|SUCCESS| net/ice: fix L2TPv2 outer MAC address in training packet

[dpdklab at iol.unh.edu]

Test-Label: ai-code-review
Test-Status: SUCCESS
https://dpdk.org/patch/162857

_AI Code Review_

=== Patch Review: series.patch (via Claude) ===
Review date: 2026-04-08

commit 733640dae75e ("net/ice: support L2TPv2 flow pattern matching")
Author: Shaiq Wani <shaiq.wani at intel.com>

net/ice: fix L2TPv2 outer MAC address in training packet

This patch addresses incorrect placement of outer MAC addresses in L2TPv2
training packets and adds L2TPV2 tunnel type detection during pattern
pre-scan.

> diff --git a/drivers/net/intel/ice/base/ice_fdir.c b/drivers/net/intel/ice/base/ice_fdir.c
> index 2c0cb99854..e1d8b65972 100644
> --- a/drivers/net/intel/ice/base/ice_fdir.c
> +++ b/drivers/net/intel/ice/base/ice_fdir.c
> @@ -4599,16 +4599,16 @@ ice_fdir_get_gen_prgm_pkt(struct ice_hw *hw, struct ice_fdir_fltr *input,
>  				     input->ip.v6.tc);
>  		break;
>  	case ICE_FLTR_PTYPE_NONF_IPV4_L2TPV2_CONTROL:
> -		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
> -		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
> +		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
> +		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
>  					input->ext_data_outer.src_mac);
>  		ice_pkt_insert_u16(loc, ICE_IPV4_L2TPV2_LEN_SESS_ID_OFFSET,
>  				   input->l2tpv2_data.session_id);
>  		break;
>  	case ICE_FLTR_PTYPE_NONF_IPV4_L2TPV2:
>  	case ICE_FLTR_PTYPE_NONF_IPV4_L2TPV2_PPP:
> -		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
> -		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
> +		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
> +		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
>  					input->ext_data_outer.src_mac);
>  		flags_version = BE16_TO_CPU(input->l2tpv2_data.flags_version);
>  		if (flags_version & ICE_L2TPV2_FLAGS_LEN) {
> @@ -4622,16 +4622,16 @@ ice_fdir_get_gen_prgm_pkt(struct ice_hw *hw, struct ice_fdir_fltr *input,
>  		}
>  		break;
>  	case ICE_FLTR_PTYPE_NONF_IPV6_L2TPV2_CONTROL:
> -		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
> -		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
> +		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
> +		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
>  					input->ext_data_outer.src_mac);
>  		ice_pkt_insert_u16(loc, ICE_IPV6_L2TPV2_LEN_SESS_ID_OFFSET,
>  				   input->l2tpv2_data.session_id);
>  		break;
>  	case ICE_FLTR_PTYPE_NONF_IPV6_L2TPV2:
>  	case ICE_FLTR_PTYPE_NONF_IPV6_L2TPV2_PPP:
> -		ice_pkt_insert_mac_addr(loc, input->ext_data_outer.dst_mac);
> -		ice_pkt_insert_mac_addr(loc + ETH_ALEN,
> +		ice_pkt_insert_mac_addr(pkt, input->ext_data_outer.dst_mac);
> +		ice_pkt_insert_mac_addr(pkt + ETH_ALEN,
>  					input->ext_data_outer.src_mac);
>  		flags_version = BE16_TO_CPU(input->l2tpv2_data.flags_version);
>  		if (flags_version & ICE_L2TPV2_FLAGS_LEN) {

The fix correctly changes from 'loc' to 'pkt' for MAC address insertion.
Can we confirm that 'pkt' still points to offset 0 of the Ethernet header
in all six L2TPv2 cases? Does any preceding code in
ice_fdir_get_gen_prgm_pkt() modify the 'pkt' pointer before reaching
these cases?

> diff --git a/drivers/net/intel/ice/ice_fdir_filter.c b/drivers/net/intel/ice/ice_fdir_filter.c
> index 3522d77123..1cbc613020 100644
> --- a/drivers/net/intel/ice/ice_fdir_filter.c
> +++ b/drivers/net/intel/ice/ice_fdir_filter.c
> @@ -1911,6 +1911,8 @@ ice_fdir_parse_pattern(__rte_unused struct ice_adapter *ad,
>  	for (item = pattern; item->type != RTE_FLOW_ITEM_TYPE_END; item++) {
>  		if (item->type == RTE_FLOW_ITEM_TYPE_VXLAN)
>  			tunnel_type = ICE_FDIR_TUNNEL_TYPE_VXLAN;
> +		if (item->type == RTE_FLOW_ITEM_TYPE_L2TPV2)
> +			tunnel_type = ICE_FDIR_TUNNEL_TYPE_L2TPV2;

Does this code overwrite tunnel_type if both VXLAN and L2TPV2 items are
present in a pattern? Would such a flow pattern be invalid and rejected
elsewhere, or could this result in incorrect tunnel_type selection?