cloudfox-coreshift-core 2.5.1

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/

//! DisplayManager binder client.
//!
//! Display-state callbacks (`IDisplayManagerCallback`), Android 14
//! `DisplayInfo` parcel decoding for FPS normalization, and the
//! power-service `isInteractive` probe.

use super::sys::*;
use crate::CoreError;
use std::os::fd::{AsRawFd, FromRawFd, IntoRawFd, OwnedFd};
use std::os::raw::{c_char, c_void};
use std::sync::Mutex;

/// Decoded subset of the Android 14 `android.view.DisplayInfo` parcel used
/// for FPS normalization.
struct ParsedDisplayInfo {
    active_mode_id: i32,
    vsync_rate: f32,
    peak_refresh_rate: f32,
    render_frame_rate: f32,
}

/// Walk the `IDisplayManager.getDisplayInfo` reply parcel following the
/// Android 14 `android.view.DisplayInfo.writeToParcel` field order.
///
/// Field order (Android 14):
/// layerStack, flags, type, displayId, displayGroupId (5×i32), then a
/// nullable `DisplayAddress` parcelable (`writeParcelable` → a String16
/// class name, or a single `-1` marker for null), a nullable
/// `DeviceProductInfo` parcelable, then `name` as a **String8** (Java
/// `writeString8`), 8 logical-dimension i32s, the `DisplayCutout`
/// ParcelableWrapper, rotation/modeId/renderFrameRate/defaultModeId, and
/// `supportedModes`. Only fields up to `supportedModes` are consumed — the
/// tail (color modes, HDR, rounded corners, …) is never touched.
///
/// `AParcel_readString` decodes String16 only; `name` is String8, so it is
/// consumed with `skip_string8`. Null strings and null parcelables carry a
/// `-1` length marker, which `string_alloc` now accepts so they decode to
/// `None` rather than a hard `STATUS_UNEXPECTED_NULL`.
///
/// Validity gate: any value shape outside the expected one returns a
/// `CoreError` tagged `display_info` so on-device logs identify the layout
/// mismatch.
fn parse_display_info(r: &ParcelReader<'_>) -> Result<ParsedDisplayInfo, CoreError> {
    // 1. layerStack/type/displayId prefix: layerStack, flags, type,
    //    displayId, displayGroupId.
    r.skip_i32s(5)?;

    // 2. address: nullable DisplayAddress parcelable. Non-null writes the
    //    class name as a String16 then the body; null writes a -1 marker.
    //    Body differs by subtype: Physical → 1×i64 display id, Network →
    //    String16 mac address. Dispatch on the decoded class name so a
    //    network display cannot desync the walk.
    if let Some(addr_class) = r.read_string()? {
        if addr_class.ends_with("$Physical") {
            r.read_int64()?;
        } else if addr_class.ends_with("$Network") {
            r.skip_string16()?;
        } else {
            return Err(CoreError::binder(
                -1,
                "display_info:unsupported DisplayAddress",
            ));
        }
    }

    // 3. deviceProductInfo: nullable parcelable (same null probe). Body:
    //    mName (String16), mManufacturerPnpId (String16), then three
    //    readValue() fields — mProductId (String), mModelYear (Integer),
    //    mManufactureDate (nullable ManufactureDate parcelable) — and a
    //    final mConnectionToSinkType i32. The ManufactureDate parcelable is
    //    length-prefixed, so skip_value's VAL_PARCELABLE case consumes it
    //    wholesale including its internal writeValue fields.
    if let Some(_dpi_class) = r.read_string()? {
        r.skip_string16()?; // mName
        r.skip_string16()?; // mManufacturerPnpId
        r.skip_value()?; // mProductId
        r.skip_value()?; // mModelYear
        r.skip_value()?; // mManufactureDate
        r.read_i32()?; // mConnectionToSinkType
    }

    // 4. name — Java `writeString8`, a String8 (byte length + UTF-8), may
    //    be null. Must NOT be read with read_string() (String16 only).
    r.skip_string8()?;

    // 5. Logical dimensions: appWidth, appHeight, smallestNominalAppWidth,
    //    smallestNominalAppHeight, largestNominalAppWidth,
    //    largestNominalAppHeight, logicalWidth, logicalHeight (8×i32).
    r.skip_i32s(8)?;

