#!/bin/sh # # Copyright (c) 2010, Yavuz Gokirmak # # All rights reserved. # # This source code may be used, modified, copied, distributed, and # sold, in both source and binary form provided that the above # copyright and these terms are retained, verbatim, as the first # lines of this file. Under no circumstances is the author # responsible for the proper functioning of the software nor does # the author assume any responsibility for damages incurred with # its use. # # # This script adds virtual nodes to one of the physical interfaces # visible on your local area network (LAN). Virtual nodes seems real # to external observers. # If traceroute is executed to one of virtual nodes, the IP # address of the physical interface will not be seen in the output. # Virtual nodes are generated via jails and network connections are # established using ng_bridge(4) and ng_eiface(4) node types. # # To use this script: # # 0. Make your own copy of this example script. # # 1. Edit the definition of ${ETHER_INTF} as described below # to define your real interface connected to the LAN. Virtual nodes # will placed on the same physical network as this interface. # # 2. Edit the definition of ${TARGET_TOPOLOGY} to define your virtual # nodes. Virtual topology definition includes node names and their # IP address. Target top. syntax: ( node1|ip1/24 node2|ip2/24 ... ) # Example 1: ( n1|122.122.122.12/24, n2|122.122.122.13/24 ...) # Example 2: ( n1|2001:b90::14a/125, n1|2001:b90::14b/125 ...) # # 3. Run this script with "start" as the command line argument. # # 4. Stop bridging by running this script with "stop" as the # command line argument. # # 5. This script uses a template file in order to carry information # between start and stop calls. # In the start call, the netgraph interfaces and jails are created. # At the stop phase, all created objects should be removed. # DO NOT delete the temporary file between the start and stop phases. # # To add virtual nodes for multiple independent LANs, create multiple # copies of this script with different variable definitions. # # Target Topology: # # # +---------------+ +---------------+ +---------------+ # | n0 (vimage) | | n1 (vimage) | | nk (vimage) | # | | | | | | # | +-----------+ | | +-----------+ | | +-----------+ | # | | ngeth0 | | | | ngeth1 | | | | ngethk | | # | |(ng_eiface)| | | |(ng_eiface)| | | |(ng_eiface)| | # | +--+-----+--+ | | +--+-----+--+ | | +--+-----+--+ | # | |ether| | | |ether| | | |ether| | # | +--X--+ | | +--X--+ | | +---X-+ | # +-----+ +--------\------+ +--------\------+ +-------/-------+ # |upper|----\ \ip_addr \ip_addr /ip_addr # +-+-----+--+ \ \ \ \ # | em0 | \ +--------+ +-+ \ # |(ng_ether)| +-----------+ \ \ \ # +-+-----+--+ \ \ / \ # |lower| +---------\ \ \ / / # +--X--+ / O--X--O O-X---O O---X-O O--X--O O---X---O # \ | |link0| |link1| |link2| |link3| |linkk+2| # \ / +-O-----O-O-----O-O-----O-O-----O-----O-------O-+ # +---+ | | # | bridge (ng_bridge) | # +-----------------------------------------------+ # # # Give the name of ethernet interface. Virtual nodes will be seen as # local neighbours of this interface. ETHER_INTF="em0" # List the names of virtual nodes and their IP addresses. Use ':' # character to separate node name from node IP address and netmask. TARGET_TOPOLOGY="c1|10.0.2.20/24 c2|10.0.2.21/24 c3|10.0.2.22/24" # MAC manufacturer prefix. This can be modified according to needs. MAC_PREFIX="00:1d:92" # Temporary file is important for proper execution of script. TEMP_FILE="/var/tmp/.virtual.lan.tmp" # Set root directory for jails to be