setup_hotspot.sh

#!/bin/bash

# Hotspot Setup Script
# This script stops NetworkManager and creates a WiFi hotspot using hostapd and dnsmasq

set -e

# Configuration variables
INTERFACE="wlan0"              # WiFi interface
SSID="LaserUI-Hotspot"         # Network name
PASSWORD="laserui123"          # WPA password (min 8 characters)
CHANNEL="6"                    # WiFi channel
IP_ADDRESS="192.168.50.1"      # Hotspot IP address
NETMASK="255.255.255.0"        # Network mask
DHCP_RANGE_START="192.168.50.10"
DHCP_RANGE_END="192.168.50.50"
DHCP_LEASE_TIME="12h"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Check if running as root
if [ "$EUID" -ne 0 ]; then
    echo -e "${RED}Error: This script must be run as root${NC}"
    echo "Please run: sudo $0"
    exit 1
fi

echo -e "${GREEN}=== WiFi Hotspot Setup ===${NC}"

# Step 1: Stop NetworkManager
echo -e "${YELLOW}[1/7] Stopping NetworkManager...${NC}"
systemctl stop NetworkManager
systemctl disable NetworkManager
echo -e "${GREEN}✓ NetworkManager stopped${NC}"

# Step 2: Bring down the interface
echo -e "${YELLOW}[2/7] Bringing down interface ${INTERFACE}...${NC}"
ip link set $INTERFACE down
sleep 2
echo -e "${GREEN}✓ Interface down${NC}"

# Step 3: Configure the interface
echo -e "${YELLOW}[3/7] Configuring interface ${INTERFACE}...${NC}"
ip addr flush dev $INTERFACE
ip addr add ${IP_ADDRESS}/24 dev $INTERFACE
ip link set $INTERFACE up
echo -e "${GREEN}✓ Interface configured with IP ${IP_ADDRESS}${NC}"

# Step 4: Create hostapd configuration
echo -e "${YELLOW}[4/7] Creating hostapd configuration...${NC}"
cat > /etc/hostapd/hostapd.conf <<EOF
# Interface configuration
interface=$INTERFACE
driver=nl80211

# WiFi configuration
ssid=$SSID
hw_mode=g
channel=$CHANNEL
ieee80211n=1
wmm_enabled=1

# Security configuration
auth_algs=1
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_passphrase=$PASSWORD
rsn_pairwise=CCMP

# Logging
logger_syslog=-1
logger_syslog_level=2
logger_stdout=-1
logger_stdout_level=2
EOF

echo -e "${GREEN}✓ hostapd configuration created${NC}"

# Step 5: Create dnsmasq configuration
echo -e "${YELLOW}[5/7] Creating dnsmasq configuration...${NC}"

# Backup original dnsmasq.conf if it exists
if [ -f /etc/dnsmasq.conf ]; then
    cp /etc/dnsmasq.conf /etc/dnsmasq.conf.backup
fi

cat > /etc/dnsmasq.conf <<EOF
# Interface configuration
interface=$INTERFACE
bind-interfaces

# DHCP configuration
dhcp-range=$DHCP_RANGE_START,$DHCP_RANGE_END,$NETMASK,$DHCP_LEASE_TIME
dhcp-option=3,$IP_ADDRESS     # Default gateway
dhcp-option=6,$IP_ADDRESS     # DNS server

# DNS configuration
server=8.8.8.8
server=8.8.4.4

# Logging
log-queries
log-dhcp
EOF

echo -e "${GREEN}✓ dnsmasq configuration created${NC}"

# Step 6: Enable IP forwarding
echo -e "${YELLOW}[6/7] Enabling IP forwarding...${NC}"
echo 1 > /proc/sys/net/ipv4/ip_forward
# Make it persistent
if ! grep -q "net.ipv4.ip_forward=1" /etc/sysctl.conf; then
    echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
fi
echo -e "${GREEN}✓ IP forwarding enabled${NC}"

# Step 7: Start services
echo -e "${YELLOW}[7/7] Starting hostapd and dnsmasq...${NC}"

# Kill any existing instances
pkill hostapd 2>/dev/null || true
pkill dnsmasq 2>/dev/null || true
sleep 1

# Start hostapd
hostapd /etc/hostapd/hostapd.conf -B
if [ $? -eq 0 ]; then
    echo -e "${GREEN}✓ hostapd started${NC}"
else
    echo -e "${RED}✗ Failed to start hostapd${NC}"
    exit 1
fi

# Start dnsmasq
dnsmasq -C /etc/dnsmasq.conf
if [ $? -eq 0 ]; then
    echo -e "${GREEN}✓ dnsmasq started${NC}"
else
    echo -e "${RED}✗ Failed to start dnsmasq${NC}"
    exit 1
fi

echo ""
echo -e "${GREEN}=== Hotspot Setup Complete ===${NC}"
echo -e "SSID: ${YELLOW}$SSID${NC}"
echo -e "Password: ${YELLOW}$PASSWORD${NC}"
echo -e "Gateway IP: ${YELLOW}$IP_ADDRESS${NC}"
echo ""
echo -e "To stop the hotspot, run: ${YELLOW}sudo ./stop_hotspot.sh${NC}"
echo ""