xref: /freebsd/contrib/elftoolchain/libelf/elf_next.c (revision 2de3b87a120614a3b053be7dd845b72f1e9ce804)
1*2de3b87aSKai Wang /*-
2*2de3b87aSKai Wang  * Copyright (c) 2006,2008 Joseph Koshy
3*2de3b87aSKai Wang  * All rights reserved.
4*2de3b87aSKai Wang  *
5*2de3b87aSKai Wang  * Redistribution and use in source and binary forms, with or without
6*2de3b87aSKai Wang  * modification, are permitted provided that the following conditions
7*2de3b87aSKai Wang  * are met:
8*2de3b87aSKai Wang  * 1. Redistributions of source code must retain the above copyright
9*2de3b87aSKai Wang  *    notice, this list of conditions and the following disclaimer.
10*2de3b87aSKai Wang  * 2. Redistributions in binary form must reproduce the above copyright
11*2de3b87aSKai Wang  *    notice, this list of conditions and the following disclaimer in the
12*2de3b87aSKai Wang  *    documentation and/or other materials provided with the distribution.
13*2de3b87aSKai Wang  *
14*2de3b87aSKai Wang  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*2de3b87aSKai Wang  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*2de3b87aSKai Wang  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*2de3b87aSKai Wang  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*2de3b87aSKai Wang  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*2de3b87aSKai Wang  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*2de3b87aSKai Wang  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*2de3b87aSKai Wang  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*2de3b87aSKai Wang  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*2de3b87aSKai Wang  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*2de3b87aSKai Wang  * SUCH DAMAGE.
25*2de3b87aSKai Wang  */
26*2de3b87aSKai Wang 
27*2de3b87aSKai Wang #include <sys/cdefs.h>
28*2de3b87aSKai Wang 
29*2de3b87aSKai Wang #include <ar.h>
30*2de3b87aSKai Wang #include <assert.h>
31*2de3b87aSKai Wang #include <libelf.h>
32*2de3b87aSKai Wang 
33*2de3b87aSKai Wang #include "_libelf.h"
34*2de3b87aSKai Wang 
35*2de3b87aSKai Wang ELFTC_VCSID("$Id: elf_next.c 2225 2011-11-26 18:55:54Z jkoshy $");
36*2de3b87aSKai Wang 
37*2de3b87aSKai Wang Elf_Cmd
38*2de3b87aSKai Wang elf_next(Elf *e)
39*2de3b87aSKai Wang {
40*2de3b87aSKai Wang 	off_t next;
41*2de3b87aSKai Wang 	Elf *parent;
42*2de3b87aSKai Wang 
43*2de3b87aSKai Wang 	if (e == NULL)
44*2de3b87aSKai Wang 		return (ELF_C_NULL);
45*2de3b87aSKai Wang 
46*2de3b87aSKai Wang 	 if ((parent = e->e_parent) == NULL) {
47*2de3b87aSKai Wang 		 LIBELF_SET_ERROR(ARGUMENT, 0);
48*2de3b87aSKai Wang 		 return (ELF_C_NULL);
49*2de3b87aSKai Wang 	 }
50*2de3b87aSKai Wang 
51*2de3b87aSKai Wang 	assert (parent->e_kind == ELF_K_AR);
52*2de3b87aSKai Wang 	assert (parent->e_cmd == ELF_C_READ);
53*2de3b87aSKai Wang 	assert(e->e_rawfile > parent->e_rawfile);
54*2de3b87aSKai Wang 
55*2de3b87aSKai Wang 	next = e->e_rawfile - parent->e_rawfile + e->e_rawsize;
56*2de3b87aSKai Wang 	next = (next + 1) & ~1;	/* round up to an even boundary */
57*2de3b87aSKai Wang 
58*2de3b87aSKai Wang 	parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ?
59*2de3b87aSKai Wang 	    (off_t) 0 : next;
60*2de3b87aSKai Wang 
61*2de3b87aSKai Wang 	return (ELF_C_READ);
62*2de3b87aSKai Wang }
63