[PATCH v6 1/3] net: dsa: Add protocol support for 802.1AD when adding or deleting vlan for dsa switch port

[hongbo . wang]

From: "hongbo.wang" <hongbo.wang@xxxxxxx>

the following command will be supported:

Set bridge's vlan protocol:
    ip link set br0 type bridge vlan_protocol 802.1ad
Add VLAN:
    ip link add link swp1 name swp1.100 type vlan protocol 802.1ad id 100
Delete VLAN:
    ip link del link swp1 name swp1.100

Signed-off-by: hongbo.wang <hongbo.wang@xxxxxxx>
---
 include/net/switchdev.h |  1 +
 net/dsa/slave.c         | 51 +++++++++++++++++++++++++++++------------
 2 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 53e8b4994296..d93532201ec2 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -97,6 +97,7 @@ struct switchdev_obj_port_vlan {
 	u16 flags;
 	u16 vid_begin;
 	u16 vid_end;
+	u16 proto;
 };
 
 #define SWITCHDEV_OBJ_PORT_VLAN(OBJ) \
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 66a5268398a5..731ab9e2aacc 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -328,6 +328,7 @@ static int dsa_slave_vlan_add(struct net_device *dev,
 	 * it doesn't make sense to program a PVID, so clear this flag.
 	 */
 	vlan.flags &= ~BRIDGE_VLAN_INFO_PVID;
+	vlan.proto = ETH_P_8021Q;
 
 	err = dsa_port_vlan_add(dp->cpu_dp, &vlan, trans);
 	if (err)
@@ -1229,18 +1230,46 @@ static int dsa_slave_get_ts_info(struct net_device *dev,
 	return ds->ops->get_ts_info(ds, p->dp->index, ts);
 }
 
+static bool dsa_slave_skip_vlan_configuration(struct dsa_port *dp,
+					      u16 vlan_proto, u16 vid)
+{
+	struct bridge_vlan_info info;
+	bool change_proto = false;
+	u16 br_proto = 0;
+	int ret;
+
+	/* when changing bridge's vlan protocol, it will change bridge
+	 * port's protocol firstly, then set bridge's protocol. if it's
+	 * changing vlan protocol, should not return -EBUSY.
+	 */
+	ret = br_vlan_get_proto(dp->bridge_dev, &br_proto);
+	if (ret == 0 && br_proto != vlan_proto)
+		change_proto = true;
+
+	/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
+	 * device, respectively the VID is not found, returning
+	 * 0 means success, which is a failure for us here.
+	 */
+	ret = br_vlan_get_info(dp->bridge_dev, vid, &info);
+	if (ret == 0 && !change_proto)
+		return true;
+	else
+		return false;
+}
+
 static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
 				     u16 vid)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
+	u16 vlan_proto = ntohs(proto);
 	struct switchdev_obj_port_vlan vlan = {
 		.obj.id = SWITCHDEV_OBJ_ID_PORT_VLAN,
 		.vid_begin = vid,
 		.vid_end = vid,
 		/* This API only allows programming tagged, non-PVID VIDs */
 		.flags = 0,
+		.proto = vlan_proto,
 	};
-	struct bridge_vlan_info info;
 	struct switchdev_trans trans;
 	int ret;
 
@@ -1251,12 +1280,7 @@ static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
 		if (dsa_port_skip_vlan_configuration(dp))
 			return 0;
 
-		/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
-		 * device, respectively the VID is not found, returning
-		 * 0 means success, which is a failure for us here.
-		 */
-		ret = br_vlan_get_info(dp->bridge_dev, vid, &info);
-		if (ret == 0)
+		if (dsa_slave_skip_vlan_configuration(dp, vlan_proto, vid))
 			return -EBUSY;
 	}
 
@@ -1271,6 +1295,8 @@ static int dsa_slave_vlan_rx_add_vid(struct net_device *dev, __be16 proto,
 	if (ret)
 		return ret;
 
+	vlan.proto = ETH_P_8021Q;
+
 	/* And CPU port... */
 	trans.ph_prepare = true;
 	ret = dsa_port_vlan_add(dp->cpu_dp, &vlan, &trans);
@@ -1289,14 +1315,14 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
 				      u16 vid)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
+	u16 vlan_proto = ntohs(proto);
 	struct switchdev_obj_port_vlan vlan = {
 		.vid_begin = vid,
 		.vid_end = vid,
 		/* This API only allows programming tagged, non-PVID VIDs */
 		.flags = 0,
+		.proto = vlan_proto,
 	};
-	struct bridge_vlan_info info;
-	int ret;
 
 	/* Check for a possible bridge VLAN entry now since there is no
 	 * need to emulate the switchdev prepare + commit phase.
@@ -1305,12 +1331,7 @@ static int dsa_slave_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
 		if (dsa_port_skip_vlan_configuration(dp))
 			return 0;
 
-		/* br_vlan_get_info() returns -EINVAL or -ENOENT if the
-		 * device, respectively the VID is not found, returning
-		 * 0 means success, which is a failure for us here.
-		 */
-		ret = br_vlan_get_info(dp->bridge_dev, vid, &info);
-		if (ret == 0)
+		if (dsa_slave_skip_vlan_configuration(dp, vlan_proto, vid))
 			return -EBUSY;
 	}
 
-- 
2.17.1