1 files changed, 254 insertions, 0 deletions
diff --git a/libnativeloader/native_loader.cpp b/libnativeloader/native_loader.cpp
new file mode 100644
index 0000000000..6d3c057b9d
--- /dev/null
+++ b/libnativeloader/native_loader.cpp
@@ -0,0 +1,254 @@
+/*
+ * Copyright (C) 2015 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 "nativeloader"
+
+#include "nativeloader/native_loader.h"
+
+#include <dlfcn.h>
+#include <sys/types.h>
+
+#include <memory>
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/macros.h>
+#include <android-base/strings.h>
+#include <nativebridge/native_bridge.h>
+#include <nativehelper/ScopedUtfChars.h>
+
+#ifdef __ANDROID__
+#include <log/log.h>
+#include "library_namespaces.h"
+#include "nativeloader/dlext_namespaces.h"
+#endif
+
+namespace android {
+
+namespace {
+#if defined(__ANDROID__)
+using android::nativeloader::LibraryNamespaces;
+
+constexpr const char* kApexPath = "/apex/";
+
+std::mutex g_namespaces_mutex;
+LibraryNamespaces* g_namespaces = new LibraryNamespaces;
+
+android_namespace_t* FindExportedNamespace(const char* caller_location) {
+  std::string location = caller_location;
+  // Lots of implicit assumptions here: we expect `caller_location` to be of the form:
+  // /apex/com.android...modulename/...
+  //
+  // And we extract from it 'modulename', which is the name of the linker namespace.
+  if (android::base::StartsWith(location, kApexPath)) {
+    size_t slash_index = location.find_first_of('/', strlen(kApexPath));
+    LOG_ALWAYS_FATAL_IF((slash_index == std::string::npos),
+                        "Error finding namespace of apex: no slash in path %s", caller_location);
+    size_t dot_index = location.find_last_of('.', slash_index);
+    LOG_ALWAYS_FATAL_IF((dot_index == std::string::npos),
+                        "Error finding namespace of apex: no dot in apex name %s", caller_location);
+    std::string name = location.substr(dot_index + 1, slash_index - dot_index - 1);
+    android_namespace_t* boot_namespace = android_get_exported_namespace(name.c_str());
+    LOG_ALWAYS_FATAL_IF((boot_namespace == nullptr),
+                        "Error finding namespace of apex: no namespace called %s", name.c_str());
+    return boot_namespace;
+  }
+  return nullptr;
+}
+#endif  // #if defined(__ANDROID__)
+}  // namespace
+
+void InitializeNativeLoader() {
+#if defined(__ANDROID__)
+  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
+  g_namespaces->Initialize();
+#endif
+}
+
+void ResetNativeLoader() {
+#if defined(__ANDROID__)
+  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
+  g_namespaces->Reset();
+#endif
+}
+
+jstring CreateClassLoaderNamespace(JNIEnv* env, int32_t target_sdk_version, jobject class_loader,
+                                   bool is_shared, jstring dex_path, jstring library_path,
+                                   jstring permitted_path) {
+#if defined(__ANDROID__)
+  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
+  auto ns = g_namespaces->Create(env, target_sdk_version, class_loader, is_shared, dex_path,
+                                 library_path, permitted_path);
+  if (!ns) {
+    return env->NewStringUTF(ns.error().message().c_str());
+  }
+#else
+  UNUSED(env, target_sdk_version, class_loader, is_shared, dex_path, library_path, permitted_path);
+#endif
+  return nullptr;
+}
+
+void* OpenNativeLibrary(JNIEnv* env, int32_t target_sdk_version, const char* path,
+                        jobject class_loader, const char* caller_location, jstring library_path,
+                        bool* needs_native_bridge, char** error_msg) {
+#if defined(__ANDROID__)
+  UNUSED(target_sdk_version);
+  if (class_loader == nullptr) {
+    *needs_native_bridge = false;
+    if (caller_location != nullptr) {
+      android_namespace_t* boot_namespace = FindExportedNamespace(caller_location);
+      if (boot_namespace != nullptr) {
+        const android_dlextinfo dlextinfo = {
+            .flags = ANDROID_DLEXT_USE_NAMESPACE,
+            .library_namespace = boot_namespace,
+        };
+        void* handle = android_dlopen_ext(path, RTLD_NOW, &dlextinfo);
+        if (handle == nullptr) {
+          *error_msg = strdup(dlerror());
+        }
+        return handle;
+      }
+    }
+    void* handle = dlopen(path, RTLD_NOW);
+    if (handle == nullptr) {
+      *error_msg = strdup(dlerror());
+    }
+    return handle;
+  }
+
+  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
+  NativeLoaderNamespace* ns;
+
+  if ((ns = g_namespaces->FindNamespaceByClassLoader(env, class_loader)) == nullptr) {
+    // This is the case where the classloader was not created by ApplicationLoaders
+    // In this case we create an isolated not-shared namespace for it.
