1 //
2 // Copyright (C) 2012 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 #ifndef UPDATE_ENGINE_PAYLOAD_CONSUMER_FILESYSTEM_VERIFIER_ACTION_H_
18 #define UPDATE_ENGINE_PAYLOAD_CONSUMER_FILESYSTEM_VERIFIER_ACTION_H_
19 
20 #include <sys/stat.h>
21 #include <sys/types.h>
22 
23 #include <memory>
24 #include <string>
25 #include <utility>
26 #include <vector>
27 
28 #include <brillo/message_loops/message_loop.h>
29 
30 #include "update_engine/common/action.h"
31 #include "update_engine/common/hash_calculator.h"
32 #include "update_engine/common/scoped_task_id.h"
33 #include "update_engine/payload_consumer/file_descriptor.h"
34 #include "update_engine/payload_consumer/install_plan.h"
35 #include "update_engine/payload_consumer/verity_writer_interface.h"
36 
37 // This action will hash all the partitions of the target slot involved in the
38 // update. The hashes are then verified against the ones in the InstallPlan.
39 // If the target hash does not match, the action will fail. In case of failure,
40 // the error code will depend on whether the source slot hashes are provided and
41 // match.
42 
43 namespace chromeos_update_engine {
44 
45 // The step FilesystemVerifier is on. On kVerifyTargetHash it computes the hash
46 // on the target partitions based on the already populated size and verifies it
47 // matches the one in the target_hash in the InstallPlan.
48 // If the hash matches, then we skip the kVerifySourceHash step, otherwise we
49 // need to check if the source is the root cause of the mismatch.
50 enum class VerifierStep {
51   kVerifyTargetHash,
52   kVerifySourceHash,
53 };
54 
55 class FilesystemVerifyDelegate {
56  public:
57   virtual ~FilesystemVerifyDelegate() = default;
58   virtual void OnVerifyProgressUpdate(double progress) = 0;
59 };
60 
61 class FilesystemVerifierAction : public InstallPlanAction {
62  public:
FilesystemVerifierAction(DynamicPartitionControlInterface * dynamic_control)63   explicit FilesystemVerifierAction(
64       DynamicPartitionControlInterface* dynamic_control)
65       : verity_writer_(verity_writer::CreateVerityWriter()),
66         dynamic_control_(dynamic_control) {
67     CHECK(dynamic_control_);
68   }
69 
70   ~FilesystemVerifierAction() override = default;
71 
72   void PerformAction() override;
73   void TerminateProcessing() override;
74 
75   // Used for listening to progress updates
set_delegate(FilesystemVerifyDelegate * delegate)76   void set_delegate(FilesystemVerifyDelegate* delegate) {
77     this->delegate_ = delegate;
78   }
get_delegate()79   [[nodiscard]] FilesystemVerifyDelegate* get_delegate() const {
80     return this->delegate_;
81   }
82 
83   // Debugging/logging
StaticType()84   static std::string StaticType() { return "FilesystemVerifierAction"; }
Type()85   std::string Type() const override { return StaticType(); }
86 
87  private:
88   friend class FilesystemVerifierActionTestDelegate;
89   // Wrapper function that schedules calls of EncodeFEC. Returns true on success
90   void WriteVerityData(FileDescriptor* fd,
91                        void* buffer,
92                        const size_t buffer_size);
93   void WriteVerityAndHashPartition(const off64_t start_offset,
94                                    const off64_t end_offset,
95                                    void* buffer,
96                                    const size_t buffer_size);
97   void HashPartition(const off64_t start_offset,
98                      const off64_t end_offset,
99                      void* buffer,
100                      const size_t buffer_size);
101 
102   // Return true if we need to write verity bytes.
103   bool ShouldWriteVerity();
104   // Starts the hashing of the current partition. If there aren't any partitions
105   // remaining to be hashed, it finishes the action.
106   void StartPartitionHashing();
107 
108   const std::string& GetPartitionPath() const;
109 
110   bool IsVABC(const InstallPlan::Partition& partition) const;
111 
112   size_t GetPartitionSize() const;
113 
114   // When the read is done, finalize the hash checking of the current partition
115   // and continue checking the next one.
116   void FinishPartitionHashing();
117 
118   // Cleans up all the variables we use for async operations and tells the
119   // ActionProcessor we're done w/ |code| as passed in. |cancelled_| should be
120   // true if TerminateProcessing() was called.
121   void Cleanup(ErrorCode code);
122 
123   // Invoke delegate callback to report progress, if delegate is not null
124   void UpdateProgress(double progress);
125 
126   // Updates progress of current partition. |progress| should be in range [0,
127   // 1], and it will be scaled appropriately with # of partitions.
128   void UpdatePartitionProgress(double progress);
129 
130   // Initialize read_fd_ and write_fd_
131   bool InitializeFd(const std::string& part_path);
132   bool InitializeFdVABC(bool should_write_verity);
133 
134   // The type of the partition that we are verifying.
135   VerifierStep verifier_step_ = VerifierStep::kVerifyTargetHash;
136 
137   // The index in the install_plan_.partitions vector of the partition currently
138   // being hashed.
139   size_t partition_index_{0};
140 
141   // If not null, the FileDescriptor used to read from the device.
142   // verity writer might attempt to write to this fd, if verity is enabled.
143   std::unique_ptr<FileDescriptor> partition_fd_;
144 
145   // Buffer for storing data we read.
146   brillo::Blob buffer_;
147 
148   bool cancelled_{false};  // true if the action has been cancelled.
149 
150   // Calculates the hash of the data.
151   std::unique_ptr<HashCalculator> hasher_;
152 
153   // Write verity data of the current partition.
154   std::unique_ptr<VerityWriterInterface> verity_writer_;
155 
156   // Verifies the untouched dynamic partitions for partial updates.
157   DynamicPartitionControlInterface* dynamic_control_{nullptr};
158 
159   // Reads and hashes this many bytes from the head of the input stream. When
160   // the partition starts to be hashed, this field is initialized from the
161   // corresponding InstallPlan::Partition size which is the total size
162   // update_engine is expected to write, and may be smaller than the size of the
163   // partition in gpt.
164   uint64_t partition_size_{0};
165 
166   // The byte offset that we are reading in the current partition.
167   uint64_t offset_{0};
168 
169   // The end offset of filesystem data, first byte position of hashtree.
170   uint64_t filesystem_data_end_{0};
171 
172   // An observer that observes progress updates of this action.
173   FilesystemVerifyDelegate* delegate_{};
174 
175   // Callback that should be cancelled on |TerminateProcessing|. Usually this
176   // points to pending read callbacks from async stream.
177   ScopedTaskId pending_task_id_;
178 
179   // Cumulative sum of partition sizes. Used for progress report.
180   // This vector will always start with 0, and end with total size of all
181   // partitions.
182   std::vector<size_t> partition_weight_;
183 
184   DISALLOW_COPY_AND_ASSIGN(FilesystemVerifierAction);
185 };
186 
187 }  // namespace chromeos_update_engine
188 
189 #endif  // UPDATE_ENGINE_PAYLOAD_CONSUMER_FILESYSTEM_VERIFIER_ACTION_H_
190