bridge_loop_avoidance.c 46.0 KB
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/* Copyright (C) 2011-2012 B.A.T.M.A.N. contributors:
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 *
 * Simon Wunderlich
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */

#include "main.h"
#include "hash.h"
#include "hard-interface.h"
#include "originator.h"
#include "bridge_loop_avoidance.h"
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#include "translation-table.h"
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#include "send.h"

#include <linux/etherdevice.h>
#include <linux/crc16.h>
#include <linux/if_arp.h>
#include <net/arp.h>
#include <linux/if_vlan.h>

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static const uint8_t batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
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static void batadv_bla_periodic_work(struct work_struct *work);
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static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
				     struct batadv_backbone_gw *backbone_gw);
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/* return the index of the claim */
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static inline uint32_t batadv_choose_claim(const void *data, uint32_t size)
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{
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	struct batadv_claim *claim = (struct batadv_claim *)data;
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	uint32_t hash = 0;

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	hash = batadv_hash_bytes(hash, &claim->addr, sizeof(claim->addr));
	hash = batadv_hash_bytes(hash, &claim->vid, sizeof(claim->vid));
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	hash += (hash << 3);
	hash ^= (hash >> 11);
	hash += (hash << 15);

	return hash % size;
}

/* return the index of the backbone gateway */
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static inline uint32_t batadv_choose_backbone_gw(const void *data,
						 uint32_t size)
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{
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	struct batadv_claim *claim = (struct batadv_claim *)data;
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	uint32_t hash = 0;

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	hash = batadv_hash_bytes(hash, &claim->addr, sizeof(claim->addr));
	hash = batadv_hash_bytes(hash, &claim->vid, sizeof(claim->vid));
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	hash += (hash << 3);
	hash ^= (hash >> 11);
	hash += (hash << 15);

	return hash % size;
}


/* compares address and vid of two backbone gws */
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static int batadv_compare_backbone_gw(const struct hlist_node *node,
				      const void *data2)
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{
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	const void *data1 = container_of(node, struct batadv_backbone_gw,
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					 hash_entry);

	return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0);
}

/* compares address and vid of two claims */
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static int batadv_compare_claim(const struct hlist_node *node,
				const void *data2)
87
{
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	const void *data1 = container_of(node, struct batadv_claim,
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					 hash_entry);

	return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0);
}

/* free a backbone gw */
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static void batadv_backbone_gw_free_ref(struct batadv_backbone_gw *backbone_gw)
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{
	if (atomic_dec_and_test(&backbone_gw->refcount))
		kfree_rcu(backbone_gw, rcu);
}

/* finally deinitialize the claim */
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static void batadv_claim_free_rcu(struct rcu_head *rcu)
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{
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	struct batadv_claim *claim;
105

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	claim = container_of(rcu, struct batadv_claim, rcu);
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	batadv_backbone_gw_free_ref(claim->backbone_gw);
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	kfree(claim);
}

/* free a claim, call claim_free_rcu if its the last reference */
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static void batadv_claim_free_ref(struct batadv_claim *claim)
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{
	if (atomic_dec_and_test(&claim->refcount))
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		call_rcu(&claim->rcu, batadv_claim_free_rcu);
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}

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/* @bat_priv: the bat priv with all the soft interface information
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 * @data: search data (may be local/static data)
 *
 * looks for a claim in the hash, and returns it if found
 * or NULL otherwise.
 */
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static struct batadv_claim *batadv_claim_hash_find(struct batadv_priv *bat_priv,
						   struct batadv_claim *data)
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{
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	struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
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	struct hlist_head *head;
	struct hlist_node *node;
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	struct batadv_claim *claim;
	struct batadv_claim *claim_tmp = NULL;
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	int index;

	if (!hash)
		return NULL;

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	index = batadv_choose_claim(data, hash->size);
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	head = &hash->table[index];

	rcu_read_lock();
	hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
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		if (!batadv_compare_claim(&claim->hash_entry, data))
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			continue;

		if (!atomic_inc_not_zero(&claim->refcount))
			continue;

		claim_tmp = claim;
		break;
	}
	rcu_read_unlock();

	return claim_tmp;
}

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/**
 * batadv_backbone_hash_find - looks for a claim in the hash
 * @bat_priv: the bat priv with all the soft interface information
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 * @addr: the address of the originator
 * @vid: the VLAN ID
 *
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 * Returns claim if found or NULL otherwise.
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 */
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static struct batadv_backbone_gw *
batadv_backbone_hash_find(struct batadv_priv *bat_priv,
			  uint8_t *addr, short vid)
168
{
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	struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
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	struct hlist_head *head;
	struct hlist_node *node;
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	struct batadv_backbone_gw search_entry, *backbone_gw;
	struct batadv_backbone_gw *backbone_gw_tmp = NULL;
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	int index;

	if (!hash)
		return NULL;

	memcpy(search_entry.orig, addr, ETH_ALEN);
	search_entry.vid = vid;

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	index = batadv_choose_backbone_gw(&search_entry, hash->size);
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	head = &hash->table[index];

	rcu_read_lock();
	hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
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		if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry,
						&search_entry))
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			continue;

		if (!atomic_inc_not_zero(&backbone_gw->refcount))
			continue;

		backbone_gw_tmp = backbone_gw;
		break;
	}
	rcu_read_unlock();

	return backbone_gw_tmp;
}

/* delete all claims for a backbone */
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static void
batadv_bla_del_backbone_claims(struct batadv_backbone_gw *backbone_gw)
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{
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	struct batadv_hashtable *hash;
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	struct hlist_node *node, *node_tmp;
	struct hlist_head *head;
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	struct batadv_claim *claim;
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	int i;
	spinlock_t *list_lock;	/* protects write access to the hash lists */

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	hash = backbone_gw->bat_priv->bla.claim_hash;
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	if (!hash)
		return;

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];
		list_lock = &hash->list_locks[i];

		spin_lock_bh(list_lock);
		hlist_for_each_entry_safe(claim, node, node_tmp,
					  head, hash_entry) {

			if (claim->backbone_gw != backbone_gw)
				continue;

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			batadv_claim_free_ref(claim);
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			hlist_del_rcu(node);
		}
		spin_unlock_bh(list_lock);
	}

	/* all claims gone, intialize CRC */
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	backbone_gw->crc = BATADV_BLA_CRC_INIT;
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}

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/**
 * batadv_bla_send_claim - sends a claim frame according to the provided info
 * @bat_priv: the bat priv with all the soft interface information
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 * @orig: the mac address to be announced within the claim
 * @vid: the VLAN ID
 * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
 */
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static void batadv_bla_send_claim(struct batadv_priv *bat_priv, uint8_t *mac,
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				  short vid, int claimtype)
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{
	struct sk_buff *skb;
	struct ethhdr *ethhdr;
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	struct batadv_hard_iface *primary_if;
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	struct net_device *soft_iface;
	uint8_t *hw_src;
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	struct batadv_bla_claim_dst local_claim_dest;
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	__be32 zeroip = 0;
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	primary_if = batadv_primary_if_get_selected(bat_priv);
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	if (!primary_if)
		return;

