Support native API to report sysfs nodes changes

When a sysfs node change is reported, check if any new
perpherals are added and if added, recreate input device.

Test: atest inputfliger_tests
Bug: 265057712
Change-Id: Ic6c0c00de9ae963f0651859bdbc57e45af7ccd07
diff --git a/services/inputflinger/include/InputReaderBase.h b/services/inputflinger/include/InputReaderBase.h
index 841c914..1750c64 100644
--- a/services/inputflinger/include/InputReaderBase.h
+++ b/services/inputflinger/include/InputReaderBase.h
@@ -149,6 +149,9 @@
 
     /* Get the Bluetooth address of an input device, if known. */
     virtual std::optional<std::string> getBluetoothAddress(int32_t deviceId) const = 0;
+
+    /* Sysfs node change reported. Recreate device if required to incorporate the new sysfs nodes */
+    virtual void sysfsNodeChanged(const std::string& sysfsNodePath) = 0;
 };
 
 // --- InputReaderConfiguration ---
diff --git a/services/inputflinger/reader/EventHub.cpp b/services/inputflinger/reader/EventHub.cpp
index e65f3af..ee8dde1 100644
--- a/services/inputflinger/reader/EventHub.cpp
+++ b/services/inputflinger/reader/EventHub.cpp
@@ -1531,6 +1531,20 @@
     return associatedDevice;
 }
 
+bool EventHub::AssociatedDevice::isChanged() const {
+    std::unordered_map<int32_t, RawBatteryInfo> newBatteryInfos =
+            readBatteryConfiguration(sysfsRootPath);
+    std::unordered_map<int32_t, RawLightInfo> newLightInfos =
+            readLightsConfiguration(sysfsRootPath);
+    std::optional<RawLayoutInfo> newLayoutInfo = readLayoutConfiguration(sysfsRootPath);
+
+    if (newBatteryInfos == batteryInfos && newLightInfos == lightInfos &&
+        newLayoutInfo == layoutInfo) {
+        return false;
+    }
+    return true;
+}
+
 void EventHub::vibrate(int32_t deviceId, const VibrationElement& element) {
     std::scoped_lock _l(mLock);
     Device* device = getDeviceLocked(deviceId);
@@ -2536,6 +2550,42 @@
     return device->disable();
 }
 
+// TODO(b/274755573): Shift to uevent handling on native side and remove this method
+// Currently using Java UEventObserver to trigger this which uses UEvent infrastructure that uses a
+// NETLINK socket to observe UEvents. We can create similar infrastructure on Eventhub side to
+// directly observe UEvents instead of triggering from Java side.
+void EventHub::sysfsNodeChanged(const std::string& sysfsNodePath) {
+    std::scoped_lock _l(mLock);
+
+    // Check in opening devices
+    for (auto it = mOpeningDevices.begin(); it != mOpeningDevices.end(); it++) {
+        std::unique_ptr<Device>& device = *it;
+        if (device->associatedDevice &&
+            sysfsNodePath.find(device->associatedDevice->sysfsRootPath.string()) !=
+                    std::string::npos &&
+            device->associatedDevice->isChanged()) {
+            it = mOpeningDevices.erase(it);
+            openDeviceLocked(device->path);
+        }
+    }
+
+    // Check in already added device
+    std::vector<Device*> devicesToReopen;
+    for (const auto& [id, device] : mDevices) {
+        if (device->associatedDevice &&
+            sysfsNodePath.find(device->associatedDevice->sysfsRootPath.string()) !=
+                    std::string::npos &&
+            device->associatedDevice->isChanged()) {
+            devicesToReopen.push_back(device.get());
+        }
+    }
+    for (const auto& device : devicesToReopen) {
+        closeDeviceLocked(*device);
+        openDeviceLocked(device->path);
+    }
+    devicesToReopen.clear();
+}
+
 void EventHub::createVirtualKeyboardLocked() {
     InputDeviceIdentifier identifier;
     identifier.name = "Virtual";
diff --git a/services/inputflinger/reader/InputReader.cpp b/services/inputflinger/reader/InputReader.cpp
index 9080cc1..81ac03b 100644
--- a/services/inputflinger/reader/InputReader.cpp
+++ b/services/inputflinger/reader/InputReader.cpp
@@ -928,6 +928,10 @@
     return *associatedDisplayId == displayId;
 }
 
