1 files changed, 54 insertions, 120 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 7c3da29fad8e..36c7f616294a 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -112,53 +112,19 @@ 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)
 {
 	return sk->sk_user_data;
 }
 
-static inline struct l2tp_net *l2tp_pernet(struct net *net)
+static inline struct l2tp_net *l2tp_pernet(const struct net *net)
 {
 	BUG_ON(!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)
-{
-	atomic_inc(&tunnel->ref_count);
-}
-
-static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel)
-{
-	if (atomic_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,			\
-		 atomic_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,			\
-		 atomic_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
@@ -216,27 +182,6 @@ static void l2tp_tunnel_sock_put(struct sock *sk)
 	sock_put(sk);
 }
 
-/* Lookup a session by id in the global session list
- */
-static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id)
-{
-	struct l2tp_net *pn = l2tp_pernet(net);
-	struct hlist_head *session_list =
-		l2tp_session_id_hash_2(pn, session_id);
-	struct l2tp_session *session;
-
-	rcu_read_lock_bh();
-	hlist_for_each_entry_rcu(session, session_list, global_hlist) {
-		if (session->session_id == session_id) {
-			rcu_read_unlock_bh();
-			return session;
-		}
-	}
-	rcu_read_unlock_bh();
-
-	return NULL;
-}
-
 /* Session hash list.
  * The session_id SHOULD be random according to RFC2661, but several
  * L2TP implementations (Cisco and Microsoft) use incrementing
@@ -249,38 +194,31 @@ 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 by id
- */
-struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id)
+/* 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)
 {
-	struct hlist_head *session_list;
-	struct l2tp_session *session;
+	const struct l2tp_net *pn = l2tp_pernet(net);
+	struct l2tp_tunnel *tunnel;
 
-	/* In L2TPv3, session_ids are unique over all tunnels and we
-	 * sometimes need to look them up before we know the
-	 * tunnel.
-	 */
-	if (tunnel == NULL)
-		return l2tp_session_find_2(net, session_id);
+	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();
 
-	session_list = l2tp_session_id_hash(tunnel, session_id);
-	read_lock_bh(&tunnel->hlist_lock);
-	hlist_for_each_entry(session, session_list, hlist) {
-		if (session->session_id == session_id) {
-			read_unlock_bh(&tunnel->hlist_lock);
-			return session;
+			return tunnel;
 		}
 	}
-	read_unlock_bh(&tunnel->hlist_lock);
+	rcu_read_unlock_bh();
 
 	return NULL;
 }
-EXPORT_SYMBOL_GPL(l2tp_session_find);
+EXPORT_SYMBOL_GPL(l2tp_tunnel_get);
 
-/* Like l2tp_session_find() but takes a reference on the returned session.
+/* Lookup a session. A new reference is held on the returned session.
  * Optionally calls session->ref() too if do_ref is true.
  */
-struct l2tp_session *l2tp_session_get(struct net *net,
+struct l2tp_session *l2tp_session_get(const struct net *net,
 				      struct l2tp_tunnel *tunnel,
 				      u32 session_id, bool do_ref)
 {
@@ -355,7 +293,8 @@ EXPORT_SYMBOL_GPL(l2tp_session_get_nth);
 /* Lookup a session by interface name.
  * This is very inefficient but is only used by management interfaces.
  */
-struct l2tp_session *l2tp_session_get_by_ifname(struct net *net, char *ifname,
+struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
+						const char *ifname,
 						bool do_ref)
 {
 	struct l2tp_net *pn = l2tp_pernet(net);
@@ -382,20 +321,28 @@ struct l2tp_session *l2tp_session_get_by_ifname(struct net *net, char *ifname,
 }
 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);
@@ -403,30 +350,44 @@ 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);
 	write_unlock_bh(&tunnel->hlist_lock);
 
+	/* Ignore management session in session count value */
+	if (session->session_id != 0)
+		atomic_inc(&l2tp_session_count);
+
 	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
  */
-struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id)
+struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id)
 {
 	struct l2tp_tunnel *tunnel;
 	struct l2tp_net *pn = l2tp_pernet(net);
@@ -444,7 +405,7 @@ struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id)
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_find);
 
-struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth)
+struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth)
 {
 	struct l2tp_net *pn = l2tp_pernet(net);
 	struct l2tp_tunnel *tunnel;
@@ -1307,7 +1268,6 @@ 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);
@@ -1317,6 +1277,8 @@ static void l2tp_tunnel_destruct(struct sock *sk)
 	atomic_dec(&l2tp_tunnel_count);
 
 	l2tp_tunnel_closeall(tunnel);
+
+	tunnel->sock = NULL;
 	l2tp_tunnel_dec_refcount(tunnel);
 
 	/* Call the original destructor */
@@ -1341,6 +1303,7 @@ 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]) {
@@ -1394,17 +1357,6 @@ 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(atomic_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)
 {
@@ -1655,6 +1607,7 @@ 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;
@@ -1840,7 +1793,6 @@ 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) {
@@ -1895,25 +1847,7 @@ 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.
-		 */
 		l2tp_session_inc_refcount(session);
-		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;
 	}