/*
* 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 "art_dex_file_loader.h"
#include <sys/mman.h> // For the PROT_* and MAP_* constants.
#include <sys/stat.h>
#include "android-base/stringprintf.h"
#include "base/file_magic.h"
#include "base/file_utils.h"
#include "base/stl_util.h"
#include "base/systrace.h"
#include "base/unix_file/fd_file.h"
#include "dex/compact_dex_file.h"
#include "dex/dex_file.h"
#include "dex/dex_file_verifier.h"
#include "dex/standard_dex_file.h"
#include "zip_archive.h"
namespace art {
namespace {
class MemMapContainer : public DexFileContainer {
public:
explicit MemMapContainer(std::unique_ptr<MemMap>&& mem_map) : mem_map_(std::move(mem_map)) { }
virtual ~MemMapContainer() OVERRIDE { }
int GetPermissions() OVERRIDE {
if (mem_map_.get() == nullptr) {
return 0;
} else {
return mem_map_->GetProtect();
}
}
bool IsReadOnly() OVERRIDE {
return GetPermissions() == PROT_READ;
}
bool EnableWrite() OVERRIDE {
CHECK(IsReadOnly());
if (mem_map_.get() == nullptr) {
return false;
} else {
return mem_map_->Protect(PROT_READ | PROT_WRITE);
}
}
bool DisableWrite() OVERRIDE {
CHECK(!IsReadOnly());
if (mem_map_.get() == nullptr) {
return false;
} else {
return mem_map_->Protect(PROT_READ);
}
}
private:
std::unique_ptr<MemMap> mem_map_;
DISALLOW_COPY_AND_ASSIGN(MemMapContainer);
};
} // namespace
using android::base::StringPrintf;
static constexpr OatDexFile* kNoOatDexFile = nullptr;
bool ArtDexFileLoader::GetMultiDexChecksums(const char* filename,
std::vector<uint32_t>* checksums,
std::string* error_msg,
int zip_fd,
bool* zip_file_only_contains_uncompressed_dex) const {
CHECK(checksums != nullptr);
uint32_t magic;
File fd;
if (zip_fd != -1) {
if (ReadMagicAndReset(zip_fd, &magic, error_msg)) {
fd = File(zip_fd, false /* check_usage */);
}
} else {
fd = OpenAndReadMagic(filename, &magic, error_msg);
}
if (fd.Fd() == -1) {
DCHECK(!error_msg->empty());
return false;
}
if (IsZipMagic(magic)) {
std::unique_ptr<ZipArchive> zip_archive(
ZipArchive::OpenFromFd(fd.Release(), filename, error_msg));
if (zip_archive.get() == nullptr) {
*error_msg = StringPrintf("Failed to open zip archive '%s' (error msg: %s)", filename,
error_msg->c_str());
return false;
}
uint32_t i = 0;
std::string zip_entry_name = GetMultiDexClassesDexName(i++);
std::unique_ptr<ZipEntry> zip_entry(zip_archive->Find(zip_entry_name.c_str(), error_msg));
if (zip_entry.get() == nullptr) {
*error_msg = StringPrintf("Zip archive '%s' doesn't contain %s (error msg: %s)", filename,
zip_entry_name.c_str(), error_msg->c_str());
return false;
}
if (zip_file_only_contains_uncompressed_dex != nullptr) {
// Start by assuming everything is uncompressed.
*zip_file_only_contains_uncompressed_dex = true;
}
do {
if (zip_file_only_contains_uncompressed_dex != nullptr) {
if (!(zip_entry->IsUncompressed() && zip_entry->IsAlignedToDexHeader())) {
*zip_file_only_contains_uncompressed_dex = false;
}
}
checksums->push_back(zip_entry->GetCrc32());
zip_entry_name = GetMultiDexClassesDexName(i++);
zip_entry.reset(zip_archive->Find(zip_entry_name.c_str(), error_msg));
} while (zip_entry.get() != nullptr);
return true;
}
if (IsMagicValid(magic)) {
std::unique_ptr<const DexFile> dex_file(OpenFile(fd.Release(),
filename,
/* verify */ false,
/* verify_checksum */ false,
/* mmap_shared */ false,
error_msg));
if (dex_file == nullptr) {
return false;
}
checksums->push_back(dex_file->GetHeader().checksum_);
return true;
}
*error_msg = StringPrintf("Expected valid zip or dex file: '%s'", filename);
return false;
}
std::unique_ptr<const DexFile> ArtDexFileLoader::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 {
ScopedTrace trace(std::string("Open dex file from RAM ") + location);
return OpenCommon(base,
size,
/*data_base*/ nullptr,
/*data_size*/ 0u,
location,
location_checksum,
oat_dex_file,
verify,
verify_checksum,
error_msg,
/*container*/ nullptr,
/*verify_result*/ nullptr);
}
std::unique_ptr<const DexFile> ArtDexFileLoader::Open(const std::string& location,
uint32_t location_checksum,
std::unique_ptr<MemMap> map,
bool verify,
bool verify_checksum,
std::string* error_msg) const {
ScopedTrace trace(std::string("Open dex file from mapped-memory ") + location);
CHECK(map.get() != nullptr);
if (map->Size() < sizeof(DexFile::Header)) {
*error_msg = StringPrintf(
"DexFile: failed to open dex file '%s' that is too short to have a header",
location.c_str());
return nullptr;
}
std::unique_ptr<DexFile> dex_file = OpenCommon(map->Begin(),
map->Size(),
/*data_base*/ nullptr,
/*data_size*/ 0u,
location,
location_checksum,
kNoOatDexFile,
verify,
verify_checksum,
error_msg,
std::make_unique<MemMapContainer>(std::move(map)),
/*verify_result*/ nullptr);
// Opening CompactDex is only supported from vdex files.
