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, 19 insertions, 4 deletions

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 8cae2daeb1cc..b529110c9355 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -169,6 +169,8 @@ void unregister_vlan_dev(struct net_device *dev)
 
         /* If the group is now empty, kill off the group. */
         if (grp->nr_vlans == 0) {
+                vlan_gvrp_uninit_applicant(real_dev);
+
                 if (real_dev->features & NETIF_F_HW_VLAN_RX)
                         real_dev->vlan_rx_register(real_dev, NULL);
 
@@ -249,15 +251,18 @@ int register_vlan_dev(struct net_device *dev)
                 ngrp = grp = vlan_group_alloc(real_dev);
                 if (!grp)
                         return -ENOBUFS;
+                err = vlan_gvrp_init_applicant(real_dev);
+                if (err < 0)
+                        goto out_free_group;
         }
 
         err = vlan_group_prealloc_vid(grp, vlan_id);
         if (err < 0)
-                goto out_free_group;
+                goto out_uninit_applicant;
 
         err = register_netdevice(dev);
         if (err < 0)
-                goto out_free_group;
+                goto out_uninit_applicant;
 
         /* Account for reference in struct vlan_dev_info */
         dev_hold(real_dev);
@@ -278,6 +283,9 @@ int register_vlan_dev(struct net_device *dev)
 
         return 0;
 
+out_uninit_applicant:
+        if (ngrp)
+                vlan_gvrp_uninit_applicant(real_dev);
 out_free_group:
         if (ngrp)
                 vlan_group_free(ngrp);
@@ -713,14 +721,20 @@ static int __init vlan_proto_init(void)
         if (err < 0)
                 goto err2;
 
-        err = vlan_netlink_init();
+        err = vlan_gvrp_init();
         if (err < 0)
                 goto err3;
 
+        err = vlan_netlink_init();
+        if (err < 0)
+                goto err4;
+
         dev_add_pack(&vlan_packet_type);
         vlan_ioctl_set(vlan_ioctl_handler);
         return 0;
 
+err4:
+        vlan_gvrp_uninit();
 err3:
         unregister_netdevice_notifier(&vlan_notifier_block);
 err2:
@@ -745,8 +759,9 @@ static void __exit vlan_cleanup_module(void)
                 BUG_ON(!hlist_empty(&vlan_group_hash[i]));
 
         unregister_pernet_gen_device(vlan_net_id, &vlan_net_ops);
-
         synchronize_net();
+
+        vlan_gvrp_uninit();
 }
 
 module_init(vlan_proto_init);