diff mbox series

[bpf-next,1/6] bpf: improve bpf_redirect_neigh helper description

Message ID 20201008213148.26848-2-daniel@iogearbox.net (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series [bpf-next,1/6] bpf: improve bpf_redirect_neigh helper description | expand

Commit Message

Daniel Borkmann Oct. 8, 2020, 9:31 p.m. UTC 
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>
---
 include/uapi/linux/bpf.h       | 10 +++++++---
 tools/include/uapi/linux/bpf.h | 10 +++++++---
 2 files changed, 14 insertions(+), 6 deletions(-)

Comments

David Ahern Oct. 8, 2020, 10 p.m. UTC | #1 
On 10/8/20 2:31 PM, Daniel Borkmann wrote:
> 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>
> ---
>  include/uapi/linux/bpf.h       | 10 +++++++---
>  tools/include/uapi/linux/bpf.h | 10 +++++++---
>  2 files changed, 14 insertions(+), 6 deletions(-)
> 

Looks good to me. Thanks,

Reviewed-by: David Ahern <dsahern@gmail.com>
diff mbox series

Patch

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index d83561e8cd2c..8e8941535c28 100644
--- a/include/uapi/linux/bpf.h
+++ b/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.
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index d83561e8cd2c..8e8941535c28 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.