From: Linus Lüssing <[email protected]>
commit 7f112af40fecf5399b61e69ffc6b55a9d82789f7 upstream.
So far the crc16 checksum for a batman-adv broadcast data packet, received
on a batman-adv hard interface, was calculated over zero bytes of its
content leading to many incoming broadcast data packets wrongly being
dropped (60-80% packet loss).
This patch fixes this issue by calculating the crc16 over the actual,
complete broadcast payload.
The issue is a regression introduced by
("batman-adv: add broadcast duplicate check").
Signed-off-by: Linus Lüssing <[email protected]>
Acked-by: Simon Wunderlich <[email protected]>
Signed-off-by: Marek Lindner <[email protected]>
Signed-off-by: Antonio Quartulli <[email protected]>
---
net/batman-adv/bridge_loop_avoidance.c | 16 +++++++---------
net/batman-adv/routing.c | 8 +++++++-
2 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/net/batman-adv/bridge_loop_avoidance.c
b/net/batman-adv/bridge_loop_avoidance.c
index c5863f4..740bb6f 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -1172,8 +1172,8 @@ int bla_init(struct bat_priv *bat_priv)
/**
* @bat_priv: the bat priv with all the soft interface information
- * @bcast_packet: originator mac address
- * @hdr_size: maximum length of the frame
+ * @bcast_packet: encapsulated broadcast frame plus batman header
+ * @bcast_packet_len: length of encapsulated broadcast frame plus batman header
*
* check if it is on our broadcast list. Another gateway might
* have sent the same packet because it is connected to the same backbone,
@@ -1183,19 +1183,17 @@ int bla_init(struct bat_priv *bat_priv)
* with a good chance that it is the same packet. If it is furthermore
* sent by another host, drop it. We allow equal packets from
* the same host however as this might be intended.
- *
- **/
-
-int bla_check_bcast_duplist(struct bat_priv *bat_priv,
- struct bcast_packet *bcast_packet,
- int hdr_size)
+ */
+int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
+ struct batadv_bcast_packet *bcast_packet,
+ int bcast_packet_len)
{
int i, length, curr;
uint8_t *content;
uint16_t crc;
struct bcast_duplist_entry *entry;
- length = hdr_size - sizeof(*bcast_packet);
+ length = bcast_packet_len - sizeof(*bcast_packet);
content = (uint8_t *)bcast_packet;
content += sizeof(*bcast_packet);
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 015471d..0c2cb6b 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1081,8 +1081,14 @@ int recv_bcast_packet(struct sk_buff *skb, struct
hard_iface *recv_if)
spin_unlock_bh(&orig_node->bcast_seqno_lock);
+ /* keep skb linear for crc calculation */
+ if (skb_linearize(skb) < 0)
+ goto out;
+
+ bcast_packet = (struct batadv_bcast_packet *)skb->data;
+
/* check whether this has been sent by another originator before */
- if (bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
+ if (batadv_bla_check_bcast_duplist(bat_priv, bcast_packet, skb->len))
goto out;
/* rebroadcast packet */
--
1.8.0