+void InputReader::sysfsNodeChanged(const std::string& sysfsNodePath) {
+    mEventHub->sysfsNodeChanged(sysfsNodePath);
+}
+
 void InputReader::dump(std::string& dump) {
     std::scoped_lock _l(mLock);
 
diff --git a/services/inputflinger/reader/include/EventHub.h b/services/inputflinger/reader/include/EventHub.h
index 0b15efe..20612c7 100644
--- a/services/inputflinger/reader/include/EventHub.h
+++ b/services/inputflinger/reader/include/EventHub.h
@@ -388,6 +388,10 @@
 
     /* Disable an input device. Closes file descriptor to that device. */
     virtual status_t disableDevice(int32_t deviceId) = 0;
+
+    /* Sysfs node changed. Reopen the Eventhub device if any new Peripheral like Light, Battery,
+     * etc. is detected. */
+    virtual void sysfsNodeChanged(const std::string& sysfsNodePath) = 0;
 };
 
 template <std::size_t BITS>
@@ -567,6 +571,8 @@
 
     status_t disableDevice(int32_t deviceId) override final;
 
+    void sysfsNodeChanged(const std::string& sysfsNodePath) override final;
+
     ~EventHub() override;
 
 private:
@@ -578,6 +584,7 @@
         std::unordered_map<int32_t /*lightId*/, RawLightInfo> lightInfos;
         std::optional<RawLayoutInfo> layoutInfo;
 
+        bool isChanged() const;
         bool operator==(const AssociatedDevice&) const = default;
         bool operator!=(const AssociatedDevice&) const = default;
         std::string dump() const;
diff --git a/services/inputflinger/reader/include/InputReader.h b/services/inputflinger/reader/include/InputReader.h
index e9c989a..120e150 100644
--- a/services/inputflinger/reader/include/InputReader.h
+++ b/services/inputflinger/reader/include/InputReader.h
@@ -117,6 +117,8 @@
 
     std::optional<std::string> getBluetoothAddress(int32_t deviceId) const override;
 
+    void sysfsNodeChanged(const std::string& sysfsNodePath) override;
+
 protected:
     // These members are protected so they can be instrumented by test cases.
     virtual std::shared_ptr<InputDevice> createDeviceLocked(int32_t deviceId,
diff --git a/services/inputflinger/tests/FakeEventHub.cpp b/services/inputflinger/tests/FakeEventHub.cpp
index ff6d584..4626f5a 100644
--- a/services/inputflinger/tests/FakeEventHub.cpp
+++ b/services/inputflinger/tests/FakeEventHub.cpp
@@ -594,4 +594,33 @@
     return lightIt->second;
 };
 
+void FakeEventHub::setSysfsRootPath(int32_t deviceId, std::string sysfsRootPath) const {
+    Device* device = getDevice(deviceId);
+    if (device == nullptr) {
+        return;
+    }
+    device->sysfsRootPath = sysfsRootPath;
+}
+
+void FakeEventHub::sysfsNodeChanged(const std::string& sysfsNodePath) {
+    int32_t foundDeviceId = -1;
+    Device* foundDevice = nullptr;
+    for (size_t i = 0; i < mDevices.size(); i++) {
+        Device* d = mDevices.valueAt(i);
+        if (sysfsNodePath.find(d->sysfsRootPath) != std::string::npos) {
+            foundDeviceId = mDevices.keyAt(i);
+            foundDevice = d;
+        }
+    }
+    if (foundDevice == nullptr) {
+        return;
+    }
+    // If device sysfs changed -> reopen the device
+    if (!mRawLightInfos.empty() && !foundDevice->classes.test(InputDeviceClass::LIGHT)) {
+        removeDevice(foundDeviceId);
+        addDevice(foundDeviceId, foundDevice->identifier.name,
+                  foundDevice->classes | InputDeviceClass::LIGHT, foundDevice->identifier.bus);
+    }
+}
+
 } // namespace android
diff --git a/services/inputflinger/tests/FakeEventHub.h b/services/inputflinger/tests/FakeEventHub.h
index e0a3f9e..8e06940 100644
--- a/services/inputflinger/tests/FakeEventHub.h
+++ b/services/inputflinger/tests/FakeEventHub.h
@@ -64,6 +64,7 @@
         std::vector<VirtualKeyDefinition> virtualKeys;
         bool enabled;
         std::optional<RawLayoutInfo> layoutInfo;
+        std::string sysfsRootPath;
 
