blob: a5900377abb49129c345d573bf91a295c711dbfd [file] [log] [blame]
/*
* Copyright (C) 2018 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.
*/
#include <fcntl.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <android-base/file.h>
#include <ext4_utils/ext4_utils.h>
#include <openssl/sha.h>
#include <uuid/uuid.h>
#include "utility.h"
namespace android {
namespace fs_mgr {
bool GetDescriptorSize(int fd, uint64_t* size) {
struct stat s;
if (fstat(fd, &s) < 0) {
PERROR << __PRETTY_FUNCTION__ << "fstat failed";
return false;
}
if (S_ISBLK(s.st_mode)) {
*size = get_block_device_size(fd);
return *size != 0;
}
int64_t result = SeekFile64(fd, 0, SEEK_END);
if (result == -1) {
PERROR << __PRETTY_FUNCTION__ << "lseek failed";
return false;
}
*size = result;
return true;
}
int64_t SeekFile64(int fd, int64_t offset, int whence) {
static_assert(sizeof(off_t) == sizeof(int64_t), "Need 64-bit lseek");
return lseek(fd, offset, whence);
}
int64_t GetPrimaryMetadataOffset(const LpMetadataGeometry& geometry, uint32_t slot_number) {
CHECK(slot_number < geometry.metadata_slot_count);
int64_t offset = LP_METADATA_GEOMETRY_SIZE + geometry.metadata_max_size * slot_number;
CHECK(offset + geometry.metadata_max_size <=
int64_t(geometry.first_logical_sector * LP_SECTOR_SIZE));
return offset;
}
int64_t GetBackupMetadataOffset(const LpMetadataGeometry& geometry, uint32_t slot_number) {
CHECK(slot_number < geometry.metadata_slot_count);
int64_t start = int64_t(-LP_METADATA_GEOMETRY_SIZE) -
int64_t(geometry.metadata_max_size) * geometry.metadata_slot_count;
return start + int64_t(geometry.metadata_max_size * slot_number);
}
void SHA256(const void* data, size_t length, uint8_t out[32]) {
SHA256_CTX c;
SHA256_Init(&c);
SHA256_Update(&c, data, length);
SHA256_Final(out, &c);
}
std::string GetPartitionGuid(const LpMetadataPartition& partition) {
// 32 hex characters, four hyphens. Unfortunately libext2_uuid provides no
// macro to assist with buffer sizing.
static const size_t kGuidLen = 36;
char buffer[kGuidLen + 1];
uuid_unparse_upper(partition.guid, buffer);
return buffer;
}
uint32_t SlotNumberForSlotSuffix(const std::string& suffix) {
if (suffix.empty()) {
return 0;
}
if (suffix.size() != 2 || suffix[0] != '_' || suffix[1] < 'a') {
LERROR << __PRETTY_FUNCTION__ << "slot '" << suffix
<< "' does not have a recognized format.";
return 0;
}
return suffix[1] - 'a';
}
} // namespace fs_mgr
} // namespace android