[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 "originator.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);
}

struct orig_node *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;
	if (!orig_node)
		goto out;

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

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;
	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;

	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->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 out;

		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);
	}

out:
	rcu_read_unlock();
}

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(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 = 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);
}

/**
 * fails if orig_node has no router
 */
static int _write_buffer_text(struct bat_priv *bat_priv,
			      struct seq_file *seq, 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;

	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,
		       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"));

	rcu_read_unlock();
	neigh_node_free_ref(router);
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 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;

		/* 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");

	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"
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_rcu(struct rcu_head *rcu)
c6c8fea2 SE	33	{
	34	struct gw_node *gw_node;
	35
25b6d3c1	36	gw_node = container_of(rcu, struct gw_node, rcu);
c6c8fea2 SE	37	kfree(gw_node);
	38	}
	39
25b6d3c1	40	static void gw_node_free_ref(struct gw_node *gw_node)
c6c8fea2	41	{
25b6d3c1 ML	42	if (atomic_dec_and_test(&gw_node->refcount))
25b6d3c1 ML	43	call_rcu(&gw_node->rcu, gw_node_free_rcu);
c6c8fea2 SE	44	}
c6c8fea2 SE	45
4c804850	46	struct orig_node gw_get_selected(struct bat_priv bat_priv)
c6c8fea2	47	{
5d02b3cd LL	48	struct gw_node *curr_gateway_tmp;
5d02b3cd LL	49	struct orig_node *orig_node = NULL;
c6c8fea2	50
5d02b3cd LL	51	rcu_read_lock();
5d02b3cd LL	52	curr_gateway_tmp = rcu_dereference(bat_priv->curr_gw);
c6c8fea2	53	if (!curr_gateway_tmp)
5d02b3cd LL	54	goto out;
	55
	56	orig_node = curr_gateway_tmp->orig_node;
7b36e8ee ML	57	if (!orig_node)
7b36e8ee ML	58	goto out;
c6c8fea2	59
7b36e8ee ML	60	if (!atomic_inc_not_zero(&orig_node->refcount))
7b36e8ee ML	61	orig_node = NULL;
43c70ad5	62
5d02b3cd LL	63	out:
	64	rcu_read_unlock();
	65	return orig_node;
c6c8fea2 SE	66	}
	67
	68	void gw_deselect(struct bat_priv *bat_priv)
	69	{
5d02b3cd	70	struct gw_node *gw_node;
c6c8fea2	71
5d02b3cd LL	72	spin_lock_bh(&bat_priv->gw_list_lock);
	73	gw_node = rcu_dereference(bat_priv->curr_gw);
	74	rcu_assign_pointer(bat_priv->curr_gw, NULL);
	75	spin_unlock_bh(&bat_priv->gw_list_lock);
c6c8fea2 SE	76
c6c8fea2 SE	77	if (gw_node)
25b6d3c1	78	gw_node_free_ref(gw_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
25b6d3c1 ML	85	if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
25b6d3c1 ML	86	new_gw_node = NULL;
c6c8fea2	87
5d02b3cd LL	88	spin_lock_bh(&bat_priv->gw_list_lock);
	89	curr_gw_node = rcu_dereference(bat_priv->curr_gw);
	90	rcu_assign_pointer(bat_priv->curr_gw, new_gw_node);
