[deliverable/linux.git] / net / batman-adv / gateway_client.c

/*
 * Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
 *
 * Marek Lindner
 *
 * 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 "bat_sysfs.h"
#include "gateway_client.h"
#include "gateway_common.h"
#include "hard-interface.h"
#include "originator.h"
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
#include <linux/if_vlan.h>

static void gw_node_free_ref(struct gw_node *gw_node)
{
	if (atomic_dec_and_test(&gw_node->refcount))
		kfree_rcu(gw_node, rcu);
}

static struct gw_node *gw_get_selected_gw_node(struct bat_priv *bat_priv)
{
	struct gw_node *gw_node;

	rcu_read_lock();
	gw_node = rcu_dereference(bat_priv->curr_gw);
	if (!gw_node)
		goto out;

	if (!atomic_inc_not_zero(&gw_node->refcount))
		gw_node = NULL;

out:
	rcu_read_unlock();
	return gw_node;
}

struct orig_node *gw_get_selected_orig(struct bat_priv *bat_priv)
{
	struct gw_node *gw_node;
	struct orig_node *orig_node = NULL;

	gw_node = gw_get_selected_gw_node(bat_priv);
	if (!gw_node)
		goto out;

	rcu_read_lock();
	orig_node = gw_node->orig_node;
	if (!orig_node)
		goto unlock;

	if (!atomic_inc_not_zero(&orig_node->refcount))
		orig_node = NULL;

unlock:
	rcu_read_unlock();
out:
	if (gw_node)
		gw_node_free_ref(gw_node);
	return orig_node;
}

static void gw_select(struct bat_priv *bat_priv, struct gw_node *new_gw_node)
{
	struct gw_node *curr_gw_node;

	spin_lock_bh(&bat_priv->gw_list_lock);

	if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
		new_gw_node = NULL;

	curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1);
	rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);

	if (curr_gw_node)
		gw_node_free_ref(curr_gw_node);

	spin_unlock_bh(&bat_priv->gw_list_lock);
}

void gw_deselect(struct bat_priv *bat_priv)
{
	atomic_set(&bat_priv->gw_reselect, 1);
}

static struct gw_node *gw_get_best_gw_node(struct bat_priv *bat_priv)
{
	struct neigh_node *router;
	struct hlist_node *node;
	struct gw_node *gw_node, *curr_gw = NULL;
	uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
	uint8_t max_tq = 0;
	int down, up;

	rcu_read_lock();
	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
		if (gw_node->deleted)
			continue;

		router = orig_node_get_router(gw_node->orig_node);
		if (!router)
			continue;

		if (!atomic_inc_not_zero(&gw_node->refcount))
			goto next;

		switch (atomic_read(&bat_priv->gw_sel_class)) {
		case 1: /* fast connection */
			gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
					     &down, &up);

			tmp_gw_factor = (router->tq_avg * router->tq_avg *
					 down * 100 * 100) /
					 (TQ_LOCAL_WINDOW_SIZE *
					 TQ_LOCAL_WINDOW_SIZE * 64);

			if ((tmp_gw_factor > max_gw_factor) ||
			    ((tmp_gw_factor == max_gw_factor) &&
			     (router->tq_avg > max_tq))) {
				if (curr_gw)
					gw_node_free_ref(curr_gw);
				curr_gw = gw_node;
				atomic_inc(&curr_gw->refcount);
			}
			break;

		default: /**
			  * 2:  stable connection (use best statistic)
			  * 3:  fast-switch (use best statistic but change as
			  *     soon as a better gateway appears)
			  * XX: late-switch (use best statistic but change as
			  *     soon as a better gateway appears which has
			  *     $routing_class more tq points)
			  **/
			if (router->tq_avg > max_tq) {
				if (curr_gw)
					gw_node_free_ref(curr_gw);
				curr_gw = gw_node;
				atomic_inc(&curr_gw->refcount);
			}
			break;
		}

		if (router->tq_avg > max_tq)
			max_tq = router->tq_avg;

		if (tmp_gw_factor > max_gw_factor)
			max_gw_factor = tmp_gw_factor;

		gw_node_free_ref(gw_node);

next:
		neigh_node_free_ref(router);
	}
	rcu_read_unlock();

	return curr_gw;
}

void gw_election(struct bat_priv *bat_priv)
{
	struct gw_node *curr_gw = NULL, *next_gw = NULL;
	struct neigh_node *router = NULL;
	char gw_addr[18] = { '\0' };

