libdexfile/external/dex_file_ext.cc - platform/art - Git at Google

 /*
  * 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 "art_api/dex_file_external.h"

 #include <inttypes.h>
 #include <stdint.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>

 #include <cerrno>
 #include <cstring>
 #include <deque>
 #include <map>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>

 #include <android-base/logging.h>
 #include <android-base/macros.h>
 #include <android-base/mapped_file.h>
 #include <android-base/stringprintf.h>

 #include <dex/class_accessor-inl.h>
 #include <dex/code_item_accessors-inl.h>
 #include <dex/dex_file-inl.h>
 #include <dex/dex_file_loader.h>

 extern "C" {

 struct ADexFile_Method {
   ADexFile* adex;
   uint32_t index;
   size_t offset;
   size_t size;
 };

 // Opaque implementation of ADexFile for the C interface.
 struct ADexFile {
   explicit ADexFile(std::unique_ptr<const art::DexFile> dex_file)
       : dex_file_(std::move(dex_file)) {}

   inline bool FindMethod(uint32_t dex_offset, /*out*/ ADexFile_Method* result) {
     uint32_t class_def_index;
     if (GetClassDefIndex(dex_offset, &class_def_index)) {
       art::ClassAccessor accessor(*dex_file_, class_def_index);
       for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
         art::CodeItemInstructionAccessor code = method.GetInstructions();
         if (!code.HasCodeItem()) {
           continue;
         }
         size_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - dex_file_->Begin();
         size_t size = code.InsnsSizeInBytes();
         if (offset <= dex_offset && dex_offset < offset + size) {
           *result = ADexFile_Method {
             .adex = this,
             .index = method.GetIndex(),
             .offset = offset,
             .size = size,
           };
           return true;
         }
       }
     }
     return false;
   }

   void CreateClassCache() {
     // Create binary search table with (end_dex_offset, class_def_index) entries.
     // That is, we don't assume that dex code of given class is consecutive.
     std::deque<std::pair<uint32_t, uint32_t>> cache;
     for (art::ClassAccessor accessor : dex_file_->GetClasses()) {
       for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
         art::CodeItemInstructionAccessor code = method.GetInstructions();
         if (code.HasCodeItem()) {
           int32_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - dex_file_->Begin();
           DCHECK_NE(offset, 0);
           cache.emplace_back(offset + code.InsnsSizeInBytes(), accessor.GetClassDefIndex());
         }
       }
     }
     std::sort(cache.begin(), cache.end());

     // If two consecutive methods belong to same class, we can merge them.
     // This tends to reduce the number of entries (used memory) by 10x.
     size_t num_entries = cache.size();
     if (cache.size() > 1) {
       for (auto it = std::next(cache.begin()); it != cache.end(); it++) {
         if (std::prev(it)->second == it->second) {
           std::prev(it)->first = 0;  // Clear entry with lower end_dex_offset (mark to remove).
           num_entries--;
         }
       }
     }

     // The cache is immutable now. Store it as continuous vector to save space.
     class_cache_.reserve(num_entries);
     auto pred = [](auto it) { return it.first != 0; };  // Entries to copy (not cleared above).
     std::copy_if(cache.begin(), cache.end(), std::back_inserter(class_cache_), pred);
   }

   inline bool GetClassDefIndex(uint32_t dex_offset, uint32_t* class_def_index) {
     if (class_cache_.empty()) {
       CreateClassCache();
     }

     // Binary search in the class cache. First element of the pair is the key.
     auto comp = [](uint32_t value, const auto& it) { return value < it.first; };
     auto it = std::upper_bound(class_cache_.begin(), class_cache_.end(), dex_offset, comp);
     if (it != class_cache_.end()) {
       *class_def_index = it->second;
       return true;
     }
     return false;
   }

   // The underlying ART object.
   std::unique_ptr<const art::DexFile> dex_file_;

   // Binary search table with (end_dex_offset, class_def_index) entries.
   std::vector<std::pair<uint32_t, uint32_t>> class_cache_;

   // Used as short lived temporary when needed. Avoids alloc/free.
   std::string temporary_qualified_name_;
 };

