OpenLDAP behavior with regards to MessageID and the RFC

[Michael Torrie <torriem@chem.byu.edu>]

I'm writing a special-purpose LDAP proxy server that has the ability to
modify ldap messages it receives (raw wire protocol here) from a client
before passing it to the server (in my case OpenLDAP 2.0 and 2.1).  In
order to stay correct I have read the RFCs on LDAPv3 wire protocol so as
not to break anything.  I have a question on how OpenLDAP implements the
MessageID aspect of the RFC.  

The RFC 2251 states simply that the MessageID cannot be reused over the
course of a connection; each request must have a different MessageID
than any outstanding request; and that typically the MessageID is
incremented [by one].

Now my questions.  OpenLDAP (server and client libraries start at 1 and
simply increment it for every request.  As I read the RFC, the client
could increment, decrement or make random the MessageID so long as the
above-mentioned rules are followed and everything should work fine.  In
my testing of my proxy server, in one instance I accidentally
incremented the MessageID such that it was more than 1 greater than the
previous MessageID that the request the server had last received and
OpenLDAP 2.0 never responded to it.  Is this a bug in OpenLDAP?  (It's
been a long time since I tried this -- it was a bug in my program that
has been corrected).

At any rate, my proxy server currently only functions if the MessageID
is incremented by the client for each request by one, which could be a
problem as I read the RFCs.  In practice does any client ever choose
MessageIDs other than how the OpenLDAP client libraries do? 
Furthermore, in practice (besides the abort request) are there ever
multiple requests in progress and does OpenLDAP handle that?  All of the
LDAP transactions I've ever sniffed seemed to be strictly request and
response.

Michael

-- 
Michael Torrie <torriem@chem.byu.edu>