path: root/md/writeup/list_linux_elf_section_names.md

title: List ELF section names
keywords: elf,sections,linux

# List ELF section names
Every ELF (Executable Linux Format) file has standard structure.
There is section names that used to identify purpose of section.

Here is example how to write all names of all ELF sections.

Here is steps that we have taken:  
1. Find String Table Section  
2. Get all section names from string table section  
3. Run trough all section an get names of sections  

First of all we need get ELF header (Elf32_Ehdr) from position 0.
ELF header have offset of section headers (Elf32_Ehdr.e_shoff).

Sting table section have attributes with help us to recognize it:  
1. string table section header address in memory (Elf32_Shdr.sh_addr) is 0  
2. its type (Elf32_Shdr.sh_type) is SHT_STRTAB = 3  
3. and it is first section with such attributes  

To get trough all sections we make for cycle. We can get number
of sections from (Elf32_Ehdr.e_shnum) .
we run all trough all sections and checking for 3 string table section
rules.

```c
for ( iter_s=0; iter_s < ELFheader.e_shnum; iter_s++  )
    {
        fseek( f, ELFheader.e_shoff+(ELFheader.e_shentsize*iter_s), SEEK_SET);
        fread( &STRheader, ELFheader.e_shentsize, 1, f );
        if ((STRheader.sh_type == SHT_STRTAB) && 
            (STRheader.sh_addr == 0x00000000))
        {
            //some code
            iter_s=ELFheader.e_shnum+1; //this is to exit from for cycle
        }
    }
```

String table section has all section names as strings. Section name
is in (Elf32_Shdr.sh_name) as position number of strings first symbol.

All string table values we read inside buffer

```c
fseek( f, STRheader.sh_offset, SEEK_SET);
fread( STR_buffer, STRheader.sh_size, 1, f);
```

Now we can get section name with

```c
printf("%s\n", STR_buffer+ITERheader.sh_name);
```

This is example code to get some info from ELF file. There is allot other
info that can be gained from ELF file.



## Downloads
elf_section_list.zip - 
2KiB - http://archive.main.lv/files/writeup/list_elf_section_names/elf_section_list.zip