Install n2n-Supernode¶

Requirements¶

To install n2n you will need the following:

• a installed and supported operating system (e.g. CentOS 6.x)
• root-access
• EPEL repository
• a fast internet connection

Preliminary note¶

most of this is taken from

• [[http://www.ntop.org/products/n2n/]]
• [[https://github.com/lukablurr/n2n_v2_fork/blob/master/doc/multiple-supernodes.pdf]]
• [[http://listgateway.unipi.it/mailman/listinfo/n2n]]
• [[http://listgateway.unipi.it/pipermail/n2n/2009-October/000300.html]]

Install¶

yum install n2n

manual testing¶

starting Supernode¶

supernode -l 5422

setting up firewall¶

in order to access the supernode from one of the edge-clients the given UDP-port must be accessible from outside. Therefore we need to open the firewall.

system-config-firewall-tui

running n2n-Supernode as a service¶

if everything is working as expected we maybe want n2n-Supernode to survive a system-reboot.

The following should work without modification for RHEL/CentOS linux and similar:

Create a folder /etc/n2n and create configuration files (as described below) using following file name format:

mkdir /etc/n2n

supernode-gw1.example.com
supernode-gw2.example.com
supernode-*.example.com

The interesting contents of supernode-gw1.example.com would look similar to this:

vim /etc/n2n/supernode-gw1.example.com

# == supernode config values parsed by /etc/rc.d/init.d/edged ==
# Read 'man supernode' for details about these values...
#
# Example port number to listen on...
N2N_PORT="8765" 

# Verbose or not (-v logs to std out)...
#   N2N_OPTS="-v" 
N2N_OPTIONS="" 
# === end supernode-gw1.example.com config file
==========

Read comments in the scripts below to make more sense out of how they work.

Here are copies of some scripts that work when used with configuration files as described above:

vim /etc/init.d/supernoded

#!/bin/sh
# $Id: supernoded.init,v 1.9 2009/10/23 12:34:56
# n2n supernode startup script.
#
# chkconfig:    345 96 26
# processname:  supernode
# pidfile:      /var/run/n2n-supernode.pid
#
# short-description: Provides client-to-client VPN access via Internet
# description: This is startup script for n2n 'edge',
#   n2n edge + supernode provide internet connection for vpn peers
#
# SEE:
#   for more options n2n 'man edge' and 'man supernode'
#
# NOTE:
#   Option to enter 'debug' as second var: e.g 'supernode start debug'
#   Using grep -w switch searches for whole word reduces ambiguity
#   Comment in/out the 'echo' stuff depending if thigs work as expected
#   Config files located/named in: /etc/n2n/supernode-your.example.com
#   Assumes CentOS linux init scripts located in /etc/rc.d/init.d/
#
# Created: FOOFORCE RB 2009-10-24
# License GPL: free to copy, improve and use.
# http://fuji.unipi.it/pipermail/n2n/2009-October/000300.html
# ===============================================================

# ==== main init script variables ===============================
# Make sure you include path where 'supernode' + sh + tools are installed..
# PATH="/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin" 
PATH="/sbin:/bin:/usr/sbin:/usr/bin" 

# The name + path to the program/daemon...
NAME="supernode" 
DAEMON="/usr/sbin/${NAME}" 

# Modify $NAME to filter on 'grep -w [s]supernode' - faster than 'grep -v grep'...
GREPNAME=$(echo "[s]${NAME#s}")

# Enable some simple debug messages when running this script...
if [[ "${2}" == "debug" ]]; then
    echo "DEBUG: ${GREPNAME}" 
fi

PIDFILE="/var/run/supernode.pid" 
LOGFILE="/var/log/n2n-${NAME}.log" 
STAMP=$(/bin/date +"%d/%b/%Y %H:%M:%S")

# Get the host/domain name to identify local configfile..
HOST=$(/bin/hostname)
FQDN=$(/bin/hostname -f)

# Initialise configfile variable to empty value...
CONFIGDIR="/etc/n2n" 

# Initialise configfile variable to empty value...
CONFIGFILE="" 

# Source function library.
. /etc/rc.d/init.d/functions

# Load values from configfile using our local domain name:
# Example:
#   Our local FQDN = 'myhost.example.com'
#   Our configfile = 'supernode-myhost.example.com'
#
# if [[ "${HOST}" == "" ]]; then
if [[ "${FQDN}" == "" ]]; then
    echo " ERROR: Missing ${FQDN} hostname in config file /etc/rc.d/init.d/${NAME}" 
    exit 1
else
    CONFIGFILE="/etc/n2n/supernode-${FQDN}" 
fi

if [[ -f "${CONFIGFILE}" ]]; then
    # Get values from local configuration file...
    if [[ "${2}" ==  "debug" ]]; then
        echo " Found config file: ${CONFIGFILE}" 
    fi
    . ${CONFIGFILE}
else
    echo "ERROR: Missing config file ${CONFIGFILE}" 
    exit 1
fi

# See if pid file exists and get pid number...
if [[ -f "${PIDFILE}" ]]; then
    CURPID=$(cat ${PIDFILE})
fi

# Quit if we can't find application...
test -f ${DAEMON} || exit 0

set -e

# Set any value to enable this script...
# N2N_RUN=1
#
# test -n "${N2N_RUN}" || exit 0

# Optionaly change into n2n config directory...
if [[ -d "${CONFIGDIR}" ]]; then
    cd ${CONFIGDIR}
fi
# ==============================================================
# Should not need to change much below here...
# ==== see how we were called  + act accordingly ===============

if [ "${N2N_PORT}" == "" ]; then
    N2N_PORT="1304" 
    echo "No port specified in ${CONFIGFILE} - using  default port: ${N2N_PORT}" 
fi

case "${1}" in
    start)
        # echo " ${NAME} ${1} process is ${0} on pid: ${$})..." 
        echo "${STAMP} start n2n /etc/rc.d/init.d/${NAME}" >> ${LOGFILE}

        if [[ -n "${CURPID}" ]]; then
            echo " A PID:${CURPID} already exists for ${0}:" 
            echo " To re-start with current config settings, run '$0 stop' then '$0 start' ..." 
        else
        if [ -d /var/lock/subsys ] ; then
            touch /var/lock/subsys/${NAME};
        fi

