Re: Correct tc-vlan usage

[Jiri Pirko <jiri@resnulli.us>]

Wed, Apr 15, 2020 at 07:59:06PM CEST, olteanv@gmail.com wrote:
>Hi,
>
>I am trying to use tc-vlan to create a set of asymmetric tagging
>rules: push VID X on egress, and pop VID Y on ingress. I am using
>tc-vlan specifically because regular VLAN interfaces are unfit for
>this purpose - the VID that gets pushed by the 8021q driver is the
>same as the one that gets popped.
>The rules look like this:
>
># tc filter show dev eno2 ingress
>filter protocol 802.1Q pref 49150 flower chain 0
>filter protocol 802.1Q pref 49150 flower chain 0 handle 0x1
>  vlan_id 103
>  dst_mac 00:04:9f:63:35:eb
>  not_in_hw
>        action order 1: vlan  pop pipe
>         index 6 ref 1 bind 1
>
>filter protocol 802.1Q pref 49151 flower chain 0
>filter protocol 802.1Q pref 49151 flower chain 0 handle 0x1
>  vlan_id 102
>  dst_mac 00:04:9f:63:35:eb
>  not_in_hw
>        action order 1: vlan  pop pipe
>         index 5 ref 1 bind 1
>
>filter protocol 802.1Q pref 49152 flower chain 0
>filter protocol 802.1Q pref 49152 flower chain 0 handle 0x1
>  vlan_id 101
>  dst_mac 00:04:9f:63:35:eb
>  not_in_hw
>        action order 1: vlan  pop pipe
>         index 4 ref 1 bind 1
>
># tc filter show dev eno2 egress
>filter protocol all pref 49150 flower chain 0
>filter protocol all pref 49150 flower chain 0 handle 0x1
>  dst_mac 00:04:9f:63:35:ec
>  not_in_hw
>        action order 1: vlan  push id 102 protocol 802.1Q priority 0 pipe
>         index 3 ref 1 bind 1
>
>filter protocol all pref 49151 flower chain 0
>filter protocol all pref 49151 flower chain 0 handle 0x1
>  dst_mac 00:04:9f:63:35:eb
>  not_in_hw
>        action order 1: vlan  push id 102 protocol 802.1Q priority 0 pipe
>         index 2 ref 1 bind 1
>
>filter protocol all pref 49152 flower chain 0
>filter protocol all pref 49152 flower chain 0 handle 0x1
>  dst_mac 00:04:9f:63:35:ea
>  not_in_hw
>        action order 1: vlan  push id 102 protocol 802.1Q priority 0 pipe
>         index 1 ref 1 bind 1
>
>My problem is that the VLAN tags are discarded by the network
>interface's RX filter:
>
># ethtool -S eno2
>     SI VLAN nomatch u-cast discards: 1280
>
>and this is because nobody calls .ndo_vlan_rx_add_vid for these VLANs
>(only the 8021q driver does). This makes me think that I am using the
>tc-vlan driver incorrectly. What step am I missing?

Hmm, that is a good point. Someone should add the vid to the filter. I
believe that "someone" should be the driver in case of flow_offload.



>
>Thanks,
>-Vladimir