From 305d552accae6afb859c493ebc7d98ca3371dae2 Mon Sep 17 00:00:00 2001 From: Brian Haley Date: Tue, 4 Nov 2008 17:51:14 -0800 Subject: 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 Signed-off-by: Jay Vosburgh Signed-off-by: Jeff Garzik --- drivers/net/bonding/bond_sysfs.c | 42 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'drivers/net/bonding/bond_sysfs.c') diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c index e400d7dfdfc8..8788e3e33852 100644 --- a/drivers/net/bonding/bond_sysfs.c +++ b/drivers/net/bonding/bond_sysfs.c @@ -983,6 +983,47 @@ out: return ret; } static DEVICE_ATTR(num_grat_arp, S_IRUGO | S_IWUSR, bonding_show_n_grat_arp, bonding_store_n_grat_arp); + +/* + * Show and set the number of unsolicted NA's to send after a failover event. + */ +static ssize_t bonding_show_n_unsol_na(struct device *d, + struct device_attribute *attr, + char *buf) +{ + struct bonding *bond = to_bond(d); + + return sprintf(buf, "%d\n", bond->params.num_unsol_na); +} + +static ssize_t bonding_store_n_unsol_na(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) { + printk(KERN_ERR DRV_NAME + ": %s: no num_unsol_na value specified.\n", + bond->dev->name); + ret = -EINVAL; + goto out; + } + if (new_value < 0 || new_value > 255) { + printk(KERN_ERR DRV_NAME + ": %s: Invalid num_unsol_na value %d not in range 0-255; rejected.\n", + bond->dev->name, new_value); + ret = -EINVAL; + goto out; + } else { + bond->params.num_unsol_na = new_value; + } +out: + return ret; +} +static DEVICE_ATTR(num_unsol_na, S_IRUGO | S_IWUSR, bonding_show_n_unsol_na, bonding_store_n_unsol_na); + /* * Show and set the MII monitor interval. There are two tricky bits * here. First, if MII monitoring is activated, then we must disable @@ -1420,6 +1461,7 @@ static struct attribute *per_bond_attrs[] = { &dev_attr_lacp_rate.attr, &dev_attr_xmit_hash_policy.attr, &dev_attr_num_grat_arp.attr, + &dev_attr_num_unsol_na.attr, &dev_attr_miimon.attr, &dev_attr_primary.attr, &dev_attr_use_carrier.attr, -- cgit v1.2.3