ssize_t vnc_client_read_buf(VncState *vs, uint8_t *data, size_t datalen);
ssize_t vnc_client_write_buf(VncState *vs, const uint8_t *data, size_t datalen);
ssize_t vnc_client_read_buf(VncState *vs, uint8_t *data, size_t datalen);
ssize_t vnc_client_write_buf(VncState *vs, const uint8_t *data, size_t datalen);