xref: /openbsd-src/lib/libc/net/linkaddr.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: linkaddr.c,v 1.5 2005/08/06 20:30:03 espie 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 /* States*/
37 #define NAMING	0
38 #define GOTONE	1
39 #define GOTTWO	2
40 #define RESET	3
41 /* Inputs */
42 #define	DIGIT	(4*0)
43 #define	END	(4*1)
44 #define DELIM	(4*2)
45 #define LETTER	(4*3)
46 
47 void
48 link_addr(const char *addr, struct sockaddr_dl *sdl)
49 {
50 	char *cp = sdl->sdl_data;
51 	char *cplim = sdl->sdl_len + (char *)sdl;
52 	int byte = 0, state = NAMING, new;
53 
54 	bzero((char *)&sdl->sdl_family, sdl->sdl_len - 1);
55 	sdl->sdl_family = AF_LINK;
56 	do {
57 		state &= ~LETTER;
58 		if ((*addr >= '0') && (*addr <= '9')) {
59 			new = *addr - '0';
60 		} else if ((*addr >= 'a') && (*addr <= 'f')) {
61 			new = *addr - 'a' + 10;
62 		} else if ((*addr >= 'A') && (*addr <= 'F')) {
63 			new = *addr - 'A' + 10;
64 		} else if (*addr == 0) {
65 			state |= END;
66 		} else if (state == NAMING &&
67 			   (((*addr >= 'A') && (*addr <= 'Z')) ||
68 			   ((*addr >= 'a') && (*addr <= 'z'))))
69 			state |= LETTER;
70 		else
71 			state |= DELIM;
72 		addr++;
73 		switch (state /* | INPUT */) {
74 		case NAMING | DIGIT:
75 		case NAMING | LETTER:
76 			*cp++ = addr[-1];
77 			continue;
78 		case NAMING | DELIM:
79 			state = RESET;
80 			sdl->sdl_nlen = cp - sdl->sdl_data;
81 			continue;
82 		case GOTTWO | DIGIT:
83 			*cp++ = byte;
84 			/* FALLTHROUGH */
85 		case RESET | DIGIT:
86 			state = GOTONE;
87 			byte = new;
88 			continue;
89 		case GOTONE | DIGIT:
90 			state = GOTTWO;
91 			byte = new + (byte << 4);
92 			continue;
93 		default: /* | DELIM */
94 			state = RESET;
95 			*cp++ = byte;
96 			byte = 0;
97 			continue;
98 		case GOTONE | END:
99 		case GOTTWO | END:
100 			*cp++ = byte;
101 			/* FALLTHROUGH */
102 		case RESET | END:
103 			break;
104 		}
105 		break;
106 	} while (cp < cplim);
107 	sdl->sdl_alen = cp - LLADDR(sdl);
108 	new = cp - (char *)sdl;
109 	if (new > sizeof(*sdl))
110 		sdl->sdl_len = new;
111 	return;
112 }
113 
114 static char hexlist[] = "0123456789abcdef";
115 
116 char *
117 link_ntoa(const struct sockaddr_dl *sdl)
118 {
119 	static char obuf[64];
120 	char *out = obuf;
121 	int i;
122 	u_char *in = (u_char *)LLADDR(sdl);
123 	u_char *inlim = in + sdl->sdl_alen;
124 	int firsttime = 1;
125 
126 	if (sdl->sdl_nlen) {
127 		bcopy(sdl->sdl_data, obuf, sdl->sdl_nlen);
128 		out += sdl->sdl_nlen;
129 		if (sdl->sdl_alen)
130 			*out++ = ':';
131 	}
132 	while (in < inlim) {
133 		if (firsttime)
134 			firsttime = 0;
135 		else
136 			*out++ = '.';
137 		i = *in++;
138 		if (i > 0xf) {
139 			out[1] = hexlist[i & 0xf];
140 			i >>= 4;
141 			out[0] = hexlist[i];
142 			out += 2;
143 		} else
144 			*out++ = hexlist[i];
145 	}
146 	*out = 0;
147 	return (obuf);
148 }
149