#!/bin/sh
# -*- sh -*-

: << =cut

=head1 NAME

dspam_activity - Plugin to monitor DSPAM message handling activities.

=head1 APPLICABLE SYSTEMS

Any system running a recent (3.8.0 or higher) DSPAM install.

=head1 CONFIGURATION

The plugin uses the contents of the SystemLog or UserLog produced by DSPAM.

The following environment variables are used by this plugin:

 logfile - Where to find the system.log that is written by dspam
          (default: /var/spool/dspam/system.log)

=head2 CONFIGURATION EXAMPLES

 [dspam_activity]
  env.logfile /opt/dspam/var/spool/dspam/system.log
  # or when monitoring only a single user in stead of all users:
  env.logfile /var/spool/dspam/data/example.org/username/username.log

=head1 USAGE

Link this plugin to /etc/munin/plugins/ and restart the munin-node.

You'll need to enable system logging in dspam.conf, set 'SystemLog on'
in the DSPAM configuration file.

=head1 INTERPRETATION

The graph shows the messages that DSPAM has processed over the monitored
period, and what kind of action was taken on it. Possible activities are:

 Received messages can be classified as:
 - Innocent (I)
 - Spam (S)
 - Auto-whitelist (W)
 - Virus (V)
 - Blocklist (O)
 - Blacklist (RBL) (A)
 Other actions:
 - Retrained as spam (M)
 - Retrained as innocent (F)
 - Inoculation (N)
 - Corpusfed (C)

Please see DSPAM documentation for more information on used terminology. The
single character in parentheses is the DSPAM internal name for the classifications.

=head1 AUTHOR

Copyright 2010-2011 Tom Hendrikx <tom@whyscream.net>

=head1 LICENSE

GPLv2

This program 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; version 2 dated June, 1991.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

=head1 BUGS

None known. Please report to author when you think you found something.

=head2 TODO LIST

=head1 VERSION

$Id: dspam_activity 139 2011-08-04 20:03:22Z tomhendr $

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf

=cut

# defaults for configurable settings
: ${logfile:=/var/spool/dspam/system.log}
: ${statefile:=$MUNIN_STATEFILE}

# include munin plugin helper
. $MUNIN_LIBDIR/plugins/plugin.sh

##########################
# Some generic functions #
##########################

#
# debug $message
#	Prints debugging output when munin-run is called with --pidebug argument (i.e. when MUNIN_DEBUG is set)
#
debug() {
	if [ -n "$MUNIN_DEBUG" ]; then
		echo "# DEBUG: $@"
	fi
}

#
# get_activity_description $activity $type
#	Return textual descriptions for the various activities
#
get_activity_description() {
	local activity=$1
	local type=$2

	# defaults
	local short="Unknown ($activity)"
	local long="Unknown ($activity)"

	# Possible activities: I S W V O A M F N C
	case $activity in
		I) short=Innocent long="Messages received and classified as innocent" ;;
		S) short=Spam long="Messages received and classified as spam" ;;
		W) short=Auto-whitelisted long="Messages received and auto-whitelisted" ;;
		V) short=Virus long="Messages received and classified as virus by Clamav" ;;
		O) short=Blocklisted long="Messages received but not classified because the sender domain is on to the user blocklist" ;;
		A) short="Blacklisted (RBL)" long="Message received and classified as spam because the sender ip is listed on the RBL" ;;
		M) short="Retrained as spam" long="Messages classified as innocent, but retrained by user as spam" ;;
		F) short="Retrained as innocent" long="Messages classified as spam, but retrained by the user as innocent" ;;
		N) short=Inoculation long="Messages trained as spam through inoculation" ;;
		C) short=Corpusfed long="Messages fed from a corpus" ;;
	esac

	[ "$type" = "short" ] && echo $short && return
	[ "$type" = "long" ] && echo $long && return
}

########################################
# Functions that generate munin output #
########################################

#
# print_autoconf
#	Output for 'munin-node-configure autoconf' functionality
#
print_autoconf() {
	if [ ! -r $logfile ]; then
		echo "no (logfile $logfile does not exist or not readable)"
	else
		echo yes
	fi
}

