[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 "gateway_client.h"
#include "gateway_common.h"
#include "hard-interface.h"
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/udp.h>
#include <linux/if_vlan.h>

static void gw_node_free_rcu(struct rcu_head *rcu)
{
	struct gw_node *gw_node;

	gw_node = container_of(rcu, struct gw_node, rcu);
	kfree(gw_node);
}

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

void *gw_get_selected(struct bat_priv *bat_priv)
{
	struct gw_node *curr_gateway_tmp;
	struct orig_node *orig_node = NULL;

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

	orig_node = curr_gateway_tmp->orig_node;

out:
	rcu_read_unlock();
	return orig_node;
}

void gw_deselect(struct bat_priv *bat_priv)
{
	struct gw_node *gw_node;

	spin_lock_bh(&bat_priv->gw_list_lock);
	gw_node = rcu_dereference(bat_priv->curr_gw);
	rcu_assign_pointer(bat_priv->curr_gw, NULL);
	spin_unlock_bh(&bat_priv->gw_list_lock);

	if (gw_node)
		gw_node_free_ref(gw_node);
}

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

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

	spin_lock_bh(&bat_priv->gw_list_lock);
	curr_gw_node = rcu_dereference(bat_priv->curr_gw);
	rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
	spin_unlock_bh(&bat_priv->gw_list_lock);

	if (curr_gw_node)
		gw_node_free_ref(curr_gw_node);
}

void gw_election(struct bat_priv *bat_priv)
{
	struct hlist_node *node;
	struct gw_node *gw_node, *curr_gw, *curr_gw_tmp = NULL;
	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;

	rcu_read_lock();
	curr_gw = rcu_dereference(bat_priv->curr_gw);
	if (curr_gw) {
		rcu_read_unlock();
		return;
	}

	if (hlist_empty(&bat_priv->gw_list)) {

		if (curr_gw) {
			rcu_read_unlock();
			bat_dbg(DBG_BATMAN, bat_priv,
				"Removing selected gateway - "
				"no gateway in range\n");
			gw_deselect(bat_priv);
		} else
			rcu_read_unlock();

		return;
	}

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

		if (gw_node->deleted)
			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 = (gw_node->orig_node->router->tq_avg *
					 gw_node->orig_node->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) &&
			     (gw_node->orig_node->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 (gw_node->orig_node->router->tq_avg > max_tq)
				curr_gw_tmp = gw_node;
			break;
		}

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

		if (tmp_gw_factor > max_gw_factor)
			max_gw_factor = tmp_gw_factor;
	}

	if (curr_gw != curr_gw_tmp) {
		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,
				curr_gw_tmp->orig_node->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,
				curr_gw_tmp->orig_node->router->tq_avg);

		gw_select(bat_priv, curr_gw_tmp);
	}

	rcu_read_unlock();
}

void gw_check_election(struct bat_priv *bat_priv, struct orig_node *orig_node)
{
	struct gw_node *curr_gateway_tmp;
	uint8_t gw_tq_avg, orig_tq_avg;

	rcu_read_lock();
	curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
	if (!curr_gateway_tmp)
		goto out_rcu;

	if (!curr_gateway_tmp->orig_node)
		goto deselect_rcu;

	if (!curr_gateway_tmp->orig_node->router)
		goto deselect_rcu;

	/* this node already is the gateway */
	if (curr_gateway_tmp->orig_node == orig_node)
		goto out_rcu;

	if (!orig_node->router)
		goto out_rcu;

	gw_tq_avg = curr_gateway_tmp->orig_node->router->tq_avg;
	rcu_read_unlock();

	orig_tq_avg = orig_node->router->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);
	goto deselect;

out_rcu:
	rcu_read_unlock();
	goto out;
deselect_rcu:
	rcu_read_unlock();
deselect:
	gw_deselect(bat_priv);
out:
	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 = kmalloc(sizeof(struct gw_node), GFP_ATOMIC);
	if (!gw_node)
		return;

	memset(gw_node, 0, sizeof(struct gw_node));
	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;

	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 == 0) {
			gw_node->deleted = jiffies;
			bat_dbg(DBG_BATMAN, bat_priv,
				"Gateway %pM removed from gateway list\n",
				orig_node->orig);

			if (gw_node == rcu_dereference(bat_priv->curr_gw)) {
				rcu_read_unlock();
				gw_deselect(bat_priv);
				return;
			}
		}

		rcu_read_unlock();
		return;
	}
	rcu_read_unlock();

	if (new_gwflags == 0)
		return;

	gw_node_add(bat_priv, orig_node, new_gwflags);
}

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

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

	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 (rcu_dereference(bat_priv->curr_gw) == gw_node)
			gw_deselect(bat_priv);

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


	spin_unlock_bh(&bat_priv->gw_list_lock);
}

static int _write_buffer_text(struct bat_priv *bat_priv,
			      struct seq_file *seq, struct gw_node *gw_node)
{
	struct gw_node *curr_gw;
	int down, up, ret;

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

	rcu_read_lock();
	curr_gw = rcu_dereference(bat_priv->curr_gw);

	ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
		       (curr_gw == gw_node ? "=>" : "  "),
		       gw_node->orig_node->orig,
		       gw_node->orig_node->router->tq_avg,
		       gw_node->orig_node->router->addr,
		       gw_node->orig_node->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"));

	rcu_read_unlock();
	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 gw_node *gw_node;
	struct hlist_node *node;
	int gw_count = 0;

	if (!bat_priv->primary_if) {

		return seq_printf(seq, "BATMAN mesh %s disabled - please "
				  "specify interfaces to enable it\n",
				  net_dev->name);
	}

	if (bat_priv->primary_if->if_status != IF_ACTIVE) {

		return seq_printf(seq, "BATMAN mesh %s disabled - "
				       "primary interface not active\n",
				       net_dev->name);
	}

	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,
		   bat_priv->primary_if->net_dev->name,
		   bat_priv->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;

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

		_write_buffer_text(bat_priv, seq, gw_node);
		gw_count++;
	}
	rcu_read_unlock();

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

	return 0;
}

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;
	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(struct 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(struct ipv6hdr)))
			return 0;
		ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
		header_len += sizeof(struct ipv6hdr);

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

		break;
	default:
		return 0;
	}

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

	rcu_read_lock();
	if (!rcu_dereference(bat_priv->curr_gw)) {
		rcu_read_unlock();
		return 0;
	}
	rcu_read_unlock();

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