samples/bpf: Fix MAC address swapping in xdp2_kern

[ Upstream commit 7a698edf95 ]

xdp2_kern rewrites and forwards packets out on the same interface.
Forwarding still works but rewrite got broken when xdp multibuffer
support has been added.

With xdp multibuffer a local copy of the packet has been introduced. The
MAC address is now swapped in the local copy, but the local copy in not
written back.

Fix MAC address swapping be adding write back of modified packet.

Fixes: 7722517422 ("samples/bpf: fixup some tools to be able to support xdp multibuffer")
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Link: https://lore.kernel.org/r/20221015213050.65222-1-gerhard@engleder-embedded.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Gerhard Engleder 2022-10-15 23:30:50 +02:00 committed by Greg Kroah-Hartman
parent 387ff72737
commit 5c0d14a6fb
1 changed files with 4 additions and 0 deletions

View File

@ -112,6 +112,10 @@ int xdp_prog1(struct xdp_md *ctx)
if (ipproto == IPPROTO_UDP) {
swap_src_dst_mac(data);
if (bpf_xdp_store_bytes(ctx, 0, pkt, sizeof(pkt)))
return rc;
rc = XDP_TX;
}