zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/net/bridge/br_notify.c b/ap/os/linux/linux-3.4.x/net/bridge/br_notify.c
new file mode 100644
index 0000000..a76b621
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/net/bridge/br_notify.c
@@ -0,0 +1,113 @@
+/*
+ * Device event handling
+ * Linux ethernet bridge
+ *
+ * Authors:
+ * Lennert Buytenhek <buytenh@gnu.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/rtnetlink.h>
+#include <net/net_namespace.h>
+
+#include "br_private.h"
+
+static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr);
+
+struct notifier_block br_device_notifier = {
+ .notifier_call = br_device_event
+};
+
+/*
+ * Handle changes in state of network devices enslaved to a bridge.
+ *
+ * Note: don't care about up/down if bridge itself is down, because
+ * port state is checked when bridge is brought up.
+ */
+static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct net_bridge_port *p;
+ struct net_bridge *br;
+ bool changed_addr;
+ int err;
+
+ /* register of bridge completed, add sysfs entries */
+ if ((dev->priv_flags & IFF_EBRIDGE) && event == NETDEV_REGISTER) {
+ br_sysfs_addbr(dev);
+ return NOTIFY_DONE;
+ }
+
+ /* not a port of a bridge */
+ p = br_port_get_rtnl(dev);
+ if (!p)
+ return NOTIFY_DONE;
+
+ br = p->br;
+
+ switch (event) {
+ case NETDEV_CHANGEMTU:
+ dev_set_mtu(br->dev, br_min_mtu(br));
+ break;
+
+ case NETDEV_CHANGEADDR:
+ spin_lock_bh(&br->lock);
+ br_fdb_changeaddr(p, dev->dev_addr);
+ changed_addr = br_stp_recalculate_bridge_id(br);
+ spin_unlock_bh(&br->lock);
+
+ if (changed_addr)
+ call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
+
+ break;
+
+ case NETDEV_CHANGE:
+ br_port_carrier_check(p);
+ break;
+
+ case NETDEV_FEAT_CHANGE:
+ netdev_update_features(br->dev);
+ break;
+
+ case NETDEV_DOWN:
+ spin_lock_bh(&br->lock);
+ if (br->dev->flags & IFF_UP)
+ br_stp_disable_port(p);
+ spin_unlock_bh(&br->lock);
+ break;
+
+ case NETDEV_UP:
+ if (netif_carrier_ok(dev) && (br->dev->flags & IFF_UP)) {
+ spin_lock_bh(&br->lock);
+ br_stp_enable_port(p);
+ spin_unlock_bh(&br->lock);
+ }
+ break;
+
+ case NETDEV_UNREGISTER:
+ br_del_if(br, dev);
+ break;
+
+ case NETDEV_CHANGENAME:
+ err = br_sysfs_renameif(p);
+ if (err)
+ return notifier_from_errno(err);
+ break;
+
+ case NETDEV_PRE_TYPE_CHANGE:
+ /* Forbid underlaying device to change its type. */
+ return NOTIFY_BAD;
+ }
+
+ /* Events that may cause spanning tree to refresh */
+ if (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
+ event == NETDEV_CHANGE || event == NETDEV_DOWN)
+ br_ifinfo_notify(RTM_NEWLINK, p);
+
+ return NOTIFY_DONE;
+}