NetBSD/sys/kern/tty_tty.c

164 lines
4.7 KiB
C

/* $NetBSD: tty_tty.c,v 1.29 2006/07/23 22:06:11 ad Exp $ */
/*-
* Copyright (c) 1982, 1986, 1991, 1993, 1995
* 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. 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
*/
/*
* Indirect driver for controlling tty.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: tty_tty.c,v 1.29 2006/07/23 22:06:11 ad Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/kauth.h>
#define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
/*ARGSUSED*/
static int
cttyopen(dev_t dev, int flag, int mode, struct lwp *l)
{
struct vnode *ttyvp = cttyvp(l->l_proc);
int error;
if (ttyvp == NULL)
return (ENXIO);
vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
#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), l->l_cred, l);
if (!error)
#endif /* PARANOID */
error = VOP_OPEN(ttyvp, flag, NOCRED, l);
VOP_UNLOCK(ttyvp, 0);
return (error);
}
/*ARGSUSED*/
static int
cttyread(dev_t dev, struct uio *uio, int flag)
{
struct vnode *ttyvp = cttyvp(curproc);
int error;
if (ttyvp == NULL)
return (EIO);
vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_READ(ttyvp, uio, flag, NOCRED);
VOP_UNLOCK(ttyvp, 0);
return (error);
}
/*ARGSUSED*/
static int
cttywrite(dev_t dev, struct uio *uio, int flag)
{
struct vnode *ttyvp = cttyvp(curproc);
struct mount *mp;
int error;
if (ttyvp == NULL)
return (EIO);
mp = NULL;
if (ttyvp->v_type != VCHR &&
(error = vn_start_write(ttyvp, &mp, V_WAIT | V_PCATCH)) != 0)
return (error);
vn_lock(ttyvp, LK_EXCLUSIVE | LK_RETRY);
error = VOP_WRITE(ttyvp, uio, flag, NOCRED);
VOP_UNLOCK(ttyvp, 0);
vn_finished_write(mp, 0);
return (error);
}
/*ARGSUSED*/
static int
cttyioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct lwp *l)
{
struct vnode *ttyvp = cttyvp(l->l_proc);
if (ttyvp == NULL)
return (EIO);
if (cmd == TIOCSCTTY) /* XXX */
return (EINVAL);
if (cmd == TIOCNOTTY) {
if (!SESS_LEADER(l->l_proc)) {
l->l_proc->p_flag &= ~P_CONTROLT;
return (0);
} else
return (EINVAL);
}
return (VOP_IOCTL(ttyvp, cmd, addr, flag, NOCRED, l));
}
/*ARGSUSED*/
static int
cttypoll(dev_t dev, int events, struct lwp *l)
{
struct vnode *ttyvp = cttyvp(l->l_proc);
if (ttyvp == NULL)
return (seltrue(dev, events, l));
return (VOP_POLL(ttyvp, events, l));
}
static int
cttykqfilter(dev_t dev, struct knote *kn)
{
/* This is called from filt_fileattach() by the attaching process. */
struct proc *p = curproc;
struct vnode *ttyvp = cttyvp(p);
if (ttyvp == NULL)
return (1);
return (VOP_KQFILTER(ttyvp, kn));
}
const struct cdevsw ctty_cdevsw = {
cttyopen, nullclose, cttyread, cttywrite, cttyioctl,
nullstop, notty, cttypoll, nommap, cttykqfilter, D_TTY
};