payload_generation_config.h revision 14158570d3995008dc93a628004118b87a6bca01 
1// Copyright 2015 The Chromium OS Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
6#define UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
7
8#include <cstddef>
9
10#include <string>
11#include <vector>
12
13#include "update_engine/update_metadata.pb.h"
14
15namespace chromeos_update_engine {
16
17// The list different kind of partitions supported by the updater.
18enum class PartitionName {
19  kKernel,
20  kRootfs,
21};
22
23struct PartitionConfig {
24  explicit PartitionConfig(PartitionName name) : name(name) {}
25
26  // Returns whether the PartitionConfig is not an empty image and all the
27  // fields are set correctly to a valid image file.
28  bool ValidateExists() const;
29
30  // The path to the partition file. This can be a regular file or a block
31  // device such as a loop device.
32  std::string path;
33
34  // The size of the data in |path|. If rootfs verification is used (verity)
35  // this value should match the size of the verity device for the rootfs, and
36  // the size of the whole kernel. This value could be smaller than the
37  // partition and is the size of the data update_engine assumes verified for
38  // the source image, and the size of that data it should generate for the
39  // target image.
40  uint64_t size = 0;
41
42  PartitionName name;
43};
44
45// The ImageConfig struct describes a pair of binaries kernel and rootfs and the
46// metadata associated with the image they are part of, like build number, size,
47// etc.
48struct ImageConfig {
49  // Returns whether the ImageConfig is an empty image.
50  bool ValidateIsEmpty() const;
51
52  // Load |rootfs_size| and |kernel.size| from the respective image files. For
53  // the kernel, the whole |kernel.path| file is assumed. For the rootfs, the
54  // size is detected from the filesystem.
55  // Returns whether the image size was properly detected.
56  bool LoadImageSize();
57
58  // Load the |rootfs_size| stored in the kernel command line in the
59  // |kernel.path| when the kernel is using rootfs verification (dm-verity).
60  // Returns whether it loaded the size from the kernel command line. For
61  // example, it would return false if no |kernel.path| was provided or the
62  // kernel doesn't have verity enabled.
63  bool LoadVerityRootfsSize();
64
65  // Returns whether the |image_info| field is empty.
66  bool ImageInfoIsEmpty() const;
67
68  // The ImageInfo message defined in the update_metadata.proto file describes
69  // the metadata of the image.
70  ImageInfo image_info;
71
72  // The updated partitions.
73  PartitionConfig rootfs = PartitionConfig{PartitionName::kRootfs};
74  PartitionConfig kernel = PartitionConfig{PartitionName::kKernel};
75};
76
77// The PayloadGenerationConfig struct encapsulates all the configuration to
78// build the requested payload. This includes information about the old and new
79// image as well as the restrictions applied to the payload (like minor-version
80// and full/delta payload).
81struct PayloadGenerationConfig {
82  // Returns whether the PayloadGenerationConfig is valid.
83  bool Validate() const;
84
85  // Image information about the new image that's the target of this payload.
86  ImageConfig target;
87
88  // Image information pertaining the old image, if any. This is only valid
89  // if is_full is false, so we are requested a delta payload.
90  ImageConfig source;
91
92  // Wheter the requested payload is a delta payload.
93  bool is_delta = false;
94
95  // The minor_version of the requested payload.
96  uint32_t minor_version;
97
98  // The size of the rootfs partition, that not necessarily is the same as the
99  // filesystem in either source or target version, since there is some space
100  // after the partition used to store the verity hashes and or the bootcache.
101  uint64_t rootfs_partition_size = 0;
102
103  // The chunk size is the maximum size that a single operation should write in
104  // the destination. Operations bigger than chunk_size should be split. A value
105  // of -1 means no chunk_size limit.
106  off_t chunk_size = -1;
107
108  // TODO(deymo): Remove the block_size member and maybe replace it with a
109  // minimum alignment size for blocks (if needed). Algorithms should be able to
110  // pick the block_size they want, but for now only 4 KiB is supported.
111
112  // The block size used for all the operations in the manifest.
113  size_t block_size = 4096;
114};
115
116}  // namespace chromeos_update_engine
117
118#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
119