/*
* Copyright (C) 2011 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.
*/
#ifndef ART_RUNTIME_DEX_FILE_VERIFIER_H_
#define ART_RUNTIME_DEX_FILE_VERIFIER_H_
#include <unordered_set>
#include "dex_file.h"
#include "safe_map.h"
namespace art {
class DexFileVerifier {
public:
static bool Verify(const DexFile* dex_file, const uint8_t* begin, size_t size,
const char* location, std::string* error_msg);
const std::string& FailureReason() const {
return failure_reason_;
}
private:
DexFileVerifier(const DexFile* dex_file, const uint8_t* begin, size_t size, const char* location)
: dex_file_(dex_file), begin_(begin), size_(size), location_(location),
header_(&dex_file->GetHeader()), ptr_(nullptr), previous_item_(nullptr) {
}
bool Verify();
bool CheckShortyDescriptorMatch(char shorty_char, const char* descriptor, bool is_return_type);
bool CheckListSize(const void* start, size_t count, size_t element_size, const char* label);
// Check a list. The head is assumed to be at *ptr, and elements to be of size element_size. If
// successful, the ptr will be moved forward the amount covered by the list.
bool CheckList(size_t element_size, const char* label, const uint8_t* *ptr);
// Checks whether the offset is zero (when size is zero) or that the offset falls within the area
// claimed by the file.
bool CheckValidOffsetAndSize(uint32_t offset, uint32_t size, size_t alignment, const char* label);
// Checks whether the size is less than the limit.
bool CheckSizeLimit(uint32_t size, uint32_t limit, const char* label);
bool CheckIndex(uint32_t field, uint32_t limit, const char* label);
bool CheckHeader();
bool CheckMap();
uint32_t ReadUnsignedLittleEndian(uint32_t size);
bool CheckAndGetHandlerOffsets(const DexFile::CodeItem* code_item,
uint32_t* handler_offsets, uint32_t handlers_size);
bool CheckClassDataItemField(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
uint16_t class_type_index,
bool expect_static);
bool CheckClassDataItemMethod(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
uint16_t class_type_index,
uint32_t code_offset,
std::unordered_set<uint32_t>* direct_method_indexes,
bool expect_direct);
bool CheckOrderAndGetClassFlags(bool is_field,
const char* type_descr,
uint32_t curr_index,
uint32_t prev_index,
bool* have_class,
uint16_t* class_type_index,
uint32_t* class_access_flags);
bool CheckPadding(size_t offset, uint32_t aligned_offset);
bool CheckEncodedValue();
bool CheckEncodedArray();
bool CheckEncodedAnnotation();
bool CheckIntraClassDataItem();
// Check all fields of the given type from the given iterator. Load the class data from the first
// field, if necessary (and return it), or use the given values.
template <bool kStatic>
bool CheckIntraClassDataItemFields(ClassDataItemIterator* it,
bool* have_class,
uint16_t* class_type_index,
uint32_t* class_access_flags);
// Check all methods of the given type from the given iterator. Load the class data from the first
// method, if necessary (and return it), or use the given values.
template <bool kDirect>
bool CheckIntraClassDataItemMethods(ClassDataItemIterator* it,
std::unordered_set<uint32_t>* direct_method_indexes,
bool* have_class,
uint16_t* class_type_index,
uint32_t* class_access_flags);
bool CheckIntraCodeItem();
bool CheckIntraStringDataItem();
bool CheckIntraDebugInfoItem();
bool CheckIntraAnnotationItem();
bool CheckIntraAnnotationsDirectoryItem();
bool CheckIntraSectionIterate(size_t offset, uint32_t count, uint16_t type);
bool CheckIntraIdSection(size_t offset, uint32_t count, uint16_t type);
bool CheckIntraDataSection(size_t offset, uint32_t count, uint16_t type);
bool CheckIntraSection();
bool CheckOffsetToTypeMap(size_t offset, uint16_t type);
// Note: as sometimes kDexNoIndex16, being 0xFFFF, is a valid return value, we need an
// additional out parameter to signal any errors loading an index.