+    Result<NativeLoaderNamespace*> isolated_ns =
+        g_namespaces->Create(env, target_sdk_version, class_loader, false /* is_shared */, nullptr,
+                             library_path, nullptr);
+    if (!isolated_ns) {
+      *error_msg = strdup(isolated_ns.error().message().c_str());
+      return nullptr;
+    } else {
+      ns = *isolated_ns;
+    }
+  }
+
+  return OpenNativeLibraryInNamespace(ns, path, needs_native_bridge, error_msg);
+#else
+  UNUSED(env, target_sdk_version, class_loader, caller_location);
+
+  // Do some best effort to emulate library-path support. It will not
+  // work for dependencies.
+  //
+  // Note: null has a special meaning and must be preserved.
+  std::string c_library_path;  // Empty string by default.
+  if (library_path != nullptr && path != nullptr && path[0] != '/') {
+    ScopedUtfChars library_path_utf_chars(env, library_path);
+    c_library_path = library_path_utf_chars.c_str();
+  }
+
+  std::vector<std::string> library_paths = base::Split(c_library_path, ":");
+
+  for (const std::string& lib_path : library_paths) {
+    *needs_native_bridge = false;
+    const char* path_arg;
+    std::string complete_path;
+    if (path == nullptr) {
+      // Preserve null.
+      path_arg = nullptr;
+    } else {
+      complete_path = lib_path;
+      if (!complete_path.empty()) {
+        complete_path.append("/");
+      }
+      complete_path.append(path);
+      path_arg = complete_path.c_str();
+    }
+    void* handle = dlopen(path_arg, RTLD_NOW);
+    if (handle != nullptr) {
+      return handle;
+    }
+    if (NativeBridgeIsSupported(path_arg)) {
+      *needs_native_bridge = true;
+      handle = NativeBridgeLoadLibrary(path_arg, RTLD_NOW);
+      if (handle != nullptr) {
+        return handle;
+      }
+      *error_msg = strdup(NativeBridgeGetError());
+    } else {
+      *error_msg = strdup(dlerror());
+    }
+  }
+  return nullptr;
+#endif
+}
+
+bool CloseNativeLibrary(void* handle, const bool needs_native_bridge, char** error_msg) {
+  bool success;
+  if (needs_native_bridge) {
+    success = (NativeBridgeUnloadLibrary(handle) == 0);
+    if (!success) {
+      *error_msg = strdup(NativeBridgeGetError());
+    }
+  } else {
+    success = (dlclose(handle) == 0);
+    if (!success) {
+      *error_msg = strdup(dlerror());
+    }
+  }
+
+  return success;
+}
+
+void NativeLoaderFreeErrorMessage(char* msg) {
+  // The error messages get allocated through strdup, so we must call free on them.
+  free(msg);
+}
+
+#if defined(__ANDROID__)
+void* OpenNativeLibraryInNamespace(NativeLoaderNamespace* ns, const char* path,
+                                   bool* needs_native_bridge, char** error_msg) {
+  auto handle = ns->Load(path);
+  if (!handle && error_msg != nullptr) {
+    *error_msg = strdup(handle.error().message().c_str());
+  }
+  if (needs_native_bridge != nullptr) {
+    *needs_native_bridge = ns->IsBridged();
+  }
+  return handle ? *handle : nullptr;
+}
+
+// native_bridge_namespaces are not supported for callers of this function.
+// This function will return nullptr in the case when application is running
+// on native bridge.
+android_namespace_t* FindNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
+  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
+  NativeLoaderNamespace* ns = g_namespaces->FindNamespaceByClassLoader(env, class_loader);
+  if (ns != nullptr && !ns->IsBridged()) {
+    return ns->ToRawAndroidNamespace();
+  }
+  return nullptr;
+}
+
+NativeLoaderNamespace* FindNativeLoaderNamespaceByClassLoader(JNIEnv* env, jobject class_loader) {
+  std::lock_guard<std::mutex> guard(g_namespaces_mutex);
+  return g_namespaces->FindNamespaceByClassLoader(env, class_loader);
+}
+#endif
+
+};  // namespace android