src/monitor/elf/SymbolParser.cpp

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