freebsd-dev/sys/kern/tty_cons.c
2000-07-04 11:25:35 +00:00

457 lines
10 KiB
C

/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1991 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. 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.
*
* from: @(#)cons.c 7.2 (Berkeley) 5/9/91
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/uio.h>
#include <machine/cpu.h>
static d_open_t cnopen;
static d_close_t cnclose;
static d_read_t cnread;
static d_write_t cnwrite;
static d_ioctl_t cnioctl;
static d_poll_t cnpoll;
#define CDEV_MAJOR 0
static struct cdevsw cn_cdevsw = {
/* open */ cnopen,
/* close */ cnclose,
/* read */ cnread,
/* write */ cnwrite,
/* ioctl */ cnioctl,
/* poll */ cnpoll,
/* mmap */ nommap,
/* strategy */ nostrategy,
/* name */ "console",
/* maj */ CDEV_MAJOR,
/* dump */ nodump,
/* psize */ nopsize,
/* flags */ D_TTY,
/* bmaj */ -1
};
static dev_t cn_dev_t; /* seems to be never really used */
static udev_t cn_udev_t;
SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD,
&cn_udev_t, sizeof cn_udev_t, "T,dev_t", "");
static int cn_mute;
int cons_unavail = 0; /* XXX:
* physical console not available for
* input (i.e., it is in graphics mode)
*/
static u_char cn_is_open; /* nonzero if logical console is open */
static int openmode, openflag; /* how /dev/console was openned */
static dev_t cn_devfsdev; /* represents the device private info */
static u_char cn_phys_is_open; /* nonzero if physical device is open */
static d_close_t *cn_phys_close; /* physical device close function */
static d_open_t *cn_phys_open; /* physical device open function */
struct consdev *cn_tab; /* physical console device info */
CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
void
cninit()
{
struct consdev *best_cp, *cp, **list;
/*
* Find the first console with the highest priority.
*/
best_cp = NULL;
list = (struct consdev **)cons_set.ls_items;
while ((cp = *list++) != NULL) {
if (cp->cn_probe == NULL)
continue;
(*cp->cn_probe)(cp);
if (cp->cn_pri > CN_DEAD &&
(best_cp == NULL || cp->cn_pri > best_cp->cn_pri))
best_cp = cp;
}
/*
* Check if we should mute the console (for security reasons perhaps)
* It can be changes dynamically using sysctl kern.consmute
* once we are up and going.
*
*/
cn_mute = ((boothowto & (RB_MUTE
|RB_SINGLE
|RB_VERBOSE
|RB_ASKNAME
|RB_CONFIG)) == RB_MUTE);
/*
* If no console, give up.
*/
if (best_cp == NULL) {
if (cn_tab != NULL && cn_tab->cn_term != NULL)
(*cn_tab->cn_term)(cn_tab);
cn_tab = best_cp;
return;
}
/*
* Initialize console, then attach to it. This ordering allows
* debugging using the previous console, if any.
*/
(*best_cp->cn_init)(best_cp);
if (cn_tab != NULL && cn_tab != best_cp) {
/* Turn off the previous console. */
if (cn_tab->cn_term != NULL)
(*cn_tab->cn_term)(cn_tab);
}
cn_tab = best_cp;
}
void
cninit_finish()
{
struct cdevsw *cdp;
if ((cn_tab == NULL) || cn_mute)
return;
/*
* Hook the open and close functions.
*/
cdp = devsw(cn_tab->cn_dev);
if (cdp != NULL) {
cn_phys_close = cdp->d_close;
cdp->d_close = cnclose;
cn_phys_open = cdp->d_open;
cdp->d_open = cnopen;
}
cn_dev_t = cn_tab->cn_dev;
cn_udev_t = dev2udev(cn_dev_t);
}
static void
cnuninit(void)
{
struct cdevsw *cdp;
if (cn_tab == NULL)
return;
/*
* Unhook the open and close functions.
*/
cdp = devsw(cn_tab->cn_dev);
if (cdp != NULL) {
cdp->d_close = cn_phys_close;
cdp->d_open = cn_phys_open;
}
cn_phys_close = NULL;
cn_phys_open = NULL;
cn_dev_t = NODEV;
cn_udev_t = NOUDEV;
}
/*
* User has changed the state of the console muting.
* This may require us to open or close the device in question.
