Audio VTS: Enforce policy configuration format

Validate the audio_policy_configuration.xml supplied in /vendor against
the format schema.

Test: Run the VTS test on target
Test: vts-tradefed run commandAndExit vts --skip-all-system-status-check --primary-abi-only --skip-preconditions --module VtsHalAudioV2_0Target -t CheckConfig.audioPolicyConfigurationValidation
Bug: 35700978
Change-Id: I800e692a6ff4f64655007c33af7e34d879ee1132
Signed-off-by: Kevin Rocard <krocard@google.com>

audio/2.0/vts/functional/Android.mk

@@ -21,6 +21,8 @@ LOCAL_MODULE := VtsHalAudioV2_0TargetTest
 LOCAL_CPPFLAGS := -O0 -g -Wall -Wextra -Werror
 LOCAL_SRC_FILES := \
     AudioPrimaryHidlHalTest.cpp \
+    ValidateAudioConfiguration.cpp \
+    utility/ValidateXml.cpp
 
 LOCAL_C_INCLUDES := external/libxml2/include
 

audio/2.0/vts/functional/ValidateAudioConfiguration.cpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2017 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 "utility/ValidateXml.h"
+
+TEST(CheckConfig, audioPolicyConfigurationValidation) {
+    ASSERT_VALID_XML("/vendor/etc/audio_policy_configuration.xml",
+                     "/data/local/tmp/audio_policy_configuration.xsd");
+}

audio/2.0/vts/functional/utility/ValidateXml.cpp

@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2017 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.
+ */
+
+#define LOG_TAG "ValidateAudioConfig"
+#include <utils/Log.h>
+
+#define LIBXML_SCHEMAS_ENABLED
+#include <libxml/xmlschemastypes.h>
+#define LIBXML_XINCLUDE_ENABLED
+#include <libxml/xinclude.h>
+
+#include <memory>
+#include <string>
+
+#include "ValidateXml.h"
+
+namespace android {
+namespace hardware {
+namespace audio {
+namespace test {
+
+/** Map libxml2 structures to their corresponding deleters. */
+template <class T>
+constexpr void (*xmlDeleter)(T* t);
+template <>
+constexpr auto xmlDeleter<xmlSchema> = xmlSchemaFree;
+template <>
+constexpr auto xmlDeleter<xmlDoc> = xmlFreeDoc;
+template <>
+constexpr auto xmlDeleter<xmlSchemaParserCtxt> = xmlSchemaFreeParserCtxt;
+template <>
+constexpr auto xmlDeleter<xmlSchemaValidCtxt> = xmlSchemaFreeValidCtxt;
+
+/** @return a unique_ptr with the correct deleter for the libxml2 object. */
+template <class T>
+constexpr auto make_xmlUnique(T* t) {
+    // Wrap deleter in lambda to enable empty base optimization
+    auto deleter = [](T* t) { xmlDeleter<T>(t); };
+    return std::unique_ptr<T, decltype(deleter)>{t, deleter};
+}
+
+/** Class that handles libxml2 initialization and cleanup. NOT THREAD SAFE*/
+struct Libxml2Global {
+    Libxml2Global() {
+        xmlLineNumbersDefault(1);  // Better error message
+        xmlSetGenericErrorFunc(this, errorCb);
+    }
+    ~Libxml2Global() {
+        // TODO: check if all those cleanup are needed
+        xmlSetGenericErrorFunc(nullptr, nullptr);
+        xmlSchemaCleanupTypes();
+        xmlCleanupParser();
+        xmlCleanupThreads();
+    }
+
+    const std::string& getErrors() { return errors; }
+
+   private:
+    static void errorCb(void* ctxt, const char* msg, ...) {
+        auto* self = static_cast<Libxml2Global*>(ctxt);
+        va_list args;
+        va_start(args, msg);
+
+        char* formatedMsg;
+        if (vasprintf(&formatedMsg, msg, args) >= 0) {
+            LOG_PRI(ANDROID_LOG_ERROR, LOG_TAG, "%s", formatedMsg);
+            self->errors += "Error: ";
+            self->errors += formatedMsg;
+        }
+        free(formatedMsg);
+
+        va_end(args);
+    }
+    std::string errors;
+};
+
+::testing::AssertionResult validateXml(const char* xmlFilePathExpr,
+                                       const char* xsdFilePathExpr,
+                                       const char* xmlFilePath,
+                                       const char* xsdFilePath) {
+    Libxml2Global libxml2;
+
+    auto context = [&]() {
+        return std::string() + "    While validating: " + xmlFilePathExpr +
+               "\n          Which is: " + xmlFilePath +
+               "\nAgainst the schema: " + xsdFilePathExpr +
+               "\n          Which is: " + xsdFilePath + "Libxml2 errors\n" +
+               libxml2.getErrors();
+    };
+
+    auto schemaParserCtxt = make_xmlUnique(xmlSchemaNewParserCtxt(xsdFilePath));
+    auto schema = make_xmlUnique(xmlSchemaParse(schemaParserCtxt.get()));
+    if (schema == nullptr) {
+        return ::testing::AssertionFailure() << "Failed to parse schema (xsd)\n"
+                                             << context();
+    }
+
+    auto doc = make_xmlUnique(xmlReadFile(xmlFilePath, nullptr, 0));
+    if (doc == nullptr) {
+        return ::testing::AssertionFailure() << "Failed to parse xml\n"
+                                             << context();
+    }
+
+    if (xmlXIncludeProcess(doc.get()) == -1) {
+        return ::testing::AssertionFailure()
+               << "Failed to resolve xincludes in xml\n"
+               << context();
+    }
+
+    auto schemaCtxt = make_xmlUnique(xmlSchemaNewValidCtxt(schema.get()));
+    int ret = xmlSchemaValidateDoc(schemaCtxt.get(), doc.get());
+    if (ret > 0) {
+        return ::testing::AssertionFailure()
+               << "xml is not valid according to the xsd.\n"
+               << context();
+    }
+    if (ret < 0) {
+        return ::testing::AssertionFailure() << "Internal or API error\n"
+                                             << context();
+    }
+
+    return ::testing::AssertionSuccess();
+}
+
+}  // namespace test
+}  // namespace audio
+}  // namespace hardware
+}  // namespace android

audio/2.0/vts/functional/utility/ValidateXml.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2017 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_AUDIO_TEST_VALIDATEXML
+#define ANDROID_HARDWARE_AUDIO_TEST_VALIDATEXML
+
+#include <gtest/gtest.h>
+
+namespace android {
+namespace hardware {
+namespace audio {
+namespace test {
+
+/** Validate the provided XmlFile with the provided xsdFile.
+ * Intended to use with ASSERT_PRED_FORMAT2 as such:
+ *   ASSERT_PRED_FORMAT2(validateXml, pathToXml, pathToXsd);
+ * See ASSERT_VALID_XML for a helper macro.
+ */
+::testing::AssertionResult validateXml(const char* xmlFilePathExpr,
+                                       const char* xsdFilePathExpr,
+                                       const char* xmlFilePath,
+                                       const char* xsdPathName);
+
+/** Helper gtest ASSERT to test xml validity against an xsd. */
+#define ASSERT_VALID_XML(xmlFilePath, xsdFilePath)                     \
+    ASSERT_PRED_FORMAT2(::android::hardware::audio::test::validateXml, \
+                        xmlFilePath, xsdFilePath)
+
+}  // namespace test
+}  // namespace audio
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_AUDIO_TEST_VALIDATEXML