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/*
* 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 "idmap2/Idmap.h"
#include <algorithm>
#include <iostream>
#include <iterator>
#include <limits>
#include <map>
#include <memory>
#include <set>
#include <string>
#include <utility>
#include <vector>
#include "android-base/macros.h"
#include "android-base/stringprintf.h"
#include "androidfw/AssetManager2.h"
#include "idmap2/ResourceMapping.h"
#include "idmap2/ResourceUtils.h"
#include "idmap2/Result.h"
#include "idmap2/SysTrace.h"
#include "idmap2/ZipFile.h"
#include "utils/String16.h"
#include "utils/String8.h"
namespace android::idmap2 {
namespace {
bool WARN_UNUSED Read8(std::istream& stream, uint8_t* out) {
uint8_t value;
if (stream.read(reinterpret_cast<char*>(&value), sizeof(uint8_t))) {
*out = value;
return true;
}
return false;
}
bool WARN_UNUSED Read32(std::istream& stream, uint32_t* out) {
uint32_t value;
if (stream.read(reinterpret_cast<char*>(&value), sizeof(uint32_t))) {
*out = dtohl(value);
return true;
}
return false;
}
bool WARN_UNUSED ReadBuffer(std::istream& stream, std::unique_ptr<uint8_t[]>* out, size_t length) {
auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[length]);
if (stream.read(reinterpret_cast<char*>(buffer.get()), length)) {
*out = std::move(buffer);
return true;
}
return false;
}
// a string is encoded as a kIdmapStringLength char array; the array is always null-terminated
bool WARN_UNUSED ReadString256(std::istream& stream, char out[kIdmapStringLength]) {
char buf[kIdmapStringLength];
memset(buf, 0, sizeof(buf));
if (!stream.read(buf, sizeof(buf))) {
return false;
}
if (buf[sizeof(buf) - 1] != '\0') {
return false;
}
memcpy(out, buf, sizeof(buf));
return true;
}
Result<std::string> ReadString(std::istream& stream) {
uint32_t size;
if (!Read32(stream, &size)) {
return Error("failed to read string size");
}
if (size == 0) {
return std::string("");
}
std::string buf(size, '\0');
if (!stream.read(buf.data(), size)) {
return Error("failed to read string of size %u", size);
}
// buf is guaranteed to be null terminated (with enough nulls to end on a word boundary)
buf.resize(strlen(buf.c_str()));
return buf;
}
Result<uint32_t> GetCrc(const ZipFile& zip) {
const Result<uint32_t> a = zip.Crc("resources.arsc");
const Result<uint32_t> b = zip.Crc("AndroidManifest.xml");
return a && b
? Result<uint32_t>(*a ^ *b)
: Error("failed to get CRC for \"%s\"", a ? "AndroidManifest.xml" : "resources.arsc");
}
} // namespace
std::unique_ptr<const IdmapHeader> IdmapHeader::FromBinaryStream(std::istream& stream) {
std::unique_ptr<IdmapHeader> idmap_header(new IdmapHeader());
if (!Read32(stream, &idmap_header->magic_) || !Read32(stream, &idmap_header->version_) ||
!Read32(stream, &idmap_header->target_crc_) || !Read32(stream, &idmap_header->overlay_crc_) ||
!ReadString256(stream, idmap_header->target_path_) ||
!ReadString256(stream, idmap_header->overlay_path_)) {
return nullptr;
}
auto debug_str = ReadString(stream);
if (!debug_str) {
return nullptr;
}
idmap_header->debug_info_ = std::move(*debug_str);
return std::move(idmap_header);
}
Result<Unit> IdmapHeader::IsUpToDate() const {
if (magic_ != kIdmapMagic) {
return Error("bad magic: actual 0x%08x, expected 0x%08x", magic_, kIdmapMagic);
}
if (version_ != kIdmapCurrentVersion) {
return Error("bad version: actual 0x%08x, expected 0x%08x", version_, kIdmapCurrentVersion);
}
const std::unique_ptr<const ZipFile> target_zip = ZipFile::Open(target_path_);
if (!target_zip) {
return Error("failed to open target %s", GetTargetPath().to_string().c_str());
}
Result<uint32_t> target_crc = GetCrc(*target_zip);
if (!target_crc) {
return Error("failed to get target crc");
}
if (target_crc_ != *target_crc) {
return Error("bad target crc: idmap version 0x%08x, file system version 0x%08x", target_crc_,
*target_crc);
