configure

#!/bin/bash
# The script configures simultaneous AP and Managed Mode Wifi on Raspberry Pi Zero W (should also work on Raspberry Pi 3)
# Licence: GPLv3
# Author: Darko Lukic <lukicdarkoo@gmail.com>
# Special thanks to: https://albeec13.github.io/2017/09/26/raspberry-pi-zero-w-simultaneous-ap-and-managed-mode-wifi/
# Special thanks to: https://raspberrypi.stackexchange.com/questions/89803/access-point-as-wifi-router-repeater-optional-with-bridge/118877#118877

# Error management
set -o errexit
set -o pipefail
set -o nounset

usage() {
    cat 1>&2 <<EOF
Configures simultaneous AP and Managed Mode Wifi on Raspberry Pi

USAGE:
    rpi-wifi -a <ap_ssid> [<ap_password>] -c <client_ssid> [<client_password>]
    
    rpi-wifi -a MyAP myappass -c MyWifiSSID mywifipass

PARAMETERS:
    -a, --ap      	AP SSID & password
    -c, --client	Client SSID & password
    -i, --ip            AP IP

FLAGS:
    -n, --no-internet   Disable IP forwarding
    -h, --help          Show this help
EOF
    exit 0
}

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -c|--client)
    CLIENT_SSID="$2"
    CLIENT_PASSPHRASE="$3"
    shift
    shift
    shift
    ;;
    -a|--ap)
    AP_SSID="$2"
    AP_PASSPHRASE="$3"
    shift
    shift
    shift
    ;;
    -i|--ip)
    ARG_AP_IP="$2"
    shift
    shift
    ;;
    -h|--help)
    usage
    shift
	;;
    -n|--no-internet)
    NO_INTERNET="true"
    shift
    ;;
    *)
    POSITIONAL+=("$1")
    shift
    ;;
esac
done
set -- "${POSITIONAL[@]}"

[ $AP_SSID ] || usage

AP_IP=${ARG_AP_IP:-'192.168.10.1'}
AP_IP_BEGIN=`echo "${AP_IP}" | sed -e 's/\.[0-9]\{1,3\}$//g'`
COUNTRY="$(wpa_cli -i wlan0 get country)"

# Install dependencies
sudo apt -y update
sudo apt -y upgrade
sudo apt -y install dnsmasq hostapd

# Exclude ap0 from `/etc/dhcpcd.conf`
sudo bash -c 'cat >> /etc/dhcpcd.conf' << EOF

# this defines static addressing to ap@wlan0 and disables wpa_supplicant for this interface
interface ap@wlan0
    static ip_address=${AP_IP}/24
    ipv4only
    nohook wpa_supplicant
EOF

# Populate `/etc/dnsmasq.conf`
sudo bash -c 'cat >> /etc/dnsmasq.conf' << EOF

interface=lo,ap@wlan0
no-dhcp-interface=lo,wlan0
bind-interfaces
server=1.1.1.1
domain-needed
bogus-priv
dhcp-range=${AP_IP_BEGIN}.50,${AP_IP_BEGIN}.150,12h
dhcp-option=3,${AP_IP}

address=/soundbox.lan/${AP_IP}
EOF

# Populate `/etc/hostapd/hostapd.conf`
sudo bash -c 'test -f /etc/hostapd/hostapd.conf || cat > /etc/hostapd/hostapd.conf' << EOF
ctrl_interface=/var/run/hostapd
ctrl_interface_group=0
country_code=${COUNTRY:-US}
interface=ap@wlan0
driver=nl80211
ssid=${AP_SSID}
hw_mode=g
channel=11
wmm_enabled=0
macaddr_acl=0
auth_algs=1
wpa=2
$([ $AP_PASSPHRASE ] && echo "wpa_passphrase=${AP_PASSPHRASE}")
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP CCMP
rsn_pairwise=CCMP
EOF

sudo chmod 600 /etc/hostapd/hostapd.conf

sudo bash -c 'SYSTEMD_EDITOR=tee systemctl edit --force --full accesspoint@.service' <<\EOF
[Unit]
Description=IEEE 802.11 ap@%i AP on %i with hostapd
Wants=wpa_supplicant@%i.service

[Service]
Type=forking
PIDFile=/run/hostapd.pid
Restart=on-failure
RestartSec=2
#Environment=DAEMON_CONF=/etc/hostapd/hostapd.conf
EnvironmentFile=-/etc/default/hostapd
ExecStartPre=/sbin/iw dev %i interface add ap@%i type __ap
ExecStart=/usr/sbin/hostapd -i ap@%i -P /run/hostapd.pid -B /etc/hostapd/hostapd.conf
ExecStopPost=-/sbin/iw dev ap@%i del

[Install]
WantedBy=sys-subsystem-net-devices-%i.device
EOF

sudo systemctl stop hostapd # if the default hostapd service was active before
sudo systemctl disable hostapd # if the default hostapd service was enabled before
sudo systemctl enable accesspoint@wlan0.service
sudo rfkill unblock wlan

# Populate `/etc/wpa_supplicant/wpa_supplicant.conf`
sudo bash -c 'test -f /etc/wpa_supplicant/wpa_supplicant.conf || cat > /etc/wpa_supplicant/wpa_supplicant.conf' << EOF
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=${COUNTRY:-US}

network={
    ssid="${CLIENT_SSID}"
    $([ $CLIENT_PASSPHRASE ] && echo "psk=\"${CLIENT_PASSPHRASE}\"")
}
EOF

sudo chmod 600 /etc/wpa_supplicant/wpa_supplicant.conf

# not used, as the agent is hooked by dhcpcd
sudo systemctl disable wpa_supplicant.service

# We can then follow Raspberry’s documentation to enable routing and IP masquerading:
sudo DEBIAN_FRONTEND=noninteractive apt install -y netfilter-persistent iptables-persistent

sudo bash -c 'test -f /etc/sysctl.d/routed-ap.conf || cat >/etc/sysctl.d/routed-ap.conf' <<\EOF
# https://www.raspberrypi.org/documentation/configuration/wireless/access-point-routed.md
# Enable IPv4 routing
net.ipv4.ip_forward=1
EOF

# Add firewall rules
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
sudo iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
sudo iptables -A FORWARD -i wlan0 -o ap@wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i ap@wlan0 -o wlan0 -j ACCEPT
sudo netfilter-persistent save

# persist powermanagement off for wlan0
grep 'iw dev wlan0 set power_save off' /etc/rc.local || sudo sed -i 's:^exit 0:iw dev wlan0 set power_save off\n\nexit 0:' /etc/rc.local

# Finish
echo "Wifi configuration is finished! Please reboot your Raspberry Pi to apply changes..."