	/**
	 * The batman daemon checks here if we already passed a full originator
	 * cycle in order to make sure we don't choose the first gateway we
	 * hear about. This check is based on the daemon's uptime which we
	 * don't have.
	 **/
	if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
		goto out;

	if (!atomic_dec_not_zero(&bat_priv->gw_reselect))
		goto out;

	curr_gw = gw_get_selected_gw_node(bat_priv);

	next_gw = gw_get_best_gw_node(bat_priv);

	if (curr_gw == next_gw)
		goto out;

	if (next_gw) {
		sprintf(gw_addr, "%pM", next_gw->orig_node->orig);

		router = orig_node_get_router(next_gw->orig_node);
		if (!router) {
			gw_deselect(bat_priv);
			goto out;
		}
	}

	if ((curr_gw) && (!next_gw)) {
		bat_dbg(DBG_BATMAN, bat_priv,
			"Removing selected gateway - no gateway in range\n");
		throw_uevent(bat_priv, UEV_GW, UEV_DEL, NULL);
	} else if ((!curr_gw) && (next_gw)) {
		bat_dbg(DBG_BATMAN, bat_priv,
			"Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
			next_gw->orig_node->orig,
			next_gw->orig_node->gw_flags,
			router->tq_avg);
		throw_uevent(bat_priv, UEV_GW, UEV_ADD, gw_addr);
	} else {
		bat_dbg(DBG_BATMAN, bat_priv,
			"Changing route to gateway %pM "
			"(gw_flags: %i, tq: %i)\n",
			next_gw->orig_node->orig,
			next_gw->orig_node->gw_flags,
			router->tq_avg);
		throw_uevent(bat_priv, UEV_GW, UEV_CHANGE, gw_addr);
	}

	gw_select(bat_priv, next_gw);

out:
	if (curr_gw)
		gw_node_free_ref(curr_gw);
	if (next_gw)
		gw_node_free_ref(next_gw);
	if (router)
		neigh_node_free_ref(router);
}

void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
{
	struct orig_node *curr_gw_orig;
	struct neigh_node *router_gw = NULL, *router_orig = NULL;
	uint8_t gw_tq_avg, orig_tq_avg;

	curr_gw_orig = gw_get_selected_orig(bat_priv);
	if (!curr_gw_orig)
		goto deselect;

	router_gw = orig_node_get_router(curr_gw_orig);
	if (!router_gw)
		goto deselect;

	/* this node already is the gateway */
	if (curr_gw_orig == orig_node)
		goto out;

	router_orig = orig_node_get_router(orig_node);
	if (!router_orig)
		goto out;

	gw_tq_avg = router_gw->tq_avg;
	orig_tq_avg = router_orig->tq_avg;

	/* the TQ value has to be better */
	if (orig_tq_avg < gw_tq_avg)
		goto out;

	/**
	 * if the routing class is greater than 3 the value tells us how much
	 * greater the TQ value of the new gateway must be
	 **/
	if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
	    (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
		goto out;

	bat_dbg(DBG_BATMAN, bat_priv,
		"Restarting gateway selection: better gateway found (tq curr: "
		"%i, tq new: %i)\n",
		gw_tq_avg, orig_tq_avg);

deselect:
	gw_deselect(bat_priv);
out:
	if (curr_gw_orig)
		orig_node_free_ref(curr_gw_orig);
	if (router_gw)
		neigh_node_free_ref(router_gw);
	if (router_orig)
		neigh_node_free_ref(router_orig);

	return;
}

static void gw_node_add(struct bat_priv *bat_priv,
			struct orig_node *orig_node, uint8_t new_gwflags)
{
	struct gw_node *gw_node;
	int down, up;

	gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
	if (!gw_node)
		return;

	INIT_HLIST_NODE(&gw_node->list);
	gw_node->orig_node = orig_node;
	atomic_set(&gw_node->refcount, 1);

	spin_lock_bh(&bat_priv->gw_list_lock);
	hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
	spin_unlock_bh(&bat_priv->gw_list_lock);

	gw_bandwidth_to_kbit(new_gwflags, &down, &up);
	bat_dbg(DBG_BATMAN, bat_priv,
		"Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
		orig_node->orig, new_gwflags,
		(down > 2048 ? down / 1024 : down),
		(down > 2048 ? "MBit" : "KBit"),
		(up > 2048 ? up / 1024 : up),
		(up > 2048 ? "MBit" : "KBit"));
}

void gw_node_update(struct bat_priv *bat_priv,
		    struct orig_node *orig_node, uint8_t new_gwflags)
{
	struct hlist_node *node;
	struct gw_node *gw_node, *curr_gw;

	/**
	 * Note: We don't need a NULL check here, since curr_gw never gets
	 * dereferenced. If curr_gw is NULL we also should not exit as we may
	 * have this gateway in our list (duplication check!) even though we
	 * have no currently selected gateway.
	 */
	curr_gw = gw_get_selected_gw_node(bat_priv);

	rcu_read_lock();
	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
		if (gw_node->orig_node != orig_node)
			continue;

		bat_dbg(DBG_BATMAN, bat_priv,
			"Gateway class of originator %pM changed from "
			"%i to %i\n",
			orig_node->orig, gw_node->orig_node->gw_flags,
			new_gwflags);

		gw_node->deleted = 0;

		if (new_gwflags == NO_FLAGS) {
			gw_node->deleted = jiffies;
			bat_dbg(DBG_BATMAN, bat_priv,
				"Gateway %pM removed from gateway list\n",
				orig_node->orig);

			if (gw_node == curr_gw)
				goto deselect;
		}

		goto unlock;
	}

	if (new_gwflags == NO_FLAGS)
		goto unlock;

	gw_node_add(bat_priv, orig_node, new_gwflags);
	goto unlock;

deselect:
	gw_deselect(bat_priv);
unlock:
	rcu_read_unlock();