 ADexFile_Error ADexFile_create(const void* _Nonnull address,
                                size_t size,
                                size_t* _Nullable new_size,
                                const char* _Nonnull location,
                                /*out*/ ADexFile* _Nullable * _Nonnull out_dex_file) {
   *out_dex_file = nullptr;

   if (size < sizeof(art::DexFile::Header)) {
     if (new_size != nullptr) {
       *new_size = sizeof(art::DexFile::Header);
     }
     return ADEXFILE_ERROR_NOT_ENOUGH_DATA;
   }

   const art::DexFile::Header* header = reinterpret_cast<const art::DexFile::Header*>(address);
   uint32_t file_size = header->file_size_;
   if (art::CompactDexFile::IsMagicValid(header->magic_)) {
     // Compact dex files store the data section separately so that it can be shared.
     // Therefore we need to extend the read memory range to include it.
     // TODO: This might be wasteful as we might read data in between as well.
     //       In practice, this should be fine, as such sharing only happens on disk.
     uint32_t computed_file_size;
     if (__builtin_add_overflow(header->data_off_, header->data_size_, &computed_file_size)) {
       return ADEXFILE_ERROR_INVALID_HEADER;
     }
     if (computed_file_size > file_size) {
       file_size = computed_file_size;
     }
   } else if (!art::StandardDexFile::IsMagicValid(header->magic_)) {
     return ADEXFILE_ERROR_INVALID_HEADER;
   }

   if (size < file_size) {
     if (new_size != nullptr) {
       *new_size = file_size;
     }
     return ADEXFILE_ERROR_NOT_ENOUGH_DATA;
   }

   std::string loc_str(location);
   art::DexFileLoader loader;
   std::string error_msg;
   std::unique_ptr<const art::DexFile> dex_file = loader.Open(static_cast<const uint8_t*>(address),
                                                              size,
                                                              loc_str,
                                                              header->checksum_,
                                                              /*oat_dex_file=*/nullptr,
                                                              /*verify=*/false,
                                                              /*verify_checksum=*/false,
                                                              &error_msg);
   if (dex_file == nullptr) {
     LOG(ERROR) << "Can not open dex file " << loc_str << ": " << error_msg;
     return ADEXFILE_ERROR_INVALID_DEX;
   }

   *out_dex_file = new ADexFile(std::move(dex_file));
   return ADEXFILE_ERROR_OK;
 }

 void ADexFile_destroy(ADexFile* self) {
   delete self;
 }

 size_t ADexFile_findMethodAtOffset(ADexFile* self,
                                    size_t dex_offset,
                                    ADexFile_MethodCallback* callback,
                                    void* callback_data) {
   const art::DexFile* dex_file = self->dex_file_.get();
   if (!dex_file->IsInDataSection(dex_file->Begin() + dex_offset)) {
     return 0;  // The DEX offset is not within the bytecode of this dex file.
   }

   if (dex_file->IsCompactDexFile()) {
     // The data section of compact dex files might be shared.
     // Check the subrange unique to this compact dex.
     const art::CompactDexFile::Header& cdex_header =
         dex_file->AsCompactDexFile()->GetHeader();
     uint32_t begin = cdex_header.data_off_ + cdex_header.OwnedDataBegin();
     uint32_t end = cdex_header.data_off_ + cdex_header.OwnedDataEnd();
     if (dex_offset < begin || dex_offset >= end) {
       return 0;  // The DEX offset is not within the bytecode of this dex file.
     }
   }

   ADexFile_Method info;
   if (!self->FindMethod(dex_offset, &info)) {
     return 0;
   }

   callback(callback_data, &info);
   return 1;
 }

 size_t ADexFile_forEachMethod(ADexFile* self,
                               ADexFile_MethodCallback* callback,
                               void* callback_data) {
   size_t count = 0;
   for (art::ClassAccessor accessor : self->dex_file_->GetClasses()) {
     for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
       art::CodeItemInstructionAccessor code = method.GetInstructions();
       if (code.HasCodeItem()) {
         size_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - self->dex_file_->Begin();
         ADexFile_Method info {
           .adex = self,
           .index = method.GetIndex(),
           .offset = offset,
           .size = code.InsnsSizeInBytes(),
         };
         callback(callback_data, &info);
         count++;
       }
     }
   }
   return count;
 }

