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);
 }