[PATCH nf-next v7 0/3] Add IPIP flowtable SW acceleration

[Lorenzo Bianconi <lorenzo@kernel.org>]

Introduce SW acceleration for IPIP tunnels in the netfilter flowtable
infrastructure. This series introduces basic infrastructure to
accelerate other tunnel types (e.g. IP6IP6).

---
Changes in v7:
- Introduce sw acceleration for tx path of IPIP tunnels
- Rely on exact match during flowtable entry lookup
- Fix typos
- Link to v6: https://lore.kernel.org/r/20250818-nf-flowtable-ipip-v6-0-eda90442739c@kernel.org

Changes in v6:
- Rebase on top of nf-next main branch
- Link to v5: https://lore.kernel.org/r/20250721-nf-flowtable-ipip-v5-0-0865af9e58c6@kernel.org

Changes in v5:
- Rely on __ipv4_addr_hash() to compute the hash used as encap ID
- Remove unnecessary pskb_may_pull() in nf_flow_tuple_encap()
- Add nf_flow_ip4_ecanp_pop utility routine
- Link to v4: https://lore.kernel.org/r/20250718-nf-flowtable-ipip-v4-0-f8bb1c18b986@kernel.org

Changes in v4:
- Use the hash value of the saddr, daddr and protocol of outer IP header as
  encapsulation id.
- Link to v3: https://lore.kernel.org/r/20250703-nf-flowtable-ipip-v3-0-880afd319b9f@kernel.org

Changes in v3:
- Add outer IP header sanity checks
- target nf-next tree instead of net-next
- Link to v2: https://lore.kernel.org/r/20250627-nf-flowtable-ipip-v2-0-c713003ce75b@kernel.org

Changes in v2:
- Introduce IPIP flowtable selftest
- Link to v1: https://lore.kernel.org/r/20250623-nf-flowtable-ipip-v1-1-2853596e3941@kernel.org

---
Lorenzo Bianconi (3):
      net: netfilter: Add IPIP flowtable rx sw acceleration
      net: netfilter: Add IPIP flowtable tx sw acceleration
      selftests: netfilter: nft_flowtable.sh: Add IPIP flowtable selftest

 include/linux/netdevice.h                          |  16 +++
 include/net/netfilter/nf_flow_table.h              |  26 +++++
 net/ipv4/ipip.c                                    |  29 +++++
 net/netfilter/nf_flow_table_core.c                 |  10 ++
 net/netfilter/nf_flow_table_ip.c                   | 118 ++++++++++++++++++++-
 net/netfilter/nft_flow_offload.c                   |  79 ++++++++++++--
 .../selftests/net/netfilter/nft_flowtable.sh       |  40 +++++++
 7 files changed, 307 insertions(+), 11 deletions(-)
---
base-commit: d1d7998df9d7d3ee20bcfc876065fa897b11506d
change-id: 20250623-nf-flowtable-ipip-1b3d7b08d067

Best regards,
-- 
Lorenzo Bianconi <lorenzo@kernel.org>