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	memcpy(&local_claim_dest, &bat_priv->bla.claim_dest,
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	       sizeof(local_claim_dest));
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	local_claim_dest.type = claimtype;

	soft_iface = primary_if->soft_iface;

	skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
			 /* IP DST: 0.0.0.0 */
			 zeroip,
			 primary_if->soft_iface,
			 /* IP SRC: 0.0.0.0 */
			 zeroip,
			 /* Ethernet DST: Broadcast */
			 NULL,
			 /* Ethernet SRC/HW SRC:  originator mac */
			 primary_if->net_dev->dev_addr,
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			 /* HW DST: FF:43:05:XX:YY:YY
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			  * with XX   = claim type
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			  * and YY:YY = group id
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			  */
			 (uint8_t *)&local_claim_dest);

	if (!skb)
		goto out;

	ethhdr = (struct ethhdr *)skb->data;
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	hw_src = (uint8_t *)ethhdr + ETH_HLEN + sizeof(struct arphdr);
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	/* now we pretend that the client would have sent this ... */
	switch (claimtype) {
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	case BATADV_CLAIM_TYPE_CLAIM:
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		/* normal claim frame
		 * set Ethernet SRC to the clients mac
		 */
		memcpy(ethhdr->h_source, mac, ETH_ALEN);
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		batadv_dbg(BATADV_DBG_BLA, bat_priv,
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			   "bla_send_claim(): CLAIM %pM on vid %d\n", mac, vid);
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		break;
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	case BATADV_CLAIM_TYPE_UNCLAIM:
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		/* unclaim frame
		 * set HW SRC to the clients mac
		 */
		memcpy(hw_src, mac, ETH_ALEN);
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		batadv_dbg(BATADV_DBG_BLA, bat_priv,
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			   "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac,
			   vid);
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		break;
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	case BATADV_CLAIM_TYPE_ANNOUNCE:
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		/* announcement frame
		 * set HW SRC to the special mac containg the crc
		 */
		memcpy(hw_src, mac, ETH_ALEN);
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		batadv_dbg(BATADV_DBG_BLA, bat_priv,
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			   "bla_send_claim(): ANNOUNCE of %pM on vid %d\n",
			   ethhdr->h_source, vid);
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		break;
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	case BATADV_CLAIM_TYPE_REQUEST:
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		/* request frame
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		 * set HW SRC and header destination to the receiving backbone
		 * gws mac
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		 */
		memcpy(hw_src, mac, ETH_ALEN);
		memcpy(ethhdr->h_dest, mac, ETH_ALEN);
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		batadv_dbg(BATADV_DBG_BLA, bat_priv,
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			   "bla_send_claim(): REQUEST of %pM to %pMon vid %d\n",
			   ethhdr->h_source, ethhdr->h_dest, vid);
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		break;

	}

	if (vid != -1)
		skb = vlan_insert_tag(skb, vid);

	skb_reset_mac_header(skb);
	skb->protocol = eth_type_trans(skb, soft_iface);
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	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
	batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
			   skb->len + ETH_HLEN);
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	soft_iface->last_rx = jiffies;

	netif_rx(skb);
out:
	if (primary_if)
343
		batadv_hardif_free_ref(primary_if);
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}

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/**
 * batadv_bla_get_backbone_gw
 * @bat_priv: the bat priv with all the soft interface information
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 * @orig: the mac address of the originator
 * @vid: the VLAN ID
 *
 * searches for the backbone gw or creates a new one if it could not
 * be found.
 */
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static struct batadv_backbone_gw *
batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig,
357
			   short vid, bool own_backbone)
358
{
359 360
	struct batadv_backbone_gw *entry;
	struct batadv_orig_node *orig_node;
361 362
	int hash_added;

363
	entry = batadv_backbone_hash_find(bat_priv, orig, vid);
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	if (entry)
		return entry;

368
	batadv_dbg(BATADV_DBG_BLA, bat_priv,
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		   "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
		   orig, vid);
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	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (!entry)
		return NULL;

	entry->vid = vid;
	entry->lasttime = jiffies;
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	entry->crc = BATADV_BLA_CRC_INIT;
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	entry->bat_priv = bat_priv;
	atomic_set(&entry->request_sent, 0);
	memcpy(entry->orig, orig, ETH_ALEN);

	/* one for the hash, one for returning */
	atomic_set(&entry->refcount, 2);

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	hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,
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				     batadv_compare_backbone_gw,
				     batadv_choose_backbone_gw, entry,
				     &entry->hash_entry);
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	if (unlikely(hash_added != 0)) {
		/* hash failed, free the structure */
		kfree(entry);
		return NULL;
	}

397
	/* this is a gateway now, remove any tt entries */
398
	orig_node = batadv_orig_hash_find(bat_priv, orig);
399
	if (orig_node) {
400 401
		batadv_tt_global_del_orig(bat_priv, orig_node,
					  "became a backbone gateway");
402
		batadv_orig_node_free_ref(orig_node);
403
	}
404

405
	if (own_backbone) {
406 407
		batadv_bla_send_announce(bat_priv, entry);

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		/* this will be decreased in the worker thread */
		atomic_inc(&entry->request_sent);
		atomic_inc(&bat_priv->bla.num_requests);
	}

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	return entry;
}

/* update or add the own backbone gw to make sure we announce
 * where we receive other backbone gws
 */
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static void
batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
				  struct batadv_hard_iface *primary_if,
				  short vid)
423
{
424
	struct batadv_backbone_gw *backbone_gw;
425

426 427
	backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
						 primary_if->net_dev->dev_addr,
428
						 vid, true);
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	if (unlikely(!backbone_gw))
		return;

	backbone_gw->lasttime = jiffies;
433
	batadv_backbone_gw_free_ref(backbone_gw);
434 435
}

436
/* @bat_priv: the bat priv with all the soft interface information
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 * @vid: the vid where the request came on
 *
 * Repeat all of our own claims, and finally send an ANNOUNCE frame
 * to allow the requester another check if the CRC is correct now.
 */
442 443 444
static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
				      struct batadv_hard_iface *primary_if,
				      short vid)
445 446 447
{
	struct hlist_node *node;
	struct hlist_head *head;
448
	struct batadv_hashtable *hash;
449 450
	struct batadv_claim *claim;
	struct batadv_backbone_gw *backbone_gw;
451 452
	int i;

453
	batadv_dbg(BATADV_DBG_BLA, bat_priv,
454
		   "bla_answer_request(): received a claim request, send all of our own claims again\n");
455

456 457 458
	backbone_gw = batadv_backbone_hash_find(bat_priv,
						primary_if->net_dev->dev_addr,
						vid);
459 460 461
	if (!backbone_gw)
		return;

462
	hash = bat_priv->bla.claim_hash;
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	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
			/* only own claims are interesting */
			if (claim->backbone_gw != backbone_gw)
				continue;

