releases/4.6.5/geneve-fix-max_mtu-setting.patch

   1 From foo@baz Thu Jul 14 07:36:41 JST 2016
   2 From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
   3 Date: Sat, 2 Jul 2016 15:02:48 +0800
   4 Subject: geneve: fix max_mtu setting
   5
   6 From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
   7
   8 [ Upstream commit d5d5e8d55732c7c35c354e45e3b0af2795978a57 ]
   9
  10 For ipv6+udp+geneve encapsulation data, the max_mtu should subtract
  11 sizeof(ipv6hdr), instead of sizeof(iphdr).
  12
  13 Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
  14 Signed-off-by: David S. Miller <davem@davemloft.net>
  15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  16 ---
  17  drivers/net/geneve.c |    9 +++++++--
  18  1 file changed, 7 insertions(+), 2 deletions(-)
  19
  20 --- a/drivers/net/geneve.c
  21 +++ b/drivers/net/geneve.c
  22 @@ -1092,12 +1092,17 @@ static netdev_tx_t geneve_xmit(struct sk
  23
  24  static int __geneve_change_mtu(struct net_device *dev, int new_mtu, bool strict)
  25  {
  26 +       struct geneve_dev *geneve = netdev_priv(dev);
  27         /* The max_mtu calculation does not take account of GENEVE
  28          * options, to avoid excluding potentially valid
  29          * configurations.
  30          */
  31 -       int max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - sizeof(struct iphdr)
  32 -               - dev->hard_header_len;
  33 +       int max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - dev->hard_header_len;
  34 +
  35 +       if (geneve->remote.sa.sa_family == AF_INET6)
  36 +               max_mtu -= sizeof(struct ipv6hdr);
  37 +       else
  38 +               max_mtu -= sizeof(struct iphdr);
  39
  40         if (new_mtu < 68)
  41                 return -EINVAL;