vlan: Add GVRP support

Add GVRP support for dynamically registering VLANs with switches.

By default GVRP is disabled because we only support the applicant-only
participant model, which means it should not be enabled on vlans that
are members of a bridge. Since there is currently no way to cleanly
determine that, the user is responsible for enabling it.

The code is pretty small and low impact, its wrapped in a config
option though because it depends on the GARP implementation and
the STP core.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 2 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 76c665cdab66..a0617bf7cec6 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -512,10 +512,17 @@ int vlan_dev_change_flags(const struct net_device *dev, u32 flags, u32 mask)
         struct vlan_dev_info *vlan = vlan_dev_info(dev);
         u32 old_flags = vlan->flags;
 
-        if (mask & ~VLAN_FLAG_REORDER_HDR)
+        if (mask & ~(VLAN_FLAG_REORDER_HDR | VLAN_FLAG_GVRP))
                 return -EINVAL;
 
         vlan->flags = (old_flags & ~mask) | (flags & mask);
+
+        if (netif_running(dev) && (vlan->flags ^ old_flags) & VLAN_FLAG_GVRP) {
+                if (vlan->flags & VLAN_FLAG_GVRP)
+                        vlan_gvrp_request_join(dev);
+                else
+                        vlan_gvrp_request_leave(dev);
+        }
         return 0;
 }
 
@@ -550,12 +557,19 @@ static int vlan_dev_open(struct net_device *dev)
         if (dev->flags & IFF_PROMISC)
                 dev_set_promiscuity(real_dev, 1);
 
+        if (vlan->flags & VLAN_FLAG_GVRP)
+                vlan_gvrp_request_join(dev);
+
         return 0;
 }
 
 static int vlan_dev_stop(struct net_device *dev)
 {
-        struct net_device *real_dev = vlan_dev_info(dev)->real_dev;
+        struct vlan_dev_info *vlan = vlan_dev_info(dev);
+        struct net_device *real_dev = vlan->real_dev;
+
+        if (vlan->flags & VLAN_FLAG_GVRP)
+                vlan_gvrp_request_leave(dev);
 
         dev_mc_unsync(real_dev, dev);
         dev_unicast_unsync(real_dev, dev);