Files
punktfunk/crates/punktfunk-host
enricobuehlerandClaude Fable 5 ed4e3d3ab6 feat(session): end-game/end-session lifetime on Windows
Phase 2. The lease, the settings, the events and the status surface were already
platform-neutral; what Windows lacked was a way to see processes and a way to ask
one to close.

`procscan` splits per-OS behind one contract. The Windows matcher is a Toolhelp
snapshot plus each process's full image path (`QueryFullProcessImageNameW`), with
creation times from `GetProcessTimes` enforcing the two rules the module exists
for: never adopt a process that predates the launch, never trust a bare pid. Both
matter more here than on Linux — the host is SYSTEM, so it can see and signal
everything, and Windows recycles pids briskly.

Path matching is case-insensitive and separator-aware, and normalizes the `\\?\`
prefix `canonicalize` adds, without which a store-derived path would never compare
equal to a live image path.

There is no reaper argv and no readable environment on Windows, so a spec carrying
only a Steam appid or an env marker matches nothing rather than falling through to
an empty predicate. Steam's appid instead feeds a **veto**: its per-app `Running`
flag in the user's hive can't be trusted to say a game IS running (Steam sets it
around updates too, and leaves it stale after a crash), but it is exactly right for
refusing to declare one gone. If the matcher can't see a game whose exe sits
outside its manifest's install dir, ending the session would be a false positive
the player feels immediately; honoring the veto only ever leaves a stream up.

Termination asks before it insists, which on Windows needs a detail that fails
silently if missed: `EnumWindows` only sees the calling thread's desktop, and the
host's is session 0, which holds none of the user's windows. So the terminating
thread binds to the input desktop first (the pattern `pf-inject`'s `sendinput.rs`
uses), posts `WM_CLOSE` to the game's visible top-level windows, waits, and only
then calls `TerminateProcess` on freshly re-verified pids. Without the desktop
bind the polite pass finds nothing and every game dies unsaved.

Job Objects, planned as WP2.3, are deferred with the reasoning in the design doc:
every Windows launch either hands off through a launcher or the shell — where a job
would wrap a shim that exits immediately — or is a direct exe whose path we already
know, and wiring one in would touch the `CreateProcessAsUserW` token path the UAC
and secure-desktop work depends on.

Also: the watcher's steady-state poll now re-verifies known pids and only re-scans
the whole table once they all vanish (which still catches a game that re-execs).
On Windows a full scan is an `OpenProcess` per process on the box, so this is the
difference between a negligible and a noticeable poll.

Gates: Linux .21 check/clippy/fmt/293 tests green; Windows .133 check + clippy
--all-targets clean, and the 4 procscan tests pass — including the live one that
finds the test process in the real process table and rejects a wrong creation time.
On-glass Windows (Steam/Epic/GOG/Xbox titles, the unsaved-progress check) still
owed; it needs a box with games on it.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-26 18:28:13 +02:00
..

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 at api/openapi.json) drives status, paired devices, and on-demand pairing; the browser UI is in web/.

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
  • 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