The maximum of hard_header_len and needed_headroom of all slave interfaces
of a batman-adv device must be used to define the batman-adv device
headroom/header_len. This is required to avoid too small headroom problems
when these slave devices try to send the encapsulated packet.
The batman-adv therefore uses:
needed_headroom = max(0, dev[0].needed_headroom, ...,
dev[n].needed_headroom)
hard_header_len = max(ETH_HLEN, dev[0].hard_header_len, ...,
dev[n].hard_header_len) + ETH_HLEN +
max(sizeof(batadv_*cast_packet))
Signed-off-by: Sven Eckelmann <[email protected]>
---
net/batman-adv/hard-interface.c | 33 +++++++++++++++++++++++++++++++++
net/batman-adv/soft-interface.c | 2 +-
2 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index f4a15d2e5eaf..a501aae1077b 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -252,12 +252,45 @@ static void batadv_check_known_mac_addr(const struct
net_device *net_dev)
rcu_read_unlock();
}
+/**
+ * batadv_hardif_recalc_headroom() - Recalculate skbuff headroom parameters
+ * @soft_iface: netdev struct of the mesh interface
+ */
+static void batadv_hardif_recalc_headroom(struct net_device *soft_iface)
+{
+ const struct batadv_hard_iface *hard_iface;
+ unsigned short hard_header_len = ETH_HLEN;
+ unsigned short needed_headroom = 0;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
+ (hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED))
+ continue;
+
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ hard_header_len = max_t(unsigned short, hard_header_len,
+ hard_iface->net_dev->hard_header_len);
+
+ needed_headroom = max_t(unsigned short, needed_headroom,
+ hard_iface->net_dev->needed_headroom);
+ }
+ rcu_read_unlock();
+
+ soft_iface->needed_headroom = needed_headroom;
+ soft_iface->hard_header_len = hard_header_len + batadv_max_header_len();
+}
+
int batadv_hardif_min_mtu(struct net_device *soft_iface)
{
struct batadv_priv *bat_priv = netdev_priv(soft_iface);
const struct batadv_hard_iface *hard_iface;
int min_mtu = INT_MAX;
+ batadv_hardif_recalc_headroom(soft_iface);
+
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if ((hard_iface->if_status != BATADV_IF_ACTIVE) &&
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 36b23f31df2a..b4c110791203 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -948,7 +948,7 @@ static void batadv_softif_init_early(struct net_device *dev)
*/
dev->mtu = ETH_DATA_LEN;
/* reserve more space in the skbuff for our header */
- dev->hard_header_len = batadv_max_header_len();
+ dev->hard_header_len = ETH_HLEN + batadv_max_header_len();
/* generate random address */
eth_hw_addr_random(dev);
--
2.5.0
