--- zzzz-none-000/linux-4.1.52/net/l2tp/l2tp_ppp.c	2018-05-28 02:26:45.000000000 +0000
+++ bcm63-7530ax-731/linux-4.1.52/net/l2tp/l2tp_ppp.c	2022-03-02 11:37:13.000000000 +0000
@@ -122,8 +122,11 @@
 struct pppol2tp_session {
 	int			owner;		/* pid that opened the socket */
 
-	struct sock		*sock;		/* Pointer to the session
+	struct mutex		sk_lock;	/* Protects .sk */
+	struct sock __rcu	*sk;		/* Pointer to the session
 						 * PPPoX socket */
+	struct sock		*__sk;		/* Copy of .sk, for cleanup */
+	struct rcu_head		rcu;		/* For asynchronous release */
 	struct sock		*tunnel_sock;	/* Pointer to the tunnel UDP
 						 * socket */
 	int			flags;		/* accessed by PPPIOCGFLAGS.
@@ -138,6 +141,24 @@
 
 static const struct proto_ops pppol2tp_ops;
 
+/* Retrieves the pppol2tp socket associated to a session.
+ * A reference is held on the returned socket, so this function must be paired
+ * with sock_put().
+ */
+static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session)
+{
+	struct pppol2tp_session *ps = l2tp_session_priv(session);
+	struct sock *sk;
+
+	rcu_read_lock();
+	sk = rcu_dereference(ps->sk);
+	if (sk)
+		sock_hold(sk);
+	rcu_read_unlock();
+
+	return sk;
+}
+
 /* Helpers to obtain tunnel/session contexts from sockets.
  */
 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk)
@@ -177,7 +198,7 @@
 	if (!pskb_may_pull(skb, 2))
 		return 1;
 
-	if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03))
+	if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI))
 		skb_pull(skb, 2);
 
 	return 0;
@@ -224,13 +245,14 @@
 	/* If the socket is bound, send it in to PPP's input queue. Otherwise
 	 * queue it on the session socket.
 	 */
-	sk = ps->sock;
+	rcu_read_lock();
+	sk = rcu_dereference(ps->sk);
 	if (sk == NULL)
 		goto no_sock;
 
 	if (sk->sk_state & PPPOX_BOUND) {
 		struct pppox_sock *po;
-		l2tp_dbg(session, PPPOL2TP_MSG_DATA,
+		l2tp_dbg(session, L2TP_MSG_DATA,
 			 "%s: recv %d byte data frame, passing to ppp\n",
 			 session->name, data_len);
 
@@ -253,7 +275,7 @@
 		po = pppox_sk(sk);
 		ppp_input(&po->chan, skb);
 	} else {
-		l2tp_dbg(session, PPPOL2TP_MSG_DATA,
+		l2tp_dbg(session, L2TP_MSG_DATA,
 			 "%s: recv %d byte data frame, passing to L2TP socket\n",
 			 session->name, data_len);
 
@@ -262,30 +284,16 @@
 			kfree_skb(skb);
 		}
 	}
+	rcu_read_unlock();
 
 	return;
 
 no_sock:
-	l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: no socket\n", session->name);
+	rcu_read_unlock();
+	l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
 	kfree_skb(skb);
 }
 
-static void pppol2tp_session_sock_hold(struct l2tp_session *session)
-{
-	struct pppol2tp_session *ps = l2tp_session_priv(session);
-
-	if (ps->sock)
-		sock_hold(ps->sock);
-}
-
-static void pppol2tp_session_sock_put(struct l2tp_session *session)
-{
-	struct pppol2tp_session *ps = l2tp_session_priv(session);
-
-	if (ps->sock)
-		sock_put(ps->sock);
-}
-
 /************************************************************************
  * Transmit handling
  ***********************************************************************/
@@ -297,7 +305,6 @@
 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m,
 			    size_t total_len)
 {
-	static const unsigned char ppph[2] = { 0xff, 0x03 };
 	struct sock *sk = sock->sk;
 	struct sk_buff *skb;
 	int error;
@@ -327,7 +334,7 @@
 	error = -ENOMEM;
 	skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) +
 			   uhlen + session->hdr_len +
-			   sizeof(ppph) + total_len,
+			   2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
 			   0, GFP_KERNEL);
 	if (!skb)
 		goto error_put_sess_tun;
@@ -340,8 +347,8 @@
 	skb_reserve(skb, uhlen);
 
 	/* Add PPP header */
-	skb->data[0] = ppph[0];
-	skb->data[1] = ppph[1];
+	skb->data[0] = PPP_ALLSTATIONS;
+	skb->data[1] = PPP_UI;
 	skb_put(skb, 2);
 
 	/* Copy user data into skb */
@@ -384,7 +391,6 @@
  */
 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 {
-	static const u8 ppph[2] = { 0xff, 0x03 };
 	struct sock *sk = (struct sock *) chan->private;
 	struct sock *sk_tun;
 	struct l2tp_session *session;
@@ -413,14 +419,14 @@
 		   sizeof(struct iphdr) + /* IP header */
 		   uhlen +		/* UDP header (if L2TP_ENCAPTYPE_UDP) */
 		   session->hdr_len +	/* L2TP header */
-		   sizeof(ppph);	/* PPP header */
+		   2;			/* 2 bytes for PPP_ALLSTATIONS & PPP_UI */
 	if (skb_cow_head(skb, headroom))
 		goto abort_put_sess_tun;
 
