Implement native InputCapture with private EIS receiver transport

Add consent, zones and outside-edge barriers, connection-scoped leases, bounded input queues and keyboard/pointer forwarding. Restore local input on release, locking, topology or keymap changes, receiver loss and emergency escape. Preserve held-key state and distinguish finger stops from absent scroll axes.

Validation: independent review cleared; 5 native InputCapture unit tests; 32 portal tests; official D-Bus contract checks on a private bus; real installed libei receiver interoperability test. Live physical barrier and consent interaction remain to be checked in a desktop session.

Cargo.lock

@@ -4886,6 +4886,18 @@ version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6f6ff9a378485b298a5286656da665ba74413d36db0979633275d2e708145d4"
 
+[[package]]
+name = "reis"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b967ec6489a42067a20724f11987bb96178ea796873cbe1afd25fb93ee6f85f"
+dependencies = [
+ "calloop 0.14.4",
+ "enumflags2",
+ "log",
+ "rustix 1.1.5",
+]
+
 [[package]]
 name = "renderdoc-sys"
 version = "1.1.0"
@@ -7415,6 +7427,7 @@ checksum = "2fb433233f2df9344722454bc7e96465c9d03bff9d77c248f9e7523fe79585b5"
 name = "xdg-desktop-portal-ferese"
 version = "0.1.0"
 dependencies = [
+ "calloop 0.14.4",
  "dirs",
  "ferese-config",
  "ferese-ipc",
@@ -7429,6 +7442,7 @@ dependencies = [
  "memmap2 0.9.11",
  "pipewire",
  "png 0.18.1",
+ "reis",
  "serde",
  "serde_json",
  "tempfile",

compositor/src/handlers/activation.rs

@@ -27,7 +27,7 @@ impl XdgActivationHandler for Ferese {
         data: XdgActivationTokenData,
         surface: WlSurface,
     ) {
-        if self.session_lock.active {
+        if self.session_lock.active || self.input_capture.captures(1) {
             return;
         }
         let valid = data.serial.is_some() && data.timestamp.elapsed() <= TOKEN_MAX_AGE;

compositor/src/handlers/layer_shell.rs

@@ -108,6 +108,7 @@ pub fn handle_commit(state: &mut Ferese, surface: &WlSurface) {
 
     let policy = layer.cached_state();
     if !state.session_lock.active
+        && !state.input_capture.captures(1)
         && policy.keyboard_interactivity == KeyboardInteractivity::Exclusive
         && matches!(policy.layer, Layer::Top | Layer::Overlay)
     {

compositor/src/handlers/xdg_shell.rs

@@ -254,7 +254,7 @@ impl XdgShellHandler for Ferese {
     }
 
     fn grab(&mut self, surface: PopupSurface, seat: wl_seat::WlSeat, serial: Serial) {
-        if self.session_lock.active {
+        if self.session_lock.active || self.input_capture.active() {
             return;
         }
         let Some(seat) = Seat::from_resource(&seat) else {

compositor/src/input.rs

@@ -59,6 +59,27 @@ impl Ferese {
             self.focus_lock_surface();
         }
 
+        if self.input_capture.active()
+            && matches!(
+                &event,
+                InputEvent::GestureSwipeBegin { .. }
+                    | InputEvent::GestureSwipeUpdate { .. }
+                    | InputEvent::GestureSwipeEnd { .. }
+                    | InputEvent::GesturePinchBegin { .. }
+                    | InputEvent::GesturePinchUpdate { .. }
+                    | InputEvent::GesturePinchEnd { .. }
+                    | InputEvent::GestureHoldBegin { .. }
+                    | InputEvent::GestureHoldEnd { .. }
+                    | InputEvent::TouchDown { .. }
+                    | InputEvent::TouchMotion { .. }
+                    | InputEvent::TouchUp { .. }
+                    | InputEvent::TouchCancel { .. }
+                    | InputEvent::TouchFrame { .. }
+            )
+        {
+            return;
+        }
+
         match event {
             InputEvent::GestureSwipeBegin { event } => {
                 let pointer = seat.get_pointer().expect("seat has a pointer");
@@ -143,6 +164,13 @@ impl Ferese {
                 let keycode = event.key_code();
                 let state = event.state();
 
+                let was_captured = self.input_capture.active();
+                if self.input_capture.captures(1) {
+                    keyboard.unset_grab(self);
+                    if keyboard.current_focus().is_some() {
+                        keyboard.set_focus(self, None, SERIAL_COUNTER.next_serial());
+                    }
+                }
                 keyboard.input::<(), _>(
                     self,
                     keycode,
@@ -160,6 +188,17 @@ impl Ferese {
                             return FilterResult::Forward;
                         }
                         let symbol = keysym.modified_sym().raw();
+                        if data.input_capture.active() && emergency_shortcut_escape(symbol, modifiers.ctrl, modifiers.alt) {
+                            if state == KeyState::Pressed {
+                                data.input_capture.disable_all();
+                                data.intercepted_keys.insert(keycode);
+                            }
+                            return FilterResult::Intercept(());
+                        }
+                        if data.input_capture.captures(1) {
+                            data.input_capture.push(serde_json::json!({"type":"key", "key":keycode.raw().saturating_sub(8), "pressed":state == KeyState::Pressed}));
+                            return FilterResult::Forward;
+                        }
                         if data.overview.is_active()
                             && matches!(symbol, keysyms::KEY_Return | keysyms::KEY_KP_Enter)
                         {
@@ -249,12 +288,18 @@ impl Ferese {
                         FilterResult::Intercept(())
                     },
                 );
+                if was_captured && !self.input_capture.active() {
+                    self.restore_input_capture_focus();
+                }
             }
             InputEvent::PointerMotionAbsolute { event, .. } => {
                 let Some(position) = self.absolute_event_position(&event) else {
                     return;
                 };
                 let pointer = self.seat.get_pointer().expect("seat has a pointer");
+                if self.capture_pointer_motion(pointer.current_location(), position, true) {
+                    return;
+                }
                 let position = self.constrain_pointer_position(&pointer, position);
 
                 pointer.motion(
@@ -284,6 +329,9 @@ impl Ferese {
                 };
                 let delta = event.delta();
                 let delta_unaccel = event.delta_unaccel();
+                if self.capture_pointer_motion(position, position + delta, false) {
+                    return;
+                }
 
                 pointer.relative_motion(
                     self,
@@ -313,6 +361,12 @@ impl Ferese {
                 crate::backends::direct::render_all(self);
             }
             InputEvent::PointerButton { event, .. } => {
+                if self.input_capture.active() {
+                    if self.input_capture.captures(2) {
+                        self.input_capture.push(serde_json::json!({"type":"button", "button":event.button_code(), "pressed":event.state() == ButtonState::Pressed}));
+                    }
+                    return;
+                }
                 let pointer = self.seat.get_pointer().expect("seat has a pointer");
                 let serial = SERIAL_COUNTER.next_serial();
 
@@ -411,6 +465,12 @@ impl Ferese {
                 let vertical = event.amount(Axis::Vertical).unwrap_or_else(|| {
                     event.amount_v120(Axis::Vertical).unwrap_or(0.0) * 15.0 / 120.0
                 });
+                if self.input_capture.active() {
+                    if self.input_capture.captures(2) {
+                        self.input_capture.push(serde_json::json!({"type":"scroll", "x":horizontal, "y":vertical, "v120_x":event.amount_v120(Axis::Horizontal), "v120_y":event.amount_v120(Axis::Vertical), "stop_x":source == AxisSource::Finger && event.amount(Axis::Horizontal) == Some(0.0), "stop_y":source == AxisSource::Finger && event.amount(Axis::Vertical) == Some(0.0)}));
+                    }
+                    return;
+                }
                 let pointer = self.seat.get_pointer().expect("seat has a pointer");
                 if self.scroll_overview_strip(
                     pointer.current_location(),
@@ -664,6 +724,9 @@ impl Ferese {
     }
 
     fn focus_window_at(&mut self, position: Point<f64, Logical>, serial: Serial, raise: bool) {
+        if self.input_capture.captures(1) {
+            return;
+        }
         if self.session_lock.active {
             self.focus_output_at(position);
             self.focus_lock_surface();

