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igc: AF_XDP zero-copy metadata adjust breaks SKBs on XDP_PASS

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Driver already implicitly supports XDP metadata access in AF_XDP
zero-copy mode, as xsk_buff_pool's xp_alloc() naturally set xdp_buff
data_meta equal data.

This works fine for XDP and AF_XDP, but if a BPF-prog adjust via
bpf_xdp_adjust_meta() and choose to call XDP_PASS, then igc function
igc_construct_skb_zc() will construct an invalid SKB packet. The
function correctly include the xdp->data_meta area in the memcpy, but
forgot to pull header to take metasize into account.

Fixes: fc9df2a0b5 ("igc: Enable RX via AF_XDP zero-copy")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Nechama Kraus <nechamax.kraus@linux.intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
This commit is contained in:
Jesper Dangaard Brouer 2021-11-15 21:36:25 +01:00 committed by Tony Nguyen
parent 196073f9c4
commit 4fa8fcd344
1 changed files with 3 additions and 1 deletions
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4
drivers/net/ethernet/intel/igc/igc_main.c
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@ -2448,8 +2448,10 @@ static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring,
skb_reserve(skb, xdp->data_meta - xdp->data_hard_start);
memcpy(__skb_put(skb, totalsize), xdp->data_meta, totalsize);
if (metasize)
if (metasize) {
skb_metadata_set(skb, metasize);
__skb_pull(skb, metasize);
}
return skb;
}