mac字符串转hwaddr，支持各种格式

#include 
#include 
#include 
#include 
#include 

static int str_to_hwaddr(uint8_t *hwaddr, const char *str)
{
	char c;
	uint8_t used = 0;
	uint8_t quarter = 0;
	memset(hwaddr, 0, ETH_ALEN);
	while(isspace(*str)) ++str;
	while('\0' != *str) {
		c = *str++;
		switch(c) {
			default :
				if(strchr("-:. ", c)) {
					if(used) {
						++hwaddr;
						used = 0;
					}
					continue;
				}
				return -1;
			case '0' ... '9':
				quarter = c - '0';
				break;
			case 'a' ... 'f':
				quarter = c - 'a' + 10;
				break;
			case 'A' ... 'F':
				quarter = c - 'A' + 10;
				break;
		}
		*hwaddr = ((*hwaddr)<<4) + quarter;
		if(used) ++hwaddr;
		used = !used;
	}
	return 0;
}

static int print_hwaddr(const char *mac)
{
	uint8_t hwaddr[ETH_ALEN];
	str_to_hwaddr(hwaddr, mac);
	fprintf(stdout, "mac: %s, hwaddr: %02X:%02X:%02X:%02X:%02X:%02X\n",
	                 mac,
	                 (uint32_t)hwaddr[0], (uint32_t)hwaddr[1],
	                 (uint32_t)hwaddr[2], (uint32_t)hwaddr[3],
	                 (uint32_t)hwaddr[4], (uint32_t)hwaddr[5]);
	return 0;
}

int main(int argc, char *argv[])
{
	char mac[128];
	strcpy(mac, "0.1-0:203040506");
	print_hwaddr(mac);
	strcpy(mac, "010...20304050*67");
	print_hwaddr(mac);
	strcpy(mac, "a");
	print_hwaddr(mac);
	strcpy(mac, "0123456789aBcDeF");
	print_hwaddr(mac);
	strcpy(mac, "010203040506");
	print_hwaddr(mac);
	return 0;
}