Move libnative{bridge,loader} to art/

This change moves system/core/libnative{bridge,loader} under art/.

Bug: 137364733
Test: m
Change-Id: I9be7333d00fcd3f36cd80520e50a30ea840187ad
diff --git a/libnativeloader/library_namespaces.cpp b/libnativeloader/library_namespaces.cpp
new file mode 100644
index 0000000..7246b97
--- /dev/null
+++ b/libnativeloader/library_namespaces.cpp
@@ -0,0 +1,319 @@
+/*
+ * Copyright (C) 2019 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 "library_namespaces.h"
+
+#include <dirent.h>
+#include <dlfcn.h>
+
+#include <regex>
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/macros.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <nativehelper/ScopedUtfChars.h>
+
+#include "nativeloader/dlext_namespaces.h"
+#include "public_libraries.h"
+#include "utils.h"
+
+using android::base::Error;
+
+namespace android::nativeloader {
+
+namespace {
+// The device may be configured to have the vendor libraries loaded to a separate namespace.
+// For historical reasons this namespace was named sphal but effectively it is intended
+// to use to load vendor libraries to separate namespace with controlled interface between
+// vendor and system namespaces.
+constexpr const char* kVendorNamespaceName = "sphal";
+constexpr const char* kVndkNamespaceName = "vndk";
+constexpr const char* kArtNamespaceName = "art";
+constexpr const char* kNeuralNetworksNamespaceName = "neuralnetworks";
+
+// classloader-namespace is a linker namespace that is created for the loaded
+// app. To be specific, it is created for the app classloader. When
+// System.load() is called from a Java class that is loaded from the
+// classloader, the classloader-namespace namespace associated with that
+// classloader is selected for dlopen. The namespace is configured so that its
+// search path is set to the app-local JNI directory and it is linked to the
+// platform namespace with the names of libs listed in the public.libraries.txt.
+// This way an app can only load its own JNI libraries along with the public libs.
+constexpr const char* kClassloaderNamespaceName = "classloader-namespace";
+// Same thing for vendor APKs.
+constexpr const char* kVendorClassloaderNamespaceName = "vendor-classloader-namespace";
+
+// (http://b/27588281) This is a workaround for apps using custom classloaders and calling
+// System.load() with an absolute path which is outside of the classloader library search path.
+// This list includes all directories app is allowed to access this way.
+constexpr const char* kWhitelistedDirectories = "/data:/mnt/expand";
+
+constexpr const char* kVendorLibPath = "/vendor/" LIB;
+constexpr const char* kProductLibPath = "/product/" LIB ":/system/product/" LIB;
+
+const std::regex kVendorDexPathRegex("(^|:)/vendor/");
+const std::regex kProductDexPathRegex("(^|:)(/system)?/product/");
+
+// Define origin of APK if it is from vendor partition or product partition
+typedef enum {
+  APK_ORIGIN_DEFAULT = 0,
+  APK_ORIGIN_VENDOR = 1,
+  APK_ORIGIN_PRODUCT = 2,
+} ApkOrigin;
+
+jobject GetParentClassLoader(JNIEnv* env, jobject class_loader) {
+  jclass class_loader_class = env->FindClass("java/lang/ClassLoader");
+  jmethodID get_parent =
+      env->GetMethodID(class_loader_class, "getParent", "()Ljava/lang/ClassLoader;");
+
+  return env->CallObjectMethod(class_loader, get_parent);
+}
+
+ApkOrigin GetApkOriginFromDexPath(JNIEnv* env, jstring dex_path) {
+  ApkOrigin apk_origin = APK_ORIGIN_DEFAULT;
+
+  if (dex_path != nullptr) {
+    ScopedUtfChars dex_path_utf_chars(env, dex_path);
+
+    if (std::regex_search(dex_path_utf_chars.c_str(), kVendorDexPathRegex)) {
+      apk_origin = APK_ORIGIN_VENDOR;
+    }
+
+    if (std::regex_search(dex_path_utf_chars.c_str(), kProductDexPathRegex)) {
+      LOG_ALWAYS_FATAL_IF(apk_origin == APK_ORIGIN_VENDOR,
+                          "Dex path contains both vendor and product partition : %s",
+                          dex_path_utf_chars.c_str());
+
+      apk_origin = APK_ORIGIN_PRODUCT;
+    }
+  }
+  return apk_origin;
+}
+
+}  // namespace
+
+void LibraryNamespaces::Initialize() {
+  // Once public namespace is initialized there is no
+  // point in running this code - it will have no effect
+  // on the current list of public libraries.
