3 # Copyright (c) 2010, Yavuz Gokirmak
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
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.
27 # 0. Make your own copy of this example script.
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.
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 ...)
39 # 3. Run this script with "start" as the command line argument.
41 # 4. Stop bridging by running this script with "stop" as the
42 # command line argument.
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.
50 # To add virtual nodes for multiple independent LANs, create multiple
51 # copies of this script with different variable definitions.
56 # +---------------+ +---------------+ +---------------+
57 # | n0 (vimage) | | n1 (vimage) | | nk (vimage) |
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-+
76 # | bridge (ng_bridge) |
77 # +-----------------------------------------------+
81 # Give the name of ethernet interface. Virtual nodes will be seen as
82 # local neighbours of this interface.
86 # List the names of virtual nodes and their IP addresses. Use ':'
87 # character to separate node name from node IP address and netmask.
89 TARGET_TOPOLOGY="c1|10.0.2.20/24 c2|10.0.2.21/24 c3|10.0.2.22/24"
91 # MAC manufacturer prefix. This can be modified according to needs.
94 # Temporary file is important for proper execution of script.
95 TEMP_FILE="/var/tmp/.virtual.lan.tmp"
97 # Set root directory for jails to be created.
98 JAIL_PATH="/usr/jails/node"
101 ####################################################################
102 #### Nothing below this point should need to be modified. ####
103 ####################################################################
106 # Start/restart routine.
107 virtual_lan_start() {
109 # Load netgraph KLD's as necessary.
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
119 # Reset all interfaces and jails. If temporary file can not be found
120 # script assumes that there is no previous configuration.
122 if [ ! -e ${TEMP_FILE} ]; then
123 echo "No previous configuration(${TEMP_FILE}) found to clean-up."
125 echo -n "Cleaning previous configuration..."
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.
135 if [ -e ${TEMP_FILE} ]; then
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"
145 ifconfig ${ETHER_INTF} up || exit 1
148 # Get current number of bridge interfaces in the system. This number
149 # is used to create a name for new bridge.
150 BRIDGE_COUNT=`ngctl l | grep bridge | wc -l | sed -e "s/ //g"`
151 BRIDGE_NAME="bridge${BRIDGE_COUNT}"
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.
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."
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.
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}
173 # Attach other interfaces as well.
174 for NODE in ${TARGET_TOPOLOGY}; do
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.
180 NODE_NAME=`echo ${NODE} | awk -F"|" '{print $1}'`
181 NODE_IP=`echo ${NODE} | awk -F"|" '{print $2}'`
183 # Create virtual node (jail) with given name and using
184 # JAIL_PATH as root directory for jail.
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
191 # Write name of the jail to temp file. Clean-up procedure will
192 # use this name to remove jail.
194 echo "node ${NODE_NAME}" >> ${TEMP_FILE}
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.
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."
206 # Write name of the interface to temp file. Clean-up procedure
207 # will use this name to shutdown interface.
209 echo "interface ${EIFACE}" >> ${TEMP_FILE}
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'
216 echo "Moving ${EIFACE} to ${NODE_NAME}"
217 ifconfig ${EIFACE} vnet ${NODE_NAME}
219 # Make lo0 interface localhost.
220 jexec ${NODE_NAME} ifconfig lo0 localhost
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 }'`
232 MAC=`printf ${MAC_PREFIX}:%02x:%02x:%02x ${M4} ${M5} ${M6}`
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
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'.
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"}'`
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}
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.
258 echo -n "Connecting ${EIFACE}:ether to ${BRIDGE_NAME}:link${LINKNUM}..."
259 ngctl connect ${EIFACE}: ${BRIDGE_NAME}: ether link${LINKNUM} \
263 # Now, bridge has one more connected link thus link count is
265 LINKNUM=`expr ${LINKNUM} + 1`
267 echo "Virtual LAN established successfully!"
274 if [ ! -e ${TEMP_FILE} ]; then
275 echo "Nothing to stop! ${TEMP_FILE}: temp file not found"
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
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
292 echo -n "Removing all jails..."
293 OBJECTS=`cat ${TEMP_FILE} | grep node | awk '{print $2}'`
294 for NODE in ${OBJECTS}; do
299 echo "Removing tempfile ${TEMP_FILE}"
302 echo "Virtual LAN objects removed successfully!"
306 virtual_lan_usage() {
307 echo "usage: $0 start [target_topology]"
308 echo " : $0 [ stop | help ]"
318 echo -n "Creating default target topology:"
319 echo " ${TARGET_TOPOLOGY}"
324 if [ ! -e ${TEMP_FILE} ]; then
325 echo -n "Noting to stop! ${TEMP_FILE}:"
326 echo " temp file not found"
345 echo -n "Creating target topology:"
346 echo "${TARGET_TOPOLOGY}"