383 lines
9.0 KiB
C++
383 lines
9.0 KiB
C++
/*
|
|
* Copyright (C) 2009 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.
|
|
*/
|
|
|
|
#define LOG_TAG "backup_data"
|
|
|
|
#include <androidfw/BackupHelpers.h>
|
|
#include <utils/ByteOrder.h>
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include <cutils/log.h>
|
|
|
|
namespace android {
|
|
|
|
static const bool DEBUG = false;
|
|
|
|
/*
|
|
* File Format (v1):
|
|
*
|
|
* All ints are stored little-endian.
|
|
*
|
|
* - An app_header_v1 struct.
|
|
* - The name of the package, utf-8, null terminated, padded to 4-byte boundary.
|
|
* - A sequence of zero or more key/value paires (entities), each with
|
|
* - A entity_header_v1 struct
|
|
* - The key, utf-8, null terminated, padded to 4-byte boundary.
|
|
* - The value, padded to 4 byte boundary
|
|
*/
|
|
|
|
const static int ROUND_UP[4] = { 0, 3, 2, 1 };
|
|
|
|
static inline size_t
|
|
round_up(size_t n)
|
|
{
|
|
return n + ROUND_UP[n % 4];
|
|
}
|
|
|
|
static inline size_t
|
|
padding_extra(size_t n)
|
|
{
|
|
return ROUND_UP[n % 4];
|
|
}
|
|
|
|
BackupDataWriter::BackupDataWriter(int fd)
|
|
:m_fd(fd),
|
|
m_status(NO_ERROR),
|
|
m_pos(0),
|
|
m_entityCount(0)
|
|
{
|
|
}
|
|
|
|
BackupDataWriter::~BackupDataWriter()
|
|
{
|
|
}
|
|
|
|
// Pad out anything they've previously written to the next 4 byte boundary.
|
|
status_t
|
|
BackupDataWriter::write_padding_for(int n)
|
|
{
|
|
ssize_t amt;
|
|
ssize_t paddingSize;
|
|
|
|
paddingSize = padding_extra(n);
|
|
if (paddingSize > 0) {
|
|
uint32_t padding = 0xbcbcbcbc;
|
|
if (DEBUG) ALOGI("writing %d padding bytes for %d", paddingSize, n);
|
|
amt = write(m_fd, &padding, paddingSize);
|
|
if (amt != paddingSize) {
|
|
m_status = errno;
|
|
return m_status;
|
|
}
|
|
m_pos += amt;
|
|
}
|
|
return NO_ERROR;
|
|
}
|
|
|
|
status_t
|
|
BackupDataWriter::WriteEntityHeader(const String8& key, size_t dataSize)
|
|
{
|
|
if (m_status != NO_ERROR) {
|
|
return m_status;
|
|
}
|
|
|
|
ssize_t amt;
|
|
|
|
amt = write_padding_for(m_pos);
|
|
if (amt != 0) {
|
|
return amt;
|
|
}
|
|
|
|
String8 k;
|
|
if (m_keyPrefix.length() > 0) {
|
|
k = m_keyPrefix;
|
|
k += ":";
|
|
k += key;
|
|
} else {
|
|
k = key;
|
|
}
|
|
if (DEBUG) {
|
|
ALOGD("Writing header: prefix='%s' key='%s' dataSize=%d", m_keyPrefix.string(),
|
|
key.string(), dataSize);
|
|
}
|
|
|
|
entity_header_v1 header;
|
|
ssize_t keyLen;
|
|
|
|
keyLen = k.length();
|
|
|
|
header.type = tolel(BACKUP_HEADER_ENTITY_V1);
|
|
header.keyLen = tolel(keyLen);
|
|
header.dataSize = tolel(dataSize);
|
|
|
|
if (DEBUG) ALOGI("writing entity header, %d bytes", sizeof(entity_header_v1));
|
|
amt = write(m_fd, &header, sizeof(entity_header_v1));
|
|
if (amt != sizeof(entity_header_v1)) {
|
|
m_status = errno;
|
|
return m_status;
|
|
}
|
|
m_pos += amt;
|
|
|
|
if (DEBUG) ALOGI("writing entity header key, %d bytes", keyLen+1);
|
|
amt = write(m_fd, k.string(), keyLen+1);
|
|
if (amt != keyLen+1) {
|
|
m_status = errno;
|
|
return m_status;
|
|
}
|
|
m_pos += amt;
|
|
|
|
amt = write_padding_for(keyLen+1);
|
|
|
|
m_entityCount++;
|
|
|
|
return amt;
|
|
}
|
|
|
|
status_t
|
|
BackupDataWriter::WriteEntityData(const void* data, size_t size)
|
|
{
|
|
if (DEBUG) ALOGD("Writing data: size=%lu", (unsigned long) size);
|
|
|
|
if (m_status != NO_ERROR) {
|
|
if (DEBUG) {
|
|
ALOGD("Not writing data - stream in error state %d (%s)", m_status, strerror(m_status));
|
|
}
|
|
return m_status;
|
|
}
|
|
|
|
// We don't write padding here, because they're allowed to call this several
|
|
// times with smaller buffers. We write it at the end of WriteEntityHeader
|
|
// instead.