 size_t ADexFile_Method_getCodeOffset(const ADexFile_Method* self,
                                      size_t* out_size) {
   if (out_size != nullptr) {
     *out_size = self->size;
   }
   return self->offset;
 }

 const char* ADexFile_Method_getName(const ADexFile_Method* self,
                                     size_t* out_size) {
   const char* name = self->adex->dex_file_->GetMethodName(self->index);
   if (out_size != nullptr) {
     *out_size = strlen(name);
   }
   return name;
 }

 const char* ADexFile_Method_getQualifiedName(const ADexFile_Method* self,
                                              int with_params,
                                              size_t* out_size) {
   std::string& temp = self->adex->temporary_qualified_name_;
   temp.clear();
   self->adex->dex_file_->AppendPrettyMethod(self->index, with_params, &temp);
   if (out_size != nullptr) {
     *out_size = temp.size();
   }
   return temp.data();
 }

 const char* ADexFile_Method_getClassDescriptor(const ADexFile_Method* self,
                                                size_t* out_size) {
   const art::dex::MethodId& method_id = self->adex->dex_file_->GetMethodId(self->index);
   const char* name = self->adex->dex_file_->GetMethodDeclaringClassDescriptor(method_id);
   if (out_size != nullptr) {
     *out_size = strlen(name);
   }
   return name;
 }

 const char* ADexFile_Error_toString(ADexFile_Error self) {
   switch (self) {
     case ADEXFILE_ERROR_OK: return "Ok";
     case ADEXFILE_ERROR_INVALID_DEX: return "Dex file is invalid.";
     case ADEXFILE_ERROR_NOT_ENOUGH_DATA: return "Not enough data. Incomplete dex file.";
     case ADEXFILE_ERROR_INVALID_HEADER: return "Invalid dex file header.";
   }
   return nullptr;
 }

 }  // extern "C"
	/*
	* 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 "art_api/dex_file_external.h"

	#include <inttypes.h>
	#include <stdint.h>
	#include <sys/stat.h>
	#include <sys/types.h>
	#include <unistd.h>

	#include <cerrno>
	#include <cstring>
	#include <deque>
	#include <map>
	#include <memory>
	#include <string>
	#include <utility>
	#include <vector>

	#include <android-base/logging.h>
	#include <android-base/macros.h>
	#include <android-base/mapped_file.h>
	#include <android-base/stringprintf.h>

	#include <dex/class_accessor-inl.h>
	#include <dex/code_item_accessors-inl.h>
	#include <dex/dex_file-inl.h>
	#include <dex/dex_file_loader.h>

	extern "C" {

	struct ADexFile_Method {
	ADexFile* adex;
	uint32_t index;
	size_t offset;
	size_t size;
	};

	// Opaque implementation of ADexFile for the C interface.
	struct ADexFile {
	explicit ADexFile(std::unique_ptr<const art::DexFile> dex_file)
	: dex_file_(std::move(dex_file)) {}

	inline bool FindMethod(uint32_t dex_offset, /out/ ADexFile_Method* result) {
	uint32_t class_def_index;
	if (GetClassDefIndex(dex_offset, &class_def_index)) {
	art::ClassAccessor accessor(*dex_file_, class_def_index);
	for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
	art::CodeItemInstructionAccessor code = method.GetInstructions();
	if (!code.HasCodeItem()) {
	continue;
	}
	size_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - dex_file_->Begin();
	size_t size = code.InsnsSizeInBytes();
	if (offset <= dex_offset && dex_offset < offset + size) {
	*result = ADexFile_Method {
	.adex = this,
	.index = method.GetIndex(),
	.offset = offset,
	.size = size,
	};
	return true;
	}
	}
	}
	return false;
	}

	void CreateClassCache() {
	// Create binary search table with (end_dex_offset, class_def_index) entries.
	// That is, we don't assume that dex code of given class is consecutive.
	std::deque<std::pair<uint32_t, uint32_t>> cache;
	for (art::ClassAccessor accessor : dex_file_->GetClasses()) {
	for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
	art::CodeItemInstructionAccessor code = method.GetInstructions();
	if (code.HasCodeItem()) {
	int32_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - dex_file_->Begin();
	DCHECK_NE(offset, 0);
	cache.emplace_back(offset + code.InsnsSizeInBytes(), accessor.GetClassDefIndex());
	}
	}
	}
	std::sort(cache.begin(), cache.end());

