xref: /freebsd/lib/libc/gen/devname.c (revision f5147e312f43a9050468de539aeafa072caa1a60)
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 #if defined(LIBC_SCCS) && !defined(lint)
33 static char sccsid[] = "@(#)devname.c	8.2 (Berkeley) 4/29/95";
34 #endif /* LIBC_SCCS and not lint */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37 
38 #include <sys/param.h>
39 #include <sys/sysctl.h>
40 
41 #include <stdio.h>
42 #include <stdint.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <sys/stat.h>
46 
47 char *
48 devname_r(dev_t dev, mode_t type, char *buf, int len)
49 {
50 	int i;
51 	size_t j;
52 
53 	if (dev == NODEV || !(S_ISCHR(type) || S_ISBLK(dev))) {
54 		strlcpy(buf, "#NODEV", len);
55 		return (buf);
56 	}
57 
58 	if (S_ISCHR(type)) {
59 		j = len;
60 		i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev));
61 		if (i == 0)
62 			return (buf);
63 	}
64 
65 	/* Finally just format it */
66 	snprintf(buf, len, "#%c:%#jx",
67 	    S_ISCHR(type) ? 'C' : 'B', (uintmax_t)dev);
68 	return (buf);
69 }
70 
71 char *
72 devname(dev_t dev, mode_t type)
73 {
74 	static char buf[SPECNAMELEN + 1];
75 
76 	return (devname_r(dev, type, buf, sizeof(buf)));
77 }
78