1#!/bin/sh 2# 3# Copyright (c) 2010, Yavuz Gokirmak 4# 5# All rights reserved. 6# 7# This source code may be used, modified, copied, distributed, and 8# sold, in both source and binary form provided that the above 9# copyright and these terms are retained, verbatim, as the first 10# lines of this file. Under no circumstances is the author 11# responsible for the proper functioning of the software nor does 12# the author assume any responsibility for damages incurred with 13# its use. 14# 15# $FreeBSD$ 16# 17# This script adds virtual nodes to one of the physical interfaces 18# visible on your local area network (LAN). Virtual nodes seems real 19# to external observers. 20# If traceroute is executed to one of virtual nodes, the IP 21# address of the physical interface will not be seen in the output. 22# Virtual nodes are generated via jails and network connections are 23# established using ng_bridge(4) and ng_eiface(4) node types. 24# 25# To use this script: 26# 27# 0. Make your own copy of this example script. 28# 29# 1. Edit the definition of ${ETHER_INTF} as described below 30# to define your real interface connected to the LAN. Virtual nodes 31# will placed on the same physical network as this interface. 32# 33# 2. Edit the definition of ${TARGET_TOPOLOGY} to define your virtual 34# nodes. Virtual topology definition includes node names and their 35# IP address. Target top. syntax: ( node1|ip1/24 node2|ip2/24 ... ) 36# Example 1: ( n1|122.122.122.12/24, n2|122.122.122.13/24 ...) 37# Example 2: ( n1|2001:b90::14a/125, n1|2001:b90::14b/125 ...) 38# 39# 3. Run this script with "start" as the command line argument. 40# 41# 4. Stop bridging by running this script with "stop" as the 42# command line argument. 43# 44# 5. This script uses a template file in order to carry information 45# between start and stop calls. 46# In the start call, the netgraph interfaces and jails are created. 47# At the stop phase, all created objects should be removed. 48# DO NOT delete the temporary file between the start and stop phases. 49# 50# To add virtual nodes for multiple independent LANs, create multiple 51# copies of this script with different variable definitions. 52# 53# Target Topology: 54# 55# 56# +---------------+ +---------------+ +---------------+ 57# | n0 (vimage) | | n1 (vimage) | | nk (vimage) | 58# | | | | | | 59# | +-----------+ | | +-----------+ | | +-----------+ | 60# | | ngeth0 | | | | ngeth1 | | | | ngethk | | 61# | |(ng_eiface)| | | |(ng_eiface)| | | |(ng_eiface)| | 62# | +--+-----+--+ | | +--+-----+--+ | | +--+-----+--+ | 63# | |ether| | | |ether| | | |ether| | 64# | +--X--+ | | +--X--+ | | +---X-+ | 65# +-----+ +--------\------+ +--------\------+ +-------/-------+ 66# |upper|----\ \ip_addr \ip_addr /ip_addr 67# +-+-----+--+ \ \ \ \ 68# | em0 | \ +--------+ +-+ \ 69# |(ng_ether)| +-----------+ \ \ \ 70# +-+-----+--+ \ \ / \ 71# |lower| +---------\ \ \ / / 72# +--X--+ / O--X--O O-X---O O---X-O O--X--O O---X---O 73# \ | |link0| |link1| |link2| |link3| |linkk+2| 74# \ / +-O-----O-O-----O-O-----O-O-----O-----O-------O-+ 75# +---+ | | 76# | bridge (ng_bridge) | 77# +-----------------------------------------------+ 78# 79# 80 81# Give the name of ethernet interface. Virtual nodes will be seen as 82# local neighbours of this interface. 83 84ETHER_INTF="em0" 85 86# List the names of virtual nodes and their IP addresses. Use ':' 87# character to separate node name from node IP address and netmask. 88 89TARGET_TOPOLOGY="c1|10.0.2.20/24 c2|10.0.2.21/24 c3|10.0.2.22/24" 90 91# MAC manufacturer prefix. This can be modified according to needs. 92MAC_PREFIX="00:1d:92" 93 94# Temporary file is important for proper execution of script. 95TEMP_FILE="/var/tmp/.virtual.lan.tmp" 96 97# Set root directory for jails to be created. 98JAIL_PATH="/usr/jails/node" 99 100 101#################################################################### 102#### Nothing below this point should need to be modified. #### 103#################################################################### 104 105 106# Start/restart routine. 