freebsd-dev/sys/kern/tty_conf.c
1997-02-22 09:48:43 +00:00

209 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
* $Id$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <sys/conf.h>
#ifndef MAXLDISC
#define MAXLDISC 8
#endif
static l_open_t l_noopen;
static l_close_t l_noclose;
static l_ioctl_t l_nullioctl;
static l_rint_t l_norint;
static l_start_t l_nostart;
/*
* XXX it probably doesn't matter what the entries other than the l_open
* entry are here. The l_nullioctl and ttymodem entries still look fishy.
* Reconsider the removal of nullmodem anyway. It was too much like
* ttymodem, but a completely null version might be useful.
*/
#define NODISC(n) \
{ l_noopen, l_noclose, l_noread, l_nowrite, \
l_nullioctl, l_norint, l_nostart, ttymodem }
struct linesw linesw[MAXLDISC] =
{
/* 0- termios */
{ ttyopen, ttylclose, ttread, ttwrite,
l_nullioctl, ttyinput, ttstart, ttymodem },
NODISC(1), /* 1- defunct */
/* 2- NTTYDISC */
#ifdef COMPAT_43
{ ttyopen, ttylclose, ttread, ttwrite,
l_nullioctl, ttyinput, ttstart, ttymodem },
#else
NODISC(2),
#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 = NODISC(0);
#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;
}
}
static int
l_noopen(dev, tp)
dev_t dev;
struct tty *tp;
{
return (ENODEV);
}
static int
l_noclose(tp, flag)
struct tty *tp;
int flag;
{
return (ENODEV);
}
int
l_noread(tp, uio, flag)
struct tty *tp;
struct uio *uio;
int flag;
{
return (ENODEV);
}
int
l_nowrite(tp, uio, flag)
struct tty *tp;
struct uio *uio;
int flag;
{
return (ENODEV);
}
static int
l_norint(c, tp)
int c;
struct tty *tp;
{
return (ENODEV);
}
static int
l_nostart(tp)
struct tty *tp;
{
return (ENODEV);
}
/*
* Do nothing specific version of line
* discipline specific ioctl command.
*/
static int
l_nullioctl(tp, cmd, data, flags, p)
struct tty *tp;
int cmd;
char *data;
int flags;
struct proc *p;
{
return (-1);
}