elftools/elf/notes.py

   1 #-------------------------------------------------------------------------------
   2 # elftools: elf/notes.py
   3 #
   4 # ELF notes
   5 #
   6 # Eli Bendersky (eliben@gmail.com)
   7 # This code is in the public domain
   8 #-------------------------------------------------------------------------------
   9 from ..common.py3compat import bytes2str
  10 from ..common.utils import struct_parse, roundup
  11 from ..construct import CString
  12
  13
  14 def iter_notes(elffile, offset, size):
  15     """ Yield all the notes in a section or segment.
  16     """
  17     end = offset + size
  18     while offset < end:
  19         note = struct_parse(
  20             elffile.structs.Elf_Nhdr,
  21             elffile.stream,
  22             stream_pos=offset)
  23         note['n_offset'] = offset
  24         offset += elffile.structs.Elf_Nhdr.sizeof()
  25         elffile.stream.seek(offset)
  26         # n_namesz is 4-byte aligned.
  27         disk_namesz = roundup(note['n_namesz'], 2)
  28         note['n_name'] = bytes2str(
  29             CString('').parse(elffile.stream.read(disk_namesz)))
  30         offset += disk_namesz
  31
  32         desc_data = bytes2str(elffile.stream.read(note['n_descsz']))
  33         note['n_descdata'] = desc_data
  34         if note['n_type'] == 'NT_GNU_ABI_TAG':
  35             note['n_desc'] = struct_parse(elffile.structs.Elf_abi,
  36                                           elffile.stream,
  37                                           offset)
  38         elif note['n_type'] == 'NT_GNU_BUILD_ID':
  39             note['n_desc'] = ''.join('%.2x' % ord(b) for b in desc_data)
  40         elif note['n_type'] == 'NT_PRPSINFO':
  41             note['n_desc'] = struct_parse(elffile.structs.Elf_Prpsinfo,
  42                                           elffile.stream,
  43                                           offset)
  44         elif note['n_type'] == 'NT_FILE':
  45             note['n_desc'] = struct_parse(elffile.structs.Elf_Nt_File,
  46                                           elffile.stream,
  47                                           offset)
  48         else:
  49             note['n_desc'] = desc_data
  50         offset += roundup(note['n_descsz'], 2)
  51         note['n_size'] = offset - note['n_offset']
  52         yield note