xref: /illumos-gate/usr/src/lib/libsocket/inet/link_addr.c (revision 43449cdcd0600512dd862537f2cf014140dd0844)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * Function implementations to convert between link layer addresses and
31  * ascii representations of the form "x:x:x:...:x:x:x" where x is a hex
32  * number between 0x00 and 0xff; the bytes are always in network order.
33  */
34 
35 #include <stdio.h>
36 #include <ctype.h>
37 #include <stdlib.h>
38 #include <sys/types.h>
39 #include <net/if_dl.h>
40 
41 /*
42  * Converts a "size" bytes long mac address to its string representation.
43  * Currently, the "mactype" is unused, but in the future, the string
44  * can be modulated by "mactype" (IFT_* value from <net/if_types.h>)
45  */
46 /* ARGSUSED */
47 char *
48 _link_ntoa(const unsigned char *macaddr, char *str, int size, int mactype)
49 {
50 	char *buf;
51 	int i, n;
52 
53 	if (((buf = str) == NULL) &&
54 	    ((buf = malloc(3 * size)) == NULL))
55 		return (NULL);
56 	n = sprintf(buf, "%x", *macaddr++);
57 	for (i = 0; i < (size - 1); i++)
58 		n += sprintf(buf+n, ":%x", *macaddr++);
59 	return (buf);
60 }
61 
62 /*
63  * Converts a string possibly representing a link address into its
64  * bit format, returning length of the address in bytes.
65  */
66 uchar_t *
67 _link_aton(const char *ascaddr, int *maclen)
68 {
69 	unsigned char cval, num = 0;
70 	int idx = 0, numcolons = 0, digits = 0;
71 	uchar_t *netaddr;
72 	const char *cptr;
73 	char lastc = ':';
74 
75 	while (isspace(*ascaddr))
76 		ascaddr++;
77 
78 	/*
79 	 * Find how many :'s in the string. Also sanity check
80 	 * the string for valid hex chars, absence of white
81 	 * spaces, not starting or ending with :, absence of
82 	 * consecutive :'s, excessive digits per element
83 	 * and non-null string.
84 	 */
85 	cptr = ascaddr;
86 	while ((cval = *cptr++) != '\0') {
87 		if (cval == ':') {
88 			if (lastc == ':')
89 				break;
90 			numcolons++;
91 			digits = 0;
92 		} else if (!isxdigit(cval)) {
93 			break;
94 		} else {
95 			digits++;
96 		}
97 
98 		if (digits > 2)
99 			break;
100 
101 		lastc = cval;
102 	}
103 	if ((lastc == ':') || (cval != '\0' && !isspace(cval)) ||
104 	    (digits > 2)) {
105 		*maclen = -1;
106 		return (NULL);
107 	}
108 
109 	if ((netaddr = malloc(numcolons + 1)) == NULL) {
110 		*maclen = 0;
111 		return (NULL);
112 	}
113 
114 	for (;;) {
115 		cval = *ascaddr++;
116 		if (isdigit(cval)) {
117 			num = (num << 4) | (cval - '0');
118 		} else if (isxdigit(cval)) {
119 			num = (num << 4) |
120 			    (cval - (isupper(cval) ? 'A' : 'a') + 10);
121 		} else if (cval == ':') {
122 			netaddr[idx++] = num;
123 			num = 0;
124 		} else {
125 			/*
126 			 * We must have hit a whitespace. Stop
127 			 * parsing now.
128 			 */
129 			netaddr[idx++] = num;
130 			break;
131 		}
132 	}
133 	*maclen = idx;
134 	return (netaddr);
135 }
136