batman-adv: Fragment and send skbs larger than mtu

Non-broadcast packets larger than MTU are fragmented and sent with
an encapsulating header. Up to 16 fragments are supported, which are
sent in reverse order on the wire to allow minimal memory copying when
creating fragments.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index dd189e6bf05a..18b1fd915d1f 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -442,6 +442,7 @@ static void batadv_softif_destroy_finish(struct work_struct *work)
 static int batadv_softif_init_late(struct net_device *dev)
 {
         struct batadv_priv *bat_priv;
+        uint32_t random_seqno;
         int ret;
         size_t cnt_len = sizeof(uint64_t) * BATADV_CNT_NUM;
 
@@ -491,6 +492,10 @@ static int batadv_softif_init_late(struct net_device *dev)
         bat_priv->tt.last_changeset = NULL;
         bat_priv->tt.last_changeset_len = 0;
 
+        /* randomize initial seqno to avoid collision */
+        get_random_bytes(&random_seqno, sizeof(random_seqno));
+        atomic_set(&bat_priv->frag_seqno, random_seqno);
+
         bat_priv->primary_if = NULL;
         bat_priv->num_ifaces = 0;
 
@@ -758,6 +763,8 @@ static const struct {
         { "mgmt_tx_bytes" },
         { "mgmt_rx" },
         { "mgmt_rx_bytes" },
+        { "frag_tx" },
+        { "frag_tx_bytes" },
         { "frag_rx" },
         { "frag_rx_bytes" },
         { "frag_fwd" },