107virtual_lan_start() { 108 109 # Load netgraph KLD's as necessary. 110 111 for KLD in ng_ether ng_bridge ng_eiface; do 112 if ! kldstat -v | grep -qw ${KLD}; then 113 echo -n "Loading ${KLD}.ko... " 114 kldload ${KLD} || exit 1 115 echo "done" 116 fi 117 done 118 119 # Reset all interfaces and jails. If temporary file can not be found 120 # script assumes that there is no previous configuration. 121 122 if [ ! -e ${TEMP_FILE} ]; then 123 echo "No previous configuration(${TEMP_FILE}) found to clean-up." 124 else 125 echo -n "Cleaning previous configuration..." 126 virtual_lan_stop 127 echo "done" 128 fi 129 130 # Create temporary file for usage. This file includes generated 131 # interface names and jail names. All bridges, interfaces and jails 132 # are written to file while created. In clean-up process written 133 # objects are cleaned (i.e. removed) from system. 134 135 if [ -e ${TEMP_FILE} ]; then 136 touch ${TEMP_FILE} 137 fi 138 139 echo -n "Verifying ethernet interface existence..." 140 # Verify ethernet interface exist. 141 if ! ngctl info ${ETHER_INTF}: >/dev/null 2>&1; then 142 echo "Error: interface ${ETHER_INTF} does not exist" 143 exit 1 144 fi 145 ifconfig ${ETHER_INTF} up || exit 1 146 echo "done" 147 148 # Get current number of bridge interfaces in the system. This number 149 # is used to create a name for new bridge. 150 BRIDGE_COUNT=`ngctl l | grep bridge | wc -l | sed -e "s/ //g"` 151 BRIDGE_NAME="bridge${BRIDGE_COUNT}" 152 153 # Create new ng_bridge(4) node and attach it to the ethernet interface. 154 # Connect ng_ether:lower hook to bridge:link0 when creating bridge and 155 # connect ng_ether:upper hook to bridge:link1 after bridge name is set. 156 157 echo "Creating bridge interface: ${BRIDGE_NAME}..." 158 ngctl mkpeer ${ETHER_INTF}: bridge lower link0 || exit 1 159 ngctl name ${ETHER_INTF}:lower ${BRIDGE_NAME} || exit 1 160 ngctl connect ${ETHER_INTF}: ${BRIDGE_NAME}: upper link1 || exit 1 161 echo "Bridge ${BRIDGE_NAME} is created and ${ETHER_INTF} is connected." 162 163 # In the above code block two hooks are connected to bridge interface, 164 # therefore LINKNUM is set to 2 indicating total number of connected 165 # hooks on the bridge interface. 166 LINKNUM=2 167 168 # Write name of the bridge to temp file. Clean-up procedure will use 169 # this name to shutdown bridge interface. 170 echo "bridge ${BRIDGE_NAME}" > ${TEMP_FILE} 171 172 173 # Attach other interfaces as well. 174 for NODE in ${TARGET_TOPOLOGY}; do 175 176 # Virtual nodes are defined in TARGET_TOPOLOGY variable. They 177 # have the form of 'nodeName|IPaddr'. Below two lines split 178 # node definition to get node name and node IP. 179 180 NODE_NAME=`echo ${NODE} | awk -F"|" '{print $1}'` 181 NODE_IP=`echo ${NODE} | awk -F"|" '{print $2}'` 182 183 # Create virtual node (jail) with given name and using 184 # JAIL_PATH as root directory for jail. 185 186 echo -n "Creating virtual node (jail) ${NODE_NAME}..." 187 jail -c vnet name=${NODE_NAME} host.hostname=${NODE_NAME} \ 188 path=${JAIL_PATH} persist 189 echo "done" 190 191 # Write name of the jail to temp file. Clean-up procedure will 192 # use this name to remove jail. 193 194 echo "node ${NODE_NAME}" >> ${TEMP_FILE} 195 196 # Create a ng_eiface object for virtual node. ng_eiface 197 # object has a hook that can be connected to one of bridge 198 # links. After creating interface get its automatically 199 # generated name for further usage. 200 201 echo "Creating eiface interface for virtual node ${NODE_NAME}." 202 ngctl mkpeer eiface ether ether 203 EIFACE=`ngctl l | grep ngeth | tail -n 1| awk '{print $2}'` 204 echo "Interface ${EIFACE} is created." 205 206 # Write name of the interface to temp file. Clean-up procedure 207 # will use this name to shutdown interface. 208 209 echo "interface ${EIFACE}" >> ${TEMP_FILE} 210 211 # Move virtual interface to virtual node. Note that Interface 212 # name will not be changed at the end of this movement. Moved 213 # interface can be seen at the output of ifconfig command in 214 # jail: 'jexec jailname ifconfig' 215 216 echo "Moving ${EIFACE} to ${NODE_NAME}" 217 ifconfig ${EIFACE} vnet ${NODE_NAME} 218 219 # Make lo0 interface localhost. 