1 files changed, 70 insertions, 11 deletions

diff --git a/cmds/idmap2/idmap2d/Idmap2Service.cpp b/cmds/idmap2/idmap2d/Idmap2Service.cpp
index d7237763a2e5..15e22a3410cf 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.cpp
+++ b/cmds/idmap2/idmap2d/Idmap2Service.cpp
@@ -33,22 +33,29 @@
 #include "idmap2/BinaryStreamVisitor.h"
 #include "idmap2/FileUtils.h"
 #include "idmap2/Idmap.h"
-#include "idmap2/Policies.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::PolicyBitmask;
+using android::idmap2::ZipFile;
 using android::idmap2::utils::kIdmapCacheDir;
 using android::idmap2::utils::kIdmapFilePermissionMask;
 using android::idmap2::utils::UidHasWriteAccessToPath;
 
+using PolicyBitmask = android::ResTable_overlayable_policy_header::PolicyBitmask;
+
 namespace {
 
+constexpr const char* kFrameworkPath = "/system/framework/framework-res.apk";
+
 Status ok() {
   return Status::ok();
 }
@@ -62,6 +69,21 @@ 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 {
@@ -93,21 +115,52 @@ Status Idmap2Service::removeIdmap(const std::string& overlay_apk_path,
   return ok();
 }
 
-Status Idmap2Service::verifyIdmap(const std::string& overlay_apk_path,
-                                  int32_t fulfilled_policies ATTRIBUTE_UNUSED,
-                                  bool enforce_overlayable ATTRIBUTE_UNUSED,
-                                  int32_t user_id ATTRIBUTE_UNUSED, bool* _aidl_return) {
+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;
   assert(_aidl_return);
+
   const std::string idmap_path = Idmap::CanonicalIdmapPathFor(kIdmapCacheDir, overlay_apk_path);
   std::ifstream fin(idmap_path);
   const std::unique_ptr<const IdmapHeader> header = IdmapHeader::FromBinaryStream(fin);
   fin.close();
-  *_aidl_return = header && header->IsUpToDate();
+  if (!header) {
+    *_aidl_return = false;
+    return error("failed to parse idmap header");
+  }
 
-  // TODO(b/119328308): Check that the set of fulfilled policies of the overlay has not changed
+  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;
+    }
+  }
 
-  return ok();
+  uint32_t overlay_crc;
+  auto overlay_crc_status = GetCrc(overlay_apk_path, &overlay_crc);
+  if (!overlay_crc_status.isOk()) {
+    *_aidl_return = false;
+    return overlay_crc_status;
+  }
+
+  auto up_to_date =
+      header->IsUpToDate(target_apk_path.c_str(), overlay_apk_path.c_str(), target_crc, overlay_crc,
+                         ConvertAidlArgToPolicyBitmask(fulfilled_policies), enforce_overlayable);
+
+  *_aidl_return = static_cast<bool>(up_to_date);
+  return *_aidl_return ? ok() : error(up_to_date.GetErrorMessage());
 }
 
 Status Idmap2Service::createIdmap(const std::string& target_apk_path,
@@ -137,21 +190,27 @@ Status Idmap2Service::createIdmap(const std::string& target_apk_path,
     return error("failed to load apk " + overlay_apk_path);
   }
 
-  const auto idmap = Idmap::FromApkAssets(target_apk_path, *target_apk, overlay_apk_path,
-                                          *overlay_apk, policy_bitmask, enforce_overlayable);
+  const auto idmap =
+      Idmap::FromApkAssets(*target_apk, *overlay_apk, policy_bitmask, enforce_overlayable);
   if (!idmap) {
     return error(idmap.GetErrorMessage());
   }
 
+  // idmap files are mapped with mmap in libandroidfw. Deleting and recreating the idmap guarantees
+  // that existing memory maps will continue to be valid and unaffected.
+  unlink(idmap_path.c_str());
+
   umask(kIdmapFilePermissionMask);
   std::ofstream fout(idmap_path);
   if (fout.fail()) {
     return error("failed to open idmap path " + idmap_path);
   }
+
   BinaryStreamVisitor visitor(fout);
   (*idmap)->accept(&visitor);
   fout.close();
   if (fout.fail()) {
+    unlink(idmap_path.c_str());
     return error("failed to write to idmap path " + idmap_path);
   }