Move libnative{bridge,loader} to art/

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

Bug: 137364733
Test: m
Change-Id: I9be7333d00fcd3f36cd80520e50a30ea840187ad

1 files changed, 178 insertions, 0 deletions

diff --git a/libnativeloader/native_loader_namespace.cpp b/libnativeloader/native_loader_namespace.cpp
new file mode 100644
index 0000000000..a81fddf0fa
--- /dev/null
+++ b/libnativeloader/native_loader_namespace.cpp
@@ -0,0 +1,178 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "nativeloader"
+
+#include "native_loader_namespace.h"
+
+#include <dlfcn.h>
+
+#include <functional>
+
+#include <android-base/strings.h>
+#include <log/log.h>
+#include <nativebridge/native_bridge.h>
+
+#include "nativeloader/dlext_namespaces.h"
+
+using android::base::Error;
+using android::base::Errorf;
+
+namespace android {
+
+namespace {
+
+constexpr const char* kDefaultNamespaceName = "default";
+constexpr const char* kPlatformNamespaceName = "platform";
+
+std::string GetLinkerError(bool is_bridged) {
+  const char* msg = is_bridged ? NativeBridgeGetError() : dlerror();
+  if (msg == nullptr) {
+    return "no error";
+  }
+  return std::string(msg);
+}
+
+}  // namespace
+
+Result<NativeLoaderNamespace> NativeLoaderNamespace::GetExportedNamespace(const std::string& name,
+                                                                          bool is_bridged) {
+  if (!is_bridged) {
+    auto raw = android_get_exported_namespace(name.c_str());
+    if (raw != nullptr) {
+      return NativeLoaderNamespace(name, raw);
+    }
+  } else {
+    auto raw = NativeBridgeGetExportedNamespace(name.c_str());
+    if (raw != nullptr) {
+      return NativeLoaderNamespace(name, raw);
+    }
+  }
+  return Errorf("namespace {} does not exist or exported", name);
+}
+
+// The platform namespace is called "default" for binaries in /system and
+// "platform" for those in the Runtime APEX. Try "platform" first since
+// "default" always exists.
+Result<NativeLoaderNamespace> NativeLoaderNamespace::GetPlatformNamespace(bool is_bridged) {
+  auto ns = GetExportedNamespace(kPlatformNamespaceName, is_bridged);
+  if (ns) return ns;
+  ns = GetExportedNamespace(kDefaultNamespaceName, is_bridged);
+  if (ns) return ns;
+
+  // If nothing is found, return NativeLoaderNamespace constructed from nullptr.
+  // nullptr also means default namespace to the linker.
+  if (!is_bridged) {
+    return NativeLoaderNamespace(kDefaultNamespaceName, static_cast<android_namespace_t*>(nullptr));
+  } else {
+    return NativeLoaderNamespace(kDefaultNamespaceName,
+                                 static_cast<native_bridge_namespace_t*>(nullptr));
+  }
+}
+
+Result<NativeLoaderNamespace> NativeLoaderNamespace::Create(
+    const std::string& name, const std::string& search_paths, const std::string& permitted_paths,
+    const NativeLoaderNamespace* parent, bool is_shared, bool is_greylist_enabled,
+    bool also_used_as_anonymous) {
+  bool is_bridged = false;
+  if (parent != nullptr) {
+    is_bridged = parent->IsBridged();
+  } else if (!search_paths.empty()) {
+    is_bridged = NativeBridgeIsPathSupported(search_paths.c_str());
+  }
+
+  // Fall back to the platform namespace if no parent is set.
+  auto platform_ns = GetPlatformNamespace(is_bridged);
+  if (!platform_ns) {
+    return platform_ns.error();
+  }
+  const NativeLoaderNamespace& effective_parent = parent != nullptr ? *parent : *platform_ns;
+
+  // All namespaces for apps are isolated
+  uint64_t type = ANDROID_NAMESPACE_TYPE_ISOLATED;
+
+  // The namespace is also used as the anonymous namespace
+  // which is used when the linker fails to determine the caller address
+  if (also_used_as_anonymous) {
+    type |= ANDROID_NAMESPACE_TYPE_ALSO_USED_AS_ANONYMOUS;
+  }
+
+  // Bundled apps have access to all system libraries that are currently loaded
+  // in the default namespace
+  if (is_shared) {
+    type |= ANDROID_NAMESPACE_TYPE_SHARED;
+  }
+  if (is_greylist_enabled) {
+    type |= ANDROID_NAMESPACE_TYPE_GREYLIST_ENABLED;
+  }
+
+  if (!is_bridged) {
+    android_namespace_t* raw =
+        android_create_namespace(name.c_str(), nullptr, search_paths.c_str(), type,
+                                 permitted_paths.c_str(), effective_parent.ToRawAndroidNamespace());
+    if (raw != nullptr) {
+      return NativeLoaderNamespace(name, raw);
+    }
+  } else {
+    native_bridge_namespace_t* raw = NativeBridgeCreateNamespace(
+        name.c_str(), nullptr, search_paths.c_str(), type, permitted_paths.c_str(),
+        effective_parent.ToRawNativeBridgeNamespace());
+    if (raw != nullptr) {
+      return NativeLoaderNamespace(name, raw);
+    }
+  }
+  return Errorf("failed to create {} namespace name:{}, search_paths:{}, permitted_paths:{}",
+                is_bridged ? "bridged" : "native", name, search_paths, permitted_paths);
+}
+
+Result<void> NativeLoaderNamespace::Link(const NativeLoaderNamespace& target,
+                                         const std::string& shared_libs) const {
+  LOG_ALWAYS_FATAL_IF(shared_libs.empty(), "empty share lib when linking %s to %s",
+                      this->name().c_str(), target.name().c_str());
+  if (!IsBridged()) {
+    if (android_link_namespaces(this->ToRawAndroidNamespace(), target.ToRawAndroidNamespace(),
+                                shared_libs.c_str())) {
+      return {};
+    }
+  } else {
+    if (NativeBridgeLinkNamespaces(this->ToRawNativeBridgeNamespace(),
+                                   target.ToRawNativeBridgeNamespace(), shared_libs.c_str())) {
+      return {};
+    }
+  }
+  return Error() << GetLinkerError(IsBridged());
+}
+
+Result<void*> NativeLoaderNamespace::Load(const char* lib_name) const {
+  if (!IsBridged()) {
+    android_dlextinfo extinfo;
+    extinfo.flags = ANDROID_DLEXT_USE_NAMESPACE;
+    extinfo.library_namespace = this->ToRawAndroidNamespace();
+    void* handle = android_dlopen_ext(lib_name, RTLD_NOW, &extinfo);
+    if (handle != nullptr) {
+      return handle;
+    }
+  } else {
+    void* handle =
+        NativeBridgeLoadLibraryExt(lib_name, RTLD_NOW, this->ToRawNativeBridgeNamespace());
+    if (handle != nullptr) {
+      return handle;
+    }
+  }
+  return Error() << GetLinkerError(IsBridged());
+}
+
+}  // namespace android