1/* Copyright (C) 1998-2020 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <errno.h>
20#include <fcntl.h>
21#include <stdlib.h>
22#include <unistd.h>
23#include <paths.h>
24#include <sys/statfs.h>
25
26#include "linux_fsinfo.h"
27
28/* Path to the master pseudo terminal cloning device. */
29#define _PATH_DEVPTMX _PATH_DEV "ptmx"
30/* Directory containing the UNIX98 pseudo terminals. */
31#define _PATH_DEVPTS _PATH_DEV "pts"
32
33/* Prototype for function that opens BSD-style master pseudo-terminals. */
34extern int __bsd_getpt (void) attribute_hidden;
35
36/* Open a master pseudo terminal and return its file descriptor. */
37int
38__posix_openpt (int oflag)
39{
40 static int have_no_dev_ptmx;
41 int fd;
42
43 if (!have_no_dev_ptmx)
44 {
45 fd = __open (_PATH_DEVPTMX, oflag);
46 if (fd != -1)
47 {
48 struct statfs fsbuf;
49 static int devpts_mounted;
50
51 /* Check that the /dev/pts filesystem is mounted
52 or if /dev is a devfs filesystem (this implies /dev/pts). */
53 if (devpts_mounted
54 || (__statfs (_PATH_DEVPTS, &fsbuf) == 0
55 && fsbuf.f_type == DEVPTS_SUPER_MAGIC)
56 || (__statfs (_PATH_DEV, &fsbuf) == 0
57 && fsbuf.f_type == DEVFS_SUPER_MAGIC))
58 {
59 /* Everything is ok. */
60 devpts_mounted = 1;
61 return fd;
62 }
63
64 /* If /dev/pts is not mounted then the UNIX98 pseudo terminals
65 are not usable. */
66 __close (fd);
67 have_no_dev_ptmx = 1;
68 __set_errno (ENOENT);
69 }
70 else
71 {
72 if (errno == ENOENT || errno == ENODEV)
73 have_no_dev_ptmx = 1;
74 else
75 return -1;
76 }
77 }
78 else
79 __set_errno (ENOENT);
80
81 return -1;
82}
83weak_alias (__posix_openpt, posix_openpt)
84
85
86int
87__getpt (void)
88{
89 int fd = __posix_openpt (O_RDWR);
90 if (fd == -1)
91 fd = __bsd_getpt ();
92 return fd;
93}
94
95
96#define PTYNAME1 "pqrstuvwxyzabcde";
97#define PTYNAME2 "0123456789abcdef";
98
99#define __getpt __bsd_getpt
100#define HAVE_POSIX_OPENPT
101#include <sysdeps/unix/bsd/getpt.c>
102