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oliver@schinagl.nlc25f01a2016-11-25 16:30:32 +01001/*
2 * (C) Copyright 2016
3 * Olliver Schinagl <oliver@schinagl.nl>
4 *
5 * SPDX-License-Identifier: GPL-2.0+
6 */
7
8#include <ctype.h>
Masahiro Yamadad2bf1152018-01-21 19:19:15 +09009#include <stdbool.h>
oliver@schinagl.nlc25f01a2016-11-25 16:30:32 +010010#include <stdint.h>
11#include <stdio.h>
12#include <stdlib.h>
13#include <string.h>
14#include <u-boot/crc.h>
15
16#define ARP_HLEN 6 /* Length of hardware address */
17#define ARP_HLEN_ASCII (ARP_HLEN * 2) + (ARP_HLEN - 1) /* with separators */
18#define ARP_HLEN_LAZY (ARP_HLEN * 2) /* separatorless hardware address length */
19
20uint8_t nibble_to_hex(const char *nibble, bool lo)
21{
22 return (strtol(nibble, NULL, 16) << (lo ? 0 : 4)) & (lo ? 0x0f : 0xf0);
23}
24
25int process_mac(const char *mac_address)
26{
27 uint8_t ethaddr[ARP_HLEN + 1] = { 0x00 };
28 uint_fast8_t i = 0;
29
30 while (*mac_address != '\0') {
31 char nibble[2] = { 0x00, '\n' }; /* for strtol */
32
33 nibble[0] = *mac_address++;
34 if (isxdigit(nibble[0])) {
35 if (isupper(nibble[0]))
36 nibble[0] = tolower(nibble[0]);
37 ethaddr[i >> 1] |= nibble_to_hex(nibble, (i % 2) != 0);
38 i++;
39 }
40 }
41
42 for (i = 0; i < ARP_HLEN; i++)
43 printf("%.2x", ethaddr[i]);
44 printf("%.2x\n", crc8(0, ethaddr, ARP_HLEN));
45
46 return 0;
47}
48
49void print_usage(char *cmdname)
50{
51 printf("Usage: %s <mac_address>\n", cmdname);
52 puts("<mac_address> may be with or without separators.");
53 puts("Valid seperators are ':' and '-'.");
54 puts("<mac_address> digits are in base 16.\n");
55}
56
57int main(int argc, char *argv[])
58{
59 if (argc < 2) {
60 print_usage(argv[0]);
61 return 1;
62 }
63
64 if (!((strlen(argv[1]) == ARP_HLEN_ASCII) || (strlen(argv[1]) == ARP_HLEN_LAZY))) {
65 puts("The MAC address is not valid.\n");
66 print_usage(argv[0]);
67 return 1;
68 }
69
70 if (process_mac(argv[1])) {
71 puts("Failed to calculate the MAC's checksum.");
72 return 1;
73 }
74
75 return 0;
76}