Wireguard & qBittorrent-nox VPN Tunnel Supervisor

wg_manager.sh

#!/bin/bash
# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! #
# This is hard coded for Chicago servers only #
# !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! #
# Directory containing WireGuard conf files
WG_DIR="/etc/wireguard"
# IP address to ping for connectivity checks
PING_IP="8.8.8.8"
# Time interval between pings (in seconds)
PING_INTERVAL=30
# Number of missed pings before switching servers
MAX_MISSED_PINGS=3
# Log file path
LOG_FILE="/var/log/wg_manager.log"
# Debug mode (1 to enable, 0 to disable)
DEBUG=0
# qBittorrent configuration file
QB_CONF_FILE="/home/qbittorrent-nox/.config/qBittorrent/qBittorrent.conf"
# qBittorrent service name
QB_SERVICE="qbittorrent-nox"

# Function to log messages with timestamps
log() {
    local message="$1"
    local timestamp=$(date +"[%Y-%m-%d %H:%M:%S]")
    echo "$timestamp $message" | tee -a "$LOG_FILE"
}

# Function for debug logging
debug_log() {
    if [ "$DEBUG" -eq 1 ]; then
        local message="$1"
        local timestamp=$(date +"[%Y-%m-%d %H:%M:%S]")
        echo "$timestamp DEBUG: $message" | tee -a "$LOG_FILE"
    fi
}

# Function to generate list of VPN servers from configuration files
generate_vpn_servers() {
    local dir="$1"
    local pattern="$2"
    find "$dir" -type f -name "$pattern" 2>/dev/null | sed "s#.*/##; s/\.conf$//"
}

# Generate the list of available VPN servers
VPN_SERVERS=($(generate_vpn_servers "$WG_DIR" "us-chi-wg-*.conf"))

# Variables to track current VPN connection
current_conf_file=""
current_interface=""

# Function to start a VPN connection
start_vpn() {
    local conf_file="$1"
    local interface=$(basename "$conf_file" .conf)
    
    log "Attempting to start VPN with configuration file: $conf_file"
    
    # Check if the interface already exists and is active
    if ip link show "$interface" &> /dev/null; then
        debug_log "Interface $interface already exists. Bringing it down..."
        stop_vpn "$conf_file"
    fi
    
    # Attempt to bring up the VPN interface
    wg-quick up "$interface"
    local exit_code=$?
    
    if [ "$exit_code" -ne 0 ]; then
        log "Failed to start VPN with configuration file $conf_file. Error code: $exit_code"
        return "$exit_code"
    fi
    
    # Verify that the interface is actually up after wg-quick
    if ip link show "$interface" &> /dev/null; then
        log "VPN connection established successfully using $conf_file."
        current_conf_file="$conf_file"
        current_interface="$interface"
        return 0
    else
        log "VPN interface not found after starting. Configuration: $conf_file"
        return 1
    fi
}

# Function to stop a VPN connection
stop_vpn() {
    local conf_file="$1"
    local interface=$(basename "$conf_file" .conf)
    local exit_code=0
    
    if ip link show "$interface" &> /dev/null; then
        log "Stopping VPN connection: $conf_file"
        wg-quick down "$interface"
        exit_code=$?
        
        if [ "$exit_code" -eq 0 ]; then
            log "VPN connection stopped successfully."
        else
            log "Failed to stop VPN. Error code: $exit_code"
        fi
        
        # Ensure the interface is actually removed
        while ip link show "$interface" &> /dev/null; do
            debug_log "Waiting for interface $interface to be removed..."
            sleep 1
        done
    else
        debug_log "Interface $interface not found. No action needed."
    fi
    
    return "$exit_code"
}

# Function to check internet connectivity by pinging a target
check_connectivity() {
    local ping_ip="$1"
    local missed_pings=0
    local max_missed="$MAX_MISSED_PINGS"
    
    while [ "$missed_pings" -lt "$max_missed" ]; do
        debug_log "Attempting to ping $ping_ip..."
        
        if ping -c 1 "$ping_ip" &> /dev/null; then
            debug_log "Successfully connected to $ping_ip."
            missed_pings=0 # Reset counter on successful ping
            return 0
        else
            log "Connectivity check failed: Cannot reach $ping_ip."
            missed_pings=$((missed_pings + 1))
            debug_log "Missed pings: $missed_pings / $max_missed"
            
            if [ "$missed_pings" -ge "$max_missed" ]; then
                return 1
            fi
            
            sleep "$PING_INTERVAL"
        fi
    done
    
    log "Maximum missed pings ($max_missed) reached. Connectivity lost."
    return 1
}

