Architecture advice,RAW_READ_* encoding

[Amin Azez]

Experts *please* weigh-in:

I'm just writing compression & cache content negotiation between two
samba proxy servers to be separated by a low bandwidth high latency
link. (cue violins).

I need to pass some extra arguments for read requests and responses.

As they will only be used when talking to another Samba I'm strongly
tempted to make use of some of the SMBSRV_VWV_RESERVED reserved words
and slightly touch the pack/unpack functions in reply.c or rawreadwrite.c

It's either that, or invent a RAW_READ_MAGIC operation that mostly
mimics RAW_READ_READX except with the addition of a couple of extra
words but that have to invade nearly every module that cares about
RAW_READ_* so that it can also cope with RAW_READ_MAGIC

I'm hoping interested parties will speak up to help avoid lots of
re-work to make my patches fit for integration.

Uses of the extra words are to:
1. signify that the response is compressed in some way
2. client to provide a hash of cache data so the server can just approve
use of this data instead of returning it.
etc

So, should I steal reserved words, or invent my own operations?

Sam