1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/* Copyright (C) 1991-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <termios.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <_itoa.h>
#include "ttyname.h"
#if 0
/* Is this used anywhere? It is not exported. */
char *__ttyname;
#endif
static char *getttyname (const char *dev, const struct stat64 *mytty,
int save, int *dostat);
libc_freeres_ptr (static char *getttyname_name);
static char *
attribute_compat_text_section
getttyname (const char *dev, const struct stat64 *mytty, int save, int *dostat)
{
static size_t namelen;
struct stat64 st;
DIR *dirstream;
struct dirent64 *d;
size_t devlen = strlen (dev) + 1;
dirstream = __opendir (dev);
if (dirstream == NULL)
{
*dostat = -1;
return NULL;
}
/* Prepare for the loop. If we already have a buffer copy the directory
name we look at into it. */
if (devlen < namelen)
*((char *) __mempcpy (getttyname_name, dev, devlen - 1)) = '/';
while ((d = __readdir64 (dirstream)) != NULL)
if ((d->d_fileno == mytty->st_ino || *dostat)
&& strcmp (d->d_name, "stdin")
&& strcmp (d->d_name, "stdout")
&& strcmp (d->d_name, "stderr"))
{
size_t dlen = _D_ALLOC_NAMLEN (d);
if (devlen + dlen > namelen)
{
free (getttyname_name);
namelen = 2 * (devlen + dlen); /* Big enough. */
getttyname_name = malloc (namelen);
if (! getttyname_name)
{
*dostat = -1;
/* Perhaps it helps to free the directory stream buffer. */
(void) __closedir (dirstream);
return NULL;
}
*((char *) __mempcpy (getttyname_name, dev, devlen - 1)) = '/';
}
memcpy (&getttyname_name[devlen], d->d_name, dlen);
if (__stat64 (getttyname_name, &st) == 0
&& is_mytty (mytty, &st))
{
(void) __closedir (dirstream);
#if 0
__ttyname = getttyname_name;
#endif
__set_errno (save);
return getttyname_name;
}
}
(void) __closedir (dirstream);
__set_errno (save);
return NULL;
}
/* Static buffer in `ttyname'. */
libc_freeres_ptr (static char *ttyname_buf);
/* Return the pathname of the terminal FD is open on, or NULL on errors.
The returned storage is good only until the next call to this function. */
char *
ttyname (int fd)
{
static size_t buflen;
char procname[30];
struct stat64 st, st1;
int dostat = 0;
int doispty = 0;
char *name;
int save = errno;
struct termios term;
/* isatty check, tcgetattr is used because it sets the correct
errno (EBADF resp. ENOTTY) on error. */
if (__glibc_unlikely (__tcgetattr (fd, &term) < 0))
return NULL;
if (__fstat64 (fd, &st) < 0)
return NULL;
/* We try using the /proc filesystem. */
*_fitoa_word (fd, __stpcpy (procname, "/proc/self/fd/"), 10, 0) = '\0';
if (buflen == 0)
{
buflen = 4095;
ttyname_buf = (char *) malloc (buflen + 1);
if (ttyname_buf == NULL)
{
buflen = 0;
return NULL;
}
}
ssize_t len = __readlink (procname, ttyname_buf, buflen);
if (__glibc_likely (len != -1))
{
if ((size_t) len >= buflen)
return NULL;
#define UNREACHABLE_LEN strlen ("(unreachable)")
if (len > UNREACHABLE_LEN
&& memcmp (ttyname_buf, "(unreachable)", UNREACHABLE_LEN) == 0)
{
memmove (ttyname_buf, ttyname_buf + UNREACHABLE_LEN,
len - UNREACHABLE_LEN);
len -= UNREACHABLE_LEN;
}
/* readlink need not terminate the string. */
ttyname_buf[len] = '\0';
/* Verify readlink result, fall back on iterating through devices. */
if (ttyname_buf[0] == '/'
&& __stat64 (ttyname_buf, &st1) == 0
&& is_mytty (&st, &st1))
return ttyname_buf;
doispty = 1;
}
if (__stat64 ("/dev/pts", &st1) == 0 && S_ISDIR (st1.st_mode))
{
name = getttyname ("/dev/pts", &st, save, &dostat);
}
else
{
__set_errno (save);
name = NULL;
}
if (!name && dostat != -1)
{
name = getttyname ("/dev", &st, save, &dostat);
}
if (!name && dostat != -1)
{
dostat = 1;
name = getttyname ("/dev", &st, save, &dostat);
}
if (!name && doispty && is_pty (&st))
{
/* We failed to figure out the TTY's name, but we can at least
signal that we did verify that it really is a PTY slave.
This happens when we have inherited the file descriptor from
a different mount namespace. */
__set_errno (ENODEV);
return NULL;
}
return name;
}
|
