xref: /freebsd/contrib/elftoolchain/libelf/elf_next.c (revision cf781b2e16c26535788abe648f5917f4db09c123)
12de3b87aSKai Wang /*-
22de3b87aSKai Wang  * Copyright (c) 2006,2008 Joseph Koshy
32de3b87aSKai Wang  * All rights reserved.
42de3b87aSKai Wang  *
52de3b87aSKai Wang  * Redistribution and use in source and binary forms, with or without
62de3b87aSKai Wang  * modification, are permitted provided that the following conditions
72de3b87aSKai Wang  * are met:
82de3b87aSKai Wang  * 1. Redistributions of source code must retain the above copyright
92de3b87aSKai Wang  *    notice, this list of conditions and the following disclaimer.
102de3b87aSKai Wang  * 2. Redistributions in binary form must reproduce the above copyright
112de3b87aSKai Wang  *    notice, this list of conditions and the following disclaimer in the
122de3b87aSKai Wang  *    documentation and/or other materials provided with the distribution.
132de3b87aSKai Wang  *
142de3b87aSKai Wang  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
152de3b87aSKai Wang  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
162de3b87aSKai Wang  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
172de3b87aSKai Wang  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
182de3b87aSKai Wang  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
192de3b87aSKai Wang  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
202de3b87aSKai Wang  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
212de3b87aSKai Wang  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
222de3b87aSKai Wang  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
232de3b87aSKai Wang  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
242de3b87aSKai Wang  * SUCH DAMAGE.
252de3b87aSKai Wang  */
262de3b87aSKai Wang 
272de3b87aSKai Wang #include <sys/cdefs.h>
282de3b87aSKai Wang 
292de3b87aSKai Wang #include <ar.h>
302de3b87aSKai Wang #include <assert.h>
312de3b87aSKai Wang #include <libelf.h>
322de3b87aSKai Wang 
332de3b87aSKai Wang #include "_libelf.h"
342de3b87aSKai Wang 
35*cf781b2eSEd Maste ELFTC_VCSID("$Id: elf_next.c 2989 2014-03-17 09:56:46Z jkoshy $");
362de3b87aSKai Wang 
372de3b87aSKai Wang Elf_Cmd
382de3b87aSKai Wang elf_next(Elf *e)
392de3b87aSKai Wang {
402de3b87aSKai Wang 	off_t next;
412de3b87aSKai Wang 	Elf *parent;
422de3b87aSKai Wang 
432de3b87aSKai Wang 	if (e == NULL)
442de3b87aSKai Wang 		return (ELF_C_NULL);
452de3b87aSKai Wang 
462de3b87aSKai Wang 	 if ((parent = e->e_parent) == NULL) {
472de3b87aSKai Wang 		 LIBELF_SET_ERROR(ARGUMENT, 0);
482de3b87aSKai Wang 		 return (ELF_C_NULL);
492de3b87aSKai Wang 	 }
502de3b87aSKai Wang 
512de3b87aSKai Wang 	assert(parent->e_kind == ELF_K_AR);
522de3b87aSKai Wang 	assert(parent->e_cmd == ELF_C_READ);
532de3b87aSKai Wang 	assert(e->e_rawfile > parent->e_rawfile);
542de3b87aSKai Wang 
55*cf781b2eSEd Maste 	next = e->e_rawfile - parent->e_rawfile + (off_t) e->e_rawsize;
562de3b87aSKai Wang 	next = (next + 1) & ~1;	/* round up to an even boundary */
572de3b87aSKai Wang 
58*cf781b2eSEd Maste 	/*
59*cf781b2eSEd Maste 	 * Setup the 'e_next' field of the archive descriptor for the
60*cf781b2eSEd Maste 	 * next call to 'elf_begin()'.
61*cf781b2eSEd Maste 	 */
622de3b87aSKai Wang 	parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ?
632de3b87aSKai Wang 	    (off_t) 0 : next;
642de3b87aSKai Wang 
652de3b87aSKai Wang 	return (ELF_C_READ);
662de3b87aSKai Wang }
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