Sets up a tray icon to connect to the ETHZ VPN

vpn-tray-ubuntu-gnome.sh

#!/bin/bash
set -euo pipefail

LOGIN_NAME="[email protected]"
GENERAL_PASSWORD=''
OTP_SECRET="..."
HOST="sslvpn.ethz.ch"
OPTS=""

export GDK_BACKEND=x11  # Ensure yad works on Wayland

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ICON_CONNECTED="$SCRIPT_DIR/vpn-on.png"
ICON_DISCONNECTED="$SCRIPT_DIR/vpn-off.png"


# Function to check if ETH Zurich VPN is active
is_vpn_active() {
    ip link show tun0 &>/dev/null && ip -4 addr show tun0 | grep -q "inet 10\.5\."
}

# Test external connectivity
is_vpn_reachable() {
    ping -c 1 -W 2 8.8.8.8 &>/dev/null
}


# Start VPN function
start_vpn() {
    echo "Attempting to start VPN..." > /dev/tty
    (echo "$GENERAL_PASSWORD"; oathtool -b --totp "$OTP_SECRET"; sleep 1) | sudo /usr/sbin/openconnect --useragent=AnyConnect -g student-net "$HOST" --passwd-on-stdin -u "$LOGIN_NAME" $OPTS &
    echo "Started openconnect..."
}

# Stop VPN function
stop_vpn() {
    echo "Stopping ETH Zurich VPN..." > /dev/tty
    VPN_PIDS=$(pgrep -f "openconnect .* $HOST") || true

    if [[ -n "$VPN_PIDS" ]]; then
        echo "Stopping OpenConnect processes (PIDs: $VPN_PIDS)..." > /dev/tty
        sudo kill $VPN_PIDS
        wait $VPN_PIDS 2>/dev/null || true
    else
        echo "No active ETH Zurich VPN connection found." > /dev/tty
    fi

    if ip link show tun0 &>/dev/null; then
        echo "Bringing down tun0 interface..." > /dev/tty
        sudo ip link set tun0 down || true
    fi

    echo "VPN Disconnected." > /dev/tty
}

# If script is called with "start" or "stop", handle VPN directly
if [[ $# -gt 0 ]]; then
    case "$1" in
        start) start_vpn; exit 0 ;;
        stop) stop_vpn; exit 0 ;;
        *) echo "Usage: $0 [start|stop]"; exit 1 ;;
    esac
fi

# Ensure yad is installed
if ! command -v yad &>/dev/null; then
    echo "Error: 'yad' is not installed. Install it with: sudo apt install yad"
    exit 1
fi

# Cleanup function to remove tray icon on exit
cleanup() {
    pkill --parent $$ -f "yad --notification" || true
}
trap cleanup EXIT

PREV_STATE=""
CURRENT_STATE="?"

while :; do
    T=`date +%T`
    
    if ! is_vpn_active || ! is_vpn_reachable; then
        echo "VPN status ($T): disconnected."
        ICON=$ICON_DISCONNECTED
        TOOLTIP="VPN Disconnected"
        CURRENT_STATE="disconnected"
        ACTION="start"
    else
        echo "VPN status ($T): connected."
        ICON=$ICON_CONNECTED
        TOOLTIP="VPN Connected (ETH Zurich)"
        CURRENT_STATE="connected"
        ACTION="stop"
    fi


    # Only update the tray icon if the VPN state has changed
    if [[ "$CURRENT_STATE" != "$PREV_STATE" ]]; then
        echo "State changed: Updating tray icon..."

        # Kill only yad instances launched by this script
        pkill --parent $$ -f "yad --notification" || true

        # Clicking the icon toggles VPN state by calling this script with "start" or "stop"
        yad --notification --image="$ICON" --text="$TOOLTIP" --command="bash $0 $ACTION" &
    fi

    PREV_STATE="$CURRENT_STATE"
    sleep 2
done