[mirror_ubuntu-zesty-kernel.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 "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)
{
	gw_select(bat_priv, NULL);
}

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

	/**
	 * 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)
		return;

	curr_gw = gw_get_selected_gw_node(bat_priv);
	if (curr_gw)
		goto out;

	rcu_read_lock();
	if (hlist_empty(&bat_priv->gw_list)) {
		bat_dbg(DBG_BATMAN, bat_priv,
			"Removing selected gateway - "
			"no gateway in range\n");
		gw_deselect(bat_priv);
		goto unlock;
	}

	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;

		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)))
				curr_gw_tmp = gw_node;
			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)
				curr_gw_tmp = gw_node;
			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;

		neigh_node_free_ref(router);
	}

	if (curr_gw != curr_gw_tmp) {
		router = orig_node_get_router(curr_gw_tmp->orig_node);
		if (!router)
			goto unlock;

		if ((curr_gw) && (!curr_gw_tmp))
			bat_dbg(DBG_BATMAN, bat_priv,
				"Removing selected gateway - "
				"no gateway in range\n");
		else if ((!curr_gw) && (curr_gw_tmp))
			bat_dbg(DBG_BATMAN, bat_priv,
				"Adding route to gateway %pM "
				"(gw_flags: %i, tq: %i)\n",
				curr_gw_tmp->orig_node->orig,
				curr_gw_tmp->orig_node->gw_flags,
				router->tq_avg);
		else
			bat_dbg(DBG_BATMAN, bat_priv,
				"Changing route to gateway %pM "
				"(gw_flags: %i, tq: %i)\n",
				curr_gw_tmp->orig_node->orig,
				curr_gw_tmp->orig_node->gw_flags,
				router->tq_avg);

		neigh_node_free_ref(router);
		gw_select(bat_priv, curr_gw_tmp);
	}

unlock:
	rcu_read_unlock();
out:
	if (curr_gw)
		gw_node_free_ref(curr_gw);
}

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