The
NetBSD TTY line discipline framework allows extensibility. Modules that need special line disciplines can add them as convenient and do not need to modify tty_conf.c. Line disciplines are now managed by a string, rather than number.
Once the framework has been initialized, a new line discipline can be added by creating and initializing a
struct linesw and calling
ttyldisc_add().
The following is a brief description of each function in the framework:
ttyldisc_add()
Register a line discipline. The l_name field of the struct linesw should point to a string which is to be the symbolic name of that line discipline. For compatibility purposes, a line discipline number can be passed in no, but for new disciplines this should be set to -1.
ttyldisc_lookup()
Look up a line discipline by name. NULL is returned if it can not be found.
ttyldisc_remove()
Remove a line discipline called name and return a pointer to it. If the discipline cannot be found or removed ttyldisc_remove() will return NULL.