Default implementation for AudioControl AIDL HAL

Bug: b/170335834
Test: Built in target and ran `adb shell dumpsys
android.hardware.automotive.audiocontrol.IAudioControl/default` commands

Change-Id: Iccf5784fce7635c78ca8cc0f9066b4dc9f24b3bd

automotive/audiocontrol/aidl/default/Android.bp

@@ -0,0 +1,36 @@
+// Copyright (C) 2020 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.
+
+cc_binary {
+    name: "android.hardware.automotive.audiocontrol-service.example",
+    relative_install_path: "hw",
+    init_rc: ["audiocontrol-default.rc"],
+    vintf_fragments: ["audiocontrol-default.xml"],
+    vendor: true,
+    generated_headers: ["audio_policy_configuration_V7_0"],
+    generated_sources: ["audio_policy_configuration_V7_0"],
+    header_libs: ["libxsdc-utils"],
+    shared_libs: [
+        "android.hardware.automotive.audiocontrol-ndk_platform",
+        "libbase",
+        "libbinder_ndk",
+        "liblog",
+        "libcutils",
+        "libxml2",
+    ],
+    srcs: [
+        "AudioControl.cpp",
+        "main.cpp",
+    ],
+}

automotive/audiocontrol/aidl/default/AudioControl.cpp

@@ -0,0 +1,224 @@
+/*
+ * Copyright (C) 2020 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 "AudioControl.h"
+
+#include <aidl/android/hardware/automotive/audiocontrol/AudioFocusChange.h>
+#include <aidl/android/hardware/automotive/audiocontrol/IFocusListener.h>
+
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/strings.h>
+
+#include <audio_policy_configuration_V7_0.h>
+#include <private/android_filesystem_config.h>
+
+#include <stdio.h>
+
+namespace aidl::android::hardware::automotive::audiocontrol {
+
+using ::android::base::EqualsIgnoreCase;
+using ::android::base::ParseInt;
+using ::std::string;
+
+namespace xsd {
+using namespace audio::policy::configuration::V7_0;
+}
+
+namespace {
+const float kLowerBound = -1.0f;
+const float kUpperBound = 1.0f;
+bool checkCallerHasWritePermissions(int fd) {
+    // Double check that's only called by root - it should be be blocked at debug() level,
+    // but it doesn't hurt to make sure...
+    if (AIBinder_getCallingUid() != AID_ROOT) {
+        dprintf(fd, "Must be root\n");
+        return false;
+    }
+    return true;
+}
+
+bool isValidValue(float value) {
+    return (value >= kLowerBound) && (value <= kUpperBound);
+}
+
+bool safelyParseInt(string s, int* out) {
+    if (!ParseInt(s, out)) {
+        return false;
+    }
+    return true;
+}
+}  // namespace
+
+ndk::ScopedAStatus AudioControl::registerFocusListener(
+        const shared_ptr<IFocusListener>& in_listener) {
+    LOG(DEBUG) << "registering focus listener";
+
+    if (in_listener.get()) {
+        std::atomic_store(&mFocusListener, in_listener);
+    } else {
+        LOG(ERROR) << "Unexpected nullptr for listener resulting in no-op.";
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus AudioControl::setBalanceTowardRight(float value) {
+    if (isValidValue(value)) {
+        // Just log in this default mock implementation
+        LOG(INFO) << "Balance set to " << value;
+    } else {
+        LOG(ERROR) << "Balance value out of range -1 to 1 at " << value;
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus AudioControl::setFadeTowardFront(float value) {
+    if (isValidValue(value)) {
+        // Just log in this default mock implementation
+        LOG(INFO) << "Fader set to " << value;
+    } else {
+        LOG(ERROR) << "Fader value out of range -1 to 1 at " << value;
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus AudioControl::onAudioFocusChange(const string& in_usage, int32_t in_zoneId,
+                                                    AudioFocusChange in_focusChange) {
+    LOG(INFO) << "Focus changed: " << toString(in_focusChange).c_str() << " for usage "
+              << in_usage.c_str() << " in zone " << in_zoneId;
+    return ndk::ScopedAStatus::ok();
+}
+
+binder_status_t AudioControl::dump(int fd, const char** args, uint32_t numArgs) {
+    if (numArgs == 0) {
+        return dumpsys(fd);
+    }
+
+    string option = string(args[0]);
+    if (EqualsIgnoreCase(option, "--help")) {
+        return cmdHelp(fd);
+    } else if (EqualsIgnoreCase(option, "--request")) {
