Two related improvements for the audio-rooms moq-lite path on mobile.
** RFC 9114 §6.2.1 + RFC 9204 §4.2 critical-stream closure **
When the peer closes a critical unidirectional stream — control (0x00),
QPACK encoder (0x02), or QPACK decoder (0x03) — the spec MANDATES we
treat it as a connection error of type H3_CLOSED_CRITICAL_STREAM.
Pre-fix the demux only set `peerH3ProtocolError` flag on protocol
violations, with no autonomous close on clean FIN; the application
was expected to poll. For audio rooms running on lossy mobile paths,
relay-side control-stream drops left users staring at silent audio.
* `Http3ErrorCode` constants for the §8.1 error-code table.
* `WtPeerStreamDemux.drainControlStream` calls `connection.close(...)`
on either clean FIN (H3_CLOSED_CRITICAL_STREAM) or QuicCodecException
raised by the frame reader (specific code via
[http3ErrorCodeForMessage] map: H3_MISSING_SETTINGS,
H3_FRAME_UNEXPECTED, H3_SETTINGS_ERROR, H3_ID_ERROR, etc.).
* New `drainCriticalStream` helper fires the same close on QPACK
encoder / decoder FIN (RFC 9204 §4.2).
* Closure intent latched on `criticalStreamClosureCode` /
`criticalStreamClosureReason` so tests can verify the path runs
without wiring a real driver.
** RFC 9000 §10.3 stateless-reset tokens for migrated CIDs **
The 2026-05-09 stateless-reset detection covered tokens in the
unused-CID pool but lost them the moment a CID was rotated to active
via `tryStartValidation` (WiFi handoff) or `forceRotateToHigherSequence`
(peer-forced retire). On the new path the migrated token wouldn't
match — relay crash mid-handoff would silently hang until idle timeout.
* `PathValidator.knownStatelessResetTokens` — append-only lifetime
store, populated in `recordPeerNewConnectionId`. Survives rotation.
* `QuicConnection.isStatelessReset` walks the lifetime store instead
of the unused pool.
* §10.3.1 explicitly permits keeping tokens after retirement; cost
is ~16 bytes per peer-issued CID.
Tests:
* `CriticalStreamClosureTest` (5 cases) — control FIN, QPACK FIN,
MISSING_SETTINGS, FRAME_UNEXPECTED, idempotency.
* `StatelessResetDetectionTest` extended with 2 cases —
`token_persists_after_path_migration_for_wifi_handoff` and
`token_persists_through_force_rotation_for_acid_reissue`.
Plan updated: 🟦 H3_CLOSED_CRITICAL_STREAM resolved; the
"limitation: tokens for actively-used DCIDs we migrated to" caveat is
removed from the §10.3 entry and from known-limitations item #5.
https://claude.ai/code/session_01XGmmaVuy2wsSZQx2AqN2ik
Claude
cdb9d87a2e