xref: /freebsd/lib/libc/net/linkaddr.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
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(const char *addr, struct sockaddr_dl *sdl)
54 {
55 	char *cp = sdl->sdl_data;
56 	char *cplim = sdl->sdl_len + (char *)sdl;
57 	int byte = 0, state = NAMING, new;
58 
59 	bzero((char *)&sdl->sdl_family, sdl->sdl_len - 1);
60 	sdl->sdl_family = AF_LINK;
61 	do {
62 		state &= ~LETTER;
63 		if ((*addr >= '0') && (*addr <= '9')) {
64 			new = *addr - '0';
65 		} else if ((*addr >= 'a') && (*addr <= 'f')) {
66 			new = *addr - 'a' + 10;
67 		} else if ((*addr >= 'A') && (*addr <= 'F')) {
68 			new = *addr - 'A' + 10;
69 		} else if (*addr == 0) {
70 			state |= END;
71 		} else if (state == NAMING &&
72 			   (((*addr >= 'A') && (*addr <= 'Z')) ||
73 			   ((*addr >= 'a') && (*addr <= 'z'))))
74 			state |= LETTER;
75 		else
76 			state |= DELIM;
77 		addr++;
78 		switch (state /* | INPUT */) {
79 		case NAMING | DIGIT:
80 		case NAMING | LETTER:
81 			*cp++ = addr[-1];
82 			continue;
83 		case NAMING | DELIM:
84 			state = RESET;
85 			sdl->sdl_nlen = cp - sdl->sdl_data;
86 			continue;
87 		case GOTTWO | DIGIT:
88 			*cp++ = byte;
89 			/* FALLTHROUGH */
90 		case RESET | DIGIT:
91 			state = GOTONE;
92 			byte = new;
93 			continue;
94 		case GOTONE | DIGIT:
95 			state = GOTTWO;
96 			byte = new + (byte << 4);
97 			continue;
98 		default: /* | DELIM */
99 			state = RESET;
100 			*cp++ = byte;
101 			byte = 0;
102 			continue;
103 		case GOTONE | END:
104 		case GOTTWO | END:
105 			*cp++ = byte;
106 			/* FALLTHROUGH */
107 		case RESET | END:
108 			break;
109 		}
110 		break;
111 	} while (cp < cplim);
112 	sdl->sdl_alen = cp - LLADDR(sdl);
113 	new = cp - (char *)sdl;
114 	if (new > sizeof(*sdl))
115 		sdl->sdl_len = new;
116 	return;
117 }
118 
119 static const char hexlist[] = "0123456789abcdef";
120 
121 char *
122 link_ntoa(const struct sockaddr_dl *sdl)
123 {
124 	static char obuf[64];
125 	char *out = obuf;
126 	int i;
127 	u_char *in = (u_char *)LLADDR(sdl);
128 	u_char *inlim = in + sdl->sdl_alen;
129 	int firsttime = 1;
130 
131 	if (sdl->sdl_nlen) {
132 		bcopy(sdl->sdl_data, obuf, sdl->sdl_nlen);
133 		out += sdl->sdl_nlen;
134 		if (sdl->sdl_alen)
135 			*out++ = ':';
136 	}
137 	while (in < inlim) {
138 		if (firsttime)
139 			firsttime = 0;
140 		else
141 			*out++ = '.';
142 		i = *in++;
143 		if (i > 0xf) {
144 			out[1] = hexlist[i & 0xf];
145 			i >>= 4;
146 			out[0] = hexlist[i];
147 			out += 2;
148 		} else
149 			*out++ = hexlist[i];
150 	}
151 	*out = 0;
152 	return (obuf);
153 }
154