// go:build windows package tlsmiddlebox // // syscall utilities for dialerTTLWrapperConn // import ( "net" "syscall" ) // SetTTL sets the IP TTL field for the underlying net.TCPConn func (c *dialerTTLWrapperConn) SetTTL(ttl int) error { conn := c.Conn tcpConn, ok := conn.(*net.TCPConn) if !ok { return errInvalidConnWrapper } rawConn, err := tcpConn.SyscallConn() if err != nil { return err } rawErr := rawConn.Control(func(fd uintptr) { err = syscall.SetsockoptInt(syscall.Handle(fd), syscall.IPPROTO_IP, syscall.IP_TTL, ttl) }) // The syscall err is given a higher priority and returned early if non-nil if err != nil { return err } return rawErr } // GetSoErr fetches the SO_ERROR value at look for soft ICMP errors in TCP func (c *dialerTTLWrapperConn) GetSoErr() (int, error) { var cErrno int conn := c.Conn tcpConn, ok := conn.(*net.TCPConn) if !ok { return 0, errInvalidConnWrapper } rawConn, err := tcpConn.SyscallConn() if err != nil { return 0, errInvalidConnWrapper } rawErr := rawConn.Control(func(fd uintptr) { cErrno = getErrFromSockOpt(fd) }) if rawErr != nil { return 0, rawErr } return cErrno, nil }