[ovs-discuss] [ovs-dev] [OVN] OVN doesn't work using OVS 2.8.1 on Centos 7.3 using conntrack

[Ben Pfaff]

On Tue, Oct 24, 2017 at 11:07:58PM +0200, Daniel Alvarez Sanchez wrote:
> Hi guys,
> 
> Great job Numan!
> As we discussed over IRC, the patch below may make more sense.
> It essentially sets the dl_type so that when packet comes from the
> controller, it matches
> a valid type and OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4 is not added.
> Maybe what Numan proposed and this patch could be a good combination but I
> think
> that we definitely need to set the dl_type as it's later checked in
> pkt_metadata_from_flow()
> and it'll be zero there otherwise.
> What do you guys think? I have tried the patch below and the kernel error
> is not shown
> anymore when issuing DHCP requests.
> 
> 
> diff --git a/lib/flow.c b/lib/flow.c
> index b2b10aa..62b948f 100644
> --- a/lib/flow.c
> +++ b/lib/flow.c
> @@ -1073,6 +1073,7 @@ 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_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);

This patch seems reasonable too.

I recommend adding a comment above it to explain what's going on,
because dl_type is not a metadata field and it's confusing to deal with
it in a context that's supposed to be all about metadata.  I guess the
comment would essentially say that dl_type is essential to the
interpretation of the conntrack metadata.