[horde] Activesync not closing connections

[Simon Brereton]

On 18 March 2013 10:08, Tom Seeley <horde at tomseeley.co.uk> wrote:
> Hi,
>
> I had been using Activesync relatively successfully for several weeks, but
> recently (I'm afraid I'm not sure exactly when), I seem to have sprung some
> sort of leak.
>
> The observed behaviour is that Dovecot locks me out of my account because I
> have exceeded "mail_max_userip_connections", which is set to 10 by default.
> Dovecot isn't lying, what appears to be happening is that my AS client
> (Samsung galaxy s2) is making requests that aren't closing.  Very quickly
> after starting apache I see something like this:
>
> # netstat -an |grep 192.168.0.221
> tcp        0     52 10.0.0.1:22               192.168.0.221:58347
> ESTABLISHED
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:38544
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:35204
> CLOSE_WAIT
> tcp        0      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:58502
> ESTABLISHED
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:55443
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:38506
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:42254
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:42254
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:42254
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:42254
> CLOSE_WAIT
> tcp       24      0 ::ffff:10.0.0.1:443       ::ffff:192.168.0.221:42254
> CLOSE_WAIT
>
> After the above no more logins into horde are possible to my account+IP.
>
> My understanding of TCP would lead me to suggest that the client has
> requested a close of the connection and the server has yet to release the
> socket.
>
> As a workaround I have resorted to changing my phone to a 5 min sync (ie
> turning off push) to maintain functionality.

Funnily enough I've been running into this problem myself.  I put it
down to the fact that I now have two devices that use activeSync on
the same account and so I bumper my mail_max_userip to 20 for now and
that seems to have fixed the issue (but I only did it this morning, so
we will see).  I was prompted to do this because I have increasingly
been told by one device or the other that the sign-in failed (Samsung
Galaxy S3) or the password wasn't correct (iPhone 4s).

I am running git though.  Hardly conclusive proof, but I thought you'd
want to know.

Simon