realityone / akarin Goto Github PK

fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
        if !buf.len() > 0 {
            return Ok(0);
        };

        let mut data = Vec::with_capacity(buf.len() + IP_HEADER_LEN);
        match buf[0] >> 4 {
            IPV4 => data.extend_from_slice(&IPV4_HEADER),
            IPV6 => data.extend_from_slice(&IPV6_HEADER),
            _    => {}
        };
        // Fix
        data.extend_from_slice(&buf);

        match self.tun.write(&data) {
            Ok(len) => Ok(if len > IP_HEADER_LEN { len - IP_HEADER_LEN } else { 0 }),
            Err(e)  => Err(e),
        }
    }

    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
        match self.tun.read(buf) {
            Ok(size) => {
                if size > IP_HEADER_LEN {
                    unsafe {
                        let buf_copy: &mut [u8] = ::std::mem::transmute_copy(&buf);
                        let mut idx = IP_HEADER_LEN;
                        while idx < buf.len() {
                            buf[idx-IP_HEADER_LEN] = buf_copy[idx];
                            idx += 1;
                        }
                        ::std::mem::forget(buf_copy);
                    }
                    Ok(size-IP_HEADER_LEN)
                } else {
                    Ok(size)
                }
            },
            Err(e) => Err(e)
        }
    }