Subject: Re: [iwl-next v2 2/2] ice: tc: allow ip_proto matching

From: Michal Swiatkowski <[email-masked]>
Date: Thu, 14 Mar 2024 12:03:41 +0100

On Thu, Feb 22, 2024 at 01:39:56PM +0100, Michal Swiatkowski wrote:
> Add new matching type for ip_proto.
> 
> Use it in the same lookup type as for TTL. In hardware it has the same
> protocol ID, but different offset.
> 
> Example command to add filter with ip_proto:
> $tc filter add dev eth10 ingress protocol ip flower ip_proto icmp \
>  skip_sw action mirred egress redirect dev eth0
> 
> Reviewed-by: Jedrzej Jagielski <[email-masked]>
> Signed-off-by: Michal Swiatkowski <[email-masked]>
> ---
>  drivers/net/ethernet/intel/ice/ice_tc_lib.c | 17 +++++++++++++++--
>  drivers/net/ethernet/intel/ice/ice_tc_lib.h |  1 +
>  2 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c
> index 49ed5fd7db10..f7c0f62fb730 100644
> --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c
> +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c
> @@ -78,7 +78,8 @@ ice_tc_count_lkups(u32 flags, struct ice_tc_flower_lyr_2_4_hdrs *headers,
>  		     ICE_TC_FLWR_FIELD_DEST_IPV6 | ICE_TC_FLWR_FIELD_SRC_IPV6))
>  		lkups_cnt++;
>  
> -	if (flags & (ICE_TC_FLWR_FIELD_IP_TOS | ICE_TC_FLWR_FIELD_IP_TTL))
> +	if (flags & (ICE_TC_FLWR_FIELD_IP_TOS | ICE_TC_FLWR_FIELD_IP_TTL |
> +		     ICE_TC_FLWR_FIELD_IP_PROTO))
>  		lkups_cnt++;

There is an issue here. In case of ipv6 it shouldn't be count as there is no
support for next header in ipv6.

Example command to reproduce the problem:
tc filter add dev eth0 ingress protocol ipv6 prio 103 flower skip_sw \
	dst_mac fa:16:3e:13:e9:a1 ip_proto udp src_port 547 dst_port 546 \
	dst_ip fe80::/64 action drop

Filter won't be added because of mismatch between filled and counted
lookups.

I will send v3 with fix.

Thanks,
Michal

>  
>  	/* are L2TPv3 options specified? */
> @@ -530,7 +531,8 @@ ice_tc_fill_rules(struct ice_hw *hw, u32 flags,
>  	}
>  
>  	if (headers->l2_key.n_proto == htons(ETH_P_IP) &&
> -	    (flags & (ICE_TC_FLWR_FIELD_IP_TOS | ICE_TC_FLWR_FIELD_IP_TTL))) {
> +	    (flags & (ICE_TC_FLWR_FIELD_IP_TOS | ICE_TC_FLWR_FIELD_IP_TTL |
> +		      ICE_TC_FLWR_FIELD_IP_PROTO))) {
>  		list[i].type = ice_proto_type_from_ipv4(inner);
>  
>  		if (flags & ICE_TC_FLWR_FIELD_IP_TOS) {
> @@ -545,6 +547,13 @@ ice_tc_fill_rules(struct ice_hw *hw, u32 flags,
>  				headers->l3_mask.ttl;
>  		}
>  
> +		if (flags & ICE_TC_FLWR_FIELD_IP_PROTO) {
> +			list[i].h_u.ipv4_hdr.protocol =
> +				headers->l3_key.ip_proto;
> +			list[i].m_u.ipv4_hdr.protocol =
> +				headers->l3_mask.ip_proto;
> +		}
> +
>  		i++;
>  	}
>  
> @@ -1515,7 +1524,11 @@ ice_parse_cls_flower(struct net_device *filter_dev, struct ice_vsi *vsi,
>  
>  		headers->l2_key.n_proto = cpu_to_be16(n_proto_key);
>  		headers->l2_mask.n_proto = cpu_to_be16(n_proto_mask);
> +
> +		if (match.key->ip_proto)
> +			fltr->flags |= ICE_TC_FLWR_FIELD_IP_PROTO;
>  		headers->l3_key.ip_proto = match.key->ip_proto;
> +		headers->l3_mask.ip_proto = match.mask->ip_proto;
>  	}
>  
>  	if (flow_rule_match_key(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
> diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.h b/drivers/net/ethernet/intel/ice/ice_tc_lib.h
> index 65d387163a46..856f371d0687 100644
> --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.h
> +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.h
> @@ -34,6 +34,7 @@
>  #define ICE_TC_FLWR_FIELD_VLAN_PRIO		BIT(27)
>  #define ICE_TC_FLWR_FIELD_CVLAN_PRIO		BIT(28)
>  #define ICE_TC_FLWR_FIELD_VLAN_TPID		BIT(29)
> +#define ICE_TC_FLWR_FIELD_IP_PROTO		BIT(30)
>  
>  #define ICE_TC_FLOWER_MASK_32   0xFFFFFFFF
>  
> -- 
> 2.42.0
>