On Thu, Nov 6, 2014 at 8:06 AM, Tom Herbert <therb...@google.com> wrote: > On Wed, Nov 5, 2014 at 10:16 PM, Sathya Perla <sathya.pe...@emulex.com> wrote: >>> -----Original Message----- >>> From: Tom Herbert [mailto:therb...@google.com] >>> >>> On Wed, Nov 5, 2014 at 6:15 PM, David Miller <da...@davemloft.net> >>> wrote: >>> > From: Joe Stringer <joestrin...@nicira.com> >>> > Date: Wed, 5 Nov 2014 17:06:46 -0800 >>> > >>> >> My impression was that the changes are more likely to be >>> >> hardware-specific (like the i40e changes) rather than software-specific, >>> >> like changes that might be integrated into the helper. >>> > >>> > I think there is more commonality amongst hardware capabilities, >>> > and this is why I want the helper to play itself out. >>> > >>> >> That said, I can rework for one helper. The way I see it would be the >>> >> same code as these patches, as "vxlan_gso_check(struct sk_buff *)" in >>> >> drivers/net/vxlan.c which would be called from each driver. Is that what >>> >> you had in mind? >>> > >>> > Yes. >>> >>> Note that this code is not VXLAN specific, it will also accept NVGRE >>> and GRE/UDP with keyid and TEB. I imagine all these cases should be >>> indistinguishable to the hardware so they probably just work (which >>> would be cool!). It might be better to name and locate the helper >>> function to reflect that. >> >> Tom, I'm confused as to how the value of (skb_inner_mac_header(skb) - >> skb_transport_header(skb)) >> would be the same for VxLAN and NVGRE encapsulated packets. Wouldn't this >> value be 16 for VxLAN >> and 8 for NVGRE? >> > The inner headers are reset in iptunnel_handle_offloads. This is > called in the xmit encapsulation functions (GRE, fou, VXLAN, etc.) > before adding in encapsulation headers (skb_push), so the > mac_inner_header will point to the encapsulation payload, i.e. the > encapsulated packet. This should not change after being set, although > inner network and inner transport can. The headers are only set on the > first encapsulation, so with nested tunnels the inner headers point to > the innermost encapsulated packet. Since VXLAN and NVGRE have same > size of encapsulation (8 UDP + 8 header), skb_inner_mac_header(skb) > - skb_transport_header(skb) should always be 16.
Tom, NVGRE is not encapsulated in UDP and it is not 16 bytes. http://tools.ietf.org/html/draft-sridharan-virtualization-nvgre-06 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
