batman-adv: protect originator nodes with reference counters

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

4 files changed, 78 insertions, 19 deletions

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 5c32314f8279..fcdb0b7fe586 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -103,12 +103,13 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
         return neigh_node;
 }
 
-static void free_orig_node(void *data, void *arg)
+void orig_node_free_ref(struct kref *refcount)
 {
         struct hlist_node *node, *node_tmp;
         struct neigh_node *neigh_node;
-        struct orig_node *orig_node = (struct orig_node *)data;
-        struct bat_priv *bat_priv = (struct bat_priv *)arg;
+        struct orig_node *orig_node;
+
+        orig_node = container_of(refcount, struct orig_node, refcount);
 
         spin_lock_bh(&orig_node->neigh_list_lock);
 
@@ -122,7 +123,8 @@ static void free_orig_node(void *data, void *arg)
         spin_unlock_bh(&orig_node->neigh_list_lock);
 
         frag_list_free(&orig_node->frag_list);
-        hna_global_del_orig(bat_priv, orig_node, "originator timed out");
+        hna_global_del_orig(orig_node->bat_priv, orig_node,
+                            "originator timed out");
 
         kfree(orig_node->bcast_own);
         kfree(orig_node->bcast_own_sum);
@@ -131,17 +133,53 @@ static void free_orig_node(void *data, void *arg)
 
 void originator_free(struct bat_priv *bat_priv)
 {
-        if (!bat_priv->orig_hash)
+        struct hashtable_t *hash = bat_priv->orig_hash;
+        struct hlist_node *walk, *safe;
+        struct hlist_head *head;
+        struct element_t *bucket;
+        spinlock_t *list_lock; /* spinlock to protect write access */
+        struct orig_node *orig_node;
+        int i;
+
+        if (!hash)
                 return;
 
         cancel_delayed_work_sync(&bat_priv->orig_work);
 
         spin_lock_bh(&bat_priv->orig_hash_lock);
-        hash_delete(bat_priv->orig_hash, free_orig_node, bat_priv);
         bat_priv->orig_hash = NULL;
+
+        for (i = 0; i < hash->size; i++) {
+                head = &hash->table[i];
+                list_lock = &hash->list_locks[i];
+
+                spin_lock_bh(list_lock);
+                hlist_for_each_entry_safe(bucket, walk, safe, head, hlist) {
+                        orig_node = bucket->data;
+
+                        hlist_del_rcu(walk);
+                        call_rcu(&bucket->rcu, bucket_free_rcu);
+                        kref_put(&orig_node->refcount, orig_node_free_ref);
+                }
+                spin_unlock_bh(list_lock);
+        }
+
+        hash_destroy(hash);
         spin_unlock_bh(&bat_priv->orig_hash_lock);
 }
 
+static void bucket_free_orig_rcu(struct rcu_head *rcu)
+{
+        struct element_t *bucket;
+        struct orig_node *orig_node;
+
+        bucket = container_of(rcu, struct element_t, rcu);
+        orig_node = bucket->data;
+
+        kref_put(&orig_node->refcount, orig_node_free_ref);
+        kfree(bucket);
+}
+
 /* this function finds or creates an originator entry for the given
  * address if it does not exits */
 struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
@@ -156,8 +194,10 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
                                                    addr));
         rcu_read_unlock();
 
-        if (orig_node)
+        if (orig_node) {
+                kref_get(&orig_node->refcount);
                 return orig_node;
+        }
 
         bat_dbg(DBG_BATMAN, bat_priv,
                 "Creating new originator: %pM\n", addr);
@@ -168,7 +208,9 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
 
         INIT_HLIST_HEAD(&orig_node->neigh_list);
         spin_lock_init(&orig_node->neigh_list_lock);
+        kref_init(&orig_node->refcount);
 
+        orig_node->bat_priv = bat_priv;
         memcpy(orig_node->orig, addr, ETH_ALEN);
         orig_node->router = NULL;
         orig_node->hna_buff = NULL;
@@ -197,6 +239,8 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
         if (hash_added < 0)
                 goto free_bcast_own_sum;
 
+        /* extra reference for return */
+        kref_get(&orig_node->refcount);
         return orig_node;
 free_bcast_own_sum:
         kfree(orig_node->bcast_own_sum);
@@ -318,8 +362,7 @@ static void _purge_orig(struct bat_priv *bat_priv)
                                 if (orig_node->gw_flags)
                                         gw_node_delete(bat_priv, orig_node);
                                 hlist_del_rcu(walk);
-                                call_rcu(&bucket->rcu, bucket_free_rcu);
-                                free_orig_node(orig_node, bat_priv);
+                                call_rcu(&bucket->rcu, bucket_free_orig_rcu);
                                 continue;
                         }
 
diff --git a/net/batman-adv/originator.h b/net/batman-adv/originator.h
index 88e5c6049243..edc64dc33b12 100644
--- a/net/batman-adv/originator.h
+++ b/net/batman-adv/originator.h
@@ -25,6 +25,7 @@
 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);
+void orig_node_free_ref(struct kref *refcount);
 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,
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 32ae04e26a05..1c31a0e9f90a 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -311,6 +311,8 @@ static void update_orig(struct bat_priv *bat_priv,
 
