[mirror_ubuntu-focal-kernel.git] / net / bridge / br_fdb.c

/*
 *	Forwarding database
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/rculist.h>
#include <linux/spinlock.h>
#include <linux/times.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/atomic.h>
#include <asm/unaligned.h>
#include "br_private.h"

static struct kmem_cache *br_fdb_cache __read_mostly;
static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		      const unsigned char *addr);
static void fdb_notify(const struct net_bridge_fdb_entry *, int);

static u32 fdb_salt __read_mostly;

int __init br_fdb_init(void)
{
	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
					 sizeof(struct net_bridge_fdb_entry),
					 0,
					 SLAB_HWCACHE_ALIGN, NULL);
	if (!br_fdb_cache)
		return -ENOMEM;

	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
	return 0;
}

void br_fdb_fini(void)
{
	kmem_cache_destroy(br_fdb_cache);
}


/* if topology_changing then use forward_delay (default 15 sec)
 * otherwise keep longer (default 5 minutes)
 */
static inline unsigned long hold_time(const struct net_bridge *br)
{
	return br->topology_change ? br->forward_delay : br->ageing_time;
}

static inline int has_expired(const struct net_bridge *br,
				  const struct net_bridge_fdb_entry *fdb)
{
	return !fdb->is_static &&
		time_before_eq(fdb->updated + hold_time(br), jiffies);
}

static inline int br_mac_hash(const unsigned char *mac)
{
	/* use 1 byte of OUI cnd 3 bytes of NIC */
	u32 key = get_unaligned((u32 *)(mac + 2));
	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
}

static void fdb_rcu_free(struct rcu_head *head)
{
	struct net_bridge_fdb_entry *ent
		= container_of(head, struct net_bridge_fdb_entry, rcu);
	kmem_cache_free(br_fdb_cache, ent);
}

static inline void fdb_delete(struct net_bridge_fdb_entry *f)
{
	fdb_notify(f, RTM_DELNEIGH);
	hlist_del_rcu(&f->hlist);
	call_rcu(&f->rcu, fdb_rcu_free);
}

void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
{
	struct net_bridge *br = p->br;
	int i;

	spin_lock_bh(&br->hash_lock);

	/* Search all chains since old address/hash is unknown */
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct hlist_node *h;
		hlist_for_each(h, &br->hash[i]) {
			struct net_bridge_fdb_entry *f;

			f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
			if (f->dst == p && f->is_local) {
				/* maybe another port has same hw addr? */
				struct net_bridge_port *op;
				list_for_each_entry(op, &br->port_list, list) {
					if (op != p &&
					    !compare_ether_addr(op->dev->dev_addr,
								f->addr.addr)) {
						f->dst = op;
						goto insert;
					}
				}

				/* delete old one */
				fdb_delete(f);
				goto insert;
			}
		}
	}
 insert:
	/* insert new address,  may fail if invalid address or dup. */
	fdb_insert(br, p, newaddr);

	spin_unlock_bh(&br->hash_lock);
}

void br_fdb_cleanup(unsigned long _data)
{
	struct net_bridge *br = (struct net_bridge *)_data;
	unsigned long delay = hold_time(br);
	unsigned long next_timer = jiffies + br->ageing_time;
	int i;

	spin_lock_bh(&br->hash_lock);
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct net_bridge_fdb_entry *f;
		struct hlist_node *h, *n;

		hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
			unsigned long this_timer;
			if (f->is_static)
				continue;
			this_timer = f->updated + delay;
			if (time_before_eq(this_timer, jiffies))
				fdb_delete(f);
			else if (time_before(this_timer, next_timer))
				next_timer = this_timer;
		}
	}
	spin_unlock_bh(&br->hash_lock);

	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
}

/* Completely flush all dynamic entries in forwarding database.*/
void br_fdb_flush(struct net_bridge *br)
{
	int i;

	spin_lock_bh(&br->hash_lock);
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct net_bridge_fdb_entry *f;
		struct hlist_node *h, *n;
		hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
			if (!f->is_static)
				fdb_delete(f);
		}
	}
	spin_unlock_bh(&br->hash_lock);
}

/* Flush all entries referring to a specific port.
 * if do_all is set also flush static entries
 */
void br_fdb_delete_by_port(struct net_bridge *br,
			   const struct net_bridge_port *p,
			   int do_all)
{
	int i;

	spin_lock_bh(&br->hash_lock);
	for (i = 0; i < BR_HASH_SIZE; i++) {
		struct hlist_node *h, *g;

		hlist_for_each_safe(h, g, &br->hash[i]) {
			struct net_bridge_fdb_entry *f
				= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
			if (f->dst != p)
				continue;

			if (f->is_static && !do_all)
				continue;
			/*
			 * if multiple ports all have the same device address
			 * then when one port is deleted, assign
			 * the local entry to other port
			 */
			if (f->is_local) {
				struct net_bridge_port *op;
				list_for_each_entry(op, &br->port_list, list) {
					if (op != p &&
					    !compare_ether_addr(op->dev->dev_addr,
								f->addr.addr)) {
						f->dst = op;
						goto skip_delete;
					}
				}
			}

			fdb_delete(f);
		skip_delete: ;
		}
	}
	spin_unlock_bh(&br->hash_lock);
}

/* No locking or refcounting, assumes caller has rcu_read_lock */
struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
					  const unsigned char *addr)
{
	struct hlist_node *h;
	struct net_bridge_fdb_entry *fdb;