    // 6. displayCutout: ParcelableWrapper. writeCutoutToParcel writes -1
    //    (null), 0 (NO_CUTOUT), or 1 + body. Body: safeInsets (typed
    //    Rect), bounds (typed Rect array), waterfallInsets (typed Rect),
    //    4×i32 cutout path parser dims, density f32, cutoutSpec String16,
    //    rotation i32, scale f32, physicalPixelDisplaySizeRatio f32.
    let cutout_marker = r.read_i32()?;
    if cutout_marker == 1 {
        r.skip_typed_rect()?; // mSafeInsets
        let bounds = r.read_i32()?; // mBounds Rect[]
        if bounds >= 0 {
            for _ in 0..bounds {
                r.skip_typed_rect()?;
            }
        }
        r.skip_typed_rect()?; // mWaterfallInsets
        r.skip_i32s(4)?; // cutout path parser info (display/phys dims)
        r.read_float()?; // density
        r.skip_string16()?; // cutoutSpec
        r.read_i32()?; // rotation
        r.read_float()?; // scale
        r.read_float()?; // physicalPixelDisplaySizeRatio
    }

    // 7. rotation (i32), modeId (i32), renderFrameRate (f32),
    //    defaultModeId (i32), then nModes (i32).
    r.read_i32()?; // rotation
    let active_mode_id = r.read_i32()?;
    let render_frame_rate = {
        let v = r.read_float()?;
        if v.is_finite() && v >= 0.0 { v } else { 0.0 }
    };
    r.read_i32()?; // defaultModeId
    let n_modes = r.read_i32()?.max(0) as usize;

    // 8. supportedModes: each Display.Mode = { modeId, width, height,
    //    refreshRate (×4 primitive) + alternativeRefreshRates float[],
    //    supportedHdrTypes int[] }.
    let mut vsync_rate: f32 = 0.0;
    let mut peak_refresh_rate: f32 = 0.0;
    for _ in 0..n_modes {
        let mode_id = r.read_i32()?;
        r.read_i32()?; // width
        r.read_i32()?; // height
        let refresh_rate = {
            let v = r.read_float()?;
            // collapse NaN/±Inf/negative like the FPS path; otherwise a
            // hostile peer could leak +Inf into the public DisplayInfo.
            if v.is_finite() && v >= 0.0 { v } else { 0.0 }
        };
        // alternativeRefreshRates: float[] (count + values)
        let alt = r.read_i32()?.max(0) as usize;
        for _ in 0..alt {
            let _f = r.read_float()?;
        }
        // supportedHdrTypes: int[]
        let hdr = r.read_i32()?.max(0) as usize;
        for _ in 0..hdr {
            r.read_i32()?;
        }
        peak_refresh_rate = peak_refresh_rate.max(refresh_rate);
        if mode_id == active_mode_id {
            vsync_rate = refresh_rate.max(vsync_rate);
        }
    }

    Ok(ParsedDisplayInfo {
        active_mode_id,
        vsync_rate,
        peak_refresh_rate,
        render_frame_rate,
    })
}
// ── DisplayManager ─────────────────────────────────────────────────

const DISPLAY_SERVICE: &[u8] = b"display\0";
const DISPLAY_DESCRIPTOR: &[u8] = b"android.hardware.display.IDisplayManager\0";
const CALLBACK_DESCRIPTOR: &[u8] = b"android.hardware.display.IDisplayManagerCallback\0";
const POWER_SERVICE: &[u8] = b"power\0";
const POWER_DESCRIPTOR: &[u8] = b"android.os.IPowerManager\0";

const TX_DISPLAY_REGISTER_CALLBACK: u32 = 4;

// Core owns the callback eventfd; the consumer gets a dup and may close it
// freely. Same lifetime discipline as the ActivityManager observer (C2).
static DISP_EVENTFD: Mutex<Option<OwnedFd>> = Mutex::new(None);

fn disp_eventfd_guard() -> std::sync::MutexGuard<'static, Option<OwnedFd>> {
    DISP_EVENTFD.lock().unwrap_or_else(|p| p.into_inner())
}

