Files
punktfunk/crates/punktfunk-host
enricobuehler 79bd847e85 fix(host): survive Bazzite's SDDM session supervisor in the gamescope takeover
Diagnosed live on the .181 Bazzite F44 box (couldn't connect at all; field
reports of streams dying after 30 s-5 min):

Bazzite autologs into game mode via SDDM with Relogin=true, so the moment the
managed takeover stops gamescope-session-plus@<client>, SDDM logs back in and
restarts it within the same second. The resurrected autologin session then
fights our transient session-plus over the Steam single instance and the GPU
for the whole stream: its wrapper relaunches gamescope every ~7 s (each one
missing the wrapper's hard 5 s readiness window on a slow NVIDIA init), the
churn SIGSEGVs gamescopes, and eventually the streaming gamescope dies with it.
Meanwhile a client that gave up left the pipeline-rebuild retry loop SIGKILLing
and relaunching the box's Steam session for up to ~6 more minutes.

- stop_autologin_sessions: runtime-mask each autologin unit before the SIGKILL
  stop, so no supervisor can restart it underneath the stream; match every
  loaded instance (the unit flaps through activating/failed mid-churn). Every
  restore path unmasks unconditionally (including the desktop-active early
  return), and --runtime keeps the mask in tmpfs so a reboot clears it.
- launch_session: supervise the transient unit while polling for the node —
  the session-plus wrapper kill -9s a gamescope that missed its 5 s readiness
  handshake and exits 1, so relaunch it (after a short driver-settle cooldown)
  instead of waiting the rest of the 45 s on a corpse.
- build_pipeline_with_retry: abort between attempts once the session's QUIC
  connection is closed — no more minutes of Steam churn for a departed client.

Validated live on .181: cold-boot connect streams 2059 frames/45 s (p50
5.1 ms), zero SDDM resurrections while masked, TV session restored+unmasked on
disconnect, warm same-mode reconnect reuses the session (866 frames/15 s).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-07 06:15:12 +00:00
..

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)
  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
  punktfunk1.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
  • design/ — architecture rationale and deep-dive plans