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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003 Poul-Henning Kamp. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/eventhandler.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/sx.h>
#include <sys/vnode.h>
#include <fs/devfs/devfs.h>
#include <fs/devfs/devfs_int.h>
static d_open_t cttyopen;
static struct cdevsw ctty_cdevsw = {
.d_version = D_VERSION,
.d_open = cttyopen,
.d_name = "ctty",
};
static struct cdev *ctty;
static int
cttyopen(struct cdev *dev, int flag, int mode, struct thread *td)
{
return (ENXIO);
}
static void
ctty_clone(void *arg, struct ucred *cred, char *name, int namelen,
struct cdev **dev)
{
struct proc *p;
if (*dev != NULL)
return;
if (strcmp(name, "tty"))
return;
p = curproc;
sx_sunlock(&clone_drain_lock);
sx_slock(&proctree_lock);
sx_slock(&clone_drain_lock);
dev_lock();
if (!(p->p_flag & P_CONTROLT))
*dev = ctty;
else if (p->p_session->s_ttyvp == NULL)
*dev = ctty;
else if (p->p_session->s_ttyvp->v_type == VBAD ||
p->p_session->s_ttyvp->v_rdev == NULL) {
/* e.g. s_ttyvp was revoked */
*dev = ctty;
} else
*dev = p->p_session->s_ttyvp->v_rdev;
dev_refl(*dev);
dev_unlock();
sx_sunlock(&proctree_lock);
}
static void
ctty_drvinit(void *unused)
{
EVENTHANDLER_REGISTER(dev_clone, ctty_clone, 0, 1000);
ctty = make_dev_credf(MAKEDEV_ETERNAL, &ctty_cdevsw, 0, NULL, UID_ROOT,
GID_WHEEL, 0666, "ctty");
}
SYSINIT(cttydev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,ctty_drvinit,NULL);
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