[PATCH net-next 04/11] ndisc: Introduce __ipv6_neigh_lookup_noref().
From: YOSHIFUJI Hideaki <hidden>
Date: 2013-01-17 17:42:08
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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: YOSHIFUJI Hideaki <redacted> --- include/net/ndisc.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index bbc938e..ec48f42 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h@@ -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;
--
1.7.9.5