	if (curr_gw)
		gw_node_free_ref(curr_gw);
}

void gw_node_delete(struct bat_priv *bat_priv, struct orig_node *orig_node)
{
	gw_node_update(bat_priv, orig_node, 0);
}

void gw_node_purge(struct bat_priv *bat_priv)
{
	struct gw_node *gw_node, *curr_gw;
	struct hlist_node *node, *node_tmp;
	unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
	int do_deselect = 0;

	curr_gw = gw_get_selected_gw_node(bat_priv);

	spin_lock_bh(&bat_priv->gw_list_lock);

	hlist_for_each_entry_safe(gw_node, node, node_tmp,
				  &bat_priv->gw_list, list) {
		if (((!gw_node->deleted) ||
		     (time_before(jiffies, gw_node->deleted + timeout))) &&
		    atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
			continue;

		if (curr_gw == gw_node)
			do_deselect = 1;

		hlist_del_rcu(&gw_node->list);
		gw_node_free_ref(gw_node);
	}

	spin_unlock_bh(&bat_priv->gw_list_lock);

	/* gw_deselect() needs to acquire the gw_list_lock */
	if (do_deselect)
		gw_deselect(bat_priv);

	if (curr_gw)
		gw_node_free_ref(curr_gw);
}

/**
 * fails if orig_node has no router
 */
static int _write_buffer_text(struct bat_priv *bat_priv, struct seq_file *seq,
			      const struct gw_node *gw_node)
{
	struct gw_node *curr_gw;
	struct neigh_node *router;
	int down, up, ret = -1;

	gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);

	router = orig_node_get_router(gw_node->orig_node);
	if (!router)
		goto out;

	curr_gw = gw_get_selected_gw_node(bat_priv);

	ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
			 (curr_gw == gw_node ? "=>" : "  "),
			 gw_node->orig_node->orig,
			 router->tq_avg, router->addr,
			 router->if_incoming->net_dev->name,
			 gw_node->orig_node->gw_flags,
			 (down > 2048 ? down / 1024 : down),
			 (down > 2048 ? "MBit" : "KBit"),
			 (up > 2048 ? up / 1024 : up),
			 (up > 2048 ? "MBit" : "KBit"));

	neigh_node_free_ref(router);
	if (curr_gw)
		gw_node_free_ref(curr_gw);
out:
	return ret;
}

int gw_client_seq_print_text(struct seq_file *seq, void *offset)
{
	struct net_device *net_dev = (struct net_device *)seq->private;
	struct bat_priv *bat_priv = netdev_priv(net_dev);
	struct hard_iface *primary_if;
	struct gw_node *gw_node;
	struct hlist_node *node;
	int gw_count = 0, ret = 0;

	primary_if = primary_if_get_selected(bat_priv);
	if (!primary_if) {
		ret = seq_printf(seq, "BATMAN mesh %s disabled - please "
				 "specify interfaces to enable it\n",
				 net_dev->name);
		goto out;
	}

	if (primary_if->if_status != IF_ACTIVE) {
		ret = seq_printf(seq, "BATMAN mesh %s disabled - "
				 "primary interface not active\n",
				 net_dev->name);
		goto out;
	}

	seq_printf(seq, "      %-12s (%s/%i) %17s [%10s]: gw_class ... "
		   "[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
		   "Gateway", "#", TQ_MAX_VALUE, "Nexthop",
		   "outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR,
		   primary_if->net_dev->name,
		   primary_if->net_dev->dev_addr, net_dev->name);

	rcu_read_lock();
	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
		if (gw_node->deleted)
			continue;

		/* fails if orig_node has no router */
		if (_write_buffer_text(bat_priv, seq, gw_node) < 0)
			continue;

		gw_count++;
	}
	rcu_read_unlock();

	if (gw_count == 0)
		seq_printf(seq, "No gateways in range ...\n");

out:
	if (primary_if)
		hardif_free_ref(primary_if);
	return ret;
}

int gw_is_target(struct bat_priv *bat_priv, struct sk_buff *skb)
{
	struct ethhdr *ethhdr;
	struct iphdr *iphdr;
	struct ipv6hdr *ipv6hdr;
	struct udphdr *udphdr;
	struct gw_node *curr_gw;
	unsigned int header_len = 0;

	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
		return 0;

	/* check for ethernet header */
	if (!pskb_may_pull(skb, header_len + ETH_HLEN))
		return 0;
	ethhdr = (struct ethhdr *)skb->data;
	header_len += ETH_HLEN;

	/* check for initial vlan header */
	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
		if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
			return 0;
		ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
		header_len += VLAN_HLEN;
	}

	/* check for ip header */
	switch (ntohs(ethhdr->h_proto)) {
	case ETH_P_IP:
		if (!pskb_may_pull(skb, header_len + sizeof(*iphdr)))
			return 0;
		iphdr = (struct iphdr *)(skb->data + header_len);
		header_len += iphdr->ihl * 4;

		/* check for udp header */
		if (iphdr->protocol != IPPROTO_UDP)
			return 0;

		break;
	case ETH_P_IPV6:
		if (!pskb_may_pull(skb, header_len + sizeof(*ipv6hdr)))
			return 0;
		ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
		header_len += sizeof(*ipv6hdr);

