[GitHub/mt8127/android_kernel_alcatel_ttab.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(struct net_bridge *br,
		       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 void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
{
	hlist_del_rcu(&f->hlist);
	fdb_notify(br, f, RTM_DELNEIGH);
	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 &&
					    ether_addr_equal(op->dev->dev_addr,
							     f->addr.addr)) {
						f->dst = op;
						goto insert;
					}
				}

				/* delete old one */
				fdb_delete(br, 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_change_mac_address(struct net_bridge *br, const u8 *newaddr)
{
	struct net_bridge_fdb_entry *f;

	/* If old entry was unassociated with any port, then delete it. */
	f = __br_fdb_get(br, br->dev->dev_addr);
	if (f && f->is_local && !f->dst)
		fdb_delete(br, f);

	fdb_insert(br, NULL, newaddr);
}

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(&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(br, f);
			else if (time_before(this_timer, next_timer))
				next_timer = this_timer;
		}
	}
	spin_unlock(&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(br, 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 &&
					    ether_addr_equal(op->dev->dev_addr,
							     f->addr.addr)) {
						f->dst = op;
						goto skip_delete;
					}
				}
			}

			fdb_delete(br, 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 (ether_addr_equal(fdb->addr.addr, addr)) {
			if (unlikely(has_expired(br, fdb)))
				break;
			return fdb;
		}
	}

	return NULL;
}

#if IS_ENABLED(CONFIG_ATM_LANE)
/* 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 && 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;

			/* ignore pseudo entry for local MAC address */
			if (!f->dst)
				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_delta_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 (ether_addr_equal(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 (ether_addr_equal(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(br, fdb);
	}

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

	fdb->is_local = fdb->is_static = 1;
	fdb_notify(br, 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(br, 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 *br,
			 const struct net_bridge_fdb_entry *fdb,
			 u32 portid, 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, portid, 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 ? fdb->dst->dev->ifindex : br->dev->ifindex;
	ndm->ndm_state   = fdb_to_nud(fdb);

	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
		goto nla_put_failure;
	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;
	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
		goto nla_put_failure;
	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(struct net_bridge *br,
		       const struct net_bridge_fdb_entry *fdb, int type)
{
	struct net *net = dev_net(br->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, br, 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_device *dev,
		int idx)
{
	struct net_bridge *br = netdev_priv(dev);
	int i;

	if (!(dev->priv_flags & IFF_EBRIDGE))
		goto out;

	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, br, f,
					  NETLINK_CB(cb->skb).portid,
					  cb->nlh->nlmsg_seq,
					  RTM_NEWNEIGH,
					  NLM_F_MULTI) < 0)
				break;
skip:
			++idx;
		}
	}

out:
	return idx;
}

/* 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(br, 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(br, fdb, RTM_NEWNEIGH);
	}

	return 0;
}

/* Add new permanent fdb entry with RTM_NEWNEIGH */
int br_fdb_add(struct ndmsg *ndm, struct net_device *dev,
	       unsigned char *addr, u16 nlh_flags)
{
	struct net_bridge_port *p;
	int err = 0;

	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_flags);
		spin_unlock_bh(&p->br->hash_lock);
	}

	return err;
}

static int fdb_delete_by_addr(struct net_bridge_port *p, 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(p->br, fdb);
	return 0;
}

/* Remove neighbor entry with RTM_DELNEIGH */
int br_fdb_delete(struct ndmsg *ndm, struct net_device *dev,
		  unsigned char *addr)
{
	struct net_bridge_port *p;
	int err;

