HttpURLConnection with IPv6 link-local address

[Chris Hegarty]

Hi Bruno,

Wow, I've been working in this area for more than a decade, and this is 
the first bug I've seen on the HttpURLConnection when using URL's with 
literal IPv6 addresses.

That said, I think your points are valid. I created the following bug to 
track this issue:
   https://bugs.openjdk.java.net/browse/JDK-8027308

We just past ZBB [1] for JDK8, so I'm not sure that a fix for this issue 
will make JDK8 FCS, but I would suspect that the changes would be 
suitable for an Update release, 7uXX or 8uXX for example.

-Chris.

[1] http://openjdk.java.net/projects/jdk8/milestones#Zero_Bug_Bounce

On 25/10/2013 02:38, Bruno Harbulot wrote:
> Hello,
>
> I've been trying to use HttpURLConnection to connect to a web server
> using its IPv6 link-local address.
>
> There are two issues with this:
>
> - HttpURLConnection work with URLs with the official % syntax (only the
> informal one) for the scope ID (normally required for link-local addresses).
>
>    Indeed, http://[fe80::a00:27ff:aaaa:aaaa%eth0]/ (for example) can be
> used to send a request, but http://[fe80::a00:27ff:aaaa:aaaa%25eth0]/
> will not send a request at all ("java.net.SocketException: Network is
> unreachable...").
>    The difference is in the encoding of % (which separates the actual IP
> address from the scope ID).
>    RFC 6874 (Section 2) says, "According to URI syntax [RFC3986], "%" is
> always treated as an escape character in a URI, so, according to the
> established URI syntax [RFC3986] any occurrences of literal "%" symbols
> in a URI MUST be percent-encoded and represented in the form "%25"."
>
> - HttpURLConnection sends the scope ID in the Host header, i.e. "Host:
> [fe80::a00:27ff:aaaa:aaaa%eth0]" instead of "Host:
> [fe80::a00:27ff:aaaa:aaaa]".
>
>    Unfortunately, this doesn't seem to be allowed by RFC 4007, and this
> causes Apache Httpd to return a 400 error status.
>    (There are more details in this Apache Httpd issue:
> https://issues.apache.org/bugzilla/show_bug.cgi?id=35122#c4 )
>
>    The only workaround I've found was to set the Host header manually,
> but this also requires enabling "sun.net.http.allowRestrictedHeaders".
>
>
> These problems are present in the latest Java 7 release and in the Java
> 8 early release.
>
> I'm not sure if this has already been reported or discussed. If not,
> would it be possible to address it in future releases?
>
> Best wishes,
>
> Bruno.