		/* check for udp header */
		if (ipv6hdr->nexthdr != IPPROTO_UDP)
			return 0;

		break;
	default:
		return 0;
	}

	if (!pskb_may_pull(skb, header_len + sizeof(*udphdr)))
		return 0;
	udphdr = (struct udphdr *)(skb->data + header_len);
	header_len += sizeof(*udphdr);

	/* check for bootp port */
	if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
	     (ntohs(udphdr->dest) != 67))
		return 0;

	if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
	    (ntohs(udphdr->dest) != 547))
		return 0;

	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
		return -1;

	curr_gw = gw_get_selected_gw_node(bat_priv);
	if (!curr_gw)
		return 0;

	if (curr_gw)
		gw_node_free_ref(curr_gw);
	return 1;
}
Commit	Line	Data
c6c8fea2	1	/*
64afe353	2	* Copyright (C) 2009-2011 B.A.T.M.A.N. contributors:
c6c8fea2 SE	3	*
	4	* Marek Lindner
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of version 2 of the GNU General Public
	8	* License as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful, but
	11	* WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	18	* 02110-1301, USA
	19	*
	20	*/
	21
	22	#include "main.h"
2265c141	23	#include "bat_sysfs.h"
c6c8fea2 SE	24	#include "gateway_client.h"
	25	#include "gateway_common.h"
	26	#include "hard-interface.h"
57f0c07c	27	#include "originator.h"
c6c8fea2 SE	28	#include <linux/ip.h>
	29	#include <linux/ipv6.h>
	30	#include <linux/udp.h>
	31	#include <linux/if_vlan.h>
	32
25b6d3c1	33	static void gw_node_free_ref(struct gw_node *gw_node)
c6c8fea2	34	{
25b6d3c1	35	if (atomic_dec_and_test(&gw_node->refcount))
eb340b2f	36	kfree_rcu(gw_node, rcu);
c6c8fea2 SE	37	}
c6c8fea2 SE	38
c4aac1ab	39	static struct gw_node gw_get_selected_gw_node(struct bat_priv bat_priv)
c6c8fea2	40	{
c4aac1ab	41	struct gw_node *gw_node;
c6c8fea2	42
5d02b3cd	43	rcu_read_lock();
c4aac1ab ML	44	gw_node = rcu_dereference(bat_priv->curr_gw);
c4aac1ab ML	45	if (!gw_node)
7b36e8ee	46	goto out;
c6c8fea2	47
c4aac1ab ML	48	if (!atomic_inc_not_zero(&gw_node->refcount))
c4aac1ab ML	49	gw_node = NULL;
43c70ad5	50
5d02b3cd LL	51	out:
5d02b3cd LL	52	rcu_read_unlock();
c4aac1ab	53	return gw_node;
c6c8fea2 SE	54	}
c6c8fea2 SE	55
c4aac1ab	56	struct orig_node gw_get_selected_orig(struct bat_priv bat_priv)
c6c8fea2	57	{
5d02b3cd	58	struct gw_node *gw_node;
c4aac1ab	59	struct orig_node *orig_node = NULL;
c6c8fea2	60
c4aac1ab ML	61	gw_node = gw_get_selected_gw_node(bat_priv);
	62	if (!gw_node)
	63	goto out;
	64
	65	rcu_read_lock();
	66	orig_node = gw_node->orig_node;
	67	if (!orig_node)
	68	goto unlock;
	69
	70	if (!atomic_inc_not_zero(&orig_node->refcount))
	71	orig_node = NULL;
c6c8fea2	72
c4aac1ab ML	73	unlock:
	74	rcu_read_unlock();
	75	out:
c6c8fea2	76	if (gw_node)
25b6d3c1	77	gw_node_free_ref(gw_node);
c4aac1ab	78	return orig_node;
c6c8fea2 SE	79	}
c6c8fea2 SE	80
25b6d3c1	81	static void gw_select(struct bat_priv bat_priv, struct gw_node new_gw_node)
c6c8fea2	82	{
5d02b3cd	83	struct gw_node *curr_gw_node;
c6c8fea2	84
c4aac1ab ML	85	spin_lock_bh(&bat_priv->gw_list_lock);
c4aac1ab ML	86
25b6d3c1 ML	87	if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
25b6d3c1 ML	88	new_gw_node = NULL;
c6c8fea2	89
728cbc6a	90	curr_gw_node = rcu_dereference_protected(bat_priv->curr_gw, 1);
5d02b3cd	91	rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
25b6d3c1 ML	92
	93	if (curr_gw_node)
	94	gw_node_free_ref(curr_gw_node);
c4aac1ab ML	95
	96	spin_unlock_bh(&bat_priv->gw_list_lock);
	97	}
	98
	99	void gw_deselect(struct bat_priv *bat_priv)
	100	{
2265c141	101	atomic_set(&bat_priv->gw_reselect, 1);
c6c8fea2 SE	102	}
c6c8fea2 SE	103
2265c141	104	static struct gw_node gw_get_best_gw_node(struct bat_priv bat_priv)
c6c8fea2	105	{
e1a5382f	106	struct neigh_node *router;
2265c141 AQ	107	struct hlist_node *node;
2265c141 AQ	108	struct gw_node gw_node, curr_gw = NULL;