	91	spin_unlock_bh(&bat_priv->gw_list_lock);
25b6d3c1 ML	92
	93	if (curr_gw_node)
	94	gw_node_free_ref(curr_gw_node);
c6c8fea2 SE	95	}
	96
	97	void gw_election(struct bat_priv *bat_priv)
	98	{
	99	struct hlist_node *node;
5d02b3cd	100	struct gw_node gw_node, curr_gw, *curr_gw_tmp = NULL;
e1a5382f	101	struct neigh_node *router;
c6c8fea2 SE	102	uint8_t max_tq = 0;
	103	uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
	104	int down, up;
	105
	106	/**
	107	* The batman daemon checks here if we already passed a full originator
	108	* cycle in order to make sure we don't choose the first gateway we
	109	* hear about. This check is based on the daemon's uptime which we
	110	* don't have.
	111	**/
	112	if (atomic_read(&bat_priv->gw_mode) != GW_MODE_CLIENT)
	113	return;
	114
5d02b3cd LL	115	rcu_read_lock();
	116	curr_gw = rcu_dereference(bat_priv->curr_gw);
	117	if (curr_gw) {
	118	rcu_read_unlock();
c6c8fea2	119	return;
5d02b3cd	120	}
c6c8fea2	121
c6c8fea2	122	if (hlist_empty(&bat_priv->gw_list)) {
c6c8fea2	123
5d02b3cd LL	124	if (curr_gw) {
5d02b3cd LL	125	rcu_read_unlock();
c6c8fea2 SE	126	bat_dbg(DBG_BATMAN, bat_priv,
	127	"Removing selected gateway - "
	128	"no gateway in range\n");
	129	gw_deselect(bat_priv);
5d02b3cd LL	130	} else
5d02b3cd LL	131	rcu_read_unlock();
c6c8fea2 SE	132
	133	return;
	134	}
	135
	136	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
e1a5382f	137	if (gw_node->deleted)
c6c8fea2 SE	138	continue;
c6c8fea2 SE	139
e1a5382f LL	140	router = orig_node_get_router(gw_node->orig_node);
e1a5382f LL	141	if (!router)
c6c8fea2 SE	142	continue;
	143
	144	switch (atomic_read(&bat_priv->gw_sel_class)) {
	145	case 1: /* fast connection */
	146	gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags,
	147	&down, &up);
	148
e1a5382f	149	tmp_gw_factor = (router->tq_avg * router->tq_avg *
c6c8fea2 SE	150	down * 100 * 100) /
	151	(TQ_LOCAL_WINDOW_SIZE *
	152	TQ_LOCAL_WINDOW_SIZE * 64);
	153
	154	if ((tmp_gw_factor > max_gw_factor) \|\|
	155	((tmp_gw_factor == max_gw_factor) &&
e1a5382f	156	(router->tq_avg > max_tq)))
c6c8fea2 SE	157	curr_gw_tmp = gw_node;
	158	break;
	159
	160	default: /**
	161	* 2: stable connection (use best statistic)
	162	* 3: fast-switch (use best statistic but change as
	163	* soon as a better gateway appears)
	164	* XX: late-switch (use best statistic but change as
	165	* soon as a better gateway appears which has
	166	* $routing_class more tq points)
	167	**/
e1a5382f	168	if (router->tq_avg > max_tq)
c6c8fea2 SE	169	curr_gw_tmp = gw_node;
	170	break;
	171	}
	172
e1a5382f LL	173	if (router->tq_avg > max_tq)
e1a5382f LL	174	max_tq = router->tq_avg;
c6c8fea2 SE	175
	176	if (tmp_gw_factor > max_gw_factor)
	177	max_gw_factor = tmp_gw_factor;
e1a5382f LL	178
e1a5382f LL	179	neigh_node_free_ref(router);
c6c8fea2 SE	180	}
c6c8fea2 SE	181
5d02b3cd	182	if (curr_gw != curr_gw_tmp) {
e1a5382f LL	183	router = orig_node_get_router(curr_gw_tmp->orig_node);
	184	if (!router)
	185	goto out;
	186
5d02b3cd	187	if ((curr_gw) && (!curr_gw_tmp))
c6c8fea2 SE	188	bat_dbg(DBG_BATMAN, bat_priv,
	189	"Removing selected gateway - "
	190	"no gateway in range\n");
5d02b3cd	191	else if ((!curr_gw) && (curr_gw_tmp))
