Trace logging project

[Greg Hudson]

On Fri, 2009-09-04 at 17:17 -0400, ghudson at MIT.EDU wrote:
> Based on recent feedback from krb5 users, I've written up an early
> project page on trace logging:

It sounds like no one has strong opinions about this, which is fine;
it's not going to be very intricate.

I'm going to start with a simple binary switch: you turn on tracing (by
specifying a filename in KRB5_TRACE) and you get everything.  If there
turns out to be a need for pre-filtering, that can be added later,
although it will of course mean marking up all of the existing trace
calls.

Trace calls will require a context.  I don't think there's any important
code to trace with no access to a context, and it makes it simple to
avoid tracing for secure contexts.

When I went to add my first tracing call, I realized that we'll need a
custom formatter to deal with principal names and krb5_data structures
and the like.  Fortunately, there already is one in
lib/krb5/os/sendto_kdc.c, which was easy to adapt.

I've adjusted the project page and kicked into review status, with an
end date of September 18th (one week).  I have the plumbing written now,
and can commence the work of littering the code base with tracing calls.