ip6_gre: process toobig in a better way
Now ip6gre processes toobig icmp packet by setting gre dev's mtu in
ip6gre_err, which would cause few things not good:
- It couldn't set mtu with dev_set_mtu due to it's not in user context,
which causes route cache and idev->cnf.mtu6 not to be updated.
- It has to update sk dst pmtu in tx path according to gredev->mtu for
ip6gre, while it updates pmtu again according to lower dst pmtu in
ip6_tnl_xmit.
- To change dev->mtu by toobig icmp packet is not a good idea, it should
only work on pmtu.
This patch is to process toobig by updating the lower dst's pmtu, as later
sk dst pmtu will be updated in ip6_tnl_xmit, the same way as in ip4gre.
Note that gre dev's mtu will not be updated any more, it doesn't make any
sense to change dev's mtu after receiving a toobig packet.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed
