1/*-
2 * Copyright (c) 2006 Joseph Koshy
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <ar.h>
31#include <assert.h>
32#include <libelf.h>
33
34#include "_libelf.h"
35
36Elf_Cmd
37elf_next(Elf *e)
38{
39	off_t next;
40	Elf *parent;
41
42	if (e == NULL)
43		return (ELF_C_NULL);
44
45	 if ((parent = e->e_parent) == NULL) {
46		 LIBELF_SET_ERROR(ARGUMENT, 0);
47		 return (ELF_C_NULL);
48	 }
49
50	assert (parent->e_kind == ELF_K_AR);
51	assert (parent->e_cmd == ELF_C_READ);
52	assert((uintptr_t) e->e_rawfile % 2 == 0);
53	assert(e->e_rawfile > parent->e_rawfile);
54
55	next = e->e_rawfile - parent->e_rawfile + e->e_rawsize;
56	next = (next + 1) & ~1;	/* round up to an even boundary */
57
58	parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ? (off_t) 0 : next;
59
60	return (ELF_C_READ);
61}
62