1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  * 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  *  * Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *  * Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <sys/types.h>
32 #include <net/if_ether.h>
33 #include <ctype.h>
34 
35 static inline int
xdigit(char c)36 xdigit (char c) {
37     unsigned d;
38     d = (unsigned)(c-'0');
39     if (d < 10) return (int)d;
40     d = (unsigned)(c-'a');
41     if (d < 6) return (int)(10+d);
42     d = (unsigned)(c-'A');
43     if (d < 6) return (int)(10+d);
44     return -1;
45 }
46 
47 /*
48  * Convert Ethernet address in the standard hex-digits-and-colons to binary
49  * representation.
50  * Re-entrant version (GNU extensions)
51  */
52 struct ether_addr *
ether_aton_r(const char * asc,struct ether_addr * addr)53 ether_aton_r (const char *asc, struct ether_addr * addr)
54 {
55     int i, val0, val1;
56     for (i = 0; i < ETHER_ADDR_LEN; ++i) {
57         val0 = xdigit(*asc);
58         asc++;
59         if (val0 < 0)
60             return NULL;
61 
62         val1 = xdigit(*asc);
63         asc++;
64         if (val1 < 0)
65             return NULL;
66 
67         addr->ether_addr_octet[i] = (u_int8_t)((val0 << 4) + val1);
68 
69         if (i < ETHER_ADDR_LEN - 1) {
70             if (*asc != ':')
71                 return NULL;
72             asc++;
73         }
74     }
75     if (*asc != '\0')
76         return NULL;
77     return addr;
78 }
79 
80 /*
81  * Convert Ethernet address in the standard hex-digits-and-colons to binary
82  * representation.
83  */
84 struct ether_addr *
ether_aton(const char * asc)85 ether_aton (const char *asc)
86 {
87     static struct ether_addr addr;
88     return ether_aton_r(asc, &addr);
89 }
90