Raspberry Pi

The scope of this article is the installation steps taken to produce a local area network using a RaspberryPi 3, running Raspbian Jessy Lite, with a bridged internet connection via an Ethernet cable to facilitate both the Hackers & Designers workshops around basic Unix and program skills for designers, and the Frankenstein Bot workshop by Constant.

Code blocks that begin with "$" denote terminal, command line instructions, all other code blocks denote configuration files and/or program source code.

In all locations where "vi" is used, feel free to use another text editor of your choice (ex. nano).

Setting up the network

These instructions are taken largely from here, but are reiterated in the case article disappears from the internet.

We need to tell dhcpcd to ignore the wlan0 interface.

$ sudo vi /etc/dhcpcd.conf

Add the following line to the bottom of the file:

denyinterfaces wlan0

wlan0 will need a static ip address.

$ sudo vi /etc/network/interfaces

The file should contain, everything else can be commented out or deleted:

   auto lo
   iface lo inet loopback
   allow-hotplug eth0
   iface eth0 inet dhcp
   allow-hotplug wlan0
   iface wlan0 inet static
       address 10.1.1.1
       netmask 255.255.255.0
       network 10.1.1.0
       broadcast 10.1.1.255

Install hostapd, and configure it.

$ sudo apt-get install hostapd

$ sudo vi /etc/hostapd/hostapd.conf

   interface=wlan0
   driver=nl80211
   ssid=Hackers & Designers
   hw_mode=g
   channel=6
   ieee80211n=1
   wmm_enabled=1
   ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40]
   macaddr_acl=0
   ignore_broadcast_ssid=0

$ sudo vi /etc/default/hostapd

Uncomment and set the following value:

DAEMON_CONF="/etc/hostapd/hostapd.conf

Install and configure dnsmasq.

$ sudo apt-get install dnsmasq

   interface=wlan0
   listen-address=10.1.1.1
   bind-interfaces
   server=8.8.8.8
   domain-needed
   bogus-priv
   dhcp-range=10.1.1.50,10.1.1.250,12h

For the purposes of the Frankenstein "hovel" bot, also uncomment:

   log-queries
   log-dhcp

Setup IPv4 forwarding.

$ sudo vi /etc/sysctl.conf

Uncomment the following line.

net.ipv4.ip_forward=1

Execute the following.

   $ sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
   $ sudo iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
   $ sudo iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT
   $ sudo sh -c "iptables-save > /etc/iptables.ipv4.nat"

To ensure the forwarding persists beyond restarts.

$ sudo vi /etc/rc.local

Add the following line before exit(0).

iptables-restore < /etc/iptables.ipv4.nat

Restart and verify the network is working.

$ sudo reboot

Frankenstein Bots (IRC)

The Frankenstein bot project requires an IRC server. I use UnrealIRCd for this.

Install ssl.

$ sudo apt-get install libssl-dev

Download UnrealIRCd, for example (but maybe check the versions etc.).

$ wget 'https://www.unrealircd.org/unrealircd4/unrealircd-4.0.4.tar.gz'

Untar, change directory.

   $ tar -zxf unrealircd-4.0.4.tar.gz 
   $ cd unrealircd-4.0.4/

Configure.

$ ./Config

It will ask a lot of questions, I accepted all the defaults.

Build, Install.

   $ make
   $ make install

Start.

   $ cd ~/unrealircd
   $ ./unrealircd start

It may complain you need to create a configuration file. You can find how to do that here