netdev - [PATCH][CIPSO]: Relax too much careful cipso hash function.

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Message-ID: <4829937D.9070409@openvz.org>
Date:	Tue, 13 May 2008 17:11:25 +0400
From:	Pavel Emelyanov <xemul@...nvz.org>
To:	David Miller <davem@...emloft.net>, Paul Moore <paul.moore@...com>
CC:	Linux Netdev List <netdev@...r.kernel.org>
Subject: [PATCH][CIPSO]: Relax too much careful cipso hash function.

The cipso_v4_cache is allocated to contain CIPSO_V4_CACHE_BUCKETS
buckets. The CIPSO_V4_CACHE_BUCKETS = 1 << CIPSO_V4_CACHE_BUCKETBITS,
where CIPSO_V4_CACHE_BUCKETBITS = 7.

The bucket-selection function for this hash is calculated like this:

  bkt = hash & (CIPSO_V4_CACHE_BUCKETBITS - 1);
                                     ^^^

i.e. picking only 4 buckets of possible 128 :)

Signed-off-by: Pavel Emelyanov <xemul@...nvz.org>

---
 net/ipv4/cipso_ipv4.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 05afb57..2c0e457 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -338,7 +338,7 @@ static int cipso_v4_cache_check(const unsigned char *key,
 		return -ENOENT;
 
 	hash = cipso_v4_map_cache_hash(key, key_len);
-	bkt = hash & (CIPSO_V4_CACHE_BUCKETBITS - 1);
+	bkt = hash & (CIPSO_V4_CACHE_BUCKETS - 1);
 	spin_lock_bh(&cipso_v4_cache[bkt].lock);
 	list_for_each_entry(entry, &cipso_v4_cache[bkt].list, list) {
 		if (entry->hash == hash &&
@@ -417,7 +417,7 @@ int cipso_v4_cache_add(const struct sk_buff *skb,
 	atomic_inc(&secattr->cache->refcount);
 	entry->lsm_data = secattr->cache;
 
-	bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETBITS - 1);
+	bkt = entry->hash & (CIPSO_V4_CACHE_BUCKETS - 1);
 	spin_lock_bh(&cipso_v4_cache[bkt].lock);
 	if (cipso_v4_cache[bkt].size < cipso_v4_cache_bucketsize) {
 		list_add(&entry->list, &cipso_v4_cache[bkt].list);
--
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