Following the path through a bridge, there are 2 situations where the
action is to keep:

1. Packets have the encap, and keep the tag at ingress and keep it at
   egress. It is typical in the forward path, when a vlan-device and
   bridge are combined.

2. Packets do not have the encap, are tagged at ingress and untagged
   at egress. Can be found when only a bridge is in the forward path.
   It is also possible in the bridged path, that maybe added later.

For switchdev userports that support SWITCHDEV_OBJ_ID_PORT_VLAN in
sitaution 2, it is necessary to introduce DEV_PATH_BR_VLAN_KEEP_HW.
The typical situation 1 is unchanged: DEV_PATH_BR_VLAN_KEEP.

DEV_PATH_BR_VLAN_KEEP_HW is similar to DEV_PATH_BR_VLAN_TAG, with the
correcponding bit in ingress_vlans set.

Signed-off-by: Eric Woudstra <ericwouds@gmail.com>

---

Changes in v12:
 -Split from [PATCH v11 nf-next] netfilter: fastpath fixes

Changes in v11: (results of testing with bridge_fastpath.sh)
- Dropped "No ingress_vlan forward info for dsa user port" patch.
- Added Introduce DEV_PATH_BR_VLAN_KEEP_HW, which changed from
   applying only in the bridge-fastpath to all fastpaths. Added
   a better explanation to the description.

Changes in v10:
- Split from patch-set: bridge-fastpath and related improvements v9

 include/linux/netdevice.h          |  1 +
 net/bridge/br_device.c             |  1 +
 net/bridge/br_vlan.c               | 18 +++++++++++-------
 net/netfilter/nf_flow_table_path.c | 10 ++++++++++
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d4e6e00bb90a..8a0dba788703 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -907,6 +907,7 @@ struct net_device_path {
 				DEV_PATH_BR_VLAN_TAG,
 				DEV_PATH_BR_VLAN_UNTAG,
 				DEV_PATH_BR_VLAN_UNTAG_HW,
+				DEV_PATH_BR_VLAN_KEEP_HW,
 			}		vlan_mode;
 			u16		vlan_id;
 			__be16		vlan_proto;
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index a818fdc22da9..80b75c2e229b 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -423,6 +423,7 @@ static int br_fill_forward_path(struct net_device_path_ctx *ctx,
 	case DEV_PATH_BR_VLAN_UNTAG:
 		ctx->num_vlans--;
 		break;
+	case DEV_PATH_BR_VLAN_KEEP_HW:
 	case DEV_PATH_BR_VLAN_KEEP:
 		break;
 	}
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 636c86fa1183..a42bc75bc883 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1494,13 +1494,17 @@ int br_vlan_fill_forward_path_mode(struct net_bridge *br,
 	if (!(v->flags & BRIDGE_VLAN_INFO_UNTAGGED))
 		return 0;
 
-	if (path->bridge.vlan_mode == DEV_PATH_BR_VLAN_TAG)
-		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP;
-	else if (v->priv_flags & BR_VLFLAG_TAGGING_BY_SWITCHDEV)
-		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG_HW;
-	else
-		path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG;
-
+	if (path->bridge.vlan_mode == DEV_PATH_BR_VLAN_TAG) {
+		if (v->priv_flags & BR_VLFLAG_TAGGING_BY_SWITCHDEV)
+			path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP_HW;
+		else
+			path->bridge.vlan_mode = DEV_PATH_BR_VLAN_KEEP;
+	} else {
+		if (v->priv_flags & BR_VLFLAG_TAGGING_BY_SWITCHDEV)
+			path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG_HW;
+		else
+			path->bridge.vlan_mode = DEV_PATH_BR_VLAN_UNTAG;
+	}
 	return 0;
 }
 
diff --git a/net/netfilter/nf_flow_table_path.c b/net/netfilter/nf_flow_table_path.c
index f2d7822824bc..e8e4465263e2 100644
--- a/net/netfilter/nf_flow_table_path.c
+++ b/net/netfilter/nf_flow_table_path.c
@@ -154,6 +154,16 @@ static void nft_dev_path_info(const struct net_device_path_stack *stack,
 			case DEV_PATH_BR_VLAN_UNTAG_HW:
 				info->ingress_vlans |= BIT(info->num_encaps - 1);
 				break;
+			case DEV_PATH_BR_VLAN_KEEP_HW:
+				info->ingress_vlans |= BIT(info->num_encaps);
+				if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
+					info->indev = NULL;
+					break;
+				}
+				info->encap[info->num_encaps].id = path->bridge.vlan_id;
+				info->encap[info->num_encaps].proto = path->bridge.vlan_proto;
+				info->num_encaps++;
+				break;
 			case DEV_PATH_BR_VLAN_TAG:
 				if (info->num_encaps >= NF_FLOW_TABLE_ENCAP_MAX) {
 					info->indev = NULL;
-- 
2.53.0