batman-adv/patches/0002-batman-adv-Add-lower-layer-needed_-head-tail-room-to.patch

   1 From e2b4301f4e2d3695ed2024880d2295223cb2f857 Mon Sep 17 00:00:00 2001
   2 From: Sven Eckelmann <sven@narfation.org>
   3 Date: Fri, 7 Aug 2015 19:28:42 +0200
   4 Subject: [PATCH 2/9] batman-adv: Add lower layer needed_(head|tail)room to own
   5  ones
   6
   7 The maximum of hard_header_len and maximum of all needed_(head|tail)room of
   8 all slave interfaces of a batman-adv device must be used to define the
   9 batman-adv device needed_(head|tail)room. This is required to avoid too
  10 small buffer problems when these slave devices try to send the encapsulated
  11 packet in a tx path without the possibility to resize the skbuff.
  12
  13 Signed-off-by: Sven Eckelmann <sven@narfation.org>
  14 Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
  15 ---
  16  net/batman-adv/hard-interface.c | 41 +++++++++++++++++++++++++++++++++++++++++
  17  net/batman-adv/soft-interface.c |  2 --
  18  2 files changed, 41 insertions(+), 2 deletions(-)
  19
  20 diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
  21 index 0565b20..f11345e 100644
  22 --- a/net/batman-adv/hard-interface.c
  23 +++ b/net/batman-adv/hard-interface.c
  24 @@ -252,6 +252,44 @@ static void batadv_check_known_mac_addr(const struct net_device *net_dev)
  25         rcu_read_unlock();
  26  }
  27
  28 +/**
  29 + * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
  30 + * @soft_iface: netdev struct of the mesh interface
  31 + */
  32 +static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
  33 +{
  34 +       const struct batadv_hard_iface *hard_iface;
  35 +       unsigned short lower_header_len = ETH_HLEN;
  36 +       unsigned short lower_headroom = 0;
  37 +       unsigned short lower_tailroom = 0;
  38 +       unsigned short needed_headroom;
  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_NOT_IN_USE)
  43 +                       continue;
  44 +
  45 +               if (hard_iface->soft_iface != soft_iface)
  46 +                       continue;
  47 +
  48 +               lower_header_len = max_t(unsigned short, lower_header_len,
  49 +                                        hard_iface->net_dev->hard_header_len);
  50 +
  51 +               lower_headroom = max_t(unsigned short, lower_headroom,
  52 +                                      hard_iface->net_dev->needed_headroom);
  53 +
  54 +               lower_tailroom = max_t(unsigned short, lower_tailroom,
  55 +                                      hard_iface->net_dev->needed_tailroom);
  56 +       }
  57 +       rcu_read_unlock();
  58 +
  59 +       needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
  60 +       needed_headroom += batadv_max_header_len();
  61 +
  62 +       soft_iface->needed_headroom = needed_headroom;
  63 +       soft_iface->needed_tailroom = lower_tailroom;
  64 +}
  65 +
  66  int batadv_hardif_min_mtu(struct net_device *soft_iface)
  67  {
  68         struct batadv_priv *bat_priv = netdev_priv(soft_iface);
  69 @@ -474,6 +512,8 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
  70                            "Not using interface %s (retrying later): interface not active\n",
  71                            hard_iface->net_dev->name);
  72
  73 +       batadv_hardif_recalc_extra_skbroom(soft_iface);
  74 +
  75         /* begin scheduling originator messages on that interface */
  76         batadv_schedule_bat_ogm(hard_iface);
  77
  78 @@ -529,6 +569,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
  79         dev_put(hard_iface->soft_iface);
  80
  81         netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
  82 +       batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
  83
  84         /* nobody uses this interface anymore */
  85         if (!bat_priv->num_ifaces) {
  86 diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
  87 index 51cda3a..10f6448 100644
  88 --- a/net/batman-adv/soft-interface.c
  89 +++ b/net/batman-adv/soft-interface.c
  90 @@ -947,8 +947,6 @@ static void batadv_softif_init_early(struct net_device *dev)
  91          * have not been initialized yet
  92          */
  93         dev->mtu = ETH_DATA_LEN;
  94 -       /* reserve more space in the skbuff for our header */
  95 -       dev->hard_header_len = batadv_max_header_len();
  96
  97         /* generate random address */
  98         eth_hw_addr_random(dev);
  99 --
 100 2.5.0
 101