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
37 static const char hexlist[] = "0123456789abcdef";
38
39 char *
link_ntoa(const struct sockaddr_dl * sdl)40 link_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