Re: [PATCH net v2 1/2] net: keep the TCP fixed-ID flags on the header they describe

[sashiko-bot@kernel.org]

> Commit 3271f19bf7b9 ("net: gso: restore ids of outer ip headers
> correctly") made SKB_GSO_TCP_FIXEDID describe the outermost IPv4 header
> and added SKB_GSO_TCP_FIXEDID_INNER for the inner header of an
> encapsulated packet. Every path that adds or removes a header then has to
> move the flags, and none does. A TCP stream that GRO merged with fixed
> IDs and that is forwarded into an IPIP tunnel, or into an ESP tunnel mode
> SA with crypto offload, is segmented with one outer ID for all segments
> and with incrementing inner IDs. Decapsulation leaves the state of the
> removed outer header on the new outer one, and the inner header of a GRE
> or UDP tunnel, which segmentation reads at encap_level 0, gets the state
> of the outer header.
> 
> Let SKB_GSO_TCP_FIXEDID describe the innermost IPv4 header again, as it
> did before that commit, and replace SKB_GSO_TCP_FIXEDID_INNER with
> SKB_GSO_TCP_FIXEDID_OUTER for the outer header of an encapsulated
> packet. A new outer header then has no flag and gets incrementing IDs,
> so encapsulation needs no change, and decapsulation clears the outer
> flag in iptunnel_pull_offloads() and bpf_skb_net_shrink(). Convert mlx5
> and sfc, the two drivers that use the inner flag.
> 
> Fixes: 3271f19bf7b9 ("net: gso: restore ids of outer ip headers correctly")
> Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
> Signed-off-by: Julius Bairaktaris <julius@bairaktaris.de>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1794139176.git.julius@bairaktaris.de?part=1