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 #ifndef UPDATE_ENGINE_PAYLOAD_CONSUMER_FEC_FILE_DESCRIPTOR_H_ 18 #define UPDATE_ENGINE_PAYLOAD_CONSUMER_FEC_FILE_DESCRIPTOR_H_ 19 20 #include <fec/io.h> 21 22 #include "update_engine/payload_consumer/file_descriptor.h" 23 24 // A FileDescriptor implementation with error correction based on the "libfec" 25 // library. The libfec on the running system allows to parse the error 26 // correction blocks stored in partitions that have verity and error correction 27 // enabled. This information is present in the raw block device, but of course 28 // not available via the dm-verity block device. 29 30 namespace chromeos_update_engine { 31 32 // An error corrected file based on FEC. 33 class FecFileDescriptor : public FileDescriptor { 34 public: 35 FecFileDescriptor() = default; 36 ~FecFileDescriptor() = default; 37 38 // Interface methods. 39 bool Open(const char* path, int flags, mode_t mode) override; 40 bool Open(const char* path, int flags) override; 41 ssize_t Read(void* buf, size_t count) override; 42 ssize_t Write(const void* buf, size_t count) override; 43 off64_t Seek(off64_t offset, int whence) override; 44 uint64_t BlockDevSize() override; 45 bool BlkIoctl(int request, 46 uint64_t start, 47 uint64_t length, 48 int* result) override; Flush()49 bool Flush() override { return true; } 50 bool Close() override; IsSettingErrno()51 bool IsSettingErrno() override { return true; } IsOpen()52 bool IsOpen() override { 53 // The bool operator on the fec::io class tells whether the internal 54 // handle is open. 55 return static_cast<bool>(fh_); 56 } 57 58 protected: 59 fec::io fh_; 60 uint64_t dev_size_{0}; 61 }; 62 63 } // namespace chromeos_update_engine 64 65 #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_FEC_FILE_DESCRIPTOR_H_ 66