Allow direct download templates from IPv6 host address. (apache#5900)

* Allow templates & ISOs from IPv6 host address.

* fix checkstyle issue

* Allow only direct download templates from IPv6 address

Co-authored-by: gabriel <gabriel@apache.org>

Author: sureshanaparti

server/src/main/java/com/cloud/template/HypervisorTemplateAdapter.java

@@ -216,7 +216,7 @@ public TemplateProfile prepare(GetUploadParamsForIsoCmd cmd) throws ResourceAllo
     public TemplateProfile prepare(RegisterTemplateCmd cmd) throws ResourceAllocationException {
         TemplateProfile profile = super.prepare(cmd);
         String url = profile.getUrl();
-        UriUtils.validateUrl(cmd.getFormat(), url);
+        UriUtils.validateUrl(cmd.getFormat(), url, cmd.isDirectDownload());
         if (cmd.isDirectDownload()) {
             DigestHelper.validateChecksumString(cmd.getChecksum());
             Long templateSize = performDirectDownloadUrlValidation(cmd.getFormat(), url, cmd.getZoneIds());

utils/src/main/java/com/cloud/utils/UriUtils.java

@@ -263,6 +263,10 @@ public static Pair<String, Integer> validateUrl(String url) throws IllegalArgume
     }
 
     public static Pair<String, Integer> validateUrl(String format, String url) throws IllegalArgumentException {
+        return validateUrl(format, url, false);
+    }
+
+    public static Pair<String, Integer> validateUrl(String format, String url, boolean skipIpv6Check) throws IllegalArgumentException {
         try {
             URI uri = new URI(url);
             if ((uri.getScheme() == null) ||
@@ -283,7 +287,7 @@ public static Pair<String, Integer> validateUrl(String format, String url) throw
                 if (hostAddr.isAnyLocalAddress() || hostAddr.isLinkLocalAddress() || hostAddr.isLoopbackAddress() || hostAddr.isMulticastAddress()) {
                     throw new IllegalArgumentException("Illegal host specified in url");
                 }
-                if (hostAddr instanceof Inet6Address) {
+                if (!skipIpv6Check && hostAddr instanceof Inet6Address) {
                     throw new IllegalArgumentException("IPV6 addresses not supported (" + hostAddr.getHostAddress() + ")");
                 }
             } catch (UnknownHostException uhe) {