Files
rustdesk/libs/scrap
Mariano Abad 1647420993 drm: close the full-review findings (a third latched flag, and two escapees)
The one that matters: the display-cache refresh worker was the THIRD copy of
the wedged-flag hazard. catch_unwind covered only the enumeration, and
thread::spawn panics on EAGAIN after RUNNING was already swapped true, so
either path parked the flag for the process lifetime and every later refresh
- including every udev hotplug - returned early forever. Same ownership
guard as UINPUT_REFRESH_BUSY (the flag is handed back and re-taken mid-loop,
so an unconditional RAII release would clear a replacement worker's flag),
plus a fallible spawn whose failure drops the closure and releases the slot.
DRM_PROBE_IN_FLIGHT, UINPUT_REFRESH_BUSY, now this: the lesson stays
'grep for every site with the shape', and twice was not enough.

Two findings had been flagged in an earlier round and escaped the ledger:
- an unrecognized convert-output fourcc fell through to 'present as BGRA'
  with a debug log, where every sibling validation in that function is a
  hard error that lets the caller fall back to PipeWire. A 64bpp output
  passes the stride check and encodes garbage. Hard error now.
- the trust-boundary validation constants (fourccs, MAX_DIM,
  MAX_FRAME_BYTES) were declared independently on both sides of the split.
  Hoisted into drm_reader, imported by the converter, so the two halves
  cannot drift apart about what data they will touch.

The rest:
- the CI symbol extraction dropped any loader symbol containing a digit and
  degraded to a pass-with-zero-iterations no-op if the b"..." literals were
  ever refactored; digits allowed, count asserted, notice de-hardcoded.
- 'drm' in features was a substring test on the comma-joined string, so a
  future drm-lease feature would have shipped the consent-bypass deb
  without --drm. Exact membership now.
- the security doc claimed the deb is built on an ubuntu18.04 container;
  the only deb job runs on ubuntu-24.04. The 18.04 sentence now says what
  is true: 2.4.95 is an API floor, the binary floor is the build host's.
- DRM_DISPLAY_CACHE poison handling was recover-in-the-writer,
  panic-in-the-readers; both readers now recover like the writer.
- the producer prewarm ran on X11 where no consumer can connect, the same
  inconsistency just fixed for warm_availability. The listener still starts
  (the service outlives sessions; a later Wayland login must find the
  socket), only the prewarm is skipped.
2026-07-29 20:05:45 -03:00
..
2025-01-20 17:59:36 +08:00
2021-03-29 15:59:14 +08:00
2026-06-18 22:37:15 +08:00
2021-07-29 13:33:26 +08:00

Derived from https://github.com/quadrupleslap/scrap

scrap

Scrap records your screen! At least it does if you're on Windows, macOS, or Linux.

Usage

[dependencies]
scrap = "0.5"

Its API is as simple as it gets!

struct Display; /// A screen.
struct Frame; /// An array of the pixels that were on-screen.
struct Capturer; /// A recording instance.

impl Capturer {
    /// Begin recording.
    pub fn new(display: Display) -> io::Result<Capturer>;

    /// Try to get a frame.
    /// Returns WouldBlock if it's not ready yet.
    pub fn frame<'a>(&'a mut self) -> io::Result<Frame<'a>>;

    pub fn width(&self) -> usize;
    pub fn height(&self) -> usize;
}

impl Display {
    /// The primary screen.
    pub fn primary() -> io::Result<Display>;

    /// All the screens.
    pub fn all() -> io::Result<Vec<Display>>;

    pub fn width(&self) -> usize;
    pub fn height(&self) -> usize;
}

impl<'a> ops::Deref for Frame<'a> {
    /// A frame is just an array of bytes.
    type Target = [u8];
}

The Frame Format

  • The frame format is guaranteed to be packed BGRA.
  • The width and height are guaranteed to remain constant.
  • The stride might be greater than the width, and it may also vary between frames.

System Requirements

OS Minimum Requirements
macOS macOS 10.8
Linux XCB + SHM + RandR
Windows DirectX 11.1