Laurence ee27bf3153 Fix race condition in WireGuard session management ...

The race condition existed because while sync.Map is thread-safe for map
operations (Load, Store, Delete, Range), it does not provide thread-safety
for the data stored within it. When WireGuardSession structs were stored as
pointers in the sync.Map, multiple goroutines could:

1. Retrieve the same session pointer from the map concurrently
2. Access and modify the session's fields (particularly LastSeen) without
   synchronization
3. Cause data races when one goroutine reads LastSeen while another updates it

This fix adds a sync.RWMutex to each WireGuardSession struct to protect
concurrent access to its fields. All field access now goes through
thread-safe methods that properly acquire/release the mutex.

Changes:
- Added sync.RWMutex to WireGuardSession struct
- Added thread-safe accessor methods (GetLastSeen, GetDestAddr, etc.)
- Added atomic CheckAndUpdateIfMatch method for efficient check-and-update
- Updated all session field accesses to use thread-safe methods
- Removed redundant Store call after updating LastSeen (pointer update is
  atomic in Go, but field access within pointer was not)

2025-11-13 06:26:09 +00:00

..

relay.go

Fix race condition in WireGuard session management

2025-11-13 06:26:09 +00:00