xref: /netbsd/lib/libc/net/linkaddr.c (revision 6550d01e)
1 /*	$NetBSD: linkaddr.c,v 1.14 2005/11/29 03:11:59 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 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 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)linkaddr.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: linkaddr.c,v 1.14 2005/11/29 03:11:59 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include <sys/types.h>
42 #include <sys/socket.h>
43 #include <net/if_dl.h>
44 
45 #include <assert.h>
46 #include <string.h>
47 
48 /* States*/
49 #define NAMING	0
50 #define GOTONE	1
51 #define GOTTWO	2
52 #define RESET	3
53 /* Inputs */
54 #define	DIGIT	(4*0)
55 #define	END	(4*1)
56 #define DELIM	(4*2)
57 #define LETTER	(4*3)
58 
59 void
60 link_addr(addr, sdl)
61 	register const char *addr;
62 	register struct sockaddr_dl *sdl;
63 {
64 	register char *cp = sdl->sdl_data;
65 	char *cplim = sdl->sdl_len + (char *)(void *)sdl;
66 	register int byte = 0, state = NAMING;
67 	register int newaddr = 0;	/* pacify gcc */
68 
69 	_DIAGASSERT(addr != NULL);
70 	_DIAGASSERT(sdl != NULL);
71 
72 	(void)memset(&sdl->sdl_family, 0, (size_t)sdl->sdl_len - 1);
73 	sdl->sdl_family = AF_LINK;
74 	do {
75 		state &= ~LETTER;
76 		if ((*addr >= '0') && (*addr <= '9')) {
77 			newaddr = *addr - '0';
78 		} else if ((*addr >= 'a') && (*addr <= 'f')) {
79 			newaddr = *addr - 'a' + 10;
80 		} else if ((*addr >= 'A') && (*addr <= 'F')) {
81 			newaddr = *addr - 'A' + 10;
82 		} else if (*addr == 0) {
83 			state |= END;
84 		} else if (state == NAMING &&
85 			   (((*addr >= 'A') && (*addr <= 'Z')) ||
86 			   ((*addr >= 'a') && (*addr <= 'z'))))
87 			state |= LETTER;
88 		else
89 			state |= DELIM;
90 		addr++;
91 		switch (state /* | INPUT */) {
92 		case NAMING | DIGIT:
93 		case NAMING | LETTER:
94 			*cp++ = addr[-1];
95 			continue;
96 		case NAMING | DELIM:
97 			state = RESET;
98 			sdl->sdl_nlen = cp - sdl->sdl_data;
99 			continue;
100 		case GOTTWO | DIGIT:
101 			*cp++ = byte;
102 			/* FALLTHROUGH */
103 		case RESET | DIGIT:
104 			state = GOTONE;
105 			byte = newaddr;
106 			continue;
107 		case GOTONE | DIGIT:
108 			state = GOTTWO;
109 			byte = newaddr + (byte << 4);
110 			continue;
111 		default: /* | DELIM */
112 			state = RESET;
113 			*cp++ = byte;
114 			byte = 0;
115 			continue;
116 		case GOTONE | END:
117 		case GOTTWO | END:
118 			*cp++ = byte;
119 			/* FALLTHROUGH */
120 		case RESET | END:
121 			break;
122 		}
123 		break;
124 	} while (cp < cplim);
125 	sdl->sdl_alen = cp - LLADDR(sdl);
126 	newaddr = cp - (char *)(void *)sdl;
127 	if ((size_t) newaddr > sizeof(*sdl))
128 		sdl->sdl_len = newaddr;
129 	return;
130 }
131 
132 static const char hexlist[16] = "0123456789abcdef";
133 
134 char *
135 link_ntoa(sdl)
136 	register const struct sockaddr_dl *sdl;
137 {
138 	static char obuf[64];
139 	register char *out = obuf;
140 	register size_t i;
141 	const u_char *in = (const u_char *)CLLADDR(sdl);
142 	const u_char *inlim = in + sdl->sdl_alen;
143 	int firsttime = 1;
144 
145 	_DIAGASSERT(sdl != NULL);
146 
147 	if (sdl->sdl_nlen) {
148 		(void)memcpy(obuf, sdl->sdl_data, (size_t)sdl->sdl_nlen);
149 		out += sdl->sdl_nlen;
150 		if (sdl->sdl_alen)
151 			*out++ = ':';
152 	}
153 	while (in < inlim) {
154 		if (firsttime)
155 			firsttime = 0;
156 		else
157 			*out++ = '.';
158 		i = *in++;
159 		if (i > 0xf) {
160 			out[1] = hexlist[i & 0xf];
161 			i >>= 4;
162 			out[0] = hexlist[i];
163 			out += 2;
164 		} else
165 			*out++ = hexlist[i];
166 	}
167 	*out = 0;
168 	return (obuf);
169 }
170