c6c8fea2 SE	192	bat_dbg(DBG_BATMAN, bat_priv,
	193	"Adding route to gateway %pM "
	194	"(gw_flags: %i, tq: %i)\n",
	195	curr_gw_tmp->orig_node->orig,
	196	curr_gw_tmp->orig_node->gw_flags,
e1a5382f	197	router->tq_avg);
c6c8fea2 SE	198	else
	199	bat_dbg(DBG_BATMAN, bat_priv,
	200	"Changing route to gateway %pM "
	201	"(gw_flags: %i, tq: %i)\n",
	202	curr_gw_tmp->orig_node->orig,
	203	curr_gw_tmp->orig_node->gw_flags,
e1a5382f	204	router->tq_avg);
c6c8fea2	205
e1a5382f	206	neigh_node_free_ref(router);
25b6d3c1	207	gw_select(bat_priv, curr_gw_tmp);
c6c8fea2 SE	208	}
c6c8fea2 SE	209
e1a5382f	210	out:
c6c8fea2	211	rcu_read_unlock();
c6c8fea2 SE	212	}
	213
	214	void gw_check_election(struct bat_priv bat_priv, struct orig_node orig_node)
	215	{
57f0c07c	216	struct orig_node *curr_gw_orig;
e1a5382f	217	struct neigh_node router_gw = NULL, router_orig = NULL;
c6c8fea2 SE	218	uint8_t gw_tq_avg, orig_tq_avg;
c6c8fea2 SE	219
57f0c07c LL	220	curr_gw_orig = gw_get_selected(bat_priv);
	221	if (!curr_gw_orig)
	222	goto deselect;
c6c8fea2	223
e1a5382f LL	224	router_gw = orig_node_get_router(curr_gw_orig);
	225	if (!router_gw)
	226	goto deselect;
c6c8fea2 SE	227
c6c8fea2 SE	228	/* this node already is the gateway */
57f0c07c	229	if (curr_gw_orig == orig_node)
e1a5382f	230	goto out;
c6c8fea2	231
e1a5382f LL	232	router_orig = orig_node_get_router(orig_node);
	233	if (!router_orig)
	234	goto out;
5d02b3cd	235
e1a5382f LL	236	gw_tq_avg = router_gw->tq_avg;
e1a5382f LL	237	orig_tq_avg = router_orig->tq_avg;
c6c8fea2 SE	238
	239	/* the TQ value has to be better */
	240	if (orig_tq_avg < gw_tq_avg)
5d02b3cd	241	goto out;
c6c8fea2 SE	242
	243	/**
	244	* if the routing class is greater than 3 the value tells us how much
	245	* greater the TQ value of the new gateway must be
	246	**/
	247	if ((atomic_read(&bat_priv->gw_sel_class) > 3) &&
	248	(orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw_sel_class)))
5d02b3cd	249	goto out;
c6c8fea2 SE	250
	251	bat_dbg(DBG_BATMAN, bat_priv,
	252	"Restarting gateway selection: better gateway found (tq curr: "
	253	"%i, tq new: %i)\n",
	254	gw_tq_avg, orig_tq_avg);
	255
	256	deselect:
	257	gw_deselect(bat_priv);
5d02b3cd	258	out:
57f0c07c LL	259	if (curr_gw_orig)
57f0c07c LL	260	orig_node_free_ref(curr_gw_orig);
e1a5382f LL	261	if (router_gw)
	262	neigh_node_free_ref(router_gw);
	263	if (router_orig)
	264	neigh_node_free_ref(router_orig);
57f0c07c	265
5d02b3cd	266	return;
c6c8fea2 SE	267	}
	268
	269	static void gw_node_add(struct bat_priv *bat_priv,
	270	struct orig_node *orig_node, uint8_t new_gwflags)
	271	{
	272	struct gw_node *gw_node;
	273	int down, up;
	274
	275	gw_node = kmalloc(sizeof(struct gw_node), GFP_ATOMIC);
	276	if (!gw_node)
	277	return;
	278
	279	memset(gw_node, 0, sizeof(struct gw_node));
	280	INIT_HLIST_NODE(&gw_node->list);
	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;
	302	struct gw_node *gw_node;
	303
	304	rcu_read_lock();
	305	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
	306	if (gw_node->orig_node != orig_node)
	307	continue;
	308
	309	bat_dbg(DBG_BATMAN, bat_priv,
	310	"Gateway class of originator %pM changed from "
	311	"%i to %i\n",
	312	orig_node->orig, gw_node->orig_node->gw_flags,