472
			batadv_bla_send_claim(bat_priv, claim->addr, claim->vid,
473
					      BATADV_CLAIM_TYPE_CLAIM);
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		}
		rcu_read_unlock();
	}

	/* finally, send an announcement frame */
479 480
	batadv_bla_send_announce(bat_priv, backbone_gw);
	batadv_backbone_gw_free_ref(backbone_gw);
481 482
}

483
/* @backbone_gw: the backbone gateway from whom we are out of sync
484 485 486 487 488
 *
 * When the crc is wrong, ask the backbone gateway for a full table update.
 * After the request, it will repeat all of his own claims and finally
 * send an announcement claim with which we can check again.
 */
489
static void batadv_bla_send_request(struct batadv_backbone_gw *backbone_gw)
490 491
{
	/* first, remove all old entries */
492
	batadv_bla_del_backbone_claims(backbone_gw);
493

494 495
	batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
		   "Sending REQUEST to %pM\n", backbone_gw->orig);
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	/* send request */
498
	batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
499
			      backbone_gw->vid, BATADV_CLAIM_TYPE_REQUEST);
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	/* no local broadcasts should be sent or received, for now. */
	if (!atomic_read(&backbone_gw->request_sent)) {
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		atomic_inc(&backbone_gw->bat_priv->bla.num_requests);
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		atomic_set(&backbone_gw->request_sent, 1);
	}
}

508
/* @bat_priv: the bat priv with all the soft interface information
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 * @backbone_gw: our backbone gateway which should be announced
 *
 * This function sends an announcement. It is called from multiple
 * places.
 */
514 515
static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
				     struct batadv_backbone_gw *backbone_gw)
516 517
{
	uint8_t mac[ETH_ALEN];
518
	__be16 crc;
519

520
	memcpy(mac, batadv_announce_mac, 4);
521
	crc = htons(backbone_gw->crc);
522
	memcpy(&mac[4], &crc, 2);
523

524
	batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid,
525
			      BATADV_CLAIM_TYPE_ANNOUNCE);
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}

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/**
 * batadv_bla_add_claim - Adds a claim in the claim hash
 * @bat_priv: the bat priv with all the soft interface information
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 * @mac: the mac address of the claim
 * @vid: the VLAN ID of the frame
 * @backbone_gw: the backbone gateway which claims it
 */
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static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
				 const uint8_t *mac, const short vid,
				 struct batadv_backbone_gw *backbone_gw)
539
{
540 541
	struct batadv_claim *claim;
	struct batadv_claim search_claim;
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	int hash_added;

	memcpy(search_claim.addr, mac, ETH_ALEN);
	search_claim.vid = vid;
546
	claim = batadv_claim_hash_find(bat_priv, &search_claim);
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	/* create a new claim entry if it does not exist yet. */
	if (!claim) {
		claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
		if (!claim)
			return;

		memcpy(claim->addr, mac, ETH_ALEN);
		claim->vid = vid;
		claim->lasttime = jiffies;
		claim->backbone_gw = backbone_gw;

		atomic_set(&claim->refcount, 2);
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		batadv_dbg(BATADV_DBG_BLA, bat_priv,
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			   "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n",
			   mac, vid);
563
		hash_added = batadv_hash_add(bat_priv->bla.claim_hash,
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					     batadv_compare_claim,
					     batadv_choose_claim, claim,
					     &claim->hash_entry);
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		if (unlikely(hash_added != 0)) {
			/* only local changes happened. */
			kfree(claim);
			return;
		}
	} else {
		claim->lasttime = jiffies;
		if (claim->backbone_gw == backbone_gw)
			/* no need to register a new backbone */
			goto claim_free_ref;

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		batadv_dbg(BATADV_DBG_BLA, bat_priv,
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			   "bla_add_claim(): changing ownership for %pM, vid %d\n",
			   mac, vid);
582

583
		claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
584
		batadv_backbone_gw_free_ref(claim->backbone_gw);
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	}
	/* set (new) backbone gw */
	atomic_inc(&backbone_gw->refcount);
	claim->backbone_gw = backbone_gw;

	backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
	backbone_gw->lasttime = jiffies;

claim_free_ref:
595
	batadv_claim_free_ref(claim);
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}

/* Delete a claim from the claim hash which has the
 * given mac address and vid.
 */
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static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
				 const uint8_t *mac, const short vid)
603
{
604
	struct batadv_claim search_claim, *claim;
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	memcpy(search_claim.addr, mac, ETH_ALEN);
	search_claim.vid = vid;
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	claim = batadv_claim_hash_find(bat_priv, &search_claim);
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	if (!claim)
		return;

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	batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n",
		   mac, vid);
614

615
	batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim,
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			   batadv_choose_claim, claim);
	batadv_claim_free_ref(claim); /* reference from the hash is gone */
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	claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);

	/* don't need the reference from hash_find() anymore */
622
	batadv_claim_free_ref(claim);
623 624 625
}

/* check for ANNOUNCE frame, return 1 if handled */
626
static int batadv_handle_announce(struct batadv_priv *bat_priv,
627 628
				  uint8_t *an_addr, uint8_t *backbone_addr,
				  short vid)
629
{
630
	struct batadv_backbone_gw *backbone_gw;
631 632
	uint16_t crc;

633
	if (memcmp(an_addr, batadv_announce_mac, 4) != 0)
634 635
		return 0;

636 637
	backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
						 false);
638 639 640 641 642 643 644

	if (unlikely(!backbone_gw))
		return 1;


	/* handle as ANNOUNCE frame */
	backbone_gw->lasttime = jiffies;
645
	crc = ntohs(*((__be16 *)(&an_addr[4])));
646

647
	batadv_dbg(BATADV_DBG_BLA, bat_priv,
648 649
		   "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %04x\n",
		   vid, backbone_gw->orig, crc);
650 651

	if (backbone_gw->crc != crc) {
652
		batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
653 654 655
			   "handle_announce(): CRC FAILED for %pM/%d (my = %04x, sent = %04x)\n",
			   backbone_gw->orig, backbone_gw->vid,
			   backbone_gw->crc, crc);
656

657
		batadv_bla_send_request(backbone_gw);
658 659 660 661 662
	} else {
		/* if we have sent a request and the crc was OK,
		 * we can allow traffic again.
		 */
		if (atomic_read(&backbone_gw->request_sent)) {
663
			atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
664 665 666 667
			atomic_set(&backbone_gw->request_sent, 0);
		}
	}

668
	batadv_backbone_gw_free_ref(backbone_gw);
669 670 671 672
	return 1;
}

/* check for REQUEST frame, return 1 if handled */
673 674
static int batadv_handle_request(struct batadv_priv *bat_priv,
				 struct batadv_hard_iface *primary_if,
675 676
				 uint8_t *backbone_addr,
				 struct ethhdr *ethhdr, short vid)
677 678
{
	/* check for REQUEST frame */
679
	if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest))
680 681 682 683 684
		return 0;

	/* sanity check, this should not happen on a normal switch,
	 * we ignore it in this case.
	 */
685
	if (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
686 687
		return 1;

