1  /*-
 2   * Copyright (c) 2006,2008 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  
29  #include <ar.h>
30  #include <assert.h>
31  #include <libelf.h>
32  
33  #include "_libelf.h"
34  
35  ELFTC_VCSID("$Id$");
36  
37  Elf_Cmd
38  elf_next(Elf *e)
39  {
40  	off_t next;
41  	Elf *parent;
42  
43  	if (e == NULL)
44  		return (ELF_C_NULL);
45  
46  	 if ((parent = e->e_parent) == NULL) {
47  		 LIBELF_SET_ERROR(ARGUMENT, 0);
48  		 return (ELF_C_NULL);
49  	 }
50  
51  	assert(parent->e_kind == ELF_K_AR);
52  	assert(parent->e_cmd == ELF_C_READ);
53  	assert(e->e_rawfile > parent->e_rawfile);
54  
55  	next = e->e_rawfile - parent->e_rawfile + (off_t) e->e_rawsize;
56  	next = (next + 1) & ~1;	/* round up to an even boundary */
57  
58  	/*
59  	 * Setup the 'e_next' field of the archive descriptor for the
60  	 * next call to 'elf_begin()'.
61  	 */
62  	parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ?
63  	    (off_t) 0 : next;
64  
65  	return (ELF_C_READ);
66  }