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/*
* Copyright (C) 2017 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 "dex_file_loader.h"
#include "android-base/stringprintf.h"
#include "base/stl_util.h"
#include "compact_dex_file.h"
#include "dex_file.h"
#include "dex_file_verifier.h"
#include "standard_dex_file.h"
#include "ziparchive/zip_archive.h"
// system/core/zip_archive definitions.
struct ZipEntry;
typedef void* ZipArchiveHandle;
namespace art {
namespace {
class VectorContainer : public DexFileContainer {
public:
explicit VectorContainer(std::vector<uint8_t>&& vector) : vector_(std::move(vector)) { }
virtual ~VectorContainer() OVERRIDE { }
int GetPermissions() OVERRIDE {
return 0;
}
bool IsReadOnly() OVERRIDE {
return true;
}
bool EnableWrite() OVERRIDE {
return false;
}
bool DisableWrite() OVERRIDE {
return false;
}
private:
std::vector<uint8_t> vector_;
DISALLOW_COPY_AND_ASSIGN(VectorContainer);
};
} // namespace
using android::base::StringPrintf;
class DexZipArchive;
class DexZipEntry {
public:
// Extract this entry to memory.
// Returns null on failure and sets error_msg.
const std::vector<uint8_t> Extract(std::string* error_msg) {
std::vector<uint8_t> map(GetUncompressedLength());
if (map.size() == 0) {
DCHECK(!error_msg->empty());
return map;
}
const int32_t error = ExtractToMemory(handle_, zip_entry_, map.data(), map.size());
if (error) {
*error_msg = std::string(ErrorCodeString(error));
}
return map;
}
virtual ~DexZipEntry() {
delete zip_entry_;
}
uint32_t GetUncompressedLength() {
return zip_entry_->uncompressed_length;
}
uint32_t GetCrc32() {
return zip_entry_->crc32;
}
private:
DexZipEntry(ZipArchiveHandle handle,
::ZipEntry* zip_entry,
const std::string& entry_name)
: handle_(handle), zip_entry_(zip_entry), entry_name_(entry_name) {}
ZipArchiveHandle handle_;
::ZipEntry* const zip_entry_;
std::string const entry_name_;
friend class DexZipArchive;
DISALLOW_COPY_AND_ASSIGN(DexZipEntry);
};
class DexZipArchive {
public:
// return new DexZipArchive instance on success, null on error.
static DexZipArchive* Open(const uint8_t* base, size_t size, std::string* error_msg) {
ZipArchiveHandle handle;
uint8_t* nonconst_base = const_cast<uint8_t*>(base);
const int32_t error = OpenArchiveFromMemory(nonconst_base, size, "ZipArchiveMemory", &handle);
if (error) {
*error_msg = std::string(ErrorCodeString(error));
CloseArchive(handle);
return nullptr;
}
return new DexZipArchive(handle);
}
DexZipEntry* Find(const char* name, std::string* error_msg) const {
DCHECK(name != nullptr);
// Resist the urge to delete the space. <: is a bigraph sequence.
std::unique_ptr< ::ZipEntry> zip_entry(new ::ZipEntry);
const int32_t error = FindEntry(handle_, ZipString(name), zip_entry.get());
if (error) {
*error_msg = std::string(ErrorCodeString(error));
return nullptr;
}
return new DexZipEntry(handle_, zip_entry.release(), name);
}
~DexZipArchive() {
CloseArchive(handle_);
}
private:
explicit DexZipArchive(ZipArchiveHandle handle) : handle_(handle) {}
ZipArchiveHandle handle_;
friend class DexZipEntry;
DISALLOW_COPY_AND_ASSIGN(DexZipArchive);
};
static bool IsZipMagic(uint32_t magic) {
return (('P' == ((magic >> 0) & 0xff)) &&
('K' == ((magic >> 8) & 0xff)));
}
bool DexFileLoader::IsMagicValid(uint32_t magic) {
return IsMagicValid(reinterpret_cast<uint8_t*>(&magic));
}
bool DexFileLoader::IsMagicValid(const uint8_t* magic) {
return StandardDexFile::IsMagicValid(magic) ||
CompactDexFile::IsMagicValid(magic);
}
bool DexFileLoader::IsVersionAndMagicValid(const uint8_t* magic) {
if (StandardDexFile::IsMagicValid(magic)) {
return StandardDexFile::IsVersionValid(magic);
}
if (CompactDexFile::IsMagicValid(magic)) {
return CompactDexFile::IsVersionValid(magic);
}
return false;
}
bool DexFileLoader::IsMultiDexLocation(const char* location) {
return strrchr(location, kMultiDexSeparator) != nullptr;
}
std::string DexFileLoader::GetMultiDexClassesDexName(size_t index) {
return (index == 0) ? "classes.dex" : StringPrintf("classes%zu.dex", index + 1);
}
std::string DexFileLoader::GetMultiDexLocation(size_t index, const char* dex_location) {
return (index == 0)
? dex_location
: StringPrintf("%s%cclasses%zu.dex", dex_location, kMultiDexSeparator, index + 1);
}
std::string DexFileLoader::GetDexCanonicalLocation(const char* dex_location) {
CHECK_NE(dex_location, static_cast<const char*>(nullptr));
std::string base_location = GetBaseLocation(dex_location);
const char* suffix = dex_location + base_location.size();
DCHECK(suffix[0] == 0 || suffix[0] == kMultiDexSeparator);
// Warning: Bionic implementation of realpath() allocates > 12KB on the stack.
