1 | /* Copyright (C) 1991-2016 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 | <http://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 <termios.h> |
25 | #include <unistd.h> |
26 | #include <string.h> |
27 | #include <stdlib.h> |
28 | |
29 | #include <_itoa.h> |
30 | |
31 | static int getttyname_r (char *buf, size_t buflen, |
32 | dev_t mydev, ino64_t myino, int save, |
33 | int *dostat) internal_function; |
34 | |
35 | static int |
36 | internal_function attribute_compat_text_section |
37 | getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino, |
38 | int save, int *dostat) |
39 | { |
40 | struct stat64 st; |
41 | DIR *dirstream; |
42 | struct dirent64 *d; |
43 | size_t devlen = strlen (buf); |
44 | |
45 | dirstream = __opendir (buf); |
46 | if (dirstream == NULL) |
47 | { |
48 | *dostat = -1; |
49 | return errno; |
50 | } |
51 | |
52 | while ((d = __readdir64 (dirstream)) != NULL) |
53 | if ((d->d_fileno == myino || *dostat) |
54 | && strcmp (d->d_name, "stdin" ) |
55 | && strcmp (d->d_name, "stdout" ) |
56 | && strcmp (d->d_name, "stderr" )) |
57 | { |
58 | char *cp; |
59 | size_t needed = _D_EXACT_NAMLEN (d) + 1; |
60 | |
61 | if (needed > buflen) |
62 | { |
63 | *dostat = -1; |
64 | (void) __closedir (dirstream); |
65 | __set_errno (ERANGE); |
66 | return ERANGE; |
67 | } |
68 | |
69 | cp = __stpncpy (buf + devlen, d->d_name, needed); |
70 | cp[0] = '\0'; |
71 | |
72 | if (__xstat64 (_STAT_VER, buf, &st) == 0 |
73 | #ifdef _STATBUF_ST_RDEV |
74 | && S_ISCHR (st.st_mode) && st.st_rdev == mydev |
75 | #else |
76 | && d->d_fileno == myino && st.st_dev == mydev |
77 | #endif |
78 | ) |
79 | { |
80 | (void) __closedir (dirstream); |
81 | __set_errno (save); |
82 | return 0; |
83 | } |
84 | } |
85 | |
86 | (void) __closedir (dirstream); |
87 | __set_errno (save); |
88 | /* It is not clear what to return in this case. `isatty' says FD |
89 | refers to a TTY but no entry in /dev has this inode. */ |
90 | return ENOTTY; |
91 | } |
92 | |
93 | /* Store at most BUFLEN character of the pathname of the terminal FD is |
94 | open on in BUF. Return 0 on success, otherwise an error number. */ |
95 | int |
96 | __ttyname_r (int fd, char *buf, size_t buflen) |
97 | { |
98 | char procname[30]; |
99 | struct stat64 st, st1; |
100 | int dostat = 0; |
101 | int save = errno; |
102 | |
103 | /* Test for the absolute minimal size. This makes life easier inside |
104 | the loop. */ |
105 | if (!buf) |
106 | { |
107 | __set_errno (EINVAL); |
108 | return EINVAL; |
109 | } |
110 | |
111 | if (buflen < sizeof ("/dev/pts/" )) |
112 | { |
113 | __set_errno (ERANGE); |
114 | return ERANGE; |
115 | } |
116 | |
117 | /* isatty check, tcgetattr is used because it sets the correct |
118 | errno (EBADF resp. ENOTTY) on error. */ |
119 | struct termios term; |
120 | if (__glibc_unlikely (__tcgetattr (fd, &term) < 0)) |
121 | return errno; |
122 | |
123 | if (__fxstat64 (_STAT_VER, fd, &st) < 0) |
124 | return errno; |
125 | |
126 | /* We try using the /proc filesystem. */ |
127 | *_fitoa_word (fd, __stpcpy (procname, "/proc/self/fd/" ), 10, 0) = '\0'; |
128 | |
129 | ssize_t ret = __readlink (procname, buf, buflen - 1); |
130 | if (__glibc_unlikely (ret == -1 && errno == ENAMETOOLONG)) |
131 | { |
132 | __set_errno (ERANGE); |
133 | return ERANGE; |
134 | } |
135 | |
136 | if (__glibc_likely (ret != -1)) |
137 | { |
138 | #define UNREACHABLE_LEN strlen ("(unreachable)") |
139 | if (ret > UNREACHABLE_LEN |
140 | && memcmp (buf, "(unreachable)" , UNREACHABLE_LEN) == 0) |
141 | { |
142 | memmove (buf, buf + UNREACHABLE_LEN, ret - UNREACHABLE_LEN); |
143 | ret -= UNREACHABLE_LEN; |
144 | } |
145 | |
146 | /* readlink need not terminate the string. */ |
147 | buf[ret] = '\0'; |
148 | |
149 | /* Verify readlink result, fall back on iterating through devices. */ |
150 | if (buf[0] == '/' |
151 | && __xstat64 (_STAT_VER, buf, &st1) == 0 |
152 | #ifdef _STATBUF_ST_RDEV |
153 | && S_ISCHR (st1.st_mode) |
154 | && st1.st_rdev == st.st_rdev |
155 | #else |
156 | && st1.st_ino == st.st_ino |
157 | && st1.st_dev == st.st_dev |
158 | #endif |
159 | ) |
160 | return 0; |
161 | } |
162 | |
163 | /* Prepare the result buffer. */ |
164 | memcpy (buf, "/dev/pts/" , sizeof ("/dev/pts/" )); |
165 | buflen -= sizeof ("/dev/pts/" ) - 1; |
166 | |
167 | if (__xstat64 (_STAT_VER, buf, &st1) == 0 && S_ISDIR (st1.st_mode)) |
168 | { |
169 | #ifdef _STATBUF_ST_RDEV |
170 | ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save, |
171 | &dostat); |
172 | #else |
173 | ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save, |
174 | &dostat); |
175 | #endif |
176 | } |
177 | else |
178 | { |
179 | __set_errno (save); |
180 | ret = ENOENT; |
181 | } |
182 | |
183 | if (ret && dostat != -1) |
184 | { |
185 | buf[sizeof ("/dev/" ) - 1] = '\0'; |
186 | buflen += sizeof ("pts/" ) - 1; |
187 | #ifdef _STATBUF_ST_RDEV |
188 | ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save, |
189 | &dostat); |
190 | #else |
191 | ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save, |
192 | &dostat); |
193 | #endif |
194 | } |
195 | |
196 | if (ret && dostat != -1) |
197 | { |
198 | buf[sizeof ("/dev/" ) - 1] = '\0'; |
199 | dostat = 1; |
200 | #ifdef _STATBUF_ST_RDEV |
201 | ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, |
202 | save, &dostat); |
203 | #else |
204 | ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, |
205 | save, &dostat); |
206 | #endif |
207 | } |
208 | |
209 | return ret; |
210 | } |
211 | |
212 | weak_alias (__ttyname_r, ttyname_r) |
213 | |