1 files changed, 73 insertions, 131 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index b0c2d4ae781d..115918ad8eca 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -100,8 +100,6 @@ struct l2tp_skb_cb {
 
 #define L2TP_SKB_CB(skb)	((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
 
-static atomic_t l2tp_tunnel_count;
-static atomic_t l2tp_session_count;
 static struct workqueue_struct *l2tp_wq;
 
 /* per-net private data for this module */
@@ -113,7 +111,6 @@ struct l2tp_net {
 	spinlock_t l2tp_session_hlist_lock;
 };
 
-static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
 
 static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk)
 {
@@ -127,39 +124,6 @@ static inline struct l2tp_net *l2tp_pernet(const struct net *net)
 	return net_generic(net, l2tp_net_id);
 }
 
-/* Tunnel reference counts. Incremented per session that is added to
- * the tunnel.
- */
-static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel)
-{
-	refcount_inc(&tunnel->ref_count);
-}
-
-static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel)
-{
-	if (refcount_dec_and_test(&tunnel->ref_count))
-		l2tp_tunnel_free(tunnel);
-}
-#ifdef L2TP_REFCNT_DEBUG
-#define l2tp_tunnel_inc_refcount(_t)					\
-do {									\
-	pr_debug("l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n",	\
-		 __func__, __LINE__, (_t)->name,			\
-		 refcount_read(&_t->ref_count));			\
-	l2tp_tunnel_inc_refcount_1(_t);					\
-} while (0)
-#define l2tp_tunnel_dec_refcount(_t)					\
-do {									\
-	pr_debug("l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n",	\
-		 __func__, __LINE__, (_t)->name,			\
-		 refcount_read(&_t->ref_count));			\
-	l2tp_tunnel_dec_refcount_1(_t);					\
-} while (0)
-#else
-#define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t)
-#define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t)
-#endif
-
 /* Session hash global list for L2TPv3.
  * The session_id SHOULD be random according to RFC3931, but several
  * L2TP implementations use incrementing session_ids.  So we do a real
@@ -229,12 +193,31 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id)
 	return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)];
 }
 
-/* Lookup a session. A new reference is held on the returned session.
- * Optionally calls session->ref() too if do_ref is true.
- */
+/* Lookup a tunnel. A new reference is held on the returned tunnel. */
+struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id)
+{
+	const struct l2tp_net *pn = l2tp_pernet(net);
+	struct l2tp_tunnel *tunnel;
+
+	rcu_read_lock_bh();
+	list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) {
+		if (tunnel->tunnel_id == tunnel_id) {
+			l2tp_tunnel_inc_refcount(tunnel);
+			rcu_read_unlock_bh();
+
+			return tunnel;
+		}
+	}
+	rcu_read_unlock_bh();
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_get);
+
+/* Lookup a session. A new reference is held on the returned session. */
 struct l2tp_session *l2tp_session_get(const struct net *net,
 				      struct l2tp_tunnel *tunnel,
-				      u32 session_id, bool do_ref)
+				      u32 session_id)
 {
 	struct hlist_head *session_list;
 	struct l2tp_session *session;
@@ -248,8 +231,6 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
 		hlist_for_each_entry_rcu(session, session_list, global_hlist) {
 			if (session->session_id == session_id) {
 				l2tp_session_inc_refcount(session);
-				if (do_ref && session->ref)
-					session->ref(session);
 				rcu_read_unlock_bh();
 
 				return session;
@@ -265,8 +246,6 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
 	hlist_for_each_entry(session, session_list, hlist) {
 		if (session->session_id == session_id) {
 			l2tp_session_inc_refcount(session);
-			if (do_ref && session->ref)
-				session->ref(session);
 			read_unlock_bh(&tunnel->hlist_lock);
 
 			return session;
@@ -278,8 +257,7 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
 }
 EXPORT_SYMBOL_GPL(l2tp_session_get);
 
-struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
-					  bool do_ref)
+struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth)
 {
 	int hash;
 	struct l2tp_session *session;
@@ -290,8 +268,6 @@ struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth,
 		hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) {
 			if (++count > nth) {
 				l2tp_session_inc_refcount(session);
-				if (do_ref && session->ref)
-					session->ref(session);
 				read_unlock_bh(&tunnel->hlist_lock);
 				return session;
 			}
@@ -308,8 +284,7 @@ EXPORT_SYMBOL_GPL(l2tp_session_get_nth);
  * This is very inefficient but is only used by management interfaces.
  */
 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
-						const char *ifname,
-						bool do_ref)
+						const char *ifname)
 {
 	struct l2tp_net *pn = l2tp_pernet(net);
 	int hash;
@@ -320,8 +295,6 @@ struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
 		hlist_for_each_entry_rcu(session, &pn->l2tp_session_hlist[hash], global_hlist) {
 			if (!strcmp(session->ifname, ifname)) {
 				l2tp_session_inc_refcount(session);
-				if (do_ref && session->ref)
-					session->ref(session);
 				rcu_read_unlock_bh();
 
 				return session;
@@ -335,20 +308,28 @@ struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
 }
 EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname);
 
-static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel,
-				      struct l2tp_session *session)
+int l2tp_session_register(struct l2tp_session *session,
+			  struct l2tp_tunnel *tunnel)
 {
 	struct l2tp_session *session_walk;
 	struct hlist_head *g_head;
 	struct hlist_head *head;
 	struct l2tp_net *pn;
+	int err;
 
 	head = l2tp_session_id_hash(tunnel, session->session_id);
 
 	write_lock_bh(&tunnel->hlist_lock);
+	if (!tunnel->acpt_newsess) {
+		err = -ENODEV;
+		goto err_tlock;
+	}
+
 	hlist_for_each_entry(session_walk, head, hlist)
-		if (session_walk->session_id == session->session_id)
-			goto exist;
+		if (session_walk->session_id == session->session_id) {
+			err = -EEXIST;
+			goto err_tlock;
+		}
 
 	if (tunnel->version == L2TP_HDR_VER_3) {
 		pn = l2tp_pernet(tunnel->l2tp_net);
@@ -356,12 +337,21 @@ static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel,
 						session->session_id);
 
 		spin_lock_bh(&pn->l2tp_session_hlist_lock);
+
 		hlist_for_each_entry(session_walk, g_head, global_hlist)
-			if (session_walk->session_id == session->session_id)
-				goto exist_glob;
+			if (session_walk->session_id == session->session_id) {
+				err = -EEXIST;
+				goto err_tlock_pnlock;
+			}
 
+		l2tp_tunnel_inc_refcount(tunnel);
+		sock_hold(tunnel->sock);
 		hlist_add_head_rcu(&session->global_hlist, g_head);
+
 		spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+	} else {
+		l2tp_tunnel_inc_refcount(tunnel);
+		sock_hold(tunnel->sock);
 	}
 
 	hlist_add_head(&session->hlist, head);
@@ -369,13 +359,14 @@ static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel,
 
 	return 0;
 
-exist_glob:
+err_tlock_pnlock:
 	spin_unlock_bh(&pn->l2tp_session_hlist_lock);
-exist:
+err_tlock:
 	write_unlock_bh(&tunnel->hlist_lock);
 
-	return -EEXIST;
+	return err;
 }
+EXPORT_SYMBOL_GPL(l2tp_session_register);
 
 /* Lookup a tunnel by id
  */
@@ -480,9 +471,6 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
 		(*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length);
 	else
 		kfree_skb(skb);
-
-	if (session->deref)
-		(*session->deref)(session);
 }
 
 /* Dequeue skbs from the session's reorder_q, subject to packet order.
@@ -511,8 +499,6 @@ start:
 			session->reorder_skip = 1;
 			__skb_unlink(skb, &session->reorder_q);
 			kfree_skb(skb);
-			if (session->deref)
-				(*session->deref)(session);
 			continue;
 		}
 