688
	batadv_dbg(BATADV_DBG_BLA, bat_priv,
689 690
		   "handle_request(): REQUEST vid %d (sent by %pM)...\n",
		   vid, ethhdr->h_source);
691

692
	batadv_bla_answer_request(bat_priv, primary_if, vid);
693 694 695 696
	return 1;
}

/* check for UNCLAIM frame, return 1 if handled */
697 698
static int batadv_handle_unclaim(struct batadv_priv *bat_priv,
				 struct batadv_hard_iface *primary_if,
699 700
				 uint8_t *backbone_addr,
				 uint8_t *claim_addr, short vid)
701
{
702
	struct batadv_backbone_gw *backbone_gw;
703 704

	/* unclaim in any case if it is our own */
705 706
	if (primary_if && batadv_compare_eth(backbone_addr,
					     primary_if->net_dev->dev_addr))
707
		batadv_bla_send_claim(bat_priv, claim_addr, vid,
708
				      BATADV_CLAIM_TYPE_UNCLAIM);
709

710
	backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
711 712 713 714 715

	if (!backbone_gw)
		return 1;

	/* this must be an UNCLAIM frame */
716
	batadv_dbg(BATADV_DBG_BLA, bat_priv,
717 718
		   "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n",
		   claim_addr, vid, backbone_gw->orig);
719

720 721
	batadv_bla_del_claim(bat_priv, claim_addr, vid);
	batadv_backbone_gw_free_ref(backbone_gw);
722 723 724 725
	return 1;
}

/* check for CLAIM frame, return 1 if handled */
726 727
static int batadv_handle_claim(struct batadv_priv *bat_priv,
			       struct batadv_hard_iface *primary_if,
728 729
			       uint8_t *backbone_addr, uint8_t *claim_addr,
			       short vid)
730
{
731
	struct batadv_backbone_gw *backbone_gw;
732 733 734

	/* register the gateway if not yet available, and add the claim. */

735 736
	backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid,
						 false);
737 738 739 740 741

	if (unlikely(!backbone_gw))
		return 1;

	/* this must be a CLAIM frame */
742
	batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
743
	if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
744
		batadv_bla_send_claim(bat_priv, claim_addr, vid,
745
				      BATADV_CLAIM_TYPE_CLAIM);
746 747 748

	/* TODO: we could call something like tt_local_del() here. */

749
	batadv_backbone_gw_free_ref(backbone_gw);
750 751 752
	return 1;
}

753 754 755
/**
 * batadv_check_claim_group
 * @bat_priv: the bat priv with all the soft interface information
756 757 758 759 760 761 762 763 764 765 766 767 768
 * @hw_src: the Hardware source in the ARP Header
 * @hw_dst: the Hardware destination in the ARP Header
 * @ethhdr: pointer to the Ethernet header of the claim frame
 *
 * checks if it is a claim packet and if its on the same group.
 * This function also applies the group ID of the sender
 * if it is in the same mesh.
 *
 * returns:
 *	2  - if it is a claim packet and on the same group
 *	1  - if is a claim packet from another group
 *	0  - if it is not a claim packet
 */
769 770
static int batadv_check_claim_group(struct batadv_priv *bat_priv,
				    struct batadv_hard_iface *primary_if,
771 772
				    uint8_t *hw_src, uint8_t *hw_dst,
				    struct ethhdr *ethhdr)
773 774
{
	uint8_t *backbone_addr;
775
	struct batadv_orig_node *orig_node;
776
	struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
777

778
	bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
779
	bla_dst_own = &bat_priv->bla.claim_dest;
780 781 782 783 784 785 786 787 788 789

	/* check if it is a claim packet in general */
	if (memcmp(bla_dst->magic, bla_dst_own->magic,
		   sizeof(bla_dst->magic)) != 0)
		return 0;

	/* if announcement packet, use the source,
	 * otherwise assume it is in the hw_src
	 */
	switch (bla_dst->type) {
790
	case BATADV_CLAIM_TYPE_CLAIM:
791 792
		backbone_addr = hw_src;
		break;
793 794
	case BATADV_CLAIM_TYPE_REQUEST:
	case BATADV_CLAIM_TYPE_ANNOUNCE:
795
	case BATADV_CLAIM_TYPE_UNCLAIM:
796 797 798 799 800 801 802
		backbone_addr = ethhdr->h_source;
		break;
	default:
		return 0;
	}

	/* don't accept claim frames from ourselves */
803
	if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
804 805 806 807 808 809 810
		return 0;

	/* if its already the same group, it is fine. */
	if (bla_dst->group == bla_dst_own->group)
		return 2;

	/* lets see if this originator is in our mesh */
811
	orig_node = batadv_orig_hash_find(bat_priv, backbone_addr);
812 813 814 815 816 817 818 819 820

	/* dont accept claims from gateways which are not in
	 * the same mesh or group.
	 */
	if (!orig_node)
		return 1;

	/* if our mesh friends mac is bigger, use it for ourselves. */
	if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
821
		batadv_dbg(BATADV_DBG_BLA, bat_priv,
822 823
			   "taking other backbones claim group: %04x\n",
			   ntohs(bla_dst->group));
824 825 826
		bla_dst_own->group = bla_dst->group;
	}

827
	batadv_orig_node_free_ref(orig_node);
828 829 830 831 832

	return 2;
}


833
/* @bat_priv: the bat priv with all the soft interface information
834 835 836 837 838 839 840
 * @skb: the frame to be checked
 *
 * Check if this is a claim frame, and process it accordingly.
 *
 * returns 1 if it was a claim frame, otherwise return 0 to
 * tell the callee that it can use the frame on its own.
 */
841 842
static int batadv_bla_process_claim(struct batadv_priv *bat_priv,
				    struct batadv_hard_iface *primary_if,
843
				    struct sk_buff *skb)
844 845 846 847 848
{
	struct ethhdr *ethhdr;
	struct vlan_ethhdr *vhdr;
	struct arphdr *arphdr;
	uint8_t *hw_src, *hw_dst;
849
	struct batadv_bla_claim_dst *bla_dst;
850 851 852
	uint16_t proto;
	int headlen;
	short vid = -1;
853
	int ret;
854 855 856 857 858 859 860 861 862 863

	ethhdr = (struct ethhdr *)skb_mac_header(skb);

	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
		vhdr = (struct vlan_ethhdr *)ethhdr;
		vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
		proto = ntohs(vhdr->h_vlan_encapsulated_proto);
		headlen = sizeof(*vhdr);
	} else {
		proto = ntohs(ethhdr->h_proto);
864
		headlen = ETH_HLEN;
865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892
	}

	if (proto != ETH_P_ARP)
		return 0; /* not a claim frame */

	/* this must be a ARP frame. check if it is a claim. */

	if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
		return 0;

	/* pskb_may_pull() may have modified the pointers, get ethhdr again */
	ethhdr = (struct ethhdr *)skb_mac_header(skb);
	arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen);

