batman-adv: protect neighbor list with rcu locks

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

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 68b04e7..6cb9af3 100644 (file)
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -67,6 +67,14 @@ void neigh_node_free_ref(struct kref *refcount)
        kfree(neigh_node);
 }
 
+static void neigh_node_free_rcu(struct rcu_head *rcu)
+{
+       struct neigh_node *neigh_node;
+
+       neigh_node = container_of(rcu, struct neigh_node, rcu);
+       kref_put(&neigh_node->refcount, neigh_node_free_ref);
+}
+
 struct neigh_node *create_neighbor(struct orig_node *orig_node,
                                   struct orig_node *orig_neigh_node,
                                   uint8_t *neigh,
@@ -89,7 +97,9 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
        neigh_node->if_incoming = if_incoming;
        kref_init(&neigh_node->refcount);
 
-       hlist_add_head(&neigh_node->list, &orig_node->neigh_list);
+       spin_lock_bh(&orig_node->neigh_list_lock);
+       hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
+       spin_unlock_bh(&orig_node->neigh_list_lock);
        return neigh_node;
 }
 
@@ -100,13 +110,17 @@ static void free_orig_node(void *data, void *arg)
        struct orig_node *orig_node = (struct orig_node *)data;
        struct bat_priv *bat_priv = (struct bat_priv *)arg;
 
+       spin_lock_bh(&orig_node->neigh_list_lock);
+
        /* for all neighbors towards this originator ... */
        hlist_for_each_entry_safe(neigh_node, node, node_tmp,
                                  &orig_node->neigh_list, list) {
-               hlist_del(&neigh_node->list);
-               kref_put(&neigh_node->refcount, neigh_node_free_ref);
+               hlist_del_rcu(&neigh_node->list);
+               call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
        }
 
+       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");
 
@@ -151,6 +165,7 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, uint8_t *addr)
                return NULL;
 
        INIT_HLIST_HEAD(&orig_node->neigh_list);
+       spin_lock_init(&orig_node->neigh_list_lock);
 
        memcpy(orig_node->orig, addr, ETH_ALEN);
        orig_node->router = NULL;
@@ -200,6 +215,8 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,
 
        *best_neigh_node = NULL;
 
+       spin_lock_bh(&orig_node->neigh_list_lock);
+
        /* for all neighbors towards this originator ... */
        hlist_for_each_entry_safe(neigh_node, node, node_tmp,
                                  &orig_node->neigh_list, list) {
@@ -225,14 +242,16 @@ static bool purge_orig_neighbors(struct bat_priv *bat_priv,
 
                        neigh_purged = true;
 
-                       hlist_del(&neigh_node->list);
-                       kref_put(&neigh_node->refcount, neigh_node_free_ref);
+                       hlist_del_rcu(&neigh_node->list);
+                       call_rcu(&neigh_node->rcu, neigh_node_free_rcu);
                } else {
                        if ((!*best_neigh_node) ||
                            (neigh_node->tq_avg > (*best_neigh_node)->tq_avg))
                                *best_neigh_node = neigh_node;
                }
        }
+
+       spin_unlock_bh(&orig_node->neigh_list_lock);
        return neigh_purged;
 }
 
@@ -384,11 +403,13 @@ int orig_seq_print_text(struct seq_file *seq, void *offset)
                                   neigh_node->addr,
                                   neigh_node->if_incoming->net_dev->name);
 
-                       hlist_for_each_entry(neigh_node, node,
-                                            &orig_node->neigh_list, list) {
+                       rcu_read_lock();
+                       hlist_for_each_entry_rcu(neigh_node, node,
+                                                &orig_node->neigh_list, list) {
                                seq_printf(seq, " %pM (%3i)", neigh_node->addr,
                                                neigh_node->tq_avg);
                        }
+                       rcu_read_unlock();
 
                        seq_printf(seq, "\n");
                        batman_count++;

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index e8379ba..97f3216 100644 (file)
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -153,14 +153,16 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
        unsigned char total_count;
 
        if (orig_node == orig_neigh_node) {
-               hlist_for_each_entry(tmp_neigh_node, node,
-                                    &orig_node->neigh_list, list) {
+               rcu_read_lock();
+               hlist_for_each_entry_rcu(tmp_neigh_node, node,
+                                        &orig_node->neigh_list, list) {
 
                        if (compare_orig(tmp_neigh_node->addr,
                                         orig_neigh_node->orig) &&
                            (tmp_neigh_node->if_incoming == if_incoming))
                                neigh_node = tmp_neigh_node;
                }
+               rcu_read_unlock();
 
                if (!neigh_node)
                        neigh_node = create_neighbor(orig_node,
@@ -174,14 +176,16 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
                neigh_node->last_valid = jiffies;
        } else {
                /* find packet count of corresponding one hop neighbor */
-               hlist_for_each_entry(tmp_neigh_node, node,
-                                    &orig_neigh_node->neigh_list, list) {
+               rcu_read_lock();
+               hlist_for_each_entry_rcu(tmp_neigh_node, node,
+                                        &orig_neigh_node->neigh_list, list) {
 
