Merge SP1A.210222.001

Change-Id: If3509f3a660e820f4c8c0b29e007faa868e1f089

1 files changed, 448 insertions, 0 deletions

diff --git a/cmds/idmap2/libidmap2/ResourceContainer.cpp b/cmds/idmap2/libidmap2/ResourceContainer.cpp
new file mode 100644
index 000000000000..9147ccaaa17a
--- /dev/null
+++ b/cmds/idmap2/libidmap2/ResourceContainer.cpp
@@ -0,0 +1,448 @@
+/*
+ * Copyright (C) 2021 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 "idmap2/ResourceContainer.h"
+
+#include "androidfw/ApkAssets.h"
+#include "androidfw/AssetManager.h"
+#include "androidfw/Util.h"
+#include "idmap2/FabricatedOverlay.h"
+#include "idmap2/XmlParser.h"
+
+namespace android::idmap2 {
+namespace {
+#define REWRITE_PACKAGE(resid, package_id) \
+  (((resid)&0x00ffffffU) | (((uint32_t)(package_id)) << 24U))
+
+#define EXTRACT_PACKAGE(resid) ((0xff000000 & (resid)) >> 24)
+
+constexpr ResourceId kAttrName = 0x01010003;
+constexpr ResourceId kAttrResourcesMap = 0x01010609;
+constexpr ResourceId kAttrTargetName = 0x0101044d;
+constexpr ResourceId kAttrTargetPackage = 0x01010021;
+
+// idmap version 0x01 naively assumes that the package to use is always the first ResTable_package
+// in the resources.arsc blob. In most cases, there is only a single ResTable_package anyway, so
+// this assumption tends to work out. That said, the correct thing to do is to scan
+// resources.arsc for a package with a given name as read from the package manifest instead of
+// relying on a hard-coded index. This however requires storing the package name in the idmap
+// header, which in turn requires incrementing the idmap version. Because the initial version of
+// idmap2 is compatible with idmap, this will have to wait for now.
+const LoadedPackage* GetPackageAtIndex0(const LoadedArsc* loaded_arsc) {
+  const std::vector<std::unique_ptr<const LoadedPackage>>& packages = loaded_arsc->GetPackages();
+  if (packages.empty()) {
+    return nullptr;
+  }
+  return loaded_arsc->GetPackageById(packages[0]->GetPackageId());
+}
+
+Result<uint32_t> CalculateCrc(const ZipAssetsProvider* zip_assets) {
+  constexpr const char* kResourcesArsc = "resources.arsc";
+  std::optional<uint32_t> res_crc = zip_assets->GetCrc(kResourcesArsc);
+  if (!res_crc) {
+    return Error("failed to get CRC for '%s'", kResourcesArsc);
+  }
+
+  constexpr const char* kManifest = "AndroidManifest.xml";
+  std::optional<uint32_t> man_crc = zip_assets->GetCrc(kManifest);
+  if (!man_crc) {
+    return Error("failed to get CRC for '%s'", kManifest);
+  }
+
+  return *res_crc ^ *man_crc;
+}
+
+Result<XmlParser> OpenXmlParser(const std::string& entry_path, const ZipAssetsProvider* zip) {
+  auto manifest = zip->Open(entry_path);
+  if (manifest == nullptr) {
+    return Error("failed to find %s ", entry_path.c_str());
+  }
+
+  auto size = manifest->getLength();
+  auto buffer = manifest->getIncFsBuffer(true /* aligned */).convert<uint8_t>();
+  if (!buffer.verify(size)) {
+    return Error("failed to read entire %s", entry_path.c_str());
+  }
+
+  return XmlParser::Create(buffer.unsafe_ptr(), size, true /* copyData */);
+}
+
+Result<XmlParser> OpenXmlParser(ResourceId id, const ZipAssetsProvider* zip,
+                                const AssetManager2* am) {
+  const auto ref_table = am->GetDynamicRefTableForCookie(0);
+  if (ref_table == nullptr) {
+    return Error("failed to find dynamic ref table for cookie 0");
+  }
+
+  ref_table->lookupResourceId(&id);
+  auto value = am->GetResource(id);
+  if (!value.has_value()) {
+    return Error("failed to find resource for id 0x%08x", id);
+  }
+
+  if (value->type != Res_value::TYPE_STRING) {
+    return Error("resource for is 0x%08x is not a file", id);
+  }
+
+  auto string_pool = am->GetStringPoolForCookie(value->cookie);
+  auto file = string_pool->string8ObjectAt(value->data);
+  if (!file.has_value()) {
+    return Error("failed to find string for index %d", value->data);
+  }
+
+  return OpenXmlParser(file->c_str(), zip);
+}
+
+Result<OverlayManifestInfo> ExtractOverlayManifestInfo(const ZipAssetsProvider* zip,
+                                                       const std::string& name) {
+  Result<XmlParser> xml = OpenXmlParser("AndroidManifest.xml", zip);
+  if (!xml) {
+    return xml.GetError();
+  }
+
+  auto manifest_it = xml->tree_iterator();
+  if (manifest_it->event() != XmlParser::Event::START_TAG || manifest_it->name() != "manifest") {
+    return Error("root element tag is not <manifest> in AndroidManifest.xml");
+  }
+
+  std::string package_name;
+  if (auto result_str = manifest_it->GetAttributeStringValue("package")) {
+    package_name = *result_str;
+  } else {
+    return result_str.GetError();
+  }
+
+  for (auto&& it : manifest_it) {
+    if (it.event() != XmlParser::Event::START_TAG || it.name() != "overlay") {
+      continue;
+    }
+
+    OverlayManifestInfo info{};
+    info.package_name = package_name;
+    if (auto result_str = it.GetAttributeStringValue(kAttrName, "android:name")) {
+      if (*result_str != name) {
+        // A value for android:name was found, but either a the name does not match the requested
+        // name, or an <overlay> tag with no name was requested.