created. JAIL_PATH="/usr/jails/node" #################################################################### #### Nothing below this point should need to be modified. #### #################################################################### # Start/restart routine. virtual_lan_start() { # Load netgraph KLD's as necessary. for KLD in ng_ether ng_bridge ng_eiface; do if ! kldstat -v | grep -qw ${KLD}; then echo -n "Loading ${KLD}.ko... " kldload ${KLD} || exit 1 echo "done" fi done # Reset all interfaces and jails. If temporary file can not be found # script assumes that there is no previous configuration. if [ ! -e ${TEMP_FILE} ]; then echo "No previous configuration(${TEMP_FILE}) found to clean-up." else echo -n "Cleaning previous configuration..." virtual_lan_stop echo "done" fi # Create temporary file for usage. This file includes generated # interface names and jail names. All bridges, interfaces and jails # are written to file while created. In clean-up process written # objects are cleaned (i.e. removed) from system. if [ -e ${TEMP_FILE} ]; then touch ${TEMP_FILE} fi echo -n "Verifying ethernet interface existence..." # Verify ethernet interface exist. if ! ngctl info ${ETHER_INTF}: >/dev/null 2>&1; then echo "Error: interface ${ETHER_INTF} does not exist" exit 1 fi ifconfig ${ETHER_INTF} up || exit 1 echo "done" # Get current number of bridge interfaces in the system. This number # is used to create a name for new bridge. BRIDGE_COUNT=`ngctl l | grep bridge | wc -l | sed -e "s/ //g"` BRIDGE_NAME="bridge${BRIDGE_COUNT}" # Create new ng_bridge(4) node and attach it to the ethernet interface. # Connect ng_ether:lower hook to bridge:link0 when creating bridge and # connect ng_ether:upper hook to bridge:link1 after bridge name is set. echo "Creating bridge interface: ${BRIDGE_NAME}..." ngctl mkpeer ${ETHER_INTF}: bridge lower link0 || exit 1 ngctl name ${ETHER_INTF}:lower ${BRIDGE_NAME} || exit 1 ngctl connect ${ETHER_INTF}: ${BRIDGE_NAME}: upper link1 || exit 1 echo "Bridge ${BRIDGE_NAME} is created and ${ETHER_INTF} is connected." # In the above code block two hooks are connected to bridge interface, # therefore LINKNUM is set to 2 indicating total number of connected # hooks on the bridge interface. LINKNUM=2 # Write name of the bridge to temp file. Clean-up procedure will use # this name to shutdown bridge interface. echo "bridge ${BRIDGE_NAME}" > ${TEMP_FILE} # Attach other interfaces as well. for NODE in ${TARGET_TOPOLOGY}; do # Virtual nodes are defined in TARGET_TOPOLOGY variable. They # have the form of 'nodeName|IPaddr'. Below two lines split # node definition to get node name and node IP. NODE_NAME=`echo ${NODE} | awk -F"|" '{print $1}'` NODE_IP=`echo ${NODE} | awk -F"|" '{print $2}'` # Create virtual node (jail) with given name and using # JAIL_PATH as root directory for jail. echo -n "Creating virtual node (jail) ${NODE_NAME}..." jail -c vnet name=${NODE_NAME} host.hostname=${NODE_NAME} \ path=${JAIL_PATH} persist echo "done" # Write name of the jail to temp file. Clean-up procedure will # use this name to remove jail. echo "node ${NODE_NAME}" >> ${TEMP_FILE} # Create a ng_eiface object for virtual node. ng_eiface # object has a hook that can be connected to one of bridge # links. After creating interface get its automatically # generated name for further usage. echo "Creating eiface interface for virtual node ${NODE_NAME}." ngctl mkpeer eiface ether ether EIFACE=`ngctl l | grep ngeth | tail -n 1| awk '{print $2}'` echo "Interface ${EIFACE} is created." # Write name of the interface to temp file. Clean-up procedure # will use this name to shutdown interface. echo "interface ${EIFACE}" >> ${TEMP_FILE} # Move virtual interface to virtual node. Note that Interface # name will not be changed at the end of this movement. Moved # interface can be seen at the output of ifconfig command in # jail: 'jexec jailname ifconfig' echo "Moving ${EIFACE} to ${NODE_NAME}" ifconfig ${EIFACE} vnet ${NODE_NAME} # Make lo0 interface localhost. jexec ${NODE_NAME} ifconfig lo0 localhost # Generate a random mac address for virtual interface. First # three octets can be changed by user. Last three octets are # generated randomly. M4=`od -An -N2 -i /dev/random | sed -e 's/ //g' | \ awk '{ print $1 % 256 }'` M5=`od -An -N2 -i /dev/random | sed -e 's/ //g' | \ awk '{ print $1 % 256 }'` M6=`od -An -N2 -i /dev/random | sed -e 's/ //g' | \ awk '{ print $1 % 256 }'` MAC=`printf ${MAC_PREFIX}:%02x:%02x:%02x ${M4} ${M5} ${M6}` # Set the link address (mac address) of virtual interface in # virtual node to randomly generated MAC. echo "Setting MAC address of ${EIFACE} to '${MAC}'" jexec ${NODE_NAME} ifconfig ${EIFACE} link $MAC # Either IPv4 or IPv6 can be used in this script. Ifconfig # IP setting syntax differs slightly for two IP versions. # For version 4 'inet' keyword is used whereas for version 6 # 'inet6' is used. Below line tries to decide which IP version # is given and sets IPVER to 'inet' or 'inet6'. IPVER=`echo ${NODE_IP} | awk -F"." '{ split($4,last,"/"); \ if( NF==4 && $1>0 && $1<256 && $2<256 && $3<256 && \ last[1]<256) print "inet"; else print "inet6"}'` # Set IP address of virtual interface in virtual node. echo "Setting IP address of ${EIFACE} to '${NODE_IP}'" jexec ${NODE_NAME} ifconfig ${EIFACE} ${IPVER} ${NODE_IP} # Connect virtual interface to bridge interface. Syntax is : # ngctl connect INTERFACE: BRIDGE: INTERFACE_HOOK EMPTY_LINK. # Interface has one hook named 'ether' and below line connects # ether hook to bridge's first unconnected link. echo -n "Connecting ${EIFACE}:ether to ${BRIDGE_NAME}:link${LINKNUM}..." ngctl connect ${EIFACE}: ${BRIDGE_NAME}: ether link${LINKNUM} \ || exit 1 echo "done" # Now, bridge has one more connected link thus link count is # incremented. LINKNUM=`expr ${LINKNUM} + 1` done echo "Virtual LAN established successfully!" } # Stop routine. virtual_lan_stop() { if [ ! -e ${TEMP_FILE} ]; then echo "Nothing to stop! ${TEMP_FILE}: temp file not found" else echo -n "Shutdown bridge interface.." OBJECTS=`cat ${TEMP_FILE} | grep bridge | awk '{print $2}'` for BRIDGE in ${OBJECTS}; do ngctl shutdown ${BRIDGE}: >/dev/null 2>&1 done echo "done" echo -n "Shutdown all eiface interfaces..." OBJECTS=`cat ${TEMP_FILE} | grep interface | awk '{print $2}'` for INTERFACE in ${OBJECTS}; do ngctl shutdown ${INTERFACE}: >/dev/null 2>&1 done echo "done" echo -n "Removing all jails..." OBJECTS=`cat ${TEMP_FILE} | grep node | awk '{print $2}'` for NODE in ${OBJECTS}; do jail -r ${NODE} done echo "done" echo "Removing tempfile ${TEMP_FILE}" rm ${TEMP_FILE} fi echo "Virtual LAN objects removed successfully!" } virtual_lan_usage() { echo "usage: $0 start [target_topology]" echo " : $0 [ stop | help ]" } # Main entry point. case $# in 1) case $1 in start) echo -n "Creating default target topology:" echo " ${TARGET_TOPOLOGY}" virtual_lan_start ;; stop) if [ ! -e ${TEMP_FILE} ]; then echo -n "Noting to stop! ${TEMP_FILE}:" echo " temp file not found" else virtual_lan_stop fi ;; help) virtual_lan_usage exit 1 ;; *) virtual_lan_usage exit 1 esac ;; 2) case $1 in start) TARGET_TOPOLOGY=$2 echo -n "Creating target topology:" echo "${TARGET_TOPOLOGY}" virtual_lan_start ;; *) virtual_lan_usage exit 1 esac ;; *) virtual_lan_usage exit 1 esac