[B.A.T.M.A.N.] [PATCH 02/28] batman-adv: protect neighbor nodes with reference counters

Sven Eckelmann
2011-03-05T12:28:16Z

net/batman-adv/originator.c | 20 +++++++++++++++-----
net/batman-adv/originator.h | 8 +++++---
net/batman-adv/routing.c | 7 +++++++
net/batman-adv/types.h | 1 +
4 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 54863c9..b1b1773 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -59,9 +59,18 @@ err:
return 0;
}

-struct neigh_node *
-create_neighbor(struct orig_node *orig_node, struct orig_node *orig_neigh_node,
- uint8_t *neigh, struct batman_if *if_incoming)
+void neigh_node_free_ref(struct kref *refcount)
+{
+ struct neigh_node *neigh_node;
+
+ neigh_node = container_of(refcount, struct neigh_node, refcount);
+ kfree(neigh_node);
+}
+
+struct neigh_node *create_neighbor(struct orig_node *orig_node,
+ struct orig_node *orig_neigh_node,
+ uint8_t *neigh,
+ struct batman_if *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
struct neigh_node *neigh_node;
@@ -78,6 +87,7 @@ create_neighbor(struct orig_node *orig_node, struct orig_node *orig_neigh_node,
memcpy(neigh_node->addr, neigh, ETH_ALEN);
neigh_node->orig_node = orig_neigh_node;
neigh_node->if_incoming = if_incoming;
+ kref_init(&neigh_node->refcount);

list_add_tail(&neigh_node->list, &orig_node->neigh_list);
return neigh_node;
@@ -95,7 +105,7 @@ static void free_orig_node(void *data, void *arg)
neigh_node = list_entry(list_pos, struct neigh_node, list);

list_del(list_pos);
- kfree(neigh_node);
+ kref_put(&neigh_node->refcount, neigh_node_free_ref);
}

frag_list_free(&orig_node->frag_list);
@@ -216,7 +226,7 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,

neigh_purged = true;
list_del(list_pos);
- kfree(neigh_node);
+ kref_put(&neigh_node->refcount, neigh_node_free_ref);
} else {
if ((!*best_neigh_node) ||
(neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
diff --git a/net/batman-adv/originator.h b/net/batman-adv/originator.h
index 8019fbd..88e5c60 100644
--- a/net/batman-adv/originator.h
+++ b/net/batman-adv/originator.h
@@ -26,9 +26,11 @@ int originator_init(struct bat_priv *bat_priv);
void originator_free(struct bat_priv *bat_priv);
void purge_orig_ref(struct bat_priv *bat_priv);
struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr);
-struct neigh_node *
-create_neighbor(struct orig_node *orig_node, struct orig_node *orig_neigh_node,
- uint8_t *neigh, struct batman_if *if_incoming);
+struct neigh_node *create_neighbor(struct orig_node *orig_node,
+ struct orig_node *orig_neigh_node,
+ uint8_t *neigh,
+ struct batman_if *if_incoming);
+void neigh_node_free_ref(struct kref *refcount);
int orig_seq_print_text(struct seq_file *seq, void *offset);
int orig_hash_add_if(struct batman_if *batman_if, int max_if_num);
int orig_hash_del_if(struct batman_if *batman_if, int max_if_num);
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 8274140..36351d3 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -89,6 +89,8 @@ static void update_route(struct bat_priv *bat_priv,
struct neigh_node *neigh_node,
unsigned char *hna_buff, int hna_buff_len)
{
+ struct neigh_node *neigh_node_tmp;
+
/* route deleted */
if ((orig_node->router) && (!neigh_node)) {

@@ -115,7 +117,12 @@ static void update_route(struct bat_priv *bat_priv,
orig_node->router->addr);
}

+ if (neigh_node)
+ kref_get(&neigh_node->refcount);
+ neigh_node_tmp = orig_node->router;
orig_node->router = neigh_node;
+ if (neigh_node_tmp)
+ kref_put(&neigh_node_tmp->refcount, neigh_node_free_ref);
}

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 7270405..f9217d5 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -115,6 +115,7 @@ struct neigh_node {
struct neigh_node *next_bond_candidate;
unsigned long last_valid;
unsigned long real_bits[NUM_WORDS];
+ struct kref refcount;
struct orig_node *orig_node;
struct batman_if *if_incoming;
};
--
1.7.2.3