freebsd-nq/sys/kern/tty_conf.c
Peter Dufault 3749fcff67 Set it so you can add and remove line disciplines without replicating
code for looking for open slots in table (and you could hide the table
if you wanted to).
1995-03-21 11:24:05 +00:00

172 lines
5.0 KiB
C

/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)tty_conf.c 8.4 (Berkeley) 1/21/94
* $Id: tty_conf.c,v 1.4 1994/10/05 21:22:24 wollman Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/conf.h>
#define ttynodisc ((int (*) __P((dev_t, struct tty *)))enodev)
#define ttyerrclose ((int (*) __P((struct tty *, int flags)))enodev)
#define ttyerrio ((int (*) __P((struct tty *, struct uio *, int)))enodev)
#define ttyerrinput ((int (*) __P((int c, struct tty *)))enodev)
#define ttyerrstart ((int (*) __P((struct tty *)))enodev)
int nullioctl __P((struct tty *tp, int cmd, caddr_t data,
int flag, struct proc *p));
#ifndef MAXLDISC
#define MAXLDISC 8
#endif
#define NODISC(n) \
{ ttynodisc, ttyerrclose, ttyerrio, ttyerrio, nullioctl, \
ttyerrinput, ttyerrstart, nullmodem },
struct linesw linesw[MAXLDISC] =
{
{ ttyopen, ttylclose, ttread, ttwrite, nullioctl,
ttyinput, ttstart, ttymodem }, /* 0- termios */
{ ttynodisc, ttyerrclose, ttyerrio, ttyerrio, nullioctl,
ttyerrinput, ttyerrstart, nullmodem }, /* 1- defunct */
#ifdef COMPAT_43
{ ttyopen, ttylclose, ttread, ttwrite, nullioctl,
ttyinput, ttstart, ttymodem }, /* 2- NTTYDISC */
#else
{ ttynodisc, ttyerrclose, ttyerrio, ttyerrio, nullioctl,
ttyerrinput, ttyerrstart, nullmodem },
#endif
NODISC(3) /* TABLDISC */
NODISC(4) /* SLIPDISC */
NODISC(5) /* PPPDISC */
NODISC(6) /* loadable */
NODISC(7) /* loadable */
};
int nlinesw = sizeof (linesw) / sizeof (linesw[0]);
static struct linesw nodisc =
{
ttynodisc,
ttyerrclose,
ttyerrio,
ttyerrio,
nullioctl,
ttyerrinput,
ttyerrstart,
nullmodem
};
#define LOADABLE_LDISC 6
/*
* ldisc_register: Register a line discipline.
*
* discipline: Index for discipline to load, or LDISC_LOAD for us to choose.
* linesw_p: Pointer to linesw_p.
*
* Returns: Index used or -1 on failure.
*/
int
ldisc_register(discipline, linesw_p)
int discipline;
struct linesw *linesw_p;
{
int slot = -1;
if (discipline == LDISC_LOAD) {
int i;
for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
if (bcmp(linesw + i, &nodisc, sizeof(nodisc)) == 0) {
slot = i;
}
}
else if (discipline >= 0 && discipline < MAXLDISC) {
slot = discipline;
}
if (slot != -1 && linesw_p)
linesw[slot] = *linesw_p;
return slot;
}
/*
* ldisc_deregister: Deregister a line discipline obtained with
* ldisc_register. Can only deregister "loadable" ones now.
*
* discipline: Index for discipline to unload.
*/
void
ldisc_deregister(discipline)
int discipline;
{
if (discipline >= LOADABLE_LDISC && discipline < MAXLDISC) {
linesw[discipline] = nodisc;
}
}
/*
* Do nothing specific version of line
* discipline specific ioctl command.
*/
/*ARGSUSED*/
int
nullioctl(tp, cmd, data, flags, p)
struct tty *tp;
int cmd;
char *data;
int flags;
struct proc *p;
{
#ifdef lint
tp = tp; data = data; flags = flags; p = p;
#endif
return (-1);
}