	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
		if (!compare_ether_addr(fdb->addr.addr, addr)) {
			if (unlikely(has_expired(br, fdb)))
				break;
			return fdb;
		}
	}

	return NULL;
}

#if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE)
/* Interface used by ATM LANE hook to test
 * if an addr is on some other bridge port */
int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
{
	struct net_bridge_fdb_entry *fdb;
	struct net_bridge_port *port;
	int ret;

	rcu_read_lock();
	port = br_port_get_rcu(dev);
	if (!port)
		ret = 0;
	else {
		fdb = __br_fdb_get(port->br, addr);
		ret = fdb && fdb->dst->dev != dev &&
			fdb->dst->state == BR_STATE_FORWARDING;
	}
	rcu_read_unlock();

	return ret;
}
#endif /* CONFIG_ATM_LANE */

/*
 * Fill buffer with forwarding table records in
 * the API format.
 */
int br_fdb_fillbuf(struct net_bridge *br, void *buf,
		   unsigned long maxnum, unsigned long skip)
{
	struct __fdb_entry *fe = buf;
	int i, num = 0;
	struct hlist_node *h;
	struct net_bridge_fdb_entry *f;

	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));

	rcu_read_lock();
	for (i = 0; i < BR_HASH_SIZE; i++) {
		hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
			if (num >= maxnum)
				goto out;

			if (has_expired(br, f))
				continue;

			if (skip) {
				--skip;
				continue;
			}

			/* convert from internal format to API */
			memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);

			/* due to ABI compat need to split into hi/lo */
			fe->port_no = f->dst->port_no;
			fe->port_hi = f->dst->port_no >> 8;

			fe->is_local = f->is_local;
			if (!f->is_static)
				fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->updated);
			++fe;
			++num;
		}
	}

 out:
	rcu_read_unlock();

	return num;
}

static struct net_bridge_fdb_entry *fdb_find(struct hlist_head *head,
					     const unsigned char *addr)
{
	struct hlist_node *h;
	struct net_bridge_fdb_entry *fdb;

	hlist_for_each_entry(fdb, h, head, hlist) {
		if (!compare_ether_addr(fdb->addr.addr, addr))
			return fdb;
	}
	return NULL;
}

static struct net_bridge_fdb_entry *fdb_find_rcu(struct hlist_head *head,
						 const unsigned char *addr)
{
	struct hlist_node *h;
	struct net_bridge_fdb_entry *fdb;

	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
		if (!compare_ether_addr(fdb->addr.addr, addr))
			return fdb;
	}
	return NULL;
}

static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head,
					       struct net_bridge_port *source,
					       const unsigned char *addr)
{
	struct net_bridge_fdb_entry *fdb;

	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	if (fdb) {
		memcpy(fdb->addr.addr, addr, ETH_ALEN);
		fdb->dst = source;
		fdb->is_local = 0;
		fdb->is_static = 0;
		fdb->updated = fdb->used = jiffies;
		hlist_add_head_rcu(&fdb->hlist, head);
	}
	return fdb;
}

static int fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		  const unsigned char *addr)
{
	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	struct net_bridge_fdb_entry *fdb;

	if (!is_valid_ether_addr(addr))
		return -EINVAL;

	fdb = fdb_find(head, addr);
	if (fdb) {
		/* it is okay to have multiple ports with same
		 * address, just use the first one.
		 */
		if (fdb->is_local)
			return 0;
		br_warn(br, "adding interface %s with same address "
		       "as a received packet\n",
		       source->dev->name);
		fdb_delete(fdb);
	}

	fdb = fdb_create(head, source, addr);
	if (!fdb)
		return -ENOMEM;

	fdb->is_local = fdb->is_static = 1;
	fdb_notify(fdb, RTM_NEWNEIGH);
	return 0;
}

/* Add entry for local address of interface */
int br_fdb_insert(struct net_bridge *br, struct net_bridge_port *source,
		  const unsigned char *addr)
{
	int ret;

	spin_lock_bh(&br->hash_lock);
	ret = fdb_insert(br, source, addr);
	spin_unlock_bh(&br->hash_lock);
	return ret;
}

void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
		   const unsigned char *addr)
{
	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	struct net_bridge_fdb_entry *fdb;

	/* some users want to always flood. */
	if (hold_time(br) == 0)
		return;

	/* ignore packets unless we are using this port */
	if (!(source->state == BR_STATE_LEARNING ||
	      source->state == BR_STATE_FORWARDING))
		return;

	fdb = fdb_find_rcu(head, addr);
	if (likely(fdb)) {
		/* attempt to update an entry for a local interface */
		if (unlikely(fdb->is_local)) {
			if (net_ratelimit())
				br_warn(br, "received packet on %s with "
					"own address as source address\n",
					source->dev->name);
		} else {
			/* fastpath: update of existing entry */
			fdb->dst = source;
			fdb->updated = jiffies;
		}
	} else {
		spin_lock(&br->hash_lock);
		if (likely(!fdb_find(head, addr))) {
			fdb = fdb_create(head, source, addr);
			if (fdb)
				fdb_notify(fdb, RTM_NEWNEIGH);
		}
		/* else  we lose race and someone else inserts
		 * it first, don't bother updating
		 */
		spin_unlock(&br->hash_lock);
	}
}

static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
{
	if (fdb->is_local)
		return NUD_PERMANENT;
	else if (fdb->is_static)
		return NUD_NOARP;
	else if (has_expired(fdb->dst->br, fdb))
		return NUD_STALE;
	else
		return NUD_REACHABLE;
}

static int fdb_fill_info(struct sk_buff *skb,
			 const struct net_bridge_fdb_entry *fdb,
			 u32 pid, u32 seq, int type, unsigned int flags)
{
	unsigned long now = jiffies;
	struct nda_cacheinfo ci;
	struct nlmsghdr *nlh;
	struct ndmsg *ndm;

