xref: /openbsd/lib/libc/net/linkaddr.c (revision 264ca280)
1 /*	$OpenBSD: linkaddr.c,v 1.6 2015/09/10 08:55:03 mpi Exp $ */
2 /*-
3  * Copyright (c) 1990, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <net/if_dl.h>
34 #include <string.h>
35 
36 static char hexlist[] = "0123456789abcdef";
37 
38 char *
39 link_ntoa(const struct sockaddr_dl *sdl)
40 {
41 	static char obuf[64];
42 	char *out = obuf;
43 	int i;
44 	u_char *in = (u_char *)LLADDR(sdl);
45 	u_char *inlim = in + sdl->sdl_alen;
46 	int firsttime = 1;
47 
48 	if (sdl->sdl_nlen) {
49 		bcopy(sdl->sdl_data, obuf, sdl->sdl_nlen);
50 		out += sdl->sdl_nlen;
51 		if (sdl->sdl_alen)
52 			*out++ = ':';
53 	}
54 	while (in < inlim) {
55 		if (firsttime)
56 			firsttime = 0;
57 		else
58 			*out++ = '.';
59 		i = *in++;
60 		if (i > 0xf) {
61 			out[1] = hexlist[i & 0xf];
62 			i >>= 4;
63 			out[0] = hexlist[i];
64 			out += 2;
65 		} else
66 			*out++ = hexlist[i];
67 	}
68 	*out = 0;
69 	return (obuf);
70 }
71