**2.5a (L4) — stop `set_var`ing `XAUTHORITY` from a live multithreaded host.** The old connect swapped the process-global var around each `RustConnection::connect` under a mutex. That lock serialises this source against itself and nothing else: `getenv` takes no lock, so every OTHER thread's read raced it — and the concurrency is by construction, since `attach_gamescope_cursor` runs while the PipeWire thread is starting up (libspa plugin load, EGL/CUDA init). The primary path now parses the MIT-MAGIC-COOKIE-1 entry out of the given file itself and hands it to `DefaultStream::connect` + `RustConnection::connect_to_stream_with_auth_info` — the same two steps `RustConnection::connect` performs internally, minus its env-derived auth lookup — so nothing in this process touches the environment. The env swap survives only as a fallback for a file we cannot parse, and a wrong cookie pick cannot do damage: the server rejects it and the fallback (which does libxcb's full family/address match) takes over. Sharing `pf_vdisplay`'s process-wide env lock was not the fix — wrong layer, and it would still not fix `getenv`. **2.5b (L6) — publish the pointer in FRAME coordinates.** `QueryPointer` answers in the nested root's space, but `CursorOverlay::x/y`'s contract is frame pixels, and gamescope's `-w/-h` (nested root) and `-W/-H` (output + PipeWire node) are independent knobs — at `-W 1280 -H 720 -w 640 -h 360` they differ by 2×, so the pointer drew at a fraction of its real position. The root size comes free off the setup reply we already parse; the negotiated frame size arrives from the PipeWire thread's `param_changed` through a new `Arc<AtomicU64>` (`0` = not negotiated ⇒ pass through, as before). Scaling is computed in `i64` — a 5K coordinate times a 5K width overflows `i32`. Position only: the bitmap stays at root scale, warned once so a mismatched session is visible. **2.5c (L7) — the targets are a PROVIDER, not a snapshot.** The list was discovered once, before the game launched. gamescope creates the game's Xwayland at launch and advertises only the FIRST in any child's environ (verified on this box: `--xwayland-count 2` makes `:2` and `:3`, only `:2` is advertised), so the game's display was invisible — and when the connected Big Picture display then reported "gamescope is not drawing the pointer here", the source blanked the cursor for the whole game session, which is the exact regression the module doc says it fixed. The worker now re-runs the provider every 2 s: it adopts new Xwaylands, reconnects dead ones, and `spawn` no longer returns `None` on an empty list — a stream that starts before the game converges instead of staying cursorless. The provider is a host-facade closure, same one-way-edge shape as `FrameChannelSender`. **2.5d (L8) — bound the teardown join.** `Drop` joined the worker unbounded while the worker blocks in `RustConnection` replies with NO read timeout, so a peer that stops answering but keeps its socket open hung capturer teardown — on the session path. Now: a completion channel, `recv_timeout(250 ms)`, then detach with a warning (the thread only touches its own X connections and an `Arc`'d slot). 7 new tests, all host-runnable: the cookie reader against a hostile `.Xauthority` (wrong protocol, wrong display, wildcard entry, truncation mid-length-prefix, an over-long length prefix, a missing file), display-string parsing, and the root→frame mapping incl. the 5K overflow. pf-capture 20/20; workspace clippy --all-targets clean on Linux and windows-msvc. Phase 7.2 owes the on-glass nested-gamescope validation. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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