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Commit 26640c99 authored by Harry Cutts's avatar Harry Cutts
Browse files

InputVerifier: verify button events and states (attempt 2) 

Check the following things:

* BUTTON_PRESS and _RELEASE actions have a single, valid action button
* No redundant BUTTON_PRESS or _RELEASE actions (i.e. for buttons that
  are already pressed or released)
* Button state remains consistent throughout the stream, i.e.:
  * Buttons are only added to the state by BUTTON_PRESS (though DOWN
    events can have "pending" buttons on them)
  * Buttons are only removed from the state by BUTTON_RELEASE
  * When a DOWN event has pending buttons in its state, it is
    immediately followed by a BUTTON_PRESS for each one

We could also verify that press and release events for primary,
secondary, and tertiary buttons are accompanied by down and up events.
However, I couldn't find any documentation that states which buttons
should result in down or up events, so I haven't implemented this for
now.

This is the second attempt to land this change, due to the original
causing test failures. Change I5c259c13d433d3010d2cf9c6fe01e08ba5990ef7
fixes the failures. v2 also adds a separate flag for button state
verification, as it is actually used in production to check events
injected by assistive technologies, whether or not the flag that I
previously thought was guarding it is enabled.

Test: connect a mouse and a touchpad, enable the verifier, play around
      with the buttons, and check that any issues found by the verifier
      appear to be legitimate. (I found b/391298464 , and checked that
      the verifier caught a button problem with a partial fix to
      b/372571823 .)
Test: atest --host libinput_rust_tests
Test: atest --host frameworks/native/libs/input/tests/InputVerifier_test.cpp
Test: atest --host \
      frameworks/native/services/inputflinger/tests/InputDispatcher_test.cpp
Bug: 392870542
Flag: com.android.input.flags.enable_button_state_verification
Change-Id: I46f489b26df8785563e41e58135b6b5de4ff62a2
parent 03ec059e

include/android/input.h

+2 −0
Original line number Diff line number Diff line
@@ -849,6 +849,7 @@ enum { 
 * Refer to the documentation on the MotionEvent class for descriptions of each button.

 */

enum {

    // LINT.IfChange(AMOTION_EVENT_BUTTON)

    /** primary */

    AMOTION_EVENT_BUTTON_PRIMARY = 1 << 0,

    /** secondary */
@@ -861,6 +862,7 @@ enum { 
    AMOTION_EVENT_BUTTON_FORWARD = 1 << 4,

    AMOTION_EVENT_BUTTON_STYLUS_PRIMARY = 1 << 5,

    AMOTION_EVENT_BUTTON_STYLUS_SECONDARY = 1 << 6,

    // LINT.ThenChange(/frameworks/native/libs/input/rust/input.rs)

};



/**

include/input/InputVerifier.h

+3 −2
Original line number Diff line number Diff line
@@ -47,9 +47,10 @@ public: 
    InputVerifier(const std::string& name);



    android::base::Result<void> processMovement(int32_t deviceId, int32_t source, int32_t action,

                                                uint32_t pointerCount,

                                                int32_t actionButton, uint32_t pointerCount,

                                                const PointerProperties* pointerProperties,

                                                const PointerCoords* pointerCoords, int32_t flags);

                                                const PointerCoords* pointerCoords, int32_t flags,

                                                int32_t buttonState);



    void resetDevice(int32_t deviceId);

libs/input/Android.bp

+7 −0
Original line number Diff line number Diff line
@@ -133,6 +133,13 @@ rust_bindgen { 
        "--allowlist-var=AMOTION_EVENT_ACTION_POINTER_DOWN",

        "--allowlist-var=AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT",

        "--allowlist-var=AMOTION_EVENT_ACTION_UP",

        "--allowlist-var=AMOTION_EVENT_BUTTON_BACK",

        "--allowlist-var=AMOTION_EVENT_BUTTON_FORWARD",

        "--allowlist-var=AMOTION_EVENT_BUTTON_PRIMARY",

        "--allowlist-var=AMOTION_EVENT_BUTTON_SECONDARY",

        "--allowlist-var=AMOTION_EVENT_BUTTON_STYLUS_PRIMARY",

        "--allowlist-var=AMOTION_EVENT_BUTTON_STYLUS_SECONDARY",

        "--allowlist-var=AMOTION_EVENT_BUTTON_TERTIARY",

        "--allowlist-var=MAX_POINTER_ID",

        "--verbose",

    ],

libs/input/InputTransport.cpp

+3 −3
Original line number Diff line number Diff line
@@ -651,9 +651,9 @@ status_t InputPublisher::publishMotionEvent( 
    const status_t status = mChannel->sendMessage(&msg);



    if (status == OK && verifyEvents()) {

        Result<void> result =

                mInputVerifier.processMovement(deviceId, source, action, pointerCount,

                                               pointerProperties, pointerCoords, flags);

        Result<void> result = mInputVerifier.processMovement(deviceId, source, action, actionButton,

                                                             pointerCount, pointerProperties,

                                                             pointerCoords, flags, buttonState);

        if (!result.ok()) {

            LOG(ERROR) << "Bad stream: " << result.error();

            return BAD_VALUE;

libs/input/InputVerifier.cpp

+13 −4
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#define LOG_TAG "InputVerifier"



#include <android-base/logging.h>

#include <com_android_input_flags.h>

#include <input/InputVerifier.h>

#include "input_cxx_bridge.rs.h"
@@ -26,17 +27,23 @@ using android::input::RustPointerProperties; 


using DeviceId = int32_t;



namespace input_flags = com::android::input::flags;



namespace android {



// --- InputVerifier ---



InputVerifier::InputVerifier(const std::string& name)

      : mVerifier(android::input::verifier::create(rust::String::lossy(name))){};

      : mVerifier(

                android::input::verifier::create(rust::String::lossy(name),

                                                 input_flags::enable_button_state_verification())) {

}



Result<void> InputVerifier::processMovement(DeviceId deviceId, int32_t source, int32_t action,

                                            uint32_t pointerCount,

                                            int32_t actionButton, uint32_t pointerCount,

                                            const PointerProperties* pointerProperties,

                                            const PointerCoords* pointerCoords, int32_t flags) {

                                            const PointerCoords* pointerCoords, int32_t flags,

                                            int32_t buttonState) {

    std::vector<RustPointerProperties> rpp;

    for (size_t i = 0; i < pointerCount; i++) {

        rpp.emplace_back(RustPointerProperties{.id = pointerProperties[i].id});
@@ -44,7 +51,9 @@ Result<void> InputVerifier::processMovement(DeviceId deviceId, int32_t source, i 
    rust::Slice<const RustPointerProperties> properties{rpp.data(), rpp.size()};

    rust::String errorMessage =

            android::input::verifier::process_movement(*mVerifier, deviceId, source, action,

                                                       properties, static_cast<uint32_t>(flags));

                                                       actionButton, properties,

                                                       static_cast<uint32_t>(flags),

                                                       static_cast<uint32_t>(buttonState));

    if (errorMessage.empty()) {

        return {};

    } else {