net: convert resend IGMP to notifier event

Until now, bond_resend_igmp_join_requests() looks for vlans attached to
bonding device, bridge where bonding act as port manually. It does not
care of other scenarios, like stacked bonds or team device above. Make
this more generic and use netdev notifier to propagate the event to
upper devices and to actually call ip_mc_rejoin_groups().

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 40 insertions, 6 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index cd71190d2962..375aca372250 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1323,16 +1323,17 @@ out:
 EXPORT_SYMBOL(ip_mc_inc_group);
 
 /*
- *	Resend IGMP JOIN report; used for bonding.
- *	Called with rcu_read_lock()
+ *	Resend IGMP JOIN report; used by netdev notifier.
  */
-void ip_mc_rejoin_groups(struct in_device *in_dev)
+static void ip_mc_rejoin_groups(struct in_device *in_dev)
 {
 #ifdef CONFIG_IP_MULTICAST
 	struct ip_mc_list *im;
 	int type;
 
-	for_each_pmc_rcu(in_dev, im) {
+	ASSERT_RTNL();
+
+	for_each_pmc_rtnl(in_dev, im) {
 		if (im->multiaddr == IGMP_ALL_HOSTS)
 			continue;
 
@@ -1349,7 +1350,6 @@ void ip_mc_rejoin_groups(struct in_device *in_dev)
 	}
 #endif
 }
-EXPORT_SYMBOL(ip_mc_rejoin_groups);
 
 /*
  *	A socket has left a multicast group on device dev
@@ -2735,8 +2735,42 @@ static struct pernet_operations igmp_net_ops = {
 	.exit = igmp_net_exit,
 };
 
+static int igmp_netdev_event(struct notifier_block *this,
+			     unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct in_device *in_dev;
+
+	switch (event) {
+	case NETDEV_RESEND_IGMP:
+		in_dev = __in_dev_get_rtnl(dev);
+		if (in_dev)
+			ip_mc_rejoin_groups(in_dev);
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block igmp_notifier = {
+	.notifier_call = igmp_netdev_event,
+};
+
 int __init igmp_mc_proc_init(void)
 {
-	return register_pernet_subsys(&igmp_net_ops);
+	int err;
+
+	err = register_pernet_subsys(&igmp_net_ops);
+	if (err)
+		return err;
+	err = register_netdevice_notifier(&igmp_notifier);
+	if (err)
+		goto reg_notif_fail;
+	return 0;
+
+reg_notif_fail:
+	unregister_pernet_subsys(&igmp_net_ops);
+	return err;
 }
 #endif