Line data    Source code

       1             : /* Return section compression header.
       2             :    Copyright (C) 2015 Red Hat, Inc.
       3             :    This file is part of elfutils.
       4             : 
       5             :    This file is free software; you can redistribute it and/or modify
       6             :    it under the terms of either
       7             : 
       8             :      * the GNU Lesser General Public License as published by the Free
       9             :        Software Foundation; either version 3 of the License, or (at
      10             :        your option) any later version
      11             : 
      12             :    or
      13             : 
      14             :      * the GNU General Public License as published by the Free
      15             :        Software Foundation; either version 2 of the License, or (at
      16             :        your option) any later version
      17             : 
      18             :    or both in parallel, as here.
      19             : 
      20             :    elfutils is distributed in the hope that it will be useful, but
      21             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23             :    General Public License for more details.
      24             : 
      25             :    You should have received copies of the GNU General Public License and
      26             :    the GNU Lesser General Public License along with this program.  If
      27             :    not, see <http://www.gnu.org/licenses/>.  */
      28             : 
      29             : #ifdef HAVE_CONFIG_H
      30             : # include <config.h>
      31             : #endif
      32             : 
      33             : #include <libelf.h>
      34             : #include "libelfP.h"
      35             : #include "common.h"
      36             : 
      37             : #ifndef LIBELFBITS
      38             : # define LIBELFBITS 32
      39             : #endif
      40             : 
      41             : 
      42             : ElfW2(LIBELFBITS,Chdr) *
      43         529 : elfw2(LIBELFBITS,getchdr) (Elf_Scn *scn)
      44             : {
      45         529 :   ElfW2(LIBELFBITS,Shdr) *shdr = elfw2(LIBELFBITS,getshdr) (scn);
      46         529 :   if (shdr == NULL)
      47             :     return NULL;
      48             : 
      49             :   /* Must have SHF_COMPRESSED flag set.  Allocated or no bits sections
      50             :      can never be compressed.  */
      51         528 :   if ((shdr->sh_flags & SHF_ALLOC) != 0)
      52             :     {
      53           0 :       __libelf_seterrno (ELF_E_INVALID_SECTION_FLAGS);
      54           0 :       return NULL;
      55             :     }
      56             : 
      57        1056 :   if (shdr->sh_type == SHT_NULL
      58         528 :       || shdr->sh_type == SHT_NOBITS)
      59             :     {
      60           0 :       __libelf_seterrno (ELF_E_INVALID_SECTION_TYPE);
      61           0 :       return NULL;
      62             :     }
      63             : 
      64         528 :   if ((shdr->sh_flags & SHF_COMPRESSED) == 0)
      65             :     {
      66          39 :       __libelf_seterrno (ELF_E_NOT_COMPRESSED);
      67          39 :       return NULL;
      68             :     }
      69             : 
      70             :   /* This makes sure the data is in the correct format, so we don't
      71             :      need to swap fields. */
      72         489 :   Elf_Data *d  = elf_getdata (scn, NULL);
      73         489 :   if (d == NULL)
      74             :     return NULL;
      75             : 
      76         489 :   if (d->d_size < sizeof (ElfW2(LIBELFBITS,Chdr)) || d->d_buf == NULL)
      77             :     {
      78           0 :       __libelf_seterrno (ELF_E_INVALID_DATA);
      79           0 :       return NULL;
      80             :     }
      81             : 
      82             :   return (ElfW2(LIBELFBITS,Chdr) *) d->d_buf;
      83             : }