glibc/login/login_tty.c
Ulrich Drepper 174420d2bc * login/login_tty.c (login_tty): The Linux kernel can return EBUSY
for dup2 in case another thread races with the current one.  Retry
	in this case.
2007-10-04 21:54:22 +00:00

78 lines
2.5 KiB
C

/*-
* Copyright (c) 1990, 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.
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)login_tty.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <errno.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <utmp.h>
int
login_tty(fd)
int fd;
{
(void) setsid();
#ifdef TIOCSCTTY
if (ioctl(fd, TIOCSCTTY, (char *)NULL) == -1)
return (-1);
#else
{
/* This might work. */
char *fdname = ttyname (fd);
int newfd;
if (fdname)
{
if (fd != 0)
(void) close (0);
if (fd != 1)
(void) close (1);
if (fd != 2)
(void) close (2);
newfd = open (fdname, O_RDWR);
(void) close (newfd);
}
}
#endif
while (dup2(fd, 0) == -1 && errno == EBUSY)
;
while (dup2(fd, 1) == -1 && errno == EBUSY)
;
while (dup2(fd, 2) == -1 && errno == EBUSY)
;
if (fd > 2)
(void) close(fd);
return (0);
}
libutil_hidden_def (login_tty)