Weird pop3d hang problem (fd blocked?!)

[Ken Murchison]

foobar wrote:
> Hi,
> 
> Today our mailserver jammed all its pop3d processes and trace said
> "read(10," and it was blocking there.
> 
> imap-processes were served fine and db-files were ok (DB4).
> 
> Then I restarted all processes and checked db-files and tried to debug.
> 
> Then I was desparate and I restarted whole system and after init
> everything was fine again (pop3 was served without that jam.)
> 
> titus at foo titus ~%> telnet 0 110
> Trying 0.0.0.0...
> Connected to 0.
> * Hanging here (waiting banner) *
> Escape character is '^]'.
> ^]
> telnet> quit
> Connection closed.
> 
> ^ No banner even.
> 
> Imap(s) (working fine, banner prints)
> 
> Escape character is '^]'.
> * OK foo Cyrus IMAP4 v2.1.11 server ready
> 
> Authentication and all operations worked fine on imap's side.
> 
> I just wonder what caused this kind block in pop3-processes or what
> _could_ cause this kind problem..
> 
> Kernel: 2.4.18-14 / GNU Linux
> I am using PAM (via saslauthd) for pop and imap.
> 
> No, I didn't check if I was out of entropy (random).

This is most likely your problem, since the pop3d banner includes a 
random challenge for APOP.


-- 
Kenneth Murchison     Oceana Matrix Ltd.
Software Engineer     21 Princeton Place
716-662-8973 x26      Orchard Park, NY 14127
--PGP Public Key--    http://www.oceana.com/~ken/ksm.pgp