+        return cmdRequestFocus(fd, args, numArgs);
+    } else if (EqualsIgnoreCase(option, "--abandon")) {
+        return cmdAbandonFocus(fd, args, numArgs);
+    } else {
+        dprintf(fd, "Invalid option: %s\n", option.c_str());
+        return STATUS_BAD_VALUE;
+    }
+}
+
+binder_status_t AudioControl::dumpsys(int fd) {
+    if (mFocusListener == nullptr) {
+        dprintf(fd, "No focus listener registered\n");
+    } else {
+        dprintf(fd, "Focus listener registered\n");
+    }
+    return STATUS_OK;
+}
+
+binder_status_t AudioControl::cmdHelp(int fd) const {
+    dprintf(fd, "Usage: \n\n");
+    dprintf(fd, "[no args]: dumps focus listener status\n");
+    dprintf(fd, "--help: shows this help\n");
+    dprintf(fd,
+            "--request <USAGE> <ZONE_ID> <FOCUS_GAIN>: requests audio focus for specified "
+            "usage (string), audio zone ID (int), and focus gain type (int)\n");
+    dprintf(fd,
+            "--abandon <USAGE> <ZONE_ID>: abandons audio focus for specified usage (string) and "
+            "audio zone ID (int)\n");
+    dprintf(fd, "See audio_policy_configuration.xsd for valid AudioUsage values.\n");
+    return STATUS_OK;
+}
+
+binder_status_t AudioControl::cmdRequestFocus(int fd, const char** args, uint32_t numArgs) {
+    if (!checkCallerHasWritePermissions(fd)) {
+        return STATUS_PERMISSION_DENIED;
+    }
+    if (numArgs != 4) {
+        dprintf(fd,
+                "Invalid number of arguments: please provide --request <USAGE> <ZONE_ID> "
+                "<FOCUS_GAIN>\n");
+        return STATUS_BAD_VALUE;
+    }
+
+    string usage = string(args[1]);
+    if (xsd::stringToAudioUsage(usage) == xsd::AudioUsage::UNKNOWN) {
+        dprintf(fd,
+                "Unknown usage provided: %s. Please see audio_policy_configuration.xsd V7_0 "
+                "for supported values\n",
+                usage.c_str());
+        return STATUS_BAD_VALUE;
+    }
+
+    int zoneId;
+    if (!safelyParseInt(string(args[2]), &zoneId)) {
+        dprintf(fd, "Non-integer zoneId provided with request: %s\n", string(args[2]).c_str());
+        return STATUS_BAD_VALUE;
+    }
+
+    int focusGainValue;
+    if (!safelyParseInt(string(args[3]), &focusGainValue)) {
+        dprintf(fd, "Non-integer focusGain provided with request: %s\n", string(args[3]).c_str());
+        return STATUS_BAD_VALUE;
+    }
+    AudioFocusChange focusGain = AudioFocusChange(focusGainValue);
+
+    if (mFocusListener == nullptr) {
+        dprintf(fd, "Unable to request focus - no focus listener registered\n");
+        return STATUS_BAD_VALUE;
+    }
+
+    mFocusListener->requestAudioFocus(usage, zoneId, focusGain);
+    dprintf(fd, "Requested focus for usage %s, zoneId %d, and focusGain %d\n", usage.c_str(),
+            zoneId, focusGain);
+    return STATUS_OK;
+}
+
+binder_status_t AudioControl::cmdAbandonFocus(int fd, const char** args, uint32_t numArgs) {
+    if (!checkCallerHasWritePermissions(fd)) {
+        return STATUS_PERMISSION_DENIED;
+    }
+    if (numArgs != 3) {
+        dprintf(fd, "Invalid number of arguments: please provide --abandon <USAGE> <ZONE_ID>\n");
+        return STATUS_BAD_VALUE;
+    }
+
+    string usage = string(args[1]);
+    if (xsd::stringToAudioUsage(usage) == xsd::AudioUsage::UNKNOWN) {
+        dprintf(fd,
+                "Unknown usage provided: %s. Please see audio_policy_configuration.xsd V7_0 "
+                "for supported values\n",
+                usage.c_str());
+        return STATUS_BAD_VALUE;
+    }
+
+    int zoneId;
+    if (!safelyParseInt(string(args[2]), &zoneId)) {
+        dprintf(fd, "Non-integer zoneId provided with abandon: %s\n", string(args[2]).c_str());
+        return STATUS_BAD_VALUE;
+    }
+
+    if (mFocusListener == nullptr) {
+        dprintf(fd, "Unable to abandon focus - no focus listener registered\n");
+        return STATUS_BAD_VALUE;
+    }
+
+    mFocusListener->abandonAudioFocus(usage, zoneId);
+    dprintf(fd, "Abandoned focus for usage %s and zoneId %d\n", usage.c_str(), zoneId);
+    return STATUS_OK;
+}
+
+}  // namespace aidl::android::hardware::automotive::audiocontrol

