Initial commit: DHCP whitelist service for direct link connections

Features:
- Docker-based DHCP server with MAC address whitelisting
- Binds to specific ethernet interface only
- NO DNS/gateway advertised (direct link only, not a router)
- Configurable network parameters (subnet, DHCP range, lease times)
- Systemd service integration for Arch/Manjaro
- Test environment with isolated network (172.20.0.0/24)
- Auto-configuration script to detect network settings
- Complete Makefile with management targets

Security:
- Only responds to whitelisted MAC addresses
- deny unknown-clients configuration
- Runs in Docker container for isolation

Configuration:
- Copy .example files to create your config
- interface.conf: Network interface to bind to
- whitelist.conf: Allowed MAC addresses
- network.conf: Network parameters (optional)

scripts/install-service.sh

@@ -0,0 +1,134 @@
+#!/bin/bash
+set -e
+
+# Check if running as root
+if [ "$EUID" -ne 0 ]; then
+    echo "This script must be run with sudo"
+    echo "Usage: sudo make install"
+    exit 1
+fi
+
+SERVICE_NAME="dhcp-whitelist"
+SERVICE_FILE="systemd/${SERVICE_NAME}.service"
+SYSTEMD_DIR="/etc/systemd/system"
+CONFIG_DIR="/etc/dhcp-whitelist"
+PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+echo "=== Installing DHCP Whitelist Service ==="
+echo
+
+# Check if Docker is installed
+if ! command -v docker &> /dev/null; then
+    echo "Error: Docker is not installed"
+    echo "Please install Docker first"
+    exit 1
+fi
+
+# Check if docker-compose is installed
+if ! command -v docker-compose &> /dev/null; then
+    echo "Error: docker-compose is not installed"
+    echo "Please install docker-compose first"
+    exit 1
+fi
+
+# Create config directory
+echo "Creating configuration directory: ${CONFIG_DIR}"
+mkdir -p "${CONFIG_DIR}"
+
+# Copy configuration files
+echo "Copying configuration files..."
+if [ -f "${PROJECT_DIR}/config/interface.conf" ]; then
+    cp "${PROJECT_DIR}/config/interface.conf" "${CONFIG_DIR}/"
+    echo "  Copied interface.conf"
+else
+    echo "Warning: config/interface.conf not found"
+    echo "  Creating default interface.conf"
+    echo "enp0s13f0u3" > "${CONFIG_DIR}/interface.conf"
+fi
+
+if [ -f "${PROJECT_DIR}/config/whitelist.conf" ]; then
+    cp "${PROJECT_DIR}/config/whitelist.conf" "${CONFIG_DIR}/"
+    echo "  Copied whitelist.conf"
+else
+    echo "Warning: config/whitelist.conf not found"
+    echo "  Creating empty whitelist.conf"
+    touch "${CONFIG_DIR}/whitelist.conf"
+fi
+
+# Set proper permissions
+chmod 644 "${CONFIG_DIR}"/*.conf
+echo "Configuration files installed to: ${CONFIG_DIR}"
+
+# Create service file from template
+echo
+echo "Creating systemd service file..."
+cat > "${SYSTEMD_DIR}/${SERVICE_NAME}.service" << EOF
+[Unit]
+Description=DHCP Whitelist Service
+After=network.target docker.service
+Requires=docker.service
+
+[Service]
+Type=simple
+Restart=always
+RestartSec=10
+WorkingDirectory=${PROJECT_DIR}
+Environment="CONFIG_DIR=${CONFIG_DIR}"
+
+# Pre-start: Build the image
+ExecStartPre=/usr/bin/docker-compose build
+
+# Start the service
+ExecStart=/usr/bin/docker-compose up
+
+# Stop the service
+ExecStop=/usr/bin/docker-compose down
+
+# Reload config by restarting containers
+ExecReload=/usr/bin/docker-compose restart
+
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+echo "Service file created: ${SYSTEMD_DIR}/${SERVICE_NAME}.service"
+
+# Create docker-compose override for service mode
+echo
+echo "Creating docker-compose override for service mode..."
+cat > "${PROJECT_DIR}/docker-compose.override.yml" << EOF
+version: '3.8'
+
+services:
+  dhcp-server:
+    volumes:
+      - ${CONFIG_DIR}:/config:ro
+EOF
+
+# Reload systemd
+echo
+echo "Reloading systemd daemon..."
+systemctl daemon-reload
+
+echo
+echo "=== Installation Complete ==="
+echo
+echo "Configuration files location: ${CONFIG_DIR}"
+echo "  - ${CONFIG_DIR}/interface.conf"
+echo "  - ${CONFIG_DIR}/whitelist.conf"
+echo
+echo "Service management commands:"
+echo "  Start service:   systemctl start ${SERVICE_NAME}"
+echo "  Stop service:    systemctl stop ${SERVICE_NAME}"
+echo "  Enable on boot:  systemctl enable ${SERVICE_NAME}"
+echo "  Check status:    systemctl status ${SERVICE_NAME}"
+echo "  View logs:       journalctl -u ${SERVICE_NAME} -f"
+echo
+echo "Or use make targets:"
+echo "  make service_up   - Enable and start service"
+echo "  make service_down - Stop and disable service"
+echo
+echo "To start the service now, run: make service_up"