            # ====================================================
            # All variables read from ${CONFIGFILE}...
            # If variable value not empty then add command-line switch to variable...
            if [[ -n "${N2N_PORT}" ]]; then
                N2N_PORT="-l ${N2N_PORT}";
            fi

            # next line for debug:
            if [[ "${2}" == "debug" ]]; then
                echo " DEBUG: ${DAEMON} ${N2N_PORT} ${N2N_OPTIONS}" 
            fi

            # Execute the command + switches + values sources from config file...
            echo -n $"Starting $NAME: " 
            ${DAEMON} ${N2N_PORT} ${N2N_OPTIONS} >> ${LOGFILE} &
            RETVAL=$?

            [ $RETVAL -eq 0 ] && echo_success
            [ $RETVAL -ne 0 ] && echo_failure
            echo

            # =================================================
            if [[ "${2}" ==  "debug" ]]; then
                echo " NOTICE: Creating new ${NAME} pidfile - deleting old ${CURPID}..." 
            fi

            rm -f ${PIDFILE}
            touch ${PIDFILE}

            for PID in $(ps ax | grep -w "${GREPNAME}" | grep -v "(restart|stop|start)" | awk '{ print $1 }'); do
                if [[ "${2}" ==  "debug" ]]; then
                    echo " Saving into pidfile - new pid: ${PID}" 
                fi
                echo ${PID} >> ${PIDFILE}
            done
        fi
        ;;
    stop)
        # echo " DEBUG: Searching for at least one live process id..." 
        PID=$(ps ax | grep -w "${GREPNAME}" | grep -v "(restart|stop|start)" | awk '{ print $1 }')

        if [[ "${2}" == "debug" ]]; then
            echo " This ${NAME} ${1} init query ${0} is running on pid: ${$}) for ${PID}..." 
        fi

        # echo " ${NAME} ${1} process is ${0} on pid: ${$})..." 
        echo "${STAMP} stop /etc/rc.d/init.d/${NAME}" >> ${LOGFILE}

        # echo "  NOTICE: Kill name:${NAME} pid:${pid} before stopping..." 
        # kill -9 $(cat /var/run/${NAME}_pid) && rm /var/run/${NAME}_pid

        # If a pid value found in file or in process id, then kill it...
        if [[ -n "${PID}" ]]; then
            echo -n  $"Stopping ${NAME}: " 
            # kill -9 $(cat /var/run/${NAME}.pid) && rm /var/run/${NAME}.pid
            kill ${PID}
            RETVAL=$?
            sleep 4s
            rm -f ${PIDFILE}
            if [ $RETVAL -eq 0 ] ; then
                echo_success
                echo
            else
                echo_failure
                echo
            fi
        else
            # Else assume stale pid...
            if [[ "${2}" == "debug" ]]; then
                echo " NOTICE: No current active process ${PID}..." 
            fi

            if [[ -f "${PIDFILE}" ]]; then
                rm -f "${PIDFILE}" 
            fi
        fi

        # Indiscriminate pid killer...
        # for PID in $(ps ax | grep -w ${NAME} | grep -v stop | awk '{ print $1 }'); do
        #    echo " Killing currently active ${NAME} pid(s): ${PID}" 
        #    # kill -HUP $PID
        #    kill ${PID}
        # done

        if [ -f /var/lock/subsys/${NAME} ]; then
            if [[ "${2}" ==  "debug" ]]; then
                echo " Removing stale lock..." 
            fi
            rm -f /var/lock/subsys/${NAME}
        fi

        if [ -f "${PIDFILE}" ]; then
            echo " Removing stale pidfile..." 
            rm -f ${PIDFILE}
        fi
        ;;
    restart)
        echo "* Re-start ${NAME}..." 
        ${0} stop ${2}

        # Not a race...
        sleep 4s

        ${0} start ${2}
        ;;
    status)
        # status ${NAME}

        if [[ "${2}" == "debug" ]]; then
            echo " This init script ${NAME} ${1} query ${0} is running on pid: ${$})..." 
        fi

        PID=$(ps ax | grep -w "${GREPNAME}" | grep -v status | awk '{ print $1 }')

        # If at least one active session then find all...
        if [[ -n "${PID}" ]]; then
            for PID in $(ps ax | grep -w "${GREPNAME}" | grep -v status | awk '{ print $1 }'); do
                if [[ -n "${PID}" ]]; then
                    echo "${NAME} (pid ${PID}) is running..." 
                else
                    echo "${NAME} is stopped" 
                fi
            done
        else
            echo "${NAME} is stopped" 
        fi
        ;;
    *)
        echo " Usage: ${0} {start|stop|status|restart|any debug}" >&2
        exit 1
        ;;
esac
exit 0
# === end supernoded ======================================

make init-script executeable

chmod +x /etc/init.d/supernoded

Using CentOS tools to activate the systemV init scripts:

chkconfig --add supernoded
chkconfig supernoded on

Command line syntax:

service supernoded [start|stop|restart|any debug]

For example:

service supernoded restart

… OR…

service supernoded restart debug

provides some extra clues.