	// If two consecutive methods belong to same class, we can merge them.
	// This tends to reduce the number of entries (used memory) by 10x.
	size_t num_entries = cache.size();
	if (cache.size() > 1) {
	for (auto it = std::next(cache.begin()); it != cache.end(); it++) {
	if (std::prev(it)->second == it->second) {
	std::prev(it)->first = 0; // Clear entry with lower end_dex_offset (mark to remove).
	num_entries--;
	}
	}
	}

	// The cache is immutable now. Store it as continuous vector to save space.
	class_cache_.reserve(num_entries);
	auto pred = [](auto it) { return it.first != 0; }; // Entries to copy (not cleared above).
	std::copy_if(cache.begin(), cache.end(), std::back_inserter(class_cache_), pred);
	}

	inline bool GetClassDefIndex(uint32_t dex_offset, uint32_t* class_def_index) {
	if (class_cache_.empty()) {
	CreateClassCache();
	}

	// Binary search in the class cache. First element of the pair is the key.
	auto comp = [](uint32_t value, const auto& it) { return value < it.first; };
	auto it = std::upper_bound(class_cache_.begin(), class_cache_.end(), dex_offset, comp);
	if (it != class_cache_.end()) {
	*class_def_index = it->second;
	return true;
	}
	return false;
	}

	// The underlying ART object.
	std::unique_ptr<const art::DexFile> dex_file_;

	// Binary search table with (end_dex_offset, class_def_index) entries.
	std::vector<std::pair<uint32_t, uint32_t>> class_cache_;

	// Used as short lived temporary when needed. Avoids alloc/free.
	std::string temporary_qualified_name_;
	};

	ADexFile_Error ADexFile_create(const void* _Nonnull address,
	size_t size,
	size_t* _Nullable new_size,
	const char* _Nonnull location,
	/out/ ADexFile* _Nullable * _Nonnull out_dex_file) {
	*out_dex_file = nullptr;

	if (size < sizeof(art::DexFile::Header)) {
	if (new_size != nullptr) {
	*new_size = sizeof(art::DexFile::Header);
	}
	return ADEXFILE_ERROR_NOT_ENOUGH_DATA;
	}

	const art::DexFile::Header* header = reinterpret_cast<const art::DexFile::Header*>(address);
	uint32_t file_size = header->file_size_;
	if (art::CompactDexFile::IsMagicValid(header->magic_)) {
	// Compact dex files store the data section separately so that it can be shared.
	// Therefore we need to extend the read memory range to include it.
	// TODO: This might be wasteful as we might read data in between as well.
	// In practice, this should be fine, as such sharing only happens on disk.
	uint32_t computed_file_size;
	if (__builtin_add_overflow(header->data_off_, header->data_size_, &computed_file_size)) {
	return ADEXFILE_ERROR_INVALID_HEADER;
	}
	if (computed_file_size > file_size) {
	file_size = computed_file_size;
	}
	} else if (!art::StandardDexFile::IsMagicValid(header->magic_)) {
	return ADEXFILE_ERROR_INVALID_HEADER;
	}

	if (size < file_size) {
	if (new_size != nullptr) {
	*new_size = file_size;
	}
	return ADEXFILE_ERROR_NOT_ENOUGH_DATA;
	}

	std::string loc_str(location);
	art::DexFileLoader loader;
	std::string error_msg;
	std::unique_ptr<const art::DexFile> dex_file = loader.Open(static_cast<const uint8_t*>(address),
	size,
	loc_str,
	header->checksum_,
	/oat_dex_file=/nullptr,
	/verify=/false,
	/verify_checksum=/false,
	&error_msg);
	if (dex_file == nullptr) {
	LOG(ERROR) << "Can not open dex file " << loc_str << ": " << error_msg;
	return ADEXFILE_ERROR_INVALID_DEX;
	}

