Re: [exim] no reverse lookup of hostname in log of SMTP conn…

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Autor: Philip Hazel
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A: Calum Mackay
CC: exim-users
Assumpte: Re: [exim] no reverse lookup of hostname in log of SMTP connection open
On Thu, 23 Sep 2004, Calum Mackay wrote:

> Is there any reason why there is no reverse-lookup to get a hostname for
> logging an incoming connection, but there is when logging the connection
> closure?


Yes. The connection logging happens in the daemon process, before it
forks the accepting process. The reason for that is given in this
comment in the code:

/* OK, the connection count checks have been passed. Before we can
fork the accepting process, we must first log the connection if
requested. This logging used to happen in the subprocess, but doing
that means that the value of smtp_accept_count can be out of step by
the time it is logged. So we have to do the logging here and accept
the performance cost. */

Note also that reverse lookups are optional. If you don't set
host_lookup to require them, and you don't have anything else in your
config that uses the host name, no lookup is ever done.


-- 
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