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: stable/10/lib/libc/net/linkaddr.c 309690 2016-12-07 23:20:26Z 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 
53 void
link_addr(addr,sdl)54 link_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 
122 static const char hexlist[] = "0123456789abcdef";
123 
124 char *
link_ntoa(sdl)125 link_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 u_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 u_char *)sdl->sdl_data + sdl->sdl_nlen;
149 	inlim = in + sdl->sdl_alen;
150 
151 	while (in < inlim && rem > 1) {
152 		if (in != (const u_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 >> 4];
161 			*out++ = hexlist[i & 0xf];
162 			rem -= 2;
163 		} else {
164 			if (rem < 2)
165 				break;
166 			*out++ = hexlist[i];
167 			rem--;
168 		}
169 	}
170 	*out = 0;
171 	return (obuf);
172 }
173