[BRIDGE]: netlink interface for link management

Add basic netlink support to the Ethernet bridge. Including:
 * dump interfaces in bridges
 * monitor link status changes
 * change state of bridge port

For some demo programs see:
	http://developer.osdl.org/shemminger/prototypes/brnl.tar.gz

These are to allow building a daemon that does alternative
implementations of Spanning Tree Protocol.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 23dea14..14cd025 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/smp_lock.h>
 #include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
 
 #include "br_private.h"
 #include "br_private_stp.h"
@@ -86,6 +87,7 @@
 void br_stp_enable_port(struct net_bridge_port *p)
 {
 	br_init_port(p);
+	br_ifinfo_notify(RTM_NEWLINK, p);
 	br_port_state_selection(p->br);
 }
 
@@ -99,6 +101,8 @@
 	printk(KERN_INFO "%s: port %i(%s) entering %s state\n",
 	       br->dev->name, p->port_no, p->dev->name, "disabled");
 
+	br_ifinfo_notify(RTM_DELLINK, p);
+
 	wasroot = br_is_root_bridge(br);
 	br_become_designated_port(p);
 	p->state = BR_STATE_DISABLED;