+        continue;
+      }
+      info.name = *result_str;
+    } else if (!name.empty()) {
+      // This tag does not have a value for android:name, but an <overlay> tag with a specific name
+      // has been requested.
+      continue;
+    }
+
+    if (auto result_str = it.GetAttributeStringValue(kAttrTargetPackage, "android:targetPackage")) {
+      info.target_package = *result_str;
+    } else {
+      return Error("android:targetPackage missing from <overlay> in AndroidManifest.xml");
+    }
+
+    if (auto result_str = it.GetAttributeStringValue(kAttrTargetName, "android:targetName")) {
+      info.target_name = *result_str;
+    }
+
+    if (auto result_value = it.GetAttributeValue(kAttrResourcesMap, "android:resourcesMap")) {
+      if (utils::IsReference((*result_value).dataType)) {
+        info.resource_mapping = (*result_value).data;
+      } else {
+        return Error("android:resourcesMap is not a reference in AndroidManifest.xml");
+      }
+    }
+    return info;
+  }
+
+  return Error("<overlay> with android:name \"%s\" missing from AndroidManifest.xml", name.c_str());
+}
+
+Result<OverlayData> CreateResourceMapping(ResourceId id, const ZipAssetsProvider* zip,
+                                          const AssetManager2* overlay_am,
+                                          const LoadedArsc* overlay_arsc,
+                                          const LoadedPackage* overlay_package) {
+  auto parser = OpenXmlParser(id, zip, overlay_am);
+  if (!parser) {
+    return parser.GetError();
+  }
+
+  OverlayData overlay_data{};
+  const uint32_t string_pool_offset = overlay_arsc->GetStringPool()->size();
+  const uint8_t package_id = overlay_package->GetPackageId();
+  auto root_it = parser->tree_iterator();
+  if (root_it->event() != XmlParser::Event::START_TAG || root_it->name() != "overlay") {
+    return Error("root element is not <overlay> tag");
+  }
+
+  auto overlay_it_end = root_it.end();
+  for (auto overlay_it = root_it.begin(); overlay_it != overlay_it_end; ++overlay_it) {
+    if (overlay_it->event() == XmlParser::Event::BAD_DOCUMENT) {
+      return Error("failed to parse overlay xml document");
+    }
+
+    if (overlay_it->event() != XmlParser::Event::START_TAG) {
+      continue;
+    }
+
+    if (overlay_it->name() != "item") {
+      return Error("unexpected tag <%s> in <overlay>", overlay_it->name().c_str());
+    }
+
+    Result<std::string> target_resource = overlay_it->GetAttributeStringValue("target");
+    if (!target_resource) {
+      return Error(R"(<item> tag missing expected attribute "target")");
+    }
+
+    Result<android::Res_value> overlay_resource = overlay_it->GetAttributeValue("value");
+    if (!overlay_resource) {
+      return Error(R"(<item> tag missing expected attribute "value")");
+    }
+
+    if (overlay_resource->dataType == Res_value::TYPE_STRING) {
+      overlay_resource->data += string_pool_offset;
+    }
+
+    if (utils::IsReference(overlay_resource->dataType)) {
+      // Only rewrite resources defined within the overlay package to their corresponding target
+      // resource ids at runtime.
