From b7b0b1d290cc89c39607dd47f8047e1071e65692 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Mon, 26 Oct 2015 11:06:33 -0700 Subject: [PATCH] ipv6: recreate ipv6 link-local addresses when increasing MTU over IPV6_MIN_MTU This change makes it so that we reinitialize the interface if the MTU is increased back above IPV6_MIN_MTU and the interface is up. Cc: Hannes Frederic Sowa Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 46 ++++++++++++++++++++++++++------------------- 1 file changed, 27 insertions(+), 19 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index d0c685cdc345..d72fa90d6feb 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3147,6 +3147,32 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, } break; + case NETDEV_CHANGEMTU: + /* if MTU under IPV6_MIN_MTU stop IPv6 on this interface. */ + if (dev->mtu < IPV6_MIN_MTU) { + addrconf_ifdown(dev, 1); + break; + } + + if (idev) { + rt6_mtu_change(dev, dev->mtu); + idev->cnf.mtu6 = dev->mtu; + break; + } + + /* allocate new idev */ + idev = ipv6_add_dev(dev); + if (IS_ERR(idev)) + break; + + /* device is still not ready */ + if (!(idev->if_flags & IF_READY)) + break; + + run_pending = 1; + + /* fall through */ + case NETDEV_UP: case NETDEV_CHANGE: if (dev->flags & IFF_SLAVE) @@ -3170,7 +3196,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, idev->if_flags |= IF_READY; run_pending = 1; } - } else { + } else if (event == NETDEV_CHANGE) { if (!addrconf_qdisc_ok(dev)) { /* device is still not ready. */ break; @@ -3235,24 +3261,6 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, } break; - case NETDEV_CHANGEMTU: - if (idev && dev->mtu >= IPV6_MIN_MTU) { - rt6_mtu_change(dev, dev->mtu); - idev->cnf.mtu6 = dev->mtu; - break; - } - - if (!idev && dev->mtu >= IPV6_MIN_MTU) { - idev = ipv6_add_dev(dev); - if (!IS_ERR(idev)) - break; - } - - /* - * if MTU under IPV6_MIN_MTU. - * Stop IPv6 on this interface. - */ - case NETDEV_DOWN: case NETDEV_UNREGISTER: /*