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authorSabrina Dubroca <sd@queasysnail.net>2018-10-09 17:48:14 +0200
committerDavid S. Miller <davem@davemloft.net>2018-10-10 22:44:46 -0700
commitaf7d6cce53694a88d6a1bb60c9a239a6a5144459 (patch)
treedf65be744e3e4f829bd8d361276ed0516c9de298 /net/ipv4/fib_frontend.c
parent7abab7b9b498650404800a08765f44929fee8f31 (diff)
net: ipv4: update fnhe_pmtu when first hop's MTU changes
Since commit 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions"), exceptions get deprecated separately from cached routes. In particular, administrative changes don't clear PMTU anymore. As Stefano described in commit e9fa1495d738 ("ipv6: Reflect MTU changes on PMTU of exceptions for MTU-less routes"), the PMTU discovered before the local MTU change can become stale: - if the local MTU is now lower than the PMTU, that PMTU is now incorrect - if the local MTU was the lowest value in the path, and is increased, we might discover a higher PMTU Similarly to what commit e9fa1495d738 did for IPv6, update PMTU in those cases. If the exception was locked, the discovered PMTU was smaller than the minimal accepted PMTU. In that case, if the new local MTU is smaller than the current PMTU, let PMTU discovery figure out if locking of the exception is still needed. To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU notifier. By the time the notifier is called, dev->mtu has been changed. This patch adds the old MTU as additional information in the notifier structure, and a new call_netdevice_notifiers_u32() function. Fixes: 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/fib_frontend.c')
-rw-r--r--net/ipv4/fib_frontend.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 2998b0e47d4b..0113993e9b2c 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -1243,7 +1243,8 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
- struct netdev_notifier_changeupper_info *info;
+ struct netdev_notifier_changeupper_info *upper_info = ptr;
+ struct netdev_notifier_info_ext *info_ext = ptr;
struct in_device *in_dev;
struct net *net = dev_net(dev);
unsigned int flags;
@@ -1278,16 +1279,19 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo
fib_sync_up(dev, RTNH_F_LINKDOWN);
else
fib_sync_down_dev(dev, event, false);
- /* fall through */
+ rt_cache_flush(net);
+ break;
case NETDEV_CHANGEMTU:
+ fib_sync_mtu(dev, info_ext->ext.mtu);
rt_cache_flush(net);
break;
case NETDEV_CHANGEUPPER:
- info = ptr;
+ upper_info = ptr;
/* flush all routes if dev is linked to or unlinked from
* an L3 master device (e.g., VRF)
*/
- if (info->upper_dev && netif_is_l3_master(info->upper_dev))
+ if (upper_info->upper_dev &&
+ netif_is_l3_master(upper_info->upper_dev))
fib_disable_ip(dev, NETDEV_DOWN, true);
break;
}