提交 a42b99a6 编写于 作者: F Florian Westphal 提交者: Pablo Neira Ayuso

netfilter: avoid get_random_bytes calls

All these users need an initial seed value for jhash, prandom is
perfectly fine.  This avoids draining the entropy pool where
its not strictly required.

nfnetlink_log did not use the random value at all.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
上级 8cf4d6a2
......@@ -28,8 +28,6 @@
#include <linux/proc_fs.h>
#include <linux/security.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/netfilter/nf_log.h>
......@@ -75,7 +73,6 @@ struct nfulnl_instance {
};
#define INSTANCE_BUCKETS 16
static unsigned int hash_init;
static int nfnl_log_net_id __read_mostly;
......@@ -1066,11 +1063,6 @@ static int __init nfnetlink_log_init(void)
{
int status = -ENOMEM;
/* it's not really all that important to have a random value, so
* we can do this from the init function, even if there hasn't
* been that much entropy yet */
get_random_bytes(&hash_init, sizeof(hash_init));
netlink_register_notifier(&nfulnl_rtnl_notifier);
status = nfnetlink_subsys_register(&nfulnl_subsys);
if (status < 0) {
......
......@@ -164,7 +164,7 @@ static int nft_hash_init(const struct nft_set *set,
unsigned int cnt, i;
if (unlikely(!nft_hash_rnd_initted)) {
get_random_bytes(&nft_hash_rnd, 4);
nft_hash_rnd = prandom_u32();
nft_hash_rnd_initted = true;
}
......
......@@ -100,7 +100,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
int ret;
if (unlikely(!rnd_inited)) {
get_random_bytes(&jhash_rnd, sizeof(jhash_rnd));
jhash_rnd = prandom_u32();
rnd_inited = true;
}
......
......@@ -229,7 +229,7 @@ static int connlimit_mt_check(const struct xt_mtchk_param *par)
u_int32_t rand;
do {
get_random_bytes(&rand, sizeof(rand));
rand = prandom_u32();
} while (!rand);
cmpxchg(&connlimit_rnd, 0, rand);
}
......
......@@ -177,7 +177,7 @@ dsthash_alloc_init(struct xt_hashlimit_htable *ht,
/* initialize hash with random val at the time we allocate
* the first hashtable entry */
if (unlikely(!ht->rnd_initialized)) {
get_random_bytes(&ht->rnd, sizeof(ht->rnd));
ht->rnd = prandom_u32();
ht->rnd_initialized = true;
}
......
......@@ -334,7 +334,7 @@ static int recent_mt_check(const struct xt_mtchk_param *par,
size_t sz;
if (unlikely(!hash_rnd_inited)) {
get_random_bytes(&hash_rnd, sizeof(hash_rnd));
hash_rnd = prandom_u32();
hash_rnd_inited = true;
}
if (info->check_set & ~XT_RECENT_VALID_FLAGS) {
......
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