diff options
| author | Anders Franzen <Anders.Franzen@ericsson.com> | 2010-11-24 05:47:18 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-12-01 10:55:47 -0800 |
| commit | 381601e5bbae78d7c18d946fe874a63957edea13 (patch) | |
| tree | 2aa2fa29329265ea781001a8e4365977d6caa322 | |
| parent | 25888e30319f8896fc656fc68643e6a078263060 (diff) | |
Make the ip6_tunnel reflect the true mtu.
The ip6_tunnel always assumes it consumes 40 bytes (ip6 hdr) of the mtu of the
underlaying device. So for a normal ethernet bearer, the mtu of the ip6_tunnel is
1460.
However, when creating a tunnel the encap limit option is enabled by default, and it
consumes 8 bytes more, so the true mtu shall be 1452.
I dont really know if this breaks some statement in some RFC, so this is a request for
comments.
Signed-off-by: Anders Franzen <anders.franzen@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 2a59610c2a5..70e891a20fb 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1175,6 +1175,8 @@ static void ip6_tnl_link_config(struct ip6_tnl *t) sizeof (struct ipv6hdr); dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); + if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) + dev->mtu-=8; if (dev->mtu < IPV6_MIN_MTU) dev->mtu = IPV6_MIN_MTU; @@ -1363,12 +1365,17 @@ static const struct net_device_ops ip6_tnl_netdev_ops = { static void ip6_tnl_dev_setup(struct net_device *dev) { + struct ip6_tnl *t; + dev->netdev_ops = &ip6_tnl_netdev_ops; dev->destructor = ip6_dev_free; dev->type = ARPHRD_TUNNEL6; dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); + t = netdev_priv(dev); + if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) + dev->mtu-=8; dev->flags |= IFF_NOARP; dev->addr_len = sizeof(struct in6_addr); dev->features |= NETIF_F_NETNS_LOCAL; |