|
|
ssize_t amt = write(m_fd, data, size);
|
|
if (amt != (ssize_t)size) {
|
|
m_status = errno;
|
|
if (DEBUG) ALOGD("write returned error %d (%s)", m_status, strerror(m_status));
|
|
return m_status;
|
|
}
|
|
m_pos += amt;
|
|
return NO_ERROR;
|
|
}
|
|
|
|
void
|
|
BackupDataWriter::SetKeyPrefix(const String8& keyPrefix)
|
|
{
|
|
m_keyPrefix = keyPrefix;
|
|
}
|
|
|
|
|
|
BackupDataReader::BackupDataReader(int fd)
|
|
:m_fd(fd),
|
|
m_done(false),
|
|
m_status(NO_ERROR),
|
|
m_pos(0),
|
|
m_entityCount(0)
|
|
{
|
|
memset(&m_header, 0, sizeof(m_header));
|
|
}
|
|
|
|
BackupDataReader::~BackupDataReader()
|
|
{
|
|
}
|
|
|
|
status_t
|
|
BackupDataReader::Status()
|
|
{
|
|
return m_status;
|
|
}
|
|
|
|
#define CHECK_SIZE(actual, expected) \
|
|
do { \
|
|
if ((actual) != (expected)) { \
|
|
if ((actual) == 0) { \
|
|
m_status = EIO; \
|
|
m_done = true; \
|
|
} else { \
|
|
m_status = errno; \
|
|
ALOGD("CHECK_SIZE(a=%ld e=%ld) failed at line %d m_status='%s'", \
|
|
long(actual), long(expected), __LINE__, strerror(m_status)); \
|
|
} \
|
|
return m_status; \
|
|
} \
|
|
} while(0)
|
|
#define SKIP_PADDING() \
|
|
do { \
|
|
status_t err = skip_padding(); \
|
|
if (err != NO_ERROR) { \
|
|
ALOGD("SKIP_PADDING FAILED at line %d", __LINE__); \
|
|
m_status = err; \
|
|
return err; \
|
|
} \
|
|
} while(0)
|
|
|
|
status_t
|
|
BackupDataReader::ReadNextHeader(bool* done, int* type)
|
|
{
|
|
*done = m_done;
|
|
if (m_status != NO_ERROR) {
|
|
return m_status;
|
|
}
|
|
|
|
int amt;
|
|
|
|
amt = skip_padding();
|
|
if (amt == EIO) {
|
|
*done = m_done = true;
|
|
return NO_ERROR;
|
|
}
|
|
else if (amt != NO_ERROR) {
|
|
return amt;
|
|
}
|
|
amt = read(m_fd, &m_header, sizeof(m_header));
|
|
*done = m_done = (amt == 0);
|
|
if (*done) {
|
|
return NO_ERROR;
|
|
}
|
|
CHECK_SIZE(amt, sizeof(m_header));
|
|
m_pos += sizeof(m_header);
|
|
if (type) {
|
|
*type = m_header.type;
|
|
}
|
|
|
|
// validate and fix up the fields.
