The bidirectional forwarders inside create_tls_proxy._handle catch
(ConnectionError, OSError, asyncio.CancelledError) on writes, but
uvloop's UVStream.write raises a plain RuntimeError from
UVHandle._ensure_alive when the underlying handle is already closed.
asyncio's default selector loop reports the same situation as
ConnectionResetError, so the bug only surfaced on uvloop — and only at
the moment ffmpeg (or a snapshot-capture subprocess) dropped its socket
while the proxy was mid-flush.
The RuntimeError slipped past the except tuple, escaped the forwarder
coroutine, and asyncio's client_connected_cb task-exception handler
logged a noisy multi-line traceback ending in:
RuntimeError: unable to perform operation on
<TCPTransport closed=True ...>; the handler is closed
Adds RuntimeError to the except tuple in both _fwd_to_server and
_fwd_to_client (the latter is the actual frame from the bug report —
server→client is where buffered TLS chunks land after the client has
gone). The forwarders are intentionally fire-and-forget on tear-down;
the existing dst.close() in the finally block already handles cleanup.
No functional regression possible — the connection is already dead by
the time the exception fires; this only changes whether asyncio logs an
"Unhandled exception" trace for it.
2 new regression contract tests in test_camera_tls_proxy.py use
inspect.getsource to assert both forwarder closures' except clauses
include RuntimeError. Source-level rather than a runtime test because
the forwarders are nested closures inside _handle and extracting them
just for testability would require a pure-cosmetic refactor.
Latent since 0feed83c (Fix P2S camera TLS compatibility via OpenSSL
proxy, #661, 2026-03-15) — only commit that ever touched these
forwarders.
The Debian ffmpeg package uses GnuTLS, whose hardened defaults reject
TLS renegotiation and legacy ciphers that some Bambu printer firmwares
(notably P2S) rely on — causing RTSP sessions to drop after a few
seconds.
Add a local TLS termination proxy (Python ssl/OpenSSL) that handles
the TLS connection to the printer and exposes a plain RTSP port to
ffmpeg. The proxy rewrites RTSP request-line URLs (rtsp://proxy →
rtsps://printer) while preserving Authorization headers so Digest
auth hashes remain valid.
Also:
- Reduce RTSP reconnect delay from 1.0s to 0.2s
- Add ffmpeg fast-start flags (-probesize 32, -analyzeduration 0,
-fflags nobuffer, -flags low_delay)
- Fix external camera double rate-limiting causing choppy streams
- Apply TLS proxy to external camera rtsps:// URLs and snapshot capture
- Update orphan ffmpeg cleanup to match rtsp:// (proxied) URLs
- Add unit tests for RTSP URL rewriting and proxy lifecycle
maziggy