mirror of
https://github.com/netbirdio/netbird.git
synced 2026-08-03 13:08:38 -04:00
e970daaf5f
The fake IP manager was only created at route manager construction, from the DNS feature flag fetched by the initial GetNetworkMap call. When the flag flipped to true mid-session, UpdateRoutes set useNewDNSRoute but never created the manager, so domain routes added after the flip got a DNS interceptor with a nil fake IP manager. internalDnatFw only checked for a firewall and GOOS, so the interceptor took the DNAT path and called GetFakeIP/AllocateFakeIP on the nil *fakeip.Manager. These methods lock m.mu first, which is a nil pointer dereference: the first DNS answer for such a route panicked and crashed the VPN service. The fake IP blocks (240.0.0.0/8 and its v6 pair) also never reached the TUN, since only the constructor registered them. Create the manager and its TUN routes from UpdateRoutes when the flag turns on, notify so the fake IP blocks get into the TUN without a client route change, and treat a nil manager as no internal DNAT. This is groundwork for removing the initial GetNetworkMap fetch, after which every startup goes through the flag-off-to-on transition.