Locate and mount image within an APEX package.
Test: on device, and also unit tests
Bug: 112455435
Change-Id: Ia111d37c391b06bbf1ddbeb0474a303e427bb581
diff --git a/apexd/apex_file.cpp b/apexd/apex_file.cpp
new file mode 100644
index 0000000..2be4d26
--- /dev/null
+++ b/apexd/apex_file.cpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2018 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 <android-base/logging.h>
+#include <ziparchive/zip_archive.h>
+#include <memory>
+#include <string>
+
+#include "apex_file.h"
+
+namespace android {
+namespace apex {
+
+std::unique_ptr<ApexFile> ApexFile::Open(const std::string& apex_filename) {
+ std::unique_ptr<ApexFile> ret(new ApexFile(apex_filename));
+ if (ret->OpenInternal() < 0) {
+ return nullptr;
+ }
+ return ret;
+}
+
+ApexFile::~ApexFile() {
+ if (handle_ != nullptr) {
+ CloseArchive(handle_);
+ }
+}
+
+static constexpr const char* kImageFilename = "image.img";
+
+int ApexFile::OpenInternal() {
+ if (handle_ != nullptr) {
+ // Already opened.
+ return 0;
+ }
+ int ret = OpenArchive(apex_filename_.c_str(), &handle_);
+ if (ret < 0) {
+ LOG(ERROR) << "Failed to open package " << apex_filename_ << ": "
+ << ErrorCodeString(ret);
+ return ret;
+ }
+
+ // Locate the mountable image within the zipfile and store offset and size.
+ ZipEntry entry;
+ ret = FindEntry(handle_, ZipString(kImageFilename), &entry);
+ if (ret < 0) {
+ LOG(ERROR) << "Could not find entry \"" << kImageFilename
+ << "\" in package " << apex_filename_ << ": "
+ << ErrorCodeString(ret);
+ return ret;
+ }
+ image_offset_ = entry.offset;
+ image_size_ = entry.uncompressed_length;
+ return 0;
+}
+
+} // namespace apex
+} // namespace android
