linkaddr.c revision 309636 
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)linkaddr.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: releng/10.1/lib/libc/net/linkaddr.c 309636 2016-12-06 18:49:59Z glebius $");
35
36#include <sys/types.h>
37#include <sys/socket.h>
38#include <net/if.h>
39#include <net/if_dl.h>
40#include <string.h>
41
42/* States*/
43#define NAMING	0
44#define GOTONE	1
45#define GOTTWO	2
46#define RESET	3
47/* Inputs */
48#define	DIGIT	(4*0)
49#define	END	(4*1)
50#define DELIM	(4*2)
51#define LETTER	(4*3)
52
53void
54link_addr(addr, sdl)
55	const char *addr;
56	struct sockaddr_dl *sdl;
57{
58	char *cp = sdl->sdl_data;
59	char *cplim = sdl->sdl_len + (char *)sdl;
60	int byte = 0, state = NAMING, new;
61
62	bzero((char *)&sdl->sdl_family, sdl->sdl_len - 1);
63	sdl->sdl_family = AF_LINK;
64	do {
65		state &= ~LETTER;
66		if ((*addr >= '0') && (*addr <= '9')) {
67			new = *addr - '0';
68		} else if ((*addr >= 'a') && (*addr <= 'f')) {
69			new = *addr - 'a' + 10;
70		} else if ((*addr >= 'A') && (*addr <= 'F')) {
71			new = *addr - 'A' + 10;
72		} else if (*addr == 0) {
73			state |= END;
74		} else if (state == NAMING &&
75			   (((*addr >= 'A') && (*addr <= 'Z')) ||
76			   ((*addr >= 'a') && (*addr <= 'z'))))
77			state |= LETTER;
78		else
79			state |= DELIM;
80		addr++;
81		switch (state /* | INPUT */) {
82		case NAMING | DIGIT:
83		case NAMING | LETTER:
84			*cp++ = addr[-1];
85			continue;
86		case NAMING | DELIM:
87			state = RESET;
88			sdl->sdl_nlen = cp - sdl->sdl_data;
89			continue;
90		case GOTTWO | DIGIT:
91			*cp++ = byte;
92			/* FALLTHROUGH */
93		case RESET | DIGIT:
94			state = GOTONE;
95			byte = new;
96			continue;
97		case GOTONE | DIGIT:
98			state = GOTTWO;
99			byte = new + (byte << 4);
100			continue;
101		default: /* | DELIM */
102			state = RESET;
103			*cp++ = byte;
104			byte = 0;
105			continue;
106		case GOTONE | END:
107		case GOTTWO | END:
108			*cp++ = byte;
109			/* FALLTHROUGH */
110		case RESET | END:
111			break;
112		}
113		break;
114	} while (cp < cplim);
115	sdl->sdl_alen = cp - LLADDR(sdl);
116	new = cp - (char *)sdl;
117	if (new > sizeof(*sdl))
118		sdl->sdl_len = new;
119	return;
120}
121
122static const char hexlist[] = "0123456789abcdef";
123
124char *
125link_ntoa(sdl)
126	const struct sockaddr_dl *sdl;
127{
128	static char obuf[64];
129	_Static_assert(sizeof(obuf) >= IFNAMSIZ + 20, "obuf is too small");
130	char *out;
131	const char *in, *inlim;
132	int namelen, i, rem;
133
134	namelen = (sdl->sdl_nlen <= IFNAMSIZ) ? sdl->sdl_nlen : IFNAMSIZ;
135
136	out = obuf;
137	rem = sizeof(obuf);
138	if (namelen > 0) {
139		bcopy(sdl->sdl_data, out, namelen);
140		out += namelen;
141		rem -= namelen;
142		if (sdl->sdl_alen > 0) {
143			*out++ = ':';
144			rem--;
145		}
146	}
147
148	in = (const char *)sdl->sdl_data + sdl->sdl_nlen;
149	inlim = in + sdl->sdl_alen;
150
151	while (in < inlim && rem > 1) {
152		if (in != (const char *)sdl->sdl_data + sdl->sdl_nlen) {
153			*out++ = '.';
154			rem--;
155		}
156		i = *in++;
157		if (i > 0xf) {
158			if (rem < 3)
159				break;
160			*out++ = hexlist[i & 0xf];
161			i >>= 4;
162			*out++ = hexlist[i];
163			rem -= 2;
164		} else {
165			if (rem < 2)
166				break;
167			*out++ = hexlist[i];
168			rem++;
169		}
170	}
171	*out = 0;
172	return (obuf);
173}
174