freebsd-dev/sys/kern/tty_tty.c
Jordan K. Hubbard 1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00

200 lines
5.2 KiB
C

/*-
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)tty_tty.c 8.2 (Berkeley) 9/23/93
* $FreeBSD$
*/
/*
* Indirect driver for controlling tty.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/kernel.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif /*DEVFS*/
static d_open_t cttyopen;
static d_read_t cttyread;
static d_write_t cttywrite;
static d_ioctl_t cttyioctl;
static d_select_t cttyselect;
#define CDEV_MAJOR 1
/* Don't make static, fdesc_vnops uses this. */
struct cdevsw ctty_cdevsw =
{ cttyopen, nullclose, cttyread, cttywrite, /*1*/
cttyioctl, nullstop, nullreset, nodevtotty,/* tty */
cttyselect, nommap, NULL, "ctty", NULL, -1 };
#define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
/*ARGSUSED*/
static int
cttyopen(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
struct vnode *ttyvp = cttyvp(p);
int error;
if (ttyvp == NULL)
return (ENXIO);
VOP_LOCK(ttyvp);
#ifdef PARANOID
/*
* Since group is tty and mode is 620 on most terminal lines
* and since sessions protect terminals from processes outside
* your session, this check is probably no longer necessary.
* Since it inhibits setuid root programs that later switch
* to another user from accessing /dev/tty, we have decided
* to delete this test. (mckusick 5/93)
*/
error = VOP_ACCESS(ttyvp,
(flag&FREAD ? VREAD : 0) | (flag&FWRITE ? VWRITE : 0), p->p_ucred, p);
if (!error)
#endif /* PARANOID */
error = VOP_OPEN(ttyvp, flag, NOCRED, p);
VOP_UNLOCK(ttyvp);
return (error);
}
/*ARGSUSED*/
static int
cttyread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
register struct vnode *ttyvp = cttyvp(uio->uio_procp);
int error;
if (ttyvp == NULL)
return (EIO);
VOP_LOCK(ttyvp);
error = VOP_READ(ttyvp, uio, flag, NOCRED);
VOP_UNLOCK(ttyvp);
return (error);
}
/*ARGSUSED*/
static int
cttywrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
register struct vnode *ttyvp = cttyvp(uio->uio_procp);
int error;
if (ttyvp == NULL)
return (EIO);
VOP_LOCK(ttyvp);
error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
VOP_UNLOCK(ttyvp);
return (error);
}
/*ARGSUSED*/
static int
cttyioctl(dev, cmd, addr, flag, p)
dev_t dev;
int cmd;
caddr_t addr;
int flag;
struct proc *p;
{
struct vnode *ttyvp = cttyvp(p);
if (ttyvp == NULL)
return (EIO);
if (cmd == TIOCSCTTY) /* don't allow controlling tty to be set */
return EINVAL; /* to controlling tty -- infinite recursion */
if (cmd == TIOCNOTTY) {
if (!SESS_LEADER(p)) {
p->p_flag &= ~P_CONTROLT;
return (0);
} else
return (EINVAL);
}
return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, p));
}
/*ARGSUSED*/
static int
cttyselect(dev, flag, p)
dev_t dev;
int flag;
struct proc *p;
{
struct vnode *ttyvp = cttyvp(p);
if (ttyvp == NULL)
return (1); /* try operation to get EOF/failure */
return (VOP_SELECT(ttyvp, flag, FREAD|FWRITE, NOCRED, p));
}
static ctty_devsw_installed = 0;
#ifdef DEVFS
static void *ctty_devfs_token;
#endif
static void
ctty_drvinit(void *unused)
{
dev_t dev;
if( ! ctty_devsw_installed ) {
dev = makedev(CDEV_MAJOR,0);
cdevsw_add(&dev,&ctty_cdevsw,NULL);
ctty_devsw_installed = 1;
#ifdef DEVFS
ctty_devfs_token =
devfs_add_devswf(&ctty_cdevsw, 0, DV_CHR, 0, 0,
0666, "tty");
#endif
}
}
SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)