Hi , 

I tried using the UDP GRO feature in DPDK recently and it did not see working. I understand the GRO for UDP is applicable only for fragmented packets, there is the following check in gro_udp4.c 

* Don't process non-fragment packet.

*/

if (!is_ipv4_fragment(ipv4_hdr))

There looks to be some conflict in the definition of RTE_PTYPE in rte_mbuf_ptype.h and the usage of this in GRO layer, rte_gro.c 

The below are the definitions, 

#define RTE_PTYPE_L4_UDP                    0x00000200

Below is the check in GRO layer, 

        ((ptype & RTE_PTYPE_L4_TCP) == RTE_PTYPE_L4_TCP) && \

        (RTE_ETH_IS_TUNNEL_PKT(ptype) == 0))

#define IS_IPV4_UDP_PKT(ptype) (RTE_ETH_IS_IPV4_HDR(ptype) && \

        ((ptype & RTE_PTYPE_L4_UDP) == RTE_PTYPE_L4_UDP) && \

So, for a fragmented UDP packet both RTE_PTYPE_L4_TCP & RTE_PTYPE_L4_UDP would be set and the GRO layer would be not able to interpret the packet type right. 

I am using rte_net_get_ptype API before the packet is being sent to the GRO subsystem as the DPDK PMD for the NIC I am using would not set the packet types as required by the GRO subsystem. 

I would like to contribute a patch for this bug if this indeed is an issue, I was thinking if the GRO subsystem is L4 fragmented then in the GRO layer invoked the appropriate handler, either gro_tcp4_reassemble or gro_ud4_reassemble. 

Please let me know if I am missing something here. 

Thanks,

Param.