compositor/src/input_capture.rs

@@ -0,0 +1,719 @@
+use std::{
+    collections::{HashMap, VecDeque},
+    sync::mpsc::SyncSender,
+};
+
+use ferese_ipc::Response;
+use serde::Deserialize;
+use serde_json::{Value, json};
+use smithay::wayland::keyboard_shortcuts_inhibit::KeyboardShortcutsInhibitorSeat;
+
+const MAX_SESSIONS: usize = 8;
+const MAX_BARRIERS: usize = 64;
+const MAX_EVENTS: usize = 512;
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub(crate) struct Zone {
+    pub width: u32,
+    pub height: u32,
+    pub x: i32,
+    pub y: i32,
+}
+
+impl Zone {
+    fn right(self) -> f64 {
+        f64::from(self.x) + f64::from(self.width)
+    }
+
+    fn bottom(self) -> f64 {
+        f64::from(self.y) + f64::from(self.height)
+    }
+
+    fn contains(self, point: (f64, f64)) -> bool {
+        point.0 >= f64::from(self.x)
+            && point.0 < self.right()
+            && point.1 >= f64::from(self.y)
+            && point.1 < self.bottom()
+    }
+}
+
+#[derive(Clone, Debug, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub(crate) struct Barrier {
+    pub id: u32,
+    pub position: [i32; 4],
+}
+
+#[derive(Clone, Copy, Debug)]
+enum Edge {
+    Left,
+    Right,
+    Top,
+    Bottom,
+}
+
+fn edge(barrier: &Barrier, zones: &[Zone]) -> Option<Edge> {
+    if barrier.id == 0 {
+        return None;
+    }
+    let [x1, y1, x2, y2] = barrier.position.map(f64::from);
+    let horizontal = y1 == y2 && x1 <= x2;
+    let vertical = x1 == x2 && y1 <= y2;
+    if !horizontal && !vertical {
+        return None;
+    }
+    for zone in zones {
+        let found = if horizontal && x1 >= f64::from(zone.x) && x2 < zone.right() {
+            if y1 == f64::from(zone.y) {
+                Some(Edge::Top)
+            } else if y1 == zone.bottom() {
+                Some(Edge::Bottom)
+            } else {
+                None
+            }
+        } else if vertical && y1 >= f64::from(zone.y) && y2 < zone.bottom() {
+            if x1 == f64::from(zone.x) {
+                Some(Edge::Left)
+            } else if x1 == zone.right() {
+                Some(Edge::Right)
+            } else {
+                None
+            }
+        } else {
+            None
+        };
+        let Some(found) = found else {
+            continue;
+        };
+        let intersects_neighbor = zones.iter().any(|other| {
+            if other == zone {
+                return false;
+            }
+            match found {
+                Edge::Top | Edge::Bottom => {
+                    let outside = y1
+                        + if matches!(found, Edge::Top) {
+                            -0.5
+                        } else {
+                            0.5
+                        };
+                    outside >= f64::from(other.y)
+                        && outside < other.bottom()
+                        && x1 < other.right()
+                        && x2 + 1.0 > f64::from(other.x)
+                }
+                Edge::Left | Edge::Right => {
+                    let outside = x1
+                        + if matches!(found, Edge::Left) {
+                            -0.5
+                        } else {
+                            0.5
+                        };
+                    outside >= f64::from(other.x)
+                        && outside < other.right()
+                        && y1 < other.bottom()
+                        && y2 + 1.0 > f64::from(other.y)
+                }
+            }
+        });
+        if !intersects_neighbor {
+            return Some(found);
+        }
+    }
+    None
+}
+
+fn crossed(barrier: &Barrier, edge: Edge, from: (f64, f64), to: (f64, f64)) -> Option<f64> {
+    let [x1, y1, x2, y2] = barrier.position.map(f64::from);
+    let (distance, movement, start, end) = match edge {
+        Edge::Left if from.0 >= x1 && to.0 < x1 => (x1 - from.0, to.0 - from.0, y1, y2 + 1.0),
+        Edge::Right if from.0 < x1 && to.0 >= x1 => (x1 - from.0, to.0 - from.0, y1, y2 + 1.0),
+        Edge::Top if from.1 >= y1 && to.1 < y1 => (y1 - from.1, to.1 - from.1, x1, x2 + 1.0),
+        Edge::Bottom if from.1 < y1 && to.1 >= y1 => (y1 - from.1, to.1 - from.1, x1, x2 + 1.0),
+        _ => return None,
+    };
+    let fraction = distance / movement;
+    let along = if matches!(edge, Edge::Left | Edge::Right) {
+        from.1 + (to.1 - from.1) * fraction
+    } else {
+        from.0 + (to.0 - from.0) * fraction
+    };
+    (fraction >= 0.0 && fraction <= 1.0 && along >= start && along < end).then_some(fraction)
+}
+
+struct Session {
+    owner: u64,
+    capabilities: u32,
+    barriers: Vec<(Barrier, Edge)>,
+    enabled: bool,
+    closed: bool,
+    activation: Option<u32>,
+    events: VecDeque<Value>,
+}
+
+#[derive(Default)]
+pub(crate) struct InputCapture {
+    sessions: HashMap<u64, Session>,
+    zones: Vec<Zone>,
+    zone_set: u32,
+    next_session: u64,
+    next_activation: u32,
+    active: Option<u64>,
+    last_absolute: Option<(f64, f64)>,
+    pub(crate) restore_focus: bool,
+    waiters: HashMap<u64, (u64, u64, SyncSender<Response>)>,
+}
+
+impl InputCapture {
+    pub(crate) fn update_zones(&mut self, mut zones: Vec<Zone>) {
+        zones.sort_by_key(|zone| (zone.x, zone.y, zone.width, zone.height));
+        zones.dedup();
+        if self.zones == zones {
+            return;
+        }
+        self.zones = zones;
+        self.zone_set = self.zone_set.wrapping_add(1);
+        self.disable_all();
+        let ids = self.sessions.keys().copied().collect::<Vec<_>>();
+        for id in ids {
+            self.sessions.get_mut(&id).unwrap().barriers.clear();
+            self.enqueue(id, json!({"type":"zones", "zone_set":self.zone_set}));
+        }
+        self.flush();
+    }
+
+    pub(crate) fn register(&mut self, owner: u64, capabilities: u32) -> Result<u64, String> {
+        if self.sessions.len() >= MAX_SESSIONS || capabilities == 0 || capabilities & !3 != 0 {
+            return Err("Unsupported capabilities or input capture session limit reached".into());
+        }
+        self.next_session = self
+            .next_session
+            .checked_add(1)
+            .ok_or("Input capture IDs exhausted")?;
+        let id = self.next_session;
+        self.sessions.insert(
+            id,
+            Session {
+                owner,
+                capabilities,
+                barriers: Vec::new(),
+                enabled: false,
+                closed: false,
+                activation: None,
+                events: VecDeque::new(),
+            },
+        );
+        Ok(id)
+    }
+
+    pub(crate) fn zones(&self, id: u64) -> Result<Value, String> {
+        self.session(id)?;
+        Ok(
+            json!({"zone_set":self.zone_set, "zones":self.zones.iter().map(|zone|
+            (zone.width, zone.height, zone.x, zone.y)).collect::<Vec<_>>()}),
+        )
+    }
+
+    fn session(&self, id: u64) -> Result<&Session, String> {
+        self.sessions
+            .get(&id)
+            .ok_or("Unknown input capture session".into())
+    }
+
+    pub(crate) fn set_barriers(
+        &mut self,
+        id: u64,
+        zone_set: u32,
+        barriers: Vec<Barrier>,
+    ) -> Result<Vec<u32>, String> {
+        self.session(id)?;
+        if barriers.len() > MAX_BARRIERS {
+            return Err("Too many pointer barriers".into());
+        }
+        self.disable(id)?;
+        let mut accepted = Vec::new();
+        let mut failed = Vec::new();
+        let mut counts = HashMap::new();
+        for barrier in &barriers {
+            *counts.entry(barrier.id).or_insert(0) += 1;
+        }
+        for barrier in barriers {
+            let kind = edge(&barrier, &self.zones);
+            if zone_set != self.zone_set || counts[&barrier.id] != 1 || kind.is_none() {
+                failed.push(barrier.id);
+            } else {
+                accepted.push((barrier, kind.unwrap()));
+            }
+        }
+        self.sessions.get_mut(&id).unwrap().barriers = accepted;
+        Ok(failed)
+    }
+
+    pub(crate) fn enable(&mut self, id: u64) -> Result<(), String> {
+        let session = self
+            .sessions
+            .get_mut(&id)
+            .ok_or("Unknown input capture session")?;
+        if session.closed {
+            return Err("Input capture session is closed".into());
+        }
+        session.enabled = true;
+        Ok(())
+    }
+
+    pub(crate) fn has_sessions(&self) -> bool {
+        !self.sessions.is_empty()
+    }
+
+    pub(crate) fn active(&self) -> bool {
+        self.active.is_some()
+    }
+
+    pub(crate) fn captures(&self, capability: u32) -> bool {
+        self.active
+            .and_then(|id| self.sessions.get(&id))
+            .is_some_and(|session| session.capabilities & capability != 0)
+    }
+
+    pub(crate) fn motion(&mut self, from: (f64, f64), to: (f64, f64), allowed: bool) -> bool {
+        if self.active() {
+            return true;
+        }
+        if !allowed
+            || ![from.0, from.1, to.0, to.1]
+                .iter()
+                .all(|value| value.is_finite())
+        {
+            return false;
+        }
+        let hit = self
+            .sessions
+            .iter()
+            .filter(|(_, session)| session.enabled && !session.closed)
+            .flat_map(|(id, session)| {
+                session.barriers.iter().filter_map(move |(barrier, kind)| {
+                    crossed(barrier, *kind, from, to).map(|fraction| (*id, barrier.id, fraction))
+                })
+            })
+            .min_by(|left, right| left.2.total_cmp(&right.2).then(left.0.cmp(&right.0)));
+        let Some((id, barrier, _)) = hit else {
+            return false;
+        };
+        self.next_activation = self.next_activation.wrapping_add(1);
+        let activation = self.next_activation;
+        self.active = Some(id);
+        let session = self.sessions.get_mut(&id).unwrap();
+        session.activation = Some(activation);
+        self.enqueue(
+            id,
+            json!({"type":"activated", "activation_id":activation,
+            "barrier_id":barrier, "cursor_position":to}),
+        );
+        self.flush();
+        true
+    }
+
+    fn enqueue(&mut self, id: u64, event: Value) {
+        let Some(session) = self.sessions.get_mut(&id) else {
+            return;
+        };
+        if session.closed {
+            return;
+        }
+        if session.events.len() >= MAX_EVENTS {
+            session.events.clear();
+            session.events.push_back(json!({"type":"closed"}));
+            session.closed = true;
+            session.enabled = false;
+            session.activation = None;
+            if self.active == Some(id) {
+                self.active = None;
+                self.last_absolute = None;
+                self.restore_focus = true;
+            }
+            return;
+        }
+        session.events.push_back(event);
+    }
+
+    pub(crate) fn push(&mut self, event: Value) {
+        if let Some(id) = self.active {
+            self.enqueue(id, event);
+            self.flush();
+        }
+    }
+
+    pub(crate) fn absolute_delta(&mut self, point: (f64, f64)) -> (f64, f64) {
+        let previous = self.last_absolute.replace(point).unwrap_or(point);
+        (point.0 - previous.0, point.1 - previous.1)
+    }
+
+    pub(crate) fn close_all(&mut self) {
+        if self.active.take().is_some() {
+            self.restore_focus = true;
+        }
+        self.last_absolute = None;
+        self.sessions.clear();
+        self.flush();
+    }
+
+    pub(crate) fn release(&mut self, id: u64, activation: Option<u32>) -> Result<(), String> {
+        let session = self.session(id)?;
+        if activation.is_some() && session.activation != activation {
+            return Err("Stale input capture activation".into());
+        }
+        if self.active == Some(id) {
+            self.active = None;
+            self.last_absolute = None;
+            self.restore_focus = true;
