ip_gre: fix IFLA_MTU ignored on NEWLINK

It's safe to remove the setting of dev's needed_headroom and mtu in
__gre_tunnel_init, as discussed in [1], ip_tunnel_newlink can do it
properly.

Now Eric noticed that it could cover the mtu value set in do_setlink
when creating a ip_gre dev. It makes IFLA_MTU param not take effect.

So this patch is to remove them to make IFLA_MTU work, as in other
ipv4 tunnels.

  [1]: https://patchwork.ozlabs.org/patch/823504/

Fixes: c544193214 ("GRE: Refactor GRE tunneling code.")
Reported-by: Eric Garver <e@erig.me>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Xin Long 2018-02-27 19:19:39 +08:00 committed by David S. Miller
parent 9c2c2e62df
commit ffc2b6ee41

View File

@ -970,9 +970,6 @@ static void __gre_tunnel_init(struct net_device *dev)
t_hlen = tunnel->hlen + sizeof(struct iphdr);
dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4;
dev->mtu = ETH_DATA_LEN - t_hlen - 4;
dev->features |= GRE_FEATURES;
dev->hw_features |= GRE_FEATURES;
@ -1290,8 +1287,6 @@ static int erspan_tunnel_init(struct net_device *dev)
erspan_hdr_len(tunnel->erspan_ver);
t_hlen = tunnel->hlen + sizeof(struct iphdr);
dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4;
dev->mtu = ETH_DATA_LEN - t_hlen - 4;
dev->features |= GRE_FEATURES;
dev->hw_features |= GRE_FEATURES;
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;