unsafe extern "C" fn disp_cb_on_create(_: *mut c_void) -> *mut c_void {
    std::ptr::null_mut()
}
unsafe extern "C" fn disp_cb_on_destroy(_: *mut c_void) {}
unsafe extern "C" fn disp_cb_on_transact(
    _: *mut AIBinder,
    code: u32,
    _: *const AParcel,
    _: *mut AParcel,
) -> BinderStatus {
    if code == 1 {
        if let Some(fd) = disp_eventfd_guard().as_ref() {
            let val: u64 = 1;
            unsafe { libc::write(fd.as_raw_fd(), &val as *const u64 as *const c_void, 8) };
        }
    }
    STATUS_OK
}
// Client-only classes: the NDK requires a class on ANY binder that
// participates in a transaction (AIBinder_prepareTransaction fails with
// STATUS_INVALID_OPERATION when getClass() == null) and uses the class
// descriptor to write the interface token. These stubs are never invoked
// for a client (remote) binder — onCreate/onTransact only fire on local
// AIBinder_new instances — so they mirror the ActivityManager client
// pattern exactly.
unsafe extern "C" fn disp_client_on_create(_: *mut c_void) -> *mut c_void {
    std::ptr::null_mut()
}
unsafe extern "C" fn disp_client_on_destroy(_: *mut c_void) {}
unsafe extern "C" fn disp_client_on_transact(
    _: *mut AIBinder,
    _: u32,
    _: *const AParcel,
    _: *mut AParcel,
) -> BinderStatus {
    STATUS_UNKNOWN_TRANSACTION
}
/// Snapshot of the active display state used for FPS normalization.
///
/// Populated from `IDisplayManager.getDisplayInfo` (tx resolved from the
/// installed ROM's framework.jar). The parcel layout is Android-version
/// specific; this parse targets Android 14 and must be validated on-device
/// before consumers rely on the values for fps/R normalization.
#[derive(Clone, Copy, Debug, PartialEq, Default)]
pub struct DisplayInfo {
    /// Active display mode id (`DisplayInfo.modeId`).
    pub active_mode_id: i32,
    /// Refresh rate of the active mode, in Hz.
    pub vsync_rate: f32,
    /// Highest refresh rate across supported modes, in Hz.
    pub peak_refresh_rate: f32,
    /// `DisplayInfo.renderFrameRate` (Android 13+), in Hz.
    pub render_frame_rate: f32,
    /// Interactive state reported by the power service.
    pub is_interactive: bool,
}

pub struct DisplayManager {
    _lib: DlHandle,
    vt: Vtable,
    display: Option<OwnedBinder>,
    display_info_tx: Option<u32>,
    power: Option<OwnedBinder>,
    is_interactive_tx: u32,
}
unsafe impl Send for DisplayManager {}

impl DisplayManager {
    pub fn open_with_callback() -> Result<(Self, crate::fd::Fd), CoreError> {
        let handle = unsafe {
            libc::dlopen(
                LIBBINDER_PATH.as_ptr() as *const c_char,
                libc::RTLD_NOW | libc::RTLD_LOCAL,
            )
        };
        if handle.is_null() {
            return Err(CoreError::binder(-1, "dlopen:libbinder_ndk.so"));
        }
        let lib = DlHandle;
        let vt = load_vtable(handle)?;

        // Blocking eventfd (no EFD_NONBLOCK) — callback writes, caller's
        // read_u64_blocking() waits. The core owns it for the callback's
        // lifetime; the consumer receives a dup below (C2).
        let owned = unsafe {
            let raw = libc::eventfd(0, libc::EFD_CLOEXEC);
            if raw < 0 {
                return Err(CoreError::sys(*libc::__errno(), "eventfd"));
            }
            OwnedFd::from_raw_fd(raw)
        };

        // Get display service. A client-only binder still needs a class
        // (AIBinder_prepareTransaction requires getClass() != null and
        // writes the interface token from the class descriptor).
        let raw_display = unsafe { (vt.get_service)(DISPLAY_SERVICE.as_ptr() as *const c_char) };
        if raw_display.is_null() {
            return Err(CoreError::binder(-1, "AServiceManager_getService:display"));
        }
        let display_class = unsafe {
            (vt.class_define)(
                DISPLAY_DESCRIPTOR.as_ptr() as *const c_char,
                disp_client_on_create,
                disp_client_on_destroy,
                disp_client_on_transact,
            )
        };
        if display_class.is_null() {
            return Err(CoreError::binder(
                -1,
                "AIBinder_Class_define:IDisplayManager",
            ));
        }
        unsafe { (vt.associate_class)(raw_display, display_class) };
        let display = OwnedBinder {
            ptr: raw_display,
            dec_strong: vt.dec_strong,
        };

        // Define IDisplayManagerCallback (we're the server receiving callbacks)
        let cb_class = unsafe {
            (vt.class_define)(
                CALLBACK_DESCRIPTOR.as_ptr() as *const c_char,
                disp_cb_on_create,
                disp_cb_on_destroy,
                disp_cb_on_transact,
            )
        };
        if cb_class.is_null() {
            return Err(CoreError::binder(
                -1,
                "AIBinder_Class_define:DisplayCallback",
            ));
        }

        let cb_binder = unsafe { (vt.new_binder)(cb_class, std::ptr::null_mut()) };
        if cb_binder.is_null() {
            return Err(CoreError::binder(-1, "AIBinder_new:DisplayCallback"));
        }

        // registerCallback(callback) — tx 4
        let _ = transact_write(&vt, display.ptr, TX_DISPLAY_REGISTER_CALLBACK, |w| {
            w.write_strong_binder(cb_binder)
        })?;

