bridge: Add the ability to configure pvid

A user may designate a certain vlan as PVID.  This means that
any ingress frame that does not contain a vlan tag is assigned to
this vlan and any forwarding decisions are made with this vlan in mind.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/if_bridge.h

@@ -120,6 +120,7 @@ enum {
 #define IFLA_BRIDGE_MAX (__IFLA_BRIDGE_MAX - 1)
 
 #define BRIDGE_VLAN_INFO_MASTER	(1<<0)	/* Operate on Bridge device as well */
+#define BRIDGE_VLAN_INFO_PVID	(1<<1)	/* VLAN is PVID, ingress untagged */
 
 struct bridge_vlan_info {
 	u16 flags;

net/bridge/br_netlink.c

@@ -120,6 +120,7 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 		const struct net_port_vlans *pv;
 		struct bridge_vlan_info vinfo;
 		u16 vid;
+		u16 pvid;
 
 		if (port)
 			pv = nbp_get_vlan_info(port);
@@ -133,12 +134,15 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 		if (!af)
 			goto nla_put_failure;
 
+		pvid = br_get_pvid(pv);
 		for (vid = find_first_bit(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN);
 		     vid < BR_VLAN_BITMAP_LEN;
 		     vid = find_next_bit(pv->vlan_bitmap,
 					 BR_VLAN_BITMAP_LEN, vid+1)) {
 			vinfo.vid = vid;
 			vinfo.flags = 0;
+			if (vid == pvid)
+				vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
 			if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
 				    sizeof(vinfo), &vinfo))
 				goto nla_put_failure;
@@ -239,14 +243,15 @@ static int br_afspec(struct net_bridge *br,
 		switch (cmd) {
 		case RTM_SETLINK:
 			if (p) {
-				err = nbp_vlan_add(p, vinfo->vid);
+				err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
 				if (err)
 					break;
 
 				if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
-					err = br_vlan_add(p->br, vinfo->vid);
+					err = br_vlan_add(p->br, vinfo->vid,
+							  vinfo->flags);
 			} else
-				err = br_vlan_add(br, vinfo->vid);
+				err = br_vlan_add(br, vinfo->vid, vinfo->flags);
 
 			if (err)
 				break;

net/bridge/br_private.h

@@ -562,11 +562,11 @@ extern bool br_allowed_egress(struct net_bridge *br,
 extern struct sk_buff *br_handle_vlan(struct net_bridge *br,
 				      const struct net_port_vlans *v,
 				      struct sk_buff *skb);
-extern int br_vlan_add(struct net_bridge *br, u16 vid);
+extern int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags);
 extern int br_vlan_delete(struct net_bridge *br, u16 vid);
 extern void br_vlan_flush(struct net_bridge *br);
 extern int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
-extern int nbp_vlan_add(struct net_bridge_port *port, u16 vid);
+extern int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags);
 extern int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
 extern void nbp_vlan_flush(struct net_bridge_port *port);
 
@@ -633,7 +633,7 @@ static inline struct sk_buff *br_handle_vlan(struct net_bridge *br,
 	return skb;
 }
 
-static inline int br_vlan_add(struct net_bridge *br, u16 vid)
+static inline int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 {
 	return -EOPNOTSUPP;
 }
@@ -647,7 +647,7 @@ static inline void br_vlan_flush(struct net_bridge *br)
 {
 }
 
-static inline int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
+static inline int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 {
 	return -EOPNOTSUPP;
 }

net/bridge/br_vlan.c

@@ -5,12 +5,33 @@
 
 #include "br_private.h"
 
-static int __vlan_add(struct net_port_vlans *v, u16 vid)
+static void __vlan_add_pvid(struct net_port_vlans *v, u16 vid)
+{
+	if (v->pvid == vid)
+		return;
+
+	smp_wmb();
+	v->pvid = vid;
+}
+
+static void __vlan_delete_pvid(struct net_port_vlans *v, u16 vid)
+{
+	if (v->pvid != vid)
+		return;
+
+	smp_wmb();
+	v->pvid = 0;
+}
+
+static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
 {
 	int err;
 
-	if (test_bit(vid, v->vlan_bitmap))
-		return -EEXIST;
+	if (test_bit(vid, v->vlan_bitmap)) {
+		if (flags & BRIDGE_VLAN_INFO_PVID)
+			__vlan_add_pvid(v, vid);
+		return 0;
+	}
 
 	if (v->port_idx && vid) {
 		struct net_device *dev = v->parent.port->dev;
@@ -29,6 +50,9 @@ static int __vlan_add(struct net_port_vlans *v, u16 vid)
 
 	set_bit(vid, v->vlan_bitmap);
 	v->num_vlans++;
+	if (flags & BRIDGE_VLAN_INFO_PVID)
+		__vlan_add_pvid(v, vid);
+
 	return 0;
 }
 
@@ -37,6 +61,8 @@ static int __vlan_del(struct net_port_vlans *v, u16 vid)
 	if (!test_bit(vid, v->vlan_bitmap))
 		return -EINVAL;
 
+	__vlan_delete_pvid(v, vid);
+
 	if (v->port_idx && vid) {
 		struct net_device *dev = v->parent.port->dev;
 
@@ -58,6 +84,8 @@ static int __vlan_del(struct net_port_vlans *v, u16 vid)
 
 static void __vlan_flush(struct net_port_vlans *v)
 {
+	smp_wmb();
+	v->pvid = 0;
 	bitmap_zero(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
 	if (v->port_idx)
 		rcu_assign_pointer(v->parent.port->vlan_info, NULL);
@@ -185,7 +213,7 @@ bool br_allowed_egress(struct net_bridge *br,
 }
 
 /* Must be protected by RTNL */
-int br_vlan_add(struct net_bridge *br, u16 vid)
+int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 {
 	struct net_port_vlans *pv = NULL;
 	int err;
@@ -194,7 +222,7 @@ int br_vlan_add(struct net_bridge *br, u16 vid)
 
 	pv = rtnl_dereference(br->vlan_info);
 	if (pv)
-		return __vlan_add(pv, vid);
+		return __vlan_add(pv, vid, flags);
 
 	/* Create port vlan infomration
 	 */
@@ -203,7 +231,7 @@ int br_vlan_add(struct net_bridge *br, u16 vid)
 		return -ENOMEM;
 
 	pv->parent.br = br;
-	err = __vlan_add(pv, vid);
+	err = __vlan_add(pv, vid, flags);
 	if (err)
 		goto out;
 
@@ -234,7 +262,6 @@ void br_vlan_flush(struct net_bridge *br)
 	struct net_port_vlans *pv;
 
 	ASSERT_RTNL();
-
 	pv = rtnl_dereference(br->vlan_info);
 	if (!pv)
 		return;
@@ -258,7 +285,7 @@ unlock:
 }
 
 /* Must be protected by RTNL */
-int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
+int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 {
 	struct net_port_vlans *pv = NULL;
 	int err;
@@ -267,7 +294,7 @@ int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
 
 	pv = rtnl_dereference(port->vlan_info);
 	if (pv)
-		return __vlan_add(pv, vid);
+		return __vlan_add(pv, vid, flags);
 
 	/* Create port vlan infomration
 	 */
@@ -279,7 +306,7 @@ int nbp_vlan_add(struct net_bridge_port *port, u16 vid)
 
 	pv->port_idx = port->port_no;
 	pv->parent.port = port;
-	err = __vlan_add(pv, vid);
+	err = __vlan_add(pv, vid, flags);
 	if (err)
 		goto clean_up;