freebsd-dev/lib/libc/stdlib/ptsname.c
Pedro F. Giffuni d915a14ef0 libc: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-25 17:12:48 +00:00

94 lines
2.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
* All rights reserved.
*
* Portions of this software were developed under sponsorship from Snow
* B.V., the Netherlands.
*
* 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>
#ifndef lint
__FBSDID("$FreeBSD$");
#endif /* not lint */
#include "namespace.h"
#include <sys/param.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <paths.h>
#include <stdlib.h>
#include "un-namespace.h"
/*
* __isptmaster(): return whether the file descriptor refers to a
* pseudo-terminal master device.
*/
static int
__isptmaster(int fildes)
{
if (_ioctl(fildes, TIOCPTMASTER) == 0)
return (0);
if (errno != EBADF)
errno = EINVAL;
return (-1);
}
/*
* In our implementation, grantpt() and unlockpt() don't actually have
* any use, because PTY's are created on the fly and already have proper
* permissions upon creation.
*
* Just make sure `fildes' actually points to a real PTY master device.
*/
__strong_reference(__isptmaster, grantpt);
__strong_reference(__isptmaster, unlockpt);
/*
* ptsname(): return the pathname of the slave pseudo-terminal device
* associated with the specified master.
*/
char *
ptsname(int fildes)
{
static char pt_slave[sizeof _PATH_DEV + SPECNAMELEN] = _PATH_DEV;
char *ret = NULL;
/* Make sure fildes points to a master device. */
if (__isptmaster(fildes) != 0)
goto done;
if (fdevname_r(fildes, pt_slave + (sizeof _PATH_DEV - 1),
sizeof pt_slave - (sizeof _PATH_DEV - 1)) != NULL)
ret = pt_slave;
done:
return (ret);
}