From c2edacf80e155ef54ae4774379d461b60896bc2e Mon Sep 17 00:00:00 2001 From: Jay Vosburgh Date: Mon, 9 Jul 2007 10:42:47 -0700 Subject: bonding / ipv6: no addrconf for slaves separately from master At present, when a device is enslaved to bonding, if ipv6 is active then addrconf will be initated on the slave (because it is closed then opened during the enslavement processing). This causes DAD and RS packets to be sent from the slave. These packets in turn can confuse switches that perform ipv6 snooping, causing them to incorrectly update their forwarding tables (if, e.g., the slave being added is an inactve backup that won't be used right away) and direct traffic away from the active slave to a backup slave (where the incoming packets will be dropped). This patch alters the behavior so that addrconf will only run on the master device itself. I believe this is logically correct, as it prevents slaves from having an IPv6 identity independent from the master. This is consistent with the IPv4 behavior for bonding. This is accomplished by (a) having bonding set IFF_SLAVE sooner in the enslavement processing than currently occurs (before open, not after), and (b) having ipv6 addrconf ignore UP and CHANGE events on slave devices. The eql driver also uses the IFF_SLAVE flag. I inspected eql, and I believe this change is reasonable for its usage of IFF_SLAVE, but I did not test it. Signed-off-by: Jay Vosburgh Signed-off-by: Jeff Garzik --- net/ipv6/addrconf.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f96ed76d8fa4..79b79f3de24c 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2268,6 +2268,9 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, break; case NETDEV_UP: case NETDEV_CHANGE: + if (dev->flags & IFF_SLAVE) + break; + if (event == NETDEV_UP) { if (!netif_carrier_ok(dev)) { /* device is not ready yet. */ -- cgit v1.2.3