#!/bin/sh
# tmww plugin: accsniffer
# whatis: wrapper around accsniffer util
# conflicts: pysniffer
# depends: alts
# recommends: -

# this file is part of tmww - the mana world watcher
# willee, 2012-2014
# GPL v3

# check if not run as plugin
if [ "$TMWW_PLUGINS" != "yes" ] ; then
    echo >&2 "This script is tmww plugin and rely heavily on it's facilities."
    exit 1
fi

help_accsniffer() {
    cat << EOF
accsniffer -- wrapper around accsniffer util
    Listen on all traffic from server, cut account ids, call alts plugin
    to store char info. One sniffer per server.

    Required setup for tcpick same as e.g. wireshark - changing tcpick
    group/adding user in group and setting tcpick capabilities:
    # setcap cap_net_raw,cap_net_admin=eip /usr/sbin/tcpick
    # usermod -a -G wireshark yourmom
    # chgrp wireshark /usr/sbin/tcpick

    Sniffer will crash if interface goes down. Don't forget to stop/start.

Command line options:
    -1 -- start | stop | status
EOF
}

[ "$TMWW_PLUGINHELP" = "yes" ] && help_accsniffer && return 0
# if someone by mistake export accsniffer
[ "$TMWW_PLUGINEXPORT" = "yes" ] && return 0

check_conflicts() {
    if [ -f ${LOCK}/sniffer.$servername ]; then
        error "Other sniffer listening on $servername. Aborting!"
        return 1
    fi
}

[ -z "${servername}" ] && { error "No servername defined. Aborting."; exit 1; }

# options parser
set -- $plugin_options
case "$1" in 
    start)
        if check_conflicts; then
            ${TMWW_UTILPATH}/accsniffer "${servername}" "${config}" >/dev/null 2>&1 &
            # if you see different kinds of errors like shell synthax error
            # reports , kill accsniffer process group by hand, stop and start
            # again
            # not sure why it happen, so added sleep as measure
            sleep 2
            sniffer_pgid=$(ps -o pgid= -C accsniffer)
            if [ -z "${sniffer_pgid}" ]; then
                echo Run failed! Check tcpick capabilities and permissions. Aborting!
                return 1
            else
                echo ${sniffer_pgid} > ${TMWW_LOCK}/sniffer.$servername
            fi
        fi
        ;;
    stop)
        [ -f ${TMWW_LOCK}/sniffer.$servername ] && {
            read sniffer_pgid < ${TMWW_LOCK}/sniffer.$servername
            [ -z "${sniffer_pgid}" ] || /bin/kill -9 -- -${sniffer_pgid}
            rm -f ${TMWW_LOCK}/sniffer.$servername
        }
        ;;
    status)
        if [ -f ${TMWW_LOCK}/sniffer.$servername ]; then
            read sniffer_pgid < ${TMWW_LOCK}/sniffer.$servername
            result=$( ps -Ao 'pgid=' | grep -- "${sniffer_pgid}" )
            if [ ! -z "${result}" ]; then
                echo Sniffer listening on $servername
            else
                error "Sniffer crashed. Restart manually!"
                return 1
            fi
        else
            echo No sniffer running on $servername
        fi
        ;;
    '') error_missing
        ;;
    *) error_incorrect
        ;;
esac

return 0