1 /*
2 * Copyright (c) 2009 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Alex Hornung <ahornung@gmail.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34 #include "namespace.h"
35 #include <sys/types.h>
36 #include <fcntl.h>
37 #include <dirent.h>
38 #include <stdlib.h>
39 #include <termios.h>
40 #include <unistd.h>
41 #include <string.h>
42 #include <paths.h>
43 #include <errno.h>
44 #include <limits.h>
45 #include <machine/stdint.h>
46 #include <sys/stat.h>
47 #include <sys/ioctl.h>
48 #include "reentrant.h"
49 #include "un-namespace.h"
50
51 #include "libc_private.h"
52
53 static char fdevname_buf[sizeof(_PATH_DEV) + NAME_MAX];
54
55 static once_t fdevname_init_once = ONCE_INITIALIZER;
56 static thread_key_t fdevname_key;
57 static int fdevname_keycreated = 0;
58
59 int
fdevname_r(int fd,char * buf,size_t len)60 fdevname_r(int fd, char *buf, size_t len)
61 {
62 struct stat sb;
63 struct fiodname_args fa;
64
65 *buf = '\0';
66
67 /* Must be a valid file descriptor */
68 if (_fstat(fd, &sb))
69 return (EBADF);
70
71 /* Must be a character device */
72 if (!S_ISCHR(sb.st_mode))
73 return (EINVAL);
74
75 fa.len = len;
76 fa.name = buf;
77 if (_ioctl(fd, FIODNAME, &fa) == -1) {
78 return ERANGE;
79 }
80 return (0);
81 }
82
83 static void
fdevname_keycreate(void)84 fdevname_keycreate(void)
85 {
86 fdevname_keycreated = (thr_keycreate(&fdevname_key, free) == 0);
87 }
88
89 char *
fdevname(int fd)90 fdevname(int fd)
91 {
92 char *buf;
93 int error;
94
95 if (thr_main() != 0)
96 buf = fdevname_buf;
97 else {
98 if (thr_once(&fdevname_init_once, fdevname_keycreate) != 0 ||
99 !fdevname_keycreated)
100 return (NULL);
101 if ((buf = thr_getspecific(fdevname_key)) == NULL) {
102 if ((buf = malloc(sizeof fdevname_buf)) == NULL)
103 return (NULL);
104 if (thr_setspecific(fdevname_key, buf) != 0) {
105 free(buf);
106 return (NULL);
107 }
108 }
109 }
110
111 if (((error = fdevname_r(fd, buf, sizeof fdevname_buf))) != 0) {
112 errno = error;
113 return (NULL);
114 }
115 return (buf);
116 }
117