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- /* Copyright (C) 1998, 2000, 2001, 2002 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
- <http://www.gnu.org/licenses/>. */
- #include <stdio.h>
- #include <errno.h>
- #include <paths.h>
- #include <stdlib.h>
- #include <string.h>
- #include <sys/ioctl.h>
- #include <sys/stat.h>
- #include <sys/sysmacros.h>
- #include <termios.h>
- #include <unistd.h>
- #include <bits/uClibc_uintmaxtostr.h>
- #if !defined __UNIX98PTY_ONLY__
- /* Check if DEV corresponds to a master pseudo terminal device. */
- #define MASTER_P(Dev) \
- (major ((Dev)) == 2 \
- || (major ((Dev)) == 4 && minor ((Dev)) >= 128 && minor ((Dev)) < 192) \
- || (major ((Dev)) >= 128 && major ((Dev)) < 136))
- /* Check if DEV corresponds to a slave pseudo terminal device. */
- #define SLAVE_P(Dev) \
- (major ((Dev)) == 3 \
- || (major ((Dev)) == 4 && minor ((Dev)) >= 192 && minor ((Dev)) < 256) \
- || (major ((Dev)) >= 136 && major ((Dev)) < 144))
- /* Note that major number 4 corresponds to the old BSD style pseudo
- terminal devices. As of Linux 2.1.115 these are no longer
- supported. They have been replaced by major numbers 2 (masters)
- and 3 (slaves). */
- /* The are declared in getpt.c. */
- extern const char __libc_ptyname1[] attribute_hidden;
- extern const char __libc_ptyname2[] attribute_hidden;
- #endif
- /* Directory where we can find the slave pty nodes. */
- #define _PATH_DEVPTS "/dev/pts/"
- /* Store at most BUFLEN characters of the pathname of the slave pseudo
- terminal associated with the master FD is open on in BUF.
- Return 0 on success, otherwise an error number. */
- int ptsname_r (int fd, char *buf, size_t buflen)
- {
- int save_errno = errno;
- #if !defined __UNIX98PTY_ONLY__
- struct stat st;
- #endif
- int ptyno;
- if (buf == NULL)
- {
- errno = EINVAL;
- return EINVAL;
- }
- #if !defined __UNIX98PTY_ONLY__
- if (!isatty (fd))
- {
- errno = ENOTTY;
- return ENOTTY;
- }
- #elif !defined TIOCGPTN
- # error "__UNIX98PTY_ONLY__ enabled but TIOCGPTN ioctl not supported by your kernel."
- #endif
- #ifdef TIOCGPTN
- if (ioctl (fd, TIOCGPTN, &ptyno) == 0)
- {
- /* Buffer we use to print the number in. */
- char numbuf[__BUFLEN_INT10TOSTR];
- static const char devpts[] = _PATH_DEVPTS;
- char *p;
- p = _int10tostr(&numbuf[sizeof numbuf - 1], ptyno);
- if (buflen < sizeof(devpts) + (size_t)(&numbuf[sizeof(numbuf) - 1] - p))
- {
- errno = ERANGE;
- return ERANGE;
- }
- strcpy (buf, devpts);
- strcat (buf, p);
- /* Note: Don't bother with stat on the slave name and checking the
- driver's major device number - the ioctl above succeeded so
- we know the fd was a Unix'98 master and the /dev/pts/ prefix
- is set by definition. If the name isn't really a slave PTY,
- the system is misconfigured anyway - something else will fail
- later.
- */
- errno = save_errno;
- return 0;
- }
- #endif
- #if defined __UNIX98PTY_ONLY__
- else
- {
- /* If the ioctl fails it wasn't a Unix 98 master PTY */
- errno = ENOTTY;
- return ENOTTY;
- }
- #else
- # if defined TIOCGPTN
- else if (errno == EINVAL)
- # endif
- {
- char *p;
- if (buflen < strlen (_PATH_TTY) + 3)
- {
- errno = ERANGE;
- return ERANGE;
- }
- if (fstat (fd, &st) < 0)
- return errno;
- /* Check if FD really is a master pseudo terminal. */
- if (! MASTER_P (st.st_rdev))
- {
- errno = ENOTTY;
- return ENOTTY;
- }
- ptyno = minor (st.st_rdev);
- /* This is for the old BSD pseudo terminals. As of Linux
- 2.1.115 these are no longer supported. */
- if (major (st.st_rdev) == 4)
- ptyno -= 128;
- if (ptyno / 16 >= strlen (__libc_ptyname1))
- {
- errno = ENOTTY;
- return ENOTTY;
- }
- strcpy (buf, _PATH_TTY);
- p = buf + strlen (buf);
- p[0] = __libc_ptyname1[ptyno / 16];
- p[1] = __libc_ptyname2[ptyno % 16];
- p[2] = '\0';
- }
- if (stat(buf, &st) < 0)
- return errno;
- /* Check if the name we're about to return really corresponds to a
- slave pseudo terminal. */
- if (! S_ISCHR (st.st_mode) || ! SLAVE_P (st.st_rdev))
- {
- /* This really is a configuration problem. */
- errno = ENOTTY;
- return ENOTTY;
- }
- #endif
- errno = save_errno;
- return 0;
- }
- libc_hidden_def(ptsname_r)
- /* Return the pathname of the pseudo terminal slave assoicated with
- the master FD is open on, or NULL on errors.
- The returned storage is good until the next call to this function. */
- char *
- ptsname (int fd)
- {
- static char buffer[sizeof (_PATH_DEVPTS) + 20];
- return ptsname_r (fd, buffer, sizeof (buffer)) != 0 ? NULL : buffer;
- }
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