	*out_dex_file = new ADexFile(std::move(dex_file));
	return ADEXFILE_ERROR_OK;
	}

	void ADexFile_destroy(ADexFile* self) {
	delete self;
	}

	size_t ADexFile_findMethodAtOffset(ADexFile* self,
	size_t dex_offset,
	ADexFile_MethodCallback* callback,
	void* callback_data) {
	const art::DexFile* dex_file = self->dex_file_.get();
	if (!dex_file->IsInDataSection(dex_file->Begin() + dex_offset)) {
	return 0; // The DEX offset is not within the bytecode of this dex file.
	}

	if (dex_file->IsCompactDexFile()) {
	// The data section of compact dex files might be shared.
	// Check the subrange unique to this compact dex.
	const art::CompactDexFile::Header& cdex_header =
	dex_file->AsCompactDexFile()->GetHeader();
	uint32_t begin = cdex_header.data_off_ + cdex_header.OwnedDataBegin();
	uint32_t end = cdex_header.data_off_ + cdex_header.OwnedDataEnd();
	if (dex_offset < begin \|\| dex_offset >= end) {
	return 0; // The DEX offset is not within the bytecode of this dex file.
	}
	}

	ADexFile_Method info;
	if (!self->FindMethod(dex_offset, &info)) {
	return 0;
	}

	callback(callback_data, &info);
	return 1;
	}

	size_t ADexFile_forEachMethod(ADexFile* self,
	ADexFile_MethodCallback* callback,
	void* callback_data) {
	size_t count = 0;
	for (art::ClassAccessor accessor : self->dex_file_->GetClasses()) {
	for (const art::ClassAccessor::Method& method : accessor.GetMethods()) {
	art::CodeItemInstructionAccessor code = method.GetInstructions();
	if (code.HasCodeItem()) {
	size_t offset = reinterpret_cast<const uint8_t*>(code.Insns()) - self->dex_file_->Begin();
	ADexFile_Method info {
	.adex = self,
	.index = method.GetIndex(),
	.offset = offset,
	.size = code.InsnsSizeInBytes(),
	};
	callback(callback_data, &info);
	count++;
	}
	}
	}
	return count;
	}

	size_t ADexFile_Method_getCodeOffset(const ADexFile_Method* self,
	size_t* out_size) {
	if (out_size != nullptr) {
	*out_size = self->size;
	}
	return self->offset;
	}

	const char* ADexFile_Method_getName(const ADexFile_Method* self,
	size_t* out_size) {
	const char* name = self->adex->dex_file_->GetMethodName(self->index);
	if (out_size != nullptr) {
	*out_size = strlen(name);
	}
	return name;
	}

	const char* ADexFile_Method_getQualifiedName(const ADexFile_Method* self,
	int with_params,
	size_t* out_size) {
	std::string& temp = self->adex->temporary_qualified_name_;
	temp.clear();
	self->adex->dex_file_->AppendPrettyMethod(self->index, with_params, &temp);
	if (out_size != nullptr) {
	*out_size = temp.size();
	}
	return temp.data();
	}

	const char* ADexFile_Method_getClassDescriptor(const ADexFile_Method* self,
	size_t* out_size) {
	const art::dex::MethodId& method_id = self->adex->dex_file_->GetMethodId(self->index);
	const char* name = self->adex->dex_file_->GetMethodDeclaringClassDescriptor(method_id);
	if (out_size != nullptr) {
	*out_size = strlen(name);
	}
	return name;
	}

	const char* ADexFile_Error_toString(ADexFile_Error self) {
	switch (self) {
	case ADEXFILE_ERROR_OK: return "Ok";
	case ADEXFILE_ERROR_INVALID_DEX: return "Dex file is invalid.";
	case ADEXFILE_ERROR_NOT_ENOUGH_DATA: return "Not enough data. Incomplete dex file.";
	case ADEXFILE_ERROR_INVALID_HEADER: return "Invalid dex file header.";
	}
	return nullptr;
	}

	} // extern "C"