const struct telnet_special *(*get_specials) (void *handle);
Socket(*socket) (void *handle);
int (*exitcode) (void *handle);
+ /* If back->sendok() returns FALSE, data sent to it from the frontend
+ * may be lost. */
int (*sendok) (void *handle);
int (*ldisc) (void *handle, int);
void (*provide_ldisc) (void *handle, void *ldisc);