@@ -685,9 +671,6 @@ discard:
  * a data (not control) frame before coming here. Fields up to the
  * session-id have already been parsed and ptr points to the data
  * after the session-id.
- *
- * session->ref() must have been called prior to l2tp_recv_common().
- * session->deref() will be called automatically after skb is processed.
  */
 void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		      unsigned char *ptr, unsigned char *optr, u16 hdrflags,
@@ -854,9 +837,6 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 discard:
 	atomic_long_inc(&session->stats.rx_errors);
 	kfree_skb(skb);
-
-	if (session->deref)
-		(*session->deref)(session);
 }
 EXPORT_SYMBOL(l2tp_recv_common);
 
@@ -870,8 +850,6 @@ int l2tp_session_queue_purge(struct l2tp_session *session)
 	while ((skb = skb_dequeue(&session->reorder_q))) {
 		atomic_long_inc(&session->stats.rx_errors);
 		kfree_skb(skb);
-		if (session->deref)
-			(*session->deref)(session);
 	}
 	return 0;
 }
@@ -963,13 +941,10 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 	}
 
 	/* Find the session context */
-	session = l2tp_session_get(tunnel->l2tp_net, tunnel, session_id, true);
+	session = l2tp_session_get(tunnel->l2tp_net, tunnel, session_id);
 	if (!session || !session->recv_skb) {
-		if (session) {
-			if (session->deref)
-				session->deref(session);
+		if (session)
 			l2tp_session_dec_refcount(session);
-		}
 
 		/* Not found? Pass to userspace to deal with */
 		l2tp_info(tunnel, L2TP_MSG_DATA,
@@ -1264,16 +1239,14 @@ static void l2tp_tunnel_destruct(struct sock *sk)
 	/* Remove hooks into tunnel socket */
 	sk->sk_destruct = tunnel->old_sk_destruct;
 	sk->sk_user_data = NULL;
-	tunnel->sock = NULL;
 
 	/* Remove the tunnel struct from the tunnel list */
 	pn = l2tp_pernet(tunnel->l2tp_net);
 	spin_lock_bh(&pn->l2tp_tunnel_list_lock);
 	list_del_rcu(&tunnel->list);
 	spin_unlock_bh(&pn->l2tp_tunnel_list_lock);
-	atomic_dec(&l2tp_tunnel_count);
 
-	l2tp_tunnel_closeall(tunnel);
+	tunnel->sock = NULL;
 	l2tp_tunnel_dec_refcount(tunnel);
 
 	/* Call the original destructor */
@@ -1298,6 +1271,7 @@ void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 		  tunnel->name);
 
 	write_lock_bh(&tunnel->hlist_lock);
+	tunnel->acpt_newsess = false;
 	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
 again:
 		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
@@ -1308,8 +1282,8 @@ again:
 
 			hlist_del_init(&session->hlist);
 
-			if (session->ref != NULL)
-				(*session->ref)(session);
+			if (test_and_set_bit(0, &session->dead))
+				goto again;
 
 			write_unlock_bh(&tunnel->hlist_lock);
 
@@ -1319,9 +1293,6 @@ again:
 			if (session->session_close != NULL)
 				(*session->session_close)(session);
 
-			if (session->deref != NULL)
-				(*session->deref)(session);
-
 			l2tp_session_dec_refcount(session);
 
 			write_lock_bh(&tunnel->hlist_lock);
@@ -1348,17 +1319,6 @@ static void l2tp_udp_encap_destroy(struct sock *sk)
 	}
 }
 
-/* Really kill the tunnel.
- * Come here only when all sessions have been cleared from the tunnel.
- */
-static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
-{
-	BUG_ON(refcount_read(&tunnel->ref_count) != 0);
-	BUG_ON(tunnel->sock != NULL);
-	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name);
-	kfree_rcu(tunnel, rcu);
-}
-
 /* Workqueue tunnel deletion function */
 static void l2tp_tunnel_del_work(struct work_struct *work)
 {
@@ -1605,6 +1565,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	tunnel->magic = L2TP_TUNNEL_MAGIC;
 	sprintf(&tunnel->name[0], "tunl %u", tunnel_id);
 	rwlock_init(&tunnel->hlist_lock);
+	tunnel->acpt_newsess = true;
 
