RaspberryPi/July 2020

Startup

Wipe SD Cards

Wipe SD cards and install raspbian

Mount SD Cards

Mount the SD cards as a local filesystem on a Linux box

Now, if you want to modify the file /foo/bar, you can edit the file on the SD card at /media/ubuntu/rootfs/foo/bar

Enable SSH

Touch a file named ssh in the boot sector of the SD card to enable the service to start on boot:

touch /media/ubuntu/boot/ssh

Wifi

Set up wpa supplicant config file for your local wifi network

https://charlesreid1.com/wiki/Ubuntu/Bespin#Configure_WPA_Supplicant

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="YOURWIFINETWORK"
    proto=RSN
    key_mgmt=WPA-PSK
    pairwise=CCMP TKIP
    group=CCMP TKIP
    psk="YOURWIFIPASSWORD"
}

Network Interfaces

Next set up the WPA supplicant service to automatically start for our wifi device

Update the contents of your network interfaces file to look like this:

/etc/network/interfaces

source-directory /etc/network/interfaces.d

allow-hotplug lo
iface lo inet loopback

allow-hotplug wlan0
iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

Power up the Pi

Next time you boot up the Pi you should see your wifi card light blinking.

Try running an nmap scan for port 22 before and after the pi is plugged in, from another computer on the same network:

nmap -p22 192.168.0.0/24 > nmap-before

# plug in the pi, wait a few minutes

nmap -p22 192.168.0.0/24 > nmap-after

assuming your home wifi is 192.168.0.0/24.

Troubleshooting

If you need to troubleshoot, power off the Pi and re-mount the SD card on a Linux box. Check the syslog at /media/ubuntu/rootfs/var/log/syslog and see what's going on.

Thing 1

Installing PIA on Thing 1

This sets up a VPN tunnel at tun0 that connects to a PIA VPN server.

Run these commands as sudo:

# install openvpn
apt-get -y install openvpn

# set up pia
cd /tmp
wget https://www.privateinternetaccess.com/openvpn/openvpn.zip
unzip -d openvpn openvpn.zip
cd openvpn

# pick a profile to install
mv 'US West.ovpn' 'West.ovpn'
PROFILE="West"
cp ca.rsa.2048.crt /etc/openvpn/.
cp crl.rsa.2048.pem /etc/openvpn/.
cp ${PROFILE}.ovpn /etc/openvpn/.

# set up login credentials for PIA
touch /etc/openvpn/login
echo "USERNAME" >> /etc/openvpn/login
echo "PASSWORD" >> /etc/openvpn/login
chown root:root /etc/openvpn/login
chmod 600 /etc/openvpn/login

# modify openvpn service to use .ovpn files intead of .conf files, and set absolute paths
sed -i 's+^auth-user-pass+& /etc/openvpn/login+' /etc/openvpn/${PROFILE}.ovpn
sed -i 's+^ca ca.rsa.2048.crt+& /etc/openvpn/ca.rsa.2048.crt+' /etc/openvpn/${PROFILE}.ovpn
sed -i 's+^crl-verif crl.rsa.2048.pem+& /etc/openvpn/crl.rsa.2048.pem+' /etc/openvpn/${PROFILE}.ovpn
sed -i 's+\.conf+.ovpn+' /lib/systemd/system/openvpn@.service

# start openvpn
openvpn --config /etc/openvpn/${PROFILE}.ovpn

Once you have verified it is working, cancel the openvpn process and run the openvpn service:

systemctl enable openvpn@${PROFILE}
systemctl start openvpn@${PROFILE}

Verify it is working:

curl -4 icanhazip.org

and verify it is working.

Connect Thing 1 to internet

At this point, you will need an internet connection, plus an unoccupied wifi device.

You can leave the first wifi card alone as it is, and plug in a second wifi card (wlan1).

Or, you can connect an ethernet cable (eth0) and use wlan0 to run the hostapd.

We use the first scenario.

Hostapd on Thing 1

First allow the Pi to forward packets and act as a router by adding this line to your sysctl config:

/etc/sysctl.conf

net.ipv4.ip_forward=1

Reload the sysctl:

sudo sysctl --system

Install hostapd:

sudo apt-get -y install hostapd

Configure hostapd file:

/etc/hostapd/hostapd.conf

interface=wlan1
driver=nl80211
hw_mode=g
channel=1
macaddr_acl=0
ignore_broadcast_ssid=0

# LAN10
ssid=LAN10
wpa_passphrase=cow-doctor-horse-building-5
auth_algs=1
wpa=3
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP

Connecting Hostapd and PIA

Next step is to connect the hostapd network to the PIA tunnel so all traffic from clients on the hostapd wifi network will pass through the PIA tunnel.

Thing 2

Installing PiHole on Thing 2

This one is pretty easy. The one-liner, once you've inspected the code you're about to run (OF COURSE), is:

curl -sSL https://install.pi-hole.net | sudo bash

Normally it's bad practice to pipe to sudo bash, but this time around we make an exception. Ya know. Cuz we do like we do. You don't like it, you fuck off, you hear?

Now where was I.

To make the PiHole work for everyone on the local network, you need to enable the PiHole to respond to DNS queries from other hosts.

Boot up the Pi and go to the admin interface at 192.168.0.A/admin. Navigate to the Settings, then the DNS tab, and pick the option to respond to all queries from computers that are one hop away (local devices).

Installing PIA on Thing 2

Follow the steps above to install PIA on Thing 2.

Connecting PiHole to PIA

Next step is to set up PIA on Thing 2 so that all DNS queries will pass through a PIA tunnel.

Related Pages

RaspberryPi

RaspberryPi/Headless