	/* Check whether the ARP frame carries a valid
	 * IP information
	 */
	if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
		return 0;
	if (arphdr->ar_pro != htons(ETH_P_IP))
		return 0;
	if (arphdr->ar_hln != ETH_ALEN)
		return 0;
	if (arphdr->ar_pln != 4)
		return 0;

	hw_src = (uint8_t *)arphdr + sizeof(struct arphdr);
	hw_dst = hw_src + ETH_ALEN + 4;
893
	bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
894 895

	/* check if it is a claim frame. */
896 897
	ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
				       ethhdr);
898
	if (ret == 1)
899
		batadv_dbg(BATADV_DBG_BLA, bat_priv,
900 901
			   "bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
			   ethhdr->h_source, vid, hw_src, hw_dst);
902 903 904

	if (ret < 2)
		return ret;
905 906

	/* become a backbone gw ourselves on this vlan if not happened yet */
907
	batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
908 909 910

	/* check for the different types of claim frames ... */
	switch (bla_dst->type) {
911
	case BATADV_CLAIM_TYPE_CLAIM:
912 913
		if (batadv_handle_claim(bat_priv, primary_if, hw_src,
					ethhdr->h_source, vid))
914 915
			return 1;
		break;
916
	case BATADV_CLAIM_TYPE_UNCLAIM:
917 918
		if (batadv_handle_unclaim(bat_priv, primary_if,
					  ethhdr->h_source, hw_src, vid))
919 920 921
			return 1;
		break;

922
	case BATADV_CLAIM_TYPE_ANNOUNCE:
923 924
		if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source,
					   vid))
925 926
			return 1;
		break;
927
	case BATADV_CLAIM_TYPE_REQUEST:
928 929
		if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr,
					  vid))
930 931 932 933
			return 1;
		break;
	}

934
	batadv_dbg(BATADV_DBG_BLA, bat_priv,
935 936
		   "bla_process_claim(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
		   ethhdr->h_source, vid, hw_src, hw_dst);
937 938 939 940 941 942
	return 1;
}

/* Check when we last heard from other nodes, and remove them in case of
 * a time out, or clean all backbone gws if now is set.
 */
943
static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
944
{
945
	struct batadv_backbone_gw *backbone_gw;
946 947
	struct hlist_node *node, *node_tmp;
	struct hlist_head *head;
948
	struct batadv_hashtable *hash;
949 950 951
	spinlock_t *list_lock;	/* protects write access to the hash lists */
	int i;

952
	hash = bat_priv->bla.backbone_hash;
953 954 955 956 957 958 959 960 961 962 963 964
	if (!hash)
		return;

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];
		list_lock = &hash->list_locks[i];

		spin_lock_bh(list_lock);
		hlist_for_each_entry_safe(backbone_gw, node, node_tmp,
					  head, hash_entry) {
			if (now)
				goto purge_now;
965
			if (!batadv_has_timed_out(backbone_gw->lasttime,
966
						  BATADV_BLA_BACKBONE_TIMEOUT))
967 968
				continue;

969
			batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
970 971
				   "bla_purge_backbone_gw(): backbone gw %pM timed out\n",
				   backbone_gw->orig);
972 973 974 975

purge_now:
			/* don't wait for the pending request anymore */
			if (atomic_read(&backbone_gw->request_sent))
976
				atomic_dec(&bat_priv->bla.num_requests);
977

978
			batadv_bla_del_backbone_claims(backbone_gw);
979 980

			hlist_del_rcu(node);
981
			batadv_backbone_gw_free_ref(backbone_gw);
982 983 984 985 986
		}
		spin_unlock_bh(list_lock);
	}
}

987 988 989
/**
 * batadv_bla_purge_claims
 * @bat_priv: the bat priv with all the soft interface information
990 991 992 993 994 995
 * @primary_if: the selected primary interface, may be NULL if now is set
 * @now: whether the whole hash shall be wiped now
 *
 * Check when we heard last time from our own claims, and remove them in case of
 * a time out, or clean all claims if now is set
 */
996 997 998
static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
				    struct batadv_hard_iface *primary_if,
				    int now)
999
{
1000
	struct batadv_claim *claim;
1001 1002
	struct hlist_node *node;
	struct hlist_head *head;
1003
	struct batadv_hashtable *hash;
1004 1005
	int i;

1006
	hash = bat_priv->bla.claim_hash;
1007 1008 1009 1010 1011 1012 1013 1014 1015 1016
	if (!hash)
		return;

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
			if (now)
				goto purge_now;
1017 1018
			if (!batadv_compare_eth(claim->backbone_gw->orig,
						primary_if->net_dev->dev_addr))
1019
				continue;
1020
			if (!batadv_has_timed_out(claim->lasttime,
1021
						  BATADV_BLA_CLAIM_TIMEOUT))
1022 1023
				continue;

1024
			batadv_dbg(BATADV_DBG_BLA, bat_priv,
1025 1026
				   "bla_purge_claims(): %pM, vid %d, time out\n",
				   claim->addr, claim->vid);
1027 1028

purge_now:
1029 1030 1031
			batadv_handle_unclaim(bat_priv, primary_if,
					      claim->backbone_gw->orig,
					      claim->addr, claim->vid);
1032 1033 1034 1035 1036
		}
		rcu_read_unlock();
	}
}

1037 1038 1039
/**
 * batadv_bla_update_orig_address
 * @bat_priv: the bat priv with all the soft interface information
1040 1041 1042 1043 1044
 * @primary_if: the new selected primary_if
 * @oldif: the old primary interface, may be NULL
 *
 * Update the backbone gateways when the own orig address changes.
 */
1045 1046 1047
void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
				    struct batadv_hard_iface *primary_if,
				    struct batadv_hard_iface *oldif)
1048
{
1049
	struct batadv_backbone_gw *backbone_gw;
1050 1051
	struct hlist_node *node;
	struct hlist_head *head;
1052
	struct batadv_hashtable *hash;
1053
	__be16 group;
1054 1055
	int i;

1056
	/* reset bridge loop avoidance group id */
1057 1058
	group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
	bat_priv->bla.claim_dest.group = group;
1059

1060
	if (!oldif) {
1061 1062
		batadv_bla_purge_claims(bat_priv, NULL, 1);
		batadv_bla_purge_backbone_gw(bat_priv, 1);
1063 1064 1065
		return;
	}

1066
	hash = bat_priv->bla.backbone_hash;
1067 1068 1069 1070 1071 1072 1073 1074 1075
	if (!hash)
		return;

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
			/* own orig still holds the old value. */
1076 1077
			if (!batadv_compare_eth(backbone_gw->orig,
						oldif->net_dev->dev_addr))
1078 1079 1080 1081 1082 1083 1084
				continue;

			memcpy(backbone_gw->orig,
			       primary_if->net_dev->dev_addr, ETH_ALEN);
			/* send an announce frame so others will ask for our
			 * claims and update their tables.
			 */
1085
			batadv_bla_send_announce(bat_priv, backbone_gw);
1086 1087 1088 1089 1090 1091 1092 1093
		}
		rcu_read_unlock();
	}
}



