[Click] Alignment info for custom element

[Cliff Frey]

Well, you could make it so that click-align knew that there were no
alignment guarantees after your element (assuming that your element actually
does not provide any alignment guarantees)

I think that you would do this by adding a clause in click-align.cc with
your element and
GeneratorAligner(Alignment(1, 0))
as the type of alignment that your element provided.

However, some elements that pull an arbitrary number of bytes (like
StripToNetworkHeader) can likely be given a GeneratorAligner of (4, 0),
because the network header is (almost) always 4 byte aligned.

Cliff

On Tue, Nov 9, 2010 at 10:56 AM, Roberto Riggio <
roberto.riggio at create-net.org> wrote:

> Hi,
>
> which is the right approach (if any) to handle the alignment info (in
> the click_align tool)
> for an element which pulls a variable number of bytes from a packet. The
> amount of bytes
> is contained in the header itself.
>
> I was thinking about putting a classifier element before the custom
> element (and then handle
> the alignment for each case), but this solution does not look very elegant.
>
> Any idea
> R.
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