+            let session = self.sessions.get_mut(&id).unwrap();
+            let activation = session.activation.take();
+            self.enqueue(
+                id,
+                json!({"type":"deactivated", "activation_id":activation}),
+            );
+            self.flush();
+        }
+        Ok(())
+    }
+
+    pub(crate) fn disable(&mut self, id: u64) -> Result<(), String> {
+        self.release(id, None)?;
+        let session = self.sessions.get_mut(&id).unwrap();
+        if session.enabled {
+            session.enabled = false;
+            self.enqueue(id, json!({"type":"disabled"}));
+        }
+        self.flush();
+        Ok(())
+    }
+
+    pub(crate) fn disable_all(&mut self) {
+        let ids = self.sessions.keys().copied().collect::<Vec<_>>();
+        for id in ids {
+            let _ = self.disable(id);
+        }
+    }
+
+    pub(crate) fn valid_position(&self, point: (f64, f64)) -> bool {
+        point.0.is_finite()
+            && point.1.is_finite()
+            && self.zones.iter().any(|zone| zone.contains(point))
+    }
+
+    pub(crate) fn watch(
+        &mut self,
+        owner: u64,
+        request: u64,
+        id: u64,
+        response: SyncSender<Response>,
+    ) {
+        if !self.sessions.contains_key(&id)
+            || self.waiters.len() >= MAX_SESSIONS
+            || self.waiters.values().any(|(_, token, _)| *token == id)
+        {
+            let _ = response.try_send(Response::error(
+                request,
+                "invalid_capture",
+                "Unknown or already watched input capture session",
+            ));
+            return;
+        }
+        self.waiters.insert(owner, (request, id, response));
+        self.flush();
+    }
+
+    fn flush(&mut self) {
+        let ready = self
+            .waiters
+            .iter()
+            .filter_map(|(owner, (_, id, _))| {
+                self.sessions
+                    .get(id)
+                    .is_none_or(|session| !session.events.is_empty())
+                    .then_some(*owner)
+            })
+            .collect::<Vec<_>>();
+        for owner in ready {
+            let (request, id, response) = self.waiters.remove(&owner).unwrap();
+            let result = if let Some(session) = self.sessions.get_mut(&id) {
+                json!({"events":session.events.drain(..).collect::<Vec<_>>()})
+            } else {
+                json!({"events":[{"type":"closed"}]})
+            };
+            let _ = response.try_send(Response::success(request, result));
+        }
+    }
+
+    pub(crate) fn remove_owner(&mut self, owner: u64) {
+        self.waiters.remove(&owner);
+        let ids = self
+            .sessions
+            .iter()
+            .filter_map(|(id, session)| (session.owner == owner).then_some(*id))
+            .collect::<Vec<_>>();
+        for id in ids {
+            let _ = self.release(id, None);
+            self.sessions.remove(&id);
+        }
+        self.flush();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn zones() -> Vec<Zone> {
+        vec![
+            Zone {
+                width: 1920,
+                height: 1080,
+                x: 0,
+                y: 0,
+            },
+            Zone {
+                width: 1920,
+                height: 1080,
+                x: 1920,
+                y: 0,
+            },
+        ]
+    }
+
+    #[test]
+    fn barriers_use_inclusive_pixel_span_and_only_outer_union_edges() {
+        let zones = zones();
+        for position in [
+            [0, 0, 1919, 0],
+            [0, 1080, 1919, 1080],
+            [1920, 0, 3839, 0],
+            [3840, 0, 3840, 1079],
+            [0, 0, 0, 1079],
+        ] {
+            assert!(
+                edge(&Barrier { id: 1, position }, &zones).is_some(),
+                "{position:?}"
+            );
+        }
+        for position in [
+            [1920, 0, 1920, 1079],
+            [0, 0, 1920, 0],
+            [5, 10, 8, 13],
+            [50, 50, 50, 200],
+            [0, 5, 0, 4],
+        ] {
+            assert!(
+                edge(&Barrier { id: 1, position }, &zones).is_none(),
+                "{position:?}"
+            );
+        }
+        let barrier = Barrier {
+            id: 1,
+            position: [3840, 0, 3840, 1079],
+        };
+        assert!(crossed(&barrier, Edge::Right, (3830.0, 1079.5), (3900.0, 1079.5)).is_some());
+        assert!(crossed(&barrier, Edge::Right, (3830.0, 1080.0), (3900.0, 1080.0)).is_none());
+    }
+
+    #[test]
+    fn absolute_samples_report_incremental_motion_and_reset_on_release() {
+        let mut capture = InputCapture::default();
+        assert_eq!(capture.absolute_delta((100.0, 50.0)), (0.0, 0.0));
+        assert_eq!(capture.absolute_delta((110.0, 55.0)), (10.0, 5.0));
+        assert_eq!(capture.absolute_delta((120.0, 60.0)), (10.0, 5.0));
+        capture.close_all();
+        assert_eq!(capture.absolute_delta((600.0, 700.0)), (0.0, 0.0));
+    }
+
+    #[test]
+    fn duplicate_ids_are_rejected_without_installing_a_barrier() {
+        let mut capture = InputCapture::default();
+        capture.update_zones(zones());
+        let id = capture.register(1, 3).unwrap();
+        let barrier = Barrier {
+            id: 9,
+            position: [3840, 0, 3840, 1079],
+        };
+        let failed = capture
+            .set_barriers(id, capture.zone_set, vec![barrier.clone(), barrier])
+            .unwrap();
+        assert_eq!(failed, vec![9, 9]);
+        assert!(capture.sessions[&id].barriers.is_empty());
+    }
+
+    #[test]
+    fn stalled_control_and_input_queues_close_and_restore_local_focus() {
+        let mut capture = InputCapture::default();
+        capture.update_zones(zones());
+        let id = capture.register(1, 3).unwrap();
+        capture
+            .set_barriers(
+                id,
+                capture.zone_set,
+                vec![Barrier {
+                    id: 1,
+                    position: [3840, 0, 3840, 1079],
+                }],
+            )
+            .unwrap();
+        capture.enable(id).unwrap();
+        assert!(capture.motion((3839.0, 50.0), (3900.0, 50.0), true));
+        for _ in 0..MAX_EVENTS + 10 {
+            capture.push(json!({"type":"motion", "x":1.0, "y":0.0}));
+        }
+        assert!(!capture.active());
+        assert!(capture.restore_focus);
+        assert!(capture.enable(id).is_err());
+        assert_eq!(capture.sessions[&id].events.len(), 1);
+        assert_eq!(capture.sessions[&id].events[0]["type"], "closed");
+
+        let id = capture.register(2, 2).unwrap();
+        for _ in 0..MAX_EVENTS + 10 {
+            capture.enable(id).ok();
+            capture.disable(id).unwrap();
+        }
+        assert_eq!(capture.sessions[&id].events.len(), 1);
+        assert!(capture.sessions[&id].closed);
+    }
+
+    #[test]
+    fn release_preserves_enable_but_topology_changes_disable_and_invalidate() {
+        let mut capture = InputCapture::default();
+        capture.update_zones(zones());
+        let id = capture.register(9, 3).unwrap();
+        let barrier = Barrier {
+            id: 1,
+            position: [3840, 0, 3840, 1079],
+        };
+        assert!(
+            capture
+                .set_barriers(id, capture.zone_set, vec![barrier])
+                .unwrap()
+                .is_empty()
+        );
+        capture.enable(id).unwrap();
+        assert!(capture.motion((3839.0, 50.0), (3900.0, 50.0), true));
+        let activation = capture.sessions[&id].activation.unwrap();
+        assert!(
+            capture
+                .release(id, Some(activation.wrapping_add(1)))
+                .is_err()
+        );
+        capture.release(id, Some(activation)).unwrap();
+        assert!(capture.sessions[&id].enabled);
+        capture.update_zones(vec![zones()[0]]);
+        assert!(!capture.active());
+        assert!(!capture.sessions[&id].enabled);
+        assert!(capture.sessions[&id].barriers.is_empty());
+    }
+}
+
+impl crate::Ferese {
+    pub(crate) fn refresh_input_capture_zones(&mut self) {
+        if !self.input_capture.has_sessions() {
+            return;
+        }
+        let active = self.input_capture.active();
+        let zones = self
+            .space
+            .outputs()
+            .filter_map(|output| {
+                let rect = self.space.output_geometry(output)?;
+                Some(Zone {
+                    width: u32::try_from(rect.size.w).ok()?,
+                    height: u32::try_from(rect.size.h).ok()?,
+                    x: rect.loc.x,
+                    y: rect.loc.y,
+                })
+            })
+            .collect();
+        self.input_capture.update_zones(zones);
+        if active && !self.input_capture.active() {
+            self.restore_input_capture_focus();
+        }
+    }
+
+    pub(crate) fn restore_input_capture_focus(&mut self) {
+        self.input_capture.restore_focus = false;
+        self.cursor_redraw_pending = true;
+        if !self.session_lock.active {
+            self.restore_keyboard_focus();
+            if let Some(pointer) = self.seat.get_pointer() {
+                let location = pointer.current_location();
+                pointer.motion(
+                    self,
+                    self.surface_under(location),
+                    &smithay::input::pointer::MotionEvent {
+                        location,
+                        serial: smithay::utils::SERIAL_COUNTER.next_serial(),
+                        time: 0,
+                    },
+                );
+                pointer.frame(self);
+            }
+        }
+    }
+
+    pub(crate) fn capture_pointer_motion(
+        &mut self,
+        from: smithay::utils::Point<f64, smithay::utils::Logical>,
+        to: smithay::utils::Point<f64, smithay::utils::Logical>,
+        absolute: bool,
+    ) -> bool {
+        let pointer = self.seat.get_pointer().expect("seat has pointer");
+        let active = self.input_capture.active();
+        let allowed = !self.session_lock.active
+            && !self.overview.is_presenting()
+            && !pointer.is_grabbed()
+            && !self.swipe.active()
+            && self
+                .seat
+                .get_keyboard()
+                .is_none_or(|keyboard| !keyboard.is_grabbed())
+            && self
+                .seat
+                .get_touch()
+                .is_none_or(|touch| !touch.is_grabbed())
+            && !self.seat.keyboard_shortcuts_inhibited();
+        if !self
+            .input_capture
+            .motion((from.x, from.y), (to.x, to.y), allowed)
+        {
+            return false;
+        }
+        let delta = if absolute {
+            self.input_capture.absolute_delta((to.x, to.y))
+        } else {
+            (to.x - from.x, to.y - from.y)
+        };
+        if !active {
+            self.cursor_redraw_pending = true;
+            pointer.motion(
+                self,
+                None,
+                &smithay::input::pointer::MotionEvent {
+                    location: from,
+                    serial: smithay::utils::SERIAL_COUNTER.next_serial(),
+                    time: 0,
+                },
+            );
+            pointer.frame(self);
+            if self.input_capture.captures(1) {
+                let keyboard = self.seat.get_keyboard().expect("seat has keyboard");
+                let keys = keyboard
+                    .pressed_keys()
+                    .iter()
+                    .filter(|key| !self.intercepted_keys.contains(key))
+                    .map(|key| key.raw().saturating_sub(8))
+                    .collect::<Vec<_>>();
+                keyboard.set_focus(self, None, smithay::utils::SERIAL_COUNTER.next_serial());
+                self.input_capture.push(json!({"type":"keys", "keys":keys}));
+            }
+        } else if self.input_capture.captures(2) {
+            self.input_capture
+                .push(json!({"type":"motion", "x":delta.0, "y":delta.1}));
+        }
+        true
+    }
+}

