#!/bin/sh
#
# This file is part of gpgpy-ezmlm - an encryption filter for the
# ezmlm-idx mailinglist manager.
#
# Copyright 02007 Sense.Lab e.V. <info@senselab.org>
#
# This script is used to decide if we have to call qmail-queue directly
# or if we should call the gpgpy re-encrypting wrapper instead.
#
# Add the following environment setting to qmail-start (e.g. in
# /var/qmail/rc):
#  QMAILQUEUE=PATH_TO_THIS_SCRIPT
#
# In case you did not install qmail in its default directory (/var/qmail)
# or if you use a filtering qmail-queue wrapper (e.g. for spam filtering)
# then you should change the setting GPGPY_QMAILQUEUE so that it contains
# the path of your qmail-queue program.
#
#
# gpgpy-ezmlm is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
# 
# gpgpy-ezmlm is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with the CryptoBox; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#


##################### configuration #####################

# maybe you have to adjust the following lines according to your setup
# the following settings can also be overriden by environment settings
# with the same name

# the original qmail-queue program
GPGPY_QMAILQUEUE=${GPGPY_QMAILQUEUE:=/var/qmail/bin/qmail-queue}
# the python filter of gpgpy-ezmlm-queue
GPGPY_EZMLM_ENCRYPT=${GPGPY_EZMLM_ENCRYPT:=/usr/local/bin/gpgpy-ezmlm-encrypt}
# are all encrypted mailinglists handled by a single user?
# then put its UID here - for all other UIDs the original qmail-queue will be
# used instead
GPGPY_RESTRICT_UID=${GPGPY_RESTRICT_UID:=}

# we read our configuration from 'conf-gpgpy'
GPGPY_EZMLM_CONF_FILE="conf-gpgpy"
# call the original qmail-queue program without the changed QMAILQUEUE setting
EXEC_ORIG_QUEUE="exec env --unset=QMAILQUEUE $GPGPY_QMAILQUEUE"


##################### self-test #########################

# should we do some self-tests?
if test "$#" -eq 1 -a "$1" = "test"
  then	error=
	# check if the original qmail-queue is executable
	if test -x "$GPGPY_QMAILQUEUE"
	  then	true
	  else	error=yes
		echo >&2 "Could not find executable qmail-queue: $GPGPY_QMAILQUEUE"
	 fi

	# check if the gpgpy-ezmlm wrapper for qmail-queue exists
	# also check if it returns any errors
	if test -x "$GPGPY_EZMLM_ENCRYPT"
	  then	if "$GPGPY_EZMLM_ENCRYPT"
		  then	true
		  else	error=yes
		 fi 2>&1 | sed 's/^/[gpg-ezmlm-encrypt] /' >&2
	  else	error=yes
	  	echo >&2 "Could not find executable gpgpy-ezmlm-queue: $GPGPY_EZMLM_ENCRYPT"
	 fi

	# check GPGPY_RESTRICT_UID for invalid values
	if test -n "$GPGPY_RESTRICT_UID"
	  then	if test 0 -le "$GPGPY_RESTRICT_UID" 2>/dev/null
		  then	true
		  else	error=yes
			echo >&2 "Invalid value of GPGPY_RESTRICT_UID ($GPGPY_RESTRICT_UID) - only integer values are allowed!"
		 fi
	 fi

	# print results to stderr
	if test -z "$error"
	  then	echo "Successfully finished self-tests"
		exit 0
	  else	echo >&2
		echo >&2 "Some self-tests failed - please fix them before deploying gpgpy-ezmlm!"
	    exit 81
	 fi
 fi


################### queue selection #####################
# do some tests to decide, if we should run the gpgpy filter or not

test -n "$GPGPY_RESTRICT_UID" -a "$UID" != "$GPGPY_RESTRICT_UID" && $EXEC_ORIG_QUEUE

# the HOME setting is necessary
test -z "$HOME" && $EXEC_ORIG_QUEUE

# which dot-qmail file should we check? (see 'man qmail-command' for details)
if test -z "$EXT"
  then	DOTQMAIL_FILE=$HOME/.qmail
  else	DOTQMAIL_FILE=$HOME/.qmail-$EXT
 fi

# does the dot-qmail file exist?
test -r "$DOTQMAIL_FILE" || $EXEC_ORIG_QUEUE

# filter the respective mailing list directory of this delivery
MAILINGLIST_DIR=$(grep "/ezmlm-send '" "$DOTQMAIL_FILE" | cut -d "'" -f 2)

# is it a mailinglist directory?
test -e "$MAILINGLIST_DIR/lock" || $EXEC_ORIG_QUEUE

# is this mailinglist configured for gpgpy-ezmlm?
test -r "$MAILINGLIST_DIR/$GPGPY_EZMLM_CONF_FILE" || $EXEC_ORIG_QUEUE

# ok - it is a delivery of an encrypted mailinglist
exec env QMAILQUEUE=$GPGPY_QMAILQUEUE "$GPGPY_EZMLM_ENCRYPT" "$MAILINGLIST_DIR"