}
const std::unique_ptr<const ZipFile> overlay_zip = ZipFile::Open(overlay_path_);
if (!overlay_zip) {
return Error("failed to open overlay %s", GetOverlayPath().to_string().c_str());
}
Result<uint32_t> overlay_crc = GetCrc(*overlay_zip);
if (!overlay_crc) {
return Error("failed to get overlay crc");
}
if (overlay_crc_ != *overlay_crc) {
return Error("bad overlay crc: idmap version 0x%08x, file system version 0x%08x", overlay_crc_,
*overlay_crc);
}
return Unit{};
}
std::unique_ptr<const IdmapData::Header> IdmapData::Header::FromBinaryStream(std::istream& stream) {
std::unique_ptr<IdmapData::Header> idmap_data_header(new IdmapData::Header());
if (!Read8(stream, &idmap_data_header->target_package_id_) ||
!Read8(stream, &idmap_data_header->overlay_package_id_) ||
!Read32(stream, &idmap_data_header->target_entry_count) ||
!Read32(stream, &idmap_data_header->overlay_entry_count) ||
!Read32(stream, &idmap_data_header->string_pool_index_offset) ||
!Read32(stream, &idmap_data_header->string_pool_len)) {
return nullptr;
}
return std::move(idmap_data_header);
}
std::unique_ptr<const IdmapData> IdmapData::FromBinaryStream(std::istream& stream) {
std::unique_ptr<IdmapData> data(new IdmapData());
data->header_ = IdmapData::Header::FromBinaryStream(stream);
if (!data->header_) {
return nullptr;
}
// Read the mapping of target resource id to overlay resource value.
for (size_t i = 0; i < data->header_->GetTargetEntryCount(); i++) {
TargetEntry target_entry{};
if (!Read32(stream, &target_entry.target_id) || !Read8(stream, &target_entry.data_type) ||
!Read32(stream, &target_entry.data_value)) {
return nullptr;
}
data->target_entries_.emplace_back(target_entry);
}
// Read the mapping of overlay resource id to target resource id.
for (size_t i = 0; i < data->header_->GetOverlayEntryCount(); i++) {
OverlayEntry overlay_entry{};
if (!Read32(stream, &overlay_entry.overlay_id) || !Read32(stream, &overlay_entry.target_id)) {
return nullptr;
}
data->overlay_entries_.emplace_back(overlay_entry);
}
// Read raw string pool bytes.
if (!ReadBuffer(stream, &data->string_pool_, data->header_->string_pool_len)) {
return nullptr;
}
return std::move(data);
}
std::string Idmap::CanonicalIdmapPathFor(const std::string& absolute_dir,
const std::string& absolute_apk_path) {
assert(absolute_dir.size() > 0 && absolute_dir[0] == "/");
assert(absolute_apk_path.size() > 0 && absolute_apk_path[0] == "/");
std::string copy(++absolute_apk_path.cbegin(), absolute_apk_path.cend());
replace(copy.begin(), copy.end(), '/', '@');
return absolute_dir + "/" + copy + "@idmap";
}
Result<std::unique_ptr<const Idmap>> Idmap::FromBinaryStream(std::istream& stream) {
SYSTRACE << "Idmap::FromBinaryStream";
std::unique_ptr<Idmap> idmap(new Idmap());
idmap->header_ = IdmapHeader::FromBinaryStream(stream);
if (!idmap->header_) {
return Error("failed to parse idmap header");
}
// idmap version 0x01 does not specify the number of data blocks that follow
// the idmap header; assume exactly one data block
for (int i = 0; i < 1; i++) {
std::unique_ptr<const IdmapData> data = IdmapData::FromBinaryStream(stream);
if (!data) {
return Error("failed to parse data block %d", i);
}
idmap->data_.push_back(std::move(data));
}
return {std::move(idmap)};
}
Result<std::unique_ptr<const IdmapData>> IdmapData::FromResourceMapping(
const ResourceMapping& resource_mapping) {
if (resource_mapping.GetTargetToOverlayMap().empty()) {
return Error("no resources were overlaid");
}
std::unique_ptr<IdmapData> data(new IdmapData());
for (const auto& mappings : resource_mapping.GetTargetToOverlayMap()) {
data->target_entries_.emplace_back(IdmapData::TargetEntry{
mappings.first, mappings.second.data_type, mappings.second.data_value});
}
for (const auto& mappings : resource_mapping.GetOverlayToTargetMap()) {
data->overlay_entries_.emplace_back(IdmapData::OverlayEntry{mappings.first, mappings.second});