compositor/src/ipc.rs

@@ -47,6 +47,7 @@ const DEADLINE_IDLE: Duration = Duration::from_secs(1);
 
 #[derive(Debug)]
 struct IpcCall {
+    native_portal: bool,
     owner: u64,
     request: Request,
     response: SyncSender<Response>,
@@ -121,13 +122,42 @@ pub(crate) fn init(
                 let call = match event {
                     IpcEvent::Call(call) => call,
                     IpcEvent::Closed(owner) => {
+                        let captured = state.input_capture.active();
+                        state.input_capture.remove_owner(owner);
+                        if captured && !state.input_capture.active() {
+                            state.restore_input_capture_focus();
+                        }
                         state.portal_shortcuts.remove(owner);
                         state.portal_session.remove(owner);
                         state.refresh_idle_inhibition();
                         return;
                     }
                 };
-                if call.request.command == "session-watch" {
+                if call.request.command.starts_with("input-capture-") && !call.native_portal {
+                    let _ = call.response.try_send(Response::error(
+                        call.request.id,
+                        "access_denied",
+                        "Input capture is restricted to the native portal",
+                    ));
+                } else if call.request.command == "input-capture-watch" {
+                    if let Err(error) = validate_request(&call.request) {
+                        let _ = call.response.try_send(Response::error(
+                            call.request.id,
+                            error.code,
+                            error.message,
+                        ));
+                    } else if let Some(id) = call.request.args["session"].as_u64() {
+                        state
+                            .input_capture
+                            .watch(call.owner, call.request.id, id, call.response);
+                    } else {
+                        let _ = call.response.try_send(Response::error(
+                            call.request.id,
+                            "invalid_argument",
+                            "Missing capture session",
+                        ));
+                    }
+                } else if call.request.command == "session-watch" {
                     if let Err(error) = validate_request(&call.request) {
                         let _ = call.response.send(Response::error(
                             call.request.id,
@@ -310,6 +340,7 @@ fn serve_connection(
     signal: LoopSignal,
     owner: u64,
 ) {
+    let native_portal = crate::handlers::window_capture::is_portal(&stream);
     let _connection = IpcConnection {
         owner,
         sender: sender.clone(),
@@ -337,6 +368,7 @@ fn serve_connection(
         let screenshot_requested =
             matches!(request.command.as_str(), "screenshot" | "screenshot-window");
         let call = IpcEvent::Call(IpcCall {
+            native_portal,
             owner,
             request,
             response,
@@ -417,6 +449,8 @@ impl Ferese {
             && !matches!(
                 request.command.as_str(),
                 "portal-shortcuts-poll"
+                    | "input-capture-disable"
+                    | "input-capture-release"
                     | "get-session-state"
                     | "portal-inhibit"
                     | "portal-monitor-register"
@@ -525,6 +559,106 @@ impl Ferese {
             "portal-shortcuts-poll" => {
                 return Ok(self.portal_shortcuts.poll(owner, self.session_lock.active));
             }
+            "input-capture-register" => {
+                if self.session_lock.active {
+                    return Err(CommandError::new("session_locked", "Session is locked"));
+                }
+                let id = self
+                    .input_capture
+                    .register(owner, u32_arg(args, "capabilities")?)
+                    .map_err(|e| CommandError::new("invalid_capture", e))?;
+                self.refresh_input_capture_zones();
+                let keyboard = self.seat.get_keyboard().expect("seat has keyboard");
+                let keymap = keyboard.with_xkb_state(self, |state| {
+                    let xkb = state.xkb().lock().unwrap();
+                    // SAFETY: the ref-counted keymap does not escape the locked Xkb;
+                    // only its owned string is retained for the EIS keyboard.
+                    unsafe { xkb.keymap() }
+                        .get_as_string(smithay::input::keyboard::xkb::KEYMAP_FORMAT_TEXT_V1)
+                });
+                return Ok(json!({"session":id, "keymap":keymap}));
+            }
+            "input-capture-zones" => {
+                self.refresh_input_capture_zones();
+                return self
+                    .input_capture
+                    .zones(
+                        args["session"].as_u64().ok_or_else(|| {
+                            CommandError::new("invalid_capture", "Missing session")
+                        })?,
+                    )
+                    .map_err(|e| CommandError::new("invalid_capture", e));
+            }
+            "input-capture-barriers" => {
+                self.refresh_input_capture_zones();
+                let id = args["session"]
+                    .as_u64()
+                    .ok_or_else(|| CommandError::new("invalid_capture", "Missing session"))?;
+                let barriers = serde_json::from_value(args["barriers"].clone())
+                    .map_err(|_| CommandError::new("invalid_capture", "Invalid barriers"))?;
+                let active = self.input_capture.active();
+                let failed = self
+                    .input_capture
+                    .set_barriers(id, u32_arg(args, "zone_set")?, barriers)
+                    .map_err(|e| CommandError::new("invalid_capture", e))?;
+                if active && !self.input_capture.active() {
+                    self.restore_input_capture_focus();
+                }
+                return Ok(json!({"failed_barriers":failed}));
+            }
+            "input-capture-enable" => {
+                self.refresh_input_capture_zones();
+                let id = args["session"]
+                    .as_u64()
+                    .ok_or_else(|| CommandError::new("invalid_capture", "Missing session"))?;
+                self.input_capture
+                    .enable(id)
+                    .map_err(|e| CommandError::new("invalid_capture", e))?;
+            }
+            "input-capture-disable" | "input-capture-release" => {
+                let id = args["session"]
+                    .as_u64()
+                    .ok_or_else(|| CommandError::new("invalid_capture", "Missing session"))?;
+                let position = args
+                    .get("cursor_position")
+                    .filter(|position| !position.is_null())
+                    .map(|position| {
+                        let position = position
+                            .as_array()
+                            .filter(|values| values.len() == 2)
+                            .ok_or("Invalid cursor position")?;
+                        let point = (
+                            position[0].as_f64().ok_or("Invalid cursor position")?,
+                            position[1].as_f64().ok_or("Invalid cursor position")?,
+                        );
+                        self.input_capture
+                            .valid_position(point)
+                            .then_some(point)
+                            .ok_or("Cursor position is outside the capture zones")
+                    })
+                    .transpose()
+                    .map_err(|e| CommandError::new("invalid_capture", e))?;
+                let active = self.input_capture.active();
+                let result = if command == "input-capture-disable" {
+                    self.input_capture.disable(id)
+                } else {
+                    self.input_capture.release(
+                        id,
+                        args["activation_id"]
+                            .as_u64()
+                            .and_then(|id| u32::try_from(id).ok()),
+                    )
+                };
+                result.map_err(|e| CommandError::new("invalid_capture", e))?;
+                if active && !self.input_capture.active() {
+                    if let Some(position) = position
+                        && let Some(pointer) = self.seat.get_pointer()
+                    {
+                        pointer.set_location(position.into());
+                    }
+                    self.restore_input_capture_focus();
+                }
+            }
             "exit" => {} // The IPC worker stops the loop after writing the response.
             "request-logout" => self.request_logout_confirmation(),
             "reload-config" => self

