diff options
| author |   Daniel Borkmann <daniel@iogearbox.net> | 2020-10-11 01:40:01 +0200 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-10-11 10:21:04 -0700 |
| commit | dd2ce6a5373c6f5c830be54be10775458a8bd312 (patch) | |
| tree | 7940f3cc43157998f60f63a252289217166abd21 /tools/include | |
| parent | Merge branch 'bpf-llvm-reg-alloc-patterns' (diff) | |
| download | wireguard-linux-dd2ce6a5373c6f5c830be54be10775458a8bd312.tar.xz wireguard-linux-dd2ce6a5373c6f5c830be54be10775458a8bd312.zip | |
bpf: Improve bpf_redirect_neigh helper description
Follow-up to address David's feedback that we should better describe internals
of the bpf_redirect_neigh() helper.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: David Ahern <dsahern@gmail.com>
Link: https://lore.kernel.org/bpf/20201010234006.7075-2-daniel@iogearbox.net
Diffstat (limited to 'tools/include')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 42d2df799397..4272cc53d478 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3679,10 +3679,14 @@ union bpf_attr { * Redirect the packet to another net device of index *ifindex* * and fill in L2 addresses from neighboring subsystem. This helper * is somewhat similar to **bpf_redirect**\ (), except that it - * fills in e.g. MAC addresses based on the L3 information from - * the packet. This helper is supported for IPv4 and IPv6 protocols. + * populates L2 addresses as well, meaning, internally, the helper + * performs a FIB lookup based on the skb's networking header to + * get the address of the next hop and then relies on the neighbor + * lookup for the L2 address of the nexthop. + * * The *flags* argument is reserved and must be 0. The helper is - * currently only supported for tc BPF program types. + * currently only supported for tc BPF program types, and enabled + * for IPv4 and IPv6 protocols. * Return * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. |