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Commit 17f2f52b authored by Florian Westphal's avatar Florian Westphal Committed by Patrick McHardy
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netfilter: ipt_MASQUERADE: remove redundant rwlock 



The lock "protects" an assignment and a comparision of an integer.
When the caller of device_cmp() evaluates the result, nat->masq_index
may already have been changed (regardless if the lock is there or not).

So, the lock either has to be held during nf_ct_iterate_cleanup(),
or can be removed.

This does the latter.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 10662aa3

net/ipv4/netfilter/ipt_MASQUERADE.c

+1 −11
Original line number Diff line number Diff line
@@ -27,9 +27,6 @@ MODULE_LICENSE("GPL"); 
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");

MODULE_DESCRIPTION("Xtables: automatic-address SNAT");



/* Lock protects masq region inside conntrack */

static DEFINE_RWLOCK(masq_lock);



/* FIXME: Multiple targets. --RR */

static bool masquerade_tg_check(const struct xt_tgchk_param *par)

{
@@ -79,9 +76,7 @@ masquerade_tg(struct sk_buff *skb, const struct xt_target_param *par) 
		return NF_DROP;

	}



	write_lock_bh(&masq_lock);

	nat->masq_index = par->out->ifindex;

	write_unlock_bh(&masq_lock);



	/* Transfer from original range. */

	newrange = ((struct nf_nat_range)
@@ -97,16 +92,11 @@ static int 
device_cmp(struct nf_conn *i, void *ifindex)

{

	const struct nf_conn_nat *nat = nfct_nat(i);

	int ret;



	if (!nat)

		return 0;



	read_lock_bh(&masq_lock);

	ret = (nat->masq_index == (int)(long)ifindex);

	read_unlock_bh(&masq_lock);



	return ret;

	return nat->masq_index == (int)(long)ifindex;

}



static int masq_device_event(struct notifier_block *this,