compositor/src/main.rs

@@ -10,6 +10,7 @@ mod gestures;
 mod grabs;
 mod handlers;
 mod input;
+mod input_capture;
 mod ipc;
 mod metrics;
 mod overview;
@@ -137,6 +138,9 @@ fn main() -> Result<(), Box<dyn Error>> {
         }
         // All input/Wayland callbacks have returned, releasing seat locks.
         // Coalesce cursor changes and redraw here, never inside cursor_image.
+        if state.input_capture.restore_focus {
+            state.restore_input_capture_focus();
+        }
         let wallpaper_retry = state.wallpaper.take_retry_wakeup();
         if std::mem::take(&mut state.cursor_redraw_pending) || wallpaper_changed || wallpaper_retry
         {

compositor/src/session_lock.rs

@@ -123,6 +123,7 @@ impl SessionLockHandler for Ferese {
         }
         self.cancel_logout_confirmation();
         self.session_lock.active = true;
+        self.input_capture.disable_all();
         self.portal_session.set_locked(true);
         self.session_lock.owner = Some(confirmation.ext_session_lock().clone());
         self.session_lock.confirmation = Some(confirmation);

compositor/src/state.rs

@@ -232,6 +232,7 @@ pub struct Ferese {
     pub display_handle: DisplayHandle,
     pub loop_signal: LoopSignal,
     pub(crate) loop_handle: smithay::reexports::calloop::LoopHandle<'static, Self>,
+    pub(crate) input_capture: crate::input_capture::InputCapture,
     pub(crate) portal_session: crate::portal_session::PortalSession,
     pub space: Space<Window>,
     pub workspaces: WorkspaceSet,
@@ -453,6 +454,7 @@ impl Ferese {
             loop_signal: event_loop.get_signal(),
             loop_handle: event_loop.handle(),
             portal_session: Default::default(),
+            input_capture: Default::default(),
             space: Space::default(),
             workspaces: WorkspaceSet::new(
                 config.layout_mode,
@@ -582,6 +584,10 @@ impl Ferese {
 
         if let Some(keyboard) = self.seat.get_keyboard() {
             if keyboard_changed {
+                self.input_capture.close_all();
+                if self.input_capture.restore_focus {
+                    self.restore_input_capture_focus();
+                }
                 let options = (!config.input_settings.xkb_options.is_empty())
                     .then(|| config.input_settings.xkb_options.join(","));
 
@@ -896,6 +902,9 @@ impl Ferese {
         if self.session_lock.active {
             return self.lock_surface_under(position);
         }
+        if self.input_capture.active() {
+            return None;
+        }
         self.layer_surface_under(position, &[Layer::Overlay, Layer::Top])
             .map(|(_, surface, origin)| (surface, origin))
             .or_else(|| self.window_surface_under(position))
@@ -1594,6 +1603,7 @@ impl Ferese {
     }
 
     pub fn relayout(&mut self) {
+        self.refresh_input_capture_zones();
         let visible_workspaces = self.visible_workspace_ids();
         self.prune_empty_workspaces(&visible_workspaces);
         if self.session_lock.active {
@@ -2428,6 +2438,9 @@ impl Ferese {
     }
 
     fn focus_direction_with_slide(&mut self, direction: Direction, slide: bool) {
+        if self.input_capture.captures(1) {
+            return;
+        }
         if self.focus_overview_direction(direction) {
             return;
         }
@@ -3007,6 +3020,9 @@ impl Ferese {
     }
 
     pub(crate) fn restore_keyboard_focus(&mut self) {
+        if self.input_capture.captures(1) {
+            return;
+        }
         if self.session_lock.active {
             self.focus_lock_surface();
             return;

compositor/src/winit.rs

@@ -2863,6 +2863,9 @@ fn cursor_elements(
     output_geometry: Rectangle<i32, Logical>,
     scale: f64,
 ) -> Vec<AnimatedWindowRenderElement> {
+    if state.input_capture.active() {
+        return Vec::new();
+    }
     let Some(pointer) = state.seat.get_pointer() else {
         return Vec::new();
     };

docs/portals.md

@@ -47,13 +47,20 @@ standard file, print and application dialogs. Install both backends.
   for acknowledgements for up to one second. Power confirmations list blockers
   and recheck them before acting; authentication failure cancels the query.
   UserSwitch is recorded, but Ferese currently has no user-switch operation.
+- **InputCapture:** approved keyboard and pointer capture over a private EIS
+  connection, with standard screen zones and pointer barriers on outside display
+  edges. Capture begins at a configured barrier; releasing it restores local
+  input. Ctrl+Alt+Escape returns control immediately. Locking, topology/keymap
+  changes, receiver disconnects and stalled consumers stop capture. Permission
+  is requested for every session; touch capture and remembered grants are not
+  offered. This is an input receiver, not remote input injection.
 - **ScreenCast:** monitor and isolated window sharing with a native picker, PipeWire streams and explicit opt-in
   saved permissions. The frontend stores and revokes saved choices. Invalid
   restore data or changed display identity requires fresh consent.
   See [screen sharing](screen-sharing.md) for lifetime and recording details.
 
 Native request dialogs use Ferese's theme and are floating windows. Screenshot,
-PickColor, Wallpaper, USB and ScreenCast consent dialogs use Wayland parent identifiers to establish
+PickColor, Wallpaper, USB, InputCapture and ScreenCast consent dialogs use Wayland parent identifiers to establish
 a transient relationship with the requesting window.
 Cancelling a request or losing the portal frontend terminates its pending helper.
 
@@ -80,7 +87,7 @@ Matching D-Bus signatures does not establish complete feature parity.
 | GlobalShortcuts | Native sessions, configurable keyboard triggers, conflict checks and activation/release signals |
 | RemoteDesktop | Deferred: authorized input injection and EIS transport |
 | Clipboard | Deferred with RemoteDesktop |
-| InputCapture | Missing zones, pointer barriers and EIS transport |
+| InputCapture | Native v2 keyboard/pointer consent, zones, outside-edge barriers and private EIS receiver transport |
 | Lockdown | Native seven-property policy provider with persisted configuration and change signals |
 | Inhibit | Native inhibitors and session monitors; UserSwitch recorded until a switch operation exists |
 
@@ -95,8 +102,7 @@ only to the native portal executable and checks session opt-in and locking.
 Window resizing renegotiates PipeWire video dimensions. Closing the selected
 window ends sharing; its lifetime ID cannot select a replacement app. Window
 selections require fresh consent and are not saved as display permissions.
-InputCapture still needs native zones, barriers and EIS transport. RemoteDesktop
-and its Clipboard integration remain deferred.
+RemoteDesktop and its Clipboard integration remain deferred.
 
 ## Validation
 
@@ -155,3 +161,14 @@ closure using a disposable nested compositor and a real PipeWire consumer:
 ```sh
 FERESE_TEST_WINDOW_STREAM=1 python3 scripts/tests/test_window_stream_isolated.py
 ```
+
+Check InputCapture state and its transport against an installed libei receiver:
+
+```sh
+cargo test --locked -p ferese input_capture::tests
+cargo test --locked -p xdg-desktop-portal-ferese eis::tests -- --ignored
+```
+
+The receiver test uses a private socket pair and synthetic input; it never
+captures the host keyboard or changes host focus. Real pointer-barrier crossings
+and interactive consent still need a live session check.

packaging/portal/ferese-portals.conf

@@ -9,3 +9,4 @@ org.freedesktop.impl.portal.Usb=ferese;
 org.freedesktop.impl.portal.Lockdown=ferese;
 org.freedesktop.impl.portal.GlobalShortcuts=ferese;
 org.freedesktop.impl.portal.Inhibit=ferese;
+org.freedesktop.impl.portal.InputCapture=ferese;

packaging/portal/ferese.portal

@@ -1,4 +1,4 @@
 [portal]
 DBusName=org.freedesktop.impl.portal.desktop.ferese
-Interfaces=org.freedesktop.impl.portal.ScreenCast;org.freedesktop.impl.portal.Settings;org.freedesktop.impl.portal.Screenshot;org.freedesktop.impl.portal.Wallpaper;org.freedesktop.impl.portal.Background;org.freedesktop.impl.portal.Usb;org.freedesktop.impl.portal.Lockdown;org.freedesktop.impl.portal.GlobalShortcuts;org.freedesktop.impl.portal.Inhibit;
+Interfaces=org.freedesktop.impl.portal.ScreenCast;org.freedesktop.impl.portal.Settings;org.freedesktop.impl.portal.Screenshot;org.freedesktop.impl.portal.Wallpaper;org.freedesktop.impl.portal.Background;org.freedesktop.impl.portal.Usb;org.freedesktop.impl.portal.Lockdown;org.freedesktop.impl.portal.GlobalShortcuts;org.freedesktop.impl.portal.Inhibit;org.freedesktop.impl.portal.InputCapture;
 UseIn=Ferese;

portal/Cargo.toml

@@ -14,6 +14,8 @@ name = "ferese-record"
 path = "src/record_main.rs"
 