#
# print_config
#	Output for 'munin-run <plugin> config' command.
#
print_config() {
	debug printing config

	echo "graph_title DSPAM activity"
	echo graph_category spamfilter
	echo graph_args --base 1000
	echo graph_vlabel Messages / \${graph_period}
	echo graph_period minute

	for activity in I S W V O A M F N C; do
		local label="$(get_activity_description $activity short)"
		local info="$(get_activity_description $activity long)"
		echo $activity.label $label
		echo $activity.info $info
		echo $activity.draw AREASTACK
		echo $activity.type DERIVE
		echo $activity.min 0
	done

	debug finished printing config
}

#
# print_fetch
#	Output for 'munin-run <plugin> fetch' command: the actual data to graph.
#
print_fetch() {
	debug printing fetch

	local old_ts
	[ -r $statefile ] && old_ts=$(cat $statefile)
	if [ -n "$old_ts" ]; then
		debug read timestamp $old_ts from statefile

		# sample from system.log:
		# 1285144434<tab>M<tab>"Dr.Abdul Qahaar" <dr.abdulqahaar@sify.com><tab>2,4c99980137698241679684 \
		#  <tab>Business Proposal / Partnership Investment<tab>1.256280<tab>username@example.org<tab>Retrained<tab><421586.75972.qm@web120402.mail.ne1.yahoo.com>

		if [ -r $logfile ]; then

			# Possible activities: I S W V O A M F N C
			local aI=0 aS=0 aW=0 aV=0 aO=0 aA=0 aM=0 aF=0 aN=0 aC=0

			local skipped=0 processed=0
			local old_IFS=$IFS
			IFS="	" # tab-separator in $logfile
			while read ts activity from signature subject x recipient info msgid; do
				if ! [ $ts -gt 0 2> /dev/null ]; then
					debug skipped entry with non-numeric timestamp: $ts
				elif [ $ts -gt $old_ts ]; then
					debug processing entry with timestamp $ts, activity=$activity, subject=$subject, msgid=$msgid
					case $activity in
						I) aI=$((aI + 1)) ;;
						S) aS=$((aS + 1)) ;;
						W) aW=$((aW + 1)) ;;
						V) aV=$((aV + 1)) ;;
						O) aO=$((aO + 1)) ;;
						A) aA=$((aA + 1)) ;;
						M) aM=$((aM + 1)) ;;
						F) aF=$((aF + 1)) ;;
						N) aN=$((aN + 1)) ;;
						C) aC=$((aC + 1)) ;;
						*) debug unknown activity $activity found, subject=$subject, msgid=$msgid ;;
					esac

					processed=$((processed + 1))
				else
					skipped=$((skipped + 1))
				fi
			done < $logfile
			IFS=$old_IFS
			debug skipped $skipped lines in logfile because timestamp was too old
			debug processed $processed lines in logfile

			# show results
			echo I.value $aI
			echo S.value $aS
			echo W.value $aW
			echo V.value $aV
			echo O.value $aO
			echo A.value $aA
			echo M.value $aM
			echo F.value $aF
			echo N.value $aN
			echo C.value $aC
		else
			debug logfile not available $logfile
			exit 66 # EX_NOINPUT
		fi
	else
		debug could not read timestamp from statefile
		# no exit here, we need the next operation to write a timestamp in the statefile
	fi

	# update statefile with current timestamp
	local new_ts=$(date +%s)
	echo $new_ts > $statefile
	debug timestamp in statefile updated to $new_ts, old was $old_ts

	debug finished printing fetch
}


#####################
# Main process loop #
#####################

# show env settings
debug dspam_activity plugin started, pid=$$
debug settings:
debug - logfile is set to: $logfile
debug - statefile is set to: $statefile

command=$1
[ -n "$command" ] || command="fetch"
debug - command is set to: $command

debug settings completed, starting process

case $command in
	autoconf)
		print_autoconf
		;;
	config)
		print_config
		;;
	fetch)
		print_fetch
		;;
esac

debug exiting
exit 0 # EX_OK