	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);
31e8a49c	31	static void fdb_notify(struct net_bridge *br,
31e8a49c	32	const struct net_bridge_fdb_entry *, int);
1da177e4	33
3f890923 SH	34	static u32 fdb_salt __read_mostly;
3f890923 SH	35
87a596e0	36	int __init br_fdb_init(void)
1da177e4 LT	37	{
	38	br_fdb_cache = kmem_cache_create("bridge_fdb_cache",
	39	sizeof(struct net_bridge_fdb_entry),
	40	0,
20c2df83	41	SLAB_HWCACHE_ALIGN, NULL);
87a596e0 AM	42	if (!br_fdb_cache)
	43	return -ENOMEM;
	44
3f890923	45	get_random_bytes(&fdb_salt, sizeof(fdb_salt));
87a596e0	46	return 0;
1da177e4 LT	47	}
1da177e4 LT	48
73afc906	49	void br_fdb_fini(void)
1da177e4 LT	50	{
	51	kmem_cache_destroy(br_fdb_cache);
	52	}
	53
	54
	55	/* if topology_changing then use forward_delay (default 15 sec)
	56	* otherwise keep longer (default 5 minutes)
	57	*/
3f890923	58	static inline unsigned long hold_time(const struct net_bridge *br)
1da177e4 LT	59	{
	60	return br->topology_change ? br->forward_delay : br->ageing_time;
	61	}
	62
3f890923	63	static inline int has_expired(const struct net_bridge *br,
1da177e4 LT	64	const struct net_bridge_fdb_entry *fdb)
1da177e4 LT	65	{
f64f9e71	66	return !fdb->is_static &&
7cd8861a	67	time_before_eq(fdb->updated + hold_time(br), jiffies);
1da177e4 LT	68	}
1da177e4 LT	69
3f890923	70	static inline int br_mac_hash(const unsigned char *mac)
1da177e4	71	{
3f890923 SH	72	/* use 1 byte of OUI cnd 3 bytes of NIC */
	73	u32 key = get_unaligned((u32 *)(mac + 2));
	74	return jhash_1word(key, fdb_salt) & (BR_HASH_SIZE - 1);
1da177e4 LT	75	}
1da177e4 LT	76
da678292 MM	77	static void fdb_rcu_free(struct rcu_head *head)
	78	{
	79	struct net_bridge_fdb_entry *ent
	80	= container_of(head, struct net_bridge_fdb_entry, rcu);
	81	kmem_cache_free(br_fdb_cache, ent);
	82	}
	83
31e8a49c	84	static void fdb_delete(struct net_bridge br, struct net_bridge_fdb_entry f)
1da177e4 LT	85	{
1da177e4 LT	86	hlist_del_rcu(&f->hlist);
31e8a49c	87	fdb_notify(br, f, RTM_DELNEIGH);
da678292	88	call_rcu(&f->rcu, fdb_rcu_free);
1da177e4 LT	89	}
	90
	91	void br_fdb_changeaddr(struct net_bridge_port p, const unsigned char newaddr)
	92	{
	93	struct net_bridge *br = p->br;
	94	int i;
9d6f229f	95
1da177e4 LT	96	spin_lock_bh(&br->hash_lock);
	97
	98	/* Search all chains since old address/hash is unknown */
	99	for (i = 0; i < BR_HASH_SIZE; i++) {
	100	struct hlist_node *h;
	101	hlist_for_each(h, &br->hash[i]) {
	102	struct net_bridge_fdb_entry *f;
	103
	104	f = hlist_entry(h, struct net_bridge_fdb_entry, hlist);
	105	if (f->dst == p && f->is_local) {
	106	/* maybe another port has same hw addr? */
	107	struct net_bridge_port *op;
	108	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	109	if (op != p &&
9a7b6ef9 JP	110	ether_addr_equal(op->dev->dev_addr,
9a7b6ef9 JP	111	f->addr.addr)) {
1da177e4 LT	112	f->dst = op;
	113	goto insert;
	114	}
	115	}
	116
	117	/* delete old one */
31e8a49c	118	fdb_delete(br, f);
1da177e4 LT	119	goto insert;
	120	}
	121	}
	122	}
	123	insert:
	124	/* insert new address, may fail if invalid address or dup. */
	125	fdb_insert(br, p, newaddr);
	126
	127	spin_unlock_bh(&br->hash_lock);
	128	}
	129
43598813	130	void br_fdb_change_mac_address(struct net_bridge br, const u8 newaddr)
	131	{
	132	struct net_bridge_fdb_entry *f;
	133
