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/*
* (C) Copyright 2016
* Olliver Schinagl <oliver@schinagl.nl>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <u-boot/crc.h>
#define ARP_HLEN 6 /* Length of hardware address */
#define ARP_HLEN_ASCII (ARP_HLEN * 2) + (ARP_HLEN - 1) /* with separators */
#define ARP_HLEN_LAZY (ARP_HLEN * 2) /* separatorless hardware address length */
uint8_t nibble_to_hex(const char *nibble, bool lo)
{
return (strtol(nibble, NULL, 16) << (lo ? 0 : 4)) & (lo ? 0x0f : 0xf0);
}
int process_mac(const char *mac_address)
{
uint8_t ethaddr[ARP_HLEN + 1] = { 0x00 };
uint_fast8_t i = 0;
while (*mac_address != '\0') {
char nibble[2] = { 0x00, '\n' }; /* for strtol */
nibble[0] = *mac_address++;
if (isxdigit(nibble[0])) {
if (isupper(nibble[0]))
nibble[0] = tolower(nibble[0]);
ethaddr[i >> 1] |= nibble_to_hex(nibble, (i % 2) != 0);
i++;
}
}
for (i = 0; i < ARP_HLEN; i++)
printf("%.2x", ethaddr[i]);
printf("%.2x\n", crc8(0, ethaddr, ARP_HLEN));
return 0;
}
void print_usage(char *cmdname)
{
printf("Usage: %s <mac_address>\n", cmdname);
puts("<mac_address> may be with or without separators.");
puts("Valid seperators are ':' and '-'.");
puts("<mac_address> digits are in base 16.\n");
}
int main(int argc, char *argv[])
{
if (argc < 2) {
print_usage(argv[0]);
return 1;
}
if (!((strlen(argv[1]) == ARP_HLEN_ASCII) || (strlen(argv[1]) == ARP_HLEN_LAZY))) {
puts("The MAC address is not valid.\n");
print_usage(argv[0]);
return 1;
}
if (process_mac(argv[1])) {
puts("Failed to calculate the MAC's checksum.");
return 1;
}
return 0;
}