Parse <overlay> and abstract resource mapping
This change introduces idmap parsing of <overlay> tags.
The <overlay> tag allows one to explicitly map resources in the target
to either a resource in the overlay or an inline attribute value.
Use the android:resourcesMap atttribute on the <overlay> tag in the
android manifest to specify a file to provide the resource mapping.
Bug: 135943783
Bug: 135051420
Test: idmap2_tests
Change-Id: I1740dcdc01849c43b1f2cb8c6645d666dbb05dba
diff --git a/cmds/idmap2/libidmap2/Idmap.cpp b/cmds/idmap2/libidmap2/Idmap.cpp
index 4649675..389ade5 100644
--- a/cmds/idmap2/libidmap2/Idmap.cpp
+++ b/cmds/idmap2/libidmap2/Idmap.cpp
@@ -30,6 +30,7 @@
#include "android-base/macros.h"
#include "android-base/stringprintf.h"
#include "androidfw/AssetManager2.h"
+#include "idmap2/ResourceMapping.h"
#include "idmap2/ResourceUtils.h"
#include "idmap2/Result.h"
#include "idmap2/SysTrace.h"
@@ -41,10 +42,6 @@
namespace {
-#define EXTRACT_TYPE(resid) ((0x00ff0000 & (resid)) >> 16)
-
-#define EXTRACT_ENTRY(resid) (0x0000ffff & (resid))
-
class MatchingResources {
public:
void Add(ResourceId target_resid, ResourceId overlay_resid) {
@@ -97,28 +94,6 @@
return true;
}
-ResourceId NameToResid(const AssetManager2& am, const std::string& name) {
- return am.GetResourceId(name);
-}
-
-// TODO(martenkongstad): scan for package name instead of assuming package at index 0
-//
-// 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;
- }
- int id = packages[0]->GetPackageId();
- return loaded_arsc.GetPackageById(id);
-}
-
Result<uint32_t> GetCrc(const ZipFile& zip) {
const Result<uint32_t> a = zip.Crc("resources.arsc");
const Result<uint32_t> b = zip.Crc("AndroidManifest.xml");
@@ -266,95 +241,57 @@
return {std::move(idmap)};
}
-std::string ConcatPolicies(const std::vector<std::string>& policies) {
- std::string message;
- for (const std::string& policy : policies) {
- if (!message.empty()) {
- message.append("|");
+Result<std::unique_ptr<const IdmapData>> IdmapData::FromResourceMapping(
+ const ResourceMapping& resource_mapping) {
+ if (resource_mapping.GetTargetToOverlayMap().empty()) {
+ return Error("no resources were overlaid");
+ }
+
+ MatchingResources matching_resources;
+ for (const auto mapping : resource_mapping.GetTargetToOverlayMap()) {
+ if (mapping.second.data_type != Res_value::TYPE_REFERENCE) {
+ // The idmap format must change to support non-references.
+ continue;
}
- message.append(policy);
+
+ matching_resources.Add(mapping.first, mapping.second.data_value);
}
- return message;
+ // encode idmap data
+ std::unique_ptr<IdmapData> data(new IdmapData());
+ const auto types_end = matching_resources.Map().cend();
+ for (auto ti = matching_resources.Map().cbegin(); ti != types_end; ++ti) {
+ auto ei = ti->second.cbegin();
+ std::unique_ptr<IdmapData::TypeEntry> type(new IdmapData::TypeEntry());
+ type->target_type_id_ = EXTRACT_TYPE(ei->first);
+ type->overlay_type_id_ = EXTRACT_TYPE(ei->second);
+ type->entry_offset_ = EXTRACT_ENTRY(ei->first);
+ EntryId last_target_entry = kNoEntry;
+ for (; ei != ti->second.cend(); ++ei) {
+ if (last_target_entry != kNoEntry) {
+ int count = EXTRACT_ENTRY(ei->first) - last_target_entry - 1;
+ type->entries_.insert(type->entries_.end(), count, kNoEntry);
+ }
+ type->entries_.push_back(EXTRACT_ENTRY(ei->second));
+ last_target_entry = EXTRACT_ENTRY(ei->first);
+ }
+ data->type_entries_.push_back(std::move(type));
+ }
+
+ std::unique_ptr<IdmapData::Header> data_header(new IdmapData::Header());
+ data_header->target_package_id_ = resource_mapping.GetTargetPackageId();
+ data_header->type_count_ = data->type_entries_.size();
+ data->header_ = std::move(data_header);
+ return {std::move(data)};
}
-Result<Unit> CheckOverlayable(const LoadedPackage& target_package,
- const utils::OverlayManifestInfo& overlay_info,
- const PolicyBitmask& fulfilled_policies, const ResourceId& resid) {
- static constexpr const PolicyBitmask sDefaultPolicies =
- PolicyFlags::POLICY_ODM_PARTITION | PolicyFlags::POLICY_OEM_PARTITION |
- PolicyFlags::POLICY_SYSTEM_PARTITION | PolicyFlags::POLICY_VENDOR_PARTITION |
- PolicyFlags::POLICY_PRODUCT_PARTITION | PolicyFlags::POLICY_SIGNATURE;
-
- // If the resource does not have an overlayable definition, allow the resource to be overlaid if
- // the overlay is preinstalled or signed with the same signature as the target.
