Commit 200a89e3 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Andrii Nakryiko
Browse files

sample: bpf: xdp_router_ipv4: Allow the kernel to send arp requests 



Forward the packet to the kernel if the gw router mac address is missing
in to trigger ARP discovery.

Fixes: 85bf1f51 ("samples: bpf: Convert xdp_router_ipv4 to XDP samples helper")
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/60bde5496d108089080504f58199bcf1143ea938.1653471558.git.lorenzo@kernel.org
parent 610cd93b

samples/bpf/xdp_router_ipv4.bpf.c

+9 −0
Original line number Diff line number Diff line
@@ -150,6 +150,15 @@ int xdp_router_ipv4_prog(struct xdp_md *ctx) 


				dest_mac = bpf_map_lookup_elem(&arp_table,

							       &prefix_value->gw);

				if (!dest_mac) {

					/* Forward the packet to the kernel in

					 * order to trigger ARP discovery for

					 * the default gw.

					 */

					if (rec)

						NO_TEAR_INC(rec->xdp_pass);

					return XDP_PASS;

				}

			}

		}