[ On Monday, December 17, 2001 at 22:26:27 (+0000), Chris Thompson wrote: ]
> Subject: Vacation rate-limiting (was: Re: [Exim] Administrivia ...)
>
> Unfortunately, some versions of "vacation" don't do this in a robust
> way. Any problem with the ${HOME}/.vacation dbm file that records
> messages sent, e.g. a failure to create it because the user mucked up,
> or to extend it because the user is over quota, causes the autoreply
> to be sent anyway. This has in fact caused loops for us in the past.
Ah, this is interesting. From my memory I seem to recall that the
original version of 'vacation' (i.e. the one from 4.3BSD or later) will
simply bomb out if the ~/.vacation.db* file(s) are not initialised.
This seems to be borne out by examination of the 4.3-reno code, though
I've not compiled it since to test again.
My version automatically creates the db file if it does not yet exist
(setting the interval to a default of seven days).
> The safe thing would be *not* to send the message if there is trouble
> with the dbm file, of course.
Very good point!
I'll make sure my version fails safely in this way too for any failure.
* TODO:
*
* Make sure any error recording the correspondent address in the db file
* causes an error exit so that no reply is sent if it cannot be recorded.
*
* Also make sure any actual error reading the db file to test a correspondent
* address is detected and will cause an error exit to prevent a reply from
* being sent.
this will leave only cases of malice which can cause loops -- such as
the someone running a frequent cron job that deletes the db file....
I'd rather people risk this kind of malicious abuse than to not have the
auto-create feature.
--
Greg A. Woods
+1 416 218-0098; <gwoods@???>; <g.a.woods@???>; <woods@???>
Planix, Inc. <woods@???>; VE3TCP; Secrets of the Weird <woods@???>
