Commit 84a797dd authored by Eric Dumazet's avatar Eric Dumazet Committed by Patrick McHardy
Browse files

netfilter: nfnetlink_queue: provide rcu enabled callbacks 



nenetlink_queue operations on SMP are not efficent if several queues are
used, because of nfnl_mutex contention when applications give packet
verdict.

Use new call_rcu field in struct nfnl_callback to advertize a callback
that is called under rcu_read_lock instead of nfnl_mutex.

On my 2x4x2 machine, I was able to reach 2.000.000 pps going through
user land returning NF_ACCEPT verdicts without losses, instead of less
than 500.000 pps before patch.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
CC: Florian Westphal <fw@strlen.de>
CC: Eric Leblond <eric@regit.org>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 6b75e3e8

net/netfilter/nfnetlink_queue.c

+12 −29
Original line number Diff line number Diff line
@@ -619,39 +619,26 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, 
	struct nfqnl_instance *queue;

	unsigned int verdict;

	struct nf_queue_entry *entry;

	int err;



	rcu_read_lock();

	queue = instance_lookup(queue_num);

	if (!queue) {

		err = -ENODEV;

		goto err_out_unlock;

	}

	if (!queue)

		return -ENODEV;



	if (queue->peer_pid != NETLINK_CB(skb).pid) {

		err = -EPERM;

		goto err_out_unlock;

	}

	if (queue->peer_pid != NETLINK_CB(skb).pid)

		return -EPERM;



	if (!nfqa[NFQA_VERDICT_HDR]) {

		err = -EINVAL;

		goto err_out_unlock;

	}

	if (!nfqa[NFQA_VERDICT_HDR])

		return -EINVAL;



	vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);

	verdict = ntohl(vhdr->verdict);



	if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) {

		err = -EINVAL;

		goto err_out_unlock;

	}

	if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT)

		return -EINVAL;



	entry = find_dequeue_entry(queue, ntohl(vhdr->id));

	if (entry == NULL) {

		err = -ENOENT;

		goto err_out_unlock;

	}

	rcu_read_unlock();

	if (entry == NULL)

		return -ENOENT;



	if (nfqa[NFQA_PAYLOAD]) {

		if (nfqnl_mangle(nla_data(nfqa[NFQA_PAYLOAD]),
@@ -664,10 +651,6 @@ nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, 


	nf_reinject(entry, verdict);

	return 0;



err_out_unlock:

	rcu_read_unlock();

	return err;

}



static int
@@ -780,9 +763,9 @@ err_out_unlock: 
}



static const struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = {

	[NFQNL_MSG_PACKET]	= { .call = nfqnl_recv_unsupp,

	[NFQNL_MSG_PACKET]	= { .call_rcu = nfqnl_recv_unsupp,

				    .attr_count = NFQA_MAX, },

	[NFQNL_MSG_VERDICT]	= { .call = nfqnl_recv_verdict,

	[NFQNL_MSG_VERDICT]	= { .call_rcu = nfqnl_recv_verdict,

				    .attr_count = NFQA_MAX,

				    .policy = nfqa_verdict_policy },

	[NFQNL_MSG_CONFIG]	= { .call = nfqnl_recv_config,

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