/* (re)start the timer */
1094
static void batadv_bla_start_timer(struct batadv_priv *bat_priv)
1095
{
1096 1097
	INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
	queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work,
1098
			   msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1099 1100 1101 1102 1103 1104
}

/* periodic work to do:
 *  * purge structures when they are too old
 *  * send announcements
 */
1105
static void batadv_bla_periodic_work(struct work_struct *work)
1106
{
1107
	struct delayed_work *delayed_work;
1108
	struct batadv_priv *bat_priv;
1109
	struct batadv_priv_bla *priv_bla;
1110 1111
	struct hlist_node *node;
	struct hlist_head *head;
1112
	struct batadv_backbone_gw *backbone_gw;
1113
	struct batadv_hashtable *hash;
1114
	struct batadv_hard_iface *primary_if;
1115 1116
	int i;

1117
	delayed_work = container_of(work, struct delayed_work, work);
1118 1119
	priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
	bat_priv = container_of(priv_bla, struct batadv_priv, bla);
1120
	primary_if = batadv_primary_if_get_selected(bat_priv);
1121 1122 1123
	if (!primary_if)
		goto out;

1124 1125
	batadv_bla_purge_claims(bat_priv, primary_if, 0);
	batadv_bla_purge_backbone_gw(bat_priv, 0);
1126 1127 1128 1129

	if (!atomic_read(&bat_priv->bridge_loop_avoidance))
		goto out;

1130
	hash = bat_priv->bla.backbone_hash;
1131 1132 1133 1134 1135 1136 1137 1138
	if (!hash)
		goto out;

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
1139 1140
			if (!batadv_compare_eth(backbone_gw->orig,
						primary_if->net_dev->dev_addr))
1141 1142 1143 1144
				continue;

			backbone_gw->lasttime = jiffies;

1145
			batadv_bla_send_announce(bat_priv, backbone_gw);
1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158

			/* request_sent is only set after creation to avoid
			 * problems when we are not yet known as backbone gw
			 * in the backbone.
			 *
			 * We can reset this now and allow traffic again.
			 */

			if (atomic_read(&backbone_gw->request_sent) == 0)
				continue;

			atomic_dec(&backbone_gw->bat_priv->bla.num_requests);
			atomic_set(&backbone_gw->request_sent, 0);
1159 1160 1161 1162 1163
		}
		rcu_read_unlock();
	}
out:
	if (primary_if)
1164
		batadv_hardif_free_ref(primary_if);
1165

1166
	batadv_bla_start_timer(bat_priv);
1167 1168
}

1169 1170 1171 1172 1173
/* The hash for claim and backbone hash receive the same key because they
 * are getting initialized by hash_new with the same key. Reinitializing
 * them with to different keys to allow nested locking without generating
 * lockdep warnings
 */
1174 1175
static struct lock_class_key batadv_claim_hash_lock_class_key;
static struct lock_class_key batadv_backbone_hash_lock_class_key;
1176

1177
/* initialize all bla structures */
1178
int batadv_bla_init(struct batadv_priv *bat_priv)
1179
{
1180
	int i;
1181
	uint8_t claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
1182
	struct batadv_hard_iface *primary_if;
1183 1184
	uint16_t crc;
	unsigned long entrytime;
1185

1186 1187
	spin_lock_init(&bat_priv->bla.bcast_duplist_lock);

1188
	batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
1189

1190
	/* setting claim destination address */
1191 1192
	memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
	bat_priv->bla.claim_dest.type = 0;
1193
	primary_if = batadv_primary_if_get_selected(bat_priv);
1194
	if (primary_if) {
1195 1196
		crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN);
		bat_priv->bla.claim_dest.group = htons(crc);
1197
		batadv_hardif_free_ref(primary_if);
1198
	} else {
1199
		bat_priv->bla.claim_dest.group = 0; /* will be set later */
1200 1201
	}

1202
	/* initialize the duplicate list */
1203
	entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
1204
	for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
1205 1206
		bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
	bat_priv->bla.bcast_duplist_curr = 0;
1207

1208
	if (bat_priv->bla.claim_hash)
1209
		return 0;
1210

1211 1212
	bat_priv->bla.claim_hash = batadv_hash_new(128);
	bat_priv->bla.backbone_hash = batadv_hash_new(32);
1213

1214
	if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash)
1215
		return -ENOMEM;
1216

1217
	batadv_hash_set_lock_class(bat_priv->bla.claim_hash,
1218
				   &batadv_claim_hash_lock_class_key);
1219
	batadv_hash_set_lock_class(bat_priv->bla.backbone_hash,
1220
				   &batadv_backbone_hash_lock_class_key);
1221

1222
	batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
1223

1224
	batadv_bla_start_timer(bat_priv);
1225
	return 0;
1226 1227
}

1228 1229 1230
/**
 * batadv_bla_check_bcast_duplist
 * @bat_priv: the bat priv with all the soft interface information
1231 1232
 * @bcast_packet: encapsulated broadcast frame plus batman header
 * @bcast_packet_len: length of encapsulated broadcast frame plus batman header
1233 1234 1235 1236 1237 1238 1239 1240 1241
 *
 * check if it is on our broadcast list. Another gateway might
 * have sent the same packet because it is connected to the same backbone,
 * so we have to remove this duplicate.
 *
 * This is performed by checking the CRC, which will tell us
 * with a good chance that it is the same packet. If it is furthermore
 * sent by another host, drop it. We allow equal packets from
 * the same host however as this might be intended.
1242
 */
1243
int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
1244
				   struct batadv_bcast_packet *bcast_packet,
1245
				   int bcast_packet_len)
1246
{
1247
	int i, length, curr, ret = 0;
1248 1249
	uint8_t *content;
	uint16_t crc;
1250
	struct batadv_bcast_duplist_entry *entry;
1251

1252
	length = bcast_packet_len - sizeof(*bcast_packet);
1253 1254 1255 1256 1257 1258
	content = (uint8_t *)bcast_packet;
	content += sizeof(*bcast_packet);

	/* calculate the crc ... */
	crc = crc16(0, content, length);

1259 1260
	spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);

1261
	for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
1262 1263 1264
		curr = (bat_priv->bla.bcast_duplist_curr + i);
		curr %= BATADV_DUPLIST_SIZE;
		entry = &bat_priv->bla.bcast_duplist[curr];
1265 1266 1267 1268

		/* we can stop searching if the entry is too old ;
		 * later entries will be even older
		 */
1269 1270
		if (batadv_has_timed_out(entry->entrytime,
					 BATADV_DUPLIST_TIMEOUT))
1271 1272 1273 1274 1275
			break;

		if (entry->crc != crc)
			continue;

1276
		if (batadv_compare_eth(entry->orig, bcast_packet->orig))
1277 1278 1279 1280 1281
			continue;