	134	/* If old entry was unassociated with any port, then delete it. */
	135	f = __br_fdb_get(br, br->dev->dev_addr);
	136	if (f && f->is_local && !f->dst)
	137	fdb_delete(br, f);
	138
	139	fdb_insert(br, NULL, newaddr);
	140	}
	141
1da177e4 LT	142	void br_fdb_cleanup(unsigned long _data)
	143	{
	144	struct net_bridge br = (struct net_bridge )_data;
	145	unsigned long delay = hold_time(br);
25442e06	146	unsigned long next_timer = jiffies + br->ageing_time;
1da177e4 LT	147	int i;
1da177e4 LT	148
27a42938	149	spin_lock(&br->hash_lock);
1da177e4 LT	150	for (i = 0; i < BR_HASH_SIZE; i++) {
	151	struct net_bridge_fdb_entry *f;
	152	struct hlist_node h, n;
	153
	154	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
071f7722 BE	155	unsigned long this_timer;
	156	if (f->is_static)
	157	continue;
7cd8861a	158	this_timer = f->updated + delay;
071f7722	159	if (time_before_eq(this_timer, jiffies))
31e8a49c	160	fdb_delete(br, f);
2bec008c	161	else if (time_before(this_timer, next_timer))
071f7722	162	next_timer = this_timer;
1da177e4 LT	163	}
1da177e4 LT	164	}
27a42938	165	spin_unlock(&br->hash_lock);
1da177e4	166
25442e06	167	mod_timer(&br->gc_timer, round_jiffies_up(next_timer));
1da177e4 LT	168	}
1da177e4 LT	169
9cf63747 SH	170	/* Completely flush all dynamic entries in forwarding database.*/
	171	void br_fdb_flush(struct net_bridge *br)
	172	{
	173	int i;
	174
	175	spin_lock_bh(&br->hash_lock);
	176	for (i = 0; i < BR_HASH_SIZE; i++) {
	177	struct net_bridge_fdb_entry *f;
	178	struct hlist_node h, n;
	179	hlist_for_each_entry_safe(f, h, n, &br->hash[i], hlist) {
	180	if (!f->is_static)
31e8a49c	181	fdb_delete(br, f);
9cf63747 SH	182	}
	183	}
	184	spin_unlock_bh(&br->hash_lock);
	185	}
1a620698	186
25985edc	187	/* Flush all entries referring to a specific port.
9cf63747 SH	188	* if do_all is set also flush static entries
9cf63747 SH	189	*/
1a620698 SH	190	void br_fdb_delete_by_port(struct net_bridge *br,
	191	const struct net_bridge_port *p,
	192	int do_all)
1da177e4 LT	193	{
	194	int i;
	195
	196	spin_lock_bh(&br->hash_lock);
	197	for (i = 0; i < BR_HASH_SIZE; i++) {
	198	struct hlist_node h, g;
9d6f229f	199
1da177e4 LT	200	hlist_for_each_safe(h, g, &br->hash[i]) {
	201	struct net_bridge_fdb_entry *f
	202	= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
9d6f229f	203	if (f->dst != p)
1da177e4 LT	204	continue;
1da177e4 LT	205
1a620698 SH	206	if (f->is_static && !do_all)
1a620698 SH	207	continue;
1da177e4 LT	208	/*
	209	* if multiple ports all have the same device address
	210	* then when one port is deleted, assign
	211	* the local entry to other port
	212	*/
	213	if (f->is_local) {
	214	struct net_bridge_port *op;
	215	list_for_each_entry(op, &br->port_list, list) {
9d6f229f	216	if (op != p &&
9a7b6ef9 JP	217	ether_addr_equal(op->dev->dev_addr,
9a7b6ef9 JP	218	f->addr.addr)) {
1da177e4 LT	219	f->dst = op;
	220	goto skip_delete;
	221	}
	222	}
	223	}
	224
31e8a49c	225	fdb_delete(br, f);
1da177e4 LT	226	skip_delete: ;
	227	}
	228	}
	229	spin_unlock_bh(&br->hash_lock);
	230	}
	231
eeaf61d8	232	/* No locking or refcounting, assumes caller has rcu_read_lock */
1da177e4 LT	233	struct net_bridge_fdb_entry __br_fdb_get(struct net_bridge br,
	234	const unsigned char *addr)
	235	{
	236	struct hlist_node *h;
	237	struct net_bridge_fdb_entry *fdb;
