On Fri, 2005-02-25 at 17:09, Russell Stuart wrote:
> Version of Exim: 4.43, + Exiscan patch
> Operating System: Debian Sarge
> URL will full details: http://www.lubemobile.com.au/ras/exim
>
> I am getting duplicated messages with Exim. The about URL has all
> the details, like logs, cron scripts, -H files, and config files.
I didn't get far looking at the code. I soon as commenced the
problem appeared to go away - I could not reproduce it, even
by sending the original messages that caused the problem. To
I have spent the last 5 hours or so trying to reproduce it.
The conditions trigger the bug are:
1. A new address is added with a redirect router with the unseen
directive.
2. There is a retry record pending for new address.
3. The new address is moved to the front of deliver.c's delivery
queue by another re-direct router.
4. A "control = queue_only" is in effect (perhaps - not sure about
this one).
5. The original address can be successfully delivered to.
If all these conditions are met, then each time a queue running
comes along, it will create a duplicate email to original
address. This will happen until the retry record expires.
Here is a shell script that demonstrates the bug, by re-creating
these conditions. A copy is on the web site, file name "bug.sh".
It does not do any real deliveries.
#!/bin/bash
#
# To run this script:
#
# a. Stop all Exim queue runners, and prevent any new ones from
# starting.
#
# b. Create a new, empty directory. Ensure the directory is
# world readable, searchable and writable. Ensure its parents
# are all world readable and searchable.
#
# c. cd to the new directory. Copy this script into it.
#
# d. Run the script as root.
#
# What it does:
#
# This script demonstrates a bug in exim. Under these conditions:
#
# 1. A new address is added with a redirect router with the
# unseen directive.
# 2. There is a retry record pending for new address.
# 3. The new address is moved to the front of deliver.c's
# delivery queue by another re-direct router.
# 4. "control = queue_only" is in effect (perhaps - not sure
# about this one).
# 5. The original address can be successfully delivered to.
#
# Every new queue runner will generate a duplicate email to
# the original address until the defer expires.
#
# The script doesn't do any real deliveries. Instead, the
# delivery is handled by the the lmtp emulation below, which
# just records all successful delivery attempts.
#
# Outputs:
#
# - A list of deliveries made by exim is printed on stdout.
# If exim worked there should only be one to each address.
# - A number of exim -d+all logs are created in the current
# directory.
# - The configuration file used is left in the current
# directory.
#
#
# Implement the LMTP protocol for Exim. This is used by
# bug-exim.conf below.
#
# If the mail contains a line starting with "421" no delivery
# is simulated. Instead a 421 error is returned to exim.
#
# Every successful delivery done by this transport is logged
# to bug-lmtp-deliveries.log.
#
if [[ x"$1" = x"--lmtp" ]]
then
dir=$(dirname $0)
echo 220 Hi!
while :
do
while read line
do
case "$line" in D*) break;; esac
case "$line" in Q*) echo "221 2.0.0 Goodbye Exim!"; exit;; esac
case "$line" in R*) rcpt=${line#*:}; rcpts="$rcpts ${rcpt%?}";; esac
echo "220 Thank you Exim!"
done
echo "354 Go Exim!"
reply=
while :
do
case "$line" in 421*) reply="421 Error!";; esac
case "$line" in .*) break;; esac
read line
done
if [[ -n "$reply" ]]
then
echo $reply
exit
else
d=
for f in $rcpts
do
[[ -z "$d" ]] || echo "250 2.0.0 $d OK" | tee --append $dir/bug-lmtp-deliveries.log
d=$f
done
echo "250 2.0.0 $d OK" | tee --append $dir/bug-lmtp-deliveries.log
fi
done
fi
[[ $(id -u) = 0 ]] || {
echo 1>&2 "$0: I must be run as root!"
exit 1
}
if ps -ef | egrep -w '[e]xim|[e]xim4'
then
echo 1>&2 "$0: Please stop exim and all queue runners!"
exit 1
fi
#
# We must be in the local directory.
#
[[ -s bug.sh ]] || {
echo 1>&2 "$0: I must be run as ./bug.sh!"
exit 1
}
chmod +x bug.sh
rm -f bug-*.{conf,log}
>bug-lmtp-deliveries.log
chmod a+rw bug-lmtp-deliveries.log
#
# Build the exim.conf
#
cat >bug-exim.conf \
<<======================================
acl_not_smtp = not_smtp
begin acl
not_smtp:
accept control = queue_only
begin routers
duplicate:
driver = redirect
local_parts = x
data =
z@www.exim.org
unseen
rename_z:
driver = redirect
local_parts = z
data =
y@www.exim.org
lmtp:
driver = accept
transport = lmtp
begin transports
lmtp:
driver = lmtp
batch_max = 1000
command = $PWD/bug.sh --lmtp
retry_use_local_part = true
begin retry
* * F,1d,1h
======================================
#
# First we must generate a retry record for
#
y@www.exim.org.
#
( echo "To:
y@www.exim.org"
echo
echo "421"
) | exim4 -C $PWD/bug-exim.conf -t -d+all >bug-delivery-y.log 2>&1
exim4 -C $PWD/bug-exim.conf -q # A queue runner to the retry record
exim4 -Mrm $(exipick -r '.@www\.exim\.org' -i) # Don't need that message any more
#
# Now create the message that causes the problem.
#
( echo "To:
x@www.exim.org"
echo
echo "Test"
) | exim4 -C $PWD/bug-exim.conf -t -d+all >bug-delivery-x.log 2>&1
exim4 -C $PWD/bug-exim.conf -q -d+all >bug-delivery-1.log 2>&1
exim4 -C $PWD/bug-exim.conf -q -d+all >bug-delivery-2.log 2>&1
exim4 -C $PWD/bug-exim.conf -q -d+all >bug-delivery-3.log 2>&1
exim4 -Mrm $(exipick -r '.@www\.exim\.org' -i) # Don't need that message any more
#
# Print the results.
#
echo "Deliveries done by lmtp transport:"
cat bug-lmtp-deliveries.log