- if (!target_package.DefinesOverlayable()) {
- return (sDefaultPolicies & fulfilled_policies) != 0
- ? Result<Unit>({})
- : Error(
- "overlay must be preinstalled or signed with the same signature as the "
- "target");
- }
-
- const OverlayableInfo* overlayable_info = target_package.GetOverlayableInfo(resid);
- if (overlayable_info == nullptr) {
- // Do not allow non-overlayable resources to be overlaid.
- return Error("resource has no overlayable declaration");
- }
-
- if (overlay_info.target_name != overlayable_info->name) {
- // If the overlay supplies a target overlayable name, the resource must belong to the
- // overlayable defined with the specified name to be overlaid.
- return Error("<overlay> android:targetName '%s' does not match overlayable name '%s'",
- overlay_info.target_name.c_str(), overlayable_info->name.c_str());
- }
-
- // Enforce policy restrictions if the resource is declared as overlayable.
- if ((overlayable_info->policy_flags & fulfilled_policies) == 0) {
- return Error("overlay with policies '%s' does not fulfill any overlayable policies '%s'",
- ConcatPolicies(BitmaskToPolicies(fulfilled_policies)).c_str(),
- ConcatPolicies(BitmaskToPolicies(overlayable_info->policy_flags)).c_str());
- }
-
- return Result<Unit>({});
-}
-
-Result<std::unique_ptr<const Idmap>> Idmap::FromApkAssets(const std::string& target_apk_path,
- const ApkAssets& target_apk_assets,
- const std::string& overlay_apk_path,
+Result<std::unique_ptr<const Idmap>> Idmap::FromApkAssets(const ApkAssets& target_apk_assets,
const ApkAssets& overlay_apk_assets,
const PolicyBitmask& fulfilled_policies,
bool enforce_overlayable) {
SYSTRACE << "Idmap::FromApkAssets";
- AssetManager2 target_asset_manager;
- if (!target_asset_manager.SetApkAssets({&target_apk_assets}, true, false)) {
- return Error("failed to create target asset manager");
- }
-
- AssetManager2 overlay_asset_manager;
- if (!overlay_asset_manager.SetApkAssets({&overlay_apk_assets}, true, false)) {
- return Error("failed to create overlay asset manager");
- }
-
- const LoadedArsc* target_arsc = target_apk_assets.GetLoadedArsc();
- if (target_arsc == nullptr) {
- return Error("failed to load target resources.arsc");
- }
-
- const LoadedArsc* overlay_arsc = overlay_apk_assets.GetLoadedArsc();
- if (overlay_arsc == nullptr) {
- return Error("failed to load overlay resources.arsc");
- }
-
- const LoadedPackage* target_pkg = GetPackageAtIndex0(*target_arsc);
- if (target_pkg == nullptr) {
- return Error("failed to load target package from resources.arsc");
- }
-
- const LoadedPackage* overlay_pkg = GetPackageAtIndex0(*overlay_arsc);
- if (overlay_pkg == nullptr) {
- return Error("failed to load overlay package from resources.arsc");
- }
+ const std::string& target_apk_path = target_apk_assets.GetPath();
+ const std::string& overlay_apk_path = overlay_apk_assets.GetPath();
const std::unique_ptr<const ZipFile> target_zip = ZipFile::Open(target_apk_path);
if (!target_zip) {
@@ -366,11 +303,6 @@
return Error("failed to open overlay as zip");
}
- auto overlay_info = utils::ExtractOverlayManifestInfo(overlay_apk_path);
- if (!overlay_info) {
- return overlay_info.GetError();
- }
-
std::unique_ptr<IdmapHeader> header(new IdmapHeader());
header->magic_ = kIdmapMagic;
header->version_ = kIdmapCurrentVersion;
@@ -395,7 +327,7 @@
memcpy(header->target_path_, target_apk_path.data(), target_apk_path.size());