	238
	239	hlist_for_each_entry_rcu(fdb, h, &br->hash[br_mac_hash(addr)], hlist) {
9a7b6ef9	240	if (ether_addr_equal(fdb->addr.addr, addr)) {
1da177e4 LT	241	if (unlikely(has_expired(br, fdb)))
	242	break;
	243	return fdb;
	244	}
	245	}
	246
	247	return NULL;
	248	}
	249
e6373c4c	250	#if IS_ENABLED(CONFIG_ATM_LANE)
da678292 MM	251	/* Interface used by ATM LANE hook to test
	252	* if an addr is on some other bridge port */
	253	int br_fdb_test_addr(struct net_device dev, unsigned char addr)
1da177e4 LT	254	{
1da177e4 LT	255	struct net_bridge_fdb_entry *fdb;
b5ed54e9	256	struct net_bridge_port *port;
da678292 MM	257	int ret;
da678292 MM	258
1da177e4	259	rcu_read_lock();
b5ed54e9	260	port = br_port_get_rcu(dev);
	261	if (!port)
	262	ret = 0;
	263	else {
	264	fdb = __br_fdb_get(port->br, addr);
43598813	265	ret = fdb && fdb->dst && fdb->dst->dev != dev &&
b5ed54e9	266	fdb->dst->state == BR_STATE_FORWARDING;
b5ed54e9	267	}
1da177e4	268	rcu_read_unlock();
1da177e4	269
da678292	270	return ret;
1da177e4	271	}
da678292	272	#endif /* CONFIG_ATM_LANE */
1da177e4 LT	273
1da177e4 LT	274	/*
9d6f229f	275	* Fill buffer with forwarding table records in
1da177e4 LT	276	* the API format.
	277	*/
	278	int br_fdb_fillbuf(struct net_bridge br, void buf,
	279	unsigned long maxnum, unsigned long skip)
	280	{
	281	struct __fdb_entry *fe = buf;
	282	int i, num = 0;
	283	struct hlist_node *h;
	284	struct net_bridge_fdb_entry *f;
	285
	286	memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
	287
	288	rcu_read_lock();
	289	for (i = 0; i < BR_HASH_SIZE; i++) {
	290	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	291	if (num >= maxnum)
	292	goto out;
	293
9d6f229f	294	if (has_expired(br, f))
1da177e4 LT	295	continue;
1da177e4 LT	296
43598813	297	/* ignore pseudo entry for local MAC address */
	298	if (!f->dst)
	299	continue;
	300
1da177e4 LT	301	if (skip) {
	302	--skip;
	303	continue;
	304	}
	305
	306	/* convert from internal format to API */
	307	memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
ae4f8fca SH	308
ae4f8fca SH	309	/* due to ABI compat need to split into hi/lo */
1da177e4	310	fe->port_no = f->dst->port_no;
ae4f8fca SH	311	fe->port_hi = f->dst->port_no >> 8;
ae4f8fca SH	312
1da177e4 LT	313	fe->is_local = f->is_local;
1da177e4 LT	314	if (!f->is_static)
a399a805	315	fe->ageing_timer_value = jiffies_delta_to_clock_t(jiffies - f->updated);
1da177e4 LT	316	++fe;
	317	++num;
	318	}
	319	}
	320
	321	out:
	322	rcu_read_unlock();
	323
	324	return num;
	325	}
	326
664de48b	327	static struct net_bridge_fdb_entry fdb_find(struct hlist_head head,
	328	const unsigned char *addr)
	329	{
	330	struct hlist_node *h;
	331	struct net_bridge_fdb_entry *fdb;
	332
	333	hlist_for_each_entry(fdb, h, head, hlist) {
9a7b6ef9	334	if (ether_addr_equal(fdb->addr.addr, addr))
664de48b	335	return fdb;
	336	}
	337	return NULL;
	338	}
	339
	340	static struct net_bridge_fdb_entry fdb_find_rcu(struct hlist_head head,
	341	const unsigned char *addr)
1da177e4 LT	342	{
	343	struct hlist_node *h;
	344	struct net_bridge_fdb_entry *fdb;
	345
	346	hlist_for_each_entry_rcu(fdb, h, head, hlist) {
9a7b6ef9	347	if (ether_addr_equal(fdb->addr.addr, addr))
1da177e4 LT	348	return fdb;
	349	}
	350	return NULL;
	351	}
	352
	353	static struct net_bridge_fdb_entry fdb_create(struct hlist_head head,
