Section "Flooding L2 domain" says, to avoid duplicated flooding, if skb->offload_fwd_mark is matched with dev->skb_mark, the kernel will drop the packet. However, the relevant code in __dev_queue_xmit compares skb->offload_fwd_mark with dev->offload_fwd_mark, not dev->skb_mark. I guess the text is wrong.
Signed-off-by: Ryota Ozaki <ozaki.ry...@gmail.com> --- Documentation/networking/switchdev.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/networking/switchdev.txt b/Documentation/networking/switchdev.txt index 31c3911..d4124a0 100644 --- a/Documentation/networking/switchdev.txt +++ b/Documentation/networking/switchdev.txt @@ -286,8 +286,8 @@ otherwise there will be duplicate packets on the wire. To avoid duplicate packets, the device/driver should mark a packet as already forwarded using skb->offload_fwd_mark. The same mark is set on the device ports in the domain using dev->offload_fwd_mark. If the skb->offload_fwd_mark -is non-zero and matches the forwarding egress port's dev->skb_mark, the kernel -will drop the skb right before transmit on the egress port, with the +is non-zero and matches the forwarding egress port's dev->offload_fwd_mark, +the kernel will drop the skb right before transmit on the egress port, with the understanding that the device already forwarded the packet on same egress port. The driver can use switchdev_port_fwd_mark_set() to set a globally unique mark for port's dev->offload_fwd_mark, based on the port's parent ID (switch ID) and -- 2.7.4
