From 5bd5f7b3aee8d0d9cef658c47c7f7544e657ae96 Mon Sep 17 00:00:00 2001 From: Jiayu Hu Date: Wed, 16 Jan 2019 10:13:42 +0800 Subject: [PATCH] doc: add GRO limitations in programmers guide This patch adds GRO limitations in the programmer guide. Fixes: 2c900d09055e ("doc: add GRO guide") Cc: stable@dpdk.org Signed-off-by: Jiayu Hu Acked-by: Konstantin Ananyev --- .../generic_receive_offload_lib.rst | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/doc/guides/prog_guide/generic_receive_offload_lib.rst b/doc/guides/prog_guide/generic_receive_offload_lib.rst index 9c6a4d08c8..5b3fb91c8c 100644 --- a/doc/guides/prog_guide/generic_receive_offload_lib.rst +++ b/doc/guides/prog_guide/generic_receive_offload_lib.rst @@ -191,3 +191,22 @@ Header fields deciding if packets are neighbors include: ignore IPv4 ID fields for the packets whose DF bit is 1. Additionally, packets which have different value of DF bit can't be merged. + +GRO Library Limitations +----------------------- + +- GRO library uses MBUF->l2_len/l3_len/l4_len/outer_l2_len/ + outer_l3_len/packet_type to get protocol headers for the + input packet, rather than parsing the packet header. Therefore, + before call GRO APIs to merge packets, user applications + must set MBUF->l2_len/l3_len/l4_len/outer_l2_len/outer_l3_len/ + packet_type to the same values as the protocol headers of the + packet. + +- GRO library doesn't support to process the packets with IPv4 + Options or VLAN tagged. + +- GRO library just supports to process the packet organized + in a single MBUF. If the input packet consists of multiple + MBUFs (i.e. chained MBUFs), GRO reassembly behaviors are + unknown. -- 2.20.1