Re: [dpdk-dev] [PATCH v1 4/4] net/iavf: support FDIR for IP fragment packet

["Li, Xiaoyun" <xiaoyun.li@intel.com>]

Hi

> -----Original Message-----
> From: Guo, Jia <jia.guo@intel.com>
> Sent: Wednesday, March 17, 2021 11:12
> To: orika@nvidia.com; Zhang, Qi Z <qi.z.zhang@intel.com>; Xing, Beilei
> <beilei.xing@intel.com>; Li, Xiaoyun <xiaoyun.li@intel.com>; Wu, Jingjing
> <jingjing.wu@intel.com>
> Cc: Zhang, Yuying <yuying.zhang@intel.com>; Xu, Ting <ting.xu@intel.com>;
> dev@dpdk.org; Guo, Jia <jia.guo@intel.com>
> Subject: [PATCH v1 4/4] net/iavf: support FDIR for IP fragment packet
> 
> New FDIR parsing are added to handle the fragmented IPv4/IPv6 packet.
> 
> Signed-off-by: Ting Xu <ting.xu@intel.com>
> Signed-off-by: Jeff Guo <jia.guo@intel.com>
> ---
>  drivers/net/iavf/iavf_fdir.c         | 278 ++++++++++++++++++---------
>  drivers/net/iavf/iavf_generic_flow.h |   5 +
>  2 files changed, 190 insertions(+), 93 deletions(-)
> 
> diff --git a/drivers/net/iavf/iavf_fdir.c b/drivers/net/iavf/iavf_fdir.c index
> e3f3b5f22a..348d423081 100644
> --- a/drivers/net/iavf/iavf_fdir.c
> +++ b/drivers/net/iavf/iavf_fdir.c
> @@ -34,7 +34,7 @@
<snip>
> 
>  	uint8_t  ipv6_addr_mask[16] = {
>  		0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, @@ -528,12
> +534,6 @@ iavf_fdir_parse_pattern(__rte_unused struct iavf_adapter *ad,
>  	};
> 
>  	for (item = pattern; item->type != RTE_FLOW_ITEM_TYPE_END; item++)
> {
> -		if (item->last) {

You can't directly remove the check. If users use "last" for items like RTE_FLOW_ITEM_TYPE_ETH. The driver doesn't support that.

> -			rte_flow_error_set(error, EINVAL,
> -					RTE_FLOW_ERROR_TYPE_ITEM, item,
> -					"Not support range");
> -		}
> -
>  		item_type = item->type;
> 
<snip>
> +			if (ipv4_mask->hdr.version_ihl ||
> +			    ipv4_mask->hdr.total_length ||
> +			    ipv4_mask->hdr.hdr_checksum) {
> +				rte_flow_error_set(error, EINVAL,
> +
> RTE_FLOW_ERROR_TYPE_ITEM,
> +						   item, "Invalid IPv4 mask.");
> +				return -rte_errno;
> +			}
> 
> -				rte_memcpy(hdr->buffer,
> -					&ipv4_spec->hdr,
> -					sizeof(ipv4_spec->hdr));

The ipv4_mask is checked. But what about ipv4_last?
What if users set a rule which includes "last" for hdr.version_ihl? The code doesn't process that and not err return.
You should block all situations in ipv4_last except for ipv4_last->hdr.fragment_offset.

<snip>
> +
> +			if (ipv4_mask->hdr.packet_id == UINT16_MAX ||
> +			    ipv4_mask->hdr.fragment_offset == UINT16_MAX) {

And I don't understand your logic here.
Only if ipv4_mask->hdr.fragment_offset and ipv4_mask->hdr.packet_id Are UINT16_MAX, you process this case. But what about other cases? Shouldn't those cases return err like not supported?
And the mask for fragment_offset shouldn't be 0xffff (UINT16_MAX), it should be 0x3fff (RTE_IPV4_HDR_OFFSET_MASK | RTE_IPV4_HDR_MF_FLAG). Because only the last 14 bits matters. The other 2 bits are reserved bit and DF bit, it doesn't matter if it's fragment packets or not.

> +				if (ipv4_last &&
> +				    ipv4_spec->hdr.packet_id == 0 &&
> +				    ipv4_last->hdr.packet_id == 0xffff)

And I don't understand this part too. I thought it's a fragment rule and non-fragment rule. Why is this related to packet_id? And what about fragment_offset spec and last?
In ovs usercase, the rule for fragment packets is like
flow create 0 ingress pattern eth / ipv4 src is xxx dst is xxx fragment_offset spec 0x8 fragment_offset last 0x2000 fragment_offset mask 0x3fff / end actions queue index 1 / end

And the rule for non-fragment rule is like:
flow create 0 ingress pattern eth / ipv4 src is xxx dst is xxx fragment_offset spec 0 fragment_offset mask 0x3fff / end actions queue index 1 / end
or
flow create 0 ingress pattern eth / ipv4 src is xxx dst is xxx fragment_offset mask 0x3fff / end actions queue index 1 / end

How can your codes here make sure the rules behave correctly?

> +					spec_all_pid = true;
> +
> +				/* All IPv4 fragment packet has the same
> +				 * ethertype, if the spec is for all invalid
> +				 * packet id, set the ethertype into input set.
> +				 */
> +				input_set |= spec_all_pid ?
> +					IAVF_INSET_ETHERTYPE :
> +					IAVF_INSET_IPV4_ID;
> +
> +				if (spec_all_pid)
> +
> 	VIRTCHNL_ADD_PROTO_HDR_FIELD_BIT(hdr1,
> +						ETH, ETHERTYPE);
> +				else
> +
> 	VIRTCHNL_ADD_PROTO_HDR_FIELD_BIT(hdr,
> +						IPV4, PKID);
>  			}
> 
> +			rte_memcpy(hdr->buffer, &ipv4_spec->hdr,
> +				   sizeof(ipv4_spec->hdr));
> +
>  			hdrs.count = ++layer;
>  			break;
> 

I'm not familiar with IPv6 fragment rule. So not review that part.

<snip>
> --
> 2.20.1