|
|
m_header.type = fromlel(m_header.type);
|
|
switch (m_header.type)
|
|
{
|
|
case BACKUP_HEADER_ENTITY_V1:
|
|
{
|
|
m_header.entity.keyLen = fromlel(m_header.entity.keyLen);
|
|
if (m_header.entity.keyLen <= 0) {
|
|
ALOGD("Entity header at %d has keyLen<=0: 0x%08x\n", (int)m_pos,
|
|
(int)m_header.entity.keyLen);
|
|
m_status = EINVAL;
|
|
}
|
|
m_header.entity.dataSize = fromlel(m_header.entity.dataSize);
|
|
m_entityCount++;
|
|
|
|
// read the rest of the header (filename)
|
|
size_t size = m_header.entity.keyLen;
|
|
char* buf = m_key.lockBuffer(size);
|
|
if (buf == NULL) {
|
|
m_status = ENOMEM;
|
|
return m_status;
|
|
}
|
|
int amt = read(m_fd, buf, size+1);
|
|
CHECK_SIZE(amt, (int)size+1);
|
|
m_key.unlockBuffer(size);
|
|
m_pos += size+1;
|
|
SKIP_PADDING();
|
|
m_dataEndPos = m_pos + m_header.entity.dataSize;
|
|
|
|
break;
|
|
}
|
|
default:
|
|
ALOGD("Chunk header at %d has invalid type: 0x%08x",
|
|
(int)(m_pos - sizeof(m_header)), (int)m_header.type);
|
|
m_status = EINVAL;
|
|
}
|
|
|
|
return m_status;
|
|
}
|
|
|
|
bool
|
|
BackupDataReader::HasEntities()
|
|
{
|
|
return m_status == NO_ERROR && m_header.type == BACKUP_HEADER_ENTITY_V1;
|
|
}
|
|
|
|
status_t
|
|
BackupDataReader::ReadEntityHeader(String8* key, size_t* dataSize)
|
|
{
|
|
if (m_status != NO_ERROR) {
|
|
return m_status;
|
|
}
|
|
if (m_header.type != BACKUP_HEADER_ENTITY_V1) {
|
|
return EINVAL;
|
|
}
|
|
*key = m_key;
|
|
*dataSize = m_header.entity.dataSize;
|
|
return NO_ERROR;
|
|
}
|
|
|
|
status_t
|
|
BackupDataReader::SkipEntityData()
|
|
{
|
|
if (m_status != NO_ERROR) {
|
|
return m_status;
|
|
}
|
|
if (m_header.type != BACKUP_HEADER_ENTITY_V1) {
|
|
return EINVAL;
|
|
}
|
|
if (m_header.entity.dataSize > 0) {
|
|
int pos = lseek(m_fd, m_dataEndPos, SEEK_SET);
|
|
if (pos == -1) {
|
|
return errno;
|
|
}
|
|
m_pos = pos;
|
|
}
|
|
SKIP_PADDING();
|
|
return NO_ERROR;
|
|
}
|
|
|
|
ssize_t
|
|
BackupDataReader::ReadEntityData(void* data, size_t size)
|
|
{
|
|
if (m_status != NO_ERROR) {
|
|
return -1;
|
|
}
|
|
int remaining = m_dataEndPos - m_pos;
|
|
//ALOGD("ReadEntityData size=%d m_pos=0x%x m_dataEndPos=0x%x remaining=%d\n",
|
|
// size, m_pos, m_dataEndPos, remaining);
|
|
if (remaining <= 0) {
|
|
return 0;
|
|
}
|
|
if (((int)size) > remaining) {
|
|
size = remaining;
|
|
}
|
|
//ALOGD(" reading %d bytes", size);
|
|
int amt = read(m_fd, data, size);
|
|
if (amt < 0) {
|
|
m_status = errno;
|
|
return -1;
|
|
}
|
|
if (amt == 0) {
|
|
m_status = EIO;
|
|
m_done = true;
|
|
}
|
|
m_pos += amt;
|
|
return amt;
|
|
}
|
|
|
|
status_t
|
|
BackupDataReader::skip_padding()
|
|
{
|
|
ssize_t amt;
|
|
ssize_t paddingSize;
|
|
|
|
paddingSize = padding_extra(m_pos);
|
|
if (paddingSize > 0) {
|
|
uint32_t padding;
|
|
amt = read(m_fd, &padding, paddingSize);
|
|
CHECK_SIZE(amt, paddingSize);
|
|
m_pos += amt;
|
|
}
|
|
return NO_ERROR;
|
|
}
|
|
|
|
|
|
} // namespace android
|