[B.A.T.M.A.N.] [PATCH v7 3/5] batman-adv: drop unicast packets from other backbone gw

Sven Eckelmann
2016-09-05T11:20:27Z

From: Andreas Pape <APape@phoenixcontact.com>

Additional dropping of unicast packets received from another backbone gw of
the same backbone network before being forwarded to the same backbone again
is necessary. It was observed in a test setup that in rare cases these
frames lead to looping unicast traffic backbone->mesh->backbone.

Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
Acked-by: Simon Wunderlich <sw@simonwunderlich.de>
[sven@narfation.org: fix conflicts with current version]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
net/batman-adv/routing.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 7e8dc64..03631ee 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -918,14 +918,16 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
struct batadv_unicast_packet *unicast_packet;
struct batadv_unicast_4addr_packet *unicast_4addr_packet;
- u8 *orig_addr;
- struct batadv_orig_node *orig_node = NULL;
+ u8 *orig_addr, *orig_addr_gw;
+ struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL;
int check, hdr_size = sizeof(*unicast_packet);
enum batadv_subtype subtype;
- bool is4addr;
+ bool is4addr, is_gw;
+ struct ethhdr *ethhdr;

unicast_packet = (struct batadv_unicast_packet *)skb->data;
unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
+ ethhdr = eth_hdr(skb);

is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR;
/* the caller function should have already pulled 2 bytes */
@@ -948,6 +950,23 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,

/* packet for me */
if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) {
+ /* If this is a unicast packet from another backgone gw,
+ * drop it.
+ */
+ orig_addr_gw = ethhdr->h_source;
+ orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw);
+ if (orig_node_gw) {
+ is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw,
+ hdr_size);
+ batadv_orig_node_put(orig_node_gw);
+ if (is_gw) {
+ batadv_dbg(BATADV_DBG_BLA, bat_priv,
+ "Dropped unicast pkt received from another backbone gw %pM.\n",
+ orig_addr_gw);
+ return NET_RX_DROP;
+ }
+ }
+
if (is4addr) {
subtype = unicast_4addr_packet->subtype;
batadv_dat_inc_counter(bat_priv, subtype);
--
2.9.3