uint16_t FindFirstClassDataDefiner(const uint8_t* ptr, bool* success);
uint16_t FindFirstAnnotationsDirectoryDefiner(const uint8_t* ptr, bool* success);
bool CheckInterStringIdItem();
bool CheckInterTypeIdItem();
bool CheckInterProtoIdItem();
bool CheckInterFieldIdItem();
bool CheckInterMethodIdItem();
bool CheckInterClassDefItem();
bool CheckInterAnnotationSetRefList();
bool CheckInterAnnotationSetItem();
bool CheckInterClassDataItem();
bool CheckInterAnnotationsDirectoryItem();
bool CheckInterSectionIterate(size_t offset, uint32_t count, uint16_t type);
bool CheckInterSection();
// Load a string by (type) index. Checks whether the index is in bounds, printing the error if
// not. If there is an error, null is returned.
const char* CheckLoadStringByIdx(uint32_t idx, const char* error_fmt);
const char* CheckLoadStringByTypeIdx(uint32_t type_idx, const char* error_fmt);
// Load a field/method Id by index. Checks whether the index is in bounds, printing the error if
// not. If there is an error, null is returned.
const DexFile::FieldId* CheckLoadFieldId(uint32_t idx, const char* error_fmt);
const DexFile::MethodId* CheckLoadMethodId(uint32_t idx, const char* error_fmt);
void ErrorStringPrintf(const char* fmt, ...)
__attribute__((__format__(__printf__, 2, 3))) COLD_ATTR;
// Retrieve class index and class access flag from the given member. index is the member index,
// which is taken as either a field or a method index (as designated by is_field). The result,
// if the member and declaring class could be found, is stored in class_type_index and
// class_access_flags.
// This is an expensive lookup, as we have to find the class-def by type index, which is a
// linear search. The output values should thus be cached by the caller.
bool FindClassFlags(uint32_t index,
bool is_field,
uint16_t* class_type_index,
uint32_t* class_access_flags);
// Check validity of the given access flags, interpreted for a field in the context of a class
// with the given second access flags.
bool CheckFieldAccessFlags(uint32_t idx,
uint32_t field_access_flags,
uint32_t class_access_flags,
std::string* error_msg);
// Check validity of the given method and access flags, in the context of a class with the given
// second access flags.
bool CheckMethodAccessFlags(uint32_t method_index,
uint32_t method_access_flags,
uint32_t class_access_flags,
bool has_code,
bool expect_direct,
std::string* error_msg);
const DexFile* const dex_file_;
const uint8_t* const begin_;
const size_t size_;
const char* const location_;
const DexFile::Header* const header_;
struct OffsetTypeMapEmptyFn {
// Make a hash map slot empty by making the offset 0. Offset 0 is a valid dex file offset that
// is in the offset of the dex file header. However, we only store data section items in the
// map, and these are after the header.
void MakeEmpty(std::pair<uint32_t, uint16_t>& pair) const {
pair.first = 0u;
}
// Check if a hash map slot is empty.
bool IsEmpty(const std::pair<uint32_t, uint16_t>& pair) const {
return pair.first == 0;
}
};
struct OffsetTypeMapHashCompareFn {
// Hash function for offset.
size_t operator()(const uint32_t key) const {
return key;
}
// std::equal function for offset.
bool operator()(const uint32_t a, const uint32_t b) const {
return a == b;
}
};
// Map from offset to dex file type, HashMap for performance reasons.
AllocationTrackingHashMap<uint32_t,
uint16_t,
OffsetTypeMapEmptyFn,
kAllocatorTagDexFileVerifier,
OffsetTypeMapHashCompareFn,
OffsetTypeMapHashCompareFn> offset_to_type_map_;
const uint8_t* ptr_;
const void* previous_item_;
std::string failure_reason_;
// Set of type ids for which there are ClassDef elements in the dex file.
std::unordered_set<decltype(DexFile::ClassDef::class_idx_)> defined_classes_;
};
} // namespace art
#endif // ART_RUNTIME_DEX_FILE_VERIFIER_H_