1 /* Copyright (C) 1991,92,93,1995-1999,2000,2001 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, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
18
19 #include <errno.h>
20 #include <limits.h>
21 #include <stddef.h>
22 #include <dirent.h>
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <unistd.h>
26 #include <string.h>
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <machine/weakalias.h>
30
31 static int getttyname_r (char *buf, size_t buflen,
32 dev_t mydev, ino64_t myino, int save,
33 int *dostat);
34
35 extern struct dirent64 *__readdir64 (DIR *);
36
37 static int
getttyname_r(char * buf,size_t buflen,dev_t mydev,ino64_t myino,int save,int * dostat)38 getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino,
39 int save, int *dostat)
40 {
41 struct stat64 st;
42 DIR *dirstream;
43 struct dirent64 *d;
44 size_t devlen = strlen (buf);
45
46 dirstream = opendir (buf);
47 if (dirstream == NULL)
48 {
49 *dostat = -1;
50 return errno;
51 }
52
53 while ((d = __readdir64 (dirstream)) != NULL)
54 {
55 if ((d->d_ino == myino || *dostat)
56 && strcmp (d->d_name, "stdin")
57 && strcmp (d->d_name, "stdout")
58 && strcmp (d->d_name, "stderr"))
59 {
60 size_t needed = strlen (d->d_name) + 1;
61
62 if (needed > buflen)
63 {
64 *dostat = -1;
65 (void) closedir (dirstream);
66 __set_errno (ERANGE);
67 return ERANGE;
68 }
69
70 strncpy (buf + devlen, d->d_name, needed);
71
72 if (stat64 (buf, &st) == 0
73 #ifdef _STATBUF_ST_RDEV
74 && S_ISCHR (st.st_mode) && st.st_rdev == mydev
75 #else
76 && d->d_ino == myino && st.st_dev == mydev
77 #endif
78 )
79 {
80 (void) closedir (dirstream);
81 __set_errno (save);
82 return 0;
83 }
84 }
85 }
86
87 (void) closedir (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
__ttyname_r(int fd,char * buf,size_t buflen)97 __ttyname_r (int fd, char *buf, size_t buflen)
98 {
99 char procname[30];
100 struct stat64 st, st1;
101 int dostat = 0;
102 int save = errno;
103 int ret;
104
105 /* Test for the absolute minimal size. This makes life easier inside
106 the loop. */
107 if (!buf)
108 {
109 __set_errno (EINVAL);
110 return EINVAL;
111 }
112
113 if (buflen < sizeof ("/dev/pts/"))
114 {
115 __set_errno (ERANGE);
116 return ERANGE;
117 }
118
119 if (!isatty (fd))
120 {
121 __set_errno (ENOTTY);
122 return ENOTTY;
123 }
124
125 /* We try using the /proc filesystem. */
126 sprintf (procname, "/proc/self/fd/%d", fd);
127
128 ret = readlink (procname, buf, buflen - 1);
129 if (ret != -1 && buf[0] != '[')
130 {
131 buf[ret] = '\0';
132 return 0;
133 }
134 if (ret == -1 && errno == ENAMETOOLONG)
135 {
136 __set_errno (ERANGE);
137 return ERANGE;
138 }
139
140 if (fstat64 (fd, &st) < 0)
141 return errno;
142
143 /* Prepare the result buffer. */
144 memcpy (buf, "/dev/pts/", sizeof ("/dev/pts/"));
145 buflen -= sizeof ("/dev/pts/") - 1;
146
147 if (stat64 (buf, &st1) == 0 && S_ISDIR (st1.st_mode))
148 {
149 #ifdef _STATBUF_ST_RDEV
150 ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save,
151 &dostat);
152 #else
153 ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save,
154 &dostat);
155 #endif
156 }
157 else
158 {
159 __set_errno (save);
160 ret = ENOENT;
161 }
162
163 if (ret && dostat != -1)
164 {
165 buf[sizeof ("/dev/") - 1] = '\0';
166 buflen += sizeof ("pts/") - 1;
167 #ifdef _STATBUF_ST_RDEV
168 ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save,
169 &dostat);
170 #else
171 ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save,
172 &dostat);
173 #endif
174 }
175
176 if (ret && dostat != -1)
177 {
178 buf[sizeof ("/dev/") - 1] = '\0';
179 dostat = 1;
180 #ifdef _STATBUF_ST_RDEV
181 ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino,
182 save, &dostat);
183 #else
184 ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino,
185 save, &dostat);
186 #endif
187 }
188
189 return ret;
190 }
191
192 weak_alias (__ttyname_r, ttyname_r)
193