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
This commit is contained in:
Daniel Borkmann 2020-10-11 01:40:01 +02:00 committed by Alexei Starovoitov
parent ac53a0d310
commit dd2ce6a537
2 changed files with 14 additions and 6 deletions

View File

@ -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.

View File

@ -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.