1 /* Copyright (C) 1998, 1999 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
13
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 see <http://www.gnu.org/licenses/>. */
17
18 #include <limits.h>
19 #include <stdlib.h>
20
21 /* If __ASSUME_DEVPTS__ is defined, grantpt() reduces to a stub since we
22 assume that the devfs/devpts filesystem automatically manages the
23 permissions. */
24 #if !defined __ASSUME_DEVPTS__
25 #include <sys/statfs.h>
26
27 /* Constant that identifies the `devpts' filesystem. */
28 #define DEVPTS_SUPER_MAGIC 0x1cd1
29 /* Constant that identifies the `devfs' filesystem. */
30 #define DEVFS_SUPER_MAGIC 0x1373
31
32 /* Prototype for function that changes ownership and access permission
33 for slave pseudo terminals that do not live on a `devpts'
34 filesystem. */
35 static int __unix_grantpt (int fd);
36
37 /* Prototype for private function that gets the name of the slave
38 pseudo terminal in a safe way. */
39 static int pts_name (int fd, char **pts, size_t buf_len);
40 extern __typeof(statfs) __libc_statfs;
41
42 /* Change the ownership and access permission of the slave pseudo
43 terminal associated with the master pseudo terminal specified
44 by FD. */
grantpt(int fd)45 int grantpt (int fd)
46 {
47 struct statfs fsbuf;
48 char _buf[PATH_MAX];
49 char *buf = _buf;
50
51 if (pts_name (fd, &buf, sizeof (_buf)))
52 return -1;
53
54 if (__libc_statfs (buf, &fsbuf) < 0)
55 return -1;
56
57 /* If the slave pseudo terminal lives on a `devpts' filesystem, the
58 ownership and access permission are already set. */
59 if (fsbuf.f_type != DEVPTS_SUPER_MAGIC && fsbuf.f_type != DEVFS_SUPER_MAGIC)
60 return __unix_grantpt (fd);
61
62 return 0;
63 }
64
65 # define grantpt __unix_grantpt
66 # include "unix_grantpt.c"
67
68 #else
69
grantpt(attribute_unused int fd)70 int grantpt (attribute_unused int fd)
71 {
72 return 0;
73 }
74
75 #endif
76