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>

4 files changed, 50 insertions, 17 deletions

diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
index 3ca9817ca7e8..c6c30e28f396 100644
--- a/include/uapi/linux/if_bridge.h
+++ b/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;
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index fe1980d5a7e4..e044cc0b5650 100644
--- a/net/bridge/br_netlink.c
+++ b/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;
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index ea8e7efd9137..1ae6395a0369 100644
--- a/net/bridge/br_private.h
+++ b/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;
 }
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 20057de56db0..c79940cff3a1 100644
--- a/net/bridge/br_vlan.c
+++ b/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,
 }