On 07/13/2017 10:08 AM, Darrell Ball wrote:
On 7/13/17, 9:25 AM, "ovs-dev-boun...@openvswitch.org on behalf of Greg Rose" <ovs-dev-boun...@openvswitch.org on behalf of gvrose8...@gmail.com> wrote: When there is an established connection in direction A->B, it is possible to receive a packet on port B which then executes ct(commit,force) without first performing ct() - ie, a lookup. In this case, we would expect that this packet can delete the existing entry so that we can commit a connection with direction B->A. However, currently we only perform a check in skb_nfct_cached() for whether OVS_CS_F_TRACKED is set and OVS_CS_F_INVALID is not set, ie that a lookup previously occurred. In the above scenario, a lookup has not occurred but we should still be able to statelessly look up the existing entry and potentially delete the entry if it is in the opposite direction.This patch extends the check to also hint that if the action has theforce flag set, then we will lookup the existing entry so that the force check at the end of skb_nfct_cached has the ability to delete the connection.CC: d...@openvswitch.orgCC: Pravin Shalar <pshe...@nicira.com> Signed-off-by: Joe Stringer <j...@ovn.org> Signed-off-by: Greg Rose <gvrose8...@gmail.com> --- net/openvswitch/conntrack.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.cindex 08679eb..9041cf8 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -641,17 +641,21 @@ static bool skb_nfct_cached(struct net *net, ct = nf_ct_get(skb, &ctinfo); /* If no ct, check if we have evidence that an existing conntrack entry * might be found for this skb. This happens when we lose a skb->_nfct - * due to an upcall. If the connection was not confirmed, it is not - * cached and needs to be run through conntrack again. + * due to an upcall, or if the direction is being forced. If the + * connection was not confirmed, it is not cached and needs to be run + * through conntrack again. */ - if (!ct && key->ct_state & OVS_CS_F_TRACKED && + if ((!ct && (key->ct_state & OVS_CS_F_TRACKED) && !(key->ct_state & OVS_CS_F_INVALID) && - key->ct_zone == info->zone.id) { + key->ct_zone == info->zone.id) || + (!key->ct_state && info->force)) { ct = ovs_ct_find_existing(net, &info->zone, info->family, skb, !!(key->ct_state & OVS_CS_F_NAT_MASK)); if (ct) nf_ct_get(skb, &ctinfo); + else + return false; the above else case looks redundant since it maps to the following check if (!ct) return false; which services a superset of the code flow.
Sure, we can let it fall through... missed that. After waiting for more review I'll send a V2 patch. Thanks for the review Darrell - Greg
} if (!ct) return false; -- 1.8.3.1_______________________________________________dev mailing list d...@openvswitch.org https://urldefense.proofpoint.com/v2/url?u=https-3A__mail.openvswitch.org_mailman_listinfo_ovs-2Ddev&d=DwICAg&c=uilaK90D4TOVoH58JNXRgQ&r=BVhFA09CGX7JQ5Ih-uZnsw&m=5da6ykiSQJBoJXmpq6iVknmPAc5JDzlVngmp8j_xcXA&s=PsX-njQ_hFqy8P77KNEyX0i7u165p2Wrbg4uAYqfbGs&e=
