[dpdk-dev] question about PKT_RX_IPV4_HDR_EXT

[Ivan Boule]

On 12/26/2013 10:46 PM, Wang, Shawn wrote:
> Hi:
>
> Can anyone explain more details about the rte_mbuf ol_flag : PKT_RX_IPV4_HDR_EXT?
> The document said “RX packet with extended IPv4 header.”
> But what is the extended IPv4 header looks like? What is the difference with normal IPv4 header?
> Can anyone give me an example?
>
> Thanks a lot.
> Wang, Shawn
Hi,

A extended IPv4 header is a IPv4 header with additional options, whose
total header size is greater than 20 bytes. Intel 1GbE and 10Gbe
Ethernet controllers are able to recognize such packets, and, in this 
case,set a
dedicated flag into the RX descriptor where they store the packet.
Then, to supply this hardware-detected packet characteristics to the 
upper-level application,
the RX functions of DPDK PollMode Drivers of the 1GbE and 10Gbe Ethernet 
controllers set the
PKT_RX_IPV4_HDR_EXT generic flag into the mbuf that contains the packet.

Best regards,
Ivan

-- 
Ivan Boule
6WIND Development Engineer