# Function to update qBittorrent configuration with a new interface
update_qbittorrent_config() {
    local interface="$1"
    
    if [ -z "$interface" ]; then
        log "No interface provided for qBittorrent configuration update."
        return 1
    fi
    
    # Ensure the qBittorrent config file exists and is writable
    if [ ! -f "$QB_CONF_FILE" ]; then
        log "qBittorrent configuration file not found. Creating it..."
        mkdir -p "$(dirname "$QB_CONF_FILE")"
        touch "$QB_CONF_FILE"
    elif [ ! -w "$QB_CONF_FILE" ]; then
        log "qBittorrent configuration file is not writable."
        return 1
    fi
    
    # Update both Session\Interface and Session\InterfaceName settings
    # Using single quotes to avoid bash interpreting the backslash
    sed -i '/^Session\\Interface=/d' "$QB_CONF_FILE"
    echo "Session\\Interface=$interface" >> "$QB_CONF_FILE"
    local exit_code_sed1=$?
    
    sed -i '/^Session\\InterfaceName=/d' "$QB_CONF_FILE"
    echo "Session\\InterfaceName=$interface" >> "$QB_CONF_FILE"
    local exit_code_sed2=$?
    
    if [ "$exit_code_sed1" -eq 0 ] && [ "$exit_code_sed2" -eq 0 ]; then
        log "qBittorrent configuration updated successfully with interface $interface."
        return 0
    else
        log "Failed to update qBittorrent configuration. Error codes: $exit_code_sed1, $exit_code_sed2"
        return 1
    fi
}

# Function to restart the qBittorrent service
restart_qbittorrent() {
    log "Restarting qBittorrent service..."
    
    systemctl restart "$QB_SERVICE"
    local exit_code=$?
    
    if [ "$exit_code" -eq 0 ]; then
        log "qBittorrent service restarted successfully."
        return 0
    else
        log "Failed to restart qBittorrent service. Error code: $exit_code"
        return 1
    fi
}

# Function to get the current interface from qBittorrent config
get_current_qbittorrent_interface() {
    if [ ! -f "$QB_CONF_FILE" ]; then
        log "qBittorrent configuration file not found."
        return 1
    fi
    
    # Using single quotes to avoid shell interpretation of the backslash
    local interface=$(grep '^Session\\Interface=' "$QB_CONF_FILE" | cut -d'=' -f2)
    
    # Check if the line exists and is not empty
    if [ -n "$interface" ]; then
        echo "$interface"
        return 0
    else
        log "qBittorrent configuration does not contain an interface setting."
        return 1
    fi
}

# Function to initialize qBittorrent configuration on script start
initialize_qbittorrent_config() {
    # Get current interface from config if it exists
    local current_interface_in_qbt=""
    if get_current_qbittorrent_interface > /dev/null 2>&1; then
        current_interface_in_qbt=$(get_current_qbittorrent_interface)
    fi
    
    # Check if we have a valid interface from config
    if [ -z "$current_interface_in_qbt" ]; then
        log "No valid interface found in qBittorrent configuration. Initializing..."
        
        # Try each VPN server in order
        for server in "${VPN_SERVERS[@]}"; do
            local conf_file="$WG_DIR/$server.conf"
            
            if [ ! -f "$conf_file" ]; then
                log "Configuration file $conf_file not found."
                continue
            fi
            
            # Try to start the VPN
            start_vpn "$conf_file"
            
            if [ $? -eq 0 ]; then
                log "VPN connection established with $server."
                
                # Verify connectivity
                check_connectivity "$PING_IP"
                
                if [ $? -eq 0 ]; then
                    # Update qBittorrent only if we have a valid interface
                    if [ -n "$current_interface" ]; then
                        update_qbittorrent_config "$current_interface"
                        restart_qbittorrent
                        
                        if [ $? -eq 0 ]; then
                            log "qBittorrent configuration updated and service restarted."
                            return 0
                        else
                            log "Failed to update qBittorrent configuration or restart service."
                        fi
                    else
                        log "No valid interface available for qBittorrent."
                    fi
                else
                    log "VPN connection established but no internet connectivity. Stopping..."
                    stop_vpn "$conf_file"
                fi
            fi
        done
        
        log "No valid VPN servers available for connection."
        return 1
    else
        log "qBittorrent already configured with interface: $current_interface_in_qbt"
        
        # Verify if the recorded interface is currently active
        if [ -n "$current_interface_in_qbt" ] && ip link show "$current_interface_in_qbt" &> /dev/null; then
            log "Interface $current_interface_in_qbt is active."
            current_conf_file=$(find "$WG_DIR" -name "${current_interface_in_qbt}.conf")
            current_interface="$current_interface_in_qbt"
            return 0
        else
            # Don't recursively call, just note that we need to initialize
            log "Configured interface $current_interface_in_qbt is not active. Will initialize in main loop."
            return 1
        fi
    fi
}

# Function to cleanly stop all VPN connections and exit the script
cleanup_and_exit() {
    log "Script cleanup initiated."
    
