net: Helper to move packet data and metadata after skb_push/pull

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Lay groundwork for fixing BPF helpers available to TC(X) programs.

When skb_push() or skb_pull() is called in a TC(X) ingress BPF program, the
skb metadata must be kept in front of the MAC header. Otherwise, BPF
programs using the __sk_buff->data_meta pseudo-pointer lose access to it.

Introduce a helper that moves both metadata and a specified number of
packet data bytes together, suitable as a drop-in replacement for
memmove().

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251105-skb-meta-rx-path-v4-1-5ceb08a9b37b@cloudflare.com

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Jakub Sitnicki 2025-11-05 21:19:38 +01:00 • committed by Martin KaFai Lau

parent a0c3aefb08

commit 8989d328df

1 changed files with 75 additions and 0 deletions

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include/linux/skbuff.h

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