                 neigh_node = create_neighbor(orig_node, orig_tmp,
                                              ethhdr->h_source, if_incoming);
+
+                kref_put(&orig_tmp->refcount, orig_node_free_ref);
                 if (!neigh_node)
                         goto unlock;
         } else
@@ -438,7 +440,7 @@ static char count_real_packets(struct ethhdr *ethhdr,
         /* signalize caller that the packet is to be dropped. */
         if (window_protected(bat_priv, seq_diff,
                              &orig_node->batman_seqno_reset))
-                return -1;
+                goto err;
 
         rcu_read_lock();
         hlist_for_each_entry_rcu(tmp_neigh_node, node,
@@ -471,7 +473,12 @@ 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;
+
+err:
+        kref_put(&orig_node->refcount, orig_node_free_ref);
+        return -1;
 }
 
 /* copy primary address for bonding */
@@ -686,7 +693,6 @@ void receive_bat_packet(struct ethhdr *ethhdr,
                 int offset;
 
                 orig_neigh_node = get_orig_node(bat_priv, ethhdr->h_source);
-
                 if (!orig_neigh_node)
                         return;
 
@@ -707,6 +713,7 @@ void receive_bat_packet(struct ethhdr *ethhdr,
 
                 bat_dbg(DBG_BATMAN, bat_priv, "Drop packet: "
                         "originator packet from myself (via neighbor)\n");
+                kref_put(&orig_neigh_node->refcount, orig_node_free_ref);
                 return;
         }
 
@@ -727,13 +734,13 @@ void receive_bat_packet(struct ethhdr *ethhdr,
                 bat_dbg(DBG_BATMAN, bat_priv,
                         "Drop packet: packet within seqno protection time "
                         "(sender: %pM)\n", ethhdr->h_source);
-                return;
+                goto out;
         }
 
         if (batman_packet->tq == 0) {
                 bat_dbg(DBG_BATMAN, bat_priv,
                         "Drop packet: originator packet with tq equal 0\n");
-                return;
+                goto out;
         }
 
         /* avoid temporary routing loops */
@@ -747,7 +754,7 @@ void receive_bat_packet(struct ethhdr *ethhdr,
                 bat_dbg(DBG_BATMAN, bat_priv,
                         "Drop packet: ignoring all rebroadcast packets that "
                         "may make me loop (sender: %pM)\n", ethhdr->h_source);
-                return;
+                goto out;
         }
 
         /* if sender is a direct neighbor the sender mac equals
@@ -756,14 +763,14 @@ void receive_bat_packet(struct ethhdr *ethhdr,
                            orig_node :
                            get_orig_node(bat_priv, ethhdr->h_source));
         if (!orig_neigh_node)
-                return;
+                goto out_neigh;
 
         /* drop packet if sender is not a direct neighbor and if we
          * don't route towards it */
         if (!is_single_hop_neigh && (!orig_neigh_node->router)) {
                 bat_dbg(DBG_BATMAN, bat_priv,
                         "Drop packet: OGM via unknown neighbor!\n");
-                return;
+                goto out_neigh;
         }
 
         is_bidirectional = is_bidirectional_neigh(orig_node, orig_neigh_node,
@@ -790,26 +797,32 @@ void receive_bat_packet(struct ethhdr *ethhdr,
 
                 bat_dbg(DBG_BATMAN, bat_priv, "Forwarding packet: "
                         "rebroadcast neighbor packet with direct link flag\n");
-                return;
+                goto out_neigh;
         }
 
         /* multihop originator */
         if (!is_bidirectional) {
                 bat_dbg(DBG_BATMAN, bat_priv,
                         "Drop packet: not received via bidirectional link\n");
-                return;
+                goto out_neigh;
         }
 
         if (is_duplicate) {
                 bat_dbg(DBG_BATMAN, bat_priv,
                         "Drop packet: duplicate packet received\n");
-                return;
+                goto out_neigh;
         }
 
         bat_dbg(DBG_BATMAN, bat_priv,
                 "Forwarding packet: rebroadcast originator packet\n");
         schedule_forward_packet(orig_node, ethhdr, batman_packet,
                                 0, hna_buff_len, if_incoming);
+
+out_neigh:
+        if (!is_single_hop_neigh)
+                kref_put(&orig_neigh_node->refcount, orig_node_free_ref);
+out:
+        kref_put(&orig_node->refcount, orig_node_free_ref);
 }
 
 int recv_bat_packet(struct sk_buff *skb, struct batman_if *batman_if)
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index d4fa727aece3..ca4d42d05912 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -86,6 +86,8 @@ struct orig_node {
         struct hlist_head neigh_list;
         struct list_head frag_list;
         spinlock_t neigh_list_lock; /* protects neighbor list */
+        struct kref refcount;
+        struct bat_priv *bat_priv;
         unsigned long last_frag_packet;
         struct {
                 uint8_t candidates;