| /* | |
| * 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 "idmap2/ResourceMapping.h" | |
| #include <map> | |
| #include <memory> | |
| #include <set> | |
| #include <string> | |
| #include <utility> | |
| #include <vector> | |
| #include "android-base/stringprintf.h" | |
| #include "androidfw/ResourceTypes.h" | |
| #include "idmap2/PolicyUtils.h" | |
| #include "idmap2/ResourceUtils.h" | |
| using android::base::StringPrintf; | |
| using android::idmap2::utils::BitmaskToPolicies; | |
| using PolicyBitmask = android::ResTable_overlayable_policy_header::PolicyBitmask; | |
| using PolicyFlags = android::ResTable_overlayable_policy_header::PolicyFlags; | |
| namespace android::idmap2 { | |
| namespace { | |
| std::string ConcatPolicies(const std::vector<std::string>& policies) { | |
| std::string message; | |
| for (const std::string& policy : policies) { | |
| if (!message.empty()) { | |
| message.append("|"); | |
| } | |
| message.append(policy); | |
| } | |
| return message; | |
| } | |
| Result<Unit> CheckOverlayable(const TargetResourceContainer& target, | |
| const OverlayManifestInfo& overlay_info, | |
| const PolicyBitmask& fulfilled_policies, | |
| const ResourceId& target_resource) { | |
| constexpr const PolicyBitmask kDefaultPolicies = | |
| PolicyFlags::ODM_PARTITION | PolicyFlags::OEM_PARTITION | PolicyFlags::SYSTEM_PARTITION | | |
| PolicyFlags::VENDOR_PARTITION | PolicyFlags::PRODUCT_PARTITION | PolicyFlags::SIGNATURE | | |
| PolicyFlags::CONFIG_SIGNATURE; | |
| // If the resource does not have an overlayable definition, allow the resource to be overlaid if | |
| // the overlay is preinstalled, signed with the same signature as the target or signed with the | |
| // same signature as reference package defined in SystemConfig under 'overlay-config-signature' | |
| // tag. | |
| const Result<bool> defines_overlayable = target.DefinesOverlayable(); | |
| if (!defines_overlayable) { | |
| return Error(defines_overlayable.GetError(), "unable to retrieve overlayable info"); | |
| } | |
| if (!*defines_overlayable) { | |
| return (kDefaultPolicies & fulfilled_policies) != 0 | |
| ? Result<Unit>({}) | |
| : Error( | |
| "overlay must be preinstalled, signed with the same signature as the target," | |
| " or signed with the same signature as the package referenced through" | |
| " <overlay-config-signature>."); | |
| } | |
| const auto overlayable_info = target.GetOverlayableInfo(target_resource); | |
| if (!overlayable_info) { | |
| return overlayable_info.GetError(); | |
| } | |
| if (*overlayable_info == nullptr) { | |
| // Do not allow non-overlayable resources to be overlaid. | |
| return Error("target 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(R"(<overlay> android:targetName "%s" does not match overlayable name "%s")", | |
| overlay_info.target_name.c_str(), (*overlayable_info)->name.data()); | |
| } | |
| // Enforce policy restrictions if the resource is declared as overlayable. | |
| if (((*overlayable_info)->policy_flags & fulfilled_policies) == 0) { | |
| return Error(R"(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>({}); | |
| } | |
| std::string GetDebugResourceName(const ResourceContainer& container, ResourceId resid) { | |
| auto name = container.GetResourceName(resid); | |
| if (name) { | |
| return *name; | |
| } | |
| return StringPrintf("0x%08x", resid); | |
| } | |
| } // namespace | |
| Result<ResourceMapping> ResourceMapping::FromContainers(const TargetResourceContainer& target, | |
| const OverlayResourceContainer& overlay, | |
| const OverlayManifestInfo& overlay_info, | |
| const PolicyBitmask& fulfilled_policies, | |
| bool enforce_overlayable, | |
| LogInfo& log_info) { | |
| auto overlay_data = overlay.GetOverlayData(overlay_info); | |
| if (!overlay_data) { | |
| return overlay_data.GetError(); | |
| } | |
| ResourceMapping mapping; | |
| for (const auto& overlay_pair : overlay_data->pairs) { | |
| const auto target_resid = target.GetResourceId(overlay_pair.resource_name); | |
| if (!target_resid) { | |
| log_info.Warning(LogMessage() << target_resid.GetErrorMessage()); | |
| continue; | |
| } | |
| if (enforce_overlayable) { | |
| // Filter out resources the overlay is not allowed to override. | |
| auto overlayable = CheckOverlayable(target, overlay_info, fulfilled_policies, *target_resid); | |
| if (!overlayable) { | |
| log_info.Warning(LogMessage() << "overlay '" << overlay.GetPath() | |
| << "' is not allowed to overlay resource '" | |
| << GetDebugResourceName(target, *target_resid) | |
| << "' in target: " << overlayable.GetErrorMessage()); | |
| continue; | |
| } | |
| } | |
| if (auto result = mapping.AddMapping(*target_resid, overlay_pair.value); !result) { | |
| return Error(result.GetError(), "failed to add mapping for '%s'", | |
| GetDebugResourceName(target, *target_resid).c_str()); | |
| } | |
| } | |
| auto& string_pool_data = overlay_data->string_pool_data; | |
| if (string_pool_data.has_value()) { | |
| mapping.string_pool_offset_ = string_pool_data->string_pool_offset; | |
| mapping.string_pool_data_ = std::move(string_pool_data->data); | |
| mapping.string_pool_data_length_ = string_pool_data->data_length; | |
| } | |
| return std::move(mapping); | |
| } | |
| Result<Unit> ResourceMapping::AddMapping( | |
| ResourceId target_resource, | |
| const std::variant<OverlayData::ResourceIdValue, TargetValueWithConfig>& value) { | |
| // TODO(141485591): Ensure that the overlay type is compatible with the target type. If the | |
| // runtime types are not compatible, it could cause runtime crashes when the resource is resolved. | |
| if (auto overlay_resource = std::get_if<OverlayData::ResourceIdValue>(&value)) { | |
| if (target_map_.find(target_resource) != target_map_.end()) { | |
| return Error(R"(target resource id "0x%08x" mapped to multiple values)", target_resource); | |
| } | |
| target_map_.insert(std::make_pair(target_resource, overlay_resource->overlay_id)); | |
| if (overlay_resource->rewrite_id) { | |
| // An overlay resource can override multiple target resources at once. Rewrite the overlay | |
| // resource as the first target resource it overrides. | |
| overlay_map_.insert(std::make_pair(overlay_resource->overlay_id, target_resource)); | |
| } | |
| } else { | |
| auto[iter, inserted] = target_map_.try_emplace(target_resource, ConfigMap()); | |
| auto& resource_value = iter->second; | |
| if (!inserted && std::holds_alternative<ResourceId>(resource_value)) { | |
| return Error(R"(target resource id "0x%08x" mapped to multiple values)", target_resource); | |
| } | |
| auto& config_map = std::get<ConfigMap>(resource_value); | |
| const auto& config_value = std::get<TargetValueWithConfig>(value); | |
| if (config_map.find(config_value.config) != config_map.end()) { | |
| return Error(R"(target resource id "0x%08x" mapped to multiple values with the same config)", | |
| target_resource); | |
| } | |
| config_map.insert(config_value.to_pair()); | |
| } | |
| return Unit{}; | |
| } | |
| } // namespace android::idmap2 |