220 jexec ${NODE_NAME} ifconfig lo0 localhost 221 222 # Generate a random mac address for virtual interface. First 223 # three octets can be changed by user. Last three octets are 224 # generated randomly. 225 M4=`od -An -N2 -i /dev/random | sed -e 's/ //g' | \ 226 awk '{ print $1 % 256 }'` 227 M5=`od -An -N2 -i /dev/random | sed -e 's/ //g' | \ 228 awk '{ print $1 % 256 }'` 229 M6=`od -An -N2 -i /dev/random | sed -e 's/ //g' | \ 230 awk '{ print $1 % 256 }'` 231 232 MAC=`printf ${MAC_PREFIX}:%02x:%02x:%02x ${M4} ${M5} ${M6}` 233 234 # Set the link address (mac address) of virtual interface in 235 # virtual node to randomly generated MAC. 236 echo "Setting MAC address of ${EIFACE} to '${MAC}'" 237 jexec ${NODE_NAME} ifconfig ${EIFACE} link $MAC 238 239 # Either IPv4 or IPv6 can be used in this script. Ifconfig 240 # IP setting syntax differs slightly for two IP versions. 241 # For version 4 'inet' keyword is used whereas for version 6 242 # 'inet6' is used. Below line tries to decide which IP version 243 # is given and sets IPVER to 'inet' or 'inet6'. 244 245 IPVER=`echo ${NODE_IP} | awk -F"." '{ split($4,last,"/"); \ 246 if( NF==4 && $1>0 && $1<256 && $2<256 && $3<256 && \ 247 last[1]<256) print "inet"; else print "inet6"}'` 248 249 # Set IP address of virtual interface in virtual node. 250 echo "Setting IP address of ${EIFACE} to '${NODE_IP}'" 251 jexec ${NODE_NAME} ifconfig ${EIFACE} ${IPVER} ${NODE_IP} 252 253 # Connect virtual interface to bridge interface. Syntax is : 254 # ngctl connect INTERFACE: BRIDGE: INTERFACE_HOOK EMPTY_LINK. 255 # Interface has one hook named 'ether' and below line connects 256 # ether hook to bridge's first unconnected link. 257 258 echo -n "Connecting ${EIFACE}:ether to ${BRIDGE_NAME}:link${LINKNUM}..." 259 ngctl connect ${EIFACE}: ${BRIDGE_NAME}: ether link${LINKNUM} \ 260 || exit 1 261 echo "done" 262 263 # Now, bridge has one more connected link thus link count is 264 # incremented. 265 LINKNUM=`expr ${LINKNUM} + 1` 266 done 267 echo "Virtual LAN established successfully!" 268 269} 270 271# Stop routine. 272virtual_lan_stop() { 273 274 if [ ! -e ${TEMP_FILE} ]; then 275 echo "Nothing to stop! ${TEMP_FILE}: temp file not found" 276 else 277 278 echo -n "Shutdown bridge interface.." 279 OBJECTS=`cat ${TEMP_FILE} | grep bridge | awk '{print $2}'` 280 for BRIDGE in ${OBJECTS}; do 281 ngctl shutdown ${BRIDGE}: >/dev/null 2>&1 282 done 283 echo "done" 284 285 echo -n "Shutdown all eiface interfaces..." 286 OBJECTS=`cat ${TEMP_FILE} | grep interface | awk '{print $2}'` 287 for INTERFACE in ${OBJECTS}; do 288 ngctl shutdown ${INTERFACE}: >/dev/null 2>&1 289 done 290 echo "done" 291 292 echo -n "Removing all jails..." 293 OBJECTS=`cat ${TEMP_FILE} | grep node | awk '{print $2}'` 294 for NODE in ${OBJECTS}; do 295 jail -r ${NODE} 296 done 297 echo "done" 298 299 echo "Removing tempfile ${TEMP_FILE}" 300 rm ${TEMP_FILE} 301 fi 302 echo "Virtual LAN objects removed successfully!" 303 304} 305 306virtual_lan_usage() { 307 echo "usage: $0 start [target_topology]" 308 echo " : $0 [ stop | help ]" 309} 310 311 312# Main entry point. 313 314case $# in 315 1) 316 case $1 in 317 start) 318 echo -n "Creating default target topology:" 319 echo " ${TARGET_TOPOLOGY}" 320 virtual_lan_start 321 ;; 322 stop) 323 324 if [ ! -e ${TEMP_FILE} ]; then 325 echo -n "Noting to stop! ${TEMP_FILE}:" 326 echo " temp file not found" 327 else 328 virtual_lan_stop 329 fi 330 ;; 331 help) 332 virtual_lan_usage 333 exit 1 334 ;; 335 *) 336 virtual_lan_usage 337 exit 1 338 339 esac 340 ;; 341 2) 342 case $1 in 343 start) 344 TARGET_TOPOLOGY=$2 345 echo -n "Creating target topology:" 346 echo "${TARGET_TOPOLOGY}" 347 virtual_lan_start 348 ;; 349 *) 350 virtual_lan_usage 351 exit 1 352 esac 353 ;; 354 355 *) 356 virtual_lan_usage 357 exit 1 358esac 359 360