mt7621: TCP and UDP traffic is forwarded correctly by HWNAT (1% CPU usage)

target/linux/generic/pending-4.14/647-netfilter-nf_flow_table_hw-fix-incorrect-ethernet-ds.patch

+From: Konstantin Vasin <tempest921@gmail.com>
+Date: Mon, 9 Mar 2020 18:38:54 +0300
+Subject: [PATCH] netfilter: nf_flow_table_hw: fix incorrect ethernet dst
+ address
+
+Ethernet destination for original traffic takes the source ethernet
+address in the reply direction. For reply traffic, this takes
+the source ethernet address of the original destination.
+
+This fix is based on the upstream commit 1b67e506:
+("netfilter: nf_flow_table_offload: fix incorrect ethernet dst address")
+from wenxu <wenxu@ucloud.cn>
+
+Signed-off-by: Konstantin Vasin <tempest921@gmail.com>
+---
+
+--- a/net/netfilter/nf_flow_table_hw.c
++++ b/net/netfilter/nf_flow_table_hw.c
+@@ -24,17 +24,23 @@ struct flow_offload_hw {
+ 	struct flow_offload_hw_path dest;
+ };
+ 
+-static void flow_offload_check_ethernet(struct flow_offload_tuple *tuple,
++static void flow_offload_check_ethernet(struct flow_offload *flow,
++					enum flow_offload_tuple_dir dir,
+ 					struct flow_offload_hw_path *path)
+ {
+ 	struct net_device *dev = path->dev;
+ 	struct neighbour *n;
++	const void *daddr;
++	const struct dst_entry *dst_cache;
+ 
+ 	if (dev->type != ARPHRD_ETHER)
+ 		return;
+ 
+ 	memcpy(path->eth_src, path->dev->dev_addr, ETH_ALEN);
+-	n = dst_neigh_lookup(tuple->dst_cache, &tuple->src_v4);
++
++	daddr = &flow->tuplehash[dir].tuple.src_v4;
++	dst_cache = flow->tuplehash[!dir].tuple.dst_cache;
++	n = dst_neigh_lookup(dst_cache, daddr);
+ 	if (!n)
+ 		return;
+ 
+@@ -44,17 +50,18 @@ static void flow_offload_check_ethernet(struct flow_offload_tuple *tuple,
+ }
+ 
+ static int flow_offload_check_path(struct net *net,
+-				   struct flow_offload_tuple *tuple,
++				   struct flow_offload *flow,
++				   enum flow_offload_tuple_dir dir,
+ 				   struct flow_offload_hw_path *path)
+ {
+ 	struct net_device *dev;
+ 
+-	dev = dev_get_by_index_rcu(net, tuple->iifidx);
++	dev = dev_get_by_index_rcu(net, flow->tuplehash[dir].tuple.iifidx);
+ 	if (!dev)
+ 		return -ENOENT;
+ 
+ 	path->dev = dev;
+-	flow_offload_check_ethernet(tuple, path);
++	flow_offload_check_ethernet(flow, dir, path);
+ 
+ 	if (dev->netdev_ops->ndo_flow_offload_check)
+ 		return dev->netdev_ops->ndo_flow_offload_check(path);
+@@ -133,17 +140,14 @@ flow_offload_hw_prepare(struct net *net, struct flow_offload *flow)
+ {
+ 	struct flow_offload_hw_path src = {};
+ 	struct flow_offload_hw_path dest = {};
+-	struct flow_offload_tuple *tuple;
+ 	struct flow_offload_hw *offload = NULL;
+ 
+ 	rcu_read_lock_bh();
+ 
+-	tuple = &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple;
+-	if (flow_offload_check_path(net, tuple, &src))
++	if (flow_offload_check_path(net, flow, FLOW_OFFLOAD_DIR_ORIGINAL, &src))
+ 		goto out;
+ 
+-	tuple = &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple;
+-	if (flow_offload_check_path(net, tuple, &dest))
++	if (flow_offload_check_path(net, flow, FLOW_OFFLOAD_DIR_REPLY, &dest))
+ 		goto out;
+ 
+ 	if (!src.dev->netdev_ops->ndo_flow_offload)
+

target/linux/generic/pending-4.14/648-netfilter-nf_flow_table_hw-check-the-status-of-dst_n.patch

+From: Konstantin Vasin <tempest921@gmail.com>
+Date: Mon, 9 Mar 2020 17:41:22 +0300
+Subject: [PATCH] netfilter: nf_flow_table_hw: check the status of
+ dst_neigh
+
+It's better to check the nud_state is VALID.
+If there is not neigh previos, the lookup will
+create a non NUD_VALID with 00:00:00:00:00:00 mac.
+
+This fix is based on the upstream commit f31ad71c44
+("netfilter: nf_flow_table_offload: check the status of dst_neigh")
+from wenxu <wenxu@ucloud.cn>
+
+Signed-off-by: Konstantin Vasin <tempest921@gmail.com>
+---
+
+index e831c8830e91..1238d675a316 100644
+--- a/net/netfilter/nf_flow_table_hw.c
++++ b/net/netfilter/nf_flow_table_hw.c
+@@ -44,8 +44,10 @@ static void flow_offload_check_ethernet(struct flow_offload *flow,
+ 	if (!n)
+ 		return;
+ 
+-	memcpy(path->eth_dest, n->ha, ETH_ALEN);
+-	path->flags |= FLOW_OFFLOAD_PATH_ETHERNET;
++	if (n->nud_state & NUD_VALID) {
++		memcpy(path->eth_dest, n->ha, ETH_ALEN);
++		path->flags |= FLOW_OFFLOAD_PATH_ETHERNET;
++	}
+ 	neigh_release(n);
+ }
+