cipso: Relax too much careful cipso hash function. (5e0f8923) · Commits · 戴 / test

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@openvz.org> Acked-by:

Paul Moore <paul.moore@hp.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/cipso_ipv4.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -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);

Admin message