Commit 7cda76d8 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Daniel Borkmann
Browse files

veth: Allow jumbo frames in xdp mode 



Allow increasing the MTU over page boundaries on veth devices
if the attached xdp program declares to support xdp fragments.

Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Acked-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/d5dc039c3d4123426e7023a488c449181a7bc57f.1646989407.git.lorenzo@kernel.org
parent 718a18a0

drivers/net/veth.c

+8 −3
Original line number Diff line number Diff line
@@ -1528,9 +1528,14 @@ static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, 
			goto err;

		}



		max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -

			  peer->hard_header_len -

			  SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

		max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -

			  peer->hard_header_len;

		/* Allow increasing the max_mtu if the program supports

		 * XDP fragments.

		 */

		if (prog->aux->xdp_has_frags)

			max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;



		if (peer->mtu > max_mtu) {

			NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");

			err = -ERANGE;