4 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 40291f37502..a24916156f4 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1772,6 +1772,8 @@ extern void netif_carrier_on(struct net_device *dev);
 
 extern void netif_carrier_off(struct net_device *dev);
 
+extern void netif_notify_peers(struct net_device *dev);
+
 /**
  *      netif_dormant_on - mark device as dormant.
  *      @dev: network device
diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 540703b555c..22c2abb6197 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -210,6 +210,7 @@ static inline int notifier_to_errno(int ret)
 #define NETDEV_POST_INIT        0x0010
 #define NETDEV_UNREGISTER_BATCH 0x0011
 #define NETDEV_BONDING_DESLAVE  0x0012
+#define NETDEV_NOTIFY_PEERS     0x0012
 
 #define SYS_DOWN        0x0001  /* Notify of system down */
 #define SYS_RESTART     SYS_DOWN
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 382bc768ed5..da14c49284f 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1081,6 +1081,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
                 }
                 ip_mc_up(in_dev);
                 /* fall through */
+        case NETDEV_NOTIFY_PEERS:
         case NETDEV_CHANGEADDR:
                 /* Send gratuitous ARP to notify of link change */
                 if (IN_DEV_ARP_NOTIFY(in_dev)) {
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a63029ef3ed..bd1892fe4b2 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -327,6 +327,24 @@ void netif_carrier_off(struct net_device *dev)
 }
 EXPORT_SYMBOL(netif_carrier_off);
 
+/**
+ *      netif_notify_peers - notify network peers about existence of @dev
+ *      @dev: network device
+ *
+ * Generate traffic such that interested network peers are aware of
+ * @dev, such as by generating a gratuitous ARP. This may be used when
+ * a device wants to inform the rest of the network about some sort of
+ * reconfiguration such as a failover event or virtual machine
+ * migration.
+ */
+void netif_notify_peers(struct net_device *dev)
+{
+        rtnl_lock();
+        call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
+        rtnl_unlock();
+}
+EXPORT_SYMBOL(netif_notify_peers);
+
 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
    under all circumstances. It is difficult to invent anything faster or
    cheaper.