	313	new_gwflags);
	314
	315	gw_node->deleted = 0;
	316
	317	if (new_gwflags == 0) {
	318	gw_node->deleted = jiffies;
	319	bat_dbg(DBG_BATMAN, bat_priv,
	320	"Gateway %pM removed from gateway list\n",
	321	orig_node->orig);
	322
5d02b3cd	323	if (gw_node == rcu_dereference(bat_priv->curr_gw)) {
c6c8fea2 SE	324	rcu_read_unlock();
	325	gw_deselect(bat_priv);
	326	return;
	327	}
	328	}
	329
	330	rcu_read_unlock();
	331	return;
	332	}
	333	rcu_read_unlock();
	334
	335	if (new_gwflags == 0)
	336	return;
	337
	338	gw_node_add(bat_priv, orig_node, new_gwflags);
	339	}
	340
	341	void gw_node_delete(struct bat_priv bat_priv, struct orig_node orig_node)
	342	{
	343	return gw_node_update(bat_priv, orig_node, 0);
	344	}
	345
	346	void gw_node_purge(struct bat_priv *bat_priv)
	347	{
	348	struct gw_node *gw_node;
	349	struct hlist_node node, node_tmp;
	350	unsigned long timeout = 2 * PURGE_TIMEOUT * HZ;
	351
	352	spin_lock_bh(&bat_priv->gw_list_lock);
	353
	354	hlist_for_each_entry_safe(gw_node, node, node_tmp,
	355	&bat_priv->gw_list, list) {
	356	if (((!gw_node->deleted) \|\|
	357	(time_before(jiffies, gw_node->deleted + timeout))) &&
	358	atomic_read(&bat_priv->mesh_state) == MESH_ACTIVE)
	359	continue;
	360
5d02b3cd	361	if (rcu_dereference(bat_priv->curr_gw) == gw_node)
c6c8fea2 SE	362	gw_deselect(bat_priv);
	363
	364	hlist_del_rcu(&gw_node->list);
25b6d3c1	365	gw_node_free_ref(gw_node);
c6c8fea2 SE	366	}
	367
	368
	369	spin_unlock_bh(&bat_priv->gw_list_lock);
	370	}
	371
e1a5382f LL	372	/**
	373	* fails if orig_node has no router
	374	*/
c6c8fea2 SE	375	static int _write_buffer_text(struct bat_priv *bat_priv,
	376	struct seq_file seq, struct gw_node gw_node)
	377	{
5d02b3cd	378	struct gw_node *curr_gw;
e1a5382f LL	379	struct neigh_node *router;
e1a5382f LL	380	int down, up, ret = -1;
c6c8fea2 SE	381
	382	gw_bandwidth_to_kbit(gw_node->orig_node->gw_flags, &down, &up);
	383
e1a5382f LL	384	router = orig_node_get_router(gw_node->orig_node);
	385	if (!router)
	386	goto out;
	387
5d02b3cd LL	388	rcu_read_lock();
	389	curr_gw = rcu_dereference(bat_priv->curr_gw);
	390
	391	ret = seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %3i - %i%s/%i%s\n",
	392	(curr_gw == gw_node ? "=>" : " "),
c6c8fea2	393	gw_node->orig_node->orig,
e1a5382f LL	394	router->tq_avg, router->addr,
e1a5382f LL	395	router->if_incoming->net_dev->name,
c6c8fea2 SE	396	gw_node->orig_node->gw_flags,
	397	(down > 2048 ? down / 1024 : down),
	398	(down > 2048 ? "MBit" : "KBit"),
	399	(up > 2048 ? up / 1024 : up),
	400	(up > 2048 ? "MBit" : "KBit"));
5d02b3cd LL	401
5d02b3cd LL	402	rcu_read_unlock();
e1a5382f LL	403	neigh_node_free_ref(router);
e1a5382f LL	404	out:
5d02b3cd	405	return ret;
c6c8fea2 SE	406	}
	407
	408	int gw_client_seq_print_text(struct seq_file seq, void offset)
	409	{
	410	struct net_device net_dev = (struct net_device )seq->private;
	411	struct bat_priv *bat_priv = netdev_priv(net_dev);
	412	struct gw_node *gw_node;
	413	struct hlist_node *node;
	414	int gw_count = 0;
	415
	416	if (!bat_priv->primary_if) {
	417
	418	return seq_printf(seq, "BATMAN mesh %s disabled - please "
	419	"specify interfaces to enable it\n",
	420	net_dev->name);
	421	}
	422