	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
	if (nlh == NULL)
		return -EMSGSIZE;


	ndm = nlmsg_data(nlh);
	ndm->ndm_family	 = AF_BRIDGE;
	ndm->ndm_pad1    = 0;
	ndm->ndm_pad2    = 0;
	ndm->ndm_flags	 = 0;
	ndm->ndm_type	 = 0;
	ndm->ndm_ifindex = fdb->dst->dev->ifindex;
	ndm->ndm_state   = fdb_to_nud(fdb);

	NLA_PUT(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr);

	ci.ndm_used	 = jiffies_to_clock_t(now - fdb->used);
	ci.ndm_confirmed = 0;
	ci.ndm_updated	 = jiffies_to_clock_t(now - fdb->updated);
	ci.ndm_refcnt	 = 0;
	NLA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci);

	return nlmsg_end(skb, nlh);

nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -EMSGSIZE;
}

static inline size_t fdb_nlmsg_size(void)
{
	return NLMSG_ALIGN(sizeof(struct ndmsg))
		+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
		+ nla_total_size(sizeof(struct nda_cacheinfo));
}

static void fdb_notify(const struct net_bridge_fdb_entry *fdb, int type)
{
	struct net *net = dev_net(fdb->dst->dev);
	struct sk_buff *skb;
	int err = -ENOBUFS;

	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
	if (skb == NULL)
		goto errout;

	err = fdb_fill_info(skb, fdb, 0, 0, type, 0);
	if (err < 0) {
		/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
		WARN_ON(err == -EMSGSIZE);
		kfree_skb(skb);
		goto errout;
	}
	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
	return;
errout:
	if (err < 0)
		rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
}

/* Dump information about entries, in response to GETNEIGH */
int br_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
	struct net *net = sock_net(skb->sk);
	struct net_device *dev;
	int idx = 0;

	rcu_read_lock();
	for_each_netdev_rcu(net, dev) {
		struct net_bridge *br = netdev_priv(dev);
		int i;

		if (!(dev->priv_flags & IFF_EBRIDGE))
			continue;

		for (i = 0; i < BR_HASH_SIZE; i++) {
			struct hlist_node *h;
			struct net_bridge_fdb_entry *f;

			hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
				if (idx < cb->args[0])
					goto skip;

				if (fdb_fill_info(skb, f,
						  NETLINK_CB(cb->skb).pid,
						  cb->nlh->nlmsg_seq,
						  RTM_NEWNEIGH,
						  NLM_F_MULTI) < 0)
					break;
skip:
				++idx;
			}
		}
	}
	rcu_read_unlock();

	cb->args[0] = idx;

	return skb->len;
}

/* Update (create or replace) forwarding database entry */
static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
			 __u16 state, __u16 flags)
{
	struct net_bridge *br = source->br;
	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	struct net_bridge_fdb_entry *fdb;

	fdb = fdb_find(head, addr);
	if (fdb == NULL) {
		if (!(flags & NLM_F_CREATE))
			return -ENOENT;

		fdb = fdb_create(head, source, addr);
		if (!fdb)
			return -ENOMEM;
		fdb_notify(fdb, RTM_NEWNEIGH);
	} else {
		if (flags & NLM_F_EXCL)
			return -EEXIST;
	}

	if (fdb_to_nud(fdb) != state) {
		if (state & NUD_PERMANENT)
			fdb->is_local = fdb->is_static = 1;
		else if (state & NUD_NOARP) {
			fdb->is_local = 0;
			fdb->is_static = 1;
		} else
			fdb->is_local = fdb->is_static = 0;

		fdb->updated = fdb->used = jiffies;
		fdb_notify(fdb, RTM_NEWNEIGH);
	}

	return 0;
}

/* Add new permanent fdb entry with RTM_NEWNEIGH */
int br_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct net *net = sock_net(skb->sk);
	struct ndmsg *ndm;
	struct nlattr *tb[NDA_MAX+1];
	struct net_device *dev;
	struct net_bridge_port *p;
	const __u8 *addr;
	int err;

	ASSERT_RTNL();
	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
	if (err < 0)
		return err;

	ndm = nlmsg_data(nlh);
	if (ndm->ndm_ifindex == 0) {
		pr_info("bridge: RTM_NEWNEIGH with invalid ifindex\n");
		return -EINVAL;
	}

	dev = __dev_get_by_index(net, ndm->ndm_ifindex);
	if (dev == NULL) {
		pr_info("bridge: RTM_NEWNEIGH with unknown ifindex\n");
		return -ENODEV;
	}

	if (!tb[NDA_LLADDR] || nla_len(tb[NDA_LLADDR]) != ETH_ALEN) {
		pr_info("bridge: RTM_NEWNEIGH with invalid address\n");
		return -EINVAL;
	}

	addr = nla_data(tb[NDA_LLADDR]);
	if (!is_valid_ether_addr(addr)) {
		pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
		return -EINVAL;
	}

	if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
		pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
		return -EINVAL;
	}

	p = br_port_get_rtnl(dev);
	if (p == NULL) {
		pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
			dev->name);
		return -EINVAL;
	}

	if (ndm->ndm_flags & NTF_USE) {
		rcu_read_lock();
		br_fdb_update(p->br, p, addr);
		rcu_read_unlock();
	} else {
		spin_lock_bh(&p->br->hash_lock);
		err = fdb_add_entry(p, addr, ndm->ndm_state, nlh->nlmsg_flags);
		spin_unlock_bh(&p->br->hash_lock);
	}

	return err;
}

static int fdb_delete_by_addr(struct net_bridge_port *p, const u8 *addr)
{
	struct net_bridge *br = p->br;
	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	struct net_bridge_fdb_entry *fdb;

	fdb = fdb_find(head, addr);
	if (!fdb)
		return -ENOENT;

	fdb_delete(fdb);
	return 0;
}

/* Remove neighbor entry with RTM_DELNEIGH */
int br_fdb_delete(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
	struct net *net = sock_net(skb->sk);
	struct ndmsg *ndm;
	struct net_bridge_port *p;
	struct nlattr *llattr;
	const __u8 *addr;
	struct net_device *dev;
	int err;

