validate_hostname: remove DNS hostname lookups

Instead of the server passing in the client IP address and having
validate_hostname() resolve it, resolve the name in new_connection()
and pass it to validate_hostname().  This significantly simplifies
the certificate validation callback.

Author: millert

include/hostcheck.h

@@ -30,7 +30,7 @@ typedef enum {
 } HostnameValidationResult;
 
 HostnameValidationResult validate_hostname(const X509 *cert,
-	const char *hostname, const char *ipaddr, int resolve);
+	const char *hostname, const char *ipaddr);
 
 #endif /* HAVE_OPENSSL */