// Do not run this code on a small stack, e.g. in signal handler.
UniqueCPtr<const char[]> path(realpath(base_location.c_str(), nullptr));
if (path != nullptr && path.get() != base_location) {
return std::string(path.get()) + suffix;
} else if (suffix[0] == 0) {
return base_location;
} else {
return dex_location;
}
}
// All of the implementations here should be independent of the runtime.
// TODO: implement all the virtual methods.
bool DexFileLoader::GetMultiDexChecksums(
const char* filename ATTRIBUTE_UNUSED,
std::vector<uint32_t>* checksums ATTRIBUTE_UNUSED,
std::string* error_msg,
int zip_fd ATTRIBUTE_UNUSED,
bool* zip_file_only_contains_uncompress_dex ATTRIBUTE_UNUSED) const {
*error_msg = "UNIMPLEMENTED";
return false;
}
std::unique_ptr<const DexFile> DexFileLoader::Open(const uint8_t* base,
size_t size,
const std::string& location,
uint32_t location_checksum,
const OatDexFile* oat_dex_file,
bool verify,
bool verify_checksum,
std::string* error_msg) const {
return OpenCommon(base,
size,
/*data_base*/ nullptr,
/*data_size*/ 0,
location,
location_checksum,
oat_dex_file,
verify,
verify_checksum,
error_msg,
/*container*/ nullptr,
/*verify_result*/ nullptr);
}
std::unique_ptr<const DexFile> DexFileLoader::OpenWithDataSection(
const uint8_t* base,
size_t size,
const uint8_t* data_base,
size_t data_size,
const std::string& location,
uint32_t location_checksum,
const OatDexFile* oat_dex_file,
bool verify,
bool verify_checksum,
std::string* error_msg) const {
return OpenCommon(base,
size,
data_base,
data_size,
location,
location_checksum,
oat_dex_file,
verify,
verify_checksum,
error_msg,
/*container*/ nullptr,
/*verify_result*/ nullptr);
}
bool DexFileLoader::OpenAll(
const uint8_t* base,
size_t size,
const std::string& location,
bool verify,
bool verify_checksum,
std::string* error_msg,
std::vector<std::unique_ptr<const DexFile>>* dex_files) const {
DCHECK(dex_files != nullptr) << "DexFile::Open: out-param is nullptr";
uint32_t magic = *reinterpret_cast<const uint32_t*>(base);
if (IsZipMagic(magic)) {
std::unique_ptr<DexZipArchive> zip_archive(DexZipArchive::Open(base, size, error_msg));
if (zip_archive.get() == nullptr) {
DCHECK(!error_msg->empty());
return false;
}
return OpenAllDexFilesFromZip(*zip_archive.get(),
location,
verify,
verify_checksum,
error_msg,
dex_files);
}
if (IsMagicValid(magic)) {
const DexFile::Header* dex_header = reinterpret_cast<const DexFile::Header*>(base);
std::unique_ptr<const DexFile> dex_file(Open(base,
size,
location,
dex_header->checksum_,
/*oat_dex_file*/ nullptr,
verify,
verify_checksum,
error_msg));
if (dex_file.get() != nullptr) {
dex_files->push_back(std::move(dex_file));
return true;
} else {
return false;
}
}
*error_msg = StringPrintf("Expected valid zip or dex file");
return false;
}
std::unique_ptr<DexFile> DexFileLoader::OpenCommon(const uint8_t* base,
size_t size,
const uint8_t* data_base,
size_t data_size,
const std::string& location,
uint32_t location_checksum,
const OatDexFile* oat_dex_file,
bool verify,
bool verify_checksum,
std::string* error_msg,
std::unique_ptr<DexFileContainer> container,
VerifyResult* verify_result) {
if (verify_result != nullptr) {
*verify_result = VerifyResult::kVerifyNotAttempted;
}
std::unique_ptr<DexFile> dex_file;
if (size >= sizeof(StandardDexFile::Header) && StandardDexFile::IsMagicValid(base)) {
if (data_size != 0) {
CHECK_EQ(base, data_base) << "Unsupported for standard dex";
}
dex_file.reset(new StandardDexFile(base,
size,
location,
location_checksum,
oat_dex_file,
std::move(container)));
} else if (size >= sizeof(CompactDexFile::Header) && CompactDexFile::IsMagicValid(base)) {
if (data_base == nullptr) {
// TODO: Is there a clean way to support both an explicit data section and reading the one
// from the header.
