From 7bdc66242de7f9cbe8dbb01757042dd18744d800 Mon Sep 17 00:00:00 2001 From: Gao Feng Date: Sun, 18 Sep 2016 10:52:25 +0800 Subject: [PATCH] netfilter: Enhance the codes used to get random once There are some codes which are used to get one random once in netfilter. We could use net_get_random_once to simplify these codes. Signed-off-by: Gao Feng Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_RATEEST.c | 6 +----- net/netfilter/xt_connlimit.c | 8 +------- net/netfilter/xt_recent.c | 7 ++----- 3 files changed, 4 insertions(+), 17 deletions(-) diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c index 515131f9e021..dbd6c4a12b97 100644 --- a/net/netfilter/xt_RATEEST.c +++ b/net/netfilter/xt_RATEEST.c @@ -24,7 +24,6 @@ static DEFINE_MUTEX(xt_rateest_mutex); #define RATEEST_HSIZE 16 static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly; static unsigned int jhash_rnd __read_mostly; -static bool rnd_inited __read_mostly; static unsigned int xt_rateest_hash(const char *name) { @@ -99,10 +98,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) } cfg; int ret; - if (unlikely(!rnd_inited)) { - get_random_bytes(&jhash_rnd, sizeof(jhash_rnd)); - rnd_inited = true; - } + net_get_random_once(&jhash_rnd, sizeof(jhash_rnd)); est = xt_rateest_lookup(info->name); if (est) { diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c index 99bbc829868d..b6dc322593a3 100644 --- a/net/netfilter/xt_connlimit.c +++ b/net/netfilter/xt_connlimit.c @@ -366,14 +366,8 @@ static int connlimit_mt_check(const struct xt_mtchk_param *par) unsigned int i; int ret; - if (unlikely(!connlimit_rnd)) { - u_int32_t rand; + net_get_random_once(&connlimit_rnd, sizeof(connlimit_rnd)); - do { - get_random_bytes(&rand, sizeof(rand)); - } while (!rand); - cmpxchg(&connlimit_rnd, 0, rand); - } ret = nf_ct_l3proto_try_module_get(par->family); if (ret < 0) { pr_info("cannot load conntrack support for " diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index d725a27743a1..e3b7a09b103e 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -110,7 +110,6 @@ static const struct file_operations recent_old_fops, recent_mt_fops; #endif static u_int32_t hash_rnd __read_mostly; -static bool hash_rnd_inited __read_mostly; static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr) { @@ -340,10 +339,8 @@ static int recent_mt_check(const struct xt_mtchk_param *par, int ret = -EINVAL; size_t sz; - if (unlikely(!hash_rnd_inited)) { - get_random_bytes(&hash_rnd, sizeof(hash_rnd)); - hash_rnd_inited = true; - } + net_get_random_once(&hash_rnd, sizeof(hash_rnd)); + if (info->check_set & ~XT_RECENT_VALID_FLAGS) { pr_info("Unsupported user space flags (%08x)\n", info->check_set); -- 2.20.1