diff options
| author | Sabrina Dubroca <sd@queasysnail.net> | 2018-10-09 17:48:14 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-18 09:16:17 +0200 |
| commit | 9b4869cf385aa16f89c0f019eed4ec4e36aa441c (patch) | |
| tree | ec6453ec268f8fedd9e80bdaea2a854775bf9d6e /include/net | |
| parent | 6c61dae979ae39850a3a9945f93e83e5b5baf31c (diff) | |
net: ipv4: update fnhe_pmtu when first hop's MTU changes
[ Upstream commit af7d6cce53694a88d6a1bb60c9a239a6a5144459 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/ip_fib.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 5c5d344c0629..32df52869a14 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -372,6 +372,7 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev); int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); int fib_sync_down_addr(struct net_device *dev, __be32 local); int fib_sync_up(struct net_device *dev, unsigned int nh_flags); +void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); #ifdef CONFIG_IP_ROUTE_MULTIPATH int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4, |