	ASSERT_RTNL();
	if (nlmsg_len(nlh) < sizeof(*ndm))
		return -EINVAL;

	ndm = nlmsg_data(nlh);
	if (ndm->ndm_ifindex == 0) {
		pr_info("bridge: RTM_DELNEIGH with invalid ifindex\n");
		return -EINVAL;
	}

	dev = __dev_get_by_index(net, ndm->ndm_ifindex);
	if (dev == NULL) {
		pr_info("bridge: RTM_DELNEIGH with unknown ifindex\n");
		return -ENODEV;
	}

	llattr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_LLADDR);
	if (llattr == NULL || nla_len(llattr) != ETH_ALEN) {
		pr_info("bridge: RTM_DELNEIGH with invalid address\n");
		return -EINVAL;
	}

	addr = nla_data(llattr);

	p = br_port_get_rtnl(dev);
	if (p == NULL) {
		pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
			dev->name);
		return -EINVAL;
	}

	spin_lock_bh(&p->br->hash_lock);
	err = fdb_delete_by_addr(p, addr);
	spin_unlock_bh(&p->br->hash_lock);

	return err;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Forwarding database
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <buytenh@gnu.org>
	7	*
1da177e4 LT	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the License, or (at your option) any later version.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
82524746	16	#include <linux/rculist.h>
1da177e4 LT	17	#include <linux/spinlock.h>
	18	#include <linux/times.h>
	19	#include <linux/netdevice.h>
	20	#include <linux/etherdevice.h>
	21	#include <linux/jhash.h>
3f890923	22	#include <linux/random.h>
5a0e3ad6	23	#include <linux/slab.h>
60063497	24	#include <linux/atomic.h>
3f890923	25	#include <asm/unaligned.h>
1da177e4 LT	26	#include "br_private.h"
1da177e4 LT	27
e18b890b	28	static struct kmem_cache *br_fdb_cache __read_mostly;
1da177e4 LT	29	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
1da177e4 LT	30	const unsigned char *addr);
b078f0df	31	static void fdb_notify(const struct net_bridge_fdb_entry *, int);
1da177e4	32
3f890923 SH	33	static u32 fdb_salt __read_mostly;
3f890923 SH	34
87a596e0	35	int __init br_fdb_init(void)
1da177e4 LT	36	{
	37	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
	38	sizeof(struct net_bridge_fdb_entry),
	39	0,
20c2df83	40	SLAB_HWCACHE_ALIGN, NULL);
87a596e0 AM	41	if (!br_fdb_cache)
	42	return -ENOMEM;
	43
3f890923	44	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
87a596e0	45	return 0;
1da177e4 LT	46	}
1da177e4 LT	47
73afc906	48	void br_fdb_fini(void)
1da177e4 LT	49	{
	50	kmem_cache_destroy(br_fdb_cache);
	51	}
	52
	53
	54	/* if topology_changing then use forward_delay (default 15 sec)
	55	* otherwise keep longer (default 5 minutes)
	56	*/
3f890923	57	static inline unsigned long hold_time(const struct net_bridge *br)
1da177e4 LT	58	{
	59	return br->topology_change ? br->forward_delay : br->ageing_time;
	60	}
	61
3f890923	62	static inline int has_expired(const struct net_bridge *br,
1da177e4 LT	63	const struct net_bridge_fdb_entry *fdb)
1da177e4 LT	64	{
f64f9e71	65	return !fdb->is_static &&
7cd8861a	66	time_before_eq(fdb->updated + hold_time(br), jiffies);
1da177e4 LT	67	}
1da177e4 LT	68
3f890923	69	static inline int br_mac_hash(const unsigned char *mac)
1da177e4	70	{
3f890923 SH	71	/* use 1 byte of OUI cnd 3 bytes of NIC */
	72	u32 key = get_unaligned((u32 *)(mac + 2));
	73	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
1da177e4 LT	74	}
1da177e4 LT	75
da678292 MM	76	static void fdb_rcu_free(struct rcu_head *head)
	77	{
	78	struct net_bridge_fdb_entry *ent
	79	= container_of(head, struct net_bridge_fdb_entry, rcu);
	80	kmem_cache_free(br_fdb_cache, ent);
	81	}
	82
3f890923	83	static inline void fdb_delete(struct net_bridge_fdb_entry *f)
1da177e4	84	{
b078f0df	85	fdb_notify(f, RTM_DELNEIGH);
1da177e4	86	hlist_del_rcu(&f->hlist);
da678292	87	call_rcu(&f->rcu, fdb_rcu_free);
1da177e4 LT	88	}
	89
	90	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	91	{
	92	struct net_bridge *br = p->br;
	93	int i;
9d6f229f	94
1da177e4 LT	95	spin_lock_bh(&br->hash_lock);
	96
	97	/* Search all chains since old address/hash is unknown */
	98	for (i = 0; i < BR_HASH_SIZE; i++) {
	99	struct hlist_node *h;
	100	hlist_for_each(h, &br->hash[i]) {
	101	struct net_bridge_fdb_entry *f;
	102
	103	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	104	if (f->dst == p && f->is_local) {
	105	/* maybe another port has same hw addr? */
	106	struct net_bridge_port *op;
	107	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	108	if (op != p &&