*/
static int
sysctl_kern_consmute(SYSCTL_HANDLER_ARGS)
{
int error;
int ocn_mute;
ocn_mute = cn_mute;
error = sysctl_handle_int(oidp, &cn_mute, 0, req);
if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) {
if(ocn_mute && !cn_mute) {
/*
* going from muted to unmuted.. open the physical dev
* if the console has been openned
*/
cninit_finish();
if(cn_is_open)
/* XXX curproc is not what we want really */
error = cnopen(cn_dev_t, openflag,
openmode, curproc);
/* if it failed, back it out */
if ( error != 0) cnuninit();
} else if (!ocn_mute && cn_mute) {
/*
* going from unmuted to muted.. close the physical dev
* if it's only open via /dev/console
*/
if(cn_is_open)
error = cnclose(cn_dev_t, openflag,
openmode, curproc);
if ( error == 0) cnuninit();
}
if (error != 0) {
/*
* back out the change if there was an error
*/
cn_mute = ocn_mute;
}
}
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW,
0, sizeof cn_mute, sysctl_kern_consmute, "I", "");
static int
cnopen(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
dev_t cndev, physdev;
int retval = 0;
if (cn_tab == NULL || cn_phys_open == NULL)
return (0);
cndev = cn_tab->cn_dev;
physdev = (major(dev) == major(cndev) ? dev : cndev);
/*
* If mute is active, then non console opens don't get here
* so we don't need to check for that. They
* bypass this and go straight to the device.
*/
if(!cn_mute)
retval = (*cn_phys_open)(physdev, flag, mode, p);
if (retval == 0) {
/*
* check if we openned it via /dev/console or
* via the physical entry (e.g. /dev/sio0).
*/
if (dev == cndev)
cn_phys_is_open = 1;
else if (physdev == cndev) {
openmode = mode;
openflag = flag;
cn_is_open = 1;
}
dev->si_tty = physdev->si_tty;
}
return (retval);
}
static int
cnclose(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
dev_t cndev;
struct tty *cn_tp;
if (cn_tab == NULL || cn_phys_open == NULL)
return (0);
cndev = cn_tab->cn_dev;
cn_tp = cndev->si_tty;
/*
* act appropriatly depending on whether it's /dev/console
* or the pysical device (e.g. /dev/sio) that's being closed.
* in either case, don't actually close the device unless
* both are closed.
*/
if (dev == cndev) {
/* the physical device is about to be closed */
cn_phys_is_open = 0;
if (cn_is_open) {
if (cn_tp) {
/* perform a ttyhalfclose() */
/* reset session and proc group */
cn_tp->t_pgrp = NULL;
cn_tp->t_session = NULL;
}
return (0);
}
} else if (major(dev) != major(cndev)) {
/* the logical console is about to be closed */
cn_is_open = 0;
if (cn_phys_is_open)
return (0);
dev = cndev;
}
if(cn_phys_close)
return ((*cn_phys_close)(dev, flag, mode, p));
return (0);
}
static int
cnread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
if (cn_tab == NULL || cn_phys_open == NULL)
return (0);
dev = cn_tab->cn_dev;
return ((*devsw(dev)->d_read)(dev, uio, flag));
}
static int
cnwrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
if (cn_tab == NULL || cn_phys_open == NULL) {
uio->uio_resid = 0; /* dump the data */
return (0);
}
if (constty)
dev = constty->t_dev;
else
dev = cn_tab->cn_dev;
return ((*devsw(dev)->d_write)(dev, uio, flag));
}
static int
cnioctl(dev, cmd, data, flag, p)
dev_t dev;
u_long cmd;
caddr_t data;
int flag;
struct proc *p;
{
int error;
if (cn_tab == NULL || cn_phys_open == NULL)
return (0);
/*
* Superuser can always use this to wrest control of console
* output from the "virtual" console.
*/
if (cmd == TIOCCONS && constty) {
error = suser(p);
if (error)
return (error);
constty = NULL;
return (0);
}
dev = cn_tab->cn_dev;
return ((*devsw(dev)->d_ioctl)(dev, cmd, data, flag, p));
}
static int
cnpoll(dev, events, p)
dev_t dev;
int events;
struct proc *p;
{
if ((cn_tab == NULL) || cn_mute)
return (1);
dev = cn_tab->cn_dev;
return ((*devsw(dev)->d_poll)(dev, events, p));
}
int
cngetc()
{
int c;
if ((cn_tab == NULL) || cn_mute)
return (-1);
c = (*cn_tab->cn_getc)(cn_tab->cn_dev);
if (c == '\r') c = '\n'; /* console input is always ICRNL */
return (c);
}
int
cncheckc()
{
if ((cn_tab == NULL) || cn_mute)
return (-1);
return ((*cn_tab->cn_checkc)(cn_tab->cn_dev));
}
void
cnputc(c)
register int c;
{
if ((cn_tab == NULL) || cn_mute)
return;
if (c) {
if (c == '\n')
(*cn_tab->cn_putc)(cn_tab->cn_dev, '\r');
(*cn_tab->cn_putc)(cn_tab->cn_dev, c);
}
}
void
cndbctl(on)
int on;
{
static int refcount;
if (cn_tab == NULL)
return;
if (!on)
refcount--;
if (refcount == 0 && cn_tab->cn_dbctl != NULL)
(*cn_tab->cn_dbctl)(cn_tab->cn_dev, on);
if (on)
refcount++;
}
static void
cn_drvinit(void *unused)
{
cn_devfsdev = make_dev(&cn_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
"console");
}
SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL)