package internet import ( "encoding/binary" "net" "syscall" "unsafe" "github.com/xtls/xray-core/common/errors" ) const ( TCP_FASTOPEN = 15 IP_UNICAST_IF = 31 IPV6_UNICAST_IF = 31 ) func setTFO(fd syscall.Handle, tfo int) error { if tfo > 0 { tfo = 1 } if tfo >= 0 { if err := syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, TCP_FASTOPEN, tfo); err != nil { return err } } return nil } func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error { if config.Interface != "" { inf, err := net.InterfaceByName(config.Interface) if err != nil { return errors.New("failed to find the interface").Base(err) } isV4 := (network == "tcp4") if isV4 { var bytes [4]byte binary.BigEndian.PutUint32(bytes[:], uint32(inf.Index)) idx := *(*uint32)(unsafe.Pointer(&bytes[0])) if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IP, IP_UNICAST_IF, int(idx)); err != nil { return errors.New("failed to set IP_UNICAST_IF").Base(err) } } else { if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IPV6, IPV6_UNICAST_IF, inf.Index); err != nil { return errors.New("failed to set IPV6_UNICAST_IF").Base(err) } } } if isTCPSocket(network) { if err := setTFO(syscall.Handle(fd), config.ParseTFOValue()); err != nil { return err } if config.TcpKeepAliveIdle > 0 { if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil { return errors.New("failed to set SO_KEEPALIVE", err) } } else if config.TcpKeepAliveIdle < 0 { if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 0); err != nil { return errors.New("failed to unset SO_KEEPALIVE", err) } } if config.TcpNoDelay { if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_TCP, syscall.TCP_NODELAY, 1); err != nil { return errors.New("failed to set TCP_NODELAY", err) } } } return nil } func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig) error { if isTCPSocket(network) { if err := setTFO(syscall.Handle(fd), config.ParseTFOValue()); err != nil { return err } if config.TcpKeepAliveIdle > 0 { if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 1); err != nil { return errors.New("failed to set SO_KEEPALIVE", err) } } else if config.TcpKeepAliveIdle < 0 { if err := syscall.SetsockoptInt(syscall.Handle(fd), syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, 0); err != nil { return errors.New("failed to unset SO_KEEPALIVE", err) } } } return nil } func bindAddr(fd uintptr, ip []byte, port uint32) error { return nil } func setReuseAddr(fd uintptr) error { return nil } func setReusePort(fd uintptr) error { return nil }