-#!/bin/sh
-# -*- sh -*-
-
-: << =cut
+#!/usr/bin/perl -w
=head1 NAME
/etc/munin/plugin-conf.d/global or other file in that dir must contain:
- [fw*]
+ [fw_*]
user root
=head1 NOTES
-ESTABLISHED+FIN_WAIT+TIME_WAIT+SYN_SENT+UDP is the most interesting
+ESTABLISHED+FIN_WAIT+TIME_WAIT+SYN_SENT+UDP are the most interesting
connections.
The total list also includes SYN_RECV, CLOSE, CLOSE_WAIT, LAST_ACK and
ASSURED is after ACK is seen after SYN_RECV. Therefore ASSURED is
plotted but not UNREPLIED.
-NATed will almost always be the same as the total
-
-=head1 BUGS
-
-=over 4
-
-=item full connection table
-
-The connections tables can run full, but where is the limits found?
-If we can find them then we can send warnings to nagios.
-
-=back
+Note that the plugin depends on the netfilter "conntrack" userspace tool.
+It comes from http://conntrack-tools.netfilter.org/
=head1 AUTHORS
-2004.05.05: Initial version by Nicolai Langfeldt, Linpro AS, Oslo, Norway
-
-=head2 CONTRIBUTORS
+=over
-=over 4
+=item 2004.05.05: Initial version by Nicolai Langfeldt, Linpro AS, Oslo, Norway
-=item Xavier
+=item 2004.05.06: Enhanced to count NATed connections after input from Xavier on munin-users list
-2004.05.06: Enhanced to count NATed connections after input from Xavier on munin-users list
+=item 2011.09.23: Perl version by Alex Tomlins
=back
=cut
-case $1 in
- config)
-
- cat <<EOF
+use strict;
+use Munin::Plugin;
+
+my $conntrack = '/usr/sbin/conntrack';
+my $nf_conntrack_file = '/proc/net/nf_conntrack';
+my $ip_conntrack_file = '/proc/net/ip_conntrack';
+my @conntrack_max_files = qw(
+ /proc/sys/net/nf_conntrack_max
+ /proc/sys/net/netfilter/nf_conntrack_max
+ /proc/sys/net/ipv4/ip_conntrack_max
+ /proc/sys/net/ipv4/netfilter/ip_conntrack_max
+);
+
+if ( defined($ARGV[0]) and $ARGV[0] eq "autoconf" ) {
+ if ( -x $conntrack or -r $nf_conntrack_file or -r $ip_conntrack_file) {
+ print "yes\n";
+ } else {
+ print "no\n";
+ }
+ exit 0;
+}
+
+if ( defined($ARGV[0]) and $ARGV[0] eq "config" ) {
+ print <<EOF;
graph_title Connections through firewall
graph_vlabel Connections
graph_category network
total.type GAUGE
total.graph no
EOF
- if [ -f /proc/sys/net/ipv4/ip_conntrack_max ] ; then
- MAX=`cat /proc/sys/net/ipv4/ip_conntrack_max`
- elif [ -f /proc/sys/net/ipv4/netfilter/ip_conntrack_max ]; then
- MAX=`cat /proc/sys/net/ipv4/netfilter/ip_conntrack_max`
- fi
- if [ -n "$MAX" ]; then
- echo total.warning `expr $MAX \* 8 / 10`
- echo total.critical `expr $MAX \* 9 / 10`
- fi
- exit 0
- ;;
- autoconf)
- if [ -r /proc/net/ip_conntrack -o -r /proc/net/nf_conntrack ] ; then
- echo yes
- exit 0
- else
- echo no
- exit 0
- fi
-esac
-
-# Do the work, perform the deed
-
-# INPUT /proc/net/ip_conntrack:
-# tcp 6 225790 ESTABLISHED src=10.0.0.4 dst=198.144.194.12 sport=48580 dport=6667 src=198.144.194.12 dst=80.111.68.163 sport=6667 dport=48580 [ASSURED] use=1
-# tcp 6 431918 ESTABLISHED src=10.0.0.2 dst=209.58.150.153 sport=33018 dport=6667 src=209.58.150.153 dst=80.111.68.163 sport=6667 dport=33018 [ASSURED] use=1
-# tcp 6 123109 ESTABLISHED src=10.0.0.5 dst=198.144.194.12 sport=33846 dport=6667 [UNREPLIED] src=198.144.194.12 dst=80.111.68.163 sport=6667 dport=33846 use=1
-# udp 17 53 src=80.111.68.163 dst=62.179.100.29 sport=34153 dport=53 src=62.179.100.29 dst=80.111.68.163 sport=53 dport=34153 [ASSURED] use=1