c6c8fea2	109	uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
2265c141	110	uint8_t max_tq = 0;
c6c8fea2 SE	111	int down, up;
c6c8fea2 SE	112
c4aac1ab	113	rcu_read_lock();
c6c8fea2	114	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
e1a5382f	115	if (gw_node->deleted)
c6c8fea2 SE	116	continue;
c6c8fea2 SE	117
e1a5382f LL	118	router = orig_node_get_router(gw_node->orig_node);
e1a5382f LL	119	if (!router)
c6c8fea2 SE	120	continue;
c6c8fea2 SE	121
2265c141 AQ	122	if (!atomic_inc_not_zero(&gw_node->refcount))
	123	goto next;
	124
c6c8fea2 SE	125	switch (atomic_read(&bat_priv->gw_sel_class)) {
	126	case 1: /* fast connection */
	127	gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
	128	&down, &up);
	129
e1a5382f	130	tmp_gw_factor = (router->tq_avg * router->tq_avg *
c6c8fea2 SE	131	down * 100 * 100) /
	132	(TQ_LOCAL_WINDOW_SIZE *
	133	TQ_LOCAL_WINDOW_SIZE * 64);
	134
	135	if ((tmp_gw_factor > max_gw_factor) \|\|
	136	((tmp_gw_factor == max_gw_factor) &&
2265c141 AQ	137	(router->tq_avg > max_tq))) {
	138	if (curr_gw)
	139	gw_node_free_ref(curr_gw);
	140	curr_gw = gw_node;
	141	atomic_inc(&curr_gw->refcount);
	142	}
c6c8fea2 SE	143	break;
	144
	145	default: /**
	146	* 2: stable connection (use best statistic)
	147	* 3: fast-switch (use best statistic but change as
	148	* soon as a better gateway appears)
	149	* XX: late-switch (use best statistic but change as
	150	* soon as a better gateway appears which has
	151	* $routing_class more tq points)
	152	**/
2265c141 AQ	153	if (router->tq_avg > max_tq) {
	154	if (curr_gw)
	155	gw_node_free_ref(curr_gw);
	156	curr_gw = gw_node;
	157	atomic_inc(&curr_gw->refcount);
	158	}
c6c8fea2 SE	159	break;
	160	}
	161
e1a5382f LL	162	if (router->tq_avg > max_tq)
e1a5382f LL	163	max_tq = router->tq_avg;
c6c8fea2 SE	164
	165	if (tmp_gw_factor > max_gw_factor)
	166	max_gw_factor = tmp_gw_factor;
e1a5382f	167
2265c141 AQ	168	gw_node_free_ref(gw_node);
	169
	170	next:
e1a5382f	171	neigh_node_free_ref(router);
c6c8fea2	172	}
2265c141	173	rcu_read_unlock();
c6c8fea2	174
2265c141 AQ	175	return curr_gw;
2265c141 AQ	176	}
c6c8fea2	177
2265c141 AQ	178	void gw_election(struct bat_priv *bat_priv)
	179	{
	180	struct gw_node curr_gw = NULL, next_gw = NULL;
	181	struct neigh_node *router = NULL;
19595e05	182	char gw_addr[18] = { '\0' };
2265c141 AQ	183
	184	/**
	185	* The batman daemon checks here if we already passed a full originator
	186	* cycle in order to make sure we don't choose the first gateway we
	187	* hear about. This check is based on the daemon's uptime which we
	188	* don't have.
	189	**/
	190	if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
	191	goto out;
	192
	193	if (!atomic_dec_not_zero(&bat_priv->gw_reselect))
	194	goto out;
	195
	196	curr_gw = gw_get_selected_gw_node(bat_priv);
	197
	198	next_gw = gw_get_best_gw_node(bat_priv);
	199
	200	if (curr_gw == next_gw)
	201	goto out;
	202
	203	if (next_gw) {
19595e05 AQ	204	sprintf(gw_addr, "%pM", next_gw->orig_node->orig);
19595e05 AQ	205
2265c141 AQ	206	router = orig_node_get_router(next_gw->orig_node);
	207	if (!router) {
	208	gw_deselect(bat_priv);
	209	goto out;
	210	}
c6c8fea2 SE	211	}
c6c8fea2 SE	212
2265c141 AQ	213	if ((curr_gw) && (!next_gw)) {
	214	bat_dbg(DBG_BATMAN, bat_priv,
	215	"Removing selected gateway - no gateway in range\n");
19595e05	216	throw_uevent(bat_priv, UEV_GW, UEV_DEL, NULL);
2265c141 AQ	217	} else if ((!curr_gw) && (next_gw)) {
	218	bat_dbg(DBG_BATMAN, bat_priv,
	219	"Adding route to gateway %pM (gw_flags: %i, tq: %i)\n",
	220	next_gw->orig_node->orig,
	221	next_gw->orig_node->gw_flags,
	222	router->tq_avg);
19595e05	223	throw_uevent(bat_priv, UEV_GW, UEV_ADD, gw_addr);
2265c141 AQ	224	} else {
	225	bat_dbg(DBG_BATMAN, bat_priv,
	226	"Changing route to gateway %pM "
	227	"(gw_flags: %i, tq: %i)\n",
	228	next_gw->orig_node->orig,
	229	next_gw->orig_node->gw_flags,
