Xref: utzoo comp.mail.sendmail:276 comp.bugs.4bsd:1106
Path: utzoo!attcan!uunet!mcvax!nikhefh!e07
From: e07@nikhefh.hep.nl (Eric Wassenaar)
Newsgroups: comp.mail.sendmail,comp.bugs.4bsd
Subject: sendmail queue run interferes with active transactions
Message-ID: <580@nikhefh.hep.nl>
Date: 22 Nov 88 23:18:04 GMT
Organization: Nikhef-H, Amsterdam (the Netherlands).
Lines: 29


A sendmail queue run may destructively interfere with other active
sendmail transactions. As a result, mail may be lost, left-over queue
files may remain in the mqueue directory, and various error messages
may appear in the syslog file.

Analysis:
The routine runqueue() in queue.c scans the queue, calling dowork()
for each individual entry. If an entry is found busy, dowork() will
syslog such entry as "AAxxxxx: locked", and return immediately.
After the queue scan, runqueue() calls finis() to terminate.
However, if the last queue entry examined by dowork() was locked,
'CurEnv->e_id' still contains the id of this entry, and dropenvelope()
which is called by finis() will inappropriately perform cleanup action
for this queue entry, possibly unlinking associated queue files.

Remedy:
Either make CurEnv->e_id = NULL again in dowork() when returning after
signaling a locked entry, or put CurEnv->e_id = NULL in runqueue()
just before calling finis(). Now dropenvelope() will exit immediately.
Note that in case dowork() could process a non-active entry, it will
internally call dropenvelope() for this entry.

Eric Wassenaar
-- 
Organization: NIKHEF-H, National Institute for Nuclear and High-Energy Physics
Address: Kruislaan 409, P.O. Box 41882, 1009 DB Amsterdam, the Netherlands
Phone: +31 20 5920412   Home phone: +31 20 909449    Telex: 10262 (hef nl)
Internet: e07@nikhefh.hep.nl  Bitnet: nikhefh!e07@mcvax.bitnet