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/*-
* Copyright (c) 2006,2008 Joseph Koshy
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <ar.h>
#include <assert.h>
#include <libelf.h>
#include "_libelf.h"
ELFTC_VCSID("$Id: elf_next.c,v 1.2 2019/03/19 02:31:35 jsg Exp $");
Elf_Cmd
elf_next(Elf *e)
{
off_t next;
Elf *parent;
if (e == NULL)
return (ELF_C_NULL);
if ((parent = e->e_parent) == NULL) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (ELF_C_NULL);
}
assert(parent->e_kind == ELF_K_AR);
assert(parent->e_cmd == ELF_C_READ);
assert(e->e_rawfile > parent->e_rawfile);
next = e->e_rawfile - parent->e_rawfile + (off_t) e->e_rawsize;
next = (next + 1) & ~1; /* round up to an even boundary */
/*
* Setup the 'e_next' field of the archive descriptor for the
* next call to 'elf_begin()'.
*/
parent->e_u.e_ar.e_next = (next >= (off_t) parent->e_rawsize) ?
(off_t) 0 : next;
/*
* Return an error if the 'e_next' field falls outside the current
* file.
*
* This check is performed after updating the parent descriptor's
* 'e_next' field so that the next call to elf_begin(3) will terminate
* traversal of a too-small archive even if client code forgets to
* check the return value from elf_next(3).
*/
if (next > (off_t) parent->e_rawsize) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (ELF_C_NULL);
}
return (ELF_C_READ);
}
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