| /* Copyright (C) 1998-2018 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 <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 <_itoa.h> |
| |
| /* Check if DEV corresponds to a master pseudo terminal device. */ |
| #define MASTER_P(Dev) \ |
| (__gnu_dev_major ((Dev)) == 2 \ |
| || (__gnu_dev_major ((Dev)) == 4 \ |
| && __gnu_dev_minor ((Dev)) >= 128 && __gnu_dev_minor ((Dev)) < 192) \ |
| || (__gnu_dev_major ((Dev)) >= 128 && __gnu_dev_major ((Dev)) < 136)) |
| |
| /* Check if DEV corresponds to a slave pseudo terminal device. */ |
| #define SLAVE_P(Dev) \ |
| (__gnu_dev_major ((Dev)) == 3 \ |
| || (__gnu_dev_major ((Dev)) == 4 \ |
| && __gnu_dev_minor ((Dev)) >= 192 && __gnu_dev_minor ((Dev)) < 256) \ |
| || (__gnu_dev_major ((Dev)) >= 136 && __gnu_dev_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 They have been replaced by major numbers 2 (masters) |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). */ |
| |
| /* Directory where we can find the slave pty nodes. */ |
| #define _PATH_DEVPTS "/dev/pts/" |
| |
| /* The are declared in getpt.c. */ |
| extern const char __libc_ptyname1[] attribute_hidden; |
| extern const char __libc_ptyname2[] attribute_hidden; |
| |
| /* Static buffer for `ptsname'. */ |
| static char buffer[sizeof (_PATH_DEVPTS) + 20]; |
| |
| |
| /* Return the pathname of the pseudo terminal slave associated 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) |
| { |
| return __ptsname_r (fd, buffer, sizeof (buffer)) != 0 ? NULL : buffer; |
| } |
| |
| |
| int |
| __ptsname_internal (int fd, char *buf, size_t buflen, struct stat64 *stp) |
| { |
| int save_errno = errno; |
| unsigned int ptyno; |
| |
| if (!__isatty (fd)) |
| { |
| __set_errno (ENOTTY); |
| return ENOTTY; |
| } |
| |
| #ifdef TIOCGPTN |
| if (__ioctl (fd, TIOCGPTN, &ptyno) == 0) |
| { |
| /* Buffer we use to print the number in. For a maximum size for |
| `int' of 8 bytes we never need more than 20 digits. */ |
| char numbuf[21]; |
| const char *devpts = _PATH_DEVPTS; |
| const size_t devptslen = strlen (_PATH_DEVPTS); |
| char *p; |
| |
| numbuf[sizeof (numbuf) - 1] = '\0'; |
| p = _itoa_word (ptyno, &numbuf[sizeof (numbuf) - 1], 10, 0); |
| |
| if (buflen < devptslen + (&numbuf[sizeof (numbuf)] - p)) |
| { |
| __set_errno (ERANGE); |
| return ERANGE; |
| } |
| |
| memcpy (__stpcpy (buf, devpts), p, &numbuf[sizeof (numbuf)] - p); |
| } |
| else if (errno != EINVAL) |
| return errno; |
| else |
| #endif |
| { |
| char *p; |
| |
| if (buflen < strlen (_PATH_TTY) + 3) |
| { |
| __set_errno (ERANGE); |
| return ERANGE; |
| } |
| |
| if (__fxstat64 (_STAT_VER, fd, stp) < 0) |
| return errno; |
| |
| /* Check if FD really is a master pseudo terminal. */ |
| if (! MASTER_P (stp->st_rdev)) |
| { |
| __set_errno (ENOTTY); |
| return ENOTTY; |
| } |
| |
| ptyno = __gnu_dev_minor (stp->st_rdev); |
| |
| if (ptyno / 16 >= strlen (__libc_ptyname1)) |
| { |
| __set_errno (ENOTTY); |
| return ENOTTY; |
| } |
| |
| p = __stpcpy (buf, _PATH_TTY); |
| p[0] = __libc_ptyname1[ptyno / 16]; |
| p[1] = __libc_ptyname2[ptyno % 16]; |
| p[2] = '\0'; |
| } |
| |
| if (__xstat64 (_STAT_VER, buf, stp) < 0) |
| return errno; |
| |
| /* Check if the name we're about to return really corresponds to a |
| slave pseudo terminal. */ |
| if (! S_ISCHR (stp->st_mode) || ! SLAVE_P (stp->st_rdev)) |
| { |
| /* This really is a configuration problem. */ |
| __set_errno (ENOTTY); |
| return ENOTTY; |
| } |
| |
| __set_errno (save_errno); |
| return 0; |
| } |
| |
| |
| /* 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) |
| { |
| struct stat64 st; |
| return __ptsname_internal (fd, buf, buflen, &st); |
| } |
| weak_alias (__ptsname_r, ptsname_r) |