 	/* Setup PPP header */
-	__skb_push(skb, sizeof(ppph));
-	skb->data[0] = ppph[0];
-	skb->data[1] = ppph[1];
+	__skb_push(skb, 2);
+	skb->data[0] = PPP_ALLSTATIONS;
+	skb->data[1] = PPP_UI;
 
 	local_bh_disable();
 	l2tp_xmit_skb(session, skb, session->hdr_len);
@@ -448,16 +454,15 @@
  */
 static void pppol2tp_session_close(struct l2tp_session *session)
 {
-	struct pppol2tp_session *ps = l2tp_session_priv(session);
-	struct sock *sk = ps->sock;
-	struct socket *sock = sk->sk_socket;
+	struct sock *sk;
 
 	BUG_ON(session->magic != L2TP_SESSION_MAGIC);
 
-	if (sock) {
-		inet_shutdown(sock, 2);
-		/* Don't let the session go away before our socket does */
-		l2tp_session_inc_refcount(session);
+	sk = pppol2tp_session_get_sock(session);
+	if (sk) {
+		if (sk->sk_socket)
+			inet_shutdown(sk->sk_socket, SEND_SHUTDOWN);
+		sock_put(sk);
 	}
 }
 
@@ -478,6 +483,14 @@
 	}
 }
 
+static void pppol2tp_put_sk(struct rcu_head *head)
+{
+	struct pppol2tp_session *ps;
+
+	ps = container_of(head, typeof(*ps), rcu);
+	sock_put(ps->__sk);
+}
+
 /* Called when the PPPoX socket (session) is closed.
  */
 static int pppol2tp_release(struct socket *sock)
@@ -503,11 +516,23 @@
 
 	session = pppol2tp_sock_to_session(sk);
 
-	/* Purge any queued data */
 	if (session != NULL) {
-		__l2tp_session_unhash(session);
-		l2tp_session_queue_purge(session);
-		sock_put(sk);
+		struct pppol2tp_session *ps;
+
+		l2tp_session_delete(session);
+
+		ps = l2tp_session_priv(session);
+		mutex_lock(&ps->sk_lock);
+		ps->__sk = rcu_dereference_protected(ps->sk,
+						     lockdep_is_held(&ps->sk_lock));
+		RCU_INIT_POINTER(ps->sk, NULL);
+		mutex_unlock(&ps->sk_lock);
+		call_rcu(&ps->rcu, pppol2tp_put_sk);
+
+		/* Rely on the sock_put() call at the end of the function for
+		 * dropping the reference held by pppol2tp_sock_to_session().
+		 * The last reference will be dropped by pppol2tp_put_sk().
+		 */
 	}
 	release_sock(sk);
 
@@ -574,16 +599,47 @@
 static void pppol2tp_show(struct seq_file *m, void *arg)
 {
 	struct l2tp_session *session = arg;
-	struct pppol2tp_session *ps = l2tp_session_priv(session);
+	struct sock *sk;
+
+	sk = pppol2tp_session_get_sock(session);
+	if (sk) {
+		struct pppox_sock *po = pppox_sk(sk);
 
-	if (ps) {
-		struct pppox_sock *po = pppox_sk(ps->sock);
-		if (po)
-			seq_printf(m, "   interface %s\n", ppp_dev_name(&po->chan));
+		seq_printf(m, "   interface %s\n", ppp_dev_name(&po->chan));
+		sock_put(sk);
 	}
 }
 #endif
 
+static void pppol2tp_session_init(struct l2tp_session *session)
+{
+	struct pppol2tp_session *ps;
+	struct dst_entry *dst;
+
+	session->recv_skb = pppol2tp_recv;
+	session->session_close = pppol2tp_session_close;
+#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
+	session->show = pppol2tp_show;
+#endif
+
+	ps = l2tp_session_priv(session);
+	mutex_init(&ps->sk_lock);
+	ps->tunnel_sock = session->tunnel->sock;
+	ps->owner = current->pid;
+
+	/* If PMTU discovery was enabled, use the MTU that was discovered */
+	dst = sk_dst_get(session->tunnel->sock);
+	if (dst) {
+		u32 pmtu = dst_mtu(dst);
+
+		if (pmtu) {
+			session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD;
+			session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD;
+		}
+		dst_release(dst);
+	}
+}
+
 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket
  */
 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
@@ -595,11 +651,11 @@
 	struct l2tp_session *session = NULL;
 	struct l2tp_tunnel *tunnel;
 	struct pppol2tp_session *ps;
-	struct dst_entry *dst;
 	struct l2tp_session_cfg cfg = { 0, };
 	int error = 0;
 	u32 tunnel_id, peer_tunnel_id;
 	u32 session_id, peer_session_id;
+	bool drop_refcnt = false;
 	int ver = 2;
 	int fd;
 
@@ -708,65 +764,53 @@
 	if (tunnel->peer_tunnel_id == 0)
 		tunnel->peer_tunnel_id = peer_tunnel_id;
 
-	/* Create session if it doesn't already exist. We handle the
-	 * case where a session was previously created