Commit c7f79f26 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

openvswitch: prepare for stolen verdict coming from conntrack and nat engine 



At this time, conntrack either returns NF_ACCEPT or NF_DROP.
To improve debuging it would be nice to be able to replace NF_DROP
verdict with NF_DROP_REASON() helper,

This helper releases the skb instantly (so drop_monitor can pinpoint
precise location) and returns NF_STOLEN.

Prepare call sites to deal with this before introducing such changes
in conntrack and nat core.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Reviewed-by: default avatarAaron Conole <aconole@redhat.om>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent aba43bdf

net/openvswitch/conntrack.c

+37 −10
Original line number Diff line number Diff line
@@ -679,6 +679,8 @@ static int ovs_ct_nat(struct net *net, struct sw_flow_key *key, 
		action |= BIT(NF_NAT_MANIP_DST);



	err = nf_ct_nat(skb, ct, ctinfo, &action, &info->range, info->commit);

	if (err != NF_ACCEPT)

		return err;



	if (action & BIT(NF_NAT_MANIP_SRC))

		ovs_nat_update_key(key, skb, NF_NAT_MANIP_SRC);
@@ -697,6 +699,22 @@ static int ovs_ct_nat(struct net *net, struct sw_flow_key *key, 
}

#endif



static int verdict_to_errno(unsigned int verdict)

{

	switch (verdict & NF_VERDICT_MASK) {

	case NF_ACCEPT:

		return 0;

	case NF_DROP:

		return -EINVAL;

	case NF_STOLEN:

		return -EINPROGRESS;

	default:

		break;

	}



	return -EINVAL;

}



/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if

 * not done already.  Update key with new CT state after passing the packet

 * through conntrack.
@@ -735,7 +753,7 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, 


		err = nf_conntrack_in(skb, &state);

		if (err != NF_ACCEPT)

			return -ENOENT;

			return verdict_to_errno(err);



		/* Clear CT state NAT flags to mark that we have not yet done

		 * NAT after the nf_conntrack_in() call.  We can actually clear
@@ -762,9 +780,12 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, 
		 * the key->ct_state.

		 */

		if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&

		    (nf_ct_is_confirmed(ct) || info->commit) &&

		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {

			return -EINVAL;

		    (nf_ct_is_confirmed(ct) || info->commit)) {

			int err = ovs_ct_nat(net, key, info, skb, ct, ctinfo);



			err = verdict_to_errno(err);

			if (err)

				return err;

		}



		/* Userspace may decide to perform a ct lookup without a helper
@@ -795,9 +816,12 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, 
		 * - When committing an unconfirmed connection.

		 */

		if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :

					      info->commit) &&

		    nf_ct_helper(skb, ct, ctinfo, info->family) != NF_ACCEPT) {

			return -EINVAL;

					      info->commit)) {

			int err = nf_ct_helper(skb, ct, ctinfo, info->family);



			err = verdict_to_errno(err);

			if (err)

				return err;

		}



		if (nf_ct_protonum(ct) == IPPROTO_TCP &&
@@ -1001,10 +1025,9 @@ static int ovs_ct_commit(struct net *net, struct sw_flow_key *key, 
	/* This will take care of sending queued events even if the connection

	 * is already confirmed.

	 */

	if (nf_conntrack_confirm(skb) != NF_ACCEPT)

		return -EINVAL;

	err = nf_conntrack_confirm(skb);



	return 0;

	return verdict_to_errno(err);

}



/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
@@ -1039,6 +1062,10 @@ int ovs_ct_execute(struct net *net, struct sk_buff *skb, 
	else

		err = ovs_ct_lookup(net, key, info, skb);



	/* conntrack core returned NF_STOLEN */

	if (err == -EINPROGRESS)

		return err;



	skb_push_rcsum(skb, nh_ofs);

	if (err)

		ovs_kfree_skb_reason(skb, OVS_DROP_CONNTRACK);