6ede2463 SH	109	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	110	f->addr.addr)) {
1da177e4 LT	111	f->dst = op;
	112	goto insert;
	113	}
	114	}
	115
	116	/* delete old one */
	117	fdb_delete(f);
	118	goto insert;
	119	}
	120	}
	121	}
	122	insert:
	123	/* insert new address, may fail if invalid address or dup. */
	124	fdb_insert(br, p, newaddr);
	125
	126	spin_unlock_bh(&br->hash_lock);
	127	}
	128
	129	void br_fdb_cleanup(unsigned long _data)
	130	{
	131	struct net_bridge br = (struct net_bridge )_data;
	132	unsigned long delay = hold_time(br);
25442e06	133	unsigned long next_timer = jiffies + br->ageing_time;
1da177e4 LT	134	int i;
	135
	136	spin_lock_bh(&br->hash_lock);
	137	for (i = 0; i < BR_HASH_SIZE; i++) {
	138	struct net_bridge_fdb_entry *f;
	139	struct hlist_node h, n;
	140
	141	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
071f7722 BE	142	unsigned long this_timer;
	143	if (f->is_static)
	144	continue;
7cd8861a	145	this_timer = f->updated + delay;
071f7722	146	if (time_before_eq(this_timer, jiffies))
1da177e4	147	fdb_delete(f);
2bec008c	148	else if (time_before(this_timer, next_timer))
071f7722	149	next_timer = this_timer;
1da177e4 LT	150	}
	151	}
	152	spin_unlock_bh(&br->hash_lock);
	153
25442e06	154	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
1da177e4 LT	155	}
1da177e4 LT	156
9cf63747 SH	157	/* Completely flush all dynamic entries in forwarding database.*/
	158	void br_fdb_flush(struct net_bridge *br)
	159	{
	160	int i;
	161
	162	spin_lock_bh(&br->hash_lock);
	163	for (i = 0; i < BR_HASH_SIZE; i++) {
	164	struct net_bridge_fdb_entry *f;
	165	struct hlist_node h, n;
	166	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	167	if (!f->is_static)
	168	fdb_delete(f);
	169	}
	170	}
	171	spin_unlock_bh(&br->hash_lock);
	172	}
1a620698	173
25985edc	174	/* Flush all entries referring to a specific port.
9cf63747 SH	175	* if do_all is set also flush static entries
9cf63747 SH	176	*/
1a620698 SH	177	void br_fdb_delete_by_port(struct net_bridge *br,
	178	const struct net_bridge_port *p,
	179	int do_all)
1da177e4 LT	180	{
	181	int i;
	182
	183	spin_lock_bh(&br->hash_lock);
	184	for (i = 0; i < BR_HASH_SIZE; i++) {
	185	struct hlist_node h, g;
9d6f229f	186
1da177e4 LT	187	hlist_for_each_safe(h, g, &br->hash[i]) {
	188	struct net_bridge_fdb_entry *f
	189	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
9d6f229f	190	if (f->dst != p)
1da177e4 LT	191	continue;
1da177e4 LT	192
1a620698 SH	193	if (f->is_static && !do_all)
1a620698 SH	194	continue;
1da177e4 LT	195	/*
	196	* if multiple ports all have the same device address
	197	* then when one port is deleted, assign
	198	* the local entry to other port
	199	*/
	200	if (f->is_local) {
	201	struct net_bridge_port *op;
	202	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	203	if (op != p &&
6ede2463 SH	204	!compare_ether_addr(op->dev->dev_addr,
6ede2463 SH	205	f->addr.addr)) {
1da177e4 LT	206	f->dst = op;
	207	goto skip_delete;
	208	}
	209	}
	210	}
	211
	212	fdb_delete(f);
	213	skip_delete: ;
	214	}
	215	}
	216	spin_unlock_bh(&br->hash_lock);
	217	}
	218
eeaf61d8	219	/* No locking or refcounting, assumes caller has rcu_read_lock */
1da177e4 LT	220	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	221	const unsigned char *addr)
	222	{
	223	struct hlist_node *h;
	224	struct net_bridge_fdb_entry *fdb;
	225
	226	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
6ede2463	227	if (!compare_ether_addr(fdb->addr.addr, addr)) {
1da177e4 LT	228	if (unlikely(has_expired(br, fdb)))
	229	break;
	230	return fdb;
	231	}
	232	}
	233
	234	return NULL;
	235	}
	236
da678292 MM	237	#if defined(CONFIG_ATM_LANE) \|\| defined(CONFIG_ATM_LANE_MODULE)
	238	/* Interface used by ATM LANE hook to test
	239	* if an addr is on some other bridge port */
	240	int br_fdb_test_addr(struct net_device dev, unsigned char addr)
1da177e4 LT	241	{
1da177e4 LT	242	struct net_bridge_fdb_entry *fdb;
b5ed54e9	243	struct net_bridge_port *port;
da678292 MM	244	int ret;
da678292 MM	245
1da177e4	246	rcu_read_lock();
b5ed54e9	247	port = br_port_get_rcu(dev);
	248	if (!port)
	249	ret = 0;
	250	else {
	251	fdb = __br_fdb_get(port->br, addr);
	252	ret = fdb && fdb->dst->dev != dev &&
	253	fdb->dst->state == BR_STATE_FORWARDING;
	254	}
1da177e4	255	rcu_read_unlock();
1da177e4	256
da678292	257	return ret;
1da177e4	258	}