 [dependencies]
+reis = { version = "0.7.1", features = ["calloop"] }
+calloop.workspace = true
 ferese-protocols = { path = "../crates/ferese-protocols", default-features = false, features = ["client"] }
 ferese-ipc = { path = "../crates/ferese-ipc" }
 url = "2.5"

portal/src/backend.rs

@@ -54,12 +54,15 @@ pub(crate) struct Cancel {
 impl Cancel {
     pub(crate) fn stop(&self) {
         self.stopped.store(true, Ordering::SeqCst);
-        self.changed.notify_one();
+        self.changed.notify_waiters();
     }
 
     pub(crate) async fn wait(&self) {
+        let changed = self.changed.notified();
+        tokio::pin!(changed);
+        changed.as_mut().enable();
         if !self.stopped.load(Ordering::SeqCst) {
-            self.changed.notified().await;
+            changed.await;
         }
     }
 }
@@ -912,6 +915,7 @@ pub async fn run() -> Result<(), Box<dyn std::error::Error>> {
     let lockdown = crate::lockdown::Lockdown::new();
     let shortcuts = crate::shortcuts::GlobalShortcuts::new(requests.clone());
     let inhibit = crate::inhibit::Inhibit::default();
+    let input_capture = crate::input_capture::InputCapture::new(requests.clone());
     let connection = zbus::connection::Builder::session()?
         .name("org.freedesktop.impl.portal.desktop.ferese")?
         .serve_at(PATH, backend.clone())?
@@ -923,6 +927,7 @@ pub async fn run() -> Result<(), Box<dyn std::error::Error>> {
         .serve_at(PATH, lockdown.clone())?
         .serve_at(PATH, shortcuts.clone())?
         .serve_at(PATH, inhibit.clone())?
+        .serve_at(PATH, input_capture.clone())?
         .serve_at(
             "/org/ferese/ScreenRecorder",
             RecorderControl(backend.clone()),
@@ -950,6 +955,9 @@ pub async fn run() -> Result<(), Box<dyn std::error::Error>> {
         requests.revoke_stale(owner.as_deref()).await;
         shortcuts.revoke_stale(&connection, owner.as_deref()).await;
         inhibit.revoke_stale(&connection, owner.as_deref()).await;
+        input_capture
+            .revoke_stale(&connection, owner.as_deref())
+            .await;
 
         let stale: Vec<_> = backend
             .sessions

portal/src/bridge.rs

@@ -72,6 +72,15 @@ impl Bridge {
         .map_err(|error| error.to_string())?
     }
 
+    pub(crate) async fn capture_watch(&self, session: u64) -> Result<Json, String> {
+        self.request(
+            "input-capture-watch",
+            serde_json::json!({"session":session}),
+            true,
+        )
+        .await
+    }
+
     pub(crate) async fn closed(&self) {
         use std::io::Read;
         let Ok(reader) = self.0.shutdown.try_clone() else {

portal/src/eis.rs

@@ -0,0 +1,471 @@
+use std::{
+    fs::File,
+    io::Write,
+    os::{
+        fd::{AsFd, OwnedFd},
+        unix::net::UnixStream,
+    },
+    sync::{
+        Arc,
+        atomic::{AtomicBool, Ordering},
+    },
+};
+
+use calloop::{EventLoop, LoopSignal, PostAction, channel};
+use reis::{
+    calloop::{EisRequestSource, EisRequestSourceEvent},
+    eis,
+    enumflags2::BitFlags,
+    request::{Connection, Device, DeviceCapability, EisRequest},
+};
+use serde_json::Value;
+
+use crate::backend::Cancel;
+
+pub(crate) struct Worker {
+    sender: channel::SyncSender<Vec<Value>>,
+    signal: LoopSignal,
+    pub(crate) ready: Arc<AtomicBool>,
+}
+
+impl Worker {
+    pub(crate) fn start(
+        capabilities: u32,
+        keymap: &str,
+        cancel: Arc<Cancel>,
+    ) -> Result<(Self, OwnedFd), String> {
+        if keymap.is_empty() || keymap.len() > 256 * 1024 {
+            return Err("Invalid captured keyboard map".into());
+        }
+        let mut keymap_file = tempfile::tempfile().map_err(|e| e.to_string())?;
+        keymap_file
+            .write_all(keymap.as_bytes())
+            .and_then(|_| keymap_file.write_all(&[0]))
+            .map_err(|e| e.to_string())?;
+        let keymap_size = keymap.len() as u32 + 1;
+        let (server, client) = UnixStream::pair().map_err(|e| e.to_string())?;
+        let ready = Arc::new(AtomicBool::new(false));
+        let thread_ready = ready.clone();
+        let (startup, started) = std::sync::mpsc::sync_channel(1);
+        std::thread::Builder::new()
+            .name("ferese-input-eis".into())
+            .spawn(move || {
+                struct Finish(Arc<Cancel>);
+                impl Drop for Finish {
+                    fn drop(&mut self) {
+                        self.0.stop();
+                    }
+                }
+                let _finish = Finish(cancel);
+                let run = || {
+                    let context = eis::Context::new(server).map_err(|e| e.to_string())?;
+                    let mut event_loop =
+                        EventLoop::<State>::try_new().map_err(|e| e.to_string())?;
+                    let signal = event_loop.get_signal();
+                    let (sender, receiver) = channel::sync_channel(4);
+                    event_loop
+                        .handle()
+                        .insert_source(receiver, |event, _, state| match event {
+                            channel::Event::Msg(events) => state.events(events),
+                            channel::Event::Closed => state.signal.stop(),
+                        })
+                        .map_err(|e| e.to_string())?;
+                    event_loop
+                        .handle()
+                        .insert_source(
+                            EisRequestSource::new(context, 1),
+                            |event, connection, state| {
+                                let action = match event {
+                                    Ok(event) => state.request(connection, event),
+                                    Err(_) => {
+                                        state.signal.stop();
+                                        PostAction::Remove
+                                    }
+                                };
+                                if connection.flush().is_err() {
+                                    state.signal.stop();
+                                }
+                                Ok(action)
+                            },
+                        )
+                        .map_err(|e| e.to_string())?;
+                    let mut state = State {
+                        signal: signal.clone(),
+                        ready: thread_ready.clone(),
+                        capabilities,
+                        keymap: keymap_file,
+                        keymap_size,
+                        connection: None,
+                        keyboard: None,
+                        pointer: None,
+                        activation: None,
+                        keyboard_ready: false,
+                        pointer_ready: false,
+                    };
+                    startup
+                        .send(Ok((sender, signal)))
+                        .map_err(|_| "Input transport startup cancelled".to_owned())?;
+                    let _ = event_loop.run(None, &mut state, |_| {});
+                    if let Some(connection) = state.connection.take() {
+                        connection
+                            .disconnected(eis::connection::DisconnectReason::Disconnected, None);
+                    }
+                    state.ready.store(false, Ordering::SeqCst);
+                    Ok::<(), String>(())
+                };
+                if let Err(error) = run() {
+                    let _ = startup.send(Err(error));
+                }
+            })
+            .map_err(|e| e.to_string())?;
+        let (sender, signal) = started
+            .recv_timeout(std::time::Duration::from_secs(2))
+            .map_err(|_| "Input transport startup timed out".to_owned())??;
+        Ok((
+            Self {
+                sender,
+                signal,
+                ready,
+            },
+            client.into(),
+        ))
+    }
+
+    pub(crate) fn send(&self, events: Vec<Value>) -> Result<(), String> {
+        self.sender
+            .try_send(events)
+            .map_err(|_| "Input transport is closed or stalled".into())
+    }
+
+    pub(crate) fn stop(&self) {
+        self.signal.stop();
+        self.signal.wakeup();
+    }
+}
+
+impl Drop for Worker {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+struct State {
+    signal: LoopSignal,
+    ready: Arc<AtomicBool>,
+    capabilities: u32,
+    keymap: File,
+    keymap_size: u32,
+    connection: Option<Connection>,
+    keyboard: Option<Device>,
+    pointer: Option<Device>,
+    activation: Option<u32>,
+    keyboard_ready: bool,
+    pointer_ready: bool,
+}
+
+impl State {
+    fn request(&mut self, connection: &Connection, event: EisRequestSourceEvent) -> PostAction {
+        match event {
+            EisRequestSourceEvent::Connected => {
+                if connection.context_type() != eis::handshake::ContextType::Receiver {
+                    connection.disconnected(
+                        eis::connection::DisconnectReason::Mode,
+                        Some("Input capture requires a receiver context"),
+                    );
+                    self.signal.stop();
+                    return PostAction::Remove;
+                }
+                let mut capabilities = BitFlags::<DeviceCapability>::empty();
+                if self.capabilities & 1 != 0 {
+                    capabilities |= DeviceCapability::Keyboard;
+                }
+                if self.capabilities & 2 != 0 {
+                    capabilities |= DeviceCapability::Pointer
+                        | DeviceCapability::Button
+                        | DeviceCapability::Scroll;
+                }
+                let _ = connection.add_seat(Some("Ferese input capture"), capabilities);
+                self.connection = Some(connection.clone());
+            }
+            EisRequestSourceEvent::Request(EisRequest::Bind(request)) => {
+                let keyboard = request.capabilities.contains(DeviceCapability::Keyboard)
+                    && self.capabilities & 1 != 0;
+                let pointer = request.capabilities.contains(DeviceCapability::Pointer)
+                    && self.capabilities & 2 != 0;
+                if !keyboard && let Some(device) = self.keyboard.take() {
+                    device.remove();
+                    self.keyboard_ready = false;
+                }
+                if !pointer && let Some(device) = self.pointer.take() {
+                    device.remove();
+                    self.pointer_ready = false;
+                }
+                if keyboard && self.keyboard.is_none() {
+                    let device = request.seat.add_device(
+                        Some("Ferese keyboard"),
+                        eis::device::DeviceType::Virtual,
+                        DeviceCapability::Keyboard.into(),
+                        |device| {
+                            if let Some(keyboard) = device.interface::<eis::Keyboard>() {
+                                keyboard.keymap(
+                                    eis::keyboard::KeymapType::Xkb,
+                                    self.keymap_size,
+                                    self.keymap.as_fd(),
+                                );
+                            }
+                        },
+                    );
+                    self.keyboard_ready = device.device().version() < 3;
+                    device.resumed();
+                    self.keyboard = Some(device);
+                }
+                if pointer && self.pointer.is_none() {
+                    let caps = request.capabilities
+                        & (DeviceCapability::Pointer
+                            | DeviceCapability::Button
+                            | DeviceCapability::Scroll);
+                    let device = request.seat.add_device(
+                        Some("Ferese pointer"),
+                        eis::device::DeviceType::Virtual,
+                        caps,
+                        |_| {},
+                    );
+                    self.pointer_ready = device.device().version() < 3;
+                    device.resumed();
+                    self.pointer = Some(device);
+                }
+                let ready = self.keyboard.is_some() || self.pointer.is_some();
+                self.ready.store(
+                    ready
+                        && (self.keyboard.is_none() || self.keyboard_ready)
+                        && (self.pointer.is_none() || self.pointer_ready),
+                    Ordering::SeqCst,
+                );
+                if self.activation.is_some() || !ready {
+                    self.signal.stop();
+                }
+            }
+            EisRequestSourceEvent::Request(EisRequest::Ready(request)) => {
+                if self
+                    .keyboard
+                    .as_ref()
+                    .is_some_and(|device| device.device() == request.device.device())
+                {
+                    self.keyboard_ready = true;
+                } else if self
+                    .pointer
+                    .as_ref()
+                    .is_some_and(|device| device.device() == request.device.device())
+                {
+                    self.pointer_ready = true;
+                } else {
+                    self.signal.stop();
+                    return PostAction::Remove;
+                }
+                self.ready.store(
+                    (self.keyboard.is_none() || self.keyboard_ready)
+                        && (self.pointer.is_none() || self.pointer_ready),
+                    Ordering::SeqCst,
+                );
+            }
+            EisRequestSourceEvent::Request(
+                EisRequest::Disconnect | EisRequest::DeviceClosed(_),
+            ) => {
+                self.signal.stop();
+                return PostAction::Remove;
+            }
+            EisRequestSourceEvent::Request(_) => {
+                connection.disconnected(
+                    eis::connection::DisconnectReason::Mode,
+                    Some("Input capture does not accept injected input"),
+                );
+                self.signal.stop();
+                return PostAction::Remove;
+            }
+        }
+        PostAction::Continue
+    }
+
+    fn events(&mut self, events: Vec<Value>) {
+        for event in events {
+            match event["type"].as_str() {
+                Some("activated") => {
+                    let activation = event["activation_id"].as_u64().unwrap_or(0) as u32;
+                    self.activation = Some(activation);
+                    for device in [&self.keyboard, &self.pointer].into_iter().flatten() {
+                        device.start_emulating(activation);
+                    }
+                }
+                Some("deactivated" | "disabled" | "closed") => {
+                    if self.activation.take().is_some() {
+                        for device in [&self.keyboard, &self.pointer].into_iter().flatten() {
+                            device.stop_emulating();
+                        }
+                    }
+                }
+                Some("keys") if self.activation.is_some() => {
+                    if let Some(device) = &self.keyboard
+                        && let Some(keyboard) = device.interface::<eis::Keyboard>()
+                    {
+                        for key in event["keys"]
+                            .as_array()
+                            .into_iter()
+                            .flatten()
+                            .filter_map(Value::as_u64)
+                        {
+                            keyboard.key(key as u32, eis::keyboard::KeyState::Press);
+                        }
+                        device.frame(now());
+                    }
+                }
+                Some("key") if self.activation.is_some() => {
+                    if let Some(device) = &self.keyboard
+                        && let Some(keyboard) = device.interface::<eis::Keyboard>()
+                    {
+                        keyboard.key(
+                            event["key"].as_u64().unwrap_or(0) as u32,
+                            if event["pressed"] == true {
+                                eis::keyboard::KeyState::Press
+                            } else {
+                                eis::keyboard::KeyState::Released
+                            },
+                        );
+                        device.frame(now());
+                    }
+                }
+                Some("motion" | "button" | "scroll") if self.activation.is_some() => {
+                    if let Some(device) = &self.pointer {
+                        match event["type"].as_str() {
+                            Some("motion") => {
+                                if let Some(pointer) = device.interface::<eis::Pointer>() {
+                                    pointer.motion_relative(
+                                        event["x"].as_f64().unwrap_or(0.0) as f32,
+                                        event["y"].as_f64().unwrap_or(0.0) as f32,
+                                    );
+                                }
+                            }
+                            Some("button") => {
+                                if let Some(button) = device.interface::<eis::Button>() {
+                                    button.button(
+                                        event["button"].as_u64().unwrap_or(0) as u32,
+                                        if event["pressed"] == true {
+                                            eis::button::ButtonState::Press
+                                        } else {
+                                            eis::button::ButtonState::Released
+                                        },
+                                    );
+                                }
+                            }
+                            Some("scroll") => {
+                                if let Some(scroll) = device.interface::<eis::Scroll>() {
+                                    let x = event["x"].as_f64().unwrap_or(0.0) as f32;
+                                    let y = event["y"].as_f64().unwrap_or(0.0) as f32;
+                                    if !event["v120_x"].is_null() || !event["v120_y"].is_null() {
+                                        scroll.scroll_discrete(
+                                            event["v120_x"].as_f64().unwrap_or(0.0) as i32,
+                                            event["v120_y"].as_f64().unwrap_or(0.0) as i32,
+                                        );
+                                    } else if x != 0.0 || y != 0.0 {
+                                        scroll.scroll(x, y);
+                                    }
+                                    let stop_x = event["stop_x"] == true;
+                                    let stop_y = event["stop_y"] == true;
+                                    if stop_x || stop_y {
+                                        scroll.scroll_stop(stop_x as u32, stop_y as u32, 0);
+                                    }
+                                }
+                            }
+                            _ => (),
+                        }
+                        device.frame(now());
+                    }
+                }
+                _ => (),
+            }
+        }
+        if let Some(connection) = &self.connection
+            && connection.flush().is_err()
+        {
+            self.signal.stop();
+        }
+    }
+}
+
+fn now() -> u64 {
+    let mut time = libc::timespec {
+        tv_sec: 0,
+        tv_nsec: 0,
+    };
+    // SAFETY: the initialized output pointer covers a timespec allocation.
+    if unsafe { libc::clock_gettime(libc::CLOCK_MONOTONIC, &mut time) } == 0 {
+        time.tv_sec as u64 * 1_000_000 + time.tv_nsec as u64 / 1_000
+    } else {
+        0
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+    use std::{
+        process::{Command, Stdio},
+        time::{Duration, Instant},
+    };
+
+    #[test]
+    #[ignore = "requires Python and the system libei receiver library"]
+    fn libei_receives_keymap_motion_keyboard_and_explicit_axis_stop() {
+        let cancel = Arc::new(Cancel::default());
+        let map = "xkb_keymap { xkb_keycodes { include \"evdev+aliases(qwerty)\" }; xkb_types { include \"complete\" }; xkb_compatibility { include \"complete\" }; xkb_symbols { include \"pc+us+inet(evdev)\" }; };";
+        let (worker, fd) = Worker::start(3, map, cancel.clone()).unwrap();
+        let fixture = std::path::Path::new(env!("CARGO_MANIFEST_DIR"))
+            .join("../scripts/tests/fixtures/eis-receiver.py");
+        let mut client = Command::new("python3")
+            .arg(fixture)
+            .stdin(Stdio::from(fd))
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .spawn()
+            .unwrap();
+        let deadline = Instant::now() + Duration::from_secs(5);
+        while !worker.ready.load(Ordering::SeqCst) && Instant::now() < deadline {
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        if !worker.ready.load(Ordering::SeqCst) {
+            let _ = client.kill();
+            let output = client.wait_with_output().unwrap();
+            panic!(
+                "Receiver did not bind: {}",
+                String::from_utf8_lossy(&output.stderr)
+            );
+        }
+        worker
+            .send(vec![
+                json!({"type":"activated", "activation_id":1}),
+                json!({"type":"motion", "x":10.0, "y":-5.0}),
+                json!({"type":"motion", "x":10.0, "y":-5.0}),
+                json!({"type":"key", "key":30, "pressed":true}),
+                json!({"type":"key", "key":30, "pressed":false}),
+                json!({"type":"scroll", "x":0.0, "y":4.0}),
+                json!({"type":"scroll", "x":0.0, "y":0.0, "stop_x":false, "stop_y":true}),
+                json!({"type":"deactivated"}),
+            ])
+            .unwrap();
+        let output = client.wait_with_output().unwrap();
+        assert!(
+            output.status.success(),
+            "{}",
+            String::from_utf8_lossy(&output.stderr)
+        );
+        assert!(String::from_utf8_lossy(&output.stdout).contains("\"keymap\": true"));
+        let deadline = Instant::now() + Duration::from_secs(2);
+        while !cancel.stopped.load(Ordering::SeqCst) && Instant::now() < deadline {
+            std::thread::sleep(Duration::from_millis(10));
+        }
+        assert!(
+            cancel.stopped.load(Ordering::SeqCst),
+            "Receiver disconnect must revoke capture"
+        );
+    }
+}

