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Make 'minor(dev) == 1' a device that isn't affected by TIOCCONS. 

For /dev/constty so that you can grab kernel messages when logged in
on the 'console'.
This commit is contained in:
dsl 2003-10-03 13:15:52 +00:00
parent 656ff745cf
commit 23069255ce
1 changed files with 59 additions and 52 deletions
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111
sys/dev/cons.c
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@ -1,4 +1,4 @@
/* $NetBSD: cons.c,v 1.49 2003/08/07 16:30:51 agc Exp $ */
/* $NetBSD: cons.c,v 1.50 2003/10/03 13:15:52 dsl Exp $ */
/*
* Copyright (c) 1990, 1993
@ -78,7 +78,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.49 2003/08/07 16:30:51 agc Exp $");
__KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.50 2003/10/03 13:15:52 dsl Exp $");
#include <sys/param.h>
#include <sys/proc.h>
@ -101,6 +101,8 @@ dev_type_ioctl(cnioctl);
dev_type_poll(cnpoll);
dev_type_kqfilter(cnkqfilter);
static const struct cdevsw *cn_redirect(dev_t *, int, int *);
const struct cdevsw cons_cdevsw = {
cnopen, cnclose, cnread, cnwrite, cnioctl,
nostop, notty, cnpoll, nommap, cnkqfilter, D_TTY
@ -108,13 +110,18 @@ const struct cdevsw cons_cdevsw = {
struct tty *constty = NULL; /* virtual console output device */
struct consdev *cn_tab; /* physical console device info */
struct vnode *cn_devvp; /* vnode for underlying device. */
struct vnode *cn_devvp[2]; /* vnode for underlying device. */
int
cnopen(dev_t dev, int flag, int mode, struct proc *p)
{
const struct cdevsw *cdev;
dev_t cndev;
int unit;
unit = minor(dev);
if (unit > 1)
return ENODEV;
if (cn_tab == NULL)
return (0);
@ -146,9 +153,9 @@ cnopen(dev_t dev, int flag, int mode, struct proc *p)
if (cdev == NULL)
return (ENXIO);
if (cn_devvp == NULLVP) {
if (cn_devvp[unit] == NULLVP) {
/* try to get a reference on its vnode, but fail silently */
cdevvp(cndev, &cn_devvp);
cdevvp(cndev, &cn_devvp[unit]);
}
return ((*cdev->d_open)(cndev, flag, mode, p));
}
@ -158,6 +165,9 @@ cnclose(dev_t dev, int flag, int mode, struct proc *p)
{
const struct cdevsw *cdev;
struct vnode *vp;
int unit;
unit = minor(dev);
if (cn_tab == NULL)
return (0);
@ -171,10 +181,10 @@ cnclose(dev_t dev, int flag, int mode, struct proc *p)
cdev = cdevsw_lookup(dev);
if (cdev == NULL)
return (ENXIO);
if (cn_devvp != NULLVP) {
if (cn_devvp[unit] != NULLVP) {
/* release our reference to real dev's vnode */
vrele(cn_devvp);
cn_devvp = NULLVP;
vrele(cn_devvp[unit]);
cn_devvp[unit] = NULLVP;
}
if (vfinddev(dev, VCHR, &vp) && vcount(vp))
return (0);
@ -185,6 +195,7 @@ int
cnread(dev_t dev, struct uio *uio, int flag)
{
const struct cdevsw *cdev;
int error;
/*
* If we would redirect input, punt. This will keep strange
@ -193,15 +204,9 @@ cnread(dev_t dev, struct uio *uio, int flag)
* 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;
cdev = cdevsw_lookup(dev);
cdev = cn_redirect(&dev, 1, &error);
if (cdev == NULL)
return (ENXIO);
return error;
return ((*cdev->d_read)(dev, uio, flag));
}
@ -209,20 +214,13 @@ int
cnwrite(dev_t dev, struct uio *uio, int flag)
{
const struct cdevsw *cdev;
int error;
/*
* 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;
cdev = cdevsw_lookup(dev);
/* Redirect output, if that's appropriate. */
cdev = cn_redirect(&dev, 0, &error);
if (cdev == NULL)
return (ENXIO);
return error;
return ((*cdev->d_write)(dev, uio, flag));
}
@ -250,15 +248,9 @@ cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
* 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;
cdev = cdevsw_lookup(dev);
cdev = cn_redirect(&dev, 0, &error);
if (cdev == NULL)
return (ENXIO);
return error;
return ((*cdev->d_ioctl)(dev, cmd, data, flag, p));
}
@ -267,21 +259,16 @@ int
cnpoll(dev_t dev, int events, struct proc *p)
{
const struct cdevsw *cdev;
int error;
/*
* 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;
cdev = cdevsw_lookup(dev);
cdev = cn_redirect(&dev, 0, &error);
if (cdev == NULL)
return (ENXIO);
return error;
return ((*cdev->d_poll)(dev, events, p));
}
@ -290,21 +277,16 @@ int
cnkqfilter(dev_t dev, struct knote *kn)
{
const struct cdevsw *cdev;
int error;
/*
* Redirect the kqfilter, 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;
cdev = cdevsw_lookup(dev);
cdev = cn_redirect(&dev, 0, &error);
if (cdev == NULL)
return (ENXIO);
return error;
return ((*cdev->d_kqfilter)(dev, kn));
}
@ -421,3 +403,28 @@ cnhalt(void)
return;
(*cn_tab->cn_halt)(cn_tab->cn_dev);
}
static const struct cdevsw *
cn_redirect(dev_t *devp, int is_read, int *error)
{
dev_t dev = *devp;
/*
* Redirect output, if that's appropriate.
* If there's no real console, return ENXIO.
*/
*error = ENXIO;
if (constty != NULL && minor(dev) == 0 &&
(cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE ))) {
if (is_read) {
*error = 0;
return NULL;
}
dev = constty->t_dev;
} else if (cn_tab == NULL)
return NULL;
else
dev = cn_tab->cn_dev;
*devp = dev;
return cdevsw_lookup(dev);
}