bonding: send IPv6 neighbor advertisement on failover
This patch adds better IPv6 failover support for bonding devices,
especially when in active-backup mode and there are only IPv6 addresses
configured, as reported by Alex Sidorenko.
- Creates a new file, net/drivers/bonding/bond_ipv6.c, for the
IPv6-specific routines. Both regular bonds and VLANs over bonds
are supported.
- Adds a new tunable, num_unsol_na, to limit the number of unsolicited
IPv6 Neighbor Advertisements that are sent on a failover event.
Default is 1.
- Creates two new IPv6 neighbor discovery functions:
ndisc_build_skb()
ndisc_send_skb()
These were required to support VLANs since we have to be able to
add the VLAN id to the skb since ndisc_send_na() and friends
shouldn't be asked to do this. These two routines are basically
__ndisc_send() split into two pieces, in a slightly different order.
- Updates Documentation/networking/bonding.txt and bumps the rev of bond
support to 3.4.0.
On failover, this new code will generate one packet:
- An unsolicited IPv6 Neighbor Advertisement, which helps the switch
learn that the address has moved to the new slave.
Testing has shown that sending just the NA results in pretty good
behavior when in active-back mode, I saw no lost ping packets for example.
Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 39575d7..798d98c 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -89,6 +89,7 @@
static int max_bonds = BOND_DEFAULT_MAX_BONDS;
static int num_grat_arp = 1;
+static int num_unsol_na = 1;
static int miimon = BOND_LINK_MON_INTERV;
static int updelay = 0;
static int downdelay = 0;
@@ -107,6 +108,8 @@
MODULE_PARM_DESC(max_bonds, "Max number of bonded devices");
module_param(num_grat_arp, int, 0644);
MODULE_PARM_DESC(num_grat_arp, "Number of gratuitous ARP packets to send on failover event");
+module_param(num_unsol_na, int, 0644);
+MODULE_PARM_DESC(num_unsol_na, "Number of unsolicited IPv6 Neighbor Advertisements packets to send on failover event");
module_param(miimon, int, 0);
MODULE_PARM_DESC(miimon, "Link check interval in milliseconds");
module_param(updelay, int, 0);
@@ -242,14 +245,13 @@
dprintk("bond: %s, vlan id %d\n",
(bond ? bond->dev->name: "None"), vlan_id);
- vlan = kmalloc(sizeof(struct vlan_entry), GFP_KERNEL);
+ vlan = kzalloc(sizeof(struct vlan_entry), GFP_KERNEL);
if (!vlan) {
return -ENOMEM;
}
INIT_LIST_HEAD(&vlan->vlan_list);
vlan->vlan_id = vlan_id;
- vlan->vlan_ip = 0;
write_lock_bh(&bond->lock);
@@ -1208,6 +1210,9 @@
bond->send_grat_arp = bond->params.num_grat_arp;
bond_send_gratuitous_arp(bond);
+ bond->send_unsol_na = bond->params.num_unsol_na;
+ bond_send_unsolicited_na(bond);
+
write_unlock_bh(&bond->curr_slave_lock);
read_unlock(&bond->lock);
@@ -2463,6 +2468,12 @@
read_unlock(&bond->curr_slave_lock);
}
+ if (bond->send_unsol_na) {
+ read_lock(&bond->curr_slave_lock);
+ bond_send_unsolicited_na(bond);
+ read_unlock(&bond->curr_slave_lock);
+ }
+
if (bond_miimon_inspect(bond)) {
read_unlock(&bond->lock);
rtnl_lock();
@@ -3158,6 +3169,12 @@
read_unlock(&bond->curr_slave_lock);
}
+ if (bond->send_unsol_na) {
+ read_lock(&bond->curr_slave_lock);
+ bond_send_unsolicited_na(bond);
+ read_unlock(&bond->curr_slave_lock);
+ }
+
if (bond_ab_arp_inspect(bond, delta_in_ticks)) {
read_unlock(&bond->lock);
rtnl_lock();
@@ -3827,6 +3844,7 @@
write_lock_bh(&bond->lock);
bond->send_grat_arp = 0;
+ bond->send_unsol_na = 0;
/* signal timers not to re-arm */
bond->kill_timers = 1;
@@ -4542,6 +4560,7 @@
bond->primary_slave = NULL;
bond->dev = bond_dev;
bond->send_grat_arp = 0;
+ bond->send_unsol_na = 0;
bond->setup_by_slave = 0;
INIT_LIST_HEAD(&bond->vlan_list);
@@ -4791,6 +4810,13 @@
num_grat_arp = 1;
}
+ if (num_unsol_na < 0 || num_unsol_na > 255) {
+ printk(KERN_WARNING DRV_NAME
+ ": Warning: num_unsol_na (%d) not in range 0-255 so it "
+ "was reset to 1 \n", num_unsol_na);
+ num_unsol_na = 1;
+ }
+
/* reset values for 802.3ad */
if (bond_mode == BOND_MODE_8023AD) {
if (!miimon) {
@@ -4992,6 +5018,7 @@
params->xmit_policy = xmit_hashtype;
params->miimon = miimon;
params->num_grat_arp = num_grat_arp;
+ params->num_unsol_na = num_unsol_na;
params->arp_interval = arp_interval;
params->arp_validate = arp_validate_value;
params->updelay = updelay;
@@ -5144,6 +5171,7 @@
register_netdevice_notifier(&bond_netdev_notifier);
register_inetaddr_notifier(&bond_inetaddr_notifier);
+ bond_register_ipv6_notifier();
goto out;
err:
@@ -5166,6 +5194,7 @@
{
unregister_netdevice_notifier(&bond_netdev_notifier);
unregister_inetaddr_notifier(&bond_inetaddr_notifier);
+ bond_unregister_ipv6_notifier();
bond_destroy_sysfs();