| // Copyright 2021 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <lib/zbitl/view.h> |
| |
| namespace zbitl { |
| |
| using namespace std::literals; |
| |
| fitx::result<std::string_view> CheckItemHeader(const zbi_header_t& header) { |
| // Strict mode also checks policy requirements. Boot loaders do not always |
| // bother with setting the fields correctly, but the kernel need not care. |
| if (header.magic != ZBI_ITEM_MAGIC) { |
| return fitx::error{"bad item magic number"sv}; |
| } |
| if (!(header.flags & ZBI_FLAG_VERSION)) { |
| return fitx::error{"bad item header version"sv}; |
| } |
| if (!(header.flags & ZBI_FLAG_CRC32) && header.crc32 != ZBI_ITEM_NO_CRC32) { |
| return fitx::error{"bad crc32 field in item without CRC"sv}; |
| } |
| |
| return fitx::ok(); |
| } |
| |
| fitx::result<std::string_view> CheckContainerHeader(const zbi_header_t& header) { |
| if (auto result = CheckItemHeader(header); result.is_error()) { |
| return result.take_error(); |
| } |
| if (header.type != ZBI_TYPE_CONTAINER) { |
| return fitx::error("bad container type"sv); |
| } |
| if (header.extra != ZBI_CONTAINER_MAGIC) { |
| return fitx::error("bad container magic"sv); |
| } |
| if (header.flags & ZBI_FLAG_CRC32) { |
| return fitx::error("container header has CRC32 flag"sv); |
| } |
| if (header.length % ZBI_ALIGNMENT != 0) { |
| return fitx::error("container header has misaligned length"sv); |
| } |
| return fitx::ok(); |
| } |
| |
| } // namespace zbitl |