	354	struct net_bridge_port *source,
03e9b64b	355	const unsigned char *addr)
1da177e4 LT	356	{
	357	struct net_bridge_fdb_entry *fdb;
	358
	359	fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
	360	if (fdb) {
	361	memcpy(fdb->addr.addr, addr, ETH_ALEN);
1da177e4	362	fdb->dst = source;
03e9b64b	363	fdb->is_local = 0;
03e9b64b	364	fdb->is_static = 0;
7cd8861a	365	fdb->updated = fdb->used = jiffies;
1158f762	366	hlist_add_head_rcu(&fdb->hlist, head);
1da177e4 LT	367	}
	368	return fdb;
	369	}
	370
	371	static int fdb_insert(struct net_bridge br, struct net_bridge_port source,
	372	const unsigned char *addr)
	373	{
	374	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	375	struct net_bridge_fdb_entry *fdb;
	376
	377	if (!is_valid_ether_addr(addr))
	378	return -EINVAL;
	379
	380	fdb = fdb_find(head, addr);
	381	if (fdb) {
9d6f229f	382	/* it is okay to have multiple ports with same
1da177e4 LT	383	* address, just use the first one.
1da177e4 LT	384	*/
9d6f229f	385	if (fdb->is_local)
1da177e4	386	return 0;
28a16c97	387	br_warn(br, "adding interface %s with same address "
1da177e4 LT	388	"as a received packet\n",
1da177e4 LT	389	source->dev->name);
31e8a49c	390	fdb_delete(br, fdb);
9d6f229f	391	}
1da177e4	392
03e9b64b	393	fdb = fdb_create(head, source, addr);
03e9b64b	394	if (!fdb)
1da177e4 LT	395	return -ENOMEM;
1da177e4 LT	396
03e9b64b	397	fdb->is_local = fdb->is_static = 1;
31e8a49c	398	fdb_notify(br, fdb, RTM_NEWNEIGH);
1da177e4 LT	399	return 0;
	400	}
	401
03e9b64b	402	/* Add entry for local address of interface */
1da177e4 LT	403	int br_fdb_insert(struct net_bridge br, struct net_bridge_port source,
	404	const unsigned char *addr)
	405	{
	406	int ret;
	407
	408	spin_lock_bh(&br->hash_lock);
	409	ret = fdb_insert(br, source, addr);
	410	spin_unlock_bh(&br->hash_lock);
	411	return ret;
	412	}
	413
	414	void br_fdb_update(struct net_bridge br, struct net_bridge_port source,
	415	const unsigned char *addr)
	416	{
	417	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	418	struct net_bridge_fdb_entry *fdb;
	419
	420	/* some users want to always flood. */
	421	if (hold_time(br) == 0)
	422	return;
	423
df1c0b84 SH	424	/* ignore packets unless we are using this port */
	425	if (!(source->state == BR_STATE_LEARNING \|\|
	426	source->state == BR_STATE_FORWARDING))
	427	return;
	428
664de48b	429	fdb = fdb_find_rcu(head, addr);
1da177e4 LT	430	if (likely(fdb)) {
	431	/* attempt to update an entry for a local interface */
	432	if (unlikely(fdb->is_local)) {
9d6f229f	433	if (net_ratelimit())
28a16c97	434	br_warn(br, "received packet on %s with "
	435	"own address as source address\n",
	436	source->dev->name);
1da177e4 LT	437	} else {
	438	/* fastpath: update of existing entry */
	439	fdb->dst = source;
7cd8861a	440	fdb->updated = jiffies;
1da177e4 LT	441	}
1da177e4 LT	442	} else {
f8ae737d	443	spin_lock(&br->hash_lock);
f58ee4e1	444	if (likely(!fdb_find(head, addr))) {
	445	fdb = fdb_create(head, source, addr);
	446	if (fdb)
31e8a49c	447	fdb_notify(br, fdb, RTM_NEWNEIGH);
f58ee4e1	448	}
1da177e4 LT	449	/* else we lose race and someone else inserts
	450	* it first, don't bother updating
	451	*/
f8ae737d	452	spin_unlock(&br->hash_lock);
1da177e4	453	}
1da177e4	454	}
b078f0df	455
	456	static int fdb_to_nud(const struct net_bridge_fdb_entry *fdb)