+      bool rewrite_id = package_id == EXTRACT_PACKAGE(overlay_resource->data);
+      overlay_data.pairs.emplace_back(OverlayData::Value{
+          *target_resource, OverlayData::ResourceIdValue{overlay_resource->data, rewrite_id}});
+    } else {
+      overlay_data.pairs.emplace_back(
+          OverlayData::Value{*target_resource, TargetValue{.data_type = overlay_resource->dataType,
+                                                           .data_value = overlay_resource->data}});
+    }
+  }
+
+  const auto& string_pool = parser->get_strings();
+  const uint32_t string_pool_data_length = string_pool.bytes();
+  overlay_data.string_pool_data = OverlayData::InlineStringPoolData{
+      .data = std::unique_ptr<uint8_t[]>(new uint8_t[string_pool_data_length]),
+      .data_length = string_pool_data_length,
+      .string_pool_offset = string_pool_offset,
+  };
+
+  // Overlays should not be incrementally installed, so calling unsafe_ptr is fine here.
+  memcpy(overlay_data.string_pool_data->data.get(), string_pool.data().unsafe_ptr(),
+         string_pool_data_length);
+  return overlay_data;
+}
+
+OverlayData CreateResourceMappingLegacy(const AssetManager2* overlay_am,
+                                        const LoadedPackage* overlay_package) {
+  OverlayData overlay_data{};
+  for (const ResourceId overlay_resid : *overlay_package) {
+    if (auto name = utils::ResToTypeEntryName(*overlay_am, overlay_resid)) {
+      // Disable rewriting. Overlays did not support internal references before
+      // android:resourcesMap. Do not introduce new behavior.
+      overlay_data.pairs.emplace_back(OverlayData::Value{
+          *name, OverlayData::ResourceIdValue{overlay_resid, false /* rewrite_id */}});
+    }
+  }
+  return overlay_data;
+}
+
+struct ResState {
+  std::unique_ptr<ApkAssets> apk_assets;
+  const LoadedArsc* arsc;
+  const LoadedPackage* package;
+  std::unique_ptr<AssetManager2> am;
+  ZipAssetsProvider* zip_assets;
+
+  static Result<ResState> Initialize(std::unique_ptr<ZipAssetsProvider> zip) {
+    ResState state;
+    state.zip_assets = zip.get();
+    if ((state.apk_assets = ApkAssets::Load(std::move(zip))) == nullptr) {
+      return Error("failed to load apk asset");
+    }
+
+    if ((state.arsc = state.apk_assets->GetLoadedArsc()) == nullptr) {
+      return Error("failed to retrieve loaded arsc");
+    }
+
+    if ((state.package = GetPackageAtIndex0(state.arsc)) == nullptr) {
+      return Error("failed to retrieve loaded package at index 0");
+    }
+
+    state.am = std::make_unique<AssetManager2>();
+    if (!state.am->SetApkAssets({state.apk_assets.get()})) {
+      return Error("failed to create asset manager");
+    }
+
+    return state;
+  }
+};
+
+}  // namespace
+
+struct ApkResourceContainer : public TargetResourceContainer, public OverlayResourceContainer {
+  static Result<std::unique_ptr<ApkResourceContainer>> FromPath(const std::string& path);
+
+  // inherited from TargetResourceContainer
+  Result<bool> DefinesOverlayable() const override;
+  Result<const android::OverlayableInfo*> GetOverlayableInfo(ResourceId id) const override;
+  Result<ResourceId> GetResourceId(const std::string& name) const override;
+
+  // inherited from OverlayResourceContainer
+  Result<OverlayData> GetOverlayData(const OverlayManifestInfo& info) const override;
+  Result<OverlayManifestInfo> FindOverlayInfo(const std::string& name) const override;
+
+  // inherited from ResourceContainer
+  Result<uint32_t> GetCrc() const override;
+  Result<std::string> GetResourceName(ResourceId id) const override;
+  const std::string& GetPath() const override;
+
+  ~ApkResourceContainer() override = default;
+
+ private:
+  ApkResourceContainer(std::unique_ptr<ZipAssetsProvider> zip_assets, std::string path);
+
+  Result<const ResState*> GetState() const;
+  ZipAssetsProvider* GetZipAssets() const;
+
+  mutable std::variant<std::unique_ptr<ZipAssetsProvider>, ResState> state_;
+  std::string path_;
+};
+
+ApkResourceContainer::ApkResourceContainer(std::unique_ptr<ZipAssetsProvider> zip_assets,
+                                           std::string path)