 	/* The net we belong to */
 	tunnel->l2tp_net = net;
@@ -1662,7 +1623,6 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 
 	/* Add tunnel to our list */
 	INIT_LIST_HEAD(&tunnel->list);
-	atomic_inc(&l2tp_tunnel_count);
 
 	/* Bump the reference count. The tunnel context is deleted
 	 * only when this drops to zero. Must be done before list insertion
@@ -1689,14 +1649,12 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_create);
 
 /* This function is used by the netlink TUNNEL_DELETE command.
  */
-int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
+void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 {
-	l2tp_tunnel_inc_refcount(tunnel);
-	if (false == queue_work(l2tp_wq, &tunnel->del_work)) {
-		l2tp_tunnel_dec_refcount(tunnel);
-		return 1;
+	if (!test_and_set_bit(0, &tunnel->dead)) {
+		l2tp_tunnel_inc_refcount(tunnel);
+		queue_work(l2tp_wq, &tunnel->del_work);
 	}
-	return 0;
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);
 
@@ -1710,8 +1668,6 @@ void l2tp_session_free(struct l2tp_session *session)
 
 	if (tunnel) {
 		BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
-		if (session->session_id != 0)
-			atomic_dec(&l2tp_session_count);
 		sock_put(tunnel->sock);
 		session->tunnel = NULL;
 		l2tp_tunnel_dec_refcount(tunnel);
@@ -1754,15 +1710,16 @@ EXPORT_SYMBOL_GPL(__l2tp_session_unhash);
  */
 int l2tp_session_delete(struct l2tp_session *session)
 {
-	if (session->ref)
-		(*session->ref)(session);
+	if (test_and_set_bit(0, &session->dead))
+		return 0;
+
 	__l2tp_session_unhash(session);
 	l2tp_session_queue_purge(session);
 	if (session->session_close != NULL)
 		(*session->session_close)(session);
-	if (session->deref)
-		(*session->deref)(session);
+
 	l2tp_session_dec_refcount(session);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(l2tp_session_delete);
@@ -1788,7 +1745,6 @@ EXPORT_SYMBOL_GPL(l2tp_session_set_header_len);
 struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
 {
 	struct l2tp_session *session;
-	int err;
 
 	session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL);
 	if (session != NULL) {
@@ -1844,25 +1800,7 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn
 
 		l2tp_session_set_header_len(session, tunnel->version);
 
-		err = l2tp_session_add_to_tunnel(tunnel, session);
-		if (err) {
-			kfree(session);
-
-			return ERR_PTR(err);
-		}
-
-		/* Bump the reference count. The session context is deleted
-		 * only when this drops to zero.
-		 */
 		refcount_set(&session->ref_count, 1);
-		l2tp_tunnel_inc_refcount(tunnel);
-
-		/* Ensure tunnel socket isn't deleted */
-		sock_hold(tunnel->sock);
-
-		/* Ignore management session in session count value */
-		if (session->session_id != 0)
-			atomic_inc(&l2tp_session_count);
 
 		return session;
 	}
@@ -1895,15 +1833,19 @@ static __net_exit void l2tp_exit_net(struct net *net)
 {
 	struct l2tp_net *pn = l2tp_pernet(net);
 	struct l2tp_tunnel *tunnel = NULL;
+	int hash;
 
 	rcu_read_lock_bh();
 	list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) {
-		(void)l2tp_tunnel_delete(tunnel);
+		l2tp_tunnel_delete(tunnel);
 	}
 	rcu_read_unlock_bh();
 
 	flush_workqueue(l2tp_wq);
 	rcu_barrier();
+
+	for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++)
+		WARN_ON_ONCE(!hlist_empty(&pn->l2tp_session_hlist[hash]));
 }
 
 static struct pernet_operations l2tp_net_ops = {