Add initial batch of inputFlinger fuzzers

This batch of fuzzers is focused on the input Mappers. These fuzzers are
not host_supported, and must be run on-device. Followup CLs containing
additional inputflinger fuzzers will rely on the FuzzContainer.h and
MapperHelpers.h header files.

Fuzzers included:
 - CursorInputFuzzer
 - KeyboardInputFuzzer
 - MultiTouchInputFuzzer
 - SwitchInputFuzzer

Test: Tested on a pixel 3a with HWASAN. Accurate % coverage information is
      not available due to the large number of shared libraries included
      in runs built with hwasan interfering with PC Count information
      (increasing the total PC count to ~682,000).

Summary of updates:

Coverage improvements: 75% to 82%

Design changes:
[1] Refactored
 - CursorInputFuzzer
 - KeyboardInputFuzzer
 - MultiTouchInputFuzzer
 - SwitchInputFuzzer
in order to generate event as a combination of valid and invalid input.

[2] Used FuzzedDataProvider to generate values for events.

Signed-off-by: Michael Ensing <michael.ensing@leviathansecurity.com>
Change-Id: Id39205c691f54c516f8a452293cb098382019335
diff --git a/services/inputflinger/tests/fuzzers/MultiTouchInputFuzzer.cpp b/services/inputflinger/tests/fuzzers/MultiTouchInputFuzzer.cpp
new file mode 100644
index 0000000..59b0642
--- /dev/null
+++ b/services/inputflinger/tests/fuzzers/MultiTouchInputFuzzer.cpp
@@ -0,0 +1,134 @@
+/*
+ * Copyright 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <FuzzContainer.h>
+#include <MultiTouchInputMapper.h>
+#include <fuzzer/FuzzedDataProvider.h>
+
+namespace android {
+
+const int32_t kMaxKeycodes = 100;
+
+static void addProperty(FuzzContainer& fuzzer, std::shared_ptr<FuzzedDataProvider> fdp) {
+    // Pick a random property to set for the mapper to have set.
+    fdp->PickValueInArray<std::function<void()>>(
+            {[&]() -> void { fuzzer.addProperty("touch.deviceType", "touchScreen"); },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.deviceType", fdp->ConsumeRandomLengthString(8).data());
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.size.scale", fdp->ConsumeRandomLengthString(8).data());
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.size.bias", fdp->ConsumeRandomLengthString(8).data());
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.size.isSummed",
+                                    fdp->ConsumeRandomLengthString(8).data());
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.size.calibration",
+                                    fdp->ConsumeRandomLengthString(8).data());
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.pressure.scale",
+                                    fdp->ConsumeRandomLengthString(8).data());
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.size.calibration",
+                                    fdp->ConsumeBool() ? "diameter" : "area");
+             },
+             [&]() -> void {
+                 fuzzer.addProperty("touch.pressure.calibration",
+                                    fdp->ConsumeRandomLengthString(8).data());
+             }})();
+}
+
+extern "C" int LLVMFuzzerTestOneInput(uint8_t* data, size_t size) {
+    std::shared_ptr<FuzzedDataProvider> fdp = std::make_shared<FuzzedDataProvider>(data, size);
+    FuzzContainer fuzzer(fdp);
+
+    MultiTouchInputMapper& mapper = fuzzer.getMapper<MultiTouchInputMapper>();
+    auto policyConfig = fuzzer.getPolicyConfig();
+
+    // Loop through mapper operations until randomness is exhausted.
+    while (fdp->remaining_bytes() > 0) {
+        fdp->PickValueInArray<std::function<void()>>({
+                [&]() -> void { addProperty(fuzzer, fdp); },
+                [&]() -> void {
+                    std::string dump;
+                    mapper.dump(dump);
+                },
+                [&]() -> void {
+                    InputDeviceInfo info;
+                    mapper.populateDeviceInfo(&info);
+                },
+                [&]() -> void { mapper.getSources(); },
+                [&]() -> void {
+                    mapper.configure(fdp->ConsumeIntegral<nsecs_t>(), &policyConfig,
+                                     fdp->ConsumeIntegral<uint32_t>());
+                },
+                [&]() -> void { mapper.reset(fdp->ConsumeIntegral<nsecs_t>()); },
+                [&]() -> void {
+                    int32_t type = fdp->ConsumeBool() ? fdp->PickValueInArray(kValidTypes)
+                                                      : fdp->ConsumeIntegral<int32_t>();
+                    int32_t code = fdp->ConsumeBool() ? fdp->PickValueInArray(kValidCodes)
+                                                      : fdp->ConsumeIntegral<int32_t>();
+                    RawEvent rawEvent{fdp->ConsumeIntegral<nsecs_t>(),
+                                      fdp->ConsumeIntegral<nsecs_t>(),
+                                      fdp->ConsumeIntegral<int32_t>(),
+                                      type,
+                                      code,
+                                      fdp->ConsumeIntegral<int32_t>()};
+                    mapper.process(&rawEvent);
+                },
+                [&]() -> void {
+                    mapper.getKeyCodeState(fdp->ConsumeIntegral<uint32_t>(),
+                                           fdp->ConsumeIntegral<int32_t>());
+                },
+                [&]() -> void {
+                    mapper.getScanCodeState(fdp->ConsumeIntegral<uint32_t>(),
+                                            fdp->ConsumeIntegral<int32_t>());
+                },
+                [&]() -> void {
+                    std::vector<int32_t> keyCodes;
+                    int32_t numBytes = fdp->ConsumeIntegralInRange<int32_t>(0, kMaxKeycodes);
+                    for (int32_t i = 0; i < numBytes; ++i) {
+                        keyCodes.push_back(fdp->ConsumeIntegral<int32_t>());
+                    }
+                    mapper.markSupportedKeyCodes(fdp->ConsumeIntegral<uint32_t>(), keyCodes,
+                                                 nullptr);
+                },
+                [&]() -> void {
+                    mapper.cancelTouch(fdp->ConsumeIntegral<nsecs_t>(),
+                                       fdp->ConsumeIntegral<nsecs_t>());
+                },
+                [&]() -> void { mapper.timeoutExpired(fdp->ConsumeIntegral<nsecs_t>()); },
+                [&]() -> void {
+                    StylusState state{fdp->ConsumeIntegral<nsecs_t>(),
+                                      fdp->ConsumeFloatingPoint<float>(),
+                                      fdp->ConsumeIntegral<uint32_t>(),
+                                      fdp->ConsumeIntegral<int32_t>()};
+                    mapper.updateExternalStylusState(state);
+                },
+                [&]() -> void { mapper.getAssociatedDisplayId(); },
+        })();
+    }
+
+    return 0;
+}
+
+} // namespace android