[PATCH net-next v8 0/3] net: gro: remove network_header use, move p->{flush/flush_id} calculations to L4

[Richard Gobert]

The cb fields network_offset and inner_network_offset are used instead of
skb->network_header throughout GRO.

These fields are then leveraged in the next commit to remove flush_id state
from napi_gro_cb, and stateful code in {ipv6,inet}_gro_receive which may be
unnecessarily complicated due to encapsulation support in GRO. These fields
are checked in L4 instead.

3rd patch adds tests for different flush_id flows in GRO.

v7 -> v8:
 - Remove network_header use in gro
 - Re-send commits after the dependent patch to net was applied
 - v7:
   https://lore.kernel.org/all/20240412155533.115507-1-richardbgobert@xxxxxxxxx/

v6 -> v7:
 - Moved bug fixes to a separate submission in net
 - Added UDP fwd benchmark
 - v6:
   https://lore.kernel.org/all/20240410153423.107381-1-richardbgobert@xxxxxxxxx/

v5 -> v6:
 - Write inner_network_offset in vxlan and geneve
 - Ignore is_atomic when DF=0
 - v5:
   https://lore.kernel.org/all/20240408141720.98832-1-richardbgobert@xxxxxxxxx/

v4 -> v5:
 - Add 1st commit - flush id checks in udp_gro_receive segment which can be
   backported by itself
 - Add TCP measurements for the 5th commit
 - Add flush id tests to ensure flush id logic is preserved in GRO
 - Simplify gro_inet_flush by removing a branch
 - v4:
   https://lore.kernel.org/all/202420325182543.87683-1-richardbgobert@xxxxxxxxx/

v3 -> v4:
 - Fix code comment and commit message typos
 - v3:
   https://lore.kernel.org/all/f939c84a-2322-4393-a5b0-9b1e0be8ed8e@xxxxxxxxx/

v2 -> v3:
 - Use napi_gro_cb instead of skb->{offset}
 - v2:
   https://lore.kernel.org/all/2ce1600b-e733-448b-91ac-9d0ae2b866a4@xxxxxxxxx/

v1 -> v2:
 - Pass p_off in *_gro_complete to fix UDP bug
 - Remove more conditionals and memory fetches from inet_gro_flush
 - v1:
   https://lore.kernel.org/netdev/e1d22505-c5f8-4c02-a997-64248480338b@xxxxxxxxx/

Richard Gobert (3):
  net: gro: use cb instead of skb->network_header
  net: gro: move L3 flush checks to tcp_gro_receive and udp_gro_receive_segment
  selftests/net: add flush id selftests

 include/net/gro.h                 |  75 +++++++++++++--
 net/core/gro.c                    |   3 -
 net/ipv4/af_inet.c                |  45 +--------
 net/ipv4/tcp_offload.c            |  18 +---
 net/ipv4/udp_offload.c            |  10 +-
 net/ipv6/ip6_offload.c            |  16 +---
 net/ipv6/tcpv6_offload.c          |   3 +-
 tools/testing/selftests/net/gro.c | 147 ++++++++++++++++++++++++++++++
 8 files changed, 225 insertions(+), 92 deletions(-)

-- 
2.36.1