xref: /freebsd/lib/libc/gen/devname.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
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  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/param.h>
33 #include <sys/sysctl.h>
34 
35 #include <stdio.h>
36 #include <stdint.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <sys/stat.h>
40 
41 char *
42 devname_r(dev_t dev, mode_t type, char *buf, int len)
43 {
44 	int i;
45 	size_t j;
46 
47 	if (dev == NODEV || !(S_ISCHR(type) || S_ISBLK(type))) {
48 		strlcpy(buf, "#NODEV", len);
49 		return (buf);
50 	}
51 
52 	if (S_ISCHR(type)) {
53 		j = len;
54 		i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev));
55 		if (i == 0)
56 			return (buf);
57 	}
58 
59 	/* Finally just format it */
60 	snprintf(buf, len, "#%c:%#jx",
61 	    S_ISCHR(type) ? 'C' : 'B', (uintmax_t)dev);
62 	return (buf);
63 }
64 
65 char *
66 devname(dev_t dev, mode_t type)
67 {
68 	static char buf[SPECNAMELEN + 1];
69 
70 	return (devname_r(dev, type, buf, sizeof(buf)));
71 }
72