libelf/gelf_rawchunk.c

/* Retrieve uninterpreted chunk of the file contents.
   Copyright (C) 2002 Red Hat, Inc.
   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, version 2.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <libelf.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>

#include "libelfP.h"


char *
gelf_rawchunk (elf, offset, size)
     Elf *elf;
     GElf_Off offset;
     GElf_Word size;
{
  if (elf == NULL)
    {
      /* No valid descriptor.  */
      __libelf_seterrno (ELF_E_INVALID_HANDLE);
      return NULL;
    }

  if (offset >= elf->maximum_size
      || offset + size >= elf->maximum_size
      || offset + size < offset)
    {
      /* Invalid request.  */
      __libelf_seterrno (ELF_E_INVALID_OP);
      return NULL;
    }

  /* If the file is mmap'ed return an appropriate pointer.  */
  if (elf->map_address != NULL)
    return (char *) elf->map_address + elf->start_offset + offset;

  /* We allocate the memory and read the data from the file.  */
  char *result = (char *) malloc (size);
  if (result == NULL)
    __libelf_seterrno (ELF_E_NOMEM);
  else
    /* Read the file content.  */
    if ((size_t) pread (elf->fildes, result, size, elf->start_offset + offset)
	!= size)
      {
	/* Something went wrong.  */
	__libelf_seterrno (ELF_E_READ_ERROR);
	free (result);
      }

  return result;
}