enricobuehler
290d760ea4
Phase 0 of mid-session shard-payload renegotiation (planning design/shard-payload-reneg.md), stacked on the leg-1 MTU resilience. All three legs are client-side and forward-compatible: deployed clients that carry them accept a mid-session shard change the moment a future host sends one, and nothing changes on the wire until then. - W0.1 — the reassembler's strict shard_bytes firewall becomes per-frame pinning: a frame's first-arriving packet pins that frame's shard size (bounds-checked to [min_shard_bytes, max_shard_bytes], even), later packets must match the pin, and the per-frame block ceiling derives from the pinned size (a session-level cap would reject legitimate post-shrink frames). The reorder race between an ordered control message and unordered video dies structurally: old-geometry frames in flight complete under their own pin while new frames arrive under the new one, and no cross-geometry splice can land in one buffer. The in-flight budget stays byte-based and exact. - W0.2 — MAX_DATAGRAM_BYTES 2048 → 9216: every receive path (transport RECV_BUF, the recvmmsg ring) now accepts sealed jumbo datagrams (9000-MTU LAN ≈ 8908-byte shards). Static buffers over resize-on-ack: the ring delta is 128 × ~7 KiB ≈ 896 KiB per client session, lazily allocated, hosts unaffected. Grep verdict: no embedder uses the constant directly, so no C ABI bump — the regenerated header rides along (drift gate). - W0.3 — trailing Hello field max_shard_payload: u16 (0/absent = legacy), the append-with-placeholder discipline of video_caps/ client_caps. One field is both the renegotiation capability flag and the jumbo ceiling; core's pump advertises it for all client families, the probe too. - Host seam for Phase 1, dead until wired: Packetizer::set_shard_payload (re-derives the block ceilings; construction delegates to it) + Session::set_shard_payload (host-only, Config::validate parity). Verification (the 0.23.0 lesson — geometry changes breed sizing bugs): the slice-wire suite re-runs at shard 512/1216/1408/8908 (exact-multiple sweep, lossy + reversed roundtrips, sentinel path, in-flight budget); mid-stream shrink→grow→revert delivery; the old-geometry reorder race; cross-geometry splice rejection; firewall bounds non-vacuous both ways; a 48-case mixed-geometry reorder-torture proptest asserting per-frame byte-identical DELIVERY and an exactly-zero final budget; and a sealed loopback session test (continuous crypto/replay) delivering frames across live re-keys — every test asserts delivered frames, never the absence of errors. core: 294/294 --features quic + clippy -D warnings (macOS), fmt.
punktfunk — probe (reference client)
punktfunk-probe is the headless reference client for the punktfunk/1 protocol — a
command-line tool for testing, latency measurement, and validating host behavior. It's not a
streaming app you'd watch on; it connects, exercises a plane, and reports numbers. If you want to
actually stream, use the Linux, Windows,
Apple, or Android clients.
Because it links the same punktfunk-core as every other client, it's also the canonical
example of driving the protocol end to end: QUIC control plane, UDP data plane, and the side planes
(input, audio, rumble) over QUIC datagrams.
What it does
- Receives a real stream, writes a playable elementary stream (
.h265/.h264/.av1— the extension tracks the negotiated codec; the probe advertises all three and the host picks), and reports per-frame capture→received latency percentiles (the host stamps each frame with its capture clock). - Verification mode against a synthetic host — byte-checks deterministic test frames.
- Exercises every plane with scripted test traffic:
--input-test(mouse/keyboard),--mic-test(a 440 Hz Opus tone up to the host mic),--touch-test(a synthetic finger),--rich-input-test(DualSense touchpad + motion, logging the HID-output feedback that comes back). - Trust —
--pin <64-hex>pins the host fingerprint;--pair <PIN>runs the SPAKE2 pairing ceremony and prints the verified fingerprint to pin from then on. Without a pin it trusts on first use. - Discovery —
--discover [secs]browses the LAN for_punktfunk._udphosts and prints each (name, addr:port, pairing requirement, cert fingerprint), then exits. - Negotiation knobs —
--mode WxHxFPS,--remode(mid-stream mode change),--bitrate,--codec auto|h264|hevc|av1(preference; the host resolves),--audio-channels(stereo / 5.1 / 7.1),--compositor,--gamepad,--launch,--speed-test. Env:PUNKTFUNK_CLIENT_10BIT=1/PUNKTFUNK_CLIENT_444=1advertise the 10-bit / 4:4:4 client caps (for testing a host'sPUNKTFUNK_10BIT/PUNKTFUNK_444).
Usage
# stream 720p120 from a host, save the video, and print latency percentiles:
cargo run -p punktfunk-probe -- --mode 1280x720x120 --connect HOST:PORT --out /tmp/a.h265
# list hosts on the LAN:
cargo run -p punktfunk-probe -- --discover
# pair with a host that requires it (read the PIN off the host), then stream:
cargo run -p punktfunk-probe -- --connect HOST:PORT --pair 1234
cargo run -p punktfunk-probe -- --connect HOST:PORT --pin <64-hex> --input-test
Full flag reference is in the module doc-comment at the top of src/main.rs.
Related
- Project README — the host, the streaming clients, and the protocol
punktfunk-host punktfunk1-host— the persistent native-protocol listener to probe against (see the "Running on this box" section of the repo README /CLAUDE.md)