bridge: add NTF_USE support

More changes to the recent code to support control of forwarding
database via netlink.
   * Support NTF_USE like neighbour table
   * Validate state bits from application
   * Only send notifications (and change bits) if new entry is
     different.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 11 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index c8e7861b88b0..973813e34428 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -556,7 +556,7 @@ skip:
         return skb->len;
 }
 
-/* Create new static fdb entry */
+/* Update (create or replace) forwarding database entry */
 static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
                          __u16 state, __u16 flags)
 {
@@ -575,16 +575,21 @@ static int fdb_add_entry(struct net_bridge_port *source, const __u8 *addr,
         } else {
                 if (flags & NLM_F_EXCL)
                         return -EEXIST;
+        }
+
+        if (fdb_to_nud(fdb) != state) {
+                if (state & NUD_PERMANENT)
+                        fdb->is_local = fdb->is_static = 1;
+                else if (state & NUD_NOARP) {
+                        fdb->is_local = 0;
+                        fdb->is_static = 1;
+                } else
+                        fdb->is_local = fdb->is_static = 0;
 
-                if (flags & NLM_F_REPLACE)
-                        fdb->updated = fdb->used = jiffies;
-                fdb->is_local = fdb->is_static = 0;
+                fdb->updated = fdb->used = jiffies;
+                fdb_notify(fdb, RTM_NEWNEIGH);
         }
 
-        if (state & NUD_PERMANENT)
-                fdb->is_local = fdb->is_static = 1;
-        else if (state & NUD_NOARP)
-                fdb->is_static = 1;
         return 0;
 }
 
@@ -627,6 +632,11 @@ int br_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                 return -EINVAL;
         }
 
+        if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
+                pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
+                return -EINVAL;
+        }
+
         p = br_port_get_rtnl(dev);
         if (p == NULL) {
                 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
@@ -634,9 +644,15 @@ int br_fdb_add(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
                 return -EINVAL;
         }
 
-        spin_lock_bh(&p->br->hash_lock);
-        err = fdb_add_entry(p, addr, ndm->ndm_state, nlh->nlmsg_flags);
-        spin_unlock_bh(&p->br->hash_lock);
+        if (ndm->ndm_flags & NTF_USE) {
+                rcu_read_lock();
+                br_fdb_update(p->br, p, addr);
+                rcu_read_unlock();
+        } else {
+                spin_lock_bh(&p->br->hash_lock);
+                err = fdb_add_entry(p, addr, ndm->ndm_state, nlh->nlmsg_flags);
+                spin_unlock_bh(&p->br->hash_lock);
+        }
 
         return err;
 }