CHECK_EQ(data_size, 0u);
const CompactDexFile::Header* const header = CompactDexFile::Header::At(base);
data_base = base + header->data_off_;
data_size = header->data_size_;
}
dex_file.reset(new CompactDexFile(base,
size,
data_base,
data_size,
location,
location_checksum,
oat_dex_file,
std::move(container)));
// Disable verification for CompactDex input.
verify = false;
} else {
*error_msg = "Invalid or truncated dex file";
}
if (dex_file == nullptr) {
*error_msg = StringPrintf("Failed to open dex file '%s' from memory: %s", location.c_str(),
error_msg->c_str());
return nullptr;
}
if (!dex_file->Init(error_msg)) {
dex_file.reset();
return nullptr;
}
if (verify && !DexFileVerifier::Verify(dex_file.get(),
dex_file->Begin(),
dex_file->Size(),
location.c_str(),
verify_checksum,
error_msg)) {
if (verify_result != nullptr) {
*verify_result = VerifyResult::kVerifyFailed;
}
return nullptr;
}
if (verify_result != nullptr) {
*verify_result = VerifyResult::kVerifySucceeded;
}
return dex_file;
}
std::unique_ptr<const DexFile> DexFileLoader::OpenOneDexFileFromZip(
const DexZipArchive& zip_archive,
const char* entry_name,
const std::string& location,
bool verify,
bool verify_checksum,
std::string* error_msg,
ZipOpenErrorCode* error_code) const {
CHECK(!location.empty());
std::unique_ptr<DexZipEntry> zip_entry(zip_archive.Find(entry_name, error_msg));
if (zip_entry == nullptr) {
*error_code = ZipOpenErrorCode::kEntryNotFound;
return nullptr;
}
if (zip_entry->GetUncompressedLength() == 0) {
*error_msg = StringPrintf("Dex file '%s' has zero length", location.c_str());
*error_code = ZipOpenErrorCode::kDexFileError;
return nullptr;
}
std::vector<uint8_t> map(zip_entry->Extract(error_msg));
if (map.size() == 0) {
*error_msg = StringPrintf("Failed to extract '%s' from '%s': %s", entry_name, location.c_str(),
error_msg->c_str());
*error_code = ZipOpenErrorCode::kExtractToMemoryError;
return nullptr;
}
VerifyResult verify_result;
std::unique_ptr<const DexFile> dex_file = OpenCommon(
map.data(),
map.size(),
/*data_base*/ nullptr,
/*data_size*/ 0u,
location,
zip_entry->GetCrc32(),
/*oat_dex_file*/ nullptr,
verify,
verify_checksum,
error_msg,
std::make_unique<VectorContainer>(std::move(map)),
&verify_result);
if (dex_file == nullptr) {
if (verify_result == VerifyResult::kVerifyNotAttempted) {
*error_code = ZipOpenErrorCode::kDexFileError;
} else {
*error_code = ZipOpenErrorCode::kVerifyError;
}
return nullptr;
}
if (verify_result != VerifyResult::kVerifySucceeded) {
*error_code = ZipOpenErrorCode::kVerifyError;
return nullptr;
}
*error_code = ZipOpenErrorCode::kNoError;
return dex_file;
}
// Technically we do not have a limitation with respect to the number of dex files that can be in a
// multidex APK. However, it's bad practice, as each dex file requires its own tables for symbols
// (types, classes, methods, ...) and dex caches. So warn the user that we open a zip with what
// seems an excessive number.
static constexpr size_t kWarnOnManyDexFilesThreshold = 100;
bool DexFileLoader::OpenAllDexFilesFromZip(
const DexZipArchive& zip_archive,
const std::string& location,
bool verify,
bool verify_checksum,
std::string* error_msg,
std::vector<std::unique_ptr<const DexFile>>* dex_files) const {
DCHECK(dex_files != nullptr) << "DexFile::OpenFromZip: out-param is nullptr";
ZipOpenErrorCode error_code;
std::unique_ptr<const DexFile> dex_file(OpenOneDexFileFromZip(zip_archive,
kClassesDex,
location,
verify,
verify_checksum,
error_msg,
&error_code));
if (dex_file.get() == nullptr) {
return false;
} else {
// Had at least classes.dex.
dex_files->push_back(std::move(dex_file));
// Now try some more.
// We could try to avoid std::string allocations by working on a char array directly. As we
// do not expect a lot of iterations, this seems too involved and brittle.
for (size_t i = 1; ; ++i) {
std::string name = GetMultiDexClassesDexName(i);
std::string fake_location = GetMultiDexLocation(i, location.c_str());
std::unique_ptr<const DexFile> next_dex_file(OpenOneDexFileFromZip(zip_archive,
name.c_str(),
fake_location,
verify,
verify_checksum,
error_msg,
&error_code));
if (next_dex_file.get() == nullptr) {
if (error_code != ZipOpenErrorCode::kEntryNotFound) {
LOG(WARNING) << "Zip open failed: " << *error_msg;
}
break;
} else {
dex_files->push_back(std::move(next_dex_file));
}
if (i == kWarnOnManyDexFilesThreshold) {
LOG(WARNING) << location << " has in excess of " << kWarnOnManyDexFilesThreshold
<< " dex files. Please consider coalescing and shrinking the number to "
" avoid runtime overhead.";
}
if (i == std::numeric_limits<size_t>::max()) {
LOG(ERROR) << "Overflow in number of dex files!";
break;
}
}
return true;
}
}
} // namespace art