rem: if ((host = gethostbyaddr((char *) addr, sizeof(struct in_addr), AF_INET6)) != NULL)
add: if ((host = getipnodebyaddr((char *) addr, sizeof(struct in6_addr), AF_INET6, NULL)) != NULL)
context: addr_to_host(const struct in6_addr *addr){	struct hostent *host;	/* TODO: gets errno 96 (EPFNOSUPPORT) on Debian/Sid. Got only AF_INET! */	if ((host = gethostbyaddr((char *) addr,				  sizeof(struct in_addr), AF_INET6)) != NULL)		return (char *) host->h_name;	return (char *) NULL;}