batman-adv: add broadcast duplicate check

When multiple backbone gateways relay the same broadcast from the
backbone into the mesh, other nodes in the mesh may receive this
broadcast multiple times. To avoid this, the crc checksums of
received broadcasts are recorded and new broadcast packets with
the same content may be dropped if received by another gateway.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/batman-adv/bridge_loop_avoidance.h b/net/batman-adv/bridge_loop_avoidance.h
index b74940f09baf..9468c245121c 100644
--- a/net/batman-adv/bridge_loop_avoidance.h
+++ b/net/batman-adv/bridge_loop_avoidance.h
@@ -28,6 +28,8 @@ int bla_is_backbone_gw(struct sk_buff *skb,
                        struct orig_node *orig_node, int hdr_size);
 int bla_claim_table_seq_print_text(struct seq_file *seq, void *offset);
 int bla_is_backbone_gw_orig(struct bat_priv *bat_priv, uint8_t *orig);
+int bla_check_bcast_duplist(struct bat_priv *bat_priv,
+                            struct bcast_packet *bcast_packet, int hdr_size);
 void bla_update_orig_address(struct bat_priv *bat_priv,
                              struct hard_iface *primary_if,
                              struct hard_iface *oldif);