+    : state_(std::move(zip_assets)), path_(std::move(path)) {
+}
+
+Result<std::unique_ptr<ApkResourceContainer>> ApkResourceContainer::FromPath(
+    const std::string& path) {
+  auto zip_assets = ZipAssetsProvider::Create(path);
+  if (zip_assets == nullptr) {
+    return Error("failed to load zip assets");
+  }
+  return std::unique_ptr<ApkResourceContainer>(
+      new ApkResourceContainer(std::move(zip_assets), path));
+}
+
+Result<const ResState*> ApkResourceContainer::GetState() const {
+  if (auto state = std::get_if<ResState>(&state_); state != nullptr) {
+    return state;
+  }
+
+  auto state =
+      ResState::Initialize(std::move(std::get<std::unique_ptr<ZipAssetsProvider>>(state_)));
+  if (!state) {
+    return state.GetError();
+  }
+
+  state_ = std::move(*state);
+  return &std::get<ResState>(state_);
+}
+
+ZipAssetsProvider* ApkResourceContainer::GetZipAssets() const {
+  if (auto zip = std::get_if<std::unique_ptr<ZipAssetsProvider>>(&state_); zip != nullptr) {
+    return zip->get();
+  }
+  return std::get<ResState>(state_).zip_assets;
+}
+
+Result<bool> ApkResourceContainer::DefinesOverlayable() const {
+  auto state = GetState();
+  if (!state) {
+    return state.GetError();
+  }
+  return (*state)->package->DefinesOverlayable();
+}
+
+Result<const android::OverlayableInfo*> ApkResourceContainer::GetOverlayableInfo(
+    ResourceId id) const {
+  auto state = GetState();
+  if (!state) {
+    return state.GetError();
+  }
+  return (*state)->package->GetOverlayableInfo(id);
+}
+
+Result<OverlayManifestInfo> ApkResourceContainer::FindOverlayInfo(const std::string& name) const {
+  return ExtractOverlayManifestInfo(GetZipAssets(), name);
+}
+
+Result<OverlayData> ApkResourceContainer::GetOverlayData(const OverlayManifestInfo& info) const {
+  const auto state = GetState();
+  if (!state) {
+    return state.GetError();
+  }
+
+  if (info.resource_mapping != 0) {
+    return CreateResourceMapping(info.resource_mapping, GetZipAssets(), (*state)->am.get(),
+                                 (*state)->arsc, (*state)->package);
+  }
+  return CreateResourceMappingLegacy((*state)->am.get(), (*state)->package);
+}
+
+Result<uint32_t> ApkResourceContainer::GetCrc() const {
+  return CalculateCrc(GetZipAssets());
+}
+
+const std::string& ApkResourceContainer::GetPath() const {
+  return path_;
+}
+
+Result<ResourceId> ApkResourceContainer::GetResourceId(const std::string& name) const {
+  auto state = GetState();
+  if (!state) {
+    return state.GetError();
+  }
+  auto id = (*state)->am->GetResourceId(name, "", (*state)->package->GetPackageName());
+  if (!id.has_value()) {
+    return Error("failed to find resource '%s'", name.c_str());
+  }
+
+  // Retrieve the compile-time resource id of the target resource.
+  return REWRITE_PACKAGE(*id, (*state)->package->GetPackageId());
+}
+
+Result<std::string> ApkResourceContainer::GetResourceName(ResourceId id) const {
+  auto state = GetState();
+  if (!state) {
+    return state.GetError();
+  }
+  return utils::ResToTypeEntryName(*(*state)->am, id);
+}
+
+Result<std::unique_ptr<TargetResourceContainer>> TargetResourceContainer::FromPath(
+    std::string path) {
+  auto result = ApkResourceContainer::FromPath(path);
+  if (!result) {
+    return result.GetError();
+  }
+  return std::unique_ptr<TargetResourceContainer>(result->release());
+}
+
+Result<std::unique_ptr<OverlayResourceContainer>> OverlayResourceContainer::FromPath(
+    std::string path) {
+  // Load the path as a fabricated overlay if the file magic indicates this is a fabricated overlay.
+  if (android::IsFabricatedOverlay(path)) {
+    auto result = FabricatedOverlayContainer::FromPath(path);
+    if (!result) {
+      return result.GetError();
+    }
+    return std::unique_ptr<OverlayResourceContainer>(result->release());
+  }
+
+  // Fallback to loading the container as an APK.
+  auto result = ApkResourceContainer::FromPath(path);
+  if (!result) {
+    return result.GetError();
+  }
+  return std::unique_ptr<OverlayResourceContainer>(result->release());
+}
+
+}  // namespace android::idmap2
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