1 files changed, 51 insertions, 19 deletions

diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index 10cdfe2db830..a8dde9b010da 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -498,10 +498,12 @@ static struct sock *__llc_lookup_established(struct llc_sap *sap,
 {
         struct sock *rc;
         struct hlist_nulls_node *node;
+        int slot = llc_sk_laddr_hashfn(sap, laddr);
+        struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
 
         rcu_read_lock();
 again:
-        sk_nulls_for_each_rcu(rc, node, &sap->sk_list) {
+        sk_nulls_for_each_rcu(rc, node, laddr_hb) {
                 if (llc_estab_match(sap, daddr, laddr, rc)) {
                         /* Extra checks required by SLAB_DESTROY_BY_RCU */
                         if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
@@ -515,6 +517,13 @@ again:
                 }
         }
         rc = NULL;
+        /*
+         * if the nulls value we got at the end of this lookup is
+         * not the expected one, we must restart lookup.
+         * We probably met an item that was moved to another chain.
+         */
+        if (unlikely(get_nulls_value(node) != slot))
+                goto again;
 found:
         rcu_read_unlock();
         return rc;
@@ -540,29 +549,20 @@ static inline bool llc_listener_match(const struct llc_sap *sap,
 
         return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
                 llc->laddr.lsap == laddr->lsap &&
-                (llc_mac_match(llc->laddr.mac, laddr->mac) ||
-                 llc_mac_null(llc->laddr.mac));
+                llc_mac_match(llc->laddr.mac, laddr->mac);
 }
 
-/**
- *      llc_lookup_listener - Finds listener for local MAC + SAP
- *      @sap: SAP
- *      @laddr: address of local LLC (MAC + SAP)
- *
- *      Search connection list of the SAP and finds connection listening on
- *      local mac, and local sap. Returns pointer for parent socket found,
- *      %NULL otherwise.
- *      Caller has to make sure local_bh is disabled.
- */
-static struct sock *llc_lookup_listener(struct llc_sap *sap,
-                                        struct llc_addr *laddr)
+static struct sock *__llc_lookup_listener(struct llc_sap *sap,
+                                          struct llc_addr *laddr)
 {
         struct sock *rc;
         struct hlist_nulls_node *node;
+        int slot = llc_sk_laddr_hashfn(sap, laddr);
+        struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
 
         rcu_read_lock();
 again:
-        sk_nulls_for_each_rcu(rc, node, &sap->sk_list) {
+        sk_nulls_for_each_rcu(rc, node, laddr_hb) {
                 if (llc_listener_match(sap, laddr, rc)) {
                         /* Extra checks required by SLAB_DESTROY_BY_RCU */
                         if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
@@ -576,11 +576,40 @@ again:
                 }
         }
         rc = NULL;
+        /*
+         * if the nulls value we got at the end of this lookup is
+         * not the expected one, we must restart lookup.
+         * We probably met an item that was moved to another chain.
+         */
+        if (unlikely(get_nulls_value(node) != slot))
+                goto again;
 found:
         rcu_read_unlock();
         return rc;
 }
 
+/**
+ *      llc_lookup_listener - Finds listener for local MAC + SAP
+ *      @sap: SAP
+ *      @laddr: address of local LLC (MAC + SAP)
+ *
+ *      Search connection list of the SAP and finds connection listening on
+ *      local mac, and local sap. Returns pointer for parent socket found,
+ *      %NULL otherwise.
+ *      Caller has to make sure local_bh is disabled.
+ */
+static struct sock *llc_lookup_listener(struct llc_sap *sap,
+                                        struct llc_addr *laddr)
+{
+        static struct llc_addr null_addr;
+        struct sock *rc = __llc_lookup_listener(sap, laddr);
+
+        if (!rc)
+                rc = __llc_lookup_listener(sap, &null_addr);
+
+        return rc;
+}
+
 static struct sock *__llc_lookup(struct llc_sap *sap,
                                  struct llc_addr *daddr,
                                  struct llc_addr *laddr)
@@ -678,18 +707,20 @@ static int llc_find_offset(int state, int ev_type)
  *      @sap: SAP
  *      @sk: socket
  *
- *      This function adds a socket to sk_list of a SAP.
+ *      This function adds a socket to the hash tables of a SAP.
  */
 void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
 {
         struct llc_sock *llc = llc_sk(sk);
         struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex);
+        struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr);
 
         llc_sap_hold(sap);
         llc_sk(sk)->sap = sap;
 
         spin_lock_bh(&sap->sk_lock);
-        sk_nulls_add_node_rcu(sk, &sap->sk_list);
+        sap->sk_count++;
+        sk_nulls_add_node_rcu(sk, laddr_hb);
         hlist_add_head(&llc->dev_hash_node, dev_hb);
         spin_unlock_bh(&sap->sk_lock);
 }
@@ -699,7 +730,7 @@ void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
  *      @sap: SAP
  *      @sk: socket
  *
- *      This function removes a connection from sk_list of a SAP if
+ *      This function removes a connection from the hash tables of a SAP if
  *      the connection was in this list.
  */
 void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
@@ -709,6 +740,7 @@ void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
         spin_lock_bh(&sap->sk_lock);
         sk_nulls_del_node_init_rcu(sk);
         hlist_del(&llc->dev_hash_node);
+        sap->sk_count--;
         spin_unlock_bh(&sap->sk_lock);
         llc_sap_put(sap);
 }