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author | David S. Miller <davem@davemloft.net> | 2011-12-28 15:06:58 -0500 |
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committer | David S. Miller <davem@davemloft.net> | 2011-12-28 15:06:58 -0500 |
commit | 2c2aba6c561ac425602f4a0be61422224cb87151 (patch) | |
tree | 30b5f2c40b823ca61e2e0930d5e98a89a83222bb /net/core/neighbour.c | |
parent | 32288eb4d940b10e40c6d4178fe3a40d1437d2f8 (diff) | |
download | op-kernel-dev-2c2aba6c561ac425602f4a0be61422224cb87151.zip op-kernel-dev-2c2aba6c561ac425602f4a0be61422224cb87151.tar.gz |
ipv6: Use universal hash for NDISC.
In order to perform a proper universal hash on a vector of integers,
we have to use different universal hashes on each vector element.
Which means we need 4 different hash randoms for ipv6.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/neighbour.c')
-rw-r--r-- | net/core/neighbour.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 4af151e..e287346 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -322,11 +322,18 @@ out_entries: goto out; } +static void neigh_get_hash_rnd(u32 *x) +{ + get_random_bytes(x, sizeof(*x)); + *x |= 1; +} + static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift) { size_t size = (1 << shift) * sizeof(struct neighbour *); struct neigh_hash_table *ret; struct neighbour __rcu **buckets; + int i; ret = kmalloc(sizeof(*ret), GFP_ATOMIC); if (!ret) @@ -343,8 +350,8 @@ static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift) } ret->hash_buckets = buckets; ret->hash_shift = shift; - get_random_bytes(&ret->hash_rnd, sizeof(ret->hash_rnd)); - ret->hash_rnd |= 1; + for (i = 0; i < NEIGH_NUM_HASH_RND; i++) + neigh_get_hash_rnd(&ret->hash_rnd[i]); return ret; } @@ -1828,7 +1835,7 @@ static int neightbl_fill_info(struct sk_buff *skb, struct neigh_table *tbl, rcu_read_lock_bh(); nht = rcu_dereference_bh(tbl->nht); - ndc.ndtc_hash_rnd = nht->hash_rnd; + ndc.ndtc_hash_rnd = nht->hash_rnd[0]; ndc.ndtc_hash_mask = ((1 << nht->hash_shift) - 1); rcu_read_unlock_bh(); |