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| author |   Lorenzo Bianconi <lorenzo@kernel.org> | 2022-05-25 11:44:27 +0200 |
|---|---|---|
| committer |   Andrii Nakryiko <andrii@kernel.org> | 2022-06-02 16:26:54 -0700 |
| commit | 200a89e3e88786b52bc1dd5f26a310c097f4c6a7 (patch) | |
| tree | cf15ebcfc2eb9b415a9bebe91457edf130b63120 /samples | |
| parent | libbpf: Fix determine_ptr_size() guessing (diff) | |
| download | linux-dev-200a89e3e88786b52bc1dd5f26a310c097f4c6a7.tar.xz linux-dev-200a89e3e88786b52bc1dd5f26a310c097f4c6a7.zip | |
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: 85bf1f51691c ("samples: bpf: Convert xdp_router_ipv4 to XDP samples helper")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/60bde5496d108089080504f58199bcf1143ea938.1653471558.git.lorenzo@kernel.org
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/bpf/xdp_router_ipv4.bpf.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/samples/bpf/xdp_router_ipv4.bpf.c b/samples/bpf/xdp_router_ipv4.bpf.c index 248119ca7938..0643330d1d2e 100644 --- a/samples/bpf/xdp_router_ipv4.bpf.c +++ b/samples/bpf/xdp_router_ipv4.bpf.c @@ -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; + } } } |