ip6gretap: Fix MTU to allow for Ethernet header

When we were creating an ip6gretap interface the MTU was about 6 bytes
short of what was needed.  It turns out we were not taking the Ethernet
header into account and as a result we were eating into the 8 bytes
reserved for the encap limit.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Duyck 2016-04-14 15:33:45 -04:00 committed by David S. Miller
parent aed069df09
commit a9e242ca43
1 changed files with 2 additions and 0 deletions

View File

@ -987,6 +987,8 @@ static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
dev->mtu = rt->dst.dev->mtu - addend;
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu -= 8;
if (dev->type == ARPHRD_ETHER)
dev->mtu -= ETH_HLEN;
if (dev->mtu < IPV6_MIN_MTU)
dev->mtu = IPV6_MIN_MTU;