	423	if (bat_priv->primary_if->if_status != IF_ACTIVE) {
	424
	425	return seq_printf(seq, "BATMAN mesh %s disabled - "
	426	"primary interface not active\n",
	427	net_dev->name);
	428	}
	429
	430	seq_printf(seq, " %-12s (%s/%i) %17s [%10s]: gw_class ... "
	431	"[B.A.T.M.A.N. adv %s%s, MainIF/MAC: %s/%pM (%s)]\n",
	432	"Gateway", "#", TQ_MAX_VALUE, "Nexthop",
	433	"outgoingIF", SOURCE_VERSION, REVISION_VERSION_STR,
	434	bat_priv->primary_if->net_dev->name,
	435	bat_priv->primary_if->net_dev->dev_addr, net_dev->name);
	436
	437	rcu_read_lock();
	438	hlist_for_each_entry_rcu(gw_node, node, &bat_priv->gw_list, list) {
	439	if (gw_node->deleted)
	440	continue;
	441
e1a5382f LL	442	/* fails if orig_node has no router */
e1a5382f LL	443	if (_write_buffer_text(bat_priv, seq, gw_node) < 0)
c6c8fea2 SE	444	continue;
c6c8fea2 SE	445
c6c8fea2 SE	446	gw_count++;
	447	}
	448	rcu_read_unlock();
	449
	450	if (gw_count == 0)
	451	seq_printf(seq, "No gateways in range ...\n");
	452
	453	return 0;
	454	}
	455
	456	int gw_is_target(struct bat_priv bat_priv, struct sk_buff skb)
	457	{
	458	struct ethhdr *ethhdr;
	459	struct iphdr *iphdr;
	460	struct ipv6hdr *ipv6hdr;
	461	struct udphdr *udphdr;
	462	unsigned int header_len = 0;
	463
	464	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_OFF)
	465	return 0;
	466
	467	/* check for ethernet header */
	468	if (!pskb_may_pull(skb, header_len + ETH_HLEN))
	469	return 0;
	470	ethhdr = (struct ethhdr *)skb->data;
	471	header_len += ETH_HLEN;
	472
	473	/* check for initial vlan header */
	474	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
	475	if (!pskb_may_pull(skb, header_len + VLAN_HLEN))
	476	return 0;
	477	ethhdr = (struct ethhdr *)(skb->data + VLAN_HLEN);
	478	header_len += VLAN_HLEN;
	479	}
	480
	481	/* check for ip header */
	482	switch (ntohs(ethhdr->h_proto)) {
	483	case ETH_P_IP:
	484	if (!pskb_may_pull(skb, header_len + sizeof(struct iphdr)))
	485	return 0;
	486	iphdr = (struct iphdr *)(skb->data + header_len);
	487	header_len += iphdr->ihl * 4;
	488
	489	/* check for udp header */
	490	if (iphdr->protocol != IPPROTO_UDP)
	491	return 0;
	492
	493	break;
	494	case ETH_P_IPV6:
	495	if (!pskb_may_pull(skb, header_len + sizeof(struct ipv6hdr)))
	496	return 0;
	497	ipv6hdr = (struct ipv6hdr *)(skb->data + header_len);
	498	header_len += sizeof(struct ipv6hdr);
	499
	500	/* check for udp header */
	501	if (ipv6hdr->nexthdr != IPPROTO_UDP)
	502	return 0;
	503
	504	break;
	505	default:
	506	return 0;
	507	}
	508
	509	if (!pskb_may_pull(skb, header_len + sizeof(struct udphdr)))
510	return 0;
511	udphdr = (struct udphdr *)(skb->data + header_len);
512	header_len += sizeof(struct udphdr);
513
514	/* check for bootp port */
515	if ((ntohs(ethhdr->h_proto) == ETH_P_IP) &&
516	(ntohs(udphdr->dest) != 67))
517	return 0;
518
519	if ((ntohs(ethhdr->h_proto) == ETH_P_IPV6) &&
520	(ntohs(udphdr->dest) != 547))
521	return 0;
522
523	if (atomic_read(&bat_priv->gw_mode) == GW_MODE_SERVER)
524	return -1;
525
5d02b3cd LL	526	rcu_read_lock();
	527	if (!rcu_dereference(bat_priv->curr_gw)) {
	528	rcu_read_unlock();
c6c8fea2	529	return 0;
5d02b3cd LL	530	}
5d02b3cd LL	531	rcu_read_unlock();
c6c8fea2 SE	532
	533	return 1;
	534	}