On Wed, Aug 24, 2016 at 9:37 AM, David Ahern <d...@cumulusnetworks.com> wrote:
> On 8/24/16 10:28 AM, pravin shelar wrote:
>>> How do you feel about implementing the do_output() idea I suggested above?
>>> I'm happy to provide testing and review.
>>
>> I am not sure about changing do_output(). why not just use same scheme
>> to track mpls header in OVS datapath as done in mpls device?
>>
>
> was just replying with the same.
>
> Something like this should be able to handle multiple labels. The inner
> network header is set once and the outer one pointing to MPLS is adjusted
> each time a label is pushed:
>
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 1ecbd7715f6d..0f37b17e3a73 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -162,10 +162,16 @@ static int push_mpls(struct sk_buff *skb, struct
> sw_flow_key *key,
> if (skb_cow_head(skb, MPLS_HLEN) < 0)
> return -ENOMEM;
>
> + if (!skb->inner_protocol) {
> + skb_set_inner_network_header(skb, skb->mac_len);
> + skb_set_inner_protocol(skb, skb->protocol);
> + }
> +
> skb_push(skb, MPLS_HLEN);
> memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
> skb->mac_len);
> skb_reset_mac_header(skb);
> + skb_set_network_header(skb, skb->mac_len);
>
> new_mpls_lse = (__be32 *)skb_mpls_header(skb);
> *new_mpls_lse = mpls->mpls_lse;
> @@ -173,8 +179,7 @@ static int push_mpls(struct sk_buff *skb, struct
> sw_flow_key *key,
> skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);
>
> update_ethertype(skb, eth_hdr(skb), mpls->mpls_ethertype);
> - if (!skb->inner_protocol)
> - skb_set_inner_protocol(skb, skb->protocol);
> +
> skb->protocol = mpls->mpls_ethertype;
>
> invalidate_flow_key(key);
>
>
>
>
> If it does, what else needs to be changed in OVS to handle the network layer
> now pointing to the MPLS labels?
>
You also need to change pop_mpls().
Anyways I was thinking about the neigh output functions skb pull
issue, where it is using network-header offset. Can we use mac_len?
this way we would not use any inner offsets for MPLS skb and current
scheme used by OVS datapath works.
