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authorBreno Leitao <leitao@linux.vnet.ibm.com>2008-09-02 17:28:58 -0700
committerDavid S. Miller <davem@davemloft.net>2008-09-02 17:28:58 -0700
commit06770843c2f0f929a6e0c758dc433902a01aabfb (patch)
treeb579cbcf3f960289cfe5c586f7e38a03abc88df6
parent9d7d74029e0f5fde3b88b39892b9b9cfdf4ea10a (diff)
downloadlwn-06770843c2f0f929a6e0c758dc433902a01aabfb.tar.gz
lwn-06770843c2f0f929a6e0c758dc433902a01aabfb.zip
ipv: Re-enable IP when MTU > 68
Re-enable IP when the MTU gets back to a valid size. This patch just checks if the in_dev is NULL on a NETDEV_CHANGEMTU event and if MTU is valid (bigger than 68), then re-enable in_dev. Also a function that checks valid MTU size was created. Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/devinet.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 91d3d96805d0..b12dae2b0b2d 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1029,6 +1029,11 @@ skip:
}
}
+static inline bool inetdev_valid_mtu(unsigned mtu)
+{
+ return mtu >= 68;
+}
+
/* Called only under RTNL semaphore */
static int inetdev_event(struct notifier_block *this, unsigned long event,
@@ -1048,6 +1053,10 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
}
+ } else if (event == NETDEV_CHANGEMTU) {
+ /* Re-enabling IP */
+ if (inetdev_valid_mtu(dev->mtu))
+ in_dev = inetdev_init(dev);
}
goto out;
}
@@ -1058,7 +1067,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
dev->ip_ptr = NULL;
break;
case NETDEV_UP:
- if (dev->mtu < 68)
+ if (!inetdev_valid_mtu(dev->mtu))
break;
if (dev->flags & IFF_LOOPBACK) {
struct in_ifaddr *ifa;
@@ -1080,9 +1089,9 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
ip_mc_down(in_dev);
break;
case NETDEV_CHANGEMTU:
- if (dev->mtu >= 68)
+ if (inetdev_valid_mtu(dev->mtu))
break;
- /* MTU falled under 68, disable IP */
+ /* disable IP when MTU is not enough */
case NETDEV_UNREGISTER:
inetdev_destroy(in_dev);
break;