                        if (compare_orig(tmp_neigh_node->addr,
                                         orig_neigh_node->orig) &&
                            (tmp_neigh_node->if_incoming == if_incoming))
                                neigh_node = tmp_neigh_node;
                }
+               rcu_read_unlock();
 
                if (!neigh_node)
                        neigh_node = create_neighbor(orig_neigh_node,
@@ -266,8 +270,9 @@ static void update_orig(struct bat_priv *bat_priv,
        bat_dbg(DBG_BATMAN, bat_priv, "update_originator(): "
                "Searching and updating originator entry of received packet\n");
 
-       hlist_for_each_entry(tmp_neigh_node, node,
-                            &orig_node->neigh_list, list) {
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(tmp_neigh_node, node,
+                                &orig_node->neigh_list, list) {
                if (compare_orig(tmp_neigh_node->addr, ethhdr->h_source) &&
                    (tmp_neigh_node->if_incoming == if_incoming)) {
                        neigh_node = tmp_neigh_node;
@@ -282,6 +287,7 @@ static void update_orig(struct bat_priv *bat_priv,
                tmp_neigh_node->tq_avg =
                        ring_buffer_avg(tmp_neigh_node->tq_recv);
        }
+       rcu_read_unlock();
 
        if (!neigh_node) {
                struct orig_node *orig_tmp;
@@ -410,8 +416,9 @@ static char count_real_packets(struct ethhdr *ethhdr,
                             &orig_node->batman_seqno_reset))
                return -1;
 
-       hlist_for_each_entry(tmp_neigh_node, node,
-                            &orig_node->neigh_list, list) {
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(tmp_neigh_node, node,
+                                &orig_node->neigh_list, list) {
 
                is_duplicate |= get_bit_status(tmp_neigh_node->real_bits,
                                               orig_node->last_real_seqno,
@@ -431,6 +438,7 @@ static char count_real_packets(struct ethhdr *ethhdr,
                tmp_neigh_node->real_packet_count =
                        bit_packet_count(tmp_neigh_node->real_bits);
        }
+       rcu_read_unlock();
 
        if (need_update) {
                bat_dbg(DBG_BATMAN, bat_priv,
@@ -481,15 +489,19 @@ void update_bonding_candidates(struct orig_node *orig_node)
         * as "bonding partner" */
 
        /* first, zero the list */
-       hlist_for_each_entry(tmp_neigh_node, node,
-                            &orig_node->neigh_list, list) {
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(tmp_neigh_node, node,
+                                &orig_node->neigh_list, list) {
                tmp_neigh_node->next_bond_candidate = NULL;
        }
+       rcu_read_unlock();
 
        first_candidate = NULL;
        last_candidate = NULL;
-       hlist_for_each_entry(tmp_neigh_node, node,
-                            &orig_node->neigh_list, list) {
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(tmp_neigh_node, node,
+                                &orig_node->neigh_list, list) {
 
                /* only consider if it has the same primary address ...  */
                if (memcmp(orig_node->orig,
@@ -506,8 +518,8 @@ void update_bonding_candidates(struct orig_node *orig_node)
                 * select this candidate because of possible interference. */
 
                interference_candidate = 0;
-               hlist_for_each_entry(tmp_neigh_node2, node2,
-                                    &orig_node->neigh_list, list) {
+               hlist_for_each_entry_rcu(tmp_neigh_node2, node2,
+                                        &orig_node->neigh_list, list) {
 
                        if (tmp_neigh_node2 == tmp_neigh_node)
                                continue;
@@ -541,6 +553,7 @@ void update_bonding_candidates(struct orig_node *orig_node)
 
                candidates++;
        }
+       rcu_read_unlock();
 
        if (candidates > 0) {
                first_candidate->next_bond_candidate = last_candidate;

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 779c5c3..d4fa727 100644 (file)
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -85,6 +85,7 @@ struct orig_node {
        uint32_t last_bcast_seqno;
        struct hlist_head neigh_list;
        struct list_head frag_list;
+       spinlock_t neigh_list_lock; /* protects neighbor list */
        unsigned long last_frag_packet;
        struct {
                uint8_t candidates;
@@ -116,6 +117,7 @@ struct neigh_node {
        unsigned long last_valid;
        unsigned long real_bits[NUM_WORDS];
        struct kref refcount;
+       struct rcu_head rcu;
        struct orig_node *orig_node;
        struct batman_if *if_incoming;
 };