]>
Commit | Line | Data |
---|---|---|
1 | /* Copyright (C) 1998-2014 Free Software Foundation, Inc. | |
2 | This file is part of the GNU C Library. | |
3 | Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include <errno.h> | |
20 | #include <paths.h> | |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
23 | #include <sys/ioctl.h> | |
24 | #include <sys/stat.h> | |
25 | #include <sys/sysmacros.h> | |
26 | #include <termios.h> | |
27 | #include <unistd.h> | |
28 | ||
29 | #include <_itoa.h> | |
30 | ||
31 | /* Check if DEV corresponds to a master pseudo terminal device. */ | |
32 | #define MASTER_P(Dev) \ | |
33 | (major ((Dev)) == 2 \ | |
34 | || (major ((Dev)) == 4 && minor ((Dev)) >= 128 && minor ((Dev)) < 192) \ | |
35 | || (major ((Dev)) >= 128 && major ((Dev)) < 136)) | |
36 | ||
37 | /* Check if DEV corresponds to a slave pseudo terminal device. */ | |
38 | #define SLAVE_P(Dev) \ | |
39 | (major ((Dev)) == 3 \ | |
40 | || (major ((Dev)) == 4 && minor ((Dev)) >= 192 && minor ((Dev)) < 256) \ | |
41 | || (major ((Dev)) >= 136 && major ((Dev)) < 144)) | |
42 | ||
43 | /* Note that major number 4 corresponds to the old BSD style pseudo | |
44 | terminal devices. As of Linux 2.1.115 these are no longer | |
45 | supported. They have been replaced by major numbers 2 (masters) | |
46 | and 3 (slaves). */ | |
47 | ||
48 | /* Directory where we can find the slave pty nodes. */ | |
49 | #define _PATH_DEVPTS "/dev/pts/" | |
50 | ||
51 | /* The are declared in getpt.c. */ | |
52 | extern const char __libc_ptyname1[] attribute_hidden; | |
53 | extern const char __libc_ptyname2[] attribute_hidden; | |
54 | ||
55 | /* Static buffer for `ptsname'. */ | |
56 | static char buffer[sizeof (_PATH_DEVPTS) + 20]; | |
57 | ||
58 | ||
59 | /* Return the pathname of the pseudo terminal slave associated with | |
60 | the master FD is open on, or NULL on errors. | |
61 | The returned storage is good until the next call to this function. */ | |
62 | char * | |
63 | ptsname (int fd) | |
64 | { | |
65 | return __ptsname_r (fd, buffer, sizeof (buffer)) != 0 ? NULL : buffer; | |
66 | } | |
67 | ||
68 | ||
69 | int | |
70 | __ptsname_internal (int fd, char *buf, size_t buflen, struct stat64 *stp) | |
71 | { | |
72 | int save_errno = errno; | |
73 | unsigned int ptyno; | |
74 | ||
75 | if (buf == NULL) | |
76 | { | |
77 | __set_errno (EINVAL); | |
78 | return EINVAL; | |
79 | } | |
80 | ||
81 | if (!__isatty (fd)) | |
82 | { | |
83 | __set_errno (ENOTTY); | |
84 | return ENOTTY; | |
85 | } | |
86 | ||
87 | #ifdef TIOCGPTN | |
88 | if (__ioctl (fd, TIOCGPTN, &ptyno) == 0) | |
89 | { | |
90 | /* Buffer we use to print the number in. For a maximum size for | |
91 | `int' of 8 bytes we never need more than 20 digits. */ | |
92 | char numbuf[21]; | |
93 | const char *devpts = _PATH_DEVPTS; | |
94 | const size_t devptslen = strlen (_PATH_DEVPTS); | |
95 | char *p; | |
96 | ||
97 | numbuf[sizeof (numbuf) - 1] = '\0'; | |
98 | p = _itoa_word (ptyno, &numbuf[sizeof (numbuf) - 1], 10, 0); | |
99 | ||
100 | if (buflen < devptslen + (&numbuf[sizeof (numbuf)] - p)) | |
101 | { | |
102 | __set_errno (ERANGE); | |
103 | return ERANGE; | |
104 | } | |
105 | ||
106 | memcpy (__stpcpy (buf, devpts), p, &numbuf[sizeof (numbuf)] - p); | |
107 | } | |
108 | else if (errno == EINVAL) | |
109 | #endif | |
110 | { | |
111 | char *p; | |
112 | ||
113 | if (buflen < strlen (_PATH_TTY) + 3) | |
114 | { | |
115 | __set_errno (ERANGE); | |
116 | return ERANGE; | |
117 | } | |
118 | ||
119 | if (__fxstat64 (_STAT_VER, fd, stp) < 0) | |
120 | return errno; | |
121 | ||
122 | /* Check if FD really is a master pseudo terminal. */ | |
123 | if (! MASTER_P (stp->st_rdev)) | |
124 | { | |
125 | __set_errno (ENOTTY); | |
126 | return ENOTTY; | |
127 | } | |
128 | ||
129 | ptyno = minor (stp->st_rdev); | |
130 | ||
131 | if (ptyno / 16 >= strlen (__libc_ptyname1)) | |
132 | { | |
133 | __set_errno (ENOTTY); | |
134 | return ENOTTY; | |
135 | } | |
136 | ||
137 | p = __stpcpy (buf, _PATH_TTY); | |
138 | p[0] = __libc_ptyname1[ptyno / 16]; | |
139 | p[1] = __libc_ptyname2[ptyno % 16]; | |
140 | p[2] = '\0'; | |
141 | } | |
142 | ||
143 | if (__xstat64 (_STAT_VER, buf, stp) < 0) | |
144 | return errno; | |
145 | ||
146 | /* Check if the name we're about to return really corresponds to a | |
147 | slave pseudo terminal. */ | |
148 | if (! S_ISCHR (stp->st_mode) || ! SLAVE_P (stp->st_rdev)) | |
149 | { | |
150 | /* This really is a configuration problem. */ | |
151 | __set_errno (ENOTTY); | |
152 | return ENOTTY; | |
153 | } | |
154 | ||
155 | __set_errno (save_errno); | |
156 | return 0; | |
157 | } | |
158 | ||
159 | ||
160 | /* Store at most BUFLEN characters of the pathname of the slave pseudo | |
161 | terminal associated with the master FD is open on in BUF. | |
162 | Return 0 on success, otherwise an error number. */ | |
163 | int | |
164 | __ptsname_r (int fd, char *buf, size_t buflen) | |
165 | { | |
166 | struct stat64 st; | |
167 | return __ptsname_internal (fd, buf, buflen, &st); | |
168 | } | |
169 | weak_alias (__ptsname_r, ptsname_r) |