enricobuehlerandClaude Fable 5
abe6228b42
The VK key-event vocabulary cannot express text an input method COMMITS (autocorrect, gesture typing, non-Latin scripts, emoji). Add a first-class text event and negotiate it: - punktfunk-core: InputKind::TextInput (= 15) carries one Unicode scalar per event in `code`; HOST_CAP_TEXT_INPUT (0x04) in Welcome::host_caps. - Host advertises the cap only where the session's inject backend can type text: Windows SendInput (KEYEVENTF_UNICODE, surrogate-pair aware) and the Linux wlroots backend — a dedicated second zwp_virtual_keyboard whose xkb keymap grows Unicode keysyms on demand (the wtype model), so keymap re-uploads never disturb the main device's layout/modifier state. The KWin-fake-input/libei/gamescope backends can only press layout keycodes, so those sessions don't set the bit and clients keep the VK fallback. - GameStream plane: Moonlight's UTF-8 text packet (MAGIC_UTF8, previously recognized-and-dropped) now decodes to the same TextInput events. - Android: KeyCaptureView picks a real editable InputConnection when the host has the cap — the IME runs its full machinery, mirrored to the host live via common-prefix diffs of the composition (backspaces + new suffix), with setComposingRegion adopting committed text so autocorrect-revert flows diff instead of retyping; newline→Enter, deleteSurroundingText→Backspace/Delete. Older hosts keep the TYPE_NULL raw-key path unchanged. - keymap: media VKs (0xB0-0xB3) → evdev so the Android media keys land on Linux hosts too. Verified: punktfunk-core + host gamestream + pf-inject tests green on Linux (Ubuntu box), clippy clean; Android app+native builds. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
punktfunk-core
The shared protocol core — the one place where punktfunk's transport, forward error correction, and crypto live. It's linked into the host and every native client, so there's exactly one implementation of the wire format everywhere.
Written in Rust with no async on the per-frame path (native threads only). It exposes both a normal Rust API and a stable, versioned C ABI, so the Swift and Kotlin clients — and any C embedder — link the same code as the Rust ones.
What's in here
- Transport & session (
session.rs,transport/,packet.rs) — thepunktfunk/1data plane over raw UDP: packetization, reassembly (with attacker-bounded limits), pacing, and socket tuning. - FEC (
fec/) — the wall-breaker. Two codes:- GF(2⁸) classic Reed–Solomon with the Cauchy generator matrix — byte-identical to the
nanorslibrary Moonlight uses, so our parity is decodable by a stock Moonlight client. - GF(2¹⁶) Leopard-RS (SIMD, O(n log n)) — up to 65535 shards/block, which removes the ~1 Gbps
FEC ceiling.
punktfunk/1negotiates this one.
- GF(2⁸) classic Reed–Solomon with the Cauchy generator matrix — byte-identical to the
- Crypto (
crypto.rs) — AES-128-GCM session encryption with per-direction nonce salts and sequence-as-AAD; SPAKE2 PIN pairing lives behind thequicfeature. - QUIC control plane (
quic.rs,client.rs, featurequic) — the Hello/Welcome/Start handshake, cert pinning/TOFU, reverse audio, and the embeddableNativeClientconnector. This is the only placetokio/quinnare allowed; the feature is off by default so the core stays runtime-free. - C ABI (
abi.rs) — the versioned surface (punktfunk_abi_version(),PunktfunkConfigcarrying its ownstruct_size) that generatesinclude/punktfunk_core.hvia cbindgen at build time.
Build outputs
The crate builds three ways at once (crate-type = ["lib", "cdylib", "staticlib"]):
| Output | Used by |
|---|---|
lib (rlib) |
the host, probe, and tools link it as a normal Rust crate |
cdylib (.so/.dylib) |
the Swift / Kotlin clients via the C ABI |
staticlib (.a) |
the C test harness and static embedding |
Test
cargo test -p punktfunk-core # unit + proptest + loopback
cargo run -p loss-harness # FEC loss-resilience sweep (no network needed)
bash crates/punktfunk-core/tests/c/run.sh # standalone C-ABI link + round-trip proof
Design invariants (do not regress)
- One core, linked everywhere — protocol/FEC/crypto live only here, behind the stable C ABI.
- No async on the hot path — the per-frame pipeline is native threads only;
quic(tokio/quinn) is control-plane only, feature-gated, off by default. - Security hardening stays intact — the reassembler bounds attacker-controlled fields before
allocating; AES-GCM keeps per-direction nonce salts + seq-as-AAD; the ABI checks
struct_size. Regression tests exist — keep them green.
Related
punktfunk-host— the streaming host built on this core- Clients — the apps that link this core over the C ABI (or directly, in Rust)
- punktfunk-planning:
implementation-plan.md(internal planning repo) — why GF(2¹⁶) FEC, the latency budget, and the architecture thesis