netfilter: flowtable: refresh timeout after dst and writable checks

Refresh the timeout (and retry hardware offload) once the skbuff dst
is confirmed to be current and after the skbuff is made writable.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_flow_table_ip.c

@@ -246,8 +246,6 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	if (nf_flow_state_check(flow, iph->protocol, skb, thoff))
 		return NF_ACCEPT;
 
-	flow_offload_refresh(flow_table, flow);
-
 	if (!dst_check(&rt->dst, 0)) {
 		flow_offload_teardown(flow);
 		return NF_ACCEPT;
@@ -256,6 +254,8 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb,
 	if (skb_try_make_writable(skb, thoff + hdrsize))
 		return NF_DROP;
 
+	flow_offload_refresh(flow_table, flow);
+
 	iph = ip_hdr(skb);
 	nf_flow_nat_ip(flow, skb, thoff, dir, iph);
 
@@ -466,8 +466,6 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 				sizeof(*ip6h)))
 		return NF_ACCEPT;
 
-	flow_offload_refresh(flow_table, flow);
-
 	if (!dst_check(&rt->dst, 0)) {
 		flow_offload_teardown(flow);
 		return NF_ACCEPT;
@@ -476,6 +474,8 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb,
 	if (skb_try_make_writable(skb, sizeof(*ip6h) + hdrsize))
 		return NF_DROP;
 
+	flow_offload_refresh(flow_table, flow);
+
 	ip6h = ipv6_hdr(skb);
 	nf_flow_nat_ipv6(flow, skb, dir, ip6h);