if (dex_file != nullptr && dex_file->IsCompactDexFile()) {
*error_msg = StringPrintf("Opening CompactDex file '%s' is only supported from vdex files",
location.c_str());
return nullptr;
}
return dex_file;
}
bool ArtDexFileLoader::Open(const char* filename,
const std::string& location,
bool verify,
bool verify_checksum,
std::string* error_msg,
std::vector<std::unique_ptr<const DexFile>>* dex_files) const {
ScopedTrace trace(std::string("Open dex file ") + std::string(location));
DCHECK(dex_files != nullptr) << "DexFile::Open: out-param is nullptr";
uint32_t magic;
File fd = OpenAndReadMagic(filename, &magic, error_msg);
if (fd.Fd() == -1) {
DCHECK(!error_msg->empty());
return false;
}
if (IsZipMagic(magic)) {
return OpenZip(fd.Release(), location, verify, verify_checksum, error_msg, dex_files);
}
if (IsMagicValid(magic)) {
std::unique_ptr<const DexFile> dex_file(OpenFile(fd.Release(),
location,
verify,
verify_checksum,
/* mmap_shared */ false,
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: '%s'", filename);
return false;
}
std::unique_ptr<const DexFile> ArtDexFileLoader::OpenDex(int fd,
const std::string& location,
bool verify,
bool verify_checksum,
bool mmap_shared,
std::string* error_msg) const {
ScopedTrace trace("Open dex file " + std::string(location));
return OpenFile(fd, location, verify, verify_checksum, mmap_shared, error_msg);
}
bool ArtDexFileLoader::OpenZip(int fd,
const std::string& location,
bool verify,
bool verify_checksum,
std::string* error_msg,
std::vector<std::unique_ptr<const DexFile>>* dex_files) const {
ScopedTrace trace("Dex file open Zip " + std::string(location));
DCHECK(dex_files != nullptr) << "DexFile::OpenZip: out-param is nullptr";
std::unique_ptr<ZipArchive> zip_archive(ZipArchive::OpenFromFd(fd, location.c_str(), error_msg));
if (zip_archive.get() == nullptr) {
DCHECK(!error_msg->empty());
return false;
}
return OpenAllDexFilesFromZip(
*zip_archive, location, verify, verify_checksum, error_msg, dex_files);
}
std::unique_ptr<const DexFile> ArtDexFileLoader::OpenFile(int fd,
const std::string& location,
bool verify,
bool verify_checksum,
bool mmap_shared,
std::string* error_msg) const {
ScopedTrace trace(std::string("Open dex file ") + std::string(location));
CHECK(!location.empty());
std::unique_ptr<MemMap> map;
{
File delayed_close(fd, /* check_usage */ false);
struct stat sbuf;
memset(&sbuf, 0, sizeof(sbuf));
if (fstat(fd, &sbuf) == -1) {
*error_msg = StringPrintf("DexFile: fstat '%s' failed: %s", location.c_str(),
strerror(errno));
return nullptr;
}
if (S_ISDIR(sbuf.st_mode)) {
*error_msg = StringPrintf("Attempt to mmap directory '%s'", location.c_str());
return nullptr;
}
size_t length = sbuf.st_size;
map.reset(MemMap::MapFile(length,
PROT_READ,
mmap_shared ? MAP_SHARED : MAP_PRIVATE,
fd,
0,
/*low_4gb*/false,
location.c_str(),
error_msg));
if (map == nullptr) {
DCHECK(!error_msg->empty());
return nullptr;
}
}
if (map->Size() < sizeof(DexFile::Header)) {
*error_msg = StringPrintf(
"DexFile: failed to open dex file '%s' that is too short to have a header",
location.c_str());
return nullptr;
}
const DexFile::Header* dex_header = reinterpret_cast<const DexFile::Header*>(map->Begin());
std::unique_ptr<DexFile> dex_file = OpenCommon(map->Begin(),
map->Size(),
/*data_base*/ nullptr,
/*data_size*/ 0u,
location,
dex_header->checksum_,
kNoOatDexFile,
verify,
verify_checksum,
error_msg,
std::make_unique<MemMapContainer>(std::move(map)),
/*verify_result*/ nullptr);
// Opening CompactDex is only supported from vdex files.
