bonding: add retransmit membership reports tunable

Allow sysadmins to configure the number of multicast
membership report sent on a link failure event.

Signed-off-by: Flavio Leitner <fleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index ad63866..6f5e6b4 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -109,6 +109,7 @@
 static char *fail_over_mac;
 static int all_slaves_active = 0;
 static struct bond_params bonding_defaults;
+static int resend_igmp = BOND_DEFAULT_RESEND_IGMP;
 
 module_param(max_bonds, int, 0);
 MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
@@ -163,6 +164,8 @@
 MODULE_PARM_DESC(all_slaves_active, "Keep all frames received on an interface"
 				     "by setting active flag for all slaves.  "
 				     "0 for never (default), 1 for always.");
+module_param(resend_igmp, int, 0);
+MODULE_PARM_DESC(resend_igmp, "Number of IGMP membership reports to send on link failure");
 
 /*----------------------------- Global variables ----------------------------*/
 
@@ -905,6 +908,9 @@
 		}
 	}
 
+	if (--bond->igmp_retrans > 0)
+		queue_delayed_work(bond->wq, &bond->mcast_work, HZ/5);
+
 	read_unlock(&bond->lock);
 }
 
@@ -1213,6 +1219,7 @@
 	 * all were sent on curr_active_slave */
 	if ((USES_PRIMARY(bond->params.mode) && new_active) ||
 	    bond->params.mode == BOND_MODE_ROUNDROBIN) {
+		bond->igmp_retrans = bond->params.resend_igmp;
 		queue_delayed_work(bond->wq, &bond->mcast_work, 0);
 	}
 }
@@ -4933,6 +4940,13 @@
 		all_slaves_active = 0;
 	}
 
+	if (resend_igmp < 0 || resend_igmp > 255) {
+		pr_warning("Warning: resend_igmp (%d) should be between "
+			   "0 and 255, resetting to %d\n",
+			   resend_igmp, BOND_DEFAULT_RESEND_IGMP);
+		resend_igmp = BOND_DEFAULT_RESEND_IGMP;
+	}
+
 	/* reset values for TLB/ALB */
 	if ((bond_mode == BOND_MODE_TLB) ||
 	    (bond_mode == BOND_MODE_ALB)) {
@@ -5105,6 +5119,7 @@
 	params->fail_over_mac = fail_over_mac_value;
 	params->tx_queues = tx_queues;
 	params->all_slaves_active = all_slaves_active;
+	params->resend_igmp = resend_igmp;
 
 	if (primary) {
 		strncpy(params->primary, primary, IFNAMSIZ);