external/bsd/libelf/dist/elf_next.c

   1 /*      $NetBSD$        */
   2
   3 /*-
   4  * Copyright (c) 2006 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 /* __FBSDID("$FreeBSD: src/lib/libelf/elf_next.c,v 1.1.10.1.2.1 2009/10/25 01:10:29 kensmith Exp $"); */
  31
  32 #include <ar.h>
  33 #include <assert.h>
  34 #include <libelf.h>
  35
  36 #include "_libelf.h"
  37
  38 Elf_Cmd
  39 elf_next(Elf *e)
  40 {
  41         off_t next;
  42         Elf *parent;
  43
  44         if (e == NULL)
  45                 return (ELF_C_NULL);
  46
  47          if ((parent = e->e_parent) == NULL) {
  48                  LIBELF_SET_ERROR(ARGUMENT, 0);
  49                  return (ELF_C_NULL);
  50          }
  51
  52         assert (parent->e_kind == ELF_K_AR);
  53         assert (parent->e_cmd == ELF_C_READ);
  54         assert((uintptr_t) e->e_rawfile % 2 == 0);
  55         assert(e->e_rawfile > parent->e_rawfile);
  56
  57         next = e->e_rawfile - parent->e_rawfile + e->e_rawsize;
  58         next = (next + 1) & ~1; /* round up to an even boundary */
  59
  60         parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ? (off_t) 0 : next;
  61
  62         return (ELF_C_READ);
  63 }