-#
-# INPUT /proc/net/nf_conntrack:
-# ipv4 2 tcp 6 424416 ESTABLISHED src=192.168.1.53 dst=196.203.198.11 sport=1584 dport=22146 packets=13659 bytes=5426603 src=196.203.198.11 dst=83.24.222.252 sport=22146 dport=1584 packets=14757 bytes=15342572 [ASSURED] mark=0 use=1
-
-if [ -f /proc/net/ip_conntrack ]; then
- cat /proc/net/ip_conntrack | awk '
- BEGIN { STATE["ESTABLISHED"]=STATE["FIN_WAIT"]=STATE["TIME_WAIT"]=0;
- TOTAL=ASSURED=NOREPLY=NATED=STATE["SYN_SENT"]=STATE["UDP"]=0; }
- /^tcp/ { STATE[$4]++; }
- /^udp/ { STATE["UDP"]++; }
- /ASSURED/ { ASSURED++; }
- {
- TOTAL++;
- src1 = substr($5, 5); src2 = substr($9, 5);
- dst1 = substr($6, 5); dst2 = substr($10, 5);
- if (src1 != dst2 || dst1 != src2) NATED++;
- }
- END { print "established.value " STATE["ESTABLISHED"];
- print "fin_wait.value " STATE["FIN_WAIT"];
- print "time_wait.value " STATE["TIME_WAIT"];
- print "syn_sent.value " STATE["SYN_SENT"];
- print "udp.value " STATE["UDP"];
- print "assured.value " ASSURED;
- print "nated.value " NATED;
- print "total.value " TOTAL;
- }'
-else
- cat /proc/net/nf_conntrack | awk '
- BEGIN { STATE["ESTABLISHED"]=STATE["FIN_WAIT"]=STATE["TIME_WAIT"]=0;
- TOTAL=ASSURED=NOREPLY=NATED=STATE["SYN_SENT"]=STATE["UDP"]=0; }
- / tcp / { STATE[$6]++; }
- / udp / { STATE["UDP"]++; }
- /ASSURED/ { ASSURED++; }
- {
- TOTAL++;
- src1 = substr($7, 5); src2 = substr($14, 5);
- dst1 = substr($8, 5); dst2 = substr($15, 5);
- if (src1 != dst2 || dst1 != src2) NATED++;
- }
- END { print "established.value " STATE["ESTABLISHED"];
- print "fin_wait.value " STATE["FIN_WAIT"];
- print "time_wait.value " STATE["TIME_WAIT"];
- print "syn_sent.value " STATE["SYN_SENT"];
- print "udp.value " STATE["UDP"];
- print "assured.value " ASSURED;
- print "nated.value " NATED;
- print "total.value " TOTAL;
- }'
-fi
-
-# Hum, the total.value should be possible to do as a cdef.
-# Or to use the builtin "total" support.
-
-# LocalWords: expr
-
+ my $max;
+ foreach (@conntrack_max_files) {
+ if ( -r $_) {
+ chomp($max = `cat $_`);
+ last;
+ }
+ }
+ if ($max) {
+ print "total.warning ", $max * 8 / 10, "\n";
+ print "total.critical ", $max * 9 / 10, "\n";
+ }
+ exit 0;
+}
+
+my $command;
+if ( -x $conntrack) {
+ $command = "$conntrack -L -o extended -f ipv4 2>/dev/null; $conntrack -L -o extended -f ipv6 2>/dev/null";
+} elsif ( -r $nf_conntrack_file ) {
+ $command = "cat $nf_conntrack_file";
+} else {
+ $command = "cat $ip_conntrack_file";
+}
+
+my %state = (
+ 'ESTABLISHED' => 0,
+ 'FIN_WAIT' => 0,
+ 'TIME_WAIT' => 0,
+ 'SYN_SENT' => 0,
+ 'UDP' => 0,
+ 'ASSURED' => 0,
+ 'NATTED' => 0,
+ 'TOTAL' => 0
+);
+open CMD, "$command|";
+while (<CMD>) {
+ $state{'TOTAL'} ++;
+ $state{'UDP'} ++ if /udp /;
+ $state{'ASSURED'} ++ if /ASSURED/;
+ if (/tcp \s*\d+\s+\d+\s+(\S+)/) {
+ $state{$1} ++;
+ }
+ if (/src=(\S+)\s+dst=(\S+)\s+sport.*src=(\S+)\s+dst=(\S+)/) {
+ $state{'NATTED'} ++ if $1 ne $4 or $2 ne $3;
+ }
+}
+close CMD;
+
+print "established.value $state{'ESTABLISHED'}\n";
+print "fin_wait.value $state{'FIN_WAIT'}\n";
+print "time_wait.value $state{'TIME_WAIT'}\n";
+print "syn_sent.value $state{'SYN_SENT'}\n";
+print "udp.value $state{'UDP'}\n";
+print "assured.value $state{'ASSURED'}\n";
+print "nated.value $state{'NATTED'}\n";
+print "total.value $state{'TOTAL'}\n";