OpenWRT + BATMAN + CoovaChilli

Objective

Build a captive portal on a wireless mesh network

Wireless clients can roam around the mesh network

Requirements

OpenWRT compatible router

OpenWRT

B.A.T.M.A.N.

CoovaChilli

FreeRadius

Topology

OpenWRT

Installation

• Download appropriate OpenWRT image from http://downloads.openwrt.org/snapshots/trunk/ 
• Connect your computer to the router
• Turn on the router
• Follow the router’s manual on upgrading its firmware but instead of using the manufacturer’s upgraded firmware, use the downloaded OpenWRT image

Configuration

For the configuration, we just need to set a password for the root user account

• Using Telnet, login to the router. A router with a newly installed OpenWRT has a default IP address of 192.168.1.1. Your telnet command should be
  

telnet 192.168.1.1

• Once logged in type passwd then Enter and provide a password for the root user account
• Logout by typing exit then press Enter

Testing

First we test if OpenWRT can access the Internet

• Connect the WAN port of the router to the Internet
• Login to the router using ssh (use root and the password you just set during configuration respectively)
• Now do a ping test to see if the router is indeed connected to the Internet

Now We’ll test the wireless interface of the router

• Still logged in to the router, edit /etc/config/wireless
• Delete the line that says “option disabled 1”
• Optionally set the SSID (This is the line that says option ssid ‘OpenWRT’. Change OpenWRT to your chosen SSID)
• Save and close the file
• Type wifi and press Enter to reload wifi configuration
• Connect to the router through its wireless interface. You should be able to access the Internet

B.A.T.M.A.N.

Installation

• Login to the router
• Connect the router to the Internet
• Execute the following

opkg update

opkg install kmod-batman-adv

Configuration

• Create a file /tmp/batman_config.sh and set the content with the following

#!/bin/sh

### Node-specific settings

export HOSTNAME="ROUTERNAME" 

export IP="192.168.1.1" 

export LAN_IFNAME="eth0 bat0"

### Network-specific settings should be consistent across all nodes with in the mesh network

export PUBLIC_ESSID="OMNISPOT" 

export NETMASK="255.255.255.0" 

export DNS="" 

export GATEWAY="" 

export MESH0_BSSID="CA:CA:CA:CA:CA:00" 

export MESH0_ESSID="mesh0" 

export MESH0_CHANNEL="3" 

wifi detect >>/etc/config/wireless

( for i in `seq 0 9` ; do echo "delete wireless.@wifi-iface[]" ; done ) | uci batch -q

uci import -m batman-adv </dev/null

echo " 

set system.@system[0].hostname=$HOSTNAME

set batman-adv.bat0=mesh

set batman-adv.bat0.interfaces='mesh0'

set batman-adv.bat0.gw_mode='off'

set network.lan.ipaddr=$IP

set network.lan.netmask=$NETMASK

set network.lan.dns='$DNS'

set network.lan.gateway=$GATEWAY

set network.lan.ifname='$LAN_IFNAME'

set network.bat0=interface

set network.bat0.ifname=bat0

set network.bat0.proto=none

set network.bat0.mtu=1500

set network.mesh0=interface

set network.mesh0.proto=none

set network.mesh0.mtu=1528

set wireless.radio0=wifi-device

set wireless.radio0.channel=$MESH0_CHANNEL

set wireless.radio0.disabled=0

set wireless.radio0.phy=phy0

set wireless.radio0.macaddr=

add wireless wifi-iface

set wireless.@wifi-iface[-1].device=radio0

set wireless.@wifi-iface[-1].encryption=none

set wireless.@wifi-iface[-1].network=lan

set wireless.@wifi-iface[-1].mode=ap

set wireless.@wifi-iface[-1].ssid='$PUBLIC_ESSID'

add wireless wifi-iface

set wireless.@wifi-iface[-1].device=radio0 

set wireless.@wifi-iface[-1].encryption=none

set wireless.@wifi-iface[-1].network=mesh0

set wireless.@wifi-iface[-1].mode=adhoc 

set wireless.@wifi-iface[-1].bssid=$MESH0_BSSID

set wireless.@wifi-iface[-1].ssid='$MESH0_ESSID'

set wireless.@wifi-iface[-1].mcast_rate=11000 

set dhcp.lan.ignore=1

commit" \

| uci batch

• Set the values of the node-specific settings for each router

Name	Description
HOSTNAME	Would-be hostname of the router
IP	Would-be IP address of the router
LAN_IFNAME	LAN interface name of the router and bat0 (B.A.T.M.A.N. interface)

• Set the network specific-settings. These should be the same for all nodes in the mesh network

Name	Description
PUBLIC_ESSID	The SSID of the wireless network where clients will connect to
NETMASK	Network mask of the mesh network
DNS	The DNS setting
GATEWAY	Internet gateway address
MESH0_BSSID	A common MAC address to enable the nodes of the mesh network to identify each other and communicate
MESH0_ESSID	The SSID for the mesh network
MESH0_CHANNEL	The channel to use for wireless communication

• Save and close the file /tmp/batman_config.sh
• Run the batman configuration script

sh /tmp/batman_config.sh

• Restart the router

Do this for all the routers involve 

Testing

• Turn on all the routers
• Log in to one of the routers
• You should be able to ping the other router

CoovaChilli

Installation

• Login to the router
• Connect the router to the Internet
• Execute the following

opkg update

opkg install coova-chilli

Configuration

• Execute the following on your computer

wget http://ap.coova.org/chilli/coova-chilli-1.3.0.tar.gz .

tar -xzvf coova-chilli-1.3.0.tar.gz

cd coova-chilli-1.3.0/miniportal

ls *.in | sed 's/\(.*\)\.in/\1/' | xargs -I {} mv {}.in {}

• Substitute the markers @SBINDIR@ and @ETCCHILLI@ with “/usr/sbin” and “/etc/chilli” respectively
• Copy the content of miniportal folder to the router

scp * root@192.168.1.1:/etc/chilli/www/

• Logon to the router
• Open /etc/chilli/defaults and edit the following settings

Key	Recommended Value	Remarks
HS_WANIF	eth1 or eth0.2	The WAN interface Uncomment this and set the value to the name of the WAN of the router Use ifconfig to give you a hint
HS_LANIF	bat0	The LAN interface bat0 is the name of the mesh network interface

• Choose either of the two for authentication

RADIUS Authentication

• For radius authentication, provide the IP address of the RADIUS server as value for key HS_RADIUS in /etc/chilli/defaults

Local File Authentication

• For local file authentication, uncomment the line HS_LOCALUSERS in /etc/chilli/defaults
• Create the file /etc/chilli/localusers and add the username and password in the following format

username:password:

Replace the marker username and password for the actual username and password. Use one line for each entry

• Restart the router

Testing

• Use a tablet or a PC to connect to the mesh network
• Open a browser and type in a URL

Conclusion

After you have installed and configured everything, you should have a captive portal working on a wireless mesh network. All DHCP request are handled by the gateway running CoovaChilli. And Internet access is controlled by CoovaChilli.