		/* this entry seems to match: same crc, not too old,
		 * and from another gw. therefore return 1 to forbid it.
		 */
1282 1283
		ret = 1;
		goto out;
1284
	}
1285 1286 1287
	/* not found, add a new entry (overwrite the oldest entry)
	 * and allow it, its the first occurence.
	 */
1288
	curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
1289
	curr %= BATADV_DUPLIST_SIZE;
1290
	entry = &bat_priv->bla.bcast_duplist[curr];
1291 1292 1293
	entry->crc = crc;
	entry->entrytime = jiffies;
	memcpy(entry->orig, bcast_packet->orig, ETH_ALEN);
1294
	bat_priv->bla.bcast_duplist_curr = curr;
1295

1296 1297 1298 1299
out:
	spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);

	return ret;
1300 1301 1302 1303
}



1304
/* @bat_priv: the bat priv with all the soft interface information
1305 1306 1307 1308 1309 1310
 * @orig: originator mac address
 *
 * check if the originator is a gateway for any VLAN ID.
 *
 * returns 1 if it is found, 0 otherwise
 */
1311
int batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, uint8_t *orig)
1312
{
1313
	struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1314 1315
	struct hlist_head *head;
	struct hlist_node *node;
1316
	struct batadv_backbone_gw *backbone_gw;
1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329
	int i;

	if (!atomic_read(&bat_priv->bridge_loop_avoidance))
		return 0;

	if (!hash)
		return 0;

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
1330
			if (batadv_compare_eth(backbone_gw->orig, orig)) {
1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341
				rcu_read_unlock();
				return 1;
			}
		}
		rcu_read_unlock();
	}

	return 0;
}


1342 1343 1344
/**
 * batadv_bla_is_backbone_gw
 * @skb: the frame to be checked
1345 1346 1347 1348 1349 1350 1351
 * @orig_node: the orig_node of the frame
 * @hdr_size: maximum length of the frame
 *
 * bla_is_backbone_gw inspects the skb for the VLAN ID and returns 1
 * if the orig_node is also a gateway on the soft interface, otherwise it
 * returns 0.
 */
1352
int batadv_bla_is_backbone_gw(struct sk_buff *skb,
1353
			      struct batadv_orig_node *orig_node, int hdr_size)
1354 1355 1356
{
	struct ethhdr *ethhdr;
	struct vlan_ethhdr *vhdr;
1357
	struct batadv_backbone_gw *backbone_gw;
1358 1359 1360 1361 1362 1363
	short vid = -1;

	if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
		return 0;

	/* first, find out the vid. */
1364
	if (!pskb_may_pull(skb, hdr_size + ETH_HLEN))
1365 1366 1367 1368 1369 1370 1371 1372
		return 0;

	ethhdr = (struct ethhdr *)(((uint8_t *)skb->data) + hdr_size);

	if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
		if (!pskb_may_pull(skb, hdr_size + sizeof(struct vlan_ethhdr)))
			return 0;

1373
		vhdr = (struct vlan_ethhdr *)(skb->data + hdr_size);
1374 1375 1376 1377
		vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
	}

	/* see if this originator is a backbone gw for this VLAN */
1378 1379
	backbone_gw = batadv_backbone_hash_find(orig_node->bat_priv,
						orig_node->orig, vid);
1380 1381 1382
	if (!backbone_gw)
		return 0;

1383
	batadv_backbone_gw_free_ref(backbone_gw);
1384 1385 1386 1387
	return 1;
}

/* free all bla structures (for softinterface free or module unload) */
1388
void batadv_bla_free(struct batadv_priv *bat_priv)
1389
{
1390
	struct batadv_hard_iface *primary_if;
1391

1392
	cancel_delayed_work_sync(&bat_priv->bla.work);
1393
	primary_if = batadv_primary_if_get_selected(bat_priv);
1394

1395
	if (bat_priv->bla.claim_hash) {
1396
		batadv_bla_purge_claims(bat_priv, primary_if, 1);
1397 1398
		batadv_hash_destroy(bat_priv->bla.claim_hash);
		bat_priv->bla.claim_hash = NULL;
1399
	}
1400
	if (bat_priv->bla.backbone_hash) {
1401
		batadv_bla_purge_backbone_gw(bat_priv, 1);
1402 1403
		batadv_hash_destroy(bat_priv->bla.backbone_hash);
		bat_priv->bla.backbone_hash = NULL;
1404 1405
	}
	if (primary_if)
1406
		batadv_hardif_free_ref(primary_if);
1407 1408
}

1409 1410 1411
/**
 * batadv_bla_rx
 * @bat_priv: the bat priv with all the soft interface information
1412 1413
 * @skb: the frame to be checked
 * @vid: the VLAN ID of the frame
1414
 * @is_bcast: the packet came in a broadcast packet type.
1415 1416 1417 1418 1419 1420 1421 1422 1423
 *
 * bla_rx avoidance checks if:
 *  * we have to race for a claim
 *  * if the frame is allowed on the LAN
 *
 * in these cases, the skb is further handled by this function and
 * returns 1, otherwise it returns 0 and the caller shall further
 * process the skb.
 */
1424 1425
int batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid,
		  bool is_bcast)
1426 1427
{
	struct ethhdr *ethhdr;
1428 1429
	struct batadv_claim search_claim, *claim = NULL;
	struct batadv_hard_iface *primary_if;
1430 1431 1432 1433
	int ret;

	ethhdr = (struct ethhdr *)skb_mac_header(skb);

1434
	primary_if = batadv_primary_if_get_selected(bat_priv);
1435 1436 1437 1438 1439 1440 1441
	if (!primary_if)
		goto handled;

	if (!atomic_read(&bat_priv->bridge_loop_avoidance))
		goto allow;


1442
	if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1443
		/* don't allow broadcasts while requests are in flight */
1444
		if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
1445 1446 1447 1448
			goto handled;

	memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
	search_claim.vid = vid;
1449
	claim = batadv_claim_hash_find(bat_priv, &search_claim);
1450 1451 1452 1453 1454

	if (!claim) {
		/* possible optimization: race for a claim */
		/* No claim exists yet, claim it for us!
		 */
1455 1456 1457
		batadv_handle_claim(bat_priv, primary_if,
				    primary_if->net_dev->dev_addr,
				    ethhdr->h_source, vid);
1458 1459 1460 1461
		goto allow;
	}

	/* if it is our own claim ... */
1462 1463
	if (batadv_compare_eth(claim->backbone_gw->orig,
			       primary_if->net_dev->dev_addr)) {
1464 1465 1466 1467 1468 1469
		/* ... allow it in any case */
		claim->lasttime = jiffies;
		goto allow;
	}

	/* if it is a broadcast ... */
1470 1471 1472 1473 1474 1475 1476
	if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
		/* ... drop it. the responsible gateway is in charge.
		 *
		 * We need to check is_bcast because with the gateway
		 * feature, broadcasts (like DHCP requests) may be sent
		 * using a unicast packet type.
		 */
1477 1478 1479 1480 1481 1482
		goto handled;
	} else {
		/* seems the client considers us as its best gateway.
		 * send a claim and update the claim table
		 * immediately.
		 */
1483 1484 1485
		batadv_handle_claim(bat_priv, primary_if,
				    primary_if->net_dev->dev_addr,
				    ethhdr->h_source, vid);
1486 1487 1488
		goto allow;
	}
allow:
1489
	batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1490 1491 1492 1493 1494 1495 1496 1497 1498
	ret = 0;
	goto out;

handled:
	kfree_skb(skb);
	ret = 1;

out:
	if (primary_if)
1499
		batadv_hardif_free_ref(primary_if);
1500
	if (claim)
1501
		batadv_claim_free_ref(claim);
1502 1503 1504
	return ret;
}

