+ WARNINGS
+ HOST must be a string representation of a resolvable name for this host.
+ Strings containing an IP address in dotted decimal notation will be
+ returned as-is, without further resolution.
+
+ The use of the word "canonical" in this context is unfortunate but
+ entrenched. The value returned by this function will be the end result
+ of the resolution of any CNAME chains in the DNS. There may only be one
+ such value for any given hostname, though the actual IP address
+ referenced by this value and the device using that IP address may each
+ actually have any number of such "canonical" hostnames. See the POSIX
+ getaddrinfo spec <http://www.opengroup.org/susv3xsh/getaddrinfo.html">,
+ RFC 1034 <http://www.faqs.org/rfcs/rfc1034.html>, & RFC 2181
+ <http://www.faqs.org/rfcs/rfc2181.html> for more on what this confusing
+ term really refers to. */
+char *
+canon_host_r (char const *host, int *cherror)
+{
+ char *retval = NULL;
+ static struct addrinfo hints;
+ struct addrinfo *res = NULL;
+ int status;
+
+ hints.ai_flags = AI_CANONNAME;
+ status = getaddrinfo (host, NULL, &hints, &res);
+ if (!status)