#!/bin/sh

: <<EOF

=head1 NAME

tcp - Plugin to monitor IPV4/6 TCP socket status on a Linux host.

=head1 AUTHOR

Copyright 2009 Tim Small <tim@seoss.co.uk>

=head1 LICENSE

GPLv2

=begin comment

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.

=end comment

=head1 MAGIC MARKERS

 #%# family=manual
 #%# capabilities=autoconf

=cut

EOF

case $1 in
    config)
        cat <<EOF
graph_title TCP
graph_vlabel TCP Sockets
graph_category network
graph_args -l 0
graph_info TCP socket states for the local machine
EOF

		for i in established syn_sent syn_recv fin_wait1 \
			fin_wait2 time_wait close close_wait last_ack \
			listen closing
		do
			echo "${i}.label $i"
			echo "${i}.info Sockets in state $i"
		done

        exit 0
		;;
    autoconf)
        if [ -f /proc/net/tcp ] || [ -f /proc/net/tcp6 ]
		then
			echo yes
			exit 0
		else
			echo no
			exit 0
		fi
esac

# See #include <netinet/tcp.h>

cat /proc/net/tcp* | awk '

  match ($4, /0[0-9A-B]/) {
      STATE[$4]++;
  }

  END {
      printf "established.value %d\n", STATE["01"];
      printf "syn_sent.value %d\n",    STATE["02"];
      printf "syn_recv.value %d\n",    STATE["03"];
      printf "fin_wait1.value %d\n",   STATE["04"];
      printf "fin_wait2.value %d\n",   STATE["05"];
      printf "time_wait.value %d\n",   STATE["06"];
      printf "close.value %d\n",       STATE["07"];
      printf "close_wait.value %d\n",  STATE["08"];
      printf "last_ack.value %d\n",    STATE["09"];
      printf "listen.value %d\n",      STATE["0A"];
      printf "closing.value %d\n",     STATE["0B"];
  }'
