Re: [dpdk-dev] [RFC] ethdev: add generic MAC address rewrite actions

[Jack MIN <jackmin@mellanox.com>]

On Tue, Aug 21, 2018 at 01:44:32PM +0530, Rahul Lakkireddy wrote:
> On Tuesday, August 08/14/18, 2018 at 14:45:45 +0530, Jack MIN wrote:
> > On Mon, Aug 13, 2018 at 03:38:18PM +0530, Rahul Lakkireddy wrote:
> > > On Tuesday, August 08/07/18, 2018 at 14:20:10 +0000, Jack Min wrote:
> > > > There is a need to offload rewrite MAC address for both destination and source
> > > > from the matched flow
> > > > 
> > > > The proposed actions could make above easily achieved
> > > > 
> > > 
> > > +1.
> > > 
> > > We're also looking to offload these actions. In addition, we also have
> > > a requirement to offload an action to swap the source and destination
> > > MAC addresses (i.e. source MAC address will get overwritten with the
> > > destination MAC address and vice-versa).
> > > 
> > Hey,
> > 
> > Just want to know in which specific scenario we need to swap MAC address ?
> > 
> 
> Sorry for the delay in response.
> 
> This action is needed to offload loopback mode; where the hardware
> will automatically swap the source and destination MAC before looping
> back the packet.
> 
> Also, MAC swap can be used in conjunction with the other rewrite actions
> to achieve MAC Layer Transparent NAT. When used in this way, the MAC
> addresses will be swapped before the source or destination MAC address
> is rewritten and NAT is performed.
> 
Thank you, Rahul. 
It sounds reasonable to have RTE_FLOW_ACTION_TYPE_MAC_SWAP action.

Could you please make a new RFC for this ?

At this moment we haven't enough resource to implement it so a separated
RFC could be better to manage.

What do you think?

-Jack

> Thanks,
> Rahul
> 
> > > Could you please add one more action RTE_FLOW_ACTION_TYPE_MAC_SWAP
> > > to achieve this? This action will not take any arguments. Let us
> > > know your thoughts.
> > > 
> > > Thanks,
> > > Rahul
> > > 
> > > > 
> > > > Signed-off-by: Xiaoyu Min <jackmin@mellanox.com<mailto:jackmin@mellanox.com>>
> > > > ---
> > > > lib/librte_ethdev/rte_flow.h | 32 ++++++++++++++++++++++++++++++++
> > > > 1 file changed, 32 insertions(+)
> > > > 
> > > > diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> > > > index f8ba71cdb..4a51ab2a3 100644
> > > > --- a/lib/librte_ethdev/rte_flow.h
> > > > +++ b/lib/librte_ethdev/rte_flow.h
> > > > @@ -1505,6 +1505,26 @@ enum rte_flow_action_type {
> > > >          * error.
> > > >          */
> > > >         RTE_FLOW_ACTION_TYPE_NVGRE_DECAP,
> > > > +
> > > > +       /**
> > > > +        * Set source MAC address from matched flow.
> > > > +        *
> > > > +        * If flow pattern does not define a valid RTE_FLOW_ITEM_TYPE_ETH,
> > > > +        * the PMD should return a RTE_FLOW_ERROR_TYPE_ACTION error.
> > > > +        *
> > > > +        * See struct rte_flow_action_set_mac.
> > > > +        */
> > > > +       RTE_FLOW_ACTION_TYPE_SET_MAC_SRC,
> > > > +
> > > > +       /**
> > > > +        * Set destination MAC address from matched flow.
> > > > +        *
> > > > +        * If flow pattern does not define a valid RTE_FLOW_ITEM_TYPE_ETH,
> > > > +        * the PMD should return a RTE_FLOW_ERROR_TYPE_ACTION error.
> > > > +        *
> > > > +        * See struct rte_flow_action_set_mac.
> > > > +        */
> > > > +       RTE_FLOW_ACTION_TYPE_SET_MAC_DST,
> > > > };
> > > > 
> > > > /**
> > > > @@ -1868,6 +1888,18 @@ struct rte_flow_action_nvgre_encap {
> > > >         struct rte_flow_item *definition;
> > > > };
> > > > 
> > > > +/**
> > > > + * @warning
> > > > + * @b EXPERIMENTAL: this structure may change without prior notice
> > > > + *
> > > > + * RTE_FLOW_ACTION_TYPE_SET_MAC
> > > > + *
> > > > + * Set MAC address from the matched flow
> > > > + */
> > > > +struct rte_flow_action_set_mac {
> > > > +       uint8_t mac_addr[ETHER_ADDR_LEN];
> > > > +};
> > > > +
> > > > /*
> > > >   * Definition of a single action.
> > > >   *
> > > > --
> > > > 2.17.1