external/bsd/elftoolchain/dist/libelf/elf_rand.c

   1 /*      $NetBSD: elf_rand.c,v 1.2 2014/03/09 16:58:04 christos Exp $    */
   2
   3 /*-
   4  * Copyright (c) 2006,2008 Joseph Koshy
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30
  31 #include <ar.h>
  32 #include <libelf.h>
  33
  34 #include "_libelf.h"
  35
  36 __RCSID("$NetBSD: elf_rand.c,v 1.2 2014/03/09 16:58:04 christos Exp $");
  37 ELFTC_VCSID("Id: elf_rand.c 2225 2011-11-26 18:55:54Z jkoshy ");
  38
  39 off_t
  40 elf_rand(Elf *ar, off_t offset)
  41 {
  42         struct ar_hdr *arh;
  43
  44         if (ar == NULL || ar->e_kind != ELF_K_AR ||
  45             (offset & 1) || offset < SARMAG ||
  46             offset + sizeof(struct ar_hdr) >= ar->e_rawsize) {
  47                 LIBELF_SET_ERROR(ARGUMENT, 0);
  48                 return 0;
  49         }
  50
  51         arh = (struct ar_hdr *) (ar->e_rawfile + offset);
  52
  53         /* a too simple sanity check */
  54         if (arh->ar_fmag[0] != '`' || arh->ar_fmag[1] != '\n') {
  55                 LIBELF_SET_ERROR(ARCHIVE, 0);
  56                 return 0;
  57         }
  58
  59         ar->e_u.e_ar.e_next = offset;
  60
  61         return (offset);
  62 }