Add fabricated RRO generation to libidmap2

Fabricated Runtime Resource Overlays are overlays that are generated
at runtime and are stored in the data/ partition.

The system can fabricate RROs at runtime to dynamically theme the
device. Idmaps can now be created from APK RROs and fabricated RROs.

Rather than operating on ApkAssets, libidmap2 now operates on abstract
resource "containers" that supply resource values. Target resource
containers implement methods needed to query overlayable and target
overlay information. Currently only APKs can be loaded as target
resource containers. Overlay resource containers implement methods to
supply the mapping of target resource to overlay value and other
overlay information.

The format of a fabricated RRO is as follows:
0x00 - 0x04 : fabricated overlay magic (always FRRO)
0x04 - 0x08 : file format version
0x08 - 0x0c : crc of version + proto data
0x0c - EOF  : proto fabricated overlay data

The magic is used to quickly detect if the file is a fabricated overlay.
The version is incremented whenever backwards incompatible changes are
made to the proto file format. Idmap must always be able to upgrade
fabricated overlays from previous versions to new versions, so all
previous versions must be checked into the tree.

Bug: 172471315
Test: libidmap2_tests && libandroidfw_tests
Change-Id: I4c9f29da278672e5695fb57d131a44c11a835180

1 files changed, 65 insertions, 67 deletions

diff --git a/cmds/idmap2/idmap2d/Idmap2Service.cpp b/cmds/idmap2/idmap2d/Idmap2Service.cpp
index 93537d32299b..f62630e702d4 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.cpp
+++ b/cmds/idmap2/idmap2d/Idmap2Service.cpp
@@ -35,17 +35,16 @@
 #include "idmap2/Idmap.h"
 #include "idmap2/Result.h"
 #include "idmap2/SysTrace.h"
-#include "idmap2/ZipFile.h"
 #include "utils/String8.h"
 
 using android::IPCThreadState;
 using android::base::StringPrintf;
 using android::binder::Status;
 using android::idmap2::BinaryStreamVisitor;
-using android::idmap2::GetPackageCrc;
 using android::idmap2::Idmap;
 using android::idmap2::IdmapHeader;
-using android::idmap2::ZipFile;
+using android::idmap2::OverlayResourceContainer;
+using android::idmap2::TargetResourceContainer;
 using android::idmap2::utils::kIdmapCacheDir;
 using android::idmap2::utils::kIdmapFilePermissionMask;
 using android::idmap2::utils::UidHasWriteAccessToPath;
@@ -68,40 +67,24 @@ Status error(const std::string& msg) {
 PolicyBitmask ConvertAidlArgToPolicyBitmask(int32_t arg) {
   return static_cast<PolicyBitmask>(arg);
 }
-
-Status GetCrc(const std::string& apk_path, uint32_t* out_crc) {
-  const auto zip = ZipFile::Open(apk_path);
-  if (!zip) {
-    return error(StringPrintf("failed to open apk %s", apk_path.c_str()));
-  }
-
-  const auto crc = GetPackageCrc(*zip);
-  if (!crc) {
-    return error(crc.GetErrorMessage());
-  }
-
-  *out_crc = *crc;
-  return ok();
-}
-
 }  // namespace
 
 namespace android::os {
 
-Status Idmap2Service::getIdmapPath(const std::string& overlay_apk_path,
+Status Idmap2Service::getIdmapPath(const std::string& overlay_path,
                                    int32_t user_id ATTRIBUTE_UNUSED, std::string* _aidl_return) {
   assert(_aidl_return);
-  SYSTRACE << "Idmap2Service::getIdmapPath " << overlay_apk_path;
-  *_aidl_return = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
+  SYSTRACE << "Idmap2Service::getIdmapPath " << overlay_path;
+  *_aidl_return = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_path);
   return ok();
 }
 
-Status Idmap2Service::removeIdmap(const std::string& overlay_apk_path,
-                                  int32_t user_id ATTRIBUTE_UNUSED, bool* _aidl_return) {
+Status Idmap2Service::removeIdmap(const std::string& overlay_path, int32_t user_id ATTRIBUTE_UNUSED,
+                                  bool* _aidl_return) {
   assert(_aidl_return);
-  SYSTRACE << "Idmap2Service::removeIdmap " << overlay_apk_path;
+  SYSTRACE << "Idmap2Service::removeIdmap " << overlay_path;
   const uid_t uid = IPCThreadState::self()->getCallingUid();
-  const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
+  const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_path);
   if (!UidHasWriteAccessToPath(uid, idmap_path)) {
     *_aidl_return = false;
     return error(base::StringPrintf("failed to unlink %s: calling uid %d lacks write access",
@@ -115,85 +98,79 @@ Status Idmap2Service::removeIdmap(const std::string& overlay_apk_path,
   return ok();
 }
 
-Status Idmap2Service::verifyIdmap(const std::string& target_apk_path,
-                                  const std::string& overlay_apk_path, int32_t fulfilled_policies,
-                                  bool enforce_overlayable, int32_t user_id ATTRIBUTE_UNUSED,
-                                  bool* _aidl_return) {
-  SYSTRACE << "Idmap2Service::verifyIdmap " << overlay_apk_path;
+Status Idmap2Service::verifyIdmap(const std::string& target_path, const std::string& overlay_path,
+                                  int32_t fulfilled_policies, bool enforce_overlayable,
+                                  int32_t user_id ATTRIBUTE_UNUSED, bool* _aidl_return) {
+  SYSTRACE << "Idmap2Service::verifyIdmap " << overlay_path;
   assert(_aidl_return);
 
