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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ___FEC_IO_H___
#define ___FEC_IO_H___
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <mincrypt/rsa.h>
#ifdef __cplusplus
extern "C" {
#endif
#ifndef SHA256_DIGEST_LENGTH
#define SHA256_DIGEST_LENGTH 32
#endif
#define FEC_BLOCKSIZE 4096
#define FEC_DEFAULT_ROOTS 2
#define FEC_MAGIC 0xFECFECFE
#define FEC_VERSION 0
/* disk format for the header */
struct fec_header {
uint32_t magic;
uint32_t version;
uint32_t size;
uint32_t roots;
uint32_t fec_size;
uint64_t inp_size;
uint8_t hash[SHA256_DIGEST_LENGTH];
};
struct fec_status {
int flags;
int mode;
uint64_t errors;
uint64_t data_size;
uint64_t size;
};
struct fec_ecc_metadata {
bool valid;
uint32_t roots;
uint64_t blocks;
uint64_t rounds;
uint64_t start;
};
struct fec_verity_metadata {
bool disabled;
uint64_t data_size;
uint8_t signature[RSANUMBYTES];
uint8_t ecc_signature[RSANUMBYTES];
const char *table;
uint32_t table_length;
};
/* flags for fec_open */
enum {
FEC_FS_EXT4 = 1 << 0,
FEC_FS_SQUASH = 1 << 1,
FEC_VERITY_DISABLE = 1 << 8
};
struct fec_handle;
/* file access */
extern int fec_open(struct fec_handle **f, const char *path, int mode,
int flags, int roots);
extern int fec_close(struct fec_handle *f);
extern int fec_verity_set_status(struct fec_handle *f, bool enabled);
extern int fec_verity_get_metadata(struct fec_handle *f,
struct fec_verity_metadata *data);
extern int fec_ecc_get_metadata(struct fec_handle *f,
struct fec_ecc_metadata *data);
extern int fec_get_status(struct fec_handle *f, struct fec_status *s);
extern int fec_seek(struct fec_handle *f, int64_t offset, int whence);
extern ssize_t fec_read(struct fec_handle *f, void *buf, size_t count);
extern ssize_t fec_pread(struct fec_handle *f, void *buf, size_t count,
uint64_t offset);
#ifdef __cplusplus
} /* extern "C" */
#include <memory>
#include <string>
/* C++ wrappers for fec_handle and operations */
namespace fec {
using handle = std::unique_ptr<fec_handle, decltype(&fec_close)>;
class io {
public:
io() : handle_(nullptr, fec_close) {}
io(const std::string& fn, int mode = O_RDONLY, int flags = 0,
int roots = FEC_DEFAULT_ROOTS) : handle_(nullptr, fec_close) {
open(fn, mode, flags, roots);
}
explicit operator bool() const {
return !!handle_;
}
bool open(const std::string& fn, int mode = O_RDONLY, int flags = 0,
int roots = FEC_DEFAULT_ROOTS)
{
fec_handle *fh = nullptr;
int rc = fec_open(&fh, fn.c_str(), mode, flags, roots);
if (!rc) {
handle_.reset(fh);
}
return !rc;
}
bool close() {
return !fec_close(handle_.release());
}
bool seek(int64_t offset, int whence) {
return !fec_seek(handle_.get(), offset, whence);
}
ssize_t read(void *buf, size_t count) {
return fec_read(handle_.get(), buf, count);
}
ssize_t pread(void *buf, size_t count, uint64_t offset) {
return fec_pread(handle_.get(), buf, count, offset);
}
bool get_status(fec_status& status) {
return !fec_get_status(handle_.get(), &status);
}
bool get_verity_metadata(fec_verity_metadata& data) {
return !fec_verity_get_metadata(handle_.get(), &data);
}
bool has_verity() {
fec_verity_metadata data;
return get_verity_metadata(data);
}
bool get_ecc_metadata(fec_ecc_metadata& data) {
return !fec_ecc_get_metadata(handle_.get(), &data);
}
bool has_ecc() {
fec_ecc_metadata data;
return get_ecc_metadata(data) && data.valid;
}
bool set_verity_status(bool enabled) {
return !fec_verity_set_status(handle_.get(), enabled);
}
private:
handle handle_;
};
}
#endif
#endif /* ___FEC_IO_H___ */
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