[net-next PATCH v2] ipv6: recreate ipv6 link-local addresses when increasing MTU over IPV6_MIN_MTU
From: Alexander Duyck <hidden>
Date: 2015-10-26 18:06:35
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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 <redacted> Signed-off-by: Alexander Duyck <redacted> --- 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: /*