da678292	259	#endif /* CONFIG_ATM_LANE */
1da177e4 LT	260
1da177e4 LT	261	/*
9d6f229f	262	* Fill buffer with forwarding table records in
1da177e4 LT	263	* the API format.
	264	*/
	265	int br_fdb_fillbuf(struct net_bridge br, void buf,
	266	unsigned long maxnum, unsigned long skip)
	267	{
	268	struct __fdb_entry *fe = buf;
	269	int i, num = 0;
	270	struct hlist_node *h;
	271	struct net_bridge_fdb_entry *f;
	272
	273	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
	274
	275	rcu_read_lock();
	276	for (i = 0; i < BR_HASH_SIZE; i++) {
	277	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	278	if (num >= maxnum)
	279	goto out;
	280
9d6f229f	281	if (has_expired(br, f))
1da177e4 LT	282	continue;
	283
	284	if (skip) {
	285	--skip;
	286	continue;
	287	}
	288
	289	/* convert from internal format to API */
	290	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
ae4f8fca SH	291
ae4f8fca SH	292	/* due to ABI compat need to split into hi/lo */
1da177e4	293	fe->port_no = f->dst->port_no;
ae4f8fca SH	294	fe->port_hi = f->dst->port_no >> 8;
ae4f8fca SH	295
1da177e4 LT	296	fe->is_local = f->is_local;
1da177e4 LT	297	if (!f->is_static)
7cd8861a	298	fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->updated);
1da177e4 LT	299	++fe;
	300	++num;
	301	}
	302	}
	303
	304	out:
	305	rcu_read_unlock();
	306
	307	return num;
	308	}
	309
664de48b	310	static struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
	311	const unsigned char *addr)
	312	{
	313	struct hlist_node *h;
	314	struct net_bridge_fdb_entry *fdb;
	315
	316	hlist_for_each_entry(fdb, h, head, hlist) {
	317	if (!compare_ether_addr(fdb->addr.addr, addr))
	318	return fdb;
	319	}
	320	return NULL;
	321	}
	322
	323	static struct net_bridge_fdb_entry fdb_find_rcu(struct hlist_head head,
	324	const unsigned char *addr)
1da177e4 LT	325	{
	326	struct hlist_node *h;
	327	struct net_bridge_fdb_entry *fdb;
	328
	329	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
6ede2463	330	if (!compare_ether_addr(fdb->addr.addr, addr))
1da177e4 LT	331	return fdb;
	332	}
	333	return NULL;
	334	}
	335
	336	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
	337	struct net_bridge_port *source,
03e9b64b	338	const unsigned char *addr)
1da177e4 LT	339	{
	340	struct net_bridge_fdb_entry *fdb;
	341
	342	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	343	if (fdb) {
	344	memcpy(fdb->addr.addr, addr, ETH_ALEN);
1da177e4	345	fdb->dst = source;
03e9b64b	346	fdb->is_local = 0;
03e9b64b	347	fdb->is_static = 0;
7cd8861a	348	fdb->updated = fdb->used = jiffies;
1158f762	349	hlist_add_head_rcu(&fdb->hlist, head);
1da177e4 LT	350	}
	351	return fdb;
	352	}
	353
	354	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	355	const unsigned char *addr)
	356	{
	357	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	358	struct net_bridge_fdb_entry *fdb;
	359
	360	if (!is_valid_ether_addr(addr))
	361	return -EINVAL;
	362
	363	fdb = fdb_find(head, addr);
	364	if (fdb) {
9d6f229f	365	/* it is okay to have multiple ports with same
1da177e4 LT	366	* address, just use the first one.
1da177e4 LT	367	*/
9d6f229f	368	if (fdb->is_local)
1da177e4	369	return 0;
28a16c97	370	br_warn(br, "adding interface %s with same address "
1da177e4 LT	371	"as a received packet\n",
	372	source->dev->name);
	373	fdb_delete(fdb);
9d6f229f	374	}
1da177e4	375
03e9b64b	376	fdb = fdb_create(head, source, addr);
03e9b64b	377	if (!fdb)
1da177e4 LT	378	return -ENOMEM;
1da177e4 LT	379
03e9b64b	380	fdb->is_local = fdb->is_static = 1;
f58ee4e1	381	fdb_notify(fdb, RTM_NEWNEIGH);
1da177e4 LT	382	return 0;
	383	}
	384
03e9b64b	385	/* Add entry for local address of interface */
1da177e4 LT	386	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
	387	const unsigned char *addr)
	388	{
	389	int ret;
	390
	391	spin_lock_bh(&br->hash_lock);
	392	ret = fdb_insert(br, source, addr);
	393	spin_unlock_bh(&br->hash_lock);
	394	return ret;
	395	}
	396
	397	void br_fdb_update(struct net_bridge br, struct net_bridge_port source,
	398	const unsigned char *addr)
	399	{
	400	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	401	struct net_bridge_fdb_entry *fdb;
	402
	403	/* some users want to always flood. */
	404	if (hold_time(br) == 0)
	405	return;
	406
df1c0b84 SH	407	/* ignore packets unless we are using this port */
	408	if (!(source->state == BR_STATE_LEARNING \|\|
