[Dovecot] Vpopmail Dynamic Authentication Module

[Eric Sisolak]

Hello,

We currently use qmail with vpopmail for e-mail and are looking to switch
from courier-imap to dovecot for IMAP on our RedHat EL 5 systems.  Our goal
is to use the dovecot RPM supplied by RH (v1.0.7) if at all possible.  We
can do this if we are able to dynamically load the vpopmail auth module.

The wiki (http://wiki.dovecot.org/CompilingSource) notes that this should
be possible:

Dovecot can also dynamically load authentication modules from the
$prefix/lib/dovecot/auth/ directory. Binary packages builders should use
them for authentication modules which require external libraries (e. g.
LDAP and vpopmail). There is no standard way to build them as modules
currently, but something like this should work:

gcc -shared -fPIC -DHAVE_CONFIG_H -DUSERDB_VPOPMAIL -DPASSDB_VPOPMAIL
\-I../.. -I../lib userdb-vpopmail.c passdb-vpopmail.c -o vpopmail.so
\-lvpopmail

I had to modify the command to build the module, but was able to
successfully build it:
gcc -shared -fPIC -DHAVE_CONFIG_H -DUSERDB_VPOPMAIL -DPASSDB_VPOPMAIL
-I../.. -I../lib -I/home/vpopmail/include -I/home/vpopmail/lib
userdb-vpopmail.c passdb-vpopmail.c -o vpopmail.so
-L/home/vpopmail/lib/libvpopmail.a


I am unable to get the module to load properly.  Dovecot built with
--with-vpopmail works perfectly.  When I start dovecot and it tries to load
the module it reports:
Aug 23 16:48:18 ctd-nix1 dovecot: Dovecot v1.0.7 starting up
Aug 23 16:48:18 ctd-nix1 dovecot: auth(default):
dlopen(/usr/lib64/dovecot/auth/vpopmail.so) failed:
/usr/lib64/dovecot/auth/vpopmail.so: undefined symbol: vclose
Aug 23 16:48:18 ctd-nix1 dovecot: auth(default): dlsym(passdb_vpopmail)
failed: dovecot-auth: undefined symbol: passdb_vpopmail
Aug 23 16:48:18 ctd-nix1 dovecot: auth(default): Unknown passdb driver
'vpopmail' (typo, or Dovecot was built without support for it? Check with
dovecot --build-options)
Aug 23 16:48:18 ctd-nix1 dovecot: Auth process died too early - shutting
down

Sometimes instead the last line is replaced with:
Aug 23 15:02:45 ctd-nix1 dovecot: child 5412 (auth) returned error 89

Thanks!

Eric