package dialer import ( "net" "syscall" "github.com/Dreamacro/clash/component/iface" "golang.org/x/sys/unix" ) type controlFn = func(network, address string, c syscall.RawConn) error func bindControl(ifaceIdx int, chain controlFn) controlFn { return func(network, address string, c syscall.RawConn) (err error) { defer func() { if err == nil && chain != nil { err = chain(network, address, c) } }() ipStr, _, err := net.SplitHostPort(address) if err == nil { ip := net.ParseIP(ipStr) if ip != nil && !ip.IsGlobalUnicast() { return } } var innerErr error err = c.Control(func(fd uintptr) { switch network { case "tcp4", "udp4": innerErr = unix.SetsockoptInt(int(fd), unix.IPPROTO_IP, unix.IP_BOUND_IF, ifaceIdx) case "tcp6", "udp6": innerErr = unix.SetsockoptInt(int(fd), unix.IPPROTO_IPV6, unix.IPV6_BOUND_IF, ifaceIdx) } }) if innerErr != nil { err = innerErr } return } } func bindIfaceToDialer(ifaceName string, dialer *net.Dialer, _ string, _ net.IP) error { ifaceObj, err := iface.ResolveInterface(ifaceName) if err != nil { return err } dialer.Control = bindControl(ifaceObj.Index, dialer.Control) return nil } func bindIfaceToListenConfig(ifaceName string, lc *net.ListenConfig, _, address string) (string, error) { ifaceObj, err := iface.ResolveInterface(ifaceName) if err != nil { return "", err } lc.Control = bindControl(ifaceObj.Index, lc.Control) return address, nil }