mirror of
https://github.com/GNS3/gns3-server.git
synced 2026-08-27 20:40:13 +03:00
350f2b24e7
PortManager.get_free_udp_port had an unguarded find-then-add sequence. A link allocates both ends concurrently (asyncio.gather in UDPLink._prepare -> two POST /ports/udp) and FastAPI runs the sync route handler in a threadpool, so both threads could probe the same 'free' port before either recorded it — handing lport == rport to both ends. uBridge sets SO_REUSEADDR on UDP NIO sockets, so the double bind succeeds silently and the kernel delivers everything to the last-bound socket: one node starves, the other echoes to itself. Make every TCP/UDP allocate/reserve/release path atomic with an RLock, and rebuild _link_data in UDPLink._prepare so reset() commits the fresh port pair instead of re-sending the stale, already-released one. Regression tests: threaded barrier allocation never returns duplicates (red on the old code, UDP and TCP); reset() leaves exactly one mirrored NIO pair per side with lport != rport (red on the old code).