On Fri, 30 May 2003, Oliver Eikemeier wrote:
> Why is the "shadow_transport" option only allowed
> on local transports? The ability to log more detailed
> information is useful for remote deliveries too.
>
> Is there a reason that it is forbidden for remote
> tranports?
Yes. I found it too hard to implement. :-)
Now, can I remember what the problems were? ....
I think the main problem is in mixing transport types. That is, it would
be easier to allow a remote transport to have another remote transport
as a shadow than to allow complete generality. Since I suspect what
people actually want is remote shadowed by local, this wasn't worth
pursuing.
The problem is in the way Exim runs deliveries. First, it does all the
local deliveries, retaining root privilege so that it can change uid as
necessary. Then it uses setuid to give up root privilege for ever, and
changes to the exim user. Then it does the remote deliveries. You see
the problem?
As far as logging more detailed information goes, another approach is
something that is on the wish list, which is a hook into the logging
code.
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.
Get the Exim 4 book: http://www.uit.co.uk/exim-book