}
std::unique_ptr<IdmapData::Header> data_header(new IdmapData::Header());
data_header->target_package_id_ = resource_mapping.GetTargetPackageId();
data_header->overlay_package_id_ = resource_mapping.GetOverlayPackageId();
data_header->target_entry_count = static_cast<uint32_t>(data->target_entries_.size());
data_header->overlay_entry_count = static_cast<uint32_t>(data->overlay_entries_.size());
data_header->string_pool_index_offset = resource_mapping.GetStringPoolOffset();
const auto string_pool_data = resource_mapping.GetStringPoolData();
data_header->string_pool_len = string_pool_data.second;
data->string_pool_ = std::unique_ptr<uint8_t[]>(new uint8_t[data_header->string_pool_len]);
memcpy(data->string_pool_.get(), string_pool_data.first, data_header->string_pool_len);
data->header_ = std::move(data_header);
return {std::move(data)};
}
Result<std::unique_ptr<const Idmap>> Idmap::FromApkAssets(const ApkAssets& target_apk_assets,
const ApkAssets& overlay_apk_assets,
const PolicyBitmask& fulfilled_policies,
bool enforce_overlayable) {
SYSTRACE << "Idmap::FromApkAssets";
const std::string& target_apk_path = target_apk_assets.GetPath();
const std::string& overlay_apk_path = overlay_apk_assets.GetPath();
const std::unique_ptr<const ZipFile> target_zip = ZipFile::Open(target_apk_path);
if (!target_zip) {
return Error("failed to open target as zip");
}
const std::unique_ptr<const ZipFile> overlay_zip = ZipFile::Open(overlay_apk_path);
if (!overlay_zip) {
return Error("failed to open overlay as zip");
}
std::unique_ptr<IdmapHeader> header(new IdmapHeader());
header->magic_ = kIdmapMagic;
header->version_ = kIdmapCurrentVersion;
Result<uint32_t> crc = GetCrc(*target_zip);
if (!crc) {
return Error(crc.GetError(), "failed to get zip CRC for target");
}
header->target_crc_ = *crc;
crc = GetCrc(*overlay_zip);
if (!crc) {
return Error(crc.GetError(), "failed to get zip CRC for overlay");
}
header->overlay_crc_ = *crc;
if (target_apk_path.size() > sizeof(header->target_path_)) {
return Error("target apk path \"%s\" longer than maximum size %zu", target_apk_path.c_str(),
sizeof(header->target_path_));
}
memset(header->target_path_, 0, sizeof(header->target_path_));
memcpy(header->target_path_, target_apk_path.data(), target_apk_path.size());
if (overlay_apk_path.size() > sizeof(header->overlay_path_)) {
return Error("overlay apk path \"%s\" longer than maximum size %zu", overlay_apk_path.c_str(),
sizeof(header->target_path_));
}
memset(header->overlay_path_, 0, sizeof(header->overlay_path_));
memcpy(header->overlay_path_, overlay_apk_path.data(), overlay_apk_path.size());
auto overlay_info = utils::ExtractOverlayManifestInfo(overlay_apk_path);
if (!overlay_info) {
return overlay_info.GetError();
}
LogInfo log_info;
auto resource_mapping =
ResourceMapping::FromApkAssets(target_apk_assets, overlay_apk_assets, *overlay_info,
fulfilled_policies, enforce_overlayable, log_info);
if (!resource_mapping) {
return resource_mapping.GetError();
}
auto idmap_data = IdmapData::FromResourceMapping(*resource_mapping);
if (!idmap_data) {
return idmap_data.GetError();
}
std::unique_ptr<Idmap> idmap(new Idmap());
header->debug_info_ = log_info.GetString();
idmap->header_ = std::move(header);
idmap->data_.push_back(std::move(*idmap_data));
return {std::move(idmap)};
}
void IdmapHeader::accept(Visitor* v) const {
assert(v != nullptr);
v->visit(*this);
}
void IdmapData::Header::accept(Visitor* v) const {
assert(v != nullptr);
v->visit(*this);
}
void IdmapData::accept(Visitor* v) const {
assert(v != nullptr);
header_->accept(v);
v->visit(*this);
}
void Idmap::accept(Visitor* v) const {
assert(v != nullptr);
header_->accept(v);
v->visit(*this);
auto end = data_.cend();
for (auto iter = data_.cbegin(); iter != end; ++iter) {
(*iter)->accept(v);
}
}
} // namespace android::idmap2