#!/usr/bin/perl -w
#
# Plugin to monitor amavisd-new statistics.  Values are retrieved by querying
# the BerkeleyDB database 'snmp.db', in which amavisd-new stores its
# statistics.
#
# The plugin requires the Perl module BerkeleyDB.
#
# To use, setup /etc/munin/plugin-conf.d/amavis e.g. as follows:
#
#   [amavis_*]
#   env.amavis_db_home /var/lib/amavis/db
#   user amavis
#
# Where env.amavis_db_home is the path to the amavisd-new BerkeleyDB files
# (/var/amavis/db by default).
#
# Then create symlinks in the Munin plugin directory named "amavis_time",
# "amavis_cache" and "amavis_content", or use munin-node-configure.
#
# Parameters:
#
#	config
#	autoconf
#	suggest
#
# Config variables:
#
#       amavis_db_home   - where the amavisd-new berkeley db files are located
#
# Magic markers
#%# family=auto
#%# capabilities=autoconf
#%# capabilities=suggest

use strict;
no warnings 'uninitialized';

use BerkeleyDB;

my($dbfile) = 'snmp.db';
my($db_home) =  # DB databases directory
  defined $ENV{'amavis_db_home'} ? $ENV{'amavis_db_home'} : '/var/amavis/db';

if ($ARGV[0] and $ARGV[0] eq "autoconf") {
	if (-x "/usr/sbin/amavisd-agent") {
		print "yes\n";
	} else {
		print "no (/usr/sbin/amavisd-agent not found or not executable)\n";
	}
	exit 0;
} elsif ($ARGV[0] and $ARGV[0] eq "suggest") {
	print "time\n";
	print "cache\n";
	print "content\n";
	exit 0;
}

my $stats_type = "";
if ($0 =~ /^(?:|.*\/)amavis_(cache|content|time)$/) {
	$stats_type = $1;
} else {
	print "You need to create a symlink to this plugin called either amavis_cache, amavis_time or amavis_content to be able to use it.\n";
	exit 2;
}

if ($ARGV[0] and $ARGV[0] eq "config") {
	if ($stats_type eq "cache") {
		print "graph_title Amavis cache hit / miss ratio\n";
		print "graph_args --lower-limit 0 --upper-limit 100 --rigid\n";
		print "graph_category antivirus\n";
		print "graph_info The ratio of cache hits and misses for AMaViSd-new.\n";
		print "graph_order hits misses\n";
		print "graph_scale no\n";
		print "graph_vlabel %\n";
		print "hits.label Cache hits\n";
		print "hits.draw AREA\n";
		print "hits.max 100\n";
		print "hits.min 0\n";
		print "misses.label Cache misses\n";
		print "misses.draw STACK\n";
		print "misses.max 100\n";
		print "misses.min 0\n";
	} elsif ($stats_type eq "content") {
		print "graph_title Amavis scanned mails\n";
		print "graph_category antivirus\n";
		print "graph_period minute\n";
		print "graph_vlabel msgs / \${graph_period}\n";
		foreach my $type (qw(total clean spam spammy virus)) {
			print "$type.label " . ucfirst($type) . " mails \n";
			print "$type.type DERIVE\n";
			print "$type.min 0\n";
		}
		print "clean.info Legitimate mail.\n";
		print "spammy.info Mails with a spam score above the tag2 level.\n";
		print "spam.info Mails with a spam score above the kill level for spam.\n";
		print "virus.info Mails with a virus.\n";
		print "total.info Total number of scanned mails.\n";
	} elsif ($stats_type eq "time") {
		print "graph_title Amavis average scan time\n";
		print "graph_info Average time spent in each phase of the mail scanning process, per mail.\n";
		print "graph_category antivirus\n";
		print "graph_vlabel sec / mail\n";
		print "graph_scale no\n";

		print "msgs.label Total number of messages\n";
		print "msgs.graph no\n";
		print "msgs.type DERIVE\n";
		print "msgs.min 0\n";

		foreach my $type (qw(decoding receiving sending spamcheck viruscheck total)) {
			print "${type}.label " . ucfirst($type) . "\n";
			print "${type}.type DERIVE\n";
			print "${type}.min 0\n";
			print "${type}.cdef ${type},1000,/,msgs,/\n";
		}
	}
	exit 0;
}


my ($env, $db, @dbstat, $cursor);

@dbstat = stat("$db_home/$dbfile");
my $errn = @dbstat ? 0 : 0+$!;
$errn == 0 or die "stat $db_home/$dbfile: $!";

$env = BerkeleyDB::Env->new(
	-Home => $db_home,
	-Flags => DB_INIT_CDB | DB_INIT_MPOOL,
	-ErrFile => \*STDOUT,
	-Verbose => 1,
);
defined $env or die "BDB no env: $BerkeleyDB::Error $!";

$db = BerkeleyDB::Hash->new(-Filename => $dbfile, -Env => $env);
defined $db or die "BDB no db: $BerkeleyDB::Error $!";

my %values = ();
my ($eval_stat, $stat, $key, $val);

$cursor = $db->db_cursor;  # obtain read lock
defined $cursor or die "db_cursor error: $BerkeleyDB::Error";

while (($stat = $cursor->c_get($key, $val, DB_NEXT)) == 0) {
	$values{$key} = $val;
}

$stat == DB_NOTFOUND  or die "c_get: $BerkeleyDB::Error $!";
$cursor->c_close == 0 or die "c_close error: $BerkeleyDB::Error";
$cursor = undef;

$eval_stat = $@;

if ($eval_stat ne '') { chomp($eval_stat); die "BDB $eval_stat\n"; }

for my $k (sort keys %values) {
	if ($values{$k} =~ /^(?:C32|C64) (.*)\z/) {
		$values{$k} = $1;
	}
}

if ($stats_type eq "cache") {
	my $hits = $values{'CacheHits'};
	my $misses = $values{'CacheMisses'};
	my $misses_ratio = $misses * 100.00 / ($hits + $misses);
	my $hits_ratio = $hits * 100.00 / ($hits + $misses);

	printf("hits.value %.1f\n", $hits_ratio);
	printf("misses.value %.1f\n", $misses_ratio);
} elsif ($stats_type eq "content") {
	printf("total.value %d\n", $values{'InMsgs'});
	my $clean = $values{'ContentCleanMsgs'};
	if (defined($values{'ContentCleanTagMsgs'})) {
		$clean += $values{'ContentCleanTagMsgs'};
	}
	printf("clean.value %d\n", $clean);
	printf("spam.value %d\n", $values{'ContentSpamMsgs'});
	printf("spammy.value %d\n", $values{'ContentSpammyMsgs'});
	printf("virus.value %d\n", $values{'ContentVirusMsgs'});
} elsif ($stats_type eq "time") {
	printf("decoding.value %d\n", $values{'TimeElapsedDecoding'});
	printf("receiving.value %d\n", $values{'TimeElapsedReceiving'});
	printf("sending.value %d\n", $values{'TimeElapsedSending'});
	printf("spamcheck.value %d\n", $values{'TimeElapsedSpamCheck'});
	printf("viruscheck.value %d\n", $values{'TimeElapsedVirusCheck'});
	printf("total.value %d\n", $values{'TimeElapsedTotal'});
	printf("msgs.value %d\n", $values{'InMsgs'});
}

$db->db_close == 0 or die "BDB db_close error: $BerkeleyDB::Error $!";