ttyname.c revision 146186 
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: head/lib/libc/gen/ttyname.c 146186 2005-05-13 16:27:30Z delphij $");
39
40#include "namespace.h"
41#include <sys/types.h>
42#include <sys/stat.h>
43#include <sys/ioctl.h>
44#include <sys/filio.h>
45#include <fcntl.h>
46#include <dirent.h>
47#include <stdlib.h>
48#include <termios.h>
49#include <unistd.h>
50#include <string.h>
51#include <paths.h>
52#include <pthread.h>
53#include <errno.h>
54#include "un-namespace.h"
55
56#include "libc_private.h"
57
58static char ttyname_buf[sizeof(_PATH_DEV) + MAXNAMLEN];
59
60static pthread_mutex_t	ttyname_lock = PTHREAD_MUTEX_INITIALIZER;
61static pthread_key_t	ttyname_key;
62static int		ttyname_init = 0;
63
64int
65ttyname_r(int fd, char *buf, size_t len)
66{
67	struct stat	sb;
68	struct fiodgname_arg fgn;
69
70	*buf = '\0';
71
72	/* Must be a terminal. */
73	if (!isatty(fd))
74		return (ENOTTY);
75	/* Must be a character device. */
76	if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode))
77		return (ENOTTY);
78	/* Must have enough room */
79	if (len <= sizeof(_PATH_DEV))
80		return (ERANGE);
81
82	strcpy(buf, _PATH_DEV);
83	fgn.len = len - strlen(buf);
84	fgn.buf = buf + strlen(buf);
85	if (!_ioctl(fd, FIODGNAME, &fgn))
86		return (EINVAL);
87	devname_r(sb.st_rdev, S_IFCHR,
88	    buf + strlen(buf), sizeof(buf) - strlen(buf));
89	return (0);
90}
91
92char *
93ttyname(int fd)
94{
95	char	*buf;
96
97	if (__isthreaded == 0) {
98		if (ttyname_r(fd, ttyname_buf, sizeof ttyname_buf) != 0)
99			return (NULL);
100		else
101			return (ttyname_buf);
102	}
103
104	if (ttyname_init == 0) {
105		_pthread_mutex_lock(&ttyname_lock);
106		if (ttyname_init == 0) {
107			if (_pthread_key_create(&ttyname_key, free)) {
108				_pthread_mutex_unlock(&ttyname_lock);
109				return (NULL);
110			}
111			ttyname_init = 1;
112		}
113		_pthread_mutex_unlock(&ttyname_lock);
114	}
115
116	/* Must have thread specific data field to put data */
117	if ((buf = _pthread_getspecific(ttyname_key)) == NULL) {
118		if ((buf = malloc(sizeof(_PATH_DEV) + MAXNAMLEN)) != NULL) {
119			if (_pthread_setspecific(ttyname_key, buf) != 0) {
120				free(buf);
121				return (NULL);
122			}
123		} else {
124			return (NULL);
125		}
126	}
127	ttyname_r(fd, buf, sizeof(_PATH_DEV) + MAXNAMLEN);
128	return (buf);
129}
130
131