1505 1506 1507
/**
 * batadv_bla_tx
 * @bat_priv: the bat priv with all the soft interface information
1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
 * @skb: the frame to be checked
 * @vid: the VLAN ID of the frame
 *
 * bla_tx checks if:
 *  * a claim was received which has to be processed
 *  * the frame is allowed on the mesh
 *
 * in these cases, the skb is further handled by this function and
 * returns 1, otherwise it returns 0 and the caller shall further
 * process the skb.
 */
1519
int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid)
1520 1521
{
	struct ethhdr *ethhdr;
1522 1523
	struct batadv_claim search_claim, *claim = NULL;
	struct batadv_hard_iface *primary_if;
1524 1525
	int ret = 0;

1526
	primary_if = batadv_primary_if_get_selected(bat_priv);
1527 1528 1529 1530 1531 1532 1533 1534 1535
	if (!primary_if)
		goto out;

	if (!atomic_read(&bat_priv->bridge_loop_avoidance))
		goto allow;

	/* in VLAN case, the mac header might not be set. */
	skb_reset_mac_header(skb);

1536
	if (batadv_bla_process_claim(bat_priv, primary_if, skb))
1537 1538 1539 1540
		goto handled;

	ethhdr = (struct ethhdr *)skb_mac_header(skb);

1541
	if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1542 1543 1544 1545 1546 1547 1548
		/* don't allow broadcasts while requests are in flight */
		if (is_multicast_ether_addr(ethhdr->h_dest))
			goto handled;

	memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
	search_claim.vid = vid;

1549
	claim = batadv_claim_hash_find(bat_priv, &search_claim);
1550 1551 1552 1553 1554 1555

	/* if no claim exists, allow it. */
	if (!claim)
		goto allow;

	/* check if we are responsible. */
1556 1557
	if (batadv_compare_eth(claim->backbone_gw->orig,
			       primary_if->net_dev->dev_addr)) {
1558 1559 1560
		/* if yes, the client has roamed and we have
		 * to unclaim it.
		 */
1561 1562 1563
		batadv_handle_unclaim(bat_priv, primary_if,
				      primary_if->net_dev->dev_addr,
				      ethhdr->h_source, vid);
1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579
		goto allow;
	}

	/* check if it is a multicast/broadcast frame */
	if (is_multicast_ether_addr(ethhdr->h_dest)) {
		/* drop it. the responsible gateway has forwarded it into
		 * the backbone network.
		 */
		goto handled;
	} else {
		/* we must allow it. at least if we are
		 * responsible for the DESTINATION.
		 */
		goto allow;
	}
allow:
1580
	batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1581 1582 1583 1584 1585 1586
	ret = 0;
	goto out;
handled:
	ret = 1;
out:
	if (primary_if)
1587
		batadv_hardif_free_ref(primary_if);
1588
	if (claim)
1589
		batadv_claim_free_ref(claim);
1590 1591
	return ret;
}
1592

1593
int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset)
1594 1595
{
	struct net_device *net_dev = (struct net_device *)seq->private;
1596
	struct batadv_priv *bat_priv = netdev_priv(net_dev);
1597
	struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
1598 1599
	struct batadv_claim *claim;
	struct batadv_hard_iface *primary_if;
1600 1601 1602 1603
	struct hlist_node *node;
	struct hlist_head *head;
	uint32_t i;
	bool is_own;
1604
	uint8_t *primary_addr;
1605

1606 1607
	primary_if = batadv_seq_print_text_primary_if_get(seq);
	if (!primary_if)
1608 1609
		goto out;

1610
	primary_addr = primary_if->net_dev->dev_addr;
1611 1612
	seq_printf(seq,
		   "Claims announced for the mesh %s (orig %pM, group id %04x)\n",
1613
		   net_dev->name, primary_addr,
1614
		   ntohs(bat_priv->bla.claim_dest.group));
1615 1616 1617 1618 1619 1620 1621
	seq_printf(seq, "   %-17s    %-5s    %-17s [o] (%-4s)\n",
		   "Client", "VID", "Originator", "CRC");
	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
1622 1623
			is_own = batadv_compare_eth(claim->backbone_gw->orig,
						    primary_addr);
1624 1625 1626 1627 1628 1629 1630 1631 1632 1633
			seq_printf(seq,	" * %pM on % 5d by %pM [%c] (%04x)\n",
				   claim->addr, claim->vid,
				   claim->backbone_gw->orig,
				   (is_own ? 'x' : ' '),
				   claim->backbone_gw->crc);
		}
		rcu_read_unlock();
	}
out:
	if (primary_if)
1634
		batadv_hardif_free_ref(primary_if);
1635
	return 0;
1636
}
1637 1638 1639 1640 1641

int batadv_bla_backbone_table_seq_print_text(struct seq_file *seq, void *offset)
{
	struct net_device *net_dev = (struct net_device *)seq->private;
	struct batadv_priv *bat_priv = netdev_priv(net_dev);
1642
	struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1643 1644 1645 1646 1647 1648 1649 1650 1651
	struct batadv_backbone_gw *backbone_gw;
	struct batadv_hard_iface *primary_if;
	struct hlist_node *node;
	struct hlist_head *head;
	int secs, msecs;
	uint32_t i;
	bool is_own;
	uint8_t *primary_addr;

1652 1653
	primary_if = batadv_seq_print_text_primary_if_get(seq);
	if (!primary_if)
1654 1655 1656 1657 1658 1659
		goto out;

	primary_addr = primary_if->net_dev->dev_addr;
	seq_printf(seq,
		   "Backbones announced for the mesh %s (orig %pM, group id %04x)\n",
		   net_dev->name, primary_addr,
1660
		   ntohs(bat_priv->bla.claim_dest.group));
1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687
	seq_printf(seq, "   %-17s    %-5s %-9s (%-4s)\n",
		   "Originator", "VID", "last seen", "CRC");
	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
			msecs = jiffies_to_msecs(jiffies -
						 backbone_gw->lasttime);
			secs = msecs / 1000;
			msecs = msecs % 1000;

			is_own = batadv_compare_eth(backbone_gw->orig,
						    primary_addr);
			if (is_own)
				continue;

			seq_printf(seq,
				   " * %pM on % 5d % 4i.%03is (%04x)\n",
				   backbone_gw->orig, backbone_gw->vid,
				   secs, msecs, backbone_gw->crc);
		}
		rcu_read_unlock();
	}
out:
	if (primary_if)
		batadv_hardif_free_ref(primary_if);
1688
	return 0;
1689
}