setup_hotspot.sh

#!/bin/bash

# Ensure the script is run as root
if [ "$(id -u)" -ne 0 ]; then
  echo "Please run as root or with sudo."
  exit 1
fi

# Ensure that you have Nala installed
sudo apt install nala
clear

# Update and install required packages using nala
echo "Updating system and installing necessary packages..."
nala update
nala install -y hostapd dnsmasq

# Stop services while configuring
systemctl stop hostapd
systemctl stop dnsmasq

# Backup and configure dnsmasq
echo "Configuring dnsmasq..."
mv /etc/dnsmasq.conf /etc/dnsmasq.conf.orig
cat <<EOF > /etc/dnsmasq.conf
interface=wlan0
dhcp-range=192.168.4.2,192.168.4.20,255.255.255.0,24h
EOF

# Configure hostapd
echo "Configuring hostapd..."
cat <<EOF > /etc/hostapd/hostapd.conf
interface=wlan0
driver=nl80211
ssid=My_RPi3_Hotspot
hw_mode=g
channel=7
ieee80211n=1
wmm_enabled=1
ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40]
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=YourSecurePassword
wpa_key_mgmt=WPA-PSK
rsn_pairwise=CCMP
EOF

# Link hostapd config
sed -i 's|#DAEMON_CONF="|DAEMON_CONF="/etc/hostapd/hostapd.conf|' /etc/default/hostapd

# Configure static IP and disable wpa_supplicant for wlan0
echo "Configuring static IP and disabling wpa_supplicant for wlan0..."
cat <<EOF >> /etc/dhcpcd.conf
interface wlan0
    static ip_address=192.168.4.1/24
    nohook wpa_supplicant
EOF

# Enable IP forwarding
echo "Enabling IP forwarding..."
sed -i 's|#net.ipv4.ip_forward=1|net.ipv4.ip_forward=1|' /etc/sysctl.conf
sysctl -p

# Configure NAT with iptables
echo "Configuring NAT with iptables..."
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A FORWARD -i eth0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i wlan0 -o eth0 -j ACCEPT

# Save iptables rules
sh -c "iptables-save > /etc/iptables.ipv4.nat"

# Ensure iptables rules are applied on boot
echo "Restoring iptables rules on boot..."
sed -i '/^exit 0/i iptables-restore < /etc/iptables.ipv4.nat' /etc/rc.local

# Start and enable services
echo "Starting and enabling hostapd and dnsmasq..."
sudo systemctl unmask hostapd
sudo systemctl enable hostapd
sudo systemctl start hostapd
systemctl start hostapd
systemctl start dnsmasq
systemctl enable hostapd
systemctl enable dnsmasq

# Reboot to apply all changes
echo "Setup complete."
echo "If the Setup was successful without errors, reboot your Raspberry Pi...."