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

[Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>]

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);
+
 	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);
 }
 
-- 
2.11.0