ELF/Parser.hpp

/* Copyright 2017 - 2024 R. Thomas
 * Copyright 2017 - 2024 Quarkslab
 *
 * 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 LIEF_ELF_PARSER_H
#define LIEF_ELF_PARSER_H
#include <unordered_map>
 
#include "LIEF/visibility.h"
#include "LIEF/utils.hpp"
 
#include "LIEF/Abstract/Parser.hpp"
#include "LIEF/errors.hpp"
#include "LIEF/ELF/enums.hpp"
 
#include "LIEF/ELF/ParserConfig.hpp"
 
namespace LIEF {
class BinaryStream;
 
namespace OAT {
class Parser;
}
namespace ELF {
 
class Section;
class Binary;
class Segment;
class Symbol;
class Note;
class Relocation;
 
class LIEF_API Parser : public LIEF::Parser {
  friend class OAT::Parser;
  public:
  static constexpr uint32_t NB_MAX_SYMBOLS         = 1000000;
  static constexpr uint32_t DELTA_NB_SYMBOLS       = 3000;
  static constexpr uint32_t NB_MAX_BUCKETS         = NB_MAX_SYMBOLS;
  static constexpr uint32_t NB_MAX_CHAINS          = 1000000;
  static constexpr uint32_t NB_MAX_SEGMENTS        = 10000;
  static constexpr uint32_t NB_MAX_RELOCATIONS     = 3000000;
  static constexpr uint32_t NB_MAX_DYNAMIC_ENTRIES = 1000;
  static constexpr uint32_t NB_MAX_MASKWORD        = 512;
  static constexpr uint32_t MAX_SEGMENT_SIZE       = 3_GB;
 
  enum ELF_TYPE {
    ELF_UNKNOWN,
    ELF32, ELF64
  };
 
  static std::unique_ptr<Binary> parse(const std::string& file,
                                       const ParserConfig& conf = ParserConfig::all());
 
  static std::unique_ptr<Binary> parse(const std::vector<uint8_t>& data,
                                       const ParserConfig& conf = ParserConfig::all());
 
  static std::unique_ptr<Binary> parse(std::unique_ptr<BinaryStream> stream,
                                       const ParserConfig& conf = ParserConfig::all());
 
  Parser& operator=(const Parser&) = delete;
  Parser(const Parser&)            = delete;
 
  protected:
  Parser();
  Parser(std::unique_ptr<BinaryStream> stream, ParserConfig config);
  Parser(const std::string& file, ParserConfig config);
  Parser(const std::vector<uint8_t>& data, ParserConfig config);
 
  ~Parser() override;
 
  ok_error_t init();
 
  bool should_swap() const;
 
  // map, dynamic_symbol.version <----> symbol_version
  // symbol_version comes from symbol_version table
  void link_symbol_version();
 
  ok_error_t link_symbol_section(Symbol& sym);
 
  template<typename ELF_T>
  ok_error_t parse_binary();
 
  template<typename ELF_T>
  ok_error_t parse_header();
 
  template<typename ELF_T>
  ok_error_t parse_sections();
 
  template<typename ELF_T>
  ok_error_t parse_segments();
 
  uint64_t get_dynamic_string_table() const;
 
  result<uint64_t> get_dynamic_string_table_from_segments() const;
 
  uint64_t get_dynamic_string_table_from_sections() const;
 
  template<typename ELF_T>
  result<uint32_t> get_numberof_dynamic_symbols(ParserConfig::DYNSYM_COUNT mtd) const;
 
  template<typename ELF_T>
  result<uint32_t> nb_dynsym_hash() const;
 
  template<typename ELF_T>
  result<uint32_t> nb_dynsym_sysv_hash() const;
 
  template<typename ELF_T>
  result<uint32_t> nb_dynsym_gnu_hash() const;
 
  template<typename ELF_T>
  result<uint32_t> nb_dynsym_section() const;
 
  template<typename ELF_T>
  result<uint32_t> nb_dynsym_relocations() const;
 
  template<typename ELF_T>
  ok_error_t parse_dynamic_entries(uint64_t offset, uint64_t size);
 
  template<typename ELF_T>
  ok_error_t parse_dynamic_symbols(uint64_t offset);
 
  template<typename ELF_T>
  ok_error_t parse_symtab_symbols(uint64_t offset, uint32_t nb_symbols,
                                  const Section& string_section);
 
  template<typename ELF_T, typename REL_T>
  ok_error_t parse_dynamic_relocations(uint64_t relocations_offset, uint64_t size);
 
  template<typename ELF_T, typename REL_T>
  ok_error_t parse_pltgot_relocations(uint64_t offset, uint64_t size);
 
 
  template<typename ELF_T>
  ok_error_t parse_relative_relocations(uint64_t offset, uint64_t size);
 
  template<typename ELF_T>
  ok_error_t parse_packed_relocations(uint64_t offset, uint64_t size);
 
  template<typename ELF_T>
  ok_error_t process_dynamic_table();
 
  template<typename ELF_T, typename REL_T>
  ok_error_t parse_section_relocations(const Section& section);
 
  template<typename ELF_T>
  ok_error_t parse_symbol_version_requirement(uint64_t offset, uint32_t nb_entries);
 
 
  template<typename ELF_T>
  ok_error_t parse_symbol_version_definition(uint64_t offset, uint32_t nb_entries);
 
 
  ok_error_t parse_symbol_version(uint64_t symbol_version_offset);
 
  template<typename ELF_T>
  ok_error_t parse_symbol_gnu_hash(uint64_t offset);
 
  ok_error_t parse_notes(uint64_t offset, uint64_t size);
 
  std::unique_ptr<Note> get_note(uint32_t type, std::string name, std::vector<uint8_t> desc_bytes);
 
  ok_error_t parse_symbol_sysv_hash(uint64_t offset);
 
  ok_error_t parse_overlay();
 
  template<typename ELF_T, typename REL_T>
  uint32_t max_relocation_index(uint64_t relocations_offset, uint64_t size) const;
 
  static bool check_section_in_segment(const Section& section, const Segment& segment);
 
  bool bind_symbol(Relocation& R);
 
  std::unique_ptr<BinaryStream> stream_;
  std::unique_ptr<Binary> binary_;
  ParserConfig config_;
  /*
   * parse_sections() may skip some sections so that
   * binary_->sections_ is not contiguous based on the index of the sections.
   *
   * On the other hand, we need these indexes to bind symbols that
   * reference sections. That's why we have this unordered_map.
   */
  std::unordered_map<size_t, Section*> sections_idx_;
};
 
} // namespace ELF
} // namespace LIEF
#endif