C语言字符串效验是IPV4还是IPV6

example： str_ip_mask = "192.168.1.1/24";
int ip_mask_parse(char * str_ip_mask)
{
	char *pos = str_ip_mask;
	char str_ip[44] = {0};
	unsigned int str_ip_len = 0;
	char str_mask[8] = {0};
	unsigned int str_mask_len = 0;
	struct in_addr ipv4_addr;
	struct in6_addr v6_addr;
	int mask = 0;
	int is_ipv6 = 0;
	int mask_start= 0;

	while('' != *pos)
	{
		switch(*pos)
		{
			case '/'
				mask_start = 1;
				break;
			case ':'
				is_ipv6 = 1;
				break;
			default:
				if(!mask_start)
				{
					str_ip[str_ip_len++] = *pos;
				}
				else
				{
					str_mask[str_mask_len++] = *pos;
				}
				break;
		}
		pos++;
	}
	if(0 == str_ip_len || 0 == str_mask_len)
	{
		return -1;
	}
	
	if(is_ipv6)
	{
		if(1 != inet_pton(AF_INET6, str_ip, &v6_addr))
		{
			return -1;
		}
	}
	else
	{
		if(1 != inet_pton(AF_INET, str_ip, &ipv4_addr))
		{
			return -1;
		}
	}
	mask = strtoul(str_mask, 0, 0);
	
	return 0;
}