The reader loop exited silently on any socket error, leaving conn/sock
set so the session still looked open. Every later get()/post()/ping()
then waited out its full request timeout on a session nobody was
reading, raising SessionTimeoutError on repeat, forever.
This started biting in v0.1.3 (d677c72), which moved to connected UDP
sockets: a connected socket surfaces ICMP errors on recv, so one
ECONNREFUSED from a rebooting appliance now killed the reader.
- Advisory ICMP errnos (ECONNREFUSED/EHOSTUNREACH/...) no longer kill
the reader; the next datagram usually works.
- Real reader exits log at WARNING; close()-driven exits stay quiet.
- A _reader_running Event lets get/post/ping/subscribe/refresh_observes
fail fast via _check_live() with SessionClosedError instead of waiting
out a timeout. Callers that never start a reader are unaffected.
Refs QuiteYellow/SmartThings-Local#37
A stateless-by-default DTLS ClientHello probe that classifies a host:port
as DEAD/LIVE/COMPLETED/REJECTED in ~1 RTT off the server's first flight,
sitting in front of the full handshake.
Probe (smartthings_local/protocol/dtls_probe.py):
- Stateless liveness mode (default): stops at HelloVerifyRequest and never
sends the cookie'd second ClientHello, so by RFC 6347 §4.2.1 it leaves
no association on the device — safe to run before a real connect.
- Diagnostic mode (stateless=False): drives the handshake further to
capture cipher/cert-chain/CertificateRequest or a fatal Alert, for
OCF-PKI-wall characterization (#16). Kept out of hot reconnect paths.
- Retransmit + retries: services OpenSSL's DTLS retransmit timer so a
single dropped ClientHello no longer reads as a false DEAD.
MQTT bridge (mqtt_demo):
- Stateless pre-flight gate in session_once() rejects a silent/rebooting
device or wrong port in ~3s (retries=1) instead of eating the 12s
HANDSHAKE_TIMEOUT_S per reconnect.
- OCF-band port autodiscovery when OCF_PORT is unset: races the band in
parallel and returns on the first port to answer LIVE (~1 RTT, abandoning
the dead-port probes), cached across reconnects; the stateless gate
leaves no orphan, preserving the fixed-source-port §4.2.8 invariant.
Validated on real hardware (dryer 49155 / oven 49154): parallel discovery
resolves both ports in <1s, connect with no orphan cooldown, and a wrong
pinned port rejected in ~3s.
Tests: probe behaviour (retransmit recovery, stateless single-flight
guard, silent-port flight budget, diagnostic continuation) and bridge
port-resolution (pinned gate, parallel discovery early-exit, cache).
Root-cause fix for the stale-session stall on always-on appliances (#14).
When the client dies without close_notify (crash, SIGKILL), the device
keeps an orphaned DTLS association keyed to the old 5-tuple; a reconnect
from a fresh ephemeral port presents as a brand-new peer, so the orphan
lingers until the device's own timer reaps it (observed 5-15 min).
RFC 6347 §4.2.8 covers exactly this: a ClientHello arriving on an existing
association's 5-tuple means the peer rebooted, and the server must complete
the new handshake and discard the old association. Add an optional
local_port to DtlsCoapSession that binds the UDP source port, and have the
bridge bind base+appliance-index, so every reconnect re-handshakes over the
same 5-tuple and the orphan is evicted instead of waited out.
Bench-verified on live hardware (2026-07-26): RT-OCF accepts the
same-5-tuple rehandshake (oven, dryer: handshake completes over a
crash-orphaned association, reads work immediately). The oven does not
reproduce the fridge stall even with 11 crash-orphaned OBSERVE
registrations, so fridge-side confirmation of the eviction is still needed.
Co-authored-by: vmvarga <garrysuchiy@gmail.com>
localthings mints its client cert at runtime through the HA config flow
and never writes it to disk. DtlsCoapSession only accepted cert_path/
key_path (file-based), which would have forced localthings to write its
in-memory cert/key to disk on every connect just to migrate off its
vendored copy of this transport layer.
Adds an alternate cert_pem/key_pem constructor path (ported from
localthings' own _load_pem_chain), validated so exactly one cert source
(file pair or PEM pair) is required. Existing file-path callers
(mqtt_demo, setup_cert.py) are unaffected — verified against both real
appliances with each constructor path.
Nest the two library packages under a single import namespace so they
can ship as one distribution:
protocol/ -> smartthings_local/protocol/
ocf/ -> smartthings_local/ocf/ (git mv, history preserved)
- Rewrite all imports protocol.* -> smartthings_local.protocol.*,
ocf.* -> smartthings_local.ocf.* across the ocf modules, mqtt_demo/
(bridge, descriptor, samples), and tests.
- Add pyproject.toml: dist name `smartthings-local`, hatch-vcs versioning
from v* tags, wheel ships only smartthings_local/.
- Add .github/workflows/publish.yml: build + PyPI Trusted Publishing on
v* tags (OIDC, no stored token).
- Force-include protocol/ocf_root_ca.pem via [tool.hatch.build] artifacts:
it is tracked but matches .gitignore's *.pem, so hatchling's VCS file
selection would drop it — and dtls_session.py loads it at runtime.
- Update mqtt_demo Dockerfile COPY and deploy.sh tar allowlist to the
single smartthings_local/ package.
- .gitignore: build artifacts (_version.py, dist/, *.egg-info/).
Validated: pytest tests/ (11 passed), python -m build produces sdist +
wheel with the pem bundled, fresh pip install resolves all nested imports
with the pem readable from site-packages.
Jason Morcos