batman-adv/patches/0001-batman-adv-Add-lower-layer-header-length-to-headroom.patch

   1 batman-adv: Add lower layer header length to headroom
   2
   3 The maximum of hard_header_len and needed_headroom of all slave interfaces
   4 of a batman-adv device must be used to define the batman-adv device
   5 headroom/header_len. This is required to avoid too small headroom problems
   6 when these slave devices try to send the encapsulated packet.
   7
   8 The batman-adv therefore uses:
   9
  10         needed_headroom = max(0, dev[0].needed_headroom, ...,
  11                               dev[n].needed_headroom)
  12         hard_header_len = max(ETH_HLEN, dev[0].hard_header_len, ...,
  13                               dev[n].hard_header_len) + ETH_HLEN +
  14                           max(sizeof(batadv_*cast_packet))
  15
  16 Signed-off-by: Sven Eckelmann <sven@narfation.org>
  17 ---
  18  net/batman-adv/hard-interface.c | 33 +++++++++++++++++++++++++++++++++
  19  net/batman-adv/soft-interface.c |  2 +-
  20  2 files changed, 34 insertions(+), 1 deletion(-)
  21
  22 diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
  23 index f4a15d2e5eaf..a501aae1077b 100644
  24 --- a/net/batman-adv/hard-interface.c
  25 +++ b/net/batman-adv/hard-interface.c
  26 @@ -252,12 +252,45 @@ static void batadv_check_known_mac_addr(const struct net_device *net_dev)
  27         rcu_read_unlock();
  28  }
  29
  30 +/**
  31 + * batadv_hardif_recalc_headroom() - Recalculate skbuff headroom parameters
  32 + * @soft_iface: netdev struct of the mesh interface
  33 + */
  34 +static void batadv_hardif_recalc_headroom(struct net_device *soft_iface)
  35 +{
  36 +       const struct batadv_hard_iface *hard_iface;
  37 +       unsigned short hard_header_len = ETH_HLEN;
  38 +       unsigned short needed_headroom = 0;
  39 +
  40 +       rcu_read_lock();
  41 +       list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  42 +               if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
  43 +                   (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
  44 +                       continue;
  45 +
  46 +               if (hard_iface->soft_iface != soft_iface)
  47 +                       continue;
  48 +
  49 +               hard_header_len = max_t(unsigned short, hard_header_len,
  50 +                                       hard_iface->net_dev->hard_header_len);
  51 +
  52 +               needed_headroom = max_t(unsigned short, needed_headroom,
  53 +                                       hard_iface->net_dev->needed_headroom);
  54 +       }
  55 +       rcu_read_unlock();
  56 +
  57 +       soft_iface->needed_headroom = needed_headroom;
  58 +       soft_iface->hard_header_len = hard_header_len + batadv_max_header_len();
  59 +}
  60 +
  61  int batadv_hardif_min_mtu(struct net_device *soft_iface)
  62  {
  63         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  64         const struct batadv_hard_iface *hard_iface;
  65         int min_mtu = INT_MAX;
  66
  67 +       batadv_hardif_recalc_headroom(soft_iface);
  68 +
  69         rcu_read_lock();
  70         list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
  71                 if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
  72 diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
  73 index 36b23f31df2a..b4c110791203 100644
  74 --- a/net/batman-adv/soft-interface.c
  75 +++ b/net/batman-adv/soft-interface.c
  76 @@ -948,7 +948,7 @@ static void batadv_softif_init_early(struct net_device *dev)
  77          */
  78         dev->mtu = ETH_DATA_LEN;
  79         /* reserve more space in the skbuff for our header */
  80 -       dev->hard_header_len = batadv_max_header_len();
  81 +       dev->hard_header_len = ETH_HLEN + batadv_max_header_len();
  82
  83         /* generate random address */
  84         eth_hw_addr_random(dev);
  85 --
  86 2.5.0
  87
  88