1 | /* Copyright (C) 1991-2022 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 Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the 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 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library; if not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | #include <errno.h> |
19 | #include <limits.h> |
20 | #include <stddef.h> |
21 | #include <dirent.h> |
22 | #include <sys/types.h> |
23 | #include <sys/stat.h> |
24 | #include <unistd.h> |
25 | #include <string.h> |
26 | #include <stdlib.h> |
27 | |
28 | #ifndef MIN |
29 | # define MIN(a, b) ((a) < (b) ? (a) : (b)) |
30 | #endif |
31 | |
32 | static const char dev[] = "/dev" ; |
33 | |
34 | static int getttyname_r (int fd, char *buf, size_t buflen, |
35 | dev_t mydev, ino_t myino, int save, |
36 | int *dostat) __THROW; |
37 | |
38 | static int |
39 | getttyname_r (int fd, char *buf, size_t buflen, dev_t mydev, ino_t myino, |
40 | int save, int *dostat) |
41 | { |
42 | struct stat st; |
43 | DIR *dirstream; |
44 | struct dirent *d; |
45 | |
46 | dirstream = __opendir (name: dev); |
47 | if (dirstream == NULL) |
48 | { |
49 | *dostat = -1; |
50 | return errno; |
51 | } |
52 | |
53 | while ((d = __readdir (dirp: dirstream)) != NULL) |
54 | if (((ino_t) d->d_fileno == myino || *dostat) |
55 | && strcmp (d->d_name, "stdin" ) |
56 | && strcmp (d->d_name, "stdout" ) |
57 | && strcmp (d->d_name, "stderr" )) |
58 | { |
59 | char *cp; |
60 | size_t needed = _D_EXACT_NAMLEN (d) + 1; |
61 | |
62 | if (needed > buflen) |
63 | { |
64 | *dostat = -1; |
65 | (void) __closedir (dirp: dirstream); |
66 | __set_errno (ERANGE); |
67 | return ERANGE; |
68 | } |
69 | |
70 | cp = __stpncpy (&buf[sizeof (dev)], d->d_name, needed); |
71 | cp[0] = '\0'; |
72 | |
73 | if (stat (file: buf, buf: &st) == 0 |
74 | #ifdef _STATBUF_ST_RDEV |
75 | && S_ISCHR (st.st_mode) && st.st_rdev == mydev |
76 | #else |
77 | && (ino_t) d->d_fileno == myino && st.st_dev == mydev |
78 | #endif |
79 | ) |
80 | { |
81 | (void) __closedir (dirp: dirstream); |
82 | __set_errno (save); |
83 | return 0; |
84 | } |
85 | } |
86 | |
87 | (void) __closedir (dirp: dirstream); |
88 | __set_errno (save); |
89 | /* It is not clear what to return in this case. `isatty' says FD |
90 | refers to a TTY but no entry in /dev has this inode. */ |
91 | return ENOTTY; |
92 | } |
93 | |
94 | /* Store at most BUFLEN character of the pathname of the terminal FD is |
95 | open on in BUF. Return 0 on success, otherwise an error number. */ |
96 | int |
97 | __ttyname_r (int fd, char *buf, size_t buflen) |
98 | { |
99 | struct stat st; |
100 | int dostat = 0; |
101 | int save = errno; |
102 | int ret; |
103 | |
104 | /* Test for the absolute minimal size. This makes life easier inside |
105 | the loop. */ |
106 | if (!buf) |
107 | { |
108 | __set_errno (EINVAL); |
109 | return EINVAL; |
110 | } |
111 | |
112 | if (buflen < (int) (sizeof (dev) + 1)) |
113 | { |
114 | __set_errno (ERANGE); |
115 | return ERANGE; |
116 | } |
117 | |
118 | if (!__isatty (fd: fd)) |
119 | { |
120 | __set_errno (ENOTTY); |
121 | return ENOTTY; |
122 | } |
123 | |
124 | if (fstat (fd: fd, buf: &st) < 0) |
125 | return errno; |
126 | |
127 | /* Prepare the result buffer. */ |
128 | memcpy (buf, dev, sizeof (dev) - 1); |
129 | buf[sizeof (dev) - 1] = '/'; |
130 | buflen -= sizeof (dev); |
131 | |
132 | #ifdef _STATBUF_ST_RDEV |
133 | ret = getttyname_r (fd, buf, buflen, mydev: st.st_rdev, myino: st.st_ino, save, |
134 | dostat: &dostat); |
135 | #else |
136 | ret = getttyname_r (fd, buf, buflen, st.st_dev, st.st_ino, save, |
137 | &dostat); |
138 | #endif |
139 | |
140 | if (ret && dostat != -1) |
141 | { |
142 | dostat = 1; |
143 | #ifdef _STATBUF_ST_RDEV |
144 | ret = getttyname_r (fd, buf, buflen, mydev: st.st_rdev, myino: st.st_ino, |
145 | save, dostat: &dostat); |
146 | #else |
147 | ret = getttyname_r (fd, buf, buflen, st.st_dev, st.st_ino, |
148 | save, &dostat); |
149 | #endif |
150 | } |
151 | |
152 | return ret; |
153 | } |
154 | |
155 | weak_alias (__ttyname_r, ttyname_r) |
156 | |