glibc/login/openpty.c
Paul Eggert 2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00

161 lines
3.8 KiB
C

/* Copyright (C) 1998-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pty.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
/* Return the result of ptsname_r in the buffer pointed to by PTS,
which should be of length BUF_LEN. If it is too long to fit in
this buffer, a sufficiently long buffer is allocated using malloc,
and returned in PTS. 0 is returned upon success, -1 otherwise. */
static int
pts_name (int fd, char **pts, size_t buf_len)
{
int rv;
char *buf = *pts;
for (;;)
{
char *new_buf;
if (buf_len)
{
rv = ptsname_r (fd, buf, buf_len);
if (rv != 0 || memchr (buf, '\0', buf_len))
/* We either got an error, or we succeeded and the
returned name fit in the buffer. */
break;
/* Try again with a longer buffer. */
buf_len += buf_len; /* Double it */
}
else
/* No initial buffer; start out by mallocing one. */
buf_len = 128; /* First time guess. */
if (buf != *pts)
/* We've already malloced another buffer at least once. */
new_buf = realloc (buf, buf_len);
else
new_buf = malloc (buf_len);
if (! new_buf)
{
rv = -1;
__set_errno (ENOMEM);
break;
}
buf = new_buf;
}
if (rv == 0)
*pts = buf; /* Return buffer to the user. */
else if (buf != *pts)
free (buf); /* Free what we malloced when returning an error. */
return rv;
}
/* Create pseudo tty master slave pair and set terminal attributes
according to TERMP and WINP. Return handles for both ends in
AMASTER and ASLAVE, and return the name of the slave end in NAME. */
int
openpty (int *amaster, int *aslave, char *name,
const struct termios *termp, const struct winsize *winp)
{
#ifdef PATH_MAX
char _buf[PATH_MAX];
#else
char _buf[512];
#endif
char *buf = _buf;
int master, ret = -1, slave = -1;
*buf = '\0';
master = getpt ();
if (master == -1)
return -1;
if (grantpt (master))
goto on_error;
if (unlockpt (master))
goto on_error;
#ifdef TIOCGPTPEER
/* Try to allocate slave fd solely based on master fd first. */
slave = ioctl (master, TIOCGPTPEER, O_RDWR | O_NOCTTY);
#endif
if (slave == -1)
{
/* Fallback to path-based slave fd allocation in case kernel doesn't
* support TIOCGPTPEER.
*/
if (pts_name (master, &buf, sizeof (_buf)))
goto on_error;
slave = open (buf, O_RDWR | O_NOCTTY);
if (slave == -1)
goto on_error;
}
/* XXX Should we ignore errors here? */
if (termp)
tcsetattr (slave, TCSAFLUSH, termp);
#ifdef TIOCSWINSZ
if (winp)
ioctl (slave, TIOCSWINSZ, winp);
#endif
*amaster = master;
*aslave = slave;
if (name != NULL)
{
if (*buf == '\0')
if (pts_name (master, &buf, sizeof (_buf)))
goto on_error;
strcpy (name, buf);
}
ret = 0;
on_error:
if (ret == -1) {
close (master);
if (slave != -1)
close (slave);
}
if (buf != _buf)
free (buf);
return ret;
}
libutil_hidden_def (openpty)