1 files changed, 58 insertions, 0 deletions
diff --git a/app/services/bulk_imports/file_decompression_service.rb b/app/services/bulk_imports/file_decompression_service.rb
new file mode 100644
index 00000000000..fe9017377ec
--- /dev/null
+++ b/app/services/bulk_imports/file_decompression_service.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module BulkImports
+  class FileDecompressionService
+    include Gitlab::ImportExport::CommandLineUtil
+
+    ServiceError = Class.new(StandardError)
+
+    def initialize(dir:, filename:)
+      @dir = dir
+      @filename = filename
+      @filepath = File.join(@dir, @filename)
+      @decompressed_filename = File.basename(@filename, '.gz')
+      @decompressed_filepath = File.join(@dir, @decompressed_filename)
+    end
+
+    def execute
+      validate_dir
+      validate_decompressed_file_size if Feature.enabled?(:validate_import_decompressed_archive_size, default_enabled: :yaml)
+      validate_symlink(filepath)
+
+      decompress_file
+
+      validate_symlink(decompressed_filepath)
+
+      filepath
+    rescue StandardError => e
+      File.delete(filepath) if File.exist?(filepath)
+      File.delete(decompressed_filepath) if File.exist?(decompressed_filepath)
+
+      raise e
+    end
+
+    private
+
+    attr_reader :dir, :filename, :filepath, :decompressed_filename, :decompressed_filepath
+
+    def validate_dir
+      raise(ServiceError, 'Invalid target directory') unless dir.start_with?(Dir.tmpdir)
+    end
+
+    def validate_decompressed_file_size
+      raise(ServiceError, 'File decompression error') unless size_validator.valid?
+    end
+
+    def validate_symlink(filepath)
+      raise(ServiceError, 'Invalid file') if File.lstat(filepath).symlink?
+    end
+
+    def decompress_file
+      gunzip(dir: dir, filename: filename)
+    end
+
+    def size_validator
+      @size_validator ||= Gitlab::ImportExport::DecompressedArchiveSizeValidator.new(archive_path: filepath)
+    end
+  end
+end