[PATCH net-next v2] openvswitch: Allow attaching helper in later commit
From: Yi-Hung Wei <hidden>
Date: 2019-10-04 16:38:12
This patch allows to attach conntrack helper to a confirmed conntrack entry. Currently, we can only attach alg helper to a conntrack entry when it is in the unconfirmed state. This patch enables an use case that we can firstly commit a conntrack entry after it passed some initial conditions. After that the processing pipeline will further check a couple of packets to determine if the connection belongs to a particular application, and attach alg helper to the connection in a later stage. Signed-off-by: Yi-Hung Wei <redacted> --- v1->v2, Use logical OR instead of bitwise OR as Dave suggested. --- net/openvswitch/conntrack.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 05249eb45082..df9c80bf621d 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c@@ -971,6 +971,8 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, ct = nf_ct_get(skb, &ctinfo); if (ct) { + bool add_helper = false; + /* Packets starting a new connection must be NATted before the * helper, so that the helper knows about the NAT. We enforce * this by delaying both NAT and helper calls for unconfirmed
@@ -988,16 +990,17 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, } /* Userspace may decide to perform a ct lookup without a helper - * specified followed by a (recirculate and) commit with one. - * Therefore, for unconfirmed connections which we will commit, - * we need to attach the helper here. + * specified followed by a (recirculate and) commit with one, + * or attach a helper in a later commit. Therefore, for + * connections which we will commit, we may need to attach + * the helper here. */ - if (!nf_ct_is_confirmed(ct) && info->commit && - info->helper && !nfct_help(ct)) { + if (info->commit && info->helper && !nfct_help(ct)) { int err = __nf_ct_try_assign_helper(ct, info->ct, GFP_ATOMIC); if (err) return err; + add_helper = true; /* helper installed, add seqadj if NAT is required */ if (info->nat && !nfct_seqadj(ct)) {
@@ -1007,11 +1010,13 @@ static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key, } /* Call the helper only if: - * - nf_conntrack_in() was executed above ("!cached") for a - * confirmed connection, or + * - nf_conntrack_in() was executed above ("!cached") or a + * helper was just attached ("add_helper") for a confirmed + * connection, or * - When committing an unconfirmed connection. */ - if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) && + if ((nf_ct_is_confirmed(ct) ? !cached || add_helper : + info->commit) && ovs_ct_helper(skb, info->family) != NF_ACCEPT) { return -EINVAL; }
--
2.7.4