[09/10] batman-adv: Add lower layer needed_(head|tail)room to own ones
Commit Message
From: Sven Eckelmann <sven@narfation.org>
The maximum of hard_header_len and maximum of all needed_(head|tail)room of
all slave interfaces of a batman-adv device must be used to define the
batman-adv device needed_(head|tail)room. This is required to avoid too
small buffer problems when these slave devices try to send the encapsulated
packet in a tx path without the possibility to resize the skbuff.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
---
net/batman-adv/hard-interface.c | 41 +++++++++++++++++++++++++++++++++++++++++
net/batman-adv/soft-interface.c | 2 --
2 files changed, 41 insertions(+), 2 deletions(-)
@@ -252,6 +252,44 @@ static void batadv_check_known_mac_addr(const struct net_device *net_dev)
rcu_read_unlock();
}
+/**
+ * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
+ * @soft_iface: netdev struct of the mesh interface
+ */
+static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
+{
+ const struct batadv_hard_iface *hard_iface;
+ unsigned short lower_header_len = ETH_HLEN;
+ unsigned short lower_headroom = 0;
+ unsigned short lower_tailroom = 0;
+ unsigned short needed_headroom;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
+ continue;
+
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ lower_header_len = max_t(unsigned short, lower_header_len,
+ hard_iface->net_dev->hard_header_len);
+
+ lower_headroom = max_t(unsigned short, lower_headroom,
+ hard_iface->net_dev->needed_headroom);
+
+ lower_tailroom = max_t(unsigned short, lower_tailroom,
+ hard_iface->net_dev->needed_tailroom);
+ }
+ rcu_read_unlock();
+
+ needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
+ needed_headroom += batadv_max_header_len();
+
+ soft_iface->needed_headroom = needed_headroom;
+ soft_iface->needed_tailroom = lower_tailroom;
+}
+
int batadv_hardif_min_mtu(struct net_device *soft_iface)
{
struct batadv_priv *bat_priv = netdev_priv(soft_iface);
@@ -474,6 +512,8 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
"Not using interface %s (retrying later): interface not active\n",
hard_iface->net_dev->name);
+ batadv_hardif_recalc_extra_skbroom(soft_iface);
+
/* begin scheduling originator messages on that interface */
batadv_schedule_bat_ogm(hard_iface);
@@ -529,6 +569,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
dev_put(hard_iface->soft_iface);
netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
+ batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
/* nobody uses this interface anymore */
if (!bat_priv->num_ifaces) {
@@ -947,8 +947,6 @@ static void batadv_softif_init_early(struct net_device *dev)
* have not been initialized yet
*/
dev->mtu = ETH_DATA_LEN;
- /* reserve more space in the skbuff for our header */
- dev->hard_header_len = batadv_max_header_len();
/* generate random address */
eth_hw_addr_random(dev);