iwd/src/ie.c

/*
 *
 *  Wireless daemon for Linux
 *
 *  Copyright (C) 2014  Intel Corporation. All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#include <ell/ell.h>

#include "ie.h"

void ie_tlv_iter_init(struct ie_tlv_iter *iter, const unsigned char *tlv,
			unsigned int len)
{
	iter->tlv = tlv;
	iter->max = len;
	iter->pos = 0;
}

void ie_tlv_iter_recurse(struct ie_tlv_iter *iter,
				struct ie_tlv_iter *recurse)
{
	recurse->tlv = iter->data;
	recurse->max = iter->len;
	recurse->pos = 0;
}

unsigned int ie_tlv_iter_get_tag(struct ie_tlv_iter *iter)
{
	return iter->tag;
}

bool ie_tlv_iter_next(struct ie_tlv_iter *iter)
{
	const unsigned char *tlv = iter->tlv + iter->pos;
	const unsigned char *end = iter->tlv + iter->max;
	unsigned int tag;
	unsigned int len;

	if (iter->pos >= iter->max)
		return false;

	tag = *tlv++;
	len = *tlv++;

	if (tlv + len > end)
		return false;

	iter->tag = tag;
	iter->len = len;
	iter->data = tlv;

	iter->pos = tlv + len - iter->tlv;

	return true;
}