	457	{
	458	if (fdb->is_local)
	459	return NUD_PERMANENT;
	460	else if (fdb->is_static)
	461	return NUD_NOARP;
	462	else if (has_expired(fdb->dst->br, fdb))
	463	return NUD_STALE;
	464	else
	465	return NUD_REACHABLE;
	466	}
	467
31e8a49c	468	static int fdb_fill_info(struct sk_buff skb, const struct net_bridge br,
b078f0df	469	const struct net_bridge_fdb_entry *fdb,
15e47304	470	u32 portid, u32 seq, int type, unsigned int flags)
b078f0df	471	{
	472	unsigned long now = jiffies;
	473	struct nda_cacheinfo ci;
	474	struct nlmsghdr *nlh;
	475	struct ndmsg *ndm;
	476
15e47304	477	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
b078f0df	478	if (nlh == NULL)
	479	return -EMSGSIZE;
	480
b078f0df	481	ndm = nlmsg_data(nlh);
	482	ndm->ndm_family = AF_BRIDGE;
	483	ndm->ndm_pad1 = 0;
	484	ndm->ndm_pad2 = 0;
	485	ndm->ndm_flags = 0;
	486	ndm->ndm_type = 0;
43598813	487	ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex;
b078f0df	488	ndm->ndm_state = fdb_to_nud(fdb);
b078f0df	489
2eb812e6 DM	490	if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->addr))
2eb812e6 DM	491	goto nla_put_failure;
b078f0df	492	ci.ndm_used = jiffies_to_clock_t(now - fdb->used);
	493	ci.ndm_confirmed = 0;
	494	ci.ndm_updated = jiffies_to_clock_t(now - fdb->updated);
	495	ci.ndm_refcnt = 0;
2eb812e6 DM	496	if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
2eb812e6 DM	497	goto nla_put_failure;
b078f0df	498	return nlmsg_end(skb, nlh);
	499
	500	nla_put_failure:
	501	nlmsg_cancel(skb, nlh);
	502	return -EMSGSIZE;
	503	}
	504
	505	static inline size_t fdb_nlmsg_size(void)
	506	{
	507	return NLMSG_ALIGN(sizeof(struct ndmsg))
	508	+ nla_total_size(ETH_ALEN) /* NDA_LLADDR */
	509	+ nla_total_size(sizeof(struct nda_cacheinfo));
	510	}
	511
31e8a49c	512	static void fdb_notify(struct net_bridge *br,
31e8a49c	513	const struct net_bridge_fdb_entry *fdb, int type)
b078f0df	514	{
31e8a49c	515	struct net *net = dev_net(br->dev);
b078f0df	516	struct sk_buff *skb;
	517	int err = -ENOBUFS;
	518
	519	skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
	520	if (skb == NULL)
	521	goto errout;
	522
31e8a49c	523	err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
b078f0df	524	if (err < 0) {
	525	/* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
	526	WARN_ON(err == -EMSGSIZE);
	527	kfree_skb(skb);
	528	goto errout;
	529	}
	530	rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
	531	return;
	532	errout:
	533	if (err < 0)
	534	rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
	535	}
	536
	537	/* Dump information about entries, in response to GETNEIGH */
77162022 JF	538	int br_fdb_dump(struct sk_buff *skb,
	539	struct netlink_callback *cb,
	540	struct net_device *dev,
	541	int idx)
b078f0df	542	{
77162022 JF	543	struct net_bridge *br = netdev_priv(dev);
77162022 JF	544	int i;
b078f0df	545
77162022 JF	546	if (!(dev->priv_flags & IFF_EBRIDGE))
77162022 JF	547	goto out;
b078f0df	548
77162022 JF	549	for (i = 0; i < BR_HASH_SIZE; i++) {
	550	struct hlist_node *h;
	551	struct net_bridge_fdb_entry *f;
b078f0df	552
77162022 JF	553	hlist_for_each_entry_rcu(f, h, &br->hash[i], hlist) {
	554	if (idx < cb->args[0])
	555	goto skip;
	556
	557	if (fdb_fill_info(skb, br, f,
15e47304	558	NETLINK_CB(cb->skb).portid,
77162022 JF	559	cb->nlh->nlmsg_seq,
