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83fbcca557
* Clean up direct peer detection logic (Max TTL) and remove unrelated routing/media changes * cleanup fix
113 lines
5.3 KiB
Markdown
113 lines
5.3 KiB
Markdown
# Device Monitoring Manager — Design and Integration
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This change introduces a lean DeviceMonitoringManager to strictly manage BLE device connections while keeping the existing code structure intact.
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## Goals
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- Maintain a blocklist of device MAC addresses to deny incoming/outgoing connections.
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- Drop and block connections that never ANNOUNCE within 15 seconds of establishment.
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- Drop and block connections that go silent (no packets) for over 60 seconds.
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- Block devices that experience 5 error disconnects within a 5-minute window.
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- Auto-unblock devices after 15 minutes.
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## Implementation Overview
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File: `app/src/main/java/com/bitchat/android/mesh/DeviceMonitoringManager.kt`
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- Thread-safe maps with coroutine-based timers.
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- Minimal surface area: a few clearly named entry points to hook into existing flows.
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- Callbacks to perform disconnects without coupling to GATT APIs.
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Key logic:
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- `isBlocked(address)`: check if a MAC is blocked (auto-clears on expiry).
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- `block(address, reason)`: add MAC to blocklist (15m), disconnect via callback, auto-unblock later.
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- `onConnectionEstablished(address)`: start 15s “first ANNOUNCE” timer and a 60s inactivity timer.
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- `onAnnounceReceived(address)`: cancel the 15s ANNOUNCE timer for that device.
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- `onAnyPacketReceived(address)`: refresh 60s inactivity timer.
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- `onDeviceDisconnected(address, status)`: track error disconnects and block on 5 within 5 minutes.
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Timers:
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- ANNOUNCE timer: 15 seconds from connection establishment.
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- Inactivity timer: resets on any packet; fires after 60 seconds of silence.
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- Blocklist TTL: 15 minutes per device (auto-unblock job per entry).
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## Wiring Points (Minimal Changes)
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1) Connection Manager
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- File: `BluetoothConnectionManager.kt`
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- Added a `DeviceMonitoringManager` instance and provided a `disconnectCallback` that:
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- disconnects client GATT connections via `BluetoothConnectionTracker`.
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- cancels server connections via `BluetoothGattServer.cancelConnection`.
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- Updated `componentDelegate.onPacketReceived` to notify per-device activity to the monitor.
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2) GATT Client
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- File: `BluetoothGattClientManager.kt`
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- Constructor now receives `deviceMonitor`.
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- Before attempting any outgoing connection (from scan or direct connect), deny if blocked.
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- On connection setup complete (after CCCD enable), call `deviceMonitor.onConnectionEstablished(addr)`.
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- On incoming packet (`onCharacteristicChanged`), call `deviceMonitor.onAnyPacketReceived(addr)`.
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- On disconnect, call `deviceMonitor.onDeviceDisconnected(addr, status)` to track error bursts.
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3) GATT Server
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- File: `BluetoothGattServerManager.kt`
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- Constructor now receives `deviceMonitor`.
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- On incoming connection, immediately deny (cancelConnection) if blocked, before tracking it.
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- On connection setup complete (descriptor enable) and also after initial connect, start monitoring via `onConnectionEstablished(addr)`.
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- On packet write, call `deviceMonitor.onAnyPacketReceived(addr)`.
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- On disconnect, call `deviceMonitor.onDeviceDisconnected(addr, status)`.
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4) ANNOUNCE Binding
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- File: `BluetoothMeshService.kt` (in the ANNOUNCE handler where we first map device → peer)
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## Behavior Summary
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- Blocked devices:
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- Outgoing: client will not initiate connections.
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- Incoming: server cancels the connection immediately.
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- Existing connection: monitor disconnects instantly and blocks for 15 minutes.
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- No ANNOUNCE within 15s of connection:
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- Connection is dropped and device is blocked for 15 minutes.
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- No packets for >60s:
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- Connection is dropped and device is blocked for 15 minutes.
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- >=5 error disconnects within 5 minutes:
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- Device is blocked for 15 minutes.
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- Auto-unblock:
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- Every block entry automatically expires after 15 minutes.
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## Debug Logging
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- The manager emits chat-visible debug messages through `DebugSettingsManager` (SystemMessage), e.g.:
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- Blocking decisions and reasons
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- Auto-unblock events
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- ANNOUNCE wait start/cancel
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- Inactivity timer set and inactivity-triggered blocks
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- Burst error disconnect threshold reached
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- Additional enforcement logs are added in GATT client/server when a blocked device is denied.
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- Logs appear in the chat when verbose logging is enabled in Debug settings.
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## Panic Triple-Tap
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- Triple-tapping the title now also clears the device blocklist and all device tracking:
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- Calls `BluetoothMeshService.clearAllInternalData()` which triggers `BluetoothConnectionManager.clearDeviceMonitoringAndTracking()`.
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- This disconnects active connections, clears the monitor’s blocklist and timers, and resets the `BluetoothConnectionTracker` state.
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## Notes and Rationale
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- The monitoring manager is intentionally decoupled from GATT specifics via a disconnect callback. This keeps responsibilities separate and avoids plumbing GATT instances through unrelated classes.
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- Packet activity is captured in both client and server data paths as early as possible to ensure the inactivity timer is accurate even before higher-level processing.
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- The “first ANNOUNCE” check uses the same mapping event that sets `addressPeerMap` to avoid false positives on unverified announces.
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## Touched Files
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- Added: `mesh/DeviceMonitoringManager.kt`
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- Updated: `mesh/BluetoothConnectionManager.kt`
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- Updated: `mesh/BluetoothGattClientManager.kt`
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- Updated: `mesh/BluetoothGattServerManager.kt`
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- Updated: `mesh/BluetoothMeshService.kt`
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These changes are small, local, and respect existing structure without broad refactors.
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