iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Included fixes:

Browse Source 
- Fix broadcast packet CRC calculation which can lead to ~80% broadcast packet
   loss
 - Fix a race condition in duplicate broadcast packet check
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iEYEABECAAYFAlCANjIACgkQpGgxIkP9cwfeUwCgkGfv2Y8evZYX6d1bW2kFg7di
 LJ8AoISKwbTCJUvKrUuQHAvTss7bcX4k
 =/dxF
 -----END PGP SIGNATURE-----

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>
This commit is contained in:
David S. Miller 2012-10-18 15:36:59 -04:00
commit db0fe0b2f6
3 changed files with 27 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
net/batman-adv/bridge_loop_avoidance.c
View File

@ -1167,6 +1167,8 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
uint16_t crc; uint16_t crc;
unsigned long entrytime; unsigned long entrytime;
spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n"); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
/* setting claim destination address */ /* setting claim destination address */
@ -1210,8 +1212,8 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
/** /**
* batadv_bla_check_bcast_duplist * batadv_bla_check_bcast_duplist
* @bat_priv: the bat priv with all the soft interface information * @bat_priv: the bat priv with all the soft interface information
* @bcast_packet: originator mac address * @bcast_packet: encapsulated broadcast frame plus batman header
* @hdr_size: maximum length of the frame * @bcast_packet_len: length of encapsulated broadcast frame plus batman header
* *
* check if it is on our broadcast list. Another gateway might * check if it is on our broadcast list. Another gateway might
* have sent the same packet because it is connected to the same backbone, * 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, int batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
struct batadv_bcast_packet *bcast_packet, 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; uint8_t *content;
uint16_t crc; uint16_t crc;
struct batadv_bcast_duplist_entry *entry; 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 = (uint8_t *)bcast_packet;
content += sizeof(*bcast_packet); content += sizeof(*bcast_packet);
/* calculate the crc ... */ /* calculate the crc ... */
crc = crc16(0, content, length); crc = crc16(0, content, length);
spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
for (i = 0; i < BATADV_DUPLIST_SIZE; i++) { for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
curr = (bat_priv->bla.bcast_duplist_curr + i); curr = (bat_priv->bla.bcast_duplist_curr + i);
curr %= BATADV_DUPLIST_SIZE; 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, /* this entry seems to match: same crc, not too old,
* and from another gw. therefore return 1 to forbid it. * 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 = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
curr %= BATADV_DUPLIST_SIZE; curr %= BATADV_DUPLIST_SIZE;
entry = &bat_priv->bla.bcast_duplist[curr]; 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); memcpy(entry->orig, bcast_packet->orig, ETH_ALEN);
bat_priv->bla.bcast_duplist_curr = curr; bat_priv->bla.bcast_duplist_curr = curr;
/* allow it, its the first occurence. */ out:
return 0; spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock);
return ret;
} }

8
net/batman-adv/routing.c
View File

@ -1124,8 +1124,14 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
spin_unlock_bh(&orig_node->bcast_seqno_lock); 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 */ /* 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; goto out;
/* rebroadcast packet */ /* rebroadcast packet */

2
net/batman-adv/types.h
View File

@ -205,6 +205,8 @@ struct batadv_priv_bla {
struct batadv_hashtable *backbone_hash; struct batadv_hashtable *backbone_hash;
struct batadv_bcast_duplist_entry bcast_duplist[BATADV_DUPLIST_SIZE]; struct batadv_bcast_duplist_entry bcast_duplist[BATADV_DUPLIST_SIZE];
int bcast_duplist_curr; int bcast_duplist_curr;
/* protects bcast_duplist and bcast_duplist_curr */
spinlock_t bcast_duplist_lock;
struct batadv_bla_claim_dst claim_dest; struct batadv_bla_claim_dst claim_dest;
struct delayed_work work; struct delayed_work work;
}; };