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 #pragma once 26 27 #include <string> 28 #include <vector> 29 30 #include <fs_avb/types.h> 31 #include <fstab/fstab.h> 32 #include <libavb/libavb.h> 33 34 namespace android { 35 namespace fs_mgr { 36 37 // This class provides C++ bindings to interact with libavb, a small 38 // self-contained piece of code that's intended to be used in bootloaders. 39 // It mainly contains two functions: 40 // - ReadFromPartition(): to read AVB metadata from a given partition. 41 // It provides the implementation of AvbOps.read_from_partition() when 42 // reading metadata through libavb. 43 // - AvbSlotVerify(): the C++ binding of libavb->avb_slot_verify() to 44 // read and verify the metadata and store it into the out_data parameter. 45 // The caller MUST check the integrity of metadata against the 46 // androidboot.vbmeta.{hash_alg, size, digest} values from /proc/cmdline. 47 // e.g., see class AvbVerifier for more details. 48 // 49 class FsManagerAvbOps { 50 public: 51 FsManagerAvbOps(); 52 GetInstanceFromAvbOps(AvbOps * ops)53 static FsManagerAvbOps* GetInstanceFromAvbOps(AvbOps* ops) { 54 return reinterpret_cast<FsManagerAvbOps*>(ops->user_data); 55 } 56 57 AvbIOResult ReadFromPartition(const char* partition, int64_t offset, size_t num_bytes, 58 void* buffer, size_t* out_num_read); 59 60 AvbSlotVerifyResult AvbSlotVerify(const std::string& ab_suffix, AvbSlotVerifyFlags flags, 61 std::vector<VBMetaData>* out_vbmeta_images); 62 63 private: 64 std::string GetLogicalPath(const std::string& partition_name); 65 AvbOps avb_ops_; 66 Fstab fstab_; 67 }; 68 69 } // namespace fs_mgr 70 } // namespace android 71