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/*-
* 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/lock.h>
#include <sys/proc.h>
#include <sys/ttycom.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
static d_open_t cttyopen;
static d_read_t cttyread;
static d_write_t cttywrite;
static d_ioctl_t cttyioctl;
static d_poll_t cttypoll;
#define CDEV_MAJOR 1
/* Don't make this static, since fdesc_vnops uses it. */
struct cdevsw ctty_cdevsw = {
/* open */ cttyopen,
/* close */ nullclose,
/* read */ cttyread,
/* write */ cttywrite,
/* ioctl */ cttyioctl,
/* stop */ nostop,
/* reset */ noreset,
/* devtotty */ nodevtotty,
/* poll */ cttypoll,
/* mmap */ nommap,
/* strategy */ nostrategy,
/* name */ "ctty",
/* parms */ noparms,
/* maj */ CDEV_MAJOR,
/* dump */ nodump,
/* psize */ nopsize,
/* flags */ D_TTY,
/* maxio */ 0,
/* bmaj */ -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);
vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
#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, 0, p);
return (error);
}
/*ARGSUSED*/
static int
cttyread(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
struct proc *p = uio->uio_procp;
register struct vnode *ttyvp = cttyvp(p);
int error;
if (ttyvp == NULL)
return (EIO);
vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
error = VOP_READ(ttyvp, uio, flag, NOCRED);
VOP_UNLOCK(ttyvp, 0, p);
return (error);
}
/*ARGSUSED*/
static int
cttywrite(dev, uio, flag)
dev_t dev;
struct uio *uio;
int flag;
{
struct proc *p = uio->uio_procp;
struct vnode *ttyvp = cttyvp(uio->uio_procp);
int error;
if (ttyvp == NULL)
return (EIO);
vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY, p);
error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
VOP_UNLOCK(ttyvp, 0, p);
return (error);
}
/*ARGSUSED*/
static int
cttyioctl(dev, cmd, addr, flag, p)
dev_t dev;
u_long 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
cttypoll(dev, events, p)
dev_t dev;
int events;
struct proc *p;
{
struct vnode *ttyvp = cttyvp(p);
if (ttyvp == NULL)
/* try operation to get EOF/failure */
return (seltrue(dev, events, p));
return (VOP_POLL(ttyvp, events, p->p_ucred, p));
}
static void ctty_drvinit __P((void *unused));
static void
ctty_drvinit(unused)
void *unused;
{
make_dev(&ctty_cdevsw, 0, 0, 0, 0666, "tty");
}
SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,ctty_drvinit,NULL)
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