xref: /aosp_15_r20/bootable/recovery/update_verifier/include/update_verifier/update_verifier.h (revision e7c364b630b241adcb6c7726a21055250b91fdac)
1 /*
2  * Copyright (C) 2017 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 #pragma once
18 
19 #include <functional>
20 #include <map>
21 #include <string>
22 #include <vector>
23 
24 #include <snapuserd/snapuserd_client.h>
25 #include "otautil/rangeset.h"
26 
27 // The update verifier performs verification upon the first boot to a new slot on A/B devices.
28 // During the verification, it reads all the blocks in the care_map. And if a failure happens,
29 // it rejects the current boot and triggers a fallback.
30 
31 // Note that update_verifier should be backward compatible to not reject care_map.txt from old
32 // releases, which could otherwise fail to boot into the new release. For example, we've changed
33 // the care_map format between N and O. An O update_verifier would fail to work with N care_map.txt.
34 // This could be a result of sideloading an O OTA while the device having a pending N update.
35 int update_verifier(int argc, char** argv);
36 
37 // The UpdateVerifier parses the content in the care map, and continues to verify the
38 // partitions by reading the cared blocks if there's no format error in the file. Otherwise,
39 // it should skip the verification to avoid bricking the device.
40 class UpdateVerifier {
41  public:
42   UpdateVerifier();
43 
44   // This function tries to process the care_map.pb as protobuf message; and falls back to use
45   // care_map.txt if the pb format file doesn't exist. If the parsing succeeds, put the result
46   // of the pair <partition_name, ranges> into the |partition_map_|.
47   bool ParseCareMap();
48 
49   // Verifies the new boot by reading all the cared blocks for partitions in |partition_map_|.
50   bool VerifyPartitions();
51 
52  private:
53   friend class UpdateVerifierTest;
54   // Finds all the dm-enabled partitions, and returns a map of <partition_name, block_device>.
55   std::map<std::string, std::string> FindDmPartitions();
56 
57   // Returns true if we successfully read the blocks in |ranges| of the |dm_block_device|.
58   bool ReadBlocks(const std::string partition_name, const std::string& dm_block_device,
59                   const RangeSet& ranges);
60 
61   // Functions to override the care_map_prefix_ and property_reader_, used in test only.
62   void set_care_map_prefix(const std::string& prefix);
63   void set_property_reader(const std::function<std::string(const std::string&)>& property_reader);
64 
65   std::map<std::string, RangeSet> partition_map_;
66   // The path to the care_map excluding the filename extension; default value:
67   // "/data/ota_package/care_map"
68   std::string care_map_prefix_;
69 
70   // The function to read the device property; default value: android::base::GetProperty()
71   std::function<std::string(const std::string&)> property_reader_;
72 
73   // Check if snapuserd daemon has already completed the update verification
74   // Applicable only for VABC with userspace snapshots
75   bool CheckVerificationStatus();
76 };
77