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>

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index c311aed9bd02..01b4c3f5d9e7 100644
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -1592,6 +1592,49 @@ out:
 static DEVICE_ATTR(all_slaves_active, S_IRUGO | S_IWUSR,
 		   bonding_show_slaves_active, bonding_store_slaves_active);
 
+/*
+ * Show and set the number of IGMP membership reports to send on link failure
+ */
+static ssize_t bonding_show_resend_igmp(struct device *d,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct bonding *bond = to_bond(d);
+
+	return sprintf(buf, "%d\n", bond->params.resend_igmp);
+}
+
+static ssize_t bonding_store_resend_igmp(struct device *d,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	int new_value, ret = count;
+	struct bonding *bond = to_bond(d);
+
+	if (sscanf(buf, "%d", &new_value) != 1) {
+		pr_err("%s: no resend_igmp value specified.\n",
+		       bond->dev->name);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (new_value < 0) {
+		pr_err("%s: Invalid resend_igmp value %d not in range 0-255; rejected.\n",
+		       bond->dev->name, new_value);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	pr_info("%s: Setting resend_igmp to %d.\n",
+		bond->dev->name, new_value);
+	bond->params.resend_igmp = new_value;
+out:
+	return ret;
+}
+
+static DEVICE_ATTR(resend_igmp, S_IRUGO | S_IWUSR,
+		   bonding_show_resend_igmp, bonding_store_resend_igmp);
+
 static struct attribute *per_bond_attrs[] = {
 	&dev_attr_slaves.attr,
 	&dev_attr_mode.attr,
@@ -1619,6 +1662,7 @@ static struct attribute *per_bond_attrs[] = {
 	&dev_attr_ad_partner_mac.attr,
 	&dev_attr_queue_id.attr,
 	&dev_attr_all_slaves_active.attr,
+	&dev_attr_resend_igmp.attr,
 	NULL,
 };