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/* $OpenBSD: cons.c,v 1.20 2010/06/26 23:24:44 guenther Exp $ */
/* $NetBSD: cons.c,v 1.30 1996/04/08 19:57:30 jonathan Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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. 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.
*
* from: Utah $Hdr: cons.c 1.7 92/01/21$
*
* @(#)cons.c 8.2 (Berkeley) 1/12/94
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/poll.h>
#include <dev/cons.h>
struct tty *constty = NULL; /* virtual console output device */
struct vnode *cn_devvp; /* vnode for underlying device. */
extern struct consdev *cn_tab; /* physical console device info */
int
cnopen(dev_t dev, int flag, int mode, struct proc *p)
{
dev_t cndev;
if (cn_tab == NULL)
return (0);
/*
* always open the 'real' console device, so we don't get nailed
* later. This follows normal device semantics; they always get
* open() calls.
*/
cndev = cn_tab->cn_dev;
if (cndev == NODEV)
return (ENXIO);
#ifdef DIAGNOSTIC
if (cndev == dev)
panic("cnopen: recursive");
#endif
if (cn_devvp == NULLVP) {
/* try to get a reference on its vnode, but fail silently */
cdevvp(cndev, &cn_devvp);
}
return ((*cdevsw[major(cndev)].d_open)(cndev, flag, mode, p));
}
int
cnclose(dev_t dev, int flag, int mode, struct proc *p)
{
struct vnode *vp;
if (cn_tab == NULL)
return (0);
/*
* If the real console isn't otherwise open, close it.
* If it's otherwise open, don't close it, because that'll
* screw up others who have it open.
*/
dev = cn_tab->cn_dev;
if (cn_devvp != NULLVP) {
/* release our reference to real dev's vnode */
vrele(cn_devvp);
cn_devvp = NULLVP;
}
if (vfinddev(dev, VCHR, &vp) && vcount(vp))
return (0);
return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p));
}
int
cnread(dev_t dev, struct uio *uio, int flag)
{
/*
* If we would redirect input, punt. This will keep strange
* things from happening to people who are using the real
* console. Nothing should be using /dev/console for
* input (except a shell in single-user mode, but then,
* one wouldn't TIOCCONS then).
*/
if (constty != NULL)
return 0;
else if (cn_tab == NULL)
return ENXIO;
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_read)(dev, uio, flag));
}
int
cnwrite(dev_t dev, struct uio *uio, int flag)
{
/*
* Redirect output, if that's appropriate.
* If there's no real console, return ENXIO.
*/
if (constty != NULL)
dev = constty->t_dev;
else if (cn_tab == NULL)
return ENXIO;
else
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_write)(dev, uio, flag));
}
int
cnstop(struct tty *tp, int flag)
{
return (0);
}
int
cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag,
struct proc *p)
{
int error;
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS && constty != NULL) {
error = suser(p, SUSER_NOACCT);
if (error)
return (error);
constty = NULL;
return (0);
}
/*
* Redirect the ioctl, if that's appropriate.
* Note that strange things can happen, if a program does
* ioctls on /dev/console, then the console is redirected
* out from under it.
*/
if (constty != NULL)
dev = constty->t_dev;
else if (cn_tab == NULL)
return ENXIO;
else
dev = cn_tab->cn_dev;
return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p));
}
/*ARGSUSED*/
int
cnpoll(dev_t dev, int rw, struct proc *p)
{
/*
* Redirect the poll, if that's appropriate.
* I don't want to think of the possible side effects
* of console redirection here.
*/
if (constty != NULL)
dev = constty->t_dev;
else if (cn_tab == NULL)
return POLLERR;
else
dev = cn_tab->cn_dev;
return (ttpoll(cn_tab->cn_dev, rw, p));
}
int
cnkqfilter(dev_t dev, struct knote *kn)
{
/*
* Redirect output, if that's appropriate.
* If there's no real console, return 1.
*/
if (constty != NULL)
dev = constty->t_dev;
else if (cn_tab == NULL)
return (1);
else
dev = cn_tab->cn_dev;
if (cdevsw[major(dev)].d_flags & D_KQFILTER)
return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn));
return (1);
}
int
cngetc(void)
{
if (cn_tab == NULL)
return (0);
return ((*cn_tab->cn_getc)(cn_tab->cn_dev));
}
void
cnputc(int c)
{
if (cn_tab == NULL)
return;
if (c) {
(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
if (c == '\n')
(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
}
}
void
cnpollc(int on)
{
static int refcount = 0;
if (cn_tab == NULL)
return;
if (!on)
--refcount;
if (refcount == 0)
(*cn_tab->cn_pollc)(cn_tab->cn_dev, on);
if (on)
++refcount;
}
void
nullcnpollc(dev_t dev, int on)
{
}
void
cnbell(u_int pitch, u_int period, u_int volume)
{
if (cn_tab == NULL || cn_tab->cn_bell == NULL)
return;
(*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume);
}
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