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/*-
* Copyright (c) 2004 Poul-Henning Kamp. All rights reserved.
* 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.
* 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
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/tty.h>
#include <sys/conf.h>
#ifndef MAXLDISC
#define MAXLDISC 9
#endif
static l_open_t l_noopen;
static l_close_t l_noclose;
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.
*/
static struct linesw nodisc = {
.l_open = l_noopen,
.l_close = l_noclose,
.l_read = l_noread,
.l_write = l_nowrite,
.l_ioctl = l_nullioctl,
.l_rint = l_norint,
.l_start = l_nostart,
.l_modem = ttymodem
};
static struct linesw termios_disc = {
.l_open = tty_open,
.l_close = ttylclose,
.l_read = ttread,
.l_write = ttwrite,
.l_ioctl = l_nullioctl,
.l_rint = ttyinput,
.l_start = ttstart,
.l_modem = ttymodem
};
#ifdef COMPAT_43
# define ntty_disc termios_disc
#else
# define ntty_disc nodisc
#endif
struct linesw *linesw[MAXLDISC] = {
&termios_disc, /* 0 - termios */
&nodisc, /* 1 - defunct */
&ntty_disc, /* 2 - NTTYDISC */
&nodisc, /* 3 - loadable */
&nodisc, /* 4 - SLIPDISC */
&nodisc, /* 5 - PPPDISC */
&nodisc, /* 6 - NETGRAPHDISC */
&nodisc, /* 7 - loadable */
&nodisc, /* 8 - loadable */
};
int nlinesw = sizeof (linesw) / sizeof (linesw[0]);
#define LOADABLE_LDISC 7
/*
* 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(int discipline, struct linesw *linesw_p)
{
int slot = -1;
if (discipline == LDISC_LOAD) {
int i;
for (i = LOADABLE_LDISC; i < MAXLDISC; i++)
if (linesw[i] == &nodisc) {
slot = i;
break;
}
} 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.
*
* discipline: Index for discipline to unload.
*/
void
ldisc_deregister(int discipline)
{
if (discipline < MAXLDISC)
linesw[discipline] = &nodisc;
}
/*
* "no" and "null" versions of line discipline functions
*/
static int
l_noopen(struct cdev *dev, struct tty *tp)
{
return (ENODEV);
}
static int
l_noclose(struct tty *tp, int flag)
{
return (ENODEV);
}
int
l_noread(struct tty *tp, struct uio *uio, int flag)
{
return (ENODEV);
}
int
l_nowrite(struct tty *tp, struct uio *uio, int flag)
{
return (ENODEV);
}
static int
l_norint(int c, struct tty *tp)
{
return (ENODEV);
}
static int
l_nostart(struct tty *tp)
{
return (ENODEV);
}
int
l_nullioctl(struct tty *tp, u_long cmd, char *data, int flags, struct thread *td)
{
return (ENOIOCTL);
}
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