xref: /freebsd/lib/libc/net/linkaddr.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
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)
31 static char sccsid[] = "@(#)linkaddr.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <net/if_dl.h>
39 #include <string.h>
40 
41 /* States*/
42 #define NAMING	0
43 #define GOTONE	1
44 #define GOTTWO	2
45 #define RESET	3
46 /* Inputs */
47 #define	DIGIT	(4*0)
48 #define	END	(4*1)
49 #define DELIM	(4*2)
50 #define LETTER	(4*3)
51 
52 void
53 link_addr(addr, sdl)
54 	const char *addr;
55 	struct sockaddr_dl *sdl;
56 {
57 	char *cp = sdl->sdl_data;
58 	char *cplim = sdl->sdl_len + (char *)sdl;
59 	int byte = 0, state = NAMING, new;
60 
61 	bzero((char *)&sdl->sdl_family, sdl->sdl_len - 1);
62 	sdl->sdl_family = AF_LINK;
63 	do {
64 		state &= ~LETTER;
65 		if ((*addr >= '0') && (*addr <= '9')) {
66 			new = *addr - '0';
67 		} else if ((*addr >= 'a') && (*addr <= 'f')) {
68 			new = *addr - 'a' + 10;
69 		} else if ((*addr >= 'A') && (*addr <= 'F')) {
70 			new = *addr - 'A' + 10;
71 		} else if (*addr == 0) {
72 			state |= END;
73 		} else if (state == NAMING &&
74 			   (((*addr >= 'A') && (*addr <= 'Z')) ||
75 			   ((*addr >= 'a') && (*addr <= 'z'))))
76 			state |= LETTER;
77 		else
78 			state |= DELIM;
79 		addr++;
80 		switch (state /* | INPUT */) {
81 		case NAMING | DIGIT:
82 		case NAMING | LETTER:
83 			*cp++ = addr[-1];
84 			continue;
85 		case NAMING | DELIM:
86 			state = RESET;
87 			sdl->sdl_nlen = cp - sdl->sdl_data;
88 			continue;
89 		case GOTTWO | DIGIT:
90 			*cp++ = byte;
91 			/* FALLTHROUGH */
92 		case RESET | DIGIT:
93 			state = GOTONE;
94 			byte = new;
95 			continue;
96 		case GOTONE | DIGIT:
97 			state = GOTTWO;
98 			byte = new + (byte << 4);
99 			continue;
100 		default: /* | DELIM */
101 			state = RESET;
102 			*cp++ = byte;
103 			byte = 0;
104 			continue;
105 		case GOTONE | END:
106 		case GOTTWO | END:
107 			*cp++ = byte;
108 			/* FALLTHROUGH */
109 		case RESET | END:
110 			break;
111 		}
112 		break;
113 	} while (cp < cplim);
114 	sdl->sdl_alen = cp - LLADDR(sdl);
115 	new = cp - (char *)sdl;
116 	if (new > sizeof(*sdl))
117 		sdl->sdl_len = new;
118 	return;
119 }
120 
121 static const char hexlist[] = "0123456789abcdef";
122 
123 char *
124 link_ntoa(sdl)
125 	const struct sockaddr_dl *sdl;
126 {
127 	static char obuf[64];
128 	char *out = obuf;
129 	int i;
130 	u_char *in = (u_char *)LLADDR(sdl);
131 	u_char *inlim = in + sdl->sdl_alen;
132 	int firsttime = 1;
133 
134 	if (sdl->sdl_nlen) {
135 		bcopy(sdl->sdl_data, obuf, sdl->sdl_nlen);
136 		out += sdl->sdl_nlen;
137 		if (sdl->sdl_alen)
138 			*out++ = ':';
139 	}
140 	while (in < inlim) {
141 		if (firsttime)
142 			firsttime = 0;
143 		else
144 			*out++ = '.';
145 		i = *in++;
146 		if (i > 0xf) {
147 			out[1] = hexlist[i & 0xf];
148 			i >>= 4;
149 			out[0] = hexlist[i];
150 			out += 2;
151 		} else
152 			*out++ = hexlist[i];
153 	}
154 	*out = 0;
155 	return (obuf);
156 }
157