void parse_elf (char* file_name)
{
init_elf_parser (file_name);
if (architecture == ELFCLASS32)
{
get_num_sections ();
get_section_names ();
parse_sections ();
get_entry_point ();
find_main ();
}
else
{
get_num_sections64 ();
get_section_names64 ();
parse_sections64 ();
get_entry_point64 ();
find_main64 ();
}
}
//Initialize some globals that have to deal with the ELF we're reading
//Note: this must be called whether or not you're actually using the parser
void init_elf_parser (char* file_name)
{
init_file_buf (file_name);
Elf32_Ehdr* header = (Elf32_Ehdr*)file_buf;
Elf64_Ehdr* header64 = (Elf64_Ehdr*)file_buf;
//Sanity check
header = (Elf32_Ehdr*)file_buf;
if (header->e_ident [EI_MAG0] != 0x7f || header->e_ident [EI_MAG1] != 'E' || header->e_ident [EI_MAG2] != 'L' || header->e_ident [EI_MAG3] != 'F')
{
elf_parser_cleanup ();
printf ("CRITICAL ERROR: Not an ELF file.\n");
exit (-1);
}
if (header->e_shoff > file_size)
{
elf_parser_cleanup ();
printf ("ERROR: ELF file is corrupt. Invalid section header offset. Sections have probably been stripped, please specify a starting address.\n");
exit (-1);
}
if (header->e_phoff > file_size)
{
elf_parser_cleanup ();
printf ("CRITICAL ERROR: ELF file is corrupt Invalid program header offset.\n");
exit (-1);
}
architecture = header->e_ident [EI_CLASS];
if (architecture == ELFCLASSNONE)
{
printf ("CRITICAL ERROR: Invalid architecture");
exit (-1);
}
else if (architecture == ELFCLASS32)
{
Elf32_Phdr* program_headers = (Elf32_Phdr*)(file_buf + header->e_phoff);
int i;
for (i = 0; i < header->e_phnum; i ++)
{
if (program_headers [i].p_type == PT_LOAD)
{
base_addr = program_headers [i].p_vaddr;
executable_segment_size = program_headers [i].p_filesz;
break;
}
}
if (i == header->e_phnum)
{
printf ("CRITICAL ERROR: No loadable segments\n");
exit (-1);
}
symbol_table.arch1 = NULL;
symbol_table_end.arch1 = NULL;
num_relocs = 0;
string_table = NULL;
get_dyn_syms ();
get_entry_point ();
get_text ();
}
else if (architecture == ELFCLASS64)
{
Elf64_Phdr* program_headers = (Elf64_Phdr*)(file_buf + header64->e_phoff);
int i;
for (i = 0; i < header64->e_phnum; i ++)
{
if (program_headers [i].p_type == PT_LOAD)
{
base_addr = program_headers [i].p_vaddr;
executable_segment_size = program_headers [i].p_filesz;
break;
}
}
if (i == header64->e_phnum)
{
printf ("CRITICAL ERROR: No loadable segments\n");
exit (-1);
}
symbol_table.arch2 = NULL;
symbol_table_end.arch2 = NULL;
num_relocs = 0;
string_table = NULL;
get_dyn_syms64 ();
get_entry_point64 ();
get_text64 ();
}
else
{
printf ("CRITICAL ERROR: Invalid ELF class %d", architecture);
exit (-1);
}
}
