Return to cons.c CVS log

Up to [local] / src / sys / dev

Replace select backends with poll backends.  selscan() and pollscan()
now call the poll backend.  With this change we implement greater
poll(2) functionality instead of emulating it via the select backend.
Adapted from NetBSD and including some changes from FreeBSD.
Tested by many, deraadt@ OK

/*	$OpenBSD: cons.c,v 1.14 2003/09/23 16:51:12 millert 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/user.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 <dev/cons.h>

struct	tty *constty = NULL;	/* virtual console output device */
struct	consdev *cn_tab;	/* physical console device info */
struct	vnode *cn_devvp;	/* vnode for underlying device. */

int
cnopen(dev, flag, mode, p)
	dev_t dev;
	int flag, 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, flag, mode, p)
	dev_t dev;
	int flag, 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, uio, flag)
	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 && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
		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, uio, flag)
	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 && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
		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(tp, flag)
	struct tty *tp;
	int flag;
{
	return (0);
}
 
int
cnioctl(dev, cmd, data, flag, p)
	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 && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
		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, rw, p)
	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 && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
		dev = constty->t_dev;
	else if (cn_tab == NULL)
		return ENXIO;
	else
		dev = cn_tab->cn_dev;
	return (ttpoll(cn_tab->cn_dev, rw, p));
}


int
cnkqfilter(dev, kn)
	dev_t dev;
	struct knote *kn;
{

	/*
	 * Redirect output, if that's appropriate.
	 * If there's no real console, return 1.
	 */
	if (constty != NULL && (cn_tab == NULL || cn_tab->cn_pri != CN_REMOTE))
		dev = constty->t_dev;
	else if (cn_tab == NULL)
		return (1);
	else
		dev = cn_tab->cn_dev;
	if (cdevsw[major(dev)].d_type & D_KQFILTER)
		return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn));
	return (1);
}

int
cngetc()
{

	if (cn_tab == NULL)
		return (0);
	return ((*cn_tab->cn_getc)(cn_tab->cn_dev));
}

void
cnputc(c)
	register 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(on)
	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, on)
	dev_t dev;
	int on;
{

}

void
cnbell(pitch, period, volume)
	u_int pitch, period, volume;
{
	if (cn_tab == NULL || cn_tab->cn_bell == NULL)
		return;

	(*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume);
}