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authorDavid S. Miller <davem@davemloft.net>2012-10-18 15:36:59 -0400
committerDavid S. Miller <davem@davemloft.net>2012-10-18 15:36:59 -0400
commitdb0fe0b2f6bba2fda939737d063db2ae14c58d71 (patch)
treedc978ed71a75357a5858f6ef84665f9095a65451 /net
parenta3374c42aa5f7237e87ff3b0622018636b0c847e (diff)
parent7dac7b76b8db87fc79857a53a09730fb2148579b (diff)
downloadvexpress-lsk-db0fe0b2f6bba2fda939737d063db2ae14c58d71.tar.gz
Merge tag 'batman-adv-fix-for-davem' of git://git.open-mesh.org/linux-merge
Included fixes: - Fix broadcast packet CRC calculation which can lead to ~80% broadcast packet loss - Fix a race condition in duplicate broadcast packet check Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/batman-adv/bridge_loop_avoidance.c27
-rw-r--r--net/batman-adv/routing.c8
-rw-r--r--net/batman-adv/types.h2
3 files changed, 27 insertions, 10 deletions
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c
index 0a9084ad19a..fd8d5afec0d 100644
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -1167,6 +1167,8 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
uint16_t crc;
unsigned long entrytime;
+ spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
+
batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
/* setting claim destination address */
@@ -1210,8 +1212,8 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
/**
* batadv_bla_check_bcast_duplist
* @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,
@@ -1224,20 +1226,22 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
*/
int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
struct batadv_bcast_packet *bcast_packet,
- int hdr_size)
+ int bcast_packet_len)
{
- int i, length, curr;
+ int i, length, curr, ret = 0;
uint8_t *content;
uint16_t crc;
struct batadv_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);
/* calculate the crc ... */
crc = crc16(0, content, length);
+ spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
+
for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
curr = (bat_priv->bla.bcast_duplist_curr + i);
curr %= BATADV_DUPLIST_SIZE;
@@ -1259,9 +1263,12 @@ int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
/* this entry seems to match: same crc, not too old,
* and from another gw. therefore return 1 to forbid it.
*/
- return 1;
+ ret = 1;
+ goto out;
}
- /* not found, add a new entry (overwrite the oldest entry) */
+ /* not found, add a new entry (overwrite the oldest entry)
+ * and allow it, its the first occurence.
+ */
curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
curr %= BATADV_DUPLIST_SIZE;
entry = &bat_priv->bla.bcast_duplist[curr];
@@ -1270,8 +1277,10 @@ int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
memcpy(entry->orig, bcast_packet->orig, ETH_ALEN);
bat_priv->bla.bcast_duplist_curr = curr;
- /* allow it, its the first occurence. */
- return 0;
+out:
+ spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
+
+ return ret;
}
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 939fc01371d..376b4cc6ca8 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1124,8 +1124,14 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
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 (batadv_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 */
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 2ed82caacdc..ac1e07a8045 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -205,6 +205,8 @@ struct batadv_priv_bla {
struct batadv_hashtable *backbone_hash;
struct batadv_bcast_duplist_entry bcast_duplist[BATADV_DUPLIST_SIZE];
int bcast_duplist_curr;
+ /* protects bcast_duplist and bcast_duplist_curr */
+ spinlock_t bcast_duplist_lock;
struct batadv_bla_claim_dst claim_dest;
struct delayed_work work;
};