portal/src/input_capture.rs

@@ -0,0 +1,784 @@
+use std::{
+    collections::HashMap,
+    sync::{Arc, atomic::Ordering},
+    time::Duration,
+};
+
+use serde_json::json;
+use tokio::sync::Mutex;
+use zbus::{
+    Connection,
+    message::Header,
+    object_server::SignalEmitter,
+    zvariant::{OwnedFd, OwnedObjectPath, Value},
+};
+
+use crate::{
+    backend::{Cancel, Options, authorize},
+    bridge::Bridge,
+    desktop::Requests,
+    eis::Worker,
+};
+
+const PATH: &str = "/org/freedesktop/portal/desktop";
+
+#[derive(Default)]
+struct State {
+    starting: bool,
+    started: bool,
+    id: u64,
+    capabilities: u32,
+    keymap: String,
+    bridge: Option<Bridge>,
+    watch: Option<Bridge>,
+    worker: Option<Worker>,
+}
+
+struct Session {
+    owner: String,
+    app: String,
+    cancel: Arc<Cancel>,
+    state: Mutex<State>,
+}
+
+#[derive(Clone, Default)]
+pub(crate) struct InputCapture {
+    sessions: Arc<Mutex<HashMap<String, Arc<Session>>>>,
+    requests: Requests,
+}
+
+impl InputCapture {
+    pub(crate) fn new(requests: Requests) -> Self {
+        Self {
+            requests,
+            ..Self::default()
+        }
+    }
+
+    async fn session(
+        &self,
+        connection: &Connection,
+        header: &Header<'_>,
+        path: &OwnedObjectPath,
+        app: &str,
+    ) -> zbus::fdo::Result<Arc<Session>> {
+        let owner = authorize(connection, header).await?;
+        self.sessions
+            .lock()
+            .await
+            .get(path.as_str())
+            .filter(|session| session.owner == owner && session.app == app)
+            .cloned()
+            .ok_or_else(|| invalid("Unknown input capture session"))
+    }
+
+    async fn end(&self, connection: &Connection, path: &str) {
+        let session = self.sessions.lock().await.remove(path);
+        if let Some(session) = session {
+            session.cancel.stop();
+            let state = session.state.lock().await;
+            if let Some(worker) = &state.worker {
+                worker.stop();
+            }
+            if let Some(bridge) = &state.bridge {
+                bridge.close();
+            }
+            if let Some(watch) = &state.watch {
+                watch.close();
+            }
+            if let Ok(emitter) = SignalEmitter::new(connection, path) {
+                let _ = SessionObject::closed(&emitter).await;
+            }
+            let connection = connection.clone();
+            let path = path.to_owned();
+            tokio::spawn(async move {
+                let _ = connection
+                    .object_server()
+                    .remove::<SessionObject, _>(path)
+                    .await;
+            });
+        }
+    }
+
+    pub(crate) async fn revoke_stale(&self, connection: &Connection, owner: Option<&str>) {
+        let stale = self
+            .sessions
+            .lock()
+            .await
+            .iter()
+            .filter_map(|(path, session)| {
+                (Some(session.owner.as_str()) != owner).then_some(path.clone())
+            })
+            .collect::<Vec<_>>();
+        for path in stale {
+            self.end(connection, &path).await;
+        }
+    }
+
+    async fn native(session: &Session) -> zbus::fdo::Result<(Bridge, u64)> {
+        let state = session.state.lock().await;
+        if !state.started || session.cancel.stopped.load(Ordering::SeqCst) {
+            return Err(invalid("Start the session first"));
+        }
+        Ok((
+            state
+                .bridge
+                .clone()
+                .ok_or_else(|| invalid("Missing capture connection"))?,
+            state.id,
+        ))
+    }
+
+    async fn watch(
+        self,
+        connection: Connection,
+        path: OwnedObjectPath,
+        session: Arc<Session>,
+        bridge: Bridge,
+        id: u64,
+    ) {
+        loop {
+            let response = tokio::select! {
+                _ = session.cancel.wait() => break,
+                result = bridge.capture_watch(id) => result,
+            };
+            let Ok(response) = response else {
+                break;
+            };
+            let Some(events) = response["events"].as_array() else {
+                break;
+            };
+            let state = session.state.lock().await;
+            if session.cancel.stopped.load(Ordering::SeqCst) {
+                break;
+            }
+            let transport = state
+                .worker
+                .as_ref()
+                .map(|worker| worker.send(events.clone()));
+            if transport.is_some_and(|result| result.is_err()) {
+                break;
+            }
+            let mut closed = false;
+            let Ok(emitter) = SignalEmitter::new(&connection, PATH) else {
+                break;
+            };
+            for event in events {
+                let result = match event["type"].as_str() {
+                    Some("activated") => {
+                        let mut options = Options::new();
+                        options.insert(
+                            "activation_id".into(),
+                            (event["activation_id"].as_u64().unwrap_or(0) as u32).into(),
+                        );
+                        options.insert(
+                            "barrier_id".into(),
+                            (event["barrier_id"].as_u64().unwrap_or(0) as u32).into(),
+                        );
+                        if let Some(position) = event["cursor_position"]
+                            .as_array()
+                            .filter(|position| position.len() == 2)
+                        {
+                            if let Ok(position) = Value::from((
+                                position[0].as_f64().unwrap_or(0.0),
+                                position[1].as_f64().unwrap_or(0.0),
+                            ))
+                            .try_to_owned()
+                            {
+                                options.insert("cursor_position".into(), position);
+                            }
+                        }
+                        Self::activated(&emitter, path.clone(), options).await
+                    }
+                    Some("deactivated") => {
+                        Self::deactivated(
+                            &emitter,
+                            path.clone(),
+                            Options::from([(
+                                "activation_id".into(),
+                                (event["activation_id"].as_u64().unwrap_or(0) as u32).into(),
+                            )]),
+                        )
+                        .await
+                    }
+                    Some("disabled") => {
+                        Self::disabled(&emitter, path.clone(), Options::new()).await
+                    }
+                    Some("zones") => {
+                        Self::zones_changed(&emitter, path.clone(), Options::new()).await
+                    }
+                    Some("closed") => {
+                        closed = true;
+                        Ok(())
+                    }
+                    _ => Ok(()),
+                };
+                if result.is_err() {
+                    closed = true;
+                }
+            }
+            drop(state);
+            if closed {
+                break;
+            }
+        }
+        self.end(&connection, path.as_str()).await;
+    }
+}
+
+fn invalid(message: &str) -> zbus::fdo::Error {
+    zbus::fdo::Error::InvalidArgs(message.into())
+}
+
+fn failed(error: String) -> zbus::fdo::Error {
+    zbus::fdo::Error::Failed(error)
+}
+
+fn capabilities(options: &Options) -> zbus::fdo::Result<u32> {
+    let requested = options
+        .get("capabilities")
+        .ok_or_else(|| invalid("Missing requested capabilities"))?;
+    let requested =
+        u32::try_from(requested).map_err(|_| invalid("Invalid requested capabilities"))?;
+    if requested == 0 || requested & 3 == 0 {
+        return Err(invalid("No supported capabilities requested"));
+    }
+    Ok(requested & 3)
+}
+
+#[zbus::interface(name = "org.freedesktop.impl.portal.InputCapture")]
+impl InputCapture {
+    #[zbus(property, name = "version")]
+    fn version(&self) -> u32 {
+        2
+    }
+
+    #[zbus(property)]
+    fn supported_capabilities(&self) -> u32 {
+        3
+    }
+
+    async fn create_session2(
+        &self,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        _options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<Options> {
+        let owner = authorize(connection, &header).await?;
+        if !session_handle
+            .as_str()
+            .starts_with(&format!("{PATH}/session/"))
+            || session_handle.as_str().len() > 512
+            || app_id.len() > 512
+        {
+            return Err(invalid("Invalid session"));
+        }
+        let mut sessions = self.sessions.lock().await;
+        if sessions.len() >= 8 || sessions.contains_key(session_handle.as_str()) {
+            return Err(invalid("Session limit reached or duplicate session"));
+        }
+        if !connection
+            .object_server()
+            .at(
+                &session_handle,
+                SessionObject {
+                    backend: self.clone(),
+                    path: session_handle.to_string(),
+                    owner: owner.clone(),
+                },
+            )
+            .await?
+        {
+            return Err(invalid("Session object already exists"));
+        }
+        sessions.insert(
+            session_handle.to_string(),
+            Arc::new(Session {
+                owner,
+                app: app_id,
+                cancel: Arc::default(),
+                state: Mutex::default(),
+            }),
+        );
+        Ok(Options::new())
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    async fn create_session(
+        &self,
+        handle: OwnedObjectPath,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        parent_window: String,
+        options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        capabilities(&options)?;
+        self.create_session2(
+            session_handle.clone(),
+            app_id.clone(),
+            Options::new(),
+            connection,
+            header.clone(),
+        )
+        .await?;
+        let result = self
+            .start(
+                handle,
+                session_handle.clone(),
+                app_id,
+                parent_window,
+                options,
+                connection,
+                header,
+            )
+            .await;
+        let (response, mut results) = match result {
+            Ok(result) => result,
+            Err(error) => {
+                self.end(connection, session_handle.as_str()).await;
+                return Err(error);
+            }
+        };
+        if response == 0 {
+            results.insert(
+                "session_id".into(),
+                Value::from(session_handle.to_string())
+                    .try_to_owned()
+                    .map_err(|e| failed(e.to_string()))?,
+            );
+        }
+        Ok((response, results))
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    async fn start(
+        &self,
+        handle: OwnedObjectPath,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        parent_window: String,
+        options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        let caps = capabilities(&options)?;
+        crate::restore::persist_mode(&options)?;
+        let cancel = self.requests.begin(connection, &header, &handle).await?;
+        {
+            let mut state = session.state.lock().await;
+            if state.starting || state.started {
+                self.requests.end(connection, &handle).await;
+                return Err(invalid("Input capture can only be started once"));
+            }
+            state.starting = true;
+        }
+        let title = match caps {
+            1 => "Share keyboard input?",
+            2 => "Share pointer input?",
+            _ => "Share keyboard and pointer?",
+        };
+        let consent = crate::desktop::consent(
+            &app_id,
+            &parent_window,
+            title,
+            "Allow input capture at the screen edges this app configures. Captured input is sent to this app until it releases control. Press Ctrl+Alt+Escape to return control to Ferese.",
+            "Allow input capture",
+            None,
+        );
+        let approved = tokio::select! {
+            _ = cancel.wait() => Ok(false),
+            _ = session.cancel.wait() => Ok(false),
+            result = consent => result,
+        };
+        let result = if approved == Ok(true)
+            && !cancel.stopped.load(Ordering::SeqCst)
+            && !session.cancel.stopped.load(Ordering::SeqCst)
+        {
+            async {
+                let bridge = Bridge::connect()?;
+                let reply = bridge
+                    .call("input-capture-register", json!({"capabilities":caps}))
+                    .await?;
+                let id = reply["session"]
+                    .as_u64()
+                    .ok_or("Missing capture session ID")?;
+                let keymap = reply["keymap"]
+                    .as_str()
+                    .ok_or("Missing keyboard map")?
+                    .to_owned();
+                let watch = Bridge::connect()?;
+                let mut state = session.state.lock().await;
+                if cancel.stopped.load(Ordering::SeqCst)
+                    || session.cancel.stopped.load(Ordering::SeqCst)
+                {
+                    bridge.close();
+                    return Err("Input capture approval was cancelled".to_owned());
+                }
+                state.started = true;
+                state.starting = false;
+                state.id = id;
+                state.capabilities = caps;
+                state.keymap = keymap;
+                state.bridge = Some(bridge);
+                state.watch = Some(watch.clone());
+                tokio::spawn(self.clone().watch(
+                    connection.clone(),
+                    session_handle.clone(),
+                    session.clone(),
+                    watch,
+                    id,
+                ));
+                Ok(Options::from([
+                    ("capabilities".into(), caps.into()),
+                    ("clipboard_enabled".into(), false.into()),
+                    ("persist_mode".into(), 0u32.into()),
+                ]))
+            }
+            .await
+        } else {
+            Err(approved.err().unwrap_or_else(|| "Cancelled".into()))
+        };
+        self.requests.end(connection, &handle).await;
+        match result {
+            Ok(results) => Ok((0, results)),
+            Err(error) => {
+                let response = if error == "Cancelled"
+                    || cancel.stopped.load(Ordering::SeqCst)
+                    || session.cancel.stopped.load(Ordering::SeqCst)
+                {
+                    1
+                } else {
+                    eprintln!("ferese input capture: {error}");
+                    2
+                };
+                self.end(connection, session_handle.as_str()).await;
+                Ok((response, Options::new()))
+            }
+        }
+    }
+
+    async fn get_zones(
+        &self,
+        handle: OwnedObjectPath,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        _options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        let (bridge, id) = Self::native(&session).await?;
+        let cancel = self.requests.begin(connection, &header, &handle).await?;
+        let result = tokio::select! {
+            biased;
+            _ = cancel.wait() => None,
+            _ = session.cancel.wait() => None,
+            result = bridge.call("input-capture-zones", json!({"session":id})) => Some(result),
+        };
+        self.requests.end(connection, &handle).await;
+        if cancel.stopped.load(Ordering::SeqCst)
+            || session.cancel.stopped.load(Ordering::SeqCst)
+            || result.is_none()
+        {
+            return Ok((1, Options::new()));
+        }
+        let result = result.unwrap().map_err(failed)?;
+        let zones: Vec<(u32, u32, i32, i32)> = serde_json::from_value(result["zones"].clone())
+            .map_err(|_| invalid("Invalid native capture zones"))?;
+        Ok((
+            0,
+            Options::from([
+                (
+                    "zones".into(),
+                    Value::from(zones)
+                        .try_to_owned()
+                        .map_err(|e| failed(e.to_string()))?,
+                ),
+                (
+                    "zone_set".into(),
+                    (result["zone_set"].as_u64().unwrap_or(0) as u32).into(),
+                ),
+            ]),
+        ))
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    async fn set_pointer_barriers(
+        &self,
+        handle: OwnedObjectPath,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        _options: Options,
+        barriers: Vec<Options>,
+        zone_set: u32,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        let (bridge, id) = Self::native(&session).await?;
+        if barriers.len() > 64 {
+            return Err(invalid("Too many pointer barriers"));
+        }
+        let barriers = barriers
+            .into_iter()
+            .map(|barrier| {
+                let id = u32::try_from(
+                    barrier
+                        .get("barrier_id")
+                        .ok_or_else(|| invalid("Missing barrier ID"))?,
+                )
+                .map_err(|_| invalid("Invalid barrier ID"))?;
+                let position = barrier
+                    .get("position")
+                    .ok_or_else(|| invalid("Missing barrier position"))?
+                    .try_clone()
+                    .map_err(|_| invalid("Invalid position"))?;
+                let position: (i32, i32, i32, i32) = position
+                    .try_into()
+                    .map_err(|_| invalid("Invalid barrier position"))?;
+                Ok(json!({"id":id,"position":[position.0,position.1,position.2,position.3]}))
+            })
+            .collect::<zbus::fdo::Result<Vec<_>>>()?;
+        let cancel = self.requests.begin(connection, &header, &handle).await?;
+        let result = tokio::select! {
+            biased;
+            _ = cancel.wait() => None,
+            _ = session.cancel.wait() => None,
+            result = bridge.call("input-capture-barriers", json!({"session":id,"zone_set":zone_set,"barriers":barriers})) => Some(result),
+        };
+        self.requests.end(connection, &handle).await;
+        if cancel.stopped.load(Ordering::SeqCst)
+            || session.cancel.stopped.load(Ordering::SeqCst)
+            || result.is_none()
+        {
+            self.end(connection, session_handle.as_str()).await;
+            return Ok((1, Options::new()));
+        }
+        let result = result.unwrap().map_err(failed)?;
+        let failed_barriers: Vec<u32> = serde_json::from_value(result["failed_barriers"].clone())
+            .map_err(|_| invalid("Invalid native barrier response"))?;
+        Ok((
+            0,
+            Options::from([(
+                "failed_barriers".into(),
+                Value::from(failed_barriers)
+                    .try_to_owned()
+                    .map_err(|e| failed(e.to_string()))?,
+            )]),
+        ))
+    }
+
+    #[zbus(name = "ConnectToEIS")]
+    async fn connect_to_eis(
+        &self,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        _options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<OwnedFd> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        Self::native(&session).await?;
+        let mut state = session.state.lock().await;
+        if state.worker.is_some() {
+            return Err(invalid("EIS has already been connected"));
+        }
+        let capabilities = state.capabilities;
+        let keymap = state.keymap.clone();
+        let cancel = session.cancel.clone();
+        let (worker, fd) =
+            tokio::task::spawn_blocking(move || Worker::start(capabilities, &keymap, cancel))
+                .await
+                .map_err(|e| failed(e.to_string()))?
+                .map_err(failed)?;
+        state.worker = Some(worker);
+        Ok(fd.into())
+    }
+
+    async fn enable(
+        &self,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        _options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        let (bridge, id) = Self::native(&session).await?;
+        let ready = session
+            .state
+            .lock()
+            .await
+            .worker
+            .as_ref()
+            .map(|worker| worker.ready.clone())
+            .ok_or_else(|| invalid("Connect to EIS before enabling input capture"))?;
+        let deadline = tokio::time::Instant::now() + Duration::from_secs(5);
+        while !ready.load(Ordering::SeqCst) {
+            if session.cancel.stopped.load(Ordering::SeqCst)
+                || tokio::time::Instant::now() >= deadline
+            {
+                return Err(invalid("EIS receiver has not bound an input device"));
+            }
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+        bridge
+            .call("input-capture-enable", json!({"session":id}))
+            .await
+            .map_err(failed)?;
+        Ok((0, Options::new()))
+    }
+
+    async fn disable(
+        &self,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        _options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        let (bridge, id) = Self::native(&session).await?;
+        bridge
+            .call("input-capture-disable", json!({"session":id}))
+            .await
+            .map_err(failed)?;
+        Ok((0, Options::new()))
+    }
+
+    async fn release(
+        &self,
+        session_handle: OwnedObjectPath,
+        app_id: String,
+        options: Options,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<(u32, Options)> {
+        let session = self
+            .session(connection, &header, &session_handle, &app_id)
+            .await?;
+        let (bridge, id) = Self::native(&session).await?;
+        let activation = options
+            .get("activation_id")
+            .map(u32::try_from)
+            .transpose()
+            .map_err(|_| invalid("Invalid activation ID"))?;
+        let position = options
+            .get("cursor_position")
+            .map(|value| {
+                let position: (f64, f64) = value
+                    .try_clone()
+                    .map_err(|_| invalid("Invalid cursor position"))?
+                    .try_into()
+                    .map_err(|_| invalid("Invalid cursor position"))?;
+                if !position.0.is_finite() || !position.1.is_finite() {
+                    return Err(invalid("Invalid cursor position"));
+                }
+                Ok(position)
+            })
+            .transpose()?;
+        bridge
+            .call(
+                "input-capture-release",
+                json!({"session":id,"activation_id":activation,"cursor_position":position}),
+            )
+            .await
+            .map_err(failed)?;
+        Ok((0, Options::new()))
+    }
+
+    #[zbus(signal)]
+    async fn activated(
+        emitter: &SignalEmitter<'_>,
+        session_handle: OwnedObjectPath,
+        options: Options,
+    ) -> zbus::Result<()>;
+
+    #[zbus(signal)]
+    async fn deactivated(
+        emitter: &SignalEmitter<'_>,
+        session_handle: OwnedObjectPath,
+        options: Options,
+    ) -> zbus::Result<()>;
+
+    #[zbus(signal)]
+    async fn disabled(
+        emitter: &SignalEmitter<'_>,
+        session_handle: OwnedObjectPath,
+        options: Options,
+    ) -> zbus::Result<()>;
+
+    #[zbus(signal)]
+    async fn zones_changed(
+        emitter: &SignalEmitter<'_>,
+        session_handle: OwnedObjectPath,
+        options: Options,
+    ) -> zbus::Result<()>;
+}
+
+struct SessionObject {
+    backend: InputCapture,
+    path: String,
+    owner: String,
+}
+
+#[zbus::interface(name = "org.freedesktop.impl.portal.Session")]
+impl SessionObject {
+    #[zbus(property, name = "version")]
+    fn version(&self) -> u32 {
+        1
+    }
+
+    async fn close(
+        &self,
+        #[zbus(connection)] connection: &Connection,
+        #[zbus(header)] header: Header<'_>,
+    ) -> zbus::fdo::Result<()> {
+        if header.sender().map(|owner| owner.as_str()) != Some(self.owner.as_str()) {
+            return Err(zbus::fdo::Error::AccessDenied("Wrong session owner".into()));
+        }
+        self.backend.end(connection, &self.path).await;
+        Ok(())
+    }
+
+    #[zbus(signal)]
+    async fn closed(emitter: &SignalEmitter<'_>) -> zbus::Result<()>;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn requested_capabilities_are_required_and_supported_subset_is_returned() {
+        assert!(capabilities(&Options::new()).is_err());
+        for requested in [0u32, 4, 8] {
+            assert!(
+                capabilities(&Options::from([("capabilities".into(), requested.into())])).is_err()
+            );
+        }
+        for (requested, supported) in [(1u32, 1), (2, 2), (3, 3), (7, 3), (9, 1)] {
+            assert_eq!(
+                capabilities(&Options::from([("capabilities".into(), requested.into())])).unwrap(),
+                supported
+            );
+        }
+    }
+}