         status_t enable() {
             enabled = true;
@@ -152,6 +153,7 @@
     void enqueueEvent(nsecs_t when, nsecs_t readTime, int32_t deviceId, int32_t type, int32_t code,
                       int32_t value);
     void assertQueueIsEmpty();
+    void setSysfsRootPath(int32_t deviceId, std::string sysfsRootPath) const;
 
 private:
     Device* getDevice(int32_t deviceId) const;
@@ -212,7 +214,7 @@
     std::optional<int32_t> getLightBrightness(int32_t deviceId, int32_t lightId) const override;
     std::optional<std::unordered_map<LightColor, int32_t>> getLightIntensities(
             int32_t deviceId, int32_t lightId) const override;
-
+    void sysfsNodeChanged(const std::string& sysfsNodePath) override;
     void dump(std::string&) const override {}
     void monitor() const override {}
     void requestReopenDevices() override {}
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index 853c5b0..48ffc15 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -644,6 +644,30 @@
     ASSERT_EQ(0U, inputDevices[0].getMotionRanges().size());
 }
 
+TEST_F(InputReaderTest, InputDeviceRecreatedOnSysfsNodeChanged) {
+    ASSERT_NO_FATAL_FAILURE(addDevice(1, "keyboard", InputDeviceClass::KEYBOARD, nullptr));
+    mFakeEventHub->setSysfsRootPath(1, "xyz");
+
+    // Should also have received a notification describing the new input device.
+    ASSERT_EQ(1U, mFakePolicy->getInputDevices().size());
+    InputDeviceInfo inputDevice = mFakePolicy->getInputDevices()[0];
+    ASSERT_EQ(0U, inputDevice.getLights().size());
+
+    RawLightInfo infoMonolight = {.id = 123,
+                                  .name = "mono_keyboard_backlight",
+                                  .maxBrightness = 255,
+                                  .flags = InputLightClass::BRIGHTNESS,
+                                  .path = ""};
+    mFakeEventHub->addRawLightInfo(/*rawId=*/123, std::move(infoMonolight));
+    mReader->sysfsNodeChanged("xyz");
+    mReader->loopOnce();
+
+    // Should also have received a notification describing the new recreated input device.
+    ASSERT_NO_FATAL_FAILURE(mFakePolicy->assertInputDevicesChanged());
+    inputDevice = mFakePolicy->getInputDevices()[0];
+    ASSERT_EQ(1U, inputDevice.getLights().size());
+}
+
 TEST_F(InputReaderTest, GetMergedInputDevices) {
     constexpr int32_t deviceId = END_RESERVED_ID + 1000;
     constexpr int32_t eventHubIds[2] = {END_RESERVED_ID, END_RESERVED_ID + 1};
diff --git a/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp b/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp
index 20242b1..baece3c 100644
--- a/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp
+++ b/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp
@@ -165,6 +165,10 @@
         return reader->getBluetoothAddress(deviceId);
     }
 
+    void sysfsNodeChanged(const std::string& sysfsNodePath) {
+        reader->sysfsNodeChanged(sysfsNodePath);
+    }
+
 private:
     std::unique_ptr<InputReaderInterface> reader;
 };
diff --git a/services/inputflinger/tests/fuzzers/MapperHelpers.h b/services/inputflinger/tests/fuzzers/MapperHelpers.h
index 2cb5cdf..c082128 100644
--- a/services/inputflinger/tests/fuzzers/MapperHelpers.h
+++ b/services/inputflinger/tests/fuzzers/MapperHelpers.h
@@ -217,6 +217,7 @@
     bool isDeviceEnabled(int32_t deviceId) const override { return mFdp->ConsumeBool(); }
     status_t enableDevice(int32_t deviceId) override { return mFdp->ConsumeIntegral<status_t>(); }
     status_t disableDevice(int32_t deviceId) override { return mFdp->ConsumeIntegral<status_t>(); }
+    void sysfsNodeChanged(const std::string& sysfsNodePath) override {}
 };
 
 class FuzzPointerController : public PointerControllerInterface {