Add decompression capability to apexd for compressed APEX
Apexd can now decompress a compressed APEX. We still haven't integrated
this new ability with the boot flow yet. It will be done in next CL.
Bug: 172911820
Test: atest ApexFileTest#Decompress
Test: atest ApexFileTest#DecompressWithoutProperSuffix
Change-Id: If8e6f7de86cbefecdb1e1ed955b39fc3f58521e2
diff --git a/apexd/apex_file.cpp b/apexd/apex_file.cpp
index d40e367..6169ad5 100644
--- a/apexd/apex_file.cpp
+++ b/apexd/apex_file.cpp
@@ -386,5 +386,55 @@
return verity_data;
}
+Result<void> ApexFile::Decompress(const std::string& dest_path) const {
+ const std::string& src_path = GetPath();
+
+ // We should decompress compressed APEX files only
+ if (!IsCompressed()) {
+ return ErrnoError() << "Cannot decompress an uncompressed APEX";
+ }
+
+ // Get file descriptor of the compressed apex file
+ unique_fd src_fd(open(src_path.c_str(), O_RDONLY | O_CLOEXEC));
+ if (src_fd.get() == -1) {
+ return ErrnoError() << "Failed to open compressed APEX " << GetPath();
+ }
+
+ // Open it as a zip file
+ ZipArchiveHandle handle;
+ int ret = OpenArchiveFd(src_fd.get(), src_path.c_str(), &handle, false);
+ if (ret < 0) {
+ return Error() << "Failed to open package " << src_path << ": "
+ << ErrorCodeString(ret);
+ }
+ auto handle_guard =
+ android::base::make_scope_guard([&handle] { CloseArchive(handle); });
+
+ // Find the original apex file inside the zip and extract to dest
+ ZipEntry entry;
+ ret = FindEntry(handle, kCompressedApexFilename, &entry);
+ if (ret < 0) {
+ return Error() << "Could not find entry \"" << kCompressedApexFilename
+ << "\" in package " << src_path << ": "
+ << ErrorCodeString(ret);
+ }
+
+ // Open destination file descriptor
+ unique_fd dest_fd(
+ open(dest_path.c_str(), O_WRONLY | O_CLOEXEC | O_CREAT, 0644));
+ if (dest_fd.get() == -1) {
+ return ErrnoError() << "Failed to open decompression destination "
+ << GetPath();
+ }
+ ret = ExtractEntryToFile(handle, &entry, dest_fd.get());
+ if (ret < 0) {
+ return Error() << "Could not decompress to file " << dest_path
+ << ErrorCodeString(ret);
+ }
+
+ LOG(VERBOSE) << "Decompressed " << src_path << " to " << dest_path;
+ return {};
+}
+
} // namespace apex
} // namespace android
