path: root/net/batman-adv/bat_iv_ogm.c

/*
 * Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
 *
 * Marek Lindner, Simon Wunderlich
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 *
 */

#include "main.h"
#include "translation-table.h"
#include "ring_buffer.h"
#include "originator.h"
#include "routing.h"
#include "gateway_common.h"
#include "gateway_client.h"
#include "hard-interface.h"
#include "send.h"
#include "bat_algo.h"

static int bat_iv_ogm_iface_enable(struct hard_iface *hard_iface)
{
	struct batman_ogm_packet *batman_ogm_packet;
	uint32_t random_seqno;
	int res = -1;

	/* randomize initial seqno to avoid collision */
	get_random_bytes(&random_seqno, sizeof(random_seqno));
	atomic_set(&hard_iface->seqno, random_seqno);

	hard_iface->packet_len = BATMAN_OGM_HLEN;
	hard_iface->packet_buff = kmalloc(hard_iface->packet_len, GFP_ATOMIC);

	if (!hard_iface->packet_buff)
		goto out;

	batman_ogm_packet = (struct batman_ogm_packet *)hard_iface->packet_buff;
	batman_ogm_packet->header.packet_type = BAT_IV_OGM;
	batman_ogm_packet->header.version = COMPAT_VERSION;
	batman_ogm_packet->header.ttl = 2;
	batman_ogm_packet->flags = NO_FLAGS;
	batman_ogm_packet->tq = TQ_MAX_VALUE;
	batman_ogm_packet->tt_num_changes = 0;
	batman_ogm_packet->ttvn = 0;

	res = 0;

out:
	return res;
}

static void bat_iv_ogm_iface_disable(struct hard_iface *hard_iface)
{
	kfree(hard_iface->packet_buff);
	hard_iface->packet_buff = NULL;
}

static void bat_iv_ogm_primary_iface_set(struct hard_iface *hard_iface)
{
	struct batman_ogm_packet *batman_ogm_packet;

	batman_ogm_packet = (struct batman_ogm_packet *)hard_iface->packet_buff;
	batman_ogm_packet->flags = PRIMARIES_FIRST_HOP;
	batman_ogm_packet->header.ttl = TTL;
}

static void bat_iv_ogm_update_mac(struct hard_iface *hard_iface)
{
	struct batman_ogm_packet *batman_ogm_packet;

	batman_ogm_packet = (struct batman_ogm_packet *)hard_iface->packet_buff;
	memcpy(batman_ogm_packet->orig,
	       hard_iface->net_dev->dev_addr, ETH_ALEN);
	memcpy(batman_ogm_packet->prev_sender,
	       hard_iface->net_dev->dev_addr, ETH_ALEN);
}

/* when do we schedule our own ogm to be sent */
static unsigned long bat_iv_ogm_emit_send_time(const struct bat_priv *bat_priv)
{
	return jiffies + msecs_to_jiffies(
		   atomic_read(&bat_priv->orig_interval) -
		   JITTER + (random32() % 2*JITTER));
}

/* when do we schedule a ogm packet to be sent */
static unsigned long bat_iv_ogm_fwd_send_time(void)
{
	return jiffies + msecs_to_jiffies(random32() % (JITTER/2));
}

/* apply hop penalty for a normal link */
static uint8_t hop_penalty(uint8_t tq, const struct bat_priv *bat_priv)
{
	int hop_penalty = atomic_read