	409	source->state == BR_STATE_FORWARDING))
	410	return;
	411
664de48b	412	fdb = fdb_find_rcu(head, addr);
1da177e4 LT	413	if (likely(fdb)) {
	414	/* attempt to update an entry for a local interface */
	415	if (unlikely(fdb->is_local)) {
9d6f229f	416	if (net_ratelimit())
28a16c97	417	br_warn(br, "received packet on %s with "
	418	"own address as source address\n",
	419	source->dev->name);
1da177e4 LT	420	} else {
	421	/* fastpath: update of existing entry */
	422	fdb->dst = source;
7cd8861a	423	fdb->updated = jiffies;
1da177e4 LT	424	}
1da177e4 LT	425	} else {
f8ae737d	426	spin_lock(&br->hash_lock);
f58ee4e1	427	if (likely(!fdb_find(head, addr))) {
	428	fdb = fdb_create(head, source, addr);
	429	if (fdb)
	430	fdb_notify(fdb, RTM_NEWNEIGH);
	431	}
1da177e4 LT	432	/* else we lose race and someone else inserts
	433	* it first, don't bother updating
	434	*/
f8ae737d	435	spin_unlock(&br->hash_lock);
1da177e4	436	}
1da177e4	437	}
b078f0df	438
	439	static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
	440	{
	441	if (fdb->is_local)
	442	return NUD_PERMANENT;
	443	else if (fdb->is_static)
	444	return NUD_NOARP;
	445	else if (has_expired(fdb->dst->br, fdb))
	446	return NUD_STALE;
	447	else
	448	return NUD_REACHABLE;
	449	}
	450
	451	static int fdb_fill_info(struct sk_buff *skb,
	452	const struct net_bridge_fdb_entry *fdb,
	453	u32 pid, u32 seq, int type, unsigned int flags)
	454	{
	455	unsigned long now = jiffies;
	456	struct nda_cacheinfo ci;
	457	struct nlmsghdr *nlh;
	458	struct ndmsg *ndm;
	459
	460	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*ndm), flags);
	461	if (nlh == NULL)
	462	return -EMSGSIZE;
	463
	464
	465	ndm = nlmsg_data(nlh);
	466	ndm->ndm_family = AF_BRIDGE;
	467	ndm->ndm_pad1 = 0;
	468	ndm->ndm_pad2 = 0;
	469	ndm->ndm_flags = 0;
	470	ndm->ndm_type = 0;
	471	ndm->ndm_ifindex = fdb->dst->dev->ifindex;
	472	ndm->ndm_state = fdb_to_nud(fdb);
	473
	474	NLA_PUT(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr);
	475
	476	ci.ndm_used = jiffies_to_clock_t(now - fdb->used);
	477	ci.ndm_confirmed = 0;
	478	ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated);
	479	ci.ndm_refcnt = 0;
	480	NLA_PUT(skb, NDA_CACHEINFO, sizeof(ci), &ci);
	481
	482	return nlmsg_end(skb, nlh);
	483
	484	nla_put_failure:
	485	nlmsg_cancel(skb, nlh);
	486	return -EMSGSIZE;
	487	}
	488
	489	static inline size_t fdb_nlmsg_size(void)
	490	{
	491	return NLMSG_ALIGN(sizeof(struct ndmsg))
	492	+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
	493	+ nla_total_size(sizeof(struct nda_cacheinfo));
	494	}
	495
	496	static void fdb_notify(const struct net_bridge_fdb_entry *fdb, int type)
	497	{
	498	struct net *net = dev_net(fdb->dst->dev);
	499	struct sk_buff *skb;
	500	int err = -ENOBUFS;
	501
502	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
503	if (skb == NULL)
504	goto errout;
505
506	err = fdb_fill_info(skb, fdb, 0, 0, type, 0);
507	if (err < 0) {
508	/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
509	WARN_ON(err == -EMSGSIZE);
510	kfree_skb(skb);
511	goto errout;
512	}
513	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
514	return;
515	errout:
516	if (err < 0)
517	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
518	}
519
520	/* Dump information about entries, in response to GETNEIGH */
521	int br_fdb_dump(struct sk_buff skb, struct netlink_callback cb)
522	{
523	struct net *net = sock_net(skb->sk);
524	struct net_device *dev;
525	int idx = 0;
526
527	rcu_read_lock();
528	for_each_netdev_rcu(net, dev) {
529	struct net_bridge *br = netdev_priv(dev);
530	int i;
531
532	if (!(dev->priv_flags & IFF_EBRIDGE))
533	continue;
534
535	for (i = 0; i < BR_HASH_SIZE; i++) {
536	struct hlist_node *h;
537	struct net_bridge_fdb_entry *f;
538
539	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
540	if (idx < cb->args[0])
541	goto skip;
542
543	if (fdb_fill_info(skb, f,
544	NETLINK_CB(cb->skb).pid,
545	cb->nlh->nlmsg_seq,
546	RTM_NEWNEIGH,
547	NLM_F_MULTI) < 0)
548	break;
549	skip:
550	++idx;
551	}
552	}
553	}
554	rcu_read_unlock();
555
556	cb->args[0] = idx;
557
558	return skb->len;
559	}
36fd2b63	560
292d1398	561	/* Update (create or replace) forwarding database entry */
36fd2b63	562	static int fdb_add_entry(struct net_bridge_port source, const __u8 addr,
64af1bac	563	__u16 state, __u16 flags)
36fd2b63	564	{
	565	struct net_bridge *br = source->br;
