1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Permission is hereby granted, free of charge, to any person
5  * obtaining a copy of this software and associated documentation
6  * files (the "Software"), to deal in the Software without
7  * restriction, including without limitation the rights to use, copy,
8  * modify, merge, publish, distribute, sublicense, and/or sell copies
9  * of the Software, and to permit persons to whom the Software is
10  * furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #ifndef __CORE_FS_MGR_PRIV_AVB_OPS_H
26 #define __CORE_FS_MGR_PRIV_AVB_OPS_H
27 
28 #include <map>
29 #include <string>
30 
31 #include <libavb/libavb.h>
32 
33 #include "fs_mgr.h"
34 
35 // This class provides C++ bindings to interact with libavb, a small
36 // self-contained piece of code that's intended to be used in bootloaders.
37 // It mainly contains two functions:
38 //   - ReadFromPartition(): to read AVB metadata from a given partition.
39 //     It provides the implementation of AvbOps.read_from_partition() when
40 //     reading metadata through libavb.
41 //   - AvbSlotVerify(): the C++ binding of libavb->avb_slot_verify() to
42 //     read and verify the metadata and store it into the out_data parameter.
43 //     The caller MUST check the integrity of metadata against the
44 //     androidboot.vbmeta.{hash_alg, size, digest} values from /proc/cmdline.
45 //     e.g., see class FsManagerAvbVerifier for more details.
46 //
47 class FsManagerAvbOps {
48   public:
49     FsManagerAvbOps(const fstab& fstab);
50     FsManagerAvbOps(std::map<std::string, std::string>&& by_name_symlink_map);
51 
GetInstanceFromAvbOps(AvbOps * ops)52     static FsManagerAvbOps* GetInstanceFromAvbOps(AvbOps* ops) {
53         return reinterpret_cast<FsManagerAvbOps*>(ops->user_data);
54     }
55 
56     AvbIOResult ReadFromPartition(const char* partition, int64_t offset, size_t num_bytes,
57                                   void* buffer, size_t* out_num_read);
58 
59     AvbSlotVerifyResult AvbSlotVerify(const std::string& ab_suffix, bool allow_verification_error,
60                                       AvbSlotVerifyData** out_data);
61 
62   private:
63     void InitializeAvbOps();
64 
65     AvbOps avb_ops_;
66     std::map<std::string, std::string> by_name_symlink_map_;
67 };
68 #endif /* __CORE_FS_MGR_PRIV_AVB_OPS_H */
69