payload_generation_config.h revision 2d3b2d635e50c6886e285afb86c3187d9e0bd360 
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 <memory>
11#include <string>
12#include <vector>
13
14#include "update_engine/payload_generator/filesystem_interface.h"
15#include "update_engine/update_metadata.pb.h"
16
17namespace chromeos_update_engine {
18
19// The list different kind of partitions supported by the updater.
20enum class PartitionName {
21  kKernel,
22  kRootfs,
23};
24
25// Return a string name for the PartitionName.
26std::string PartitionNameString(PartitionName name);
27
28struct PartitionConfig {
29  explicit PartitionConfig(PartitionName name) : name(name) {}
30
31  // Returns whether the PartitionConfig is not an empty image and all the
32  // fields are set correctly to a valid image file.
33  bool ValidateExists() const;
34
35  // Open then filesystem stored in this partition and stores it in
36  // |fs_interface|. Returns whether opening the filesystem worked.
37  bool OpenFilesystem();
38
39  // The path to the partition file. This can be a regular file or a block
40  // device such as a loop device.
41  std::string path;
42
43  // The size of the data in |path|. If rootfs verification is used (verity)
44  // this value should match the size of the verity device for the rootfs, and
45  // the size of the whole kernel. This value could be smaller than the
46  // partition and is the size of the data update_engine assumes verified for
47  // the source image, and the size of that data it should generate for the
48  // target image.
49  uint64_t size = 0;
50
51  // The FilesystemInterface implementation used to access this partition's
52  // files.
53  std::unique_ptr<FilesystemInterface> fs_interface;
54
55  PartitionName name;
56};
57
58// The ImageConfig struct describes a pair of binaries kernel and rootfs and the
59// metadata associated with the image they are part of, like build number, size,
60// etc.
61struct ImageConfig {
62  // Returns whether the ImageConfig is an empty image.
63  bool ValidateIsEmpty() const;
64
65  // Load |rootfs_size| and |kernel.size| from the respective image files. For
66  // the kernel, the whole |kernel.path| file is assumed. For the rootfs, the
67  // size is detected from the filesystem.
68  // Returns whether the image size was properly detected.
69  bool LoadImageSize();
70
71  // Load the |rootfs_size| stored in the kernel command line in the
72  // |kernel.path| when the kernel is using rootfs verification (dm-verity).
73  // Returns whether it loaded the size from the kernel command line. For
74  // example, it would return false if no |kernel.path| was provided or the
75  // kernel doesn't have verity enabled.
76  bool LoadVerityRootfsSize();
77
78  // Returns whether the |image_info| field is empty.
79  bool ImageInfoIsEmpty() const;
80
81  // The ImageInfo message defined in the update_metadata.proto file describes
82  // the metadata of the image.
83  ImageInfo image_info;
84
85  // The updated partitions.
86  PartitionConfig rootfs = PartitionConfig{PartitionName::kRootfs};
87  PartitionConfig kernel = PartitionConfig{PartitionName::kKernel};
88};
89
90// The PayloadGenerationConfig struct encapsulates all the configuration to
91// build the requested payload. This includes information about the old and new
92// image as well as the restrictions applied to the payload (like minor-version
93// and full/delta payload).
94struct PayloadGenerationConfig {
95  // Returns whether the PayloadGenerationConfig is valid.
96  bool Validate() const;
97
98  // Image information about the new image that's the target of this payload.
99  ImageConfig target;
100
101  // Image information pertaining the old image, if any. This is only valid
102  // if is_full is false, so we are requested a delta payload.
103  ImageConfig source;
104
105  // Wheter the requested payload is a delta payload.
106  bool is_delta = false;
107
108  // The minor_version of the requested payload.
109  uint32_t minor_version;
110
111  // The size of the rootfs partition, that not necessarily is the same as the
112  // filesystem in either source or target version, since there is some space
113  // after the partition used to store the verity hashes and or the bootcache.
114  uint64_t rootfs_partition_size = 0;
115
116  // The |hard_chunk_size| is the maximum size that a single operation should
117  // write in the destination. Operations bigger than chunk_size should be
118  // split. A value of -1 means no hard chunk size limit. A very low limit
119  // means more operations, and less of a chance to reuse the data.
120  ssize_t hard_chunk_size = -1;
121
122  // The |soft_chunk_size| is the preferred chunk size to use when there's no
123  // significant impact to the operations. For example, REPLACE, MOVE and
124  // SOURCE_COPY operations are not significantly impacted by the chunk size,
125  // except for a few bytes overhead in the manifest to describe extra
126  // operations. On the other hand, splitting BSDIFF operations impacts the
127  // payload size since it is not possible to use the redundancy *between*
128  // chunks.
129  size_t soft_chunk_size = 2 * 1024 * 1024;
130
131  // TODO(deymo): Remove the block_size member and maybe replace it with a
132  // minimum alignment size for blocks (if needed). Algorithms should be able to
133  // pick the block_size they want, but for now only 4 KiB is supported.
134
135  // The block size used for all the operations in the manifest.
136  size_t block_size = 4096;
137};
138
139}  // namespace chromeos_update_engine
140
141#endif  // UPDATE_ENGINE_PAYLOAD_GENERATOR_PAYLOAD_GENERATION_CONFIG_H_
142