[PATCH v11 nf-next 3/3] bridge: Introduce DEV_PATH_BR_VLAN_KEEP_HW

[Eric Woudstra]

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.

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 at gmail.com>
---
 include/linux/netdevice.h        |  1 +
 net/bridge/br_device.c           |  1 +
 net/bridge/br_vlan.c             | 18 +++++++++++-------
 net/netfilter/nft_flow_offload.c |  3 +++
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index cf3b6445817b..4e8eaae8c441 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -887,6 +887,7 @@ 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 6bfc7da10865..0f714df92118 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -1490,13 +1490,17 @@ 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/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index d84e677384da..fdf927a8252d 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -145,6 +145,9 @@ 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);
+				fallthrough;
 			case DEV_PATH_BR_VLAN_TAG:
 				info->encap[info->num_encaps].id = path->bridge.vlan_id;
 				info->encap[info->num_encaps].proto = path->bridge.vlan_proto;
-- 
2.47.1