	230	router->tq_avg);
19595e05	231	throw_uevent(bat_priv, UEV_GW, UEV_CHANGE, gw_addr);
2265c141 AQ	232	}
	233
	234	gw_select(bat_priv, next_gw);
	235
c4aac1ab ML	236	out:
	237	if (curr_gw)
	238	gw_node_free_ref(curr_gw);
2265c141 AQ	239	if (next_gw)
	240	gw_node_free_ref(next_gw);
	241	if (router)
	242	neigh_node_free_ref(router);
c6c8fea2 SE	243	}
	244
	245	void gw_check_election(struct bat_priv bat_priv, struct orig_node orig_node)
	246	{
57f0c07c	247	struct orig_node *curr_gw_orig;
e1a5382f	248	struct neigh_node router_gw = NULL, router_orig = NULL;
c6c8fea2 SE	249	uint8_t gw_tq_avg, orig_tq_avg;
c6c8fea2 SE	250
c4aac1ab	251	curr_gw_orig = gw_get_selected_orig(bat_priv);
57f0c07c LL	252	if (!curr_gw_orig)
57f0c07c LL	253	goto deselect;
c6c8fea2	254
e1a5382f LL	255	router_gw = orig_node_get_router(curr_gw_orig);
	256	if (!router_gw)
	257	goto deselect;
c6c8fea2 SE	258
c6c8fea2 SE	259	/* this node already is the gateway */
57f0c07c	260	if (curr_gw_orig == orig_node)
e1a5382f	261	goto out;
c6c8fea2	262
e1a5382f LL	263	router_orig = orig_node_get_router(orig_node);
	264	if (!router_orig)
	265	goto out;
5d02b3cd	266
e1a5382f LL	267	gw_tq_avg = router_gw->tq_avg;
e1a5382f LL	268	orig_tq_avg = router_orig->tq_avg;
c6c8fea2 SE	269
	270	/* the TQ value has to be better */
	271	if (orig_tq_avg < gw_tq_avg)
5d02b3cd	272	goto out;
c6c8fea2 SE	273
	274	/**
	275	* if the routing class is greater than 3 the value tells us how much
	276	* greater the TQ value of the new gateway must be
	277	**/
	278	if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
	279	(orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
5d02b3cd	280	goto out;
c6c8fea2 SE	281
	282	bat_dbg(DBG_BATMAN, bat_priv,
	283	"Restarting gateway selection: better gateway found (tq curr: "
	284	"%i, tq new: %i)\n",
	285	gw_tq_avg, orig_tq_avg);
	286
	287	deselect:
	288	gw_deselect(bat_priv);
5d02b3cd	289	out:
57f0c07c LL	290	if (curr_gw_orig)
57f0c07c LL	291	orig_node_free_ref(curr_gw_orig);
e1a5382f LL	292	if (router_gw)
	293	neigh_node_free_ref(router_gw);
	294	if (router_orig)
	295	neigh_node_free_ref(router_orig);
57f0c07c	296
5d02b3cd	297	return;
c6c8fea2 SE	298	}
	299
	300	static void gw_node_add(struct bat_priv *bat_priv,
	301	struct orig_node *orig_node, uint8_t new_gwflags)
	302	{
	303	struct gw_node *gw_node;
	304	int down, up;
	305
704509b8	306	gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
c6c8fea2 SE	307	if (!gw_node)
	308	return;
	309
c6c8fea2 SE	310	INIT_HLIST_NODE(&gw_node->list);
c6c8fea2 SE	311	gw_node->orig_node = orig_node;
25b6d3c1	312	atomic_set(&gw_node->refcount, 1);
c6c8fea2 SE	313
	314	spin_lock_bh(&bat_priv->gw_list_lock);
	315	hlist_add_head_rcu(&gw_node->list, &bat_priv->gw_list);
	316	spin_unlock_bh(&bat_priv->gw_list_lock);
	317
	318	gw_bandwidth_to_kbit(new_gwflags, &down, &up);
	319	bat_dbg(DBG_BATMAN, bat_priv,
	320	"Found new gateway %pM -> gw_class: %i - %i%s/%i%s\n",
	321	orig_node->orig, new_gwflags,
	322	(down > 2048 ? down / 1024 : down),
	323	(down > 2048 ? "MBit" : "KBit"),
	324	(up > 2048 ? up / 1024 : up),
	325	(up > 2048 ? "MBit" : "KBit"));
	326	}
	327
	328	void gw_node_update(struct bat_priv *bat_priv,
	329	struct orig_node *orig_node, uint8_t new_gwflags)
	330	{
	331	struct hlist_node *node;
c4aac1ab ML	332	struct gw_node gw_node, curr_gw;
c4aac1ab ML	333
71e4aa9c AQ	334	/**
	335	* Note: We don't need a NULL check here, since curr_gw never gets
	336	* dereferenced. If curr_gw is NULL we also should not exit as we may
	337	* have this gateway in our list (duplication check!) even though we
	338	* have no currently selected gateway.
	339	*/
c4aac1ab	340	curr_gw = gw_get_selected_gw_node(bat_priv);
c6c8fea2 SE	341
	342	rcu_read_lock();
	343	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
	344	if (gw_node->orig_node != orig_node)