-  const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
+  const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_path);
   std::ifstream fin(idmap_path);
   const std::unique_ptr<const IdmapHeader> header = IdmapHeader::FromBinaryStream(fin);
   fin.close();
   if (!header) {
     *_aidl_return = false;
-    return error("failed to parse idmap header");
+    LOG(WARNING) << "failed to parse idmap header of '" << idmap_path << "'";
+    return ok();
   }
 
-  uint32_t target_crc;
-  if (target_apk_path == kFrameworkPath && android_crc_) {
-    target_crc = *android_crc_;
-  } else {
-    auto target_crc_status = GetCrc(target_apk_path, &target_crc);
-    if (!target_crc_status.isOk()) {
-      *_aidl_return = false;
-      return target_crc_status;
-    }
-
-    // Loading the framework zip can take several milliseconds. Cache the crc of the framework
-    // resource APK to reduce repeated work during boot.
-    if (target_apk_path == kFrameworkPath) {
-      android_crc_ = target_crc;
-    }
+  const auto target = GetTargetContainer(target_path);
+  if (!target) {
+    *_aidl_return = false;
+    LOG(WARNING) << "failed to load target '" << target_path << "'";
+    return ok();
   }
 
-  uint32_t overlay_crc;
-  auto overlay_crc_status = GetCrc(overlay_apk_path, &overlay_crc);
-  if (!overlay_crc_status.isOk()) {
+  const auto overlay = OverlayResourceContainer::FromPath(overlay_path);
+  if (!overlay) {
     *_aidl_return = false;
-    return overlay_crc_status;
+    LOG(WARNING) << "failed to load overlay '" << overlay_path << "'";
+    return ok();
   }
 
   // TODO(162841629): Support passing overlay name to idmap2d verify
   auto up_to_date =
-      header->IsUpToDate(target_apk_path, overlay_apk_path, "", target_crc, overlay_crc,
+      header->IsUpToDate(*GetPointer(*target), **overlay, "",
                          ConvertAidlArgToPolicyBitmask(fulfilled_policies), enforce_overlayable);
 
   *_aidl_return = static_cast<bool>(up_to_date);
-  return *_aidl_return ? ok() : error(up_to_date.GetErrorMessage());
+  if (!up_to_date) {
+    LOG(WARNING) << "idmap '" << idmap_path
+                 << "' not up to date : " << up_to_date.GetErrorMessage();
+  }
+  return ok();
 }
 
-Status Idmap2Service::createIdmap(const std::string& target_apk_path,
-                                  const std::string& overlay_apk_path, int32_t fulfilled_policies,
-                                  bool enforce_overlayable, int32_t user_id ATTRIBUTE_UNUSED,
+Status Idmap2Service::createIdmap(const std::string& target_path, const std::string& overlay_path,
+                                  int32_t fulfilled_policies, bool enforce_overlayable,
+                                  int32_t user_id ATTRIBUTE_UNUSED,
                                   std::optional<std::string>* _aidl_return) {
   assert(_aidl_return);
-  SYSTRACE << "Idmap2Service::createIdmap " << target_apk_path << " " << overlay_apk_path;
+  SYSTRACE << "Idmap2Service::createIdmap " << target_path << " " << overlay_path;
   _aidl_return->reset();
 
   const PolicyBitmask policy_bitmask = ConvertAidlArgToPolicyBitmask(fulfilled_policies);
 
-  const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
+  const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_path);
   const uid_t uid = IPCThreadState::self()->getCallingUid();
   if (!UidHasWriteAccessToPath(uid, idmap_path)) {
     return error(base::StringPrintf("will not write to %s: calling uid %d lacks write accesss",
                                     idmap_path.c_str(), uid));
   }
 
-  const std::unique_ptr<const ApkAssets> target_apk = ApkAssets::Load(target_apk_path);
-  if (!target_apk) {
-    return error("failed to load apk " + target_apk_path);
+  const auto target = GetTargetContainer(target_path);
+  if (!target) {
+    return error("failed to load target '%s'" + target_path);
   }
 
-  const std::unique_ptr<const ApkAssets> overlay_apk = ApkAssets::Load(overlay_apk_path);
-  if (!overlay_apk) {
-    return error("failed to load apk " + overlay_apk_path);
+  const auto overlay = OverlayResourceContainer::FromPath(overlay_path);
+  if (!overlay) {
+    return error("failed to load apk overlay '%s'" + overlay_path);
   }
 
   // TODO(162841629): Support passing overlay name to idmap2d create
-  const auto idmap =
-      Idmap::FromApkAssets(*target_apk, *overlay_apk, "", policy_bitmask, enforce_overlayable);
+  const auto idmap = Idmap::FromContainers(*GetPointer(*target), **overlay, "", policy_bitmask,
+                                           enforce_overlayable);
   if (!idmap) {
     return error(idmap.GetErrorMessage());
   }
@@ -220,4 +197,25 @@ Status Idmap2Service::createIdmap(const std::string& target_apk_path,
   return ok();
 }
 
+idmap2::Result<Idmap2Service::TargetResourceContainerPtr> Idmap2Service::GetTargetContainer(
+    const std::string& target_path) {
+  if (target_path == kFrameworkPath) {
+    if (framework_apk_cache_ == nullptr) {
+      // Initialize the framework APK cache.
+      auto target = TargetResourceContainer::FromPath(target_path);
+      if (!target) {
+        return target.GetError();
+      }
+      framework_apk_cache_ = std::move(*target);
+    }
+    return {framework_apk_cache_.get()};
+  }
+
+  auto target = TargetResourceContainer::FromPath(target_path);
+  if (!target) {
+    return target.GetError();
+  }
+  return {std::move(*target)};
+}
+
 }  // namespace android::os