Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 294188ae authored by Jan Engelhardt's avatar Jan Engelhardt Committed by Patrick McHardy
Browse files

netfilter: xtables: obtain random bytes earlier, in checkentry 

We can initialize the random hash bytes on checkentry. This is
preferable since it is outside the hot path.

Reference: http://bugzilla.netfilter.org/show_bug.cgi?id=621


Signed-off-by: default avatarJan Engelhardt <jengelh@medozas.de>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 5191d501

net/netfilter/xt_connlimit.c

+6 −11
Original line number Diff line number Diff line
@@ -40,15 +40,11 @@ struct xt_connlimit_data { 
	spinlock_t lock;

};



static u_int32_t connlimit_rnd;

static bool connlimit_rnd_inited;

static u_int32_t connlimit_rnd __read_mostly;

static bool connlimit_rnd_inited __read_mostly;



static inline unsigned int connlimit_iphash(__be32 addr)

{

	if (unlikely(!connlimit_rnd_inited)) {

		get_random_bytes(&connlimit_rnd, sizeof(connlimit_rnd));

		connlimit_rnd_inited = true;

	}

	return jhash_1word((__force __u32)addr, connlimit_rnd) & 0xFF;

}
@@ -59,11 +55,6 @@ connlimit_iphash6(const union nf_inet_addr *addr, 
	union nf_inet_addr res;

	unsigned int i;



	if (unlikely(!connlimit_rnd_inited)) {

		get_random_bytes(&connlimit_rnd, sizeof(connlimit_rnd));

		connlimit_rnd_inited = true;

	}



	for (i = 0; i < ARRAY_SIZE(addr->ip6); ++i)

		res.ip6[i] = addr->ip6[i] & mask->ip6[i];
@@ -226,6 +217,10 @@ static bool connlimit_mt_check(const struct xt_mtchk_param *par) 
	struct xt_connlimit_info *info = par->matchinfo;

	unsigned int i;



	if (unlikely(!connlimit_rnd_inited)) {

		get_random_bytes(&connlimit_rnd, sizeof(connlimit_rnd));

		connlimit_rnd_inited = true;

	}

	if (nf_ct_l3proto_try_module_get(par->family) < 0) {

		printk(KERN_WARNING "cannot load conntrack support for "

		       "address family %u\n", par->family);

net/netfilter/xt_recent.c

+8 −12
Original line number Diff line number Diff line
@@ -90,25 +90,17 @@ static struct proc_dir_entry *recent_proc_dir; 
static const struct file_operations recent_old_fops, recent_mt_fops;

#endif



static u_int32_t hash_rnd;

static bool hash_rnd_initted;

static u_int32_t hash_rnd __read_mostly;

static bool hash_rnd_inited __read_mostly;



static unsigned int recent_entry_hash4(const union nf_inet_addr *addr)

static inline unsigned int recent_entry_hash4(const union nf_inet_addr *addr)

{

	if (!hash_rnd_initted) {

		get_random_bytes(&hash_rnd, sizeof(hash_rnd));

		hash_rnd_initted = true;

	}

	return jhash_1word((__force u32)addr->ip, hash_rnd) &

	       (ip_list_hash_size - 1);

}



static unsigned int recent_entry_hash6(const union nf_inet_addr *addr)

static inline unsigned int recent_entry_hash6(const union nf_inet_addr *addr)

{

	if (!hash_rnd_initted) {

		get_random_bytes(&hash_rnd, sizeof(hash_rnd));

		hash_rnd_initted = true;

	}

	return jhash2((u32 *)addr->ip6, ARRAY_SIZE(addr->ip6), hash_rnd) &

	       (ip_list_hash_size - 1);

}
@@ -287,6 +279,10 @@ static bool recent_mt_check(const struct xt_mtchk_param *par) 
	unsigned i;

	bool ret = false;



	if (unlikely(!hash_rnd_inited)) {

		get_random_bytes(&hash_rnd, sizeof(hash_rnd));

		hash_rnd_inited = true;

	}

	if (hweight8(info->check_set &

		     (XT_RECENT_SET | XT_RECENT_REMOVE |

		      XT_RECENT_CHECK | XT_RECENT_UPDATE)) != 1)