if (overlay_apk_path.size() > sizeof(header->overlay_path_)) {
- return Error("overlay apk path \"%s\" longer than maximum size %zu", target_apk_path.c_str(),
+ return Error("overlay apk path \"%s\" longer than maximum size %zu", overlay_apk_path.c_str(),
sizeof(header->target_path_));
}
memset(header->overlay_path_, 0, sizeof(header->overlay_path_));
@@ -404,70 +336,24 @@
std::unique_ptr<Idmap> idmap(new Idmap());
idmap->header_ = std::move(header);
- // find the resources that exist in both packages
- MatchingResources matching_resources;
- const auto end = overlay_pkg->end();
- for (auto iter = overlay_pkg->begin(); iter != end; ++iter) {
- const ResourceId overlay_resid = *iter;
- Result<std::string> name = utils::ResToTypeEntryName(overlay_asset_manager, overlay_resid);
- if (!name) {
- continue;
- }
- // prepend "<package>:" to turn name into "<package>:<type>/<name>"
- const std::string full_name =
- base::StringPrintf("%s:%s", target_pkg->GetPackageName().c_str(), name->c_str());
- const ResourceId target_resid = NameToResid(target_asset_manager, full_name);
- if (target_resid == 0) {
- continue;
- }
-
- if (enforce_overlayable) {
- Result<Unit> success =
- CheckOverlayable(*target_pkg, *overlay_info, fulfilled_policies, target_resid);
- if (!success) {
- LOG(WARNING) << "overlay \"" << overlay_apk_path
- << "\" is not allowed to overlay resource \"" << full_name
- << "\": " << success.GetErrorMessage();
- continue;
- }
- }
-
- matching_resources.Add(target_resid, overlay_resid);
+ auto overlay_info = utils::ExtractOverlayManifestInfo(overlay_apk_path);
+ if (!overlay_info) {
+ return overlay_info.GetError();
}
- if (matching_resources.Map().empty()) {
- return Error("overlay \"%s\" does not successfully overlay any resource",
- overlay_apk_path.c_str());
+ auto resource_mapping =
+ ResourceMapping::FromApkAssets(target_apk_assets, overlay_apk_assets, *overlay_info,
+ fulfilled_policies, enforce_overlayable);
+ if (!resource_mapping) {
+ return resource_mapping.GetError();
}
- // encode idmap data
- std::unique_ptr<IdmapData> data(new IdmapData());
- const auto types_end = matching_resources.Map().cend();
- for (auto ti = matching_resources.Map().cbegin(); ti != types_end; ++ti) {
- auto ei = ti->second.cbegin();
- std::unique_ptr<IdmapData::TypeEntry> type(new IdmapData::TypeEntry());
- type->target_type_id_ = EXTRACT_TYPE(ei->first);
- type->overlay_type_id_ = EXTRACT_TYPE(ei->second);
- type->entry_offset_ = EXTRACT_ENTRY(ei->first);
- EntryId last_target_entry = kNoEntry;
- for (; ei != ti->second.cend(); ++ei) {
- if (last_target_entry != kNoEntry) {
- int count = EXTRACT_ENTRY(ei->first) - last_target_entry - 1;
- type->entries_.insert(type->entries_.end(), count, kNoEntry);
- }
- type->entries_.push_back(EXTRACT_ENTRY(ei->second));
- last_target_entry = EXTRACT_ENTRY(ei->first);
- }
- data->type_entries_.push_back(std::move(type));
+ auto idmap_data = IdmapData::FromResourceMapping(*resource_mapping);
+ if (!idmap_data) {
+ return idmap_data.GetError();
}
- std::unique_ptr<IdmapData::Header> data_header(new IdmapData::Header());
- data_header->target_package_id_ = target_pkg->GetPackageId();
- data_header->type_count_ = data->type_entries_.size();
- data->header_ = std::move(data_header);
-
- idmap->data_.push_back(std::move(data));
-
+ idmap->data_.push_back(std::move(*idmap_data));
return {std::move(idmap)};
}