1/*
2 * Copyright (c) 1988, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if defined(LIBC_SCCS) && !defined(lint)
35static char sccsid[] = "@(#)ttyname.c	8.2 (Berkeley) 1/27/94";
36#endif /* LIBC_SCCS and not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: src/lib/libc/gen/ttyname.c,v 1.16 2004/01/06 18:26:14 nectar Exp $");
39
40#include "namespace.h"
41#include <sys/types.h>
42#include <sys/stat.h>
43#include <fcntl.h>
44#include <dirent.h>
45#include <stdlib.h>
46#include <termios.h>
47#include <unistd.h>
48#include <string.h>
49#include <paths.h>
50#include <pthread.h>
51#include <errno.h>
52#include "un-namespace.h"
53
54#include "libc_private.h"
55
56#ifndef BUILDING_VARIANT
57static pthread_once_t ttyname_buf_control = PTHREAD_ONCE_INIT;
58static char *buf = NULL;
59static char *ttyname_threaded(int fd);
60static char *ttyname_unthreaded(int fd);
61
62static pthread_mutex_t	ttyname_lock = PTHREAD_MUTEX_INITIALIZER;
63static pthread_key_t	ttyname_key;
64static int		ttyname_init = 0;
65
66char *
67ttyname(int fd)
68{
69	char           *ret;
70
71	if (__isthreaded == 0)
72		ret = ttyname_unthreaded(fd);
73	else
74		ret = ttyname_threaded(fd);
75	return (ret);
76}
77#endif /* !BUILDING_VARIANT */
78
79#if __DARWIN_UNIX03
80int
81#else /* !__DARWIN_UNIX03 */
82char *
83#endif /* __DARWIN_UNIX03 */
84ttyname_r(int fd, char *thrbuf, size_t len)
85{
86	struct stat	sb;
87
88#if __DARWIN_UNIX03
89	if (_fstat(fd, &sb) < 0)
90		return (EBADF);
91	/* Must be a terminal. */
92	if (!isatty(fd))
93		return (ENOTTY);
94	/* Must be a character device. */
95	if (!S_ISCHR(sb.st_mode))
96		return (ENOTTY);
97	/* Must have enough room */
98	if (len <= sizeof(_PATH_DEV))
99		return (ERANGE);
100#else /* !__DARWIN_UNIX03 */
101	/* Must be a terminal. */
102	if (!isatty(fd))
103		return (NULL);
104	/* Must be a character device. */
105	if (_fstat(fd, &sb))
106		return (NULL);
107	if (!S_ISCHR(sb.st_mode)) {
108		errno = ENOTTY;
109		return (NULL);
110	}
111	/* Must have enough room */
112	if (len <= sizeof(_PATH_DEV)) {
113		errno = ERANGE;
114		return (NULL);
115	}
116#endif /* __DARWIN_UNIX03 */
117
118	strlcpy(thrbuf, _PATH_DEV, len);
119	if (devname_r(sb.st_rdev, S_IFCHR,
120	    thrbuf + strlen(thrbuf), len - strlen(thrbuf)) == NULL)
121#if __DARWIN_UNIX03
122		return (ERANGE);
123	return (0);
124#else /* !__DARWIN_UNIX03 */
125	{
126		errno = ERANGE;
127		return (NULL);
128	}
129	return (thrbuf);
130#endif /* __DARWIN_UNIX03 */
131}
132
133#ifndef BUILDING_VARIANT
134static char *
135ttyname_threaded(int fd)
136{
137	char	*buf;
138
139	if (ttyname_init == 0) {
140		_pthread_mutex_lock(&ttyname_lock);
141		if (ttyname_init == 0) {
142			/* __PTK_LIBC_TTYNAME_KEY */
143			ttyname_key = __LIBC_PTHREAD_KEY_TTYNAME;
144			if (pthread_key_init_np(ttyname_key, free)) {
145				int save = errno;
146				_pthread_mutex_unlock(&ttyname_lock);
147				errno = save;
148				return (NULL);
149			}
150			ttyname_init = 1;
151		}
152		_pthread_mutex_unlock(&ttyname_lock);
153	}
154
155	/* Must have thread specific data field to put data */
156	if ((buf = _pthread_getspecific(ttyname_key)) == NULL) {
157		if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) {
158			if (_pthread_setspecific(ttyname_key, buf) != 0) {
159				int save = errno;
160				free(buf);
161				errno = save;
162				return (NULL);
163			}
164		} else {
165			return (NULL);
166		}
167	}
168#if __DARWIN_UNIX03
169	return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN) == 0 ? buf : NULL);
170#else /* !__DARWIN_UNIX03 */
171	return (ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN));
172#endif /* __DARWIN_UNIX03 */
173}
174
175static void
176ttyname_buf_allocate(void)
177{
178	buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN);
179}
180
181static char *
182ttyname_unthreaded(int fd)
183{
184	struct stat	sb;
185	struct termios	ttyb;
186
187	/* Must be a terminal. */
188	if (tcgetattr(fd, &ttyb) < 0)
189		return (NULL);
190	/* Must be a character device. */
191	if (_fstat(fd, &sb))
192		return (NULL);
193	if (!S_ISCHR(sb.st_mode)) {
194		errno = ENOTTY;
195		return (NULL);
196	}
197
198	if (pthread_once(&ttyname_buf_control, ttyname_buf_allocate)
199		|| !buf) {
200		errno = ENOMEM;
201		return (NULL);
202	}
203
204	strlcpy(buf, _PATH_DEV, sizeof(_PATH_DEV) + MAXNAMLEN);
205	if (devname_r(sb.st_rdev, S_IFCHR,
206		buf + strlen(buf), sizeof(_PATH_DEV) + MAXNAMLEN - strlen(buf)) == NULL) {
207		errno = ERANGE;
208		return (NULL);
209	}
210	return (buf);
211}
212#endif /* !BUILDING_VARIANT */
213