	560	RTM_NEWNEIGH,
	561	NLM_F_MULTI) < 0)
	562	break;
b078f0df	563	skip:
77162022	564	++idx;
b078f0df	565	}
b078f0df	566	}
b078f0df	567
77162022 JF	568	out:
77162022 JF	569	return idx;
b078f0df	570	}
36fd2b63	571
292d1398	572	/* Update (create or replace) forwarding database entry */
36fd2b63	573	static int fdb_add_entry(struct net_bridge_port source, const __u8 addr,
64af1bac	574	__u16 state, __u16 flags)
36fd2b63	575	{
	576	struct net_bridge *br = source->br;
	577	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	578	struct net_bridge_fdb_entry *fdb;
	579
	580	fdb = fdb_find(head, addr);
64af1bac	581	if (fdb == NULL) {
	582	if (!(flags & NLM_F_CREATE))
	583	return -ENOENT;
36fd2b63	584
64af1bac	585	fdb = fdb_create(head, source, addr);
	586	if (!fdb)
	587	return -ENOMEM;
31e8a49c	588	fdb_notify(br, fdb, RTM_NEWNEIGH);
64af1bac	589	} else {
	590	if (flags & NLM_F_EXCL)
	591	return -EEXIST;
292d1398	592	}
	593
	594	if (fdb_to_nud(fdb) != state) {
	595	if (state & NUD_PERMANENT)
	596	fdb->is_local = fdb->is_static = 1;
	597	else if (state & NUD_NOARP) {
	598	fdb->is_local = 0;
	599	fdb->is_static = 1;
	600	} else
	601	fdb->is_local = fdb->is_static = 0;
64af1bac	602
292d1398	603	fdb->updated = fdb->used = jiffies;
31e8a49c	604	fdb_notify(br, fdb, RTM_NEWNEIGH);
64af1bac	605	}
36fd2b63	606
36fd2b63	607	return 0;
	608	}
	609
	610	/* Add new permanent fdb entry with RTM_NEWNEIGH */
77162022 JF	611	int br_fdb_add(struct ndmsg ndm, struct net_device dev,
77162022 JF	612	unsigned char *addr, u16 nlh_flags)
36fd2b63	613	{
36fd2b63	614	struct net_bridge_port *p;
77162022	615	int err = 0;
36fd2b63	616
292d1398	617	if (!(ndm->ndm_state & (NUD_PERMANENT\|NUD_NOARP\|NUD_REACHABLE))) {
	618	pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
	619	return -EINVAL;
	620	}
	621
36fd2b63	622	p = br_port_get_rtnl(dev);
	623	if (p == NULL) {
	624	pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
	625	dev->name);
	626	return -EINVAL;
	627	}
	628
292d1398	629	if (ndm->ndm_flags & NTF_USE) {
	630	rcu_read_lock();
	631	br_fdb_update(p->br, p, addr);
	632	rcu_read_unlock();
	633	} else {
	634	spin_lock_bh(&p->br->hash_lock);
77162022	635	err = fdb_add_entry(p, addr, ndm->ndm_state, nlh_flags);
292d1398	636	spin_unlock_bh(&p->br->hash_lock);
292d1398	637	}
36fd2b63	638
	639	return err;
	640	}
	641
77162022	642	static int fdb_delete_by_addr(struct net_bridge_port p, u8 addr)
36fd2b63	643	{
	644	struct net_bridge *br = p->br;
	645	struct hlist_head *head = &br->hash[br_mac_hash(addr)];
	646	struct net_bridge_fdb_entry *fdb;
	647
	648	fdb = fdb_find(head, addr);
	649	if (!fdb)
	650	return -ENOENT;
	651
31e8a49c	652	fdb_delete(p->br, fdb);
36fd2b63	653	return 0;
	654	}
	655
	656	/* Remove neighbor entry with RTM_DELNEIGH */
77162022 JF	657	int br_fdb_delete(struct ndmsg ndm, struct net_device dev,
77162022 JF	658	unsigned char *addr)
36fd2b63	659	{
36fd2b63	660	struct net_bridge_port *p;
36fd2b63	661	int err;
36fd2b63	662
36fd2b63	663	p = br_port_get_rtnl(dev);
	664	if (p == NULL) {
	665	pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
	666	dev->name);
	667	return -EINVAL;
	668	}
	669
	670	spin_lock_bh(&p->br->hash_lock);
	671	err = fdb_delete_by_addr(p, addr);
	672	spin_unlock_bh(&p->br->hash_lock);
	673
	674	return err;
	675	}