Add dl_type to flow metadata for correct interpretation of conntrack metadata

When a packet is sent to the controller, dl_type is not stored in the
'ofputil_packet_in_private'. When the packet is resumed, the flow's
dl_type is 0 and this leads to invalid value in ct_orig_tuple in the
pkt_metadata.

This patch adds the dl_type to the metadata so that conntrack
information can be interpreted correctly when packets are resumed.

This is a change from the ordinary practice, since flow_get_metadata() is
only supposed to deal with metadata and dl_type is not metadata.  It is
necessary when ct_state is involved, though, because ct_state only applies
in the case of particular Ethertypes (IPv4 and IPv6 currently), so we need
to add it as a kind of prerequisite.  (This isn't ideal; maybe we didn't
think through the ct_state mechanism carefully enough.)

Reported-by: Daniel Alvarez Sanchez <dalvarez@redhat.com>
Reported-at: https://mail.openvswitch.org/pipermail/ovs-dev/2017-October/339868.html
Signed-off-by: Daniel Alvarez <dalvarez@redhat.com>
Signed-off-by: Numan Siddique <nusiddiq@redhat.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/flow.c b/lib/flow.c
index b2b10aa48..4d2b7747a 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -1073,6 +1073,9 @@ flow_get_metadata(const struct flow *flow, struct match *flow_metadata)
 
     if (flow->ct_state != 0) {
         match_set_ct_state(flow_metadata, flow->ct_state);
+        /* Match dl_type since it is required for the later interpretation of
+         * the conntrack metadata. */
+        match_set_dl_type(flow_metadata, flow->dl_type);
         if (is_ct_valid(flow, NULL, NULL) && flow->ct_nw_proto != 0) {
             if (flow->dl_type == htons(ETH_TYPE_IP)) {
                 match_set_ct_nw_src(flow_metadata, flow->ct_nw_src);