automotive/audiocontrol/aidl/default/AudioControl.h

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+#ifndef ANDROID_HARDWARE_AUTOMOTIVE_AUDIOCONTROL_AUDIOCONTROL_H
+#define ANDROID_HARDWARE_AUTOMOTIVE_AUDIOCONTROL_AUDIOCONTROL_H
+
+#include <aidl/android/hardware/automotive/audiocontrol/AudioFocusChange.h>
+#include <aidl/android/hardware/automotive/audiocontrol/BnAudioControl.h>
+
+namespace aidl::android::hardware::automotive::audiocontrol {
+
+using ::std::shared_ptr;
+
+class AudioControl : public BnAudioControl {
+  public:
+    ndk::ScopedAStatus onAudioFocusChange(const std::string& in_usage, int32_t in_zoneId,
+                                          AudioFocusChange in_focusChange) override;
+    ndk::ScopedAStatus registerFocusListener(
+            const shared_ptr<IFocusListener>& in_listener) override;
+    ndk::ScopedAStatus setBalanceTowardRight(float in_value) override;
+    ndk::ScopedAStatus setFadeTowardFront(float in_value) override;
+    binder_status_t dump(int fd, const char** args, uint32_t numArgs) override;
+
+  private:
+    // This focus listener will only be used by this HAL instance to communicate with
+    // a single instance of CarAudioService. As such, it doesn't have explicit serialization.
+    // If a different AudioControl implementation were to have multiple threads leveraging this
+    // listener, then it should also include mutexes or make the listener atomic.
+    shared_ptr<IFocusListener> mFocusListener;
+
+    binder_status_t cmdHelp(int fd) const;
+    binder_status_t cmdRequestFocus(int fd, const char** args, uint32_t numArgs);
+    binder_status_t cmdAbandonFocus(int fd, const char** args, uint32_t numArgs);
+    binder_status_t dumpsys(int fd);
+};
+
+}  // namespace aidl::android::hardware::automotive::audiocontrol
+
+#endif  // ANDROID_HARDWARE_AUTOMOTIVE_AUDIOCONTROL_AUDIOCONTROL_H

automotive/audiocontrol/aidl/default/audiocontrol-default.rc

@@ -0,0 +1,4 @@
+service vendor.audiocontrol-default /vendor/bin/hw/android.hardware.automotive.audiocontrol-service.example
+    class hal
+    user audioserver
+    group system

automotive/audiocontrol/aidl/default/audiocontrol-default.xml

@@ -0,0 +1,6 @@
+<manifest version="1.0" type="device">
+    <hal format="aidl">
+        <name>android.hardware.automotive.audiocontrol</name>
+        <fqname>IAudioControl/default</fqname>
+    </hal>
+</manifest>

automotive/audiocontrol/aidl/default/main.cpp

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2020 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 "AudioControl.h"
+
+#include <android-base/logging.h>
+#include <android/binder_manager.h>
+#include <android/binder_process.h>
+
+using aidl::android::hardware::automotive::audiocontrol::AudioControl;
+
+int main() {
+    ABinderProcess_setThreadPoolMaxThreadCount(0);
+    std::shared_ptr<AudioControl> audioControl = ndk::SharedRefBase::make<AudioControl>();
+
+    const std::string instance = std::string() + AudioControl::descriptor + "/default";
+    binder_status_t status =
+            AServiceManager_addService(audioControl->asBinder().get(), instance.c_str());
+    CHECK(status == STATUS_OK);
+
+    ABinderProcess_joinThreadPool();
+    return EXIT_FAILURE;  // should not reach
+}