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Commit ac3175fe authored by YOSHIFUJI Hideaki / 吉藤英明's avatar YOSHIFUJI Hideaki / 吉藤英明 Committed by David S. Miller
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ndisc: Introduce __ipv6_neigh_lookup_noref(). 



This function, which looks up neighbour entry for an IPv6 address
without touching refcnt, will be used for patches to remove
dependency on rt->n (neighbour entry in rt6_info).

Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent dd0cbf29

include/net/ndisc.h

+15 −7
Original line number Diff line number Diff line
@@ -148,14 +148,13 @@ static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, _ 
		(p32[3] * hash_rnd[3]));

}



static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)

static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)

{

	struct neigh_hash_table *nht;

	const u32 *p32 = pkey;

	struct neighbour *n;

	u32 hash_val;



	rcu_read_lock_bh();

	nht = rcu_dereference_bh(nd_tbl.nht);

	hash_val = ndisc_hashfn(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);

	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
@@ -164,12 +163,21 @@ static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, cons 
		u32 *n32 = (u32 *) n->primary_key;

		if (n->dev == dev &&

		    ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) |

		     (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0) {

			if (!atomic_inc_not_zero(&n->refcnt))

				n = NULL;

			break;

		     (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0)

			return n;

	}



	return NULL;

}



static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)

{

	struct neighbour *n;



	rcu_read_lock_bh();

	n = __ipv6_neigh_lookup_noref(dev, pkey);

	if (n && !atomic_inc_not_zero(&n->refcnt))

		n = NULL;

	rcu_read_unlock_bh();



	return n;