[B.A.T.M.A.N.] [PATCH 15/28] batman-adv: protect bit operations to count OGMs with spinlock

Sven Eckelmann
2011-03-05T12:28:29Z

Reported-by: Linus Lüssing <linus.luessing@saxnet.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
---
net/batman-adv/routing.c | 61 ++++++++++++++++++++++-----------------------
net/batman-adv/types.h | 6 ++--
2 files changed, 33 insertions(+), 34 deletions(-)

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 9185666..29a689a 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -155,7 +155,8 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
struct hlist_node *node;
unsigned char total_count;
- int ret = 0;
+ uint8_t orig_eq_count, neigh_rq_count, tq_own;
+ int tq_asym_penalty, ret = 0;

if (orig_node == orig_neigh_node) {
rcu_read_lock();
@@ -216,23 +217,25 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,

orig_node->last_valid = jiffies;

+ spin_lock_bh(&orig_node->ogm_cnt_lock);
+ orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
+ neigh_rq_count = neigh_node->real_packet_count;
+ spin_unlock_bh(&orig_node->ogm_cnt_lock);
+
/* pay attention to not get a value bigger than 100 % */
- total_count = (orig_neigh_node->bcast_own_sum[if_incoming->if_num] >
- neigh_node->real_packet_count ?
- neigh_node->real_packet_count :
- orig_neigh_node->bcast_own_sum[if_incoming->if_num]);
+ total_count = (orig_eq_count > neigh_rq_count ?
+ neigh_rq_count : orig_eq_count);

/* if we have too few packets (too less data) we set tq_own to zero */
/* if we receive too few packets it is not considered bidirectional */
if ((total_count < TQ_LOCAL_BIDRECT_SEND_MINIMUM) ||
- (neigh_node->real_packet_count < TQ_LOCAL_BIDRECT_RECV_MINIMUM))
- orig_neigh_node->tq_own = 0;
+ (neigh_rq_count < TQ_LOCAL_BIDRECT_RECV_MINIMUM))
+ tq_own = 0;
else
/* neigh_node->real_packet_count is never zero as we
* only purge old information when getting new
* information */
- orig_neigh_node->tq_own = (TQ_MAX_VALUE * total_count) /
- neigh_node->real_packet_count;
+ tq_own = (TQ_MAX_VALUE * total_count) / neigh_rq_count;

/*
* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
@@ -240,20 +243,16 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
* punishes asymmetric links more. This will give a value
* between 0 and TQ_MAX_VALUE
*/
- orig_neigh_node->tq_asym_penalty =
- TQ_MAX_VALUE -
- (TQ_MAX_VALUE *
- (TQ_LOCAL_WINDOW_SIZE - neigh_node->real_packet_count) *
- (TQ_LOCAL_WINDOW_SIZE - neigh_node->real_packet_count) *
- (TQ_LOCAL_WINDOW_SIZE - neigh_node->real_packet_count)) /
- (TQ_LOCAL_WINDOW_SIZE *
- TQ_LOCAL_WINDOW_SIZE *
- TQ_LOCAL_WINDOW_SIZE);
-
- batman_packet->tq = ((batman_packet->tq *
- orig_neigh_node->tq_own *
- orig_neigh_node->tq_asym_penalty) /
- (TQ_MAX_VALUE * TQ_MAX_VALUE));
+ tq_asym_penalty = TQ_MAX_VALUE - (TQ_MAX_VALUE *
+ (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
+ (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count) *
+ (TQ_LOCAL_WINDOW_SIZE - neigh_rq_count)) /
+ (TQ_LOCAL_WINDOW_SIZE *
+ TQ_LOCAL_WINDOW_SIZE *
+ TQ_LOCAL_WINDOW_SIZE);
+
+ batman_packet->tq = ((batman_packet->tq * tq_own * tq_asym_penalty) /
+ (TQ_MAX_VALUE * TQ_MAX_VALUE));

bat_dbg(DBG_BATMAN, bat_priv,
"bidirectional: "
@@ -261,8 +260,7 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
"real recv = %2i, local tq: %3i, asym_penalty: %3i, "
"total tq: %3i\n",
orig_node->orig, orig_neigh_node->orig, total_count,
- neigh_node->real_packet_count, orig_neigh_node->tq_own,
- orig_neigh_node->tq_asym_penalty, batman_packet->tq);
+ neigh_rq_count, tq_own, tq_asym_penalty, batman_packet->tq);

/* if link has the minimum required transmission quality
* consider it bidirectional */
@@ -559,18 +557,19 @@ static char count_real_packets(struct ethhdr *ethhdr,
char is_duplicate = 0;
int32_t seq_diff;
int need_update = 0;
- int set_mark;
+ int set_mark, ret = -1;

orig_node = get_orig_node(bat_priv, batman_packet->orig);
if (!orig_node)
return 0;

+ spin_lock_bh(&orig_node->ogm_cnt_lock);
seq_diff = batman_packet->seqno - orig_node->last_real_seqno;

/* signalize caller that the packet is to be dropped. */
if (window_protected(bat_priv, seq_diff,
&orig_node->batman_seqno_reset))
- goto err;
+ goto out;

rcu_read_lock();
hlist_for_each_entry_rcu(tmp_neigh_node, node,
@@ -603,12 +602,12 @@ static char count_real_packets(struct ethhdr *ethhdr,
orig_node->last_real_seqno = batman_packet->seqno;
}

- kref_put(&orig_node->refcount, orig_node_free_ref);
- return is_duplicate;
+ ret = is_duplicate;

-err:
+out:
+ spin_unlock_bh(&orig_node->ogm_cnt_lock);
kref_put(&orig_node->refcount, orig_node_free_ref);
- return -1;
+ return ret;
}

void receive_bat_packet(struct ethhdr *ethhdr,
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index e0140c6..9a14276 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -70,8 +70,6 @@ struct orig_node {
struct neigh_node *router;
unsigned long *bcast_own;
uint8_t *bcast_own_sum;
- uint8_t tq_own;
- int tq_asym_penalty;
unsigned long last_valid;
unsigned long bcast_seqno_reset;
unsigned long batman_seqno_reset;
@@ -89,7 +87,9 @@ struct orig_node {
struct kref refcount;
struct bat_priv *bat_priv;
unsigned long last_frag_packet;
- spinlock_t ogm_cnt_lock; /* protects ogm counter */
+ spinlock_t ogm_cnt_lock; /* protects: bcast_own, bcast_own_sum,
+ * neigh_node->real_bits,
+ * neigh_node->real_packet_count */
atomic_t bond_candidates;
struct list_head bond_list;
};
--
1.7.2.3