portal/src/main.rs

@@ -3,7 +3,9 @@ mod bridge;
 mod capture;
 mod consent;
 mod desktop;
+mod eis;
 mod inhibit;
+mod input_capture;
 mod lockdown;
 mod parent;
 mod permissions;

scripts/tests/fixtures/eis-receiver.py

@@ -0,0 +1,77 @@
+"""Receive Ferese's private test EIS connection through stdin using real libei."""
+import ctypes as C
+import ctypes.util
+import json
+import os
+import select
+import time
+
+lib = C.CDLL(ctypes.util.find_library("ei"))
+
+
+def function(name, result, *arguments):
+    value = getattr(lib, name)
+    value.restype = result
+    value.argtypes = list(arguments)
+    return value
+
+
+ptr = C.c_void_p
+new = function("ei_new_receiver", ptr, ptr)
+setup = function("ei_setup_backend_fd", C.c_int, ptr, C.c_int)
+dispatch = function("ei_dispatch", None, ptr)
+next_event = function("ei_get_event", ptr, ptr)
+kind = function("ei_event_get_type", C.c_int, ptr)
+seat = function("ei_event_get_seat", ptr, ptr)
+device = function("ei_event_get_device", ptr, ptr)
+unref_event = function("ei_event_unref", ptr, ptr)
+unref = function("ei_unref", ptr, ptr)
+bind = function("ei_seat_bind_capabilities", None, ptr)
+keymap = function("ei_device_keyboard_get_keymap", ptr, ptr)
+map_fd = function("ei_keymap_get_fd", C.c_int, ptr)
+map_size = function("ei_keymap_get_size", C.c_size_t, ptr)
+dx = function("ei_event_pointer_get_dx", C.c_double, ptr)
+dy = function("ei_event_pointer_get_dy", C.c_double, ptr)
+key = function("ei_event_keyboard_get_key", C.c_uint32, ptr)
+pressed = function("ei_event_keyboard_get_key_is_press", C.c_bool, ptr)
+stop_x = function("ei_event_scroll_get_stop_x", C.c_bool, ptr)
+stop_y = function("ei_event_scroll_get_stop_y", C.c_bool, ptr)
+fd = function("ei_get_fd", C.c_int, ptr)
+context = new(None)
+assert context and setup(context, os.dup(0)) == 0
+seen = {"motion": [], "keys": [], "stops": [], "starts": 0, "ends": 0, "keymap": False}
+deadline = time.monotonic() + 10
+try:
+    while time.monotonic() < deadline:
+        select.select([fd(context)], [], [], 0.05)
+        dispatch(context)
+        while event := next_event(context):
+            event_type = kind(event)
+            if event_type == 2:
+                raise AssertionError("EIS disconnected before completing capture")
+            if event_type == 3:
+                bind(seat(event), C.c_int(1), C.c_int(4), C.c_int(16), C.c_int(32), C.c_void_p())
+            elif event_type == 5:
+                if mapping := keymap(device(event)):
+                    content = os.pread(map_fd(mapping), map_size(mapping), 0)
+                    assert content.endswith(b"\0") and b"xkb_keymap" in content
+                    seen["keymap"] = True
+            elif event_type == 200:
+                seen["starts"] += 1
+            elif event_type == 201:
+                seen["ends"] += 1
+            elif event_type == 300:
+                seen["motion"].append([dx(event), dy(event)])
+            elif event_type == 700:
+                seen["keys"].append([key(event), pressed(event)])
+            elif event_type == 601:
+                seen["stops"].append([stop_x(event), stop_y(event)])
+            unref_event(event)
+        if seen["ends"] == 2:
+            assert seen == {"motion": [[10.0, -5.0], [10.0, -5.0]], "keys": [[30, True], [30, False]], "stops": [[False, True]], "starts": 2, "ends": 2, "keymap": True}, seen
+            print(json.dumps(seen), flush=True)
+            break
+    else:
+        raise AssertionError(f"Timed out: {seen}")
+finally:
+    unref(context)

scripts/tests/test_portal_contracts.py

@@ -54,7 +54,7 @@ def private_bus_checks():
                         raise AssertionError((root / "backend.log").read_text())
                     time.sleep(0.05)
             node = ET.fromstring(xml)
-            for name in ("ScreenCast", "Settings", "Screenshot", "Wallpaper", "Background", "Usb", "Lockdown", "GlobalShortcuts", "Inhibit"):
+            for name in ("ScreenCast", "Settings", "Screenshot", "Wallpaper", "Background", "Usb", "Lockdown", "GlobalShortcuts", "Inhibit", "InputCapture"):
                 interface = node.find(f"interface[@name='org.freedesktop.impl.portal.{name}']")
                 assert interface is not None, name
                 expected = ET.parse(f"/usr/share/dbus-1/interfaces/org.freedesktop.impl.portal.{name}.xml").getroot().find("interface")
@@ -110,6 +110,18 @@ def private_bus_checks():
                                          GLib.Variant("(su)", ("org.freedesktop.portal.Desktop", 0)), GLib.VariantType.new("(u)"),
                                          Gio.DBusCallFlags.NONE, 5000, None).unpack()[0]
             assert request_name == 1
+            capture = "org.freedesktop.impl.portal.InputCapture"
+            caps, = call("org.freedesktop.DBus.Properties", "Get", GLib.Variant("(ss)", (capture, "SupportedCapabilities")), "(v)")
+            assert caps == 3
+            session = PATH + "/session/test/inputcapture"
+            call(capture, "CreateSession2", GLib.Variant("(osa{sv})", (session, "org.test.Capture", {})), "(a{sv})")
+            try:
+                call(capture, "GetZones", GLib.Variant("(oosa{sv})", (PATH + "/request/test/zones", session, "org.test.Capture", {})))
+                raise AssertionError("Zones available without approval")
+            except GLib.Error as error:
+                assert "InvalidArgs" in str(error), error
+            bus.call_sync(NAME, session, "org.freedesktop.impl.portal.Session", "Close", None, None, Gio.DBusCallFlags.NONE, 5000, None)
+
             version, = call("org.freedesktop.DBus.Properties", "Get", GLib.Variant("(ss)", ("org.freedesktop.impl.portal.ScreenCast", "version")), "(v)")
             assert version == 4
             source_types, = call("org.freedesktop.DBus.Properties", "Get", GLib.Variant("(ss)", ("org.freedesktop.impl.portal.ScreenCast", "AvailableSourceTypes")), "(v)")