monitor/src/elf/SymbolParser.cpp

   1 #include <iostream>
   2 #include <cstring>
   3
   4 #include "SymbolParser.h"
   5 #include "Parser.h"
   6 #include "Initializer.h"
   7
   8 namespace ELF {
   9
  10 SymbolParser::SymbolParser(Parser *elf_parser) : elf_parser(elf_parser) {
  11     StorageManager *storage_manager = Initializer::get_instance()->get_storage_manager();
  12     std::cout << std::hex;
  13     /* Start off with the static symbols . . . */
  14     Section *symbol_table = elf_parser->get_section(".symtab");
  15     if(symbol_table) { /* Only try to parse the symbols if the .symtab section exists */
  16         Block *symbol_block = symbol_table->get_content();
  17         while(symbol_block->get_size()) {
  18             Elf64_Sym sym;
  19             symbol_block->read(&sym, sizeof(sym));
  20
  21             char *name = (char *)(elf_parser->get_section(".strtab")->get_content()->get_data() + sym.st_name);
  22             if(sym.st_value) symbol_vector.push_back(storage_manager->new_symbol(name, sym.st_value, sym.st_size)->get_storage_offset());
  23         }
  24     }
  25     symbol_table = elf_parser->get_section(".rela.plt");
  26     if(symbol_table) {
  27         symbol_table->read_content();
  28         /*Block *address_table = elf_parser->get_section(".rela.plt")->get_content();
  29         while(address_table->get_size()) {
  30             Elf64_Rela rela;
  31             address_table->read(&rela, sizeof(rela));
  32             Word symbol = ELF64_R_SYM(rela.r_info);
  33             if(symbol > dynamic_offsets.size()) dynamic_offsets.resize(symbol * 2);
  34             dynamic_offsets[symbol] = rela.r_offset;
  35             std::cout << "Dynamic offset parsed:" << std::hex << std::endl;
  36             std::cout << "\tsymbol: " << symbol << std::endl;
  37             std::cout << "\tr_offset: " << rela.r_offset << std::endl;
  38             std::cout << "\tr_addend: " << rela.r_addend << std::endl;
  39         }*/
  40
  41         Block *symbol_block;
  42         /* Now for the dynamic symbols. Otherwise known as the tricky ones. */
  43         symbol_block = elf_parser->get_section(".dynsym")->get_content();
  44         std::size_t index = 0;
  45         while(symbol_block->get_size()) {
  46             Elf64_Sym sym;
  47             symbol_block->read(&sym, sizeof(sym));
  48
  49             char *name = (char *)&elf_parser->get_section(".dynstr")->get_content()->get_data()[sym.st_name];
  50             /*if(!std::strcmp(name, "malloc")) {
  51                 std::cout << "malloc symbol:" << std::endl;
  52                 std::cout << "\tdynamic_offset is: " << dynamic_offsets[index] << std::endl;
  53                 std::cout << "\tvalue is " << sym.st_value << std::endl;
  54             }*/
  55             /*std::cout << "Dynamic symbol: name is \"" << name << "\", address is " << sym.st_value << std::endl;
  56             std::cout << "Dynamic offset for this symbol is: " << dynamic_offsets[index] << std::endl;*/
  57             if(sym.st_name) symbol_vector.push_back(storage_manager->new_symbol(name, sym.st_value/* + dynamic_offsets[index]*/, sym.st_size)->get_storage_offset());
  58             index ++;
  59         }
  60     }
  61     std::cout << std::dec;
  62 }
  63
  64 SymbolParser::~SymbolParser() {
  65     for(symbol_vector_t::iterator i = symbol_vector.begin(); i != symbol_vector.end(); i ++) {
  66         Initializer::get_instance()->get_storage_manager()->get_symbol(*i)->~Symbol();
  67     }
  68 }
  69
  70 Symbol *SymbolParser::get_symbol(std::string name) const {
  71     StorageManager *storage_manager = Initializer::get_instance()->get_storage_manager();
  72     for(symbol_vector_t::const_iterator i = symbol_vector.begin(); i != symbol_vector.end(); i ++) {
  73         if(storage_manager->get_symbol(*i)->get_symbol_name() == name) return storage_manager->get_symbol(*i);
  74     }
  75     return NULL;
  76 }
  77
  78 void SymbolParser::dump_symbols() const {
  79     std::cout << "Symbol dump: \n";
  80     for(symbol_vector_t::const_iterator i = symbol_vector.begin(); i != symbol_vector.end(); i ++) {
  81         /*std::cout << "\tSymbol: name is \"" << (*i)->get_symbol_name() << "\", address is 0x" << std::hex << (*i)->get_address() << std::dec << std::endl;*/
  82     }
  83 }
  84
  85 } // namespace ELF