    # Stop any active VPN connection first
    if [ -n "$current_conf_file" ]; then
        stop_vpn "$current_conf_file"
    fi
    
    # Ensure no other WireGuard interfaces are running
    for server in "${VPN_SERVERS[@]}"; do
        local conf_file="$WG_DIR/$server.conf"
        
        if [ -f "$conf_file" ] && [ "$conf_file" != "$current_conf_file" ]; then
            stop_vpn "$conf_file"
        fi
    done
    
    log "All VPN connections terminated. Script exiting."
    exit 0
}

# Trap to handle SIGINT and SIGTERM signals for cleanup
trap 'cleanup_and_exit' SIGINT SIGTERM

# Main loop to monitor and maintain the VPN connection
main_loop() {
    local last_vpn_server_index=0
    
    while true; do
        # Cycle through each available VPN server
        for ((server_index = 0; server_index < ${#VPN_SERVERS[@]}; server_index++)); do
            local server="${VPN_SERVERS[$server_index]}"
            local conf_file="$WG_DIR/$server.conf"
            
            if [ ! -f "$conf_file" ]; then
                log "Configuration file $conf_file not found. Skipping..."
                continue
            fi
            
            # Attempt to start the VPN connection
            start_vpn "$conf_file"
            
            if [ $? -eq 0 ]; then
                log "VPN connection established with $server."
                
                # Verify connectivity after establishing the VPN
                check_connectivity "$PING_IP"
                
                if [ $? -eq 0 ]; then
                    # Ensure we have a valid interface name
                    if [ -n "$current_interface" ]; then
                        update_qbittorrent_config "$current_interface"
                        restart_qbittorrent
                        
                        if [ $? -eq 0 ]; then
                            log "qBittorrent configuration updated and service restarted."
                        else
                            log "Failed to update qBittorrent configuration or restart service."
                        fi
                    else
                        log "No valid interface available for qBittorrent."
                    fi
                else
                    log "VPN connection established but no internet connectivity. Stopping..."
                    stop_vpn "$conf_file"
                    continue
                fi
                
                # Continuously monitor connectivity
                while true; do
                    check_connectivity "$PING_IP"
                    
                    if [ $? -ne 0 ]; then
                        log "Connectivity lost. Attempting to reconnect..."
                        
                        stop_vpn "$conf_file"
                        
                        # Move to the next VPN server if available
                        if ((server_index < ${#VPN_SERVERS[@]} - 1)); then
                            server_index=$((server_index + 1))
                            continue 2 # Skip to the next server in the loop
                        else
                            log "All servers exhausted. Waiting before retrying..."
                            sleep 60
                            break
                        fi
                    else
                        # Check if qBittorrent config needs updating
                        local qb_interface=""
                        if get_current_qbittorrent_interface > /dev/null 2>&1; then
                            qb_interface=$(get_current_qbittorrent_interface)
                            
                            if [ "$qb_interface" != "$current_interface" ]; then
                                log "qBittorrent interface ($qb_interface) differs from current VPN interface ($current_interface). Updating..."
                                update_qbittorrent_config "$current_interface"
                                restart_qbittorrent
                            fi
                        else
                            log "No interface found in qBittorrent config. Updating with current interface: $current_interface"
                            update_qbittorrent_config "$current_interface"
                            restart_qbittorrent
                        fi
                        
                        sleep "$PING_INTERVAL"
                    fi
                done
            else
                log "Failed to start VPN with server $server. Error code: $?"
            fi
        done
        
        # If all servers have been tried, wait before retrying
        log "All VPN servers attempted. Waiting before next attempt..."
        sleep 60
    done
}

# Ensure the qBittorrent configuration file exists and is writable
if [ ! -f "$QB_CONF_FILE" ]; then
    log "qBittorrent configuration file not found. Creating it..."
    mkdir -p "$(dirname "$QB_CONF_FILE")"
    touch "$QB_CONF_FILE"
elif [ ! -w "$QB_CONF_FILE" ]; then
    log "qBittorrent configuration file is not writable."
    exit 1
fi

# Initialize qBittorrent configuration
if ! initialize_qbittorrent_config; then
    log "Failed to initialize qBittorrent configuration. Will attempt in main loop."
fi

# Start the main loop
main_loop