Re: [dpdk-stable] [PATCH] ethdev: fix RSS flow expansion in case of mismatch

[Dekel Peled <dekelp@mellanox.com>]

Resending To: maintaners.

> -----Original Message-----
> From: Dekel Peled <dekelp@mellanox.com>
> Sent: Monday, July 27, 2020 3:58 PM
> To: Matan Azrad <matan@mellanox.com>; Slava Ovsiienko
> <viacheslavo@mellanox.com>; Raslan Darawsheh <rasland@mellanox.com>
> Cc: dev@dpdk.org; stable@dpdk.org
> Subject: [PATCH] ethdev: fix RSS flow expansion in case of mismatch
> 
> Function rte_flow_expand_rss() is used to expand a flow rule with partial
> pattern into several rules, to ensure all relevant packets are matched.
> It uses utility function rte_flow_expand_rss_item_complete(), to check if
> the last valid item in the flow rule pattern needs to be completed.
> For example the pattern "eth / ipv4 proto is 17 / end" will be completed with
> a "udp" item.
> This function returns "void" item in two cases:
> 1) The last item has empty spec, for example "eth / ipv4 / end".
> 2) The last itme has spec that can't be expanded for RSS.
>    For example the pattern "eth / ipv4 proto is 47 / end" ends with IPv4
>    item that has next protocol GRE.
> 
> In both cases the flow rule may be expanded, but in the second case such
> expansion may create rules with invalid pattern.
> For example "eth / ipv4 proto is 47 / udp / end".
> In such a case the flow rule should not be expanded.
> 
> This patch updates function rte_flow_expand_rss_item_complete().
> Return value RTE_FLOW_ITEM_TYPE_END is used to indicate the flow rule
> should not be expanded.
> In such a case, rte_flow_expand_rss() will return with the original flow rule
> only, without any expansion.
> 
> Fixes: fc2dd8dd492f ("ethdev: fix expand RSS flows")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Dekel Peled <dekelp@mellanox.com>
> Acked-by: Xiaoyu Min <jackmin@mellanox.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---
>  lib/librte_ethdev/rte_flow.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c index
> f8fdd68..59a386d 100644
> --- a/lib/librte_ethdev/rte_flow.c
> +++ b/lib/librte_ethdev/rte_flow.c
> @@ -247,6 +247,8 @@ struct rte_flow_desc_data {
>  			ret = RTE_FLOW_ITEM_TYPE_IPV6;
>  		else if (rte_be_to_cpu_16(ether_type) ==
> RTE_ETHER_TYPE_VLAN)
>  			ret = RTE_FLOW_ITEM_TYPE_VLAN;
> +		else
> +			ret = RTE_FLOW_ITEM_TYPE_END;
>  		break;
>  	case RTE_FLOW_ITEM_TYPE_VLAN:
>  		if (item->mask)
> @@ -264,6 +266,8 @@ struct rte_flow_desc_data {
>  			ret = RTE_FLOW_ITEM_TYPE_IPV6;
>  		else if (rte_be_to_cpu_16(ether_type) ==
> RTE_ETHER_TYPE_VLAN)
>  			ret = RTE_FLOW_ITEM_TYPE_VLAN;
> +		else
> +			ret = RTE_FLOW_ITEM_TYPE_END;
>  		break;
>  	case RTE_FLOW_ITEM_TYPE_IPV4:
>  		if (item->mask)
> @@ -284,6 +288,8 @@ struct rte_flow_desc_data {
>  			ret = RTE_FLOW_ITEM_TYPE_IPV4;
>  		else if (ip_next_proto == IPPROTO_IPV6)
>  			ret = RTE_FLOW_ITEM_TYPE_IPV6;
> +		else
> +			ret = RTE_FLOW_ITEM_TYPE_END;
>  		break;
>  	case RTE_FLOW_ITEM_TYPE_IPV6:
>  		if (item->mask)
> @@ -304,6 +310,8 @@ struct rte_flow_desc_data {
>  			ret = RTE_FLOW_ITEM_TYPE_IPV4;
>  		else if (ip_next_proto == IPPROTO_IPV6)
>  			ret = RTE_FLOW_ITEM_TYPE_IPV6;
> +		else
> +			ret = RTE_FLOW_ITEM_TYPE_END;
>  		break;
>  	default:
>  		ret = RTE_FLOW_ITEM_TYPE_VOID;
> @@ -1110,10 +1118,14 @@ enum rte_flow_conv_item_spec_type {
>  	memset(flow_items, 0, sizeof(flow_items));
>  	user_pattern_size -= sizeof(*item);
>  	/*
> -	 * Check if the last valid item has spec set
> -	 * and need complete pattern.
> +	 * Check if the last valid item has spec set, need complete pattern,
> +	 * and the pattern can be used for expansion.
>  	 */
>  	missed_item.type =
> rte_flow_expand_rss_item_complete(last_item);
> +	if (missed_item.type == RTE_FLOW_ITEM_TYPE_END) {
> +		/* Item type END indicates expansion is not required. */
> +		return lsize;
> +	}
>  	if (missed_item.type != RTE_FLOW_ITEM_TYPE_VOID) {
>  		next = NULL;
>  		missed = 1;
> --
> 1.8.3.1