Subject: Zmailer to Exchange bug ?

From: Mark Visser <[email-masked]>
Date: Sun, 19 May 2002 23:33:17 +0200 (CEST)

Hm,

Lately we noticed on our boxes that we got hanging smtpservers.
The version we're running right now is: ZMailer Server 2.99.55

What seems to happen is that after getting to BDAT state the connections
hang and Zmailer nor the remote end closes them, causing smtpserver to
just say sleep, sleep sleep (according to strace)

The boxes to which we see hanging smtpservers all have similar versions:

Microsoft ESMTP MAIL Service, Version: 5.0.2195.4453 ready at..
Microsoft ESMTP MAIL Service, Version: 5.0.2195.4905 ready at..
Microsoft ESMTP MAIL Service, Version: 5.0.2195.2966 ready at..

A sample one from ps says:

daemon    1411  0.0  0.3 1960 1504 ?        S   May 13  0:00
<tacv-internet.tacv.com BDAT 129671 LAST net.tacv.com BDAT 129671 LAST
.tacv.com BDAT 129671 LAST .com BDAT 129671 LAST m BDAT 129671 LAST

# truss -p 1411
    *** SUID: ruid/euid/suid = 0 / 1 / 1  ***
read(0, 0xEFFFD310, 8192)       (sleeping...)

and that's all there is.

Did people see this before ? I tried 2.99.56 snapshot some time ago, but
that kept mail instead of sending it on (i didn't see quickly why, so i
backed it out).

This happens on both ETRN as fallback MX boxes.

Any hints appreciated.

Mark

-
To unsubscribe from this list: send the line "unsubscribe zmailer" in
the body of a message to [email-masked]

---

From: Arnt Gulbrandsen <[email-masked]>
Date: Mon, 20 May 2002 12:02:00 +0200

This raises a question: Should zmailer continue to support BDAT?

I think it's clear that the extension has failed. A little software
supports it, not much, and support doesn't seem to be growing. It's not
much used, it doesn't offer much of an advantage, and it can have bugs:
Looks like it may not be worth its price.

Mark: change the value DO_CHUNKING to 0 in transports/smtp/smtp.h. That
should disable BDAT support and everything should then work.

--Arnt
-

---

From: Matti Aarnio <[email-masked]>
Date: Mon, 20 May 2002 13:29:50 +0300

> read(0, 0xEFFFD310, 8192)       (sleeping...)

   I have been rather confused with this report, and apparently Arnt
   was too, as he referred to the outgoing smtp TA feature disabling..

   For incoming  smtpserver's feature control you can use PARAM
   statements at   $MAILSHARE/smtpserver.conf  file.  Specifically

       PARAM NoCHUNKING

   to disable BDAT support in reception.

> that kept mail instead of sending it on (i didn't see quickly why, so i

   Some people have asked me to make a release ASAP..  Yes, I should.
   It has been about a year since previous one, and I have been hacking
   in the CVS since then (not having very much time, though..)

   11 months ago (after 55-patch1) I addressed some of timeout problem
   issues at the  smtpserver,  and now it looks like I am not seeing
   any stuck servers.  (That might solve the thing you see.)

   I am running the lattest code at several machines, and the only
   excuse for not making a release is that I see some mighty strange
   protocol errors from various places in general direction of eastern
   Asia/China..  As if the smtp TA client code is somehow broken, and
   is sending inappropriately formatted data out -- e.g. in places
   where there should be  CRLF,  it is (claimed to be) sending an LF
   alone..

-- 
/Matti Aarnio	<[email-masked]>
-
To unsubscribe from this list: send the line "unsubscribe zmailer" in
the body of a message to [email-masked]

---

From: Arnt Gulbrandsen <[email-masked]>
Date: Mon, 20 May 2002 12:37:51 +0200

Matti Aarnio <[email-masked]>
>    was too, as he referred to the outgoing smtp TA feature disabling..

The sound you hear is me hitting my head ;) I saw the SMTP banners saying
Microsoftesque things and assumed ZMailer was the client.

However, even if zmailer is the server, my doubts about BDAT's usefulness
remain valid.

--Arnt
-

---

From: Mark Visser <[email-masked]>
Date: Mon, 20 May 2002 18:31:42 +0200 (CEST)

>    was too, as he referred to the outgoing smtp TA feature disabling..

My apogolies for the confusion, *note to self: first read over what you
typed, even if it's late*

As was hopefully clear a little later on, we're not talking about
smptserver, but about smtp process, the sending out from queue to remote.

>    to disable BDAT support in reception.

I'll give that a try yes. It's 4 boxes, 2 of each kind doing it, so
testing with one of them should easily show diffs. They are identical for
the rest.

>    any stuck servers.  (That might solve the thing you see.)

Ok, i grabbed the CVS copy of today and compiled it.
Few warnings but compiles with less warnings then the previous one. If you
want to have the output of configure & make (SunOS 5.6 SPARC) send me a
mail and i'll pass it on, but  if i remember well you had 2.6 boxes
yourself.

>    where there should be  CRLF,  it is (claimed to be) sending an LF

When i tried 2.99.56-pre1 snapshot from CVS in january i noticed on our
etrn boxes that it kept all mail, as if it took 'queueonly' very literal.
(note..this is with the box getting ETRN requests).

I'll give the new CVS copy a try.

> > This happens on both ETRN as fallback MX boxes.

Thanx Arnt & Matti !

Mark

-

---

From: Mark Visser <[email-masked]>
Date: Mon, 20 May 2002 18:33:55 +0200 (CEST)

> However, even if zmailer is the server, my doubts about BDAT's usefulness

Sorry for the confusion Arnt, see the other mail. It's Zmailer as server
and the Exchange box (customers, so no way you could get that changed
probably (;) as receiving end.

Hence.. read smtp instead of smtpserver please. Nevertheless it's still
BDAT at stake, and i'll certainly try the disabling of it, but as we have
offered it so long and the old release 2.99.51 didn't had hanging smtp's i
didn't directly thought of disabling it.

Mark

-

---

From: Arnt Gulbrandsen <[email-masked]>
Date: Mon, 20 May 2002 18:55:13 +0200

Mark Visser <[email-masked]>
> didn't directly thought of disabling it.

Well, it might have been broken when LMTP or (less likely) TLS support was
introduced in the code. I don't know whether either of those were added
after 2.99.51, though.

You can offer it in your smtpserver even though your smtp won't use it
when offered.

--Arnt
-

---

From: Mark Visser <[email-masked]>
Date: Mon, 20 May 2002 19:13:45 +0200 (CEST)

> You can offer it in your smtpserver even though your smtp won't use it

As Matti and you were confused by smtpserver vs. smtp  by my mail, a
collegae reminded me we get hanging smtpservers also regularly and
sometimes smtp (*deep deep sigh, confusion all over).

To get it straight once and for all.

>From a ETRN box that was fully restarted on 13 may we have now:

ps -ef | grep smtpserver | awk '{print $5" "$6}' | sort | uniq -c
  22 May 13
 112 May 14
  41 May 15
  23 May 16
  38 May 17
  26 May 18
   8 May 19

the ta/smtp's on this box are all recent (last x hours)

Zmailer 2.99.55
Kids: 33  Idle:  6  Msgs: -311225  Thrds: 1263  Rcpnts: 13361  Uptime:
12d2h

As for these hanging ones, they are BDAT sessions sending TO us, from
those Exchange boxes mentioned earlier. So, one of the 2 sides doesn't
close it.

I've disabled CHUNKING now on one box, will see what happens.

Mark

--
Warning: You can get rid of all the bugs by disabling them from the main menu.

-