	345	continue;
	346
	347	bat_dbg(DBG_BATMAN, bat_priv,
	348	"Gateway class of originator %pM changed from "
	349	"%i to %i\n",
	350	orig_node->orig, gw_node->orig_node->gw_flags,
	351	new_gwflags);
	352
	353	gw_node->deleted = 0;
	354
ecbd5321	355	if (new_gwflags == NO_FLAGS) {
c6c8fea2 SE	356	gw_node->deleted = jiffies;
	357	bat_dbg(DBG_BATMAN, bat_priv,
	358	"Gateway %pM removed from gateway list\n",
	359	orig_node->orig);
	360
c4aac1ab ML	361	if (gw_node == curr_gw)
c4aac1ab ML	362	goto deselect;
c6c8fea2 SE	363	}
c6c8fea2 SE	364
c4aac1ab	365	goto unlock;
c6c8fea2	366	}
c6c8fea2	367
ecbd5321	368	if (new_gwflags == NO_FLAGS)
c4aac1ab	369	goto unlock;
c6c8fea2 SE	370
c6c8fea2 SE	371	gw_node_add(bat_priv, orig_node, new_gwflags);
c4aac1ab ML	372	goto unlock;
	373
	374	deselect:
	375	gw_deselect(bat_priv);
	376	unlock:
	377	rcu_read_unlock();
71e4aa9c	378
c4aac1ab ML	379	if (curr_gw)
c4aac1ab ML	380	gw_node_free_ref(curr_gw);
c6c8fea2 SE	381	}
	382
	383	void gw_node_delete(struct bat_priv bat_priv, struct orig_node orig_node)
	384	{
6b9aadfa	385	gw_node_update(bat_priv, orig_node, 0);
c6c8fea2 SE	386	}
	387
	388	void gw_node_purge(struct bat_priv *bat_priv)
	389	{
c4aac1ab	390	struct gw_node gw_node, curr_gw;
c6c8fea2 SE	391	struct hlist_node node, node_tmp;
c6c8fea2 SE	392	unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
b4e17054	393	int do_deselect = 0;
c4aac1ab ML	394
c4aac1ab ML	395	curr_gw = gw_get_selected_gw_node(bat_priv);
c6c8fea2 SE	396
	397	spin_lock_bh(&bat_priv->gw_list_lock);
	398
	399	hlist_for_each_entry_safe(gw_node, node, node_tmp,
	400	&bat_priv->gw_list, list) {
	401	if (((!gw_node->deleted) \|\|
	402	(time_before(jiffies, gw_node->deleted + timeout))) &&
	403	atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
	404	continue;
	405
c4aac1ab ML	406	if (curr_gw == gw_node)
c4aac1ab ML	407	do_deselect = 1;
c6c8fea2 SE	408
c6c8fea2 SE	409	hlist_del_rcu(&gw_node->list);
25b6d3c1	410	gw_node_free_ref(gw_node);
c6c8fea2 SE	411	}
c6c8fea2 SE	412
c6c8fea2	413	spin_unlock_bh(&bat_priv->gw_list_lock);
c4aac1ab ML	414
	415	/* gw_deselect() needs to acquire the gw_list_lock */
	416	if (do_deselect)
	417	gw_deselect(bat_priv);
	418
	419	if (curr_gw)
	420	gw_node_free_ref(curr_gw);
c6c8fea2 SE	421	}
c6c8fea2 SE	422
e1a5382f LL	423	/**
	424	* fails if orig_node has no router
	425	*/
747e4221 SE	426	static int _write_buffer_text(struct bat_priv bat_priv, struct seq_file seq,
747e4221 SE	427	const struct gw_node *gw_node)
c6c8fea2	428	{
5d02b3cd	429	struct gw_node *curr_gw;
e1a5382f LL	430	struct neigh_node *router;
e1a5382f LL	431	int down, up, ret = -1;
c6c8fea2 SE	432
	433	gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
	434
e1a5382f LL	435	router = orig_node_get_router(gw_node->orig_node);
	436	if (!router)
	437	goto out;
5d02b3cd	438
c4aac1ab	439	curr_gw = gw_get_selected_gw_node(bat_priv);
5d02b3cd	440
5d02b3cd	441	ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
c4aac1ab ML	442	(curr_gw == gw_node ? "=>" : " "),
	443	gw_node->orig_node->orig,
	444	router->tq_avg, router->addr,
	445	router->if_incoming->net_dev->name,
	446	gw_node->orig_node->gw_flags,
	447	(down > 2048 ? down / 1024 : down),
	448	(down > 2048 ? "MBit" : "KBit"),
	449	(up > 2048 ? up / 1024 : up),
	450	(up > 2048 ? "MBit" : "KBit"));
5d02b3cd	451
e1a5382f	452	neigh_node_free_ref(router);
c4aac1ab ML	453	if (curr_gw)
c4aac1ab ML	454	gw_node_free_ref(curr_gw);
e1a5382f	455	out:
5d02b3cd	456	return ret;
c6c8fea2 SE	457	}
	458
	459	int gw_client_seq_print_text(struct seq_file seq, void offset)
	460	{
	461	struct net_device net_dev = (struct net_device )seq->private;
	462	struct bat_priv *bat_priv = netdev_priv(net_dev);
32ae9b22	463	struct hard_iface *primary_if;
c6c8fea2 SE	464	struct gw_node *gw_node;
c6c8fea2 SE	465	struct hlist_node *node;
