1 // SPDX-License-Identifier: GPL-2.0+
4 * Olliver Schinagl <oliver@schinagl.nl>
13 #include <u-boot/crc.h>
15 #define ARP_HLEN 6 /* Length of hardware address */
16 #define ARP_HLEN_ASCII (ARP_HLEN * 2) + (ARP_HLEN - 1) /* with separators */
17 #define ARP_HLEN_LAZY (ARP_HLEN * 2) /* separatorless hardware address length */
19 uint8_t nibble_to_hex(const char *nibble
, bool lo
)
21 return (strtol(nibble
, NULL
, 16) << (lo
? 0 : 4)) & (lo
? 0x0f : 0xf0);
24 int process_mac(const char *mac_address
)
26 uint8_t ethaddr
[ARP_HLEN
+ 1] = { 0x00 };
29 while (*mac_address
!= '\0') {
30 char nibble
[2] = { 0x00, '\n' }; /* for strtol */
32 nibble
[0] = *mac_address
++;
33 if (isxdigit(nibble
[0])) {
34 if (isupper(nibble
[0]))
35 nibble
[0] = tolower(nibble
[0]);
36 ethaddr
[i
>> 1] |= nibble_to_hex(nibble
, (i
% 2) != 0);
41 for (i
= 0; i
< ARP_HLEN
; i
++)
42 printf("%.2x", ethaddr
[i
]);
43 printf("%.2x\n", crc8(0, ethaddr
, ARP_HLEN
));
48 void print_usage(char *cmdname
)
50 printf("Usage: %s <mac_address>\n", cmdname
);
51 puts("<mac_address> may be with or without separators.");
52 puts("Valid seperators are ':' and '-'.");
53 puts("<mac_address> digits are in base 16.\n");
56 int main(int argc
, char *argv
[])
63 if (!((strlen(argv
[1]) == ARP_HLEN_ASCII
) || (strlen(argv
[1]) == ARP_HLEN_LAZY
))) {
64 puts("The MAC address is not valid.\n");
69 if (process_mac(argv
[1])) {
70 puts("Failed to calculate the MAC's checksum.");