        // Optional: grab power service for is_interactive(). Same client
        // class requirement as the display binder above.
        let power_class = unsafe {
            (vt.class_define)(
                POWER_DESCRIPTOR.as_ptr() as *const c_char,
                disp_client_on_create,
                disp_client_on_destroy,
                disp_client_on_transact,
            )
        };
        let power = if power_class.is_null() {
            None
        } else {
            let raw = unsafe { (vt.get_service)(POWER_SERVICE.as_ptr() as *const c_char) };
            if raw.is_null() {
                None
            } else {
                unsafe { (vt.associate_class)(raw, power_class) };
                Some(OwnedBinder {
                    ptr: raw,
                    dec_strong: vt.dec_strong,
                })
            }
        };

        // Resolve isInteractive tx code from DEX at open time
        let is_interactive_tx = crate::android::dex::resolve_is_interactive_tx()
            .ok_or_else(|| CoreError::binder(-1, "dex:TRANSACTION_isInteractive not found"))?;

        // Resolve getDisplayInfo tx from DEX (best-effort, optional). ROMs
        // that drop the field skip the info() API rather than failing open.
        let display_info_tx = crate::android::dex::resolve_display_info_tx();

        // Consumer dup — made before publishing, so an error path drops the
        // owned fd without ever leaving a stale handle for the callback.
        let efd_owned = owned
            .try_clone()
            .map_err(|e| CoreError::sys(e.raw_os_error().unwrap_or(-1), "dup:display"))
            .and_then(|dup| unsafe {
                crate::fd::Fd::from_owned_raw_fd(dup.into_raw_fd(), "display.efd")
                    .map_err(|_| CoreError::binder(-1, "Fd::from_owned_raw_fd:display.efd"))
            })?;

        // Publish the core-owned eventfd for the callback
        *disp_eventfd_guard() = Some(owned);

        // Join binder thread pool so callbacks can fire
        unsafe { (vt.set_thread_pool_max)(0) };
        let join_fn = vt.join_thread_pool;
        std::thread::spawn(move || unsafe { join_fn() });

        Ok((
            Self {
                _lib: lib,
                vt,
                display: Some(display),
                display_info_tx,
                power,
                is_interactive_tx,
            },
            efd_owned,
        ))
    }

    pub fn is_interactive(&self) -> Result<bool, CoreError> {
        let power = self
            .power
            .as_ref()
            .ok_or_else(|| CoreError::binder(-1, "power:unavailable"))?;
        let out = transact_write(&self.vt, power.ptr, self.is_interactive_tx, |_| Ok(()))?;
        let r = ParcelReader {
            vt: &self.vt,
            parcel: &out,
        };
        let ex = r.read_i32()?;
        if ex != EX_NONE {
            return Err(CoreError::binder(ex, "isInteractive:exception"));
        }
        r.read_bool()
    }

    /// Query the display's current render state for FPS normalization.
    ///
    /// Transacts `IDisplayManager.getDisplayInfo(display_id)` and decodes
    /// the reply parcel (Android 14 `android.view.DisplayInfo` layout):
    /// active mode id, active-mode refresh rate, peak refresh rate across
    /// supported modes, and `renderFrameRate`, plus the interactive state
    /// from the power service.
    ///
    /// # Best-effort / on-device caveat
    /// The parcel walk below follows the Android 14 field ordering. ROMs or
    /// future Android releases that reorder `DisplayInfo` fields will fail
    /// the walk with a `CoreError` (never garbage) — tune
    /// `parse_display_info` against the installed framework.jar, which is
    /// why the tx code is resolved at open time via DEX.
    pub fn info(&self, display_id: i32) -> Result<DisplayInfo, CoreError> {
        let display = self
            .display
            .as_ref()
            .ok_or_else(|| CoreError::binder(-1, "display:unavailable"))?;
        let tx = self
            .display_info_tx
            .ok_or_else(|| CoreError::binder(-1, "display_info:tx unavailable"))?;
        let out = transact_write(&self.vt, display.ptr, tx, |w| w.write_i32(display_id))?;
        let r = ParcelReader {
            vt: &self.vt,
            parcel: &out,
        };

        let ex = r.read_i32()?;
        if ex != EX_NONE {
            return Err(CoreError::binder(ex, "getDisplayInfo:exception"));
        }
        // The reply parcel carries the parcelable off the framework's own
        // writeToParcel, which writes no class-name header for a top-level
        // reply value in native code — it is the raw DisplayInfo fields.
        // The first field read must be layerStack. If a future framework
        // writes a class name first, the first read becomes a string length
        // (small positive int) and `layer_stack` is a plausible-looking
        // wrong value; guard by sanity-checking later fields instead.
        let parsed = parse_display_info(&r)?;

        let interactive = self.is_interactive().unwrap_or(false);
        Ok(DisplayInfo {
            active_mode_id: parsed.active_mode_id,
            vsync_rate: parsed.vsync_rate,
            peak_refresh_rate: parsed.peak_refresh_rate,
            render_frame_rate: parsed.render_frame_rate,
            is_interactive: interactive,
        })
    }
}