32ae9b22	466	int gw_count = 0, ret = 0;
c6c8fea2	467
32ae9b22 ML	468	primary_if = primary_if_get_selected(bat_priv);
	469	if (!primary_if) {
	470	ret = seq_printf(seq, "BATMAN mesh %s disabled - please "
	471	"specify interfaces to enable it\n",
	472	net_dev->name);
	473	goto out;
c6c8fea2 SE	474	}
c6c8fea2 SE	475
32ae9b22 ML	476	if (primary_if->if_status != IF_ACTIVE) {
	477	ret = seq_printf(seq, "BATMAN mesh %s disabled - "
	478	"primary interface not active\n",
	479	net_dev->name);
	480	goto out;
c6c8fea2 SE	481	}
	482
	483	seq_printf(seq, " %-12s (%s/%i) %17s [%10s]: gw_class ... "
	484	"[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
	485	"Gateway", "#", TQ_MAX_VALUE, "Nexthop",
	486	"outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR,
32ae9b22 ML	487	primary_if->net_dev->name,
32ae9b22 ML	488	primary_if->net_dev->dev_addr, net_dev->name);
c6c8fea2 SE	489
	490	rcu_read_lock();
	491	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
	492	if (gw_node->deleted)
	493	continue;
	494
e1a5382f LL	495	/* fails if orig_node has no router */
e1a5382f LL	496	if (_write_buffer_text(bat_priv, seq, gw_node) < 0)
c6c8fea2 SE	497	continue;
c6c8fea2 SE	498
c6c8fea2 SE	499	gw_count++;
	500	}
	501	rcu_read_unlock();
	502
	503	if (gw_count == 0)
	504	seq_printf(seq, "No gateways in range ...\n");
	505
32ae9b22 ML	506	out:
	507	if (primary_if)
	508	hardif_free_ref(primary_if);
	509	return ret;
c6c8fea2 SE	510	}
	511
	512	int gw_is_target(struct bat_priv bat_priv, struct sk_buff skb)
	513	{
	514	struct ethhdr *ethhdr;
	515	struct iphdr *iphdr;
	516	struct ipv6hdr *ipv6hdr;
	517	struct udphdr *udphdr;
c4aac1ab	518	struct gw_node *curr_gw;
c6c8fea2 SE	519	unsigned int header_len = 0;
	520
	521	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
	522	return 0;
	523
	524	/* check for ethernet header */
	525	if (!pskb_may_pull(skb, header_len + ETH_HLEN))
	526	return 0;
	527	ethhdr = (struct ethhdr *)skb->data;
	528	header_len += ETH_HLEN;
	529
	530	/* check for initial vlan header */
	531	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
	532	if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
	533	return 0;
	534	ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
	535	header_len += VLAN_HLEN;
	536	}
	537
	538	/* check for ip header */
	539	switch (ntohs(ethhdr->h_proto)) {
	540	case ETH_P_IP:
704509b8	541	if (!pskb_may_pull(skb, header_len + sizeof(*iphdr)))
c6c8fea2 SE	542	return 0;
	543	iphdr = (struct iphdr *)(skb->data + header_len);
	544	header_len += iphdr->ihl * 4;
	545
	546	/* check for udp header */
	547	if (iphdr->protocol != IPPROTO_UDP)
	548	return 0;
	549
	550	break;
	551	case ETH_P_IPV6:
704509b8	552	if (!pskb_may_pull(skb, header_len + sizeof(*ipv6hdr)))
c6c8fea2 SE	553	return 0;
c6c8fea2 SE	554	ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
704509b8	555	header_len += sizeof(*ipv6hdr);
c6c8fea2 SE	556
	557	/* check for udp header */
	558	if (ipv6hdr->nexthdr != IPPROTO_UDP)
	559	return 0;
	560
	561	break;
	562	default:
	563	return 0;
	564	}
	565
704509b8	566	if (!pskb_may_pull(skb, header_len + sizeof(*udphdr)))
c6c8fea2 SE	567	return 0;
c6c8fea2 SE	568	udphdr = (struct udphdr *)(skb->data + header_len);
704509b8	569	header_len += sizeof(*udphdr);
c6c8fea2 SE	570
	571	/* check for bootp port */
	572	if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
	573	(ntohs(udphdr->dest) != 67))
	574	return 0;
	575
	576	if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
	577	(ntohs(udphdr->dest) != 547))
	578	return 0;
	579
	580	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
	581	return -1;
	582
c4aac1ab ML	583	curr_gw = gw_get_selected_gw_node(bat_priv);
c4aac1ab ML	584	if (!curr_gw)
c6c8fea2 SE	585	return 0;
c6c8fea2 SE	586
c4aac1ab ML	587	if (curr_gw)
c4aac1ab ML	588	gw_node_free_ref(curr_gw);
c6c8fea2 SE	589	return 1;
c6c8fea2 SE	590	}