if (dex_file != nullptr && dex_file->IsCompactDexFile()) {
*error_msg = StringPrintf("Opening CompactDex file '%s' is only supported from vdex files",
location.c_str());
return nullptr;
}
return dex_file;
}
std::unique_ptr<const DexFile> ArtDexFileLoader::OpenOneDexFileFromZip(
const ZipArchive& zip_archive,
const char* entry_name,
const std::string& location,
bool verify,
bool verify_checksum,
std::string* error_msg,
ZipOpenErrorCode* error_code) const {
ScopedTrace trace("Dex file open from Zip Archive " + std::string(location));
CHECK(!location.empty());
std::unique_ptr<ZipEntry> 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::unique_ptr<MemMap> map;
if (zip_entry->IsUncompressed()) {
if (!zip_entry->IsAlignedTo(alignof(DexFile::Header))) {
// Do not mmap unaligned ZIP entries because
// doing so would fail dex verification which requires 4 byte alignment.
LOG(WARNING) << "Can't mmap dex file " << location << "!" << entry_name << " directly; "
<< "please zipalign to " << alignof(DexFile::Header) << " bytes. "
<< "Falling back to extracting file.";
} else {
// Map uncompressed files within zip as file-backed to avoid a dirty copy.
map.reset(zip_entry->MapDirectlyFromFile(location.c_str(), /*out*/error_msg));
if (map == nullptr) {
LOG(WARNING) << "Can't mmap dex file " << location << "!" << entry_name << " directly; "
<< "is your ZIP file corrupted? Falling back to extraction.";
// Try again with Extraction which still has a chance of recovery.
}
}
}
if (map == nullptr) {
// Default path for compressed ZIP entries,
// and fallback for stored ZIP entries.
map.reset(zip_entry->ExtractToMemMap(location.c_str(), entry_name, error_msg));
}
if (map == nullptr) {
*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<DexFile> dex_file = OpenCommon(map->Begin(),
map->Size(),
/*data_base*/ nullptr,
/*data_size*/ 0u,
location,
zip_entry->GetCrc32(),
kNoOatDexFile,
verify,
verify_checksum,
error_msg,
std::make_unique<MemMapContainer>(std::move(map)),
&verify_result);
if (dex_file != nullptr && dex_file->IsCompactDexFile()) {
*error_msg = StringPrintf("Opening CompactDex file '%s' is only supported from vdex files",
location.c_str());
return nullptr;
}
if (dex_file == nullptr) {
if (verify_result == VerifyResult::kVerifyNotAttempted) {
*error_code = ZipOpenErrorCode::kDexFileError;
} else {
*error_code = ZipOpenErrorCode::kVerifyError;
}
return nullptr;
}
if (!dex_file->DisableWrite()) {
*error_msg = StringPrintf("Failed to make dex file '%s' read only", location.c_str());
*error_code = ZipOpenErrorCode::kMakeReadOnlyError;
return nullptr;
}
CHECK(dex_file->IsReadOnly()) << location;
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 ArtDexFileLoader::OpenAllDexFilesFromZip(
const ZipArchive& 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 {
ScopedTrace trace("Dex file open from Zip " + std::string(location));
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;
}
}
std::unique_ptr<DexFile> ArtDexFileLoader::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) {
std::unique_ptr<DexFile> dex_file = DexFileLoader::OpenCommon(base,
size,
data_base,
data_size,
location,
location_checksum,
oat_dex_file,
verify,
verify_checksum,
error_msg,
std::move(container),
verify_result);
// Check if this dex file is located in the framework directory.
// If it is, set a flag on the dex file. This is used by hidden API
// policy decision logic.
// Location can contain multidex suffix, so fetch its canonical version. Note
// that this will call `realpath`.
std::string path = DexFileLoader::GetDexCanonicalLocation(location.c_str());
if (dex_file != nullptr && LocationIsOnSystemFramework(path.c_str())) {
dex_file->SetIsPlatformDexFile();
}
return dex_file;
}
} // namespace art