package dialer import ( "context" "encoding/binary" "net" "net/netip" "syscall" "unsafe" "github.com/Dreamacro/clash/component/iface" ) const ( IP_UNICAST_IF = 31 IPV6_UNICAST_IF = 31 ) func bind4(handle syscall.Handle, ifaceIdx int) error { var bytes [4]byte binary.BigEndian.PutUint32(bytes[:], uint32(ifaceIdx)) idx := *(*uint32)(unsafe.Pointer(&bytes[0])) return syscall.SetsockoptInt(handle, syscall.IPPROTO_IP, IP_UNICAST_IF, int(idx)) } func bind6(handle syscall.Handle, ifaceIdx int) error { return syscall.SetsockoptInt(handle, syscall.IPPROTO_IPV6, IPV6_UNICAST_IF, ifaceIdx) } func bindControl(ifaceIdx int) controlFn { return func(ctx context.Context, network, address string, c syscall.RawConn) (err error) { addrPort, err := netip.ParseAddrPort(address) if err == nil && !addrPort.Addr().IsGlobalUnicast() { return } var innerErr error err = c.Control(func(fd uintptr) { handle := syscall.Handle(fd) switch network { case "tcp6", "udp6": innerErr = bind6(handle, ifaceIdx) _ = bind4(handle, ifaceIdx) default: innerErr = bind4(handle, ifaceIdx) // try bind ipv6, if failed, ignore. it's a workaround for windows disable interface ipv6 _ = bind6(handle, ifaceIdx) } }) if innerErr != nil { err = innerErr } return } } func bindIfaceToDialer(ifaceName string, dialer *net.Dialer, _ string, _ netip.Addr) error { ifaceObj, err := iface.ResolveInterface(ifaceName) if err != nil { return err } addControlToDialer(dialer, bindControl(ifaceObj.Index)) return nil } func bindIfaceToListenConfig(ifaceName string, lc *net.ListenConfig, _, address string) (string, error) { ifaceObj, err := iface.ResolveInterface(ifaceName) if err != nil { return "", err } addControlToListenConfig(lc, bindControl(ifaceObj.Index)) return address, nil } func ParseNetwork(network string, addr netip.Addr) string { return network }