	566	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	567	struct net_bridge_fdb_entry *fdb;
	568
	569	fdb = fdb_find(head, addr);
64af1bac	570	if (fdb == NULL) {
	571	if (!(flags & NLM_F_CREATE))
	572	return -ENOENT;
36fd2b63	573
64af1bac	574	fdb = fdb_create(head, source, addr);
	575	if (!fdb)
	576	return -ENOMEM;
f58ee4e1	577	fdb_notify(fdb, RTM_NEWNEIGH);
64af1bac	578	} else {
	579	if (flags & NLM_F_EXCL)
	580	return -EEXIST;
292d1398	581	}
	582
	583	if (fdb_to_nud(fdb) != state) {
	584	if (state & NUD_PERMANENT)
	585	fdb->is_local = fdb->is_static = 1;
	586	else if (state & NUD_NOARP) {
	587	fdb->is_local = 0;
	588	fdb->is_static = 1;
	589	} else
	590	fdb->is_local = fdb->is_static = 0;
64af1bac	591
292d1398	592	fdb->updated = fdb->used = jiffies;
292d1398	593	fdb_notify(fdb, RTM_NEWNEIGH);
64af1bac	594	}
36fd2b63	595
36fd2b63	596	return 0;
	597	}
	598
	599	/* Add new permanent fdb entry with RTM_NEWNEIGH */
	600	int br_fdb_add(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	601	{
	602	struct net *net = sock_net(skb->sk);
	603	struct ndmsg *ndm;
	604	struct nlattr *tb[NDA_MAX+1];
	605	struct net_device *dev;
	606	struct net_bridge_port *p;
	607	const __u8 *addr;
	608	int err;
	609
	610	ASSERT_RTNL();
	611	err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
	612	if (err < 0)
	613	return err;
	614
	615	ndm = nlmsg_data(nlh);
	616	if (ndm->ndm_ifindex == 0) {
	617	pr_info("bridge: RTM_NEWNEIGH with invalid ifindex\n");
	618	return -EINVAL;
	619	}
	620
	621	dev = __dev_get_by_index(net, ndm->ndm_ifindex);
	622	if (dev == NULL) {
	623	pr_info("bridge: RTM_NEWNEIGH with unknown ifindex\n");
	624	return -ENODEV;
	625	}
	626
	627	if (!tb[NDA_LLADDR] \|\| nla_len(tb[NDA_LLADDR]) != ETH_ALEN) {
	628	pr_info("bridge: RTM_NEWNEIGH with invalid address\n");
	629	return -EINVAL;
	630	}
	631
	632	addr = nla_data(tb[NDA_LLADDR]);
	633	if (!is_valid_ether_addr(addr)) {
	634	pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
	635	return -EINVAL;
	636	}
	637
292d1398	638	if (!(ndm->ndm_state & (NUD_PERMANENT\|NUD_NOARP\|NUD_REACHABLE))) {
	639	pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
	640	return -EINVAL;
	641	}
	642
36fd2b63	643	p = br_port_get_rtnl(dev);
	644	if (p == NULL) {
	645	pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
	646	dev->name);
	647	return -EINVAL;
	648	}
	649
292d1398	650	if (ndm->ndm_flags & NTF_USE) {
	651	rcu_read_lock();
	652	br_fdb_update(p->br, p, addr);
	653	rcu_read_unlock();
	654	} else {
	655	spin_lock_bh(&p->br->hash_lock);
	656	err = fdb_add_entry(p, addr, ndm->ndm_state, nlh->nlmsg_flags);
	657	spin_unlock_bh(&p->br->hash_lock);
	658	}
36fd2b63	659
	660	return err;
	661	}
	662
	663	static int fdb_delete_by_addr(struct net_bridge_port p, const u8 addr)
	664	{
	665	struct net_bridge *br = p->br;
	666	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	667	struct net_bridge_fdb_entry *fdb;
	668
	669	fdb = fdb_find(head, addr);
	670	if (!fdb)
	671	return -ENOENT;
	672
	673	fdb_delete(fdb);
	674	return 0;
	675	}
	676
	677	/* Remove neighbor entry with RTM_DELNEIGH */
	678	int br_fdb_delete(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
	679	{
	680	struct net *net = sock_net(skb->sk);
	681	struct ndmsg *ndm;
	682	struct net_bridge_port *p;
	683	struct nlattr *llattr;
	684	const __u8 *addr;
	685	struct net_device *dev;
	686	int err;
	687
	688	ASSERT_RTNL();
	689	if (nlmsg_len(nlh) < sizeof(*ndm))
	690	return -EINVAL;
	691
	692	ndm = nlmsg_data(nlh);
	693	if (ndm->ndm_ifindex == 0) {
	694	pr_info("bridge: RTM_DELNEIGH with invalid ifindex\n");
	695	return -EINVAL;
	696	}
	697
	698	dev = __dev_get_by_index(net, ndm->ndm_ifindex);
	699	if (dev == NULL) {
	700	pr_info("bridge: RTM_DELNEIGH with unknown ifindex\n");
	701	return -ENODEV;
	702	}
	703
	704	llattr = nlmsg_find_attr(nlh, sizeof(*ndm), NDA_LLADDR);
	705	if (llattr == NULL \|\| nla_len(llattr) != ETH_ALEN) {
	706	pr_info("bridge: RTM_DELNEIGH with invalid address\n");
	707	return -EINVAL;
	708	}
	709
	710	addr = nla_data(llattr);
	711
	712	p = br_port_get_rtnl(dev);
	713	if (p == NULL) {
	714	pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
	715	dev->name);
	716	return -EINVAL;
	717	}
	718
	719	spin_lock_bh(&p->br->hash_lock);
	720	err = fdb_delete_by_addr(p, addr);
	721	spin_unlock_bh(&p->br->hash_lock);
	722
723	return err;
724	}