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. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)ttyname.c 8.2 (Berkeley) 1/27/94
30 * $FreeBSD: src/lib/libc/gen/ttyname.c,v 1.24 2007/01/09 00:27:55 imp Exp $
31 */
32
33 #include "namespace.h"
34 #include <sys/types.h>
35 #include <fcntl.h>
36 #include <dirent.h>
37 #include <stdlib.h>
38 #include <termios.h>
39 #include <unistd.h>
40 #include <string.h>
41 #include <paths.h>
42 #include <errno.h>
43 #include <limits.h>
44 #include <machine/stdint.h>
45 #include <sys/stat.h>
46 #include <sys/ioctl.h>
47 #include "reentrant.h"
48 #include "un-namespace.h"
49
50 #include "libc_private.h"
51
52 #define TTYNAME_DEVFS_COMPAT 1
53
54 static char ttyname_buf[sizeof(_PATH_DEV) + NAME_MAX];
55
56 static once_t ttyname_init_once = ONCE_INITIALIZER;
57 static thread_key_t ttyname_key;
58 static int ttyname_keycreated = 0;
59
60 int
ttyname_r(int fd,char * buf,size_t len)61 ttyname_r(int fd, char *buf, size_t len)
62 {
63 struct stat sb;
64 struct fiodname_args fa;
65 size_t used;
66
67 *buf = '\0';
68
69 /* Must be a valid file descriptor */
70 if (_fstat(fd, &sb))
71 return (EBADF);
72 /* Must be a character device */
73 if (!S_ISCHR(sb.st_mode))
74 return (ENOTTY);
75 /* Must be a terminal. */
76 if (!isatty(fd))
77 return (ENOTTY);
78 /* Must have enough room */
79 if (len <= sizeof(_PATH_DEV))
80 return (ERANGE);
81
82 strcpy(buf, _PATH_DEV);
83 used = strlen(buf);
84 fa.len = len - used;
85 fa.name = buf + used;
86 if (_ioctl(fd, FIODNAME, &fa) == -1) {
87 #ifdef TTYNAME_DEVFS_COMPAT
88 /* If compat mode is set, fall back to old method */
89 devname_r(sb.st_rdev, S_IFCHR, buf + used, len - used);
90 #else
91 return ERANGE;
92 #endif
93 }
94 return (0);
95 }
96
97 static void
ttyname_keycreate(void)98 ttyname_keycreate(void)
99 {
100 ttyname_keycreated = (thr_keycreate(&ttyname_key, free) == 0);
101 }
102
103 char *
ttyname(int fd)104 ttyname(int fd)
105 {
106 int error;
107 char *buf;
108
109 if (thr_main() != 0)
110 buf = ttyname_buf;
111 else {
112 if (thr_once(&ttyname_init_once, ttyname_keycreate) != 0 ||
113 !ttyname_keycreated)
114 return (NULL);
115 if ((buf = thr_getspecific(ttyname_key)) == NULL) {
116 if ((buf = malloc(sizeof ttyname_buf)) == NULL)
117 return (NULL);
118 if (thr_setspecific(ttyname_key, buf) != 0) {
119 free(buf);
120 return (NULL);
121 }
122 }
123 }
124
125 if (((error = ttyname_r(fd, buf, sizeof ttyname_buf))) != 0) {
126 errno = error;
127 return (NULL);
128 }
129 return (buf);
130 }
131