URnetwork for Linux

Native Ubuntu 22.04+/24.04 (GNOME/Wayland, amd64+arm64) client, distributed via the Snap Store. Unlike macOS/Windows (privileged daemon + RPC), Linux uses the single-process, Android-like model: one process runs the SDK's DeviceLocal in-process and pumps packets through /dev/net/tun via the SDK's IoLoop — no daemon, no RPC, no wintun. See ../PLAN.md.

Stack

C++17 + GTK4 (gtkmm-4.0) + libadwaita, consuming the shared cgo SDK (libURnetworkSdk.so + the header-only urnetwork_sdk.hpp C++ wrapper) — the same SDK surface the Windows app uses. We use GTK/C++ directly (not gotk4) to avoid a Go GUI binding in the hot path; the SDK-host logic (SdkHost) is shared in spirit with the Windows app, and only the UI toolkit + tun layer differ.

urnetwork (one process, strict snap + network-control)
  GTK4 + libadwaita (C++)  ── SNI tray (raw GDBus) + window
        │  C++ calls over the cgo C ABI (no RPC)
  SdkHost → urnet::NetworkSpaceManager → NetworkSpace → Api/LocalState
                                         DeviceLocal (in-process)
        │  in-process fd loop
  urnet::newIoLoop(device, tunFd) ⇄ /dev/net/tun   (CAP_NET_ADMIN via snap)
        │  ip route (0.0.0.0/1 + 128.0.0.0/1) + resolvectl DNS

Layout

Path	What
src/SdkHost.{hpp,cpp}	single-process core: init, auth, tunnel, connect, provide
src/Tunnel.{hpp,cpp}	/dev/net/tun RAII + ip/resolvectl config (wg-quick style)
src/MainWindow.{hpp,cpp}	GTK4 window: sign-in / home (connect + provide) views
src/Tray.{hpp,cpp}	StatusNotifierItem + com.canonical.dbusmenu over raw GDBus
src/main.cpp	entry: wires SdkHost + window + tray, hide-to-tray keep-running
meson.build, meson_options.txt	build (-Dsdk_arch=amd64|arm64)
snap/snapcraft.yaml	strict snap (core24, gnome extension, network-control)
packaging/	.desktop (+ urnetwork:// SSO scheme) + icon
scripts/fetch-deps.sh	vendor the cgo SDK into third_party/urnetwork-sdk/<arch>/

Build (local dev, on Linux)

# 1. vendor the SDK (from a local zip or SDK_ZIP_URL) — produces
#    third_party/urnetwork-sdk/{amd64,arm64}/{libURnetworkSdk.so,urnetwork_sdk.hpp}
scripts/fetch-deps.sh /path/to/URnetworkSdkLinux.zip

# 2. configure + build
meson setup build -Dsdk_arch=$(dpkg --print-architecture)
meson compile -C build
./build/urnetwork

Dev deps: libgtkmm-4.0-dev libadwaita-1-dev libglib2.0-dev nlohmann-json3-dev meson ninja-build g++ pkg-config.

Build (release snap)

The release pipeline builds this in a Docker container, not on the macOS host — see build/all/linux/ and build/all/run.sh. Each arch runs snapcraft --destructive-mode in an Ubuntu-24.04 container that first stages the matching cgo SDK into third_party/urnetwork-sdk/<arch>/. Output .snap files are uploaded to the GitHub release; Snap Store submission is manual for now.

Confinement notes

• network-control grants /dev/net/tun + CAP_NET_ADMIN — the crux that lets the confined process open + configure the tunnel itself (verified in a container with --cap-add=NET_ADMIN --device=/dev/net/tun).
• resolvectl DNS is best-effort; if systemd-resolved is unavailable the tunnel still routes (DNS just isn't captured on that link).
• The gnome extension supplies the GTK4/libadwaita runtime + portals; we stage only libgtkmm/libadwaita (the C++ binding libs the platform snap lacks).

Not yet at macOS parity

This is the functional core (sign in via password/code, connect best-available, provide toggle, hide-to-tray). Sign-up, Google/Apple browser SSO, the location/provider picker, connection detail, and account/wallet/leaderboard surfaces are the next slice — the SdkHost/Api/ConnectViewController surfaces they need are already wired. See ../NEXTSTEPS.md.