Plugins Support on AIX

How to build Dovecot with plugins supported on AIX.

Tested with:

AIX 5.2, VAC 5.0.2 and Dovecot 1.0rc21 to 1.0.13 (Dovecot 1.1.x does not build with VAC 5.0.2)
AIX 5.2, VAC 8.0.0 and Dovecot 1.1.1

The Problem

When you trying to use plugins on AIX you seen error messages like this:

imap(root): Error:
dlopen(/usr/local/lib/dovecot/imap/lib20_zlib_plugin.so) failed:
rtld: 0712-001 Symbol i_error was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
rtld: 0712-001 Symbol i_stream_get_data was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
rtld: 0712-001 Symbol i_stream_skip was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
rtld: 0712-001 Symbol i_stream_seek was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
rtld: 0712-001 Symbol i_stream_close was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
rtld: 0712-001 Symbol i_panic was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
rtld: 0712-001 Symbol pool_get_exp_grown_size was referenced
      from module /usr/local/lib/dovecot/imap/lib20_zlib_plugin.so(),
      but a runtime definition of the symbol was not found.
Additional errors occurred but are not reported.

.. produced by executing

# MAIL_PLUGINS=zlib /usr/local/libexec/dovecot/imap

Compiler Script

Create a compiler script to rewrite the xlc command line on the fly: dovecot-cc

#!/bin/bash

xlc=/usr/bin/xlc
ar=/bin/ar
sed=/bin/sed

dest=NOBINARY

for i in "$@"; do
        case "$i" in
        '-o')  dest=;;
        *)     if [ -z "$dest" ]; then dest="$i"; break; fi;;
        esac
done

case "$dest" in
imap-login) args1="../lib-charset/libcharset.a ../lib-mail/libmail.a -liconv";;
imap)       args1="../lib-sql/libsql.a";;
pop3)       args1="../lib-sql/libsql.a";;
deliver)    args1="../lib-sql/libsql.a";;
esac

for i in "$@" $args1; do
        case "$i" in   
        */*.a) lib="${i##*/}"; obj=`$ar -t $i | $sed "s:^:${i%/*}/:"`;;
        *.a)   lib="$i";       obj=`$ar -t $i | $sed "s:^:./:"`;;
        *)     continue;;                       
        esac
        test -d .libs || mkdir .libs
        > .libs/${lib%.a}.exp      
        args2="$args2 -bE:.libs/${lib%.a}.exp"

        (set -x ; exec $xlc -qmkshrobj -qexpfile=.libs/${lib%.a}.exp $obj) 2>/dev/null
done
(set -x ; exec $xlc "$@" $args1 $args2)

Compiling Dovecot

Expand Dovecot:

gzip -cd doveccot-1.0.rc21.tar.gz | tar xvf -

Setup build environment:

export CC=$PWD/dovecot-cc
export LDFLAGS="-bexpall -brtl"

Configure and build Dovecot

cd dovecot-1.0.rc21
bash configure 
make

Test a plugin (e.g. zlib)

echo 0 logout | MAIL_PLUGIN_DIR=src/plugins/zlib/.libs/ MAIL_PLUGINS="zlib" src/imap/imap

you should see this:

* PREAUTH [CAPABILITY IMAP4rev1 SASL-IR SORT THREAD=REFERENCES MULTIAPPEND UNSELECT LITERAL+ IDLE CHILDREN NAMESPACE LOGIN-REFERRALS] Logged in as root
* BYE Logging out
0 OK Logout completed.
imap(root): Info: Disconnected: Logged out

Install Dovecot
```
make install
```

Prebuild Binaries for AIX 5.2

You will find prebuild AIX 5.2 binaries here: http://www.fh-trier.de/~beckerr/dovecot/