Files
punktfunk/crates/punktfunk-core
enricobuehler dfebb9dfbb chore(safety): hoist the unsafe lints into the workspace tables (WP2c hoist)
undocumented_unsafe_blocks joins unsafe_op_in_unsafe_fn in
[workspace.lints], and the ~100 scattered per-file #![deny(...)] attributes
(85 files) are deleted — a new crate, or a new module in an old one, is now
covered on creation rather than on remembering. The per-file form is how
pf-vkhdr-layer, wdk-probe and half of pf-clipboard stayed uncovered.

There are THREE workspaces, so the claim is made three times: the main
Cargo.toml, packaging/windows/drivers (workspace table + [lints]
workspace = true in all seven members), and packaging/windows/pf-vkhdr-layer
(its [lints] table, previous commit). pf-update now opts into workspace
lints; the two vendored member snapshots (cros-codecs, usbip-sim) stay out
deliberately and now both say so.

Newly-covered fallout was two link-sanity tests (pyrowave-sys, libvpl-sys)
— proofs written. Stale prose that claimed the workspace held
unsafe_op_in_unsafe_fn at "warn" (it has been deny) or pointed at the
deleted attributes is corrected.

nvenc_core.rs is carved OUT of the unsafe_op_in_unsafe_fn fence: its
exemption rationale ("raw entry-table calls almost line for line") was
false — the file makes zero FFI calls. Its unsafe surface is C-union writes
whose soundness hangs on which codec arm is active, and its own 4:4:4 note
records the shipped bug (hevcConfig bytes stamped onto an AV1 config) that
per-operation blocks make visible. It now runs the strictest discipline in
the crate: clippy::multiple_unsafe_ops_per_block at deny, one union access
per block, each naming its codec guard.

Verified here: cargo fmt clean in all three workspaces; native clippy
-D warnings clean for everything that compiles on macOS (the three
pre-existing mac-native failures — pf-client-core wol.rs, pf-encode
dead-code/closure-call, probe mic_burst — reproduce on the clean tree).
Linux/Windows legs ride the .25/.133 gate.
2026-08-11 23:26:28 +02:00
..

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) — the punktfunk/1 data plane over raw UDP: packetization, reassembly (with attacker-bounded limits), pacing, and socket tuning.
  • FEC (fec/) — the wall-breaker. Two codes:
    • GF(2⁸) classic ReedSolomon with the Cauchy generator matrix — byte-identical to the nanors library 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/1 negotiates this one.
  • Crypto (crypto.rs) — AES-128-GCM session encryption with per-direction nonce salts and sequence-as-AAD; SPAKE2 PIN pairing lives behind the quic feature.
  • QUIC control plane (quic.rs, client.rs, feature quic) — the Hello/Welcome/Start handshake, cert pinning/TOFU, reverse audio, and the embeddable NativeClient connector. This is the only place tokio/quinn are allowed; the feature is off by default so the core stays runtime-free.
  • C ABI (abi.rs) — the versioned surface (punktfunk_abi_version(), PunktfunkConfig carrying its own struct_size) that generates include/punktfunk_core.h via 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.
  • 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