enricobuehler
aa070f2d55
The sharpest memory-safety risk left in this codebase is not an `unsafe` block — it is a hand-written `#[repr(C)]` mirror of an external C struct. Get a field offset wrong and nothing fails to compile and nothing reliably crashes: the library reads a pointer, a length or a pitch out of the wrong bytes. Eleven such structs across five files had NO check at all. Guarded here, each next to the struct it protects: * `AVCUDADeviceContext`, and `AVD3D11VADeviceContext`/`AVD3D11VAFramesContext`. `ffmpeg-sys-next` binds none of them, so these mirrors are the only definitions — and we WRITE through them (`cuda_ctx`, `device`, `bind_flags`). ⚠ The D3D11VA pair is duplicated VERBATIM in two crates (pf-encode's `ffmpeg_win.rs`, pf-client-core's `video_d3d11.rs`) because neither can depend on the other; they must agree with libav and with each other, and now a drift in either is a build error. * The six cuda.h structs. Three were already asserted — but only in `#[cfg(test)]`, so the check ran when someone ran the tests and never in a release build. They are `const` now. The other three, including `CUDA_MEMCPY2D` which is filled on EVERY zero-copy frame, had nothing. * `MsghdrX`, Darwin's `msghdr_x`, which `libc` does not expose. Its layout is not reviewable by eye: the 32-bit fields force padding before each following pointer, so `msg_iov` sits at 16 and not 12. `sendmsg_x`/`recvmsg_x` take the pointer and length from it. * `IPolicyConfigVtbl` — the sharpest of the set. It mirrors an UNDOCUMENTED COM interface, and `set_default_endpoint` is called by SLOT INDEX through a ten-entry `_reserved` gap that carries no names to anchor a review. A field added or resized above it does not break the build; it calls a different function pointer through a mismatched signature. Every assertion is `const _: () = assert!(..)`, so it holds on every build including release and cannot be skipped. The compiler verified the numbers — the sizes and offsets asserted here are the ones the target actually produces, on each platform that compiles the struct. Verified: Linux .21 fmt + both CI clippy steps rc=0 (CUDA + libav CUDA mirrors); Windows .47 full CI clippy set rc=0 + pf-capture tests (D3D11VA pair, COM vtable); macOS `cargo check -p punktfunk-core` (MsghdrX — the only platform that compiles it).
punktfunk-host
The streaming host — the program you run on the machine whose desktop or games you want to stream. For each client that connects, it spins up a virtual display sized to that device, captures it on the GPU, encodes with hardware NVENC/VAAPI/AMF/QSV, and sends it out over a low-latency transport — no physical monitor, no letterboxing, no rearranging your real screens.
It speaks two protocols from one process:
- GameStream — so any Moonlight / Artemis client works day one.
punktfunk/1— punktfunk's own faster protocol (QUIC control plane, GF(2¹⁶) FEC + AES-GCM data plane) that the native clients use.
Runs on Linux (the primary, most battle-tested path) and Windows (x64). The shared protocol,
FEC, and crypto live in punktfunk-core; this crate is everything
platform-facing around it.
What it does
- Per-client virtual displays at the exact WxH@Hz. Linux uses per-compositor backends — KWin, gamescope, Mutter, and Sway/wlroots; Windows uses its own all-Rust IddCx virtual display, even on the secure desktop (UAC / lock screen).
- GPU zero-copy capture → encode. dmabuf → CUDA/Vulkan → NVENC on Linux; on Windows the host pushes frames straight into its own IDD (sealed IDD-push, no screen-scraping) → GPU encode. Encoders auto-select by GPU vendor: NVENC (NVIDIA), VAAPI (Linux AMD/Intel), AMF/QSV (Windows AMD/Intel), or software H.264 as a floor. HDR/10-bit and HEVC 4:4:4 supported.
- Input injection. Mouse/keyboard (libei / gamescope EIS / wlr / Windows SendInput) and virtual gamepads — Xbox 360/One, DualSense, DualShock 4 — with rumble and HID feedback back-channels.
- Audio both ways. Opus audio host→client, plus a virtual microphone the client can talk into.
- Trust & discovery. A persistent host identity, SPAKE2 PIN pairing (default) or TOFU, and mDNS auto-advertisement so clients find the host without typing an IP.
- Management API + web console. A REST API (
mgmt.rs, OpenAPI atapi/openapi.json) drives status, paired devices, and on-demand pairing; the browser UI is inweb/.
Run it
punktfunk-host serve runs inside your desktop session. Bare serve is the secure native-only
default (punktfunk/1 + the management API); add --gamestream on a trusted LAN to also accept
stock Moonlight clients.
# Linux, from the repo root (see the repo README "Running on this box" for the headless recipe):
cargo run -rp punktfunk-host -- serve # native-only (secure default)
cargo run -rp punktfunk-host -- serve --gamestream # + Moonlight compatibility
Then pair from the web console (https://<host-ip>:47992) or the client app.
Most people should install a package rather than run from source — see
packaging/ (apt · rpm/COPR/bootc · Arch/sysext · Windows installer) and
the per-platform guides at docs.punktfunk.unom.io/docs/install.
Subcommands
| Command | Purpose |
|---|---|
serve |
The host (native punktfunk/1 + mgmt API; --gamestream adds Moonlight). |
punktfunk1-host |
Standalone native-protocol listener for testing/measurement (--source virtual, --max-sessions). |
openapi |
Print the management-API OpenAPI spec (regenerates api/openapi.json). |
library |
Inspect the multi-store game library. |
service · driver · web |
Windows: SCM service, driver install, bundled web console. |
*-test / *-selftest / *-probe |
Diagnostics (input, zero-copy, HDR, compositor, gamepads). |
--help lists them all.
Layout
src/
main.rs CLI + subcommand dispatch
config.rs · session_plan.rs · session_tuning.rs · pipeline.rs session setup + the frame pipeline
vdisplay/ per-compositor virtual outputs (kwin · gamescope · mutter · wlroots)
capture/ · capture.rs screen/dmabuf capture (+ Windows IDD-push)
encode/ · encode.rs per-GPU encoders (nvenc · vaapi · ffmpeg_win (AMF/QSV) · sw)
linux/zerocopy/ dmabuf → CUDA → NVENC bridges (EGL/GL tiled, Vulkan LINEAR)
inject/ · inject.rs input backends (libei · wlr · uinput gamepads · UHID DualSense/DS4)
audio/ · audio.rs Opus out + virtual mic (PipeWire / WASAPI)
gamestream/ Moonlight compat: nvhttp · pairing · rtsp · control · stream · gamepad · apps
native.rs the native punktfunk/1 host (QUIC control + native-thread UDP data plane)
mgmt.rs · native_pairing.rs · stats_recorder.rs management API, pairing, perf capture
hdr.rs · library.rs HDR metadata; multi-store game library
linux/ · windows/ platform-confined backends
Related
punktfunk-core— the shared protocol · FEC · crypto core- Clients — the apps that connect (Apple · Linux · Windows · Android · probe)
- Packaging & docs — install & operate
- punktfunk-planning (internal planning repo) — architecture rationale and deep-dive plans