Re: [PATCH nf-next] netfilter: flowtable: refresh flow if hardware offload fails

[wenxu <wenxu@xxxxxxxxx>]

在 2020/1/6 20:03, Pablo Neira Ayuso 写道:
> If nf_flow_offload_add() fails to add the flow to hardware, then the
> NF_FLOW_HW flag bit is unset and the flow remains in the flowtable
> software path.
>
> If flowtable hardware offload is enabled, this patch enqueues a new
> request to offload this flow to hardware.
>
> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
> ---
>   net/netfilter/nf_flow_table_core.c    |  4 +++-
>   net/netfilter/nf_flow_table_ip.c      | 10 ++++++++++
>   net/netfilter/nf_flow_table_offload.c |  3 +--
>   3 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
> index 9f134f44d139..388e87b06a00 100644
> --- a/net/netfilter/nf_flow_table_core.c
> +++ b/net/netfilter/nf_flow_table_core.c
> @@ -243,8 +243,10 @@ int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
>   		return err;
>   	}
>   
> -	if (flow_table->flags & NF_FLOWTABLE_HW_OFFLOAD)
> +	if (flow_table->flags & NF_FLOWTABLE_HW_OFFLOAD) {
> +		__set_bit(NF_FLOW_HW, &flow->flags);
>   		nf_flow_offload_add(flow_table, flow);
> +	}
>   
>   	return 0;
>   }
> diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
> index f4ccb5f5008b..6e0a5bacfe2e 100644
> --- a/net/netfilter/nf_flow_table_ip.c
> +++ b/net/netfilter/nf_flow_table_ip.c
> @@ -259,6 +259,11 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
>   
>   	dir = tuplehash->tuple.dir;
>   	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
> +
> +	if (unlikely((flow_table->flags & NF_FLOWTABLE_HW_OFFLOAD) &&
> +		     !test_and_set_bit(NF_FLOW_HW, &flow->flags)))
> +		nf_flow_offload_add(flow_table, flow);
> +

Maybe put the refresh operation ather the nf_flow_state_check to aviod

the RST/FIN packets do the this?

>   	rt = (struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
>   	outdev = rt->dst.dev;
>   
> @@ -488,6 +493,11 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
>   
>   	dir = tuplehash->tuple.dir;
>   	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
> +
> +	if (unlikely((flow_table->flags & NF_FLOWTABLE_HW_OFFLOAD) &&
> +		     !test_and_set_bit(NF_FLOW_HW, &flow->flags)))
> +		nf_flow_offload_add(flow_table, flow);
> +
>   	rt = (struct rt6_info *)flow->tuplehash[dir].tuple.dst_cache;
>   	outdev = rt->dst.dev;
>   
> diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c
> index 8a1fe391666e..e7b766b3f731 100644
> --- a/net/netfilter/nf_flow_table_offload.c
> +++ b/net/netfilter/nf_flow_table_offload.c
> @@ -723,7 +723,7 @@ static void flow_offload_work_handler(struct work_struct *work)
>   		case FLOW_CLS_REPLACE:
>   			ret = flow_offload_work_add(offload);
>   			if (ret < 0)
> -				__clear_bit(NF_FLOW_HW, &offload->flow->flags);
> +				clear_bit(NF_FLOW_HW, &offload->flow->flags);
>   			break;
>   		case FLOW_CLS_DESTROY:
>   			flow_offload_work_del(offload);
> @@ -776,7 +776,6 @@ void nf_flow_offload_add(struct nf_flowtable *flowtable,
>   	if (!offload)
>   		return;
>   
> -	__set_bit(NF_FLOW_HW, &flow->flags);
>   	flow_offload_queue_work(offload);
>   }
>