vpn.sh

#!/bin/bash
# VPN connect script - fixes stale connections after WiFi change
# Usage: ./vpn.sh
# Please change OVPN_CONFIG and VPN_PASS

OVPN_CONFIG="./client.ovpn"
OVPN_DIR="$(dirname "$OVPN_CONFIG")"
VPN_PASS="YOUR_VPN_PASSWORD_HERE"

# --- Require sudo upfront and keep it alive ---
sudo -v || { echo "sudo required"; exit 1; }

echo "==> Killing existing OpenVPN processes..."
sudo killall -q openvpn 2>/dev/null
sleep 1
# Force kill if still alive
sudo killall -9 -q openvpn 2>/dev/null

echo "==> Cleaning up stale tun interfaces..."
for tun in $(ip -o link show type tun 2>/dev/null | awk -F: '{print $2}' | tr -d ' '); do
    sudo ip link set "$tun" down 2>/dev/null
    sudo ip link delete "$tun" 2>/dev/null
done

echo "==> Flushing routes and DNS cache..."
sudo ip route flush cache 2>/dev/null
sudo resolvectl flush-caches 2>/dev/null

echo "==> Restarting network services..."
sudo systemctl restart systemd-resolved
sudo nmcli networking off
sleep 1
sudo nmcli networking on

# Wait for WiFi to reconnect
echo "==> Waiting for network..."
for i in $(seq 1 15); do
    if nmcli -t -f STATE general 2>/dev/null | grep -q "connected"; then
        echo "    Network ready."
        break
    fi
    sleep 1
done

# Verify DNS works before connecting
echo "==> Verifying DNS resolution..."
for i in $(seq 1 5); do
    if host mandara-vpn.naist.jp >/dev/null 2>&1; then
        echo "    DNS OK."
        break
    fi
    if [ "$i" -eq 5 ]; then
        echo "    WARNING: DNS not resolving, trying anyway..."
    fi
    sleep 1
done

echo "==> Connecting to VPN..."
cd "$OVPN_DIR"
echo "$VPN_PASS" | sudo openvpn --config "$OVPN_CONFIG" --askpass /dev/stdin