- char *h_addr_copy = NULL;
-
-#if HAVE_GETADDRINFO
- {
- struct addrinfo hint = { 0 };
- struct addrinfo *res = NULL;
- hint.ai_flags = AI_CANONNAME;
- if (getaddrinfo (host, NULL, &hint, &res) == 0)
- {
- h_addr_copy = strdup (res->ai_canonname);
- freeaddrinfo (res);
- }
- }
-#elif HAVE_GETHOSTBYNAME
- {
- struct hostent *he = gethostbyname (host);
-
- if (he)
- {
-# ifdef HAVE_GETHOSTBYADDR
- char *addr = NULL;
-
- /* Try and get an ascii version of the numeric host address. */
- switch (he->h_addrtype)
- {
-# ifdef HAVE_INET_NTOA
- case AF_INET:
- addr = inet_ntoa (*(struct in_addr *) he->h_addr);
- break;
-# endif /* HAVE_INET_NTOA */
- }
-
- if (addr && strcmp (he->h_name, addr) == 0)
- {
- /* gethostbyname has returned a string representation of the IP
- address, for example, "127.0.0.1". So now, look up the host
- name via the address. Although it may seem reasonable to look
- up the host name via the address, we must not pass `he->h_addr'
- directly to gethostbyaddr because on some systems he->h_addr
- is located in a static library buffer that is reused in the
- gethostbyaddr call. Make a copy and use that instead. */
- h_addr_copy = (char *) malloc (he->h_length);
- if (h_addr_copy == NULL)
- he = NULL;
- else
- {
- memcpy (h_addr_copy, he->h_addr, he->h_length);
- he = gethostbyaddr (h_addr_copy, he->h_length, he->h_addrtype);
- free (h_addr_copy);
- }
- }
-# endif /* HAVE_GETHOSTBYADDR */
-
- if (he)
- h_addr_copy = strdup (he->h_name);
- }
- }
-#endif /* HAVE_GETHOSTBYNAME */
-
- return h_addr_copy;