networking::WinSock::AF_INET;
-    // SAFETY: Passing an invalid interface is safe
-    unsafe { ffi::wgRebindTunnelSocket(AF_INET, interface_index) }
-}
-
-/// Rebind WireGuard IPv6 endpoint sockets to use the given interface
-#[cfg(target_os = "windows")]
-pub fn rebind_tunnel_socket_v6(interface_index: u32) {
-    use windows_sys::Win32::Networking::WinSock::AF_INET6;
-    // SAFETY: Passing an invalid interface is safe
-    unsafe { ffi::wgRebindTunnelSocket(AF_INET6, interface_index) }
+pub fn update_bind() {
+    unsafe { ffi::wgUpdateBind() }
 }
 
 fn result_from_code(code: i32) -> Result<(), Error> {
@@ -451,8 +442,8 @@ mod ffi {
         #[cfg(target_os = "android")]
         pub fn wgGetSocketV6(handle: i32) -> Fd;
 
-        /// Rebind tunnel socket endpoint sockets
+        /// Rebind endpoint sockets
         #[cfg(target_os = "windows")]
-        pub fn wgRebindTunnelSocket(family: u16, index: u32);
+        pub fn wgUpdateBind();
     }
 }