IPV4_STR_SZ
char addr_str[IPV4_STR_SZ] = {};
strncpy(addr_str, inet_ntoa(addr), IPV4_STR_SZ - 1);
char to_str[IPV4_STR_SZ] = {}, from_str[IPV4_STR_SZ] = {};
strncpy(to_str, inet_ntoa(*(struct in_addr *)&to), IPV4_STR_SZ - 1);
strncpy(from_str, inet_ntoa(from), IPV4_STR_SZ - 1);