Dobby/elf_symbol.c at master · madoci/Dobby · GitHub

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#include "elf_symbol.h"

#include "elf_io.h"


/* READ SYMBOL TABLE */

Elf32_Sym read_sym(unsigned char* line){

  Elf32_Sym sym;

  read_32bits(&(sym.st_name), line);
  line += 4;
  read_32bits(&(sym.st_value), line);
  line += 4;
  read_32bits(&(sym.st_size), line);
  line += 4;
  read_8bits(&(sym.st_info), line);
  line += 1;
  read_8bits(&(sym.st_other), line);
  line += 1;
  read_16bits(&(sym.st_shndx), line);

  return sym;
}


void read_elf_symbol_table(unsigned char* symtab, Elf32_Shdr* symbol_header, Elf32_Sym sym_table[]){
  const unsigned int num_symbols = symbol_header->sh_size / sizeof(Elf32_Sym);
  unsigned int i;
  for (i=0; i<num_symbols; i++){
    unsigned char* line = symtab + i * sizeof(Elf32_Sym); //fseek(f, symbol_header->sh_offset + i * sizeof(Elf32_Sym), SEEK_SET);
    sym_table[i] = read_sym(line);
  }
}


/* DISPLAY SYMBOL TABLE */

char * symbol_vis(unsigned char other){
  switch (ELF32_ST_VIS(other)){
    case STV_DEFAULT:
      return "DEFAULT";
    case STV_INTERNAL:
      return "INTERNAL";
    case STV_HIDDEN:
      return "HIDDEN";
    case STV_PROTECTED:
      return "PROTECTED";
    default:
      return "Error";
  }
}


char * symbol_link(unsigned char info){
  switch (ELF32_ST_BIND(info)){
    case STB_LOCAL:
      return "LOCAL";
    case STB_GLOBAL:
      return "GLOBAL";
    case STB_WEAK:
      return "WEAK";
    case STB_LOPROC:
      return "LOPROC";
    case STB_HIPROC:
      return "HIPROC";
    default:
      return "Error";
  }
}


char * symbol_type(unsigned char info){
  switch (ELF32_ST_TYPE(info)){
    case STT_NOTYPE:
      return "NOTYPE";
    case STT_OBJECT:
      return "OBJECT";
    case STT_FUNC:
      return "FUNC";
    case STT_SECTION:
      return "SECTION";
    case STT_FILE:
      return "FILE";
    case STT_LOPROC:
      return "LOPROC";
    case STT_HIPROC:
      return "HIPROC";
    default:
      return "Error";
  }
}


void display_symbol_table(Elf32_Sym sym_table[], unsigned int num_symbols, unsigned char *string_table, unsigned char *section_name){
  printf("\nLa table des symboles \"%s\" contient %d entrées \n\n", section_name, num_symbols);
  printf("%2s\t %8s\t %-1s\t %-7s\t %-6s\t %-9s\t %-3s\t %-12s\n",
         "Num:","Valeur","Tail","Type","Lien","Vis","Ndx","Nom");

  unsigned int i;
  for (i=0 ; i<num_symbols; i++){
    const unsigned char *nom = string_table + sym_table[i].st_name;
    const Elf32_Addr valeur = sym_table[i].st_value;
    const Elf32_Word size = sym_table[i].st_size;
    char * type = symbol_type(sym_table[i].st_info);
    char * lien = symbol_link(sym_table[i].st_info);
    char * vis = symbol_vis(sym_table[i].st_other);
    Elf32_Half ndx = sym_table[i].st_shndx;

    printf("%2d:\t %08x\t %-1d\t %-7s\t %-6s\t %-9s\t",
           i, valeur, size, type, lien, vis);
    switch(ndx){
      case SHN_ABS:
        printf(" ABS\t");
        break;
      case SHN_COMMON:
        printf(" COM\t");
        break;
      case SHN_UNDEF:
        printf(" UND\t");
        break;
      default:
        printf(" %-3d\t", ndx);
        break;
    }
    printf(" %-12s\n",nom);
  }
}