src/monitor/elf/SymbolParser.cpp

   1 #include <iostream>
   2 #include <cstring>
   3
   4 #include "SymbolParser.h"
   5 #include "Parser.h"
   6
   7 namespace Aesalon {
   8 namespace Monitor {
   9 namespace ELF {
  10
  11 SymbolParser::SymbolParser(Misc::SmartPointer<Parser> elf_parser) : elf_parser(elf_parser) {
  12     std::cout << std::hex;
  13     /* Start off with the static symbols . . . */
  14     Misc::SmartPointer<Section> symbol_table = elf_parser->get_section(".symtab");
  15     if(symbol_table.is_valid()) { /* Only try to parse the symbols if the .symtab section exists */
  16         Misc::SmartPointer<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(new Symbol(name, sym.st_value, sym.st_size));
  23         }
  24     }
  25     symbol_table = elf_parser->get_section(".rela.plt");
  26     if(symbol_table.is_valid()) {
  27         symbol_table->read_content();
  28         /*Misc::SmartPointer<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         Misc::SmartPointer<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(new Symbol(name, sym.st_value/* + dynamic_offsets[index]*/, sym.st_size));
  58             index ++;
  59         }
  60     }
  61     std::cout << std::dec;
  62 }
  63
  64 Misc::SmartPointer<Symbol> SymbolParser::get_symbol(std::string name) const {
  65     for(symbol_vector_t::const_iterator i = symbol_vector.begin(); i != symbol_vector.end(); i ++) {
  66         if((*i)->get_symbol_name() == name) return *i;
  67     }
  68     return NULL;
  69 }
  70
  71 void SymbolParser::dump_symbols() const {
  72     std::cout << "Symbol dump: \n";
  73     for(symbol_vector_t::const_iterator i = symbol_vector.begin(); i != symbol_vector.end(); i ++) {
  74         std::cout << "\tSymbol: name is \"" << (*i)->get_symbol_name() << "\", address is 0x" << std::hex << (*i)->get_address() << std::dec << std::endl;
  75     }
  76 }
  77
  78 } // namespace ELF
  79 } // namespace Monitor
  80 } // namespace Aesalon