DNS VPN Autotoggle

Stock Android Fix: VPN + Private DNS in Android is broken. This auto-disables Private DNS on connect → restores on disconnect. EvolutionX is one outlier that has a built-in toggle, but not everyone wants to install custom ROMS.

DNS VPN Autotoggle automates this common headache:

VPN connects → Private DNS STAYS ON → DNS conflicts, leaks, no internet Manual fix: Settings → Network → Private DNS → Off → VPN works VPN disconnects → Forget to re-enable → Lose DNS protection

This simple module makes that headache go away, automatically!

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Features

• Automatically detects VPN interfaces (tun*, ppp*, wg*, clat0, vnic*, ep*, `vep*').
• When VPN connects:
  • Remembers your current private_dns_mode and, if applicable, private_dns_specifier.
  • Sets Private DNS off to avoid conflicts or leaks.
• When VPN disconnects:
  • Restores the previous mode exactly (e.g. hostname, opportunistic, etc.).
  • Restores the previous hostname/specifier (e.g. your NextDNS DoT domain) when appropriate.
• Pauses polling when all networks are disabled or airplane mode is on.
• Robust error logging to /data/adb/modules/dns-vpn-autotoggle/service.log.
• No UI required; respects whatever you configured in Android’s Private DNS settings.

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Requirements

• Root: Magisk 24+ or KernelSU
• Android: 9 (Pie) or newer (Private DNS introduced in Android 9).

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Installation

1. Download or build the module ZIP:

   • Clone repo:

     git clone https://github.com/ceryneian775/dns-vpn-autotoggle.git
     cd dns-vpn-autotoggle
     zip -r ../dns-vpn-autotoggle-install.zip *
     

2. In Magisk Manager:

   • Go to Modules → Install from storage.
   • Select dns-vpn-autotoggle-install.zip.
   • Reboot.

3. (Optional but recommended) In Android:

   • Go to Settings → Network & Internet → Private DNS.
   • Set your preferred DoT provider hostname (e.g. NextDNS).
   • The module will toggle between Off and your existing setting automatically.

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How It Works

• A Magisk service.sh runs as a late_start service on boot.
• It:
  • Checks if any known VPN interface is UP via ip link.
  • Reads/writes Settings.Global.private_dns_mode and private_dns_specifier using settings as root.
  • Logs decisions and errors to:
    • /data/adb/modules/dns-vpn-autotoggle/service.log

The script is designed to be conservative:

• It only changes Private DNS when VPN state transitions (connect/disconnect).
• It does not overwrite your hostname or mode outside those transitions.

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Logging & Debugging

• Log file:
  /data/adb/modules/dns-vpn-autotoggle/service.log

If toggling does not work, check for:

• Permission/SELinux errors around the settings command.
• VPN interface names not covered in the default list (add them in service.sh if needed).

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Uninstall

• Use Magisk Manager → Modules → Remove and reboot.
• No system files are patched; all changes are limited to the module directory and runtime settings.

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License

This project is licensed under the GPL-2.0. See LICENSE for details.