xref: /dflybsd-src/contrib/elftoolchain/libelf/elf_next.c (revision 91deece701e3d2bfb30869db2dd6a3c0d67cfae0)
1*f8fb3368SJohn Marino /*-
2*f8fb3368SJohn Marino  * Copyright (c) 2006,2008 Joseph Koshy
3*f8fb3368SJohn Marino  * All rights reserved.
4*f8fb3368SJohn Marino  *
5*f8fb3368SJohn Marino  * Redistribution and use in source and binary forms, with or without
6*f8fb3368SJohn Marino  * modification, are permitted provided that the following conditions
7*f8fb3368SJohn Marino  * are met:
8*f8fb3368SJohn Marino  * 1. Redistributions of source code must retain the above copyright
9*f8fb3368SJohn Marino  *    notice, this list of conditions and the following disclaimer.
10*f8fb3368SJohn Marino  * 2. Redistributions in binary form must reproduce the above copyright
11*f8fb3368SJohn Marino  *    notice, this list of conditions and the following disclaimer in the
12*f8fb3368SJohn Marino  *    documentation and/or other materials provided with the distribution.
13*f8fb3368SJohn Marino  *
14*f8fb3368SJohn Marino  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*f8fb3368SJohn Marino  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*f8fb3368SJohn Marino  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*f8fb3368SJohn Marino  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*f8fb3368SJohn Marino  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*f8fb3368SJohn Marino  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*f8fb3368SJohn Marino  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*f8fb3368SJohn Marino  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*f8fb3368SJohn Marino  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*f8fb3368SJohn Marino  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*f8fb3368SJohn Marino  * SUCH DAMAGE.
25*f8fb3368SJohn Marino  */
26*f8fb3368SJohn Marino 
27*f8fb3368SJohn Marino #include <ar.h>
28*f8fb3368SJohn Marino #include <assert.h>
29*f8fb3368SJohn Marino #include <libelf.h>
30*f8fb3368SJohn Marino 
31*f8fb3368SJohn Marino #include "_libelf.h"
32*f8fb3368SJohn Marino 
33*f8fb3368SJohn Marino ELFTC_VCSID("$Id: elf_next.c 3174 2015-03-27 17:13:41Z emaste $");
34*f8fb3368SJohn Marino 
35*f8fb3368SJohn Marino Elf_Cmd
elf_next(Elf * e)36*f8fb3368SJohn Marino elf_next(Elf *e)
37*f8fb3368SJohn Marino {
38*f8fb3368SJohn Marino 	off_t next;
39*f8fb3368SJohn Marino 	Elf *parent;
40*f8fb3368SJohn Marino 
41*f8fb3368SJohn Marino 	if (e == NULL)
42*f8fb3368SJohn Marino 		return (ELF_C_NULL);
43*f8fb3368SJohn Marino 
44*f8fb3368SJohn Marino 	 if ((parent = e->e_parent) == NULL) {
45*f8fb3368SJohn Marino 		 LIBELF_SET_ERROR(ARGUMENT, 0);
46*f8fb3368SJohn Marino 		 return (ELF_C_NULL);
47*f8fb3368SJohn Marino 	 }
48*f8fb3368SJohn Marino 
49*f8fb3368SJohn Marino 	assert(parent->e_kind == ELF_K_AR);
50*f8fb3368SJohn Marino 	assert(parent->e_cmd == ELF_C_READ);
51*f8fb3368SJohn Marino 	assert(e->e_rawfile > parent->e_rawfile);
52*f8fb3368SJohn Marino 
53*f8fb3368SJohn Marino 	next = e->e_rawfile - parent->e_rawfile + (off_t) e->e_rawsize;
54*f8fb3368SJohn Marino 	next = (next + 1) & ~1;	/* round up to an even boundary */
55*f8fb3368SJohn Marino 
56*f8fb3368SJohn Marino 	/*
57*f8fb3368SJohn Marino 	 * Setup the 'e_next' field of the archive descriptor for the
58*f8fb3368SJohn Marino 	 * next call to 'elf_begin()'.
59*f8fb3368SJohn Marino 	 */
60*f8fb3368SJohn Marino 	parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ?
61*f8fb3368SJohn Marino 	    (off_t) 0 : next;
62*f8fb3368SJohn Marino 
63*f8fb3368SJohn Marino 	return (ELF_C_READ);
64*f8fb3368SJohn Marino }
65