+  if (initialized_) {
+    return;
+  }
+
+  // android_init_namespaces() expects all the public libraries
+  // to be loaded so that they can be found by soname alone.
+  //
+  // TODO(dimitry): this is a bit misleading since we do not know
+  // if the vendor public library is going to be opened from /vendor/lib
+  // we might as well end up loading them from /system/lib or /product/lib
+  // For now we rely on CTS test to catch things like this but
+  // it should probably be addressed in the future.
+  for (const auto& soname : android::base::Split(preloadable_public_libraries(), ":")) {
+    LOG_ALWAYS_FATAL_IF(dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE) == nullptr,
+                        "Error preloading public library %s: %s", soname.c_str(), dlerror());
+  }
+}
+
+Result<NativeLoaderNamespace*> LibraryNamespaces::Create(JNIEnv* env, uint32_t target_sdk_version,
+                                                         jobject class_loader, bool is_shared,
+                                                         jstring dex_path,
+                                                         jstring java_library_path,
+                                                         jstring java_permitted_path) {
+  std::string library_path;  // empty string by default.
+
+  if (java_library_path != nullptr) {
+    ScopedUtfChars library_path_utf_chars(env, java_library_path);
+    library_path = library_path_utf_chars.c_str();
+  }
+
+  ApkOrigin apk_origin = GetApkOriginFromDexPath(env, dex_path);
+
+  // (http://b/27588281) This is a workaround for apps using custom
+  // classloaders and calling System.load() with an absolute path which
+  // is outside of the classloader library search path.
+  //
+  // This part effectively allows such a classloader to access anything
+  // under /data and /mnt/expand
+  std::string permitted_path = kWhitelistedDirectories;
+
+  if (java_permitted_path != nullptr) {
+    ScopedUtfChars path(env, java_permitted_path);
+    if (path.c_str() != nullptr && path.size() > 0) {
+      permitted_path = permitted_path + ":" + path.c_str();
+    }
+  }
+
+  LOG_ALWAYS_FATAL_IF(FindNamespaceByClassLoader(env, class_loader) != nullptr,
+                      "There is already a namespace associated with this classloader");
+
+  std::string system_exposed_libraries = default_public_libraries();
+  const char* namespace_name = kClassloaderNamespaceName;
+  bool unbundled_vendor_or_product_app = false;
+  if ((apk_origin == APK_ORIGIN_VENDOR ||
+       (apk_origin == APK_ORIGIN_PRODUCT && target_sdk_version > 29)) &&
+      !is_shared) {
+    unbundled_vendor_or_product_app = true;
+    // For vendor / product apks, give access to the vendor / product lib even though
+    // they are treated as unbundled; the libs and apks are still bundled
+    // together in the vendor / product partition.
+    const char* origin_partition;
+    const char* origin_lib_path;
+
+    switch (apk_origin) {
+      case APK_ORIGIN_VENDOR:
+        origin_partition = "vendor";
+        origin_lib_path = kVendorLibPath;
+        break;
+      case APK_ORIGIN_PRODUCT:
+        origin_partition = "product";
+        origin_lib_path = kProductLibPath;
+        break;
+      default:
+        origin_partition = "unknown";
+        origin_lib_path = "";
+    }
+    library_path = library_path + ":" + origin_lib_path;
+    permitted_path = permitted_path + ":" + origin_lib_path;
+
+    // Also give access to LLNDK libraries since they are available to vendors
+    system_exposed_libraries = system_exposed_libraries + ":" + llndk_libraries().c_str();
+
+    // Different name is useful for debugging
+    namespace_name = kVendorClassloaderNamespaceName;
+    ALOGD("classloader namespace configured for unbundled %s apk. library_path=%s",
+          origin_partition, library_path.c_str());
+  } else {
+    // extended public libraries are NOT available to vendor apks, otherwise it
+    // would be system->vendor violation.
+    if (!extended_public_libraries().empty()) {
+      system_exposed_libraries = system_exposed_libraries + ':' + extended_public_libraries();
+    }
+  }
+
+  // Create the app namespace
+  NativeLoaderNamespace* parent_ns = FindParentNamespaceByClassLoader(env, class_loader);
+  // Heuristic: the first classloader with non-empty library_path is assumed to
+  // be the main classloader for app
+  // TODO(b/139178525) remove this heuristic by determining this in LoadedApk (or its
+  // friends) and then passing it down to here.
+  bool is_main_classloader = app_main_namespace_ == nullptr && !library_path.empty();
+  // Policy: the namespace for the main classloader is also used as the
+  // anonymous namespace.
+  bool also_used_as_anonymous = is_main_classloader;
+  // Note: this function is executed with g_namespaces_mutex held, thus no
+  // racing here.
+  auto app_ns = NativeLoaderNamespace::Create(
+      namespace_name, library_path, permitted_path, parent_ns, is_shared,
+      target_sdk_version < 24 /* is_greylist_enabled */, also_used_as_anonymous);
+  if (!app_ns) {
+    return app_ns.error();
+  }
+  // ... and link to other namespaces to allow access to some public libraries
+  bool is_bridged = app_ns->IsBridged();
+
+  auto platform_ns = NativeLoaderNamespace::GetPlatformNamespace(is_bridged);
+  if (!platform_ns) {
+    return platform_ns.error();
+  }
+
+  auto linked = app_ns->Link(*platform_ns, system_exposed_libraries);
+  if (!linked) {
+    return linked.error();
+  }
+
+  auto art_ns = NativeLoaderNamespace::GetExportedNamespace(kArtNamespaceName, is_bridged);
+  // ART APEX does not exist on host, and under certain build conditions.
+  if (art_ns) {
+    linked = app_ns->Link(*art_ns, art_public_libraries());
+    if (!linked) {
+      return linked.error();
+    }
+  }
+
+  // Give access to NNAPI libraries (apex-updated LLNDK library).
+  auto nnapi_ns =
+      NativeLoaderNamespace::GetExportedNamespace(kNeuralNetworksNamespaceName, is_bridged);
+  if (nnapi_ns) {
+    linked = app_ns->Link(*nnapi_ns, neuralnetworks_public_libraries());
+    if (!linked) {
+      return linked.error();
+    }
+  }
+
+  // Give access to VNDK-SP libraries from the 'vndk' namespace.
+  if (unbundled_vendor_or_product_app && !vndksp_libraries().empty()) {
+    auto vndk_ns = NativeLoaderNamespace::GetExportedNamespace(kVndkNamespaceName, is_bridged);
+    if (vndk_ns) {
+      linked = app_ns->Link(*vndk_ns, vndksp_libraries());
+      if (!linked) {
+        return linked.error();
+      }
+    }
+  }
+
+  if (!vendor_public_libraries().empty()) {
+    auto vendor_ns = NativeLoaderNamespace::GetExportedNamespace(kVendorNamespaceName, is_bridged);
+    // when vendor_ns is not configured, link to the platform namespace
+    auto target_ns = vendor_ns ? vendor_ns : platform_ns;
+    if (target_ns) {
+      linked = app_ns->Link(*target_ns, vendor_public_libraries());
+      if (!linked) {
+        return linked.error();
+      }
+    }
+  }
+
+  namespaces_.push_back(std::make_pair(env->NewWeakGlobalRef(class_loader), *app_ns));
+  if (is_main_classloader) {
+    app_main_namespace_ = &(*app_ns);
+  }
+
+  return &(namespaces_.back().second);
+}
+
+NativeLoaderNamespace* LibraryNamespaces::FindNamespaceByClassLoader(JNIEnv* env,
+                                                                     jobject class_loader) {
+  auto it = std::find_if(namespaces_.begin(), namespaces_.end(),
+                         [&](const std::pair<jweak, NativeLoaderNamespace>& value) {
+                           return env->IsSameObject(value.first, class_loader);
+                         });
+  if (it != namespaces_.end()) {
+    return &it->second;
+  }
+
+  return nullptr;
+}
+
+NativeLoaderNamespace* LibraryNamespaces::FindParentNamespaceByClassLoader(JNIEnv* env,
+                                                                           jobject class_loader) {
+  jobject parent_class_loader = GetParentClassLoader(env, class_loader);
+
+  while (parent_class_loader != nullptr) {
+    NativeLoaderNamespace* ns;
+    if ((ns = FindNamespaceByClassLoader(env, parent_class_loader)) != nullptr) {
+      return ns;
+    }
+
+    parent_class_loader = GetParentClassLoader(env, parent_class_loader);
+  }
+
+  return nullptr;
+}
+
+}  // namespace android::nativeloader