1 //
2 // Copyright (C) 2021 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16
17 #include <fcntl.h>
18 #include <stdio.h>
19 #include <string.h>
20
21 #include <cstdint>
22 #include <cstdio>
23 #include <memory>
24
25 #include <sys/mman.h>
26 #include <sys/stat.h>
27
28 #include <base/files/file_path.h>
29 #include <libsnapshot/cow_writer.h>
30
31 #include "update_engine/common/cow_operation_convert.h"
32 #include "update_engine/common/utils.h"
33 #include "update_engine/payload_consumer/file_descriptor.h"
34 #include "update_engine/payload_consumer/payload_metadata.h"
35 #include "update_engine/payload_generator/cow_size_estimator.h"
36 #include "update_engine/update_metadata.pb.h"
37
38 using android::snapshot::CowWriter;
39
40 namespace chromeos_update_engine {
41
ProcessPartition(const chromeos_update_engine::PartitionUpdate & partition,const char * image_dir,size_t block_size)42 bool ProcessPartition(const chromeos_update_engine::PartitionUpdate& partition,
43 const char* image_dir,
44 size_t block_size) {
45 base::FilePath img_dir{image_dir};
46 auto target_img = img_dir.Append(partition.partition_name() + ".img");
47 auto output_cow = img_dir.Append(partition.partition_name() + ".cow");
48 FileDescriptorPtr target_img_fd = std::make_shared<EintrSafeFileDescriptor>();
49 if (!target_img_fd->Open(target_img.value().c_str(), O_RDONLY)) {
50 PLOG(ERROR) << "Failed to open " << target_img.value();
51 return false;
52 }
53 android::base::unique_fd output_fd{
54 open(output_cow.value().c_str(), O_RDWR | O_CREAT, 0744)};
55 if (output_fd < 0) {
56 PLOG(ERROR) << "Failed to open " << output_cow.value();
57 return false;
58 }
59
60 android::snapshot::CowWriter cow_writer{
61 {.block_size = static_cast<uint32_t>(block_size), .compression = "gz"}};
62 TEST_AND_RETURN_FALSE(cow_writer.Initialize(output_fd));
63 TEST_AND_RETURN_FALSE(CowDryRun(nullptr,
64 target_img_fd,
65 partition.operations(),
66 partition.merge_operations(),
67 block_size,
68 &cow_writer,
69 partition.new_partition_info().size(),
70 false));
71 TEST_AND_RETURN_FALSE(cow_writer.Finalize());
72 return true;
73 }
74
75 } // namespace chromeos_update_engine
76
77 using chromeos_update_engine::MetadataParseResult;
78 using chromeos_update_engine::PayloadMetadata;
79
main(int argc,const char * argv[])80 int main(int argc, const char* argv[]) {
81 if (argc != 3) {
82 printf("Usage: %s <payload.bin> <extracted target_file>\n", argv[0]);
83 return -1;
84 }
85 const char* payload_path = argv[1];
86 const char* images_dir = argv[2];
87 int payload_fd = open(payload_path, O_RDONLY);
88 if (payload_fd < 0) {
89 PLOG(ERROR) << "Failed to open payload file:";
90 return 1;
91 }
92 chromeos_update_engine::ScopedFdCloser closer{&payload_fd};
93 auto payload_size = chromeos_update_engine::utils::FileSize(payload_fd);
94 if (payload_size <= 0) {
95 PLOG(ERROR)
96 << "Couldn't determine size of payload file, or payload file is empty";
97 return 2;
98 }
99
100 PayloadMetadata payload_metadata;
101 auto payload = static_cast<unsigned char*>(
102 mmap(nullptr, payload_size, PROT_READ, MAP_PRIVATE, payload_fd, 0));
103
104 // C++ dark magic to ensure that |payload| is properly deallocated once the
105 // program exits.
106 auto munmap_deleter = [payload_size](auto payload) {
107 munmap(payload, payload_size);
108 };
109 std::unique_ptr<unsigned char, decltype(munmap_deleter)> munmapper{
110 payload, munmap_deleter};
111
112 if (payload == nullptr) {
113 PLOG(ERROR) << "Failed to mmap() payload file";
114 return 3;
115 }
116 if (payload_metadata.ParsePayloadHeader(payload, payload_size, nullptr) !=
117 chromeos_update_engine::MetadataParseResult::kSuccess) {
118 LOG(ERROR) << "Payload header parse failed!";
119 return 4;
120 }
121 chromeos_update_engine::DeltaArchiveManifest manifest;
122 if (!payload_metadata.GetManifest(payload, payload_size, &manifest)) {
123 LOG(ERROR) << "Failed to parse manifest!";
124 return 5;
125 }
126
127 size_t estimated_total_cow_size = 0;
128 size_t actual_total_cow_size = 0;
129
130 for (const auto& partition : manifest.partitions()) {
131 if (partition.estimate_cow_size() == 0) {
132 continue;
133 }
134 LOG(INFO) << partition.partition_name();
135 if (!ProcessPartition(partition, images_dir, manifest.block_size())) {
136 return 6;
137 }
138 base::FilePath img_dir{images_dir};
139 const auto output_cow =
140 img_dir.Append(partition.partition_name() + ".cow").value();
141 const auto actual_cow_size =
142 chromeos_update_engine::utils::FileSize(output_cow);
143 LOG(INFO) << partition.partition_name()
144 << ": estimated COW size is: " << partition.estimate_cow_size()
145 << ", actual COW size is: " << actual_cow_size
146 << ", estimated COW size is "
147 << (actual_cow_size - partition.estimate_cow_size()) * 100.0f /
148 actual_cow_size
149 << "% smaller";
150 estimated_total_cow_size += partition.estimate_cow_size();
151 actual_total_cow_size += actual_cow_size;
152 }
153
154 LOG(INFO) << "Total estimated COW size is: " << estimated_total_cow_size
155 << ", Total actual COW size is: " << actual_total_cow_size
156 << ", estimated COW size is "
157 << (actual_total_cow_size - estimated_total_cow_size) * 100.0f /
158 actual_total_cow_size
159 << "% smaller";
160 return 0;
161 }
162