[syslinux] Opinion wanted: metadata in HTTP requests

[H. Peter Anvin]

I'm thinking it might be an interesting idea to pass ipappend-style
metadata (and quite possibly additional information, e.g. obtained from
DMI) when making a http request, but I'm not 100% sure about the best
way to do it.

Options are pretty much:

1. some kind of metavariables in either the configuration file or in
   the filename syntax.

   + very general.
   - cumbersome for the user.
   - most complex to implement.

2. as a query string automatically appended to the requested URL.

   + easy.
   - makes it impossible to use any other kind of queries.
   - high overhead (data sent on every request.)

3. as a query string appended to the requested URL when requested.

   This probably means using a pseudo-URL namespace, e.g.:

   http+info://...

   + easy.
   - nonstandard syntax.
   - cumbersome.

4. using the http cookie protocol.

   + easy.
   - somewhat high overhead (cumbersome encoding, data sent on every
     request).

5. as a HTTP query sent via PUT or POST.

   This probably means using a pseudo-URL namespace, e.g.:

   http+post://...

   + easy.
   + can be cached server side if only sent once.
   - nonstandard syntax.
   - cumbersome.
   - very high overhead when used; the standard MIME forms encoding is
     very cumbersome.

6. as an HTTP PUT sent on demand.

   This would be an explicit command, say:

   sendconfig http://...

   + only sent once (at least per read of the config file).
   + can be made to work for FTP or even TFTP.
   + can in theory send a fair bit of data.
   + implementation can be shared with other client-side data producers.
   - send *after* the config file, which pretty much means that one
     then need to use a separate CONFIG command to get a customized
     configuration file.
   - cumbersome implementation.

Thoughts?  Other ideas.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.