[ovs-dev] [PATCH v2] ovn-controller: Fix flow generation for container traffic.

[Gurucharan Shetty]

Okay. (I already committed this patch, so you probably need a rebase)

On Tue, Jul 28, 2015 at 3:42 PM, Ben Pfaff <blp at nicira.com> wrote:
> On Tue, Jul 28, 2015 at 01:44:42PM -0700, Ben Pfaff wrote:
>> On Fri, Jul 24, 2015 at 04:31:03PM -0700, Gurucharan Shetty wrote:
>> > In table 64, when a vlan tag is set on a packet
>> > destined to a container running inside a VM, we currently
>> > don't revert it. This has an unintended consequence for
>> > broadcast traffic when one endpoint of the braodcast
>> > traffic is a plain VM (without containers running inside) where
>> > the previously set tag would remain in the packets sent to the VM.
>> >
>> > This commit fixes the above problem by popping the VLAN
>> > and resetting the input port after outputting the packet
>> > with a vlan tag to a container logical port.
>> >
>> > Signed-off-by: Gurucharan Shetty <gshetty at nicira.com>
>>
>> Acked-by: Ben Pfaff <blp at nicira.com>
>
> The same bug is in my tunnel-key series, I'm folding the following into
> the final patch in that series.
>
> diff --git a/ovn/controller/physical.c b/ovn/controller/physical.c
> index 09b7a99..4c81bb2 100644
> --- a/ovn/controller/physical.c
> +++ b/ovn/controller/physical.c
> @@ -123,6 +123,14 @@ put_encapsulation(enum mf_field_id mff_ovn_geneve,
>      }
>  }
>
> +static void
> +put_stack(enum mf_field_id field, struct ofpact_stack *stack)
> +{
> +    stack->subfield.field = mf_from_id(field);
> +    stack->subfield.ofs = 0;
> +    stack->subfield.n_bits = stack->subfield.field->n_bits;
> +}
> +
>  void
>  physical_run(struct controller_ctx *ctx, enum mf_field_id mff_ovn_geneve,
>               const struct ovsrec_bridge *br_int, const char *this_chassis_id,
> @@ -301,9 +309,19 @@ physical_run(struct controller_ctx *ctx, enum mf_field_id mff_ovn_geneve,
>                  /* A packet might need to hair-pin back into its ingress
>                   * OpenFlow port (to a different logical port, which we already
>                   * checked back in table 34), so set the in_port to zero. */
> +                put_stack(MFF_IN_PORT, ofpact_put_STACK_PUSH(&ofpacts));
>                  put_load(0, MFF_IN_PORT, 0, 16, &ofpacts);
>              }
>              ofpact_put_OUTPUT(&ofpacts)->port = ofport;
> +            if (tag) {
> +                /* Revert the tag added to the packets headed to containers
> +                 * in the previous step. If we don't do this, the packets
> +                 * that are to be broadcasted to a VM in the same logical
> +                 * switch will also contain the tag. Also revert the zero'd
> +                 * in_port. */
> +                ofpact_put_STRIP_VLAN(&ofpacts);
> +                put_stack(MFF_IN_PORT, ofpact_put_STACK_POP(&ofpacts));
> +            }
>              ofctrl_add_flow(flow_table, 64, 100, &match, &ofpacts);
>          } else {
>              /* Table 32, priority 100.