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 <string>
24 #include <vector>
25 
26 #include <brillo/streams/stream.h>
27 #include <gtest/gtest_prod.h>  // for FRIEND_TEST
28 
29 #include "update_engine/common/action.h"
30 #include "update_engine/common/hash_calculator.h"
31 #include "update_engine/payload_consumer/install_plan.h"
32 
33 // This action will hash all the partitions of a single slot involved in the
34 // update (either source or target slot). The hashes are then either stored in
35 // the InstallPlan (for source partitions) or verified against it (for target
36 // partitions).
37 
38 namespace chromeos_update_engine {
39 
40 // The mode we are running the FilesystemVerifier on. On kComputeSourceHash mode
41 // it computes the source_hash of all the partitions in the InstallPlan, based
42 // on the already populated source_size values. On kVerifyTargetHash it computes
43 // the hash on the target partitions based on the already populated size and
44 // verifies it matches the one in the target_hash in the InstallPlan.
45 enum class VerifierMode {
46   kComputeSourceHash,
47   kVerifyTargetHash,
48   kVerifySourceHash,
49 };
50 
51 class FilesystemVerifierAction : public InstallPlanAction {
52  public:
53   FilesystemVerifierAction(const BootControlInterface* boot_control,
54                            VerifierMode verifier_mode);
55 
56   void PerformAction() override;
57   void TerminateProcessing() override;
58 
59   // Used for testing. Return true if Cleanup() has not yet been called due
60   // to a callback upon the completion or cancellation of the verifier action.
61   // A test should wait until IsCleanupPending() returns false before
62   // terminating the main loop.
63   bool IsCleanupPending() const;
64 
65   // Debugging/logging
StaticType()66   static std::string StaticType() { return "FilesystemVerifierAction"; }
Type()67   std::string Type() const override { return StaticType(); }
68 
69  private:
70   friend class FilesystemVerifierActionTest;
71   FRIEND_TEST(FilesystemVerifierActionTest,
72               RunAsRootDetermineFilesystemSizeTest);
73 
74   // Starts the hashing of the current partition. If there aren't any partitions
75   // remaining to be hashed, if finishes the action.
76   void StartPartitionHashing();
77 
78   // Schedules the asynchronous read of the filesystem.
79   void ScheduleRead();
80 
81   // Called from the main loop when a single read from |src_stream_| succeeds or
82   // fails, calling OnReadDoneCallback() and OnReadErrorCallback() respectively.
83   void OnReadDoneCallback(size_t bytes_read);
84   void OnReadErrorCallback(const brillo::Error* error);
85 
86   // When the read is done, finalize the hash checking of the current partition
87   // and continue checking the next one.
88   void FinishPartitionHashing();
89 
90   // Cleans up all the variables we use for async operations and tells the
91   // ActionProcessor we're done w/ |code| as passed in. |cancelled_| should be
92   // true if TerminateProcessing() was called.
93   void Cleanup(ErrorCode code);
94 
95   // The type of the partition that we are verifying.
96   VerifierMode verifier_mode_;
97 
98   // The BootControlInterface used to get the partitions based on the slots.
99   const BootControlInterface* const boot_control_;
100 
101   // The index in the install_plan_.partitions vector of the partition currently
102   // being hashed.
103   size_t partition_index_{0};
104 
105   // If not null, the FileStream used to read from the device.
106   brillo::StreamPtr src_stream_;
107 
108   // Buffer for storing data we read.
109   brillo::Blob buffer_;
110 
111   bool read_done_{false};  // true if reached EOF on the input stream.
112   bool cancelled_{false};  // true if the action has been cancelled.
113 
114   // The install plan we're passed in via the input pipe.
115   InstallPlan install_plan_;
116 
117   // Calculates the hash of the data.
118   std::unique_ptr<HashCalculator> hasher_;
119 
120   // Reads and hashes this many bytes from the head of the input stream. This
121   // field is initialized from the corresponding InstallPlan::Partition size,
122   // when the partition starts to be hashed.
123   int64_t remaining_size_{0};
124 
125   DISALLOW_COPY_AND_ASSIGN(FilesystemVerifierAction);
126 };
127 
128 }  // namespace chromeos_update_engine
129 
130 #endif  // UPDATE_ENGINE_PAYLOAD_CONSUMER_FILESYSTEM_VERIFIER_ACTION_H_
131