mirror of
https://github.com/coturn/coturn.git
synced 2026-10-24 00:08:57 +03:00
ce8b25737d
Historically a MOBILITY-TICKET resume hard-switched the allocation onto the new client socket at REFRESH time and closed the old socket immediately. RFC 8016 instead requires the server to keep receiving on, and transmitting peer->client data to, the old 5-tuple until the client is active on the new one, and only then discard the old 5-tuple. Implement that make-before-break handoff: - handle_turn_refresh no longer transfers the socket. It rotates the mobility ticket, refreshes the allocation on the original session, and opens a bounded transition: the original session keeps the allocation and its old socket (peer->client egress stays on the old 5-tuple), while the resuming session is kept alive and linked as "pending" and the REFRESH success response is sent on the new socket. - read_client_connection promotes the allocation onto the new socket on the client's first packet from the new 5-tuple (mobile_complete_transition): the socket is moved to the allocation session, which closes the old socket and discards the old 5-tuple, and the packet is then served by the allocation. RFC names the trigger as the first Send/ChannelData; we promote on any first packet so control requests (CreatePermission/ChannelBind/Refresh) a roaming client issues from the new address are served by the allocation. - The per-session sweep aborts a transition left open past a 30s deadline, conservatively keeping the allocation on the old path and reaping the pending session. shutdown_client_connection unlinks a transition partner on teardown. Transition state (session ids + deadline) is added to ts_ur_super_session; the pending session's un-allocated watchdog is disarmed and its stray mobile-map entry removed while it legitimately holds no allocation. Also align resume error codes with RFC 8016: an unusable/unknown ticket now returns 437 (Allocation Mismatch) instead of the non-standard 404. examples/run_tests_mobile.sh now asserts, from the server log, that the handoff actually executed (mobile_complete_transition emits a marker), so a regression that skipped or broke the transition fails the test. docs/mobility-rfc8016.md documents the design, the trigger/deadline semantics, the quota note, and the deferred ticket-entropy hardening item.