1/*	$OpenBSD: linkaddr.c,v 1.9 2016/12/08 03:20:50 millert 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.h>
34#include <net/if_dl.h>
35#include <string.h>
36
37static const char hexlist[] = "0123456789abcdef";
38
39char *
40link_ntoa(const struct sockaddr_dl *sdl)
41{
42	static char obuf[64];
43	char *out;
44	const u_char *in, *inlim;
45	int namelen, i, rem;
46
47	namelen = (sdl->sdl_nlen <= IFNAMSIZ) ? sdl->sdl_nlen : IFNAMSIZ;
48
49	out = obuf;
50	rem = sizeof(obuf);
51	if (namelen > 0) {
52		memcpy(out, sdl->sdl_data, namelen);
53		out += namelen;
54		rem -= namelen;
55		if (sdl->sdl_alen > 0) {
56			*out++ = ':';
57			rem--;
58		}
59	}
60
61	in = (const u_char *)sdl->sdl_data + sdl->sdl_nlen;
62	inlim = in + sdl->sdl_alen;
63
64	while (in < inlim && rem > 1) {
65		if (in != (const u_char *)sdl->sdl_data + sdl->sdl_nlen) {
66			*out++ = '.';
67			rem--;
68		}
69		i = *in++;
70		if (i > 0xf) {
71			if (rem < 3)
72				break;
73			*out++ = hexlist[i >> 4];
74			*out++ = hexlist[i & 0xf];
75			rem -= 2;
76		} else {
77			if (rem < 2)
78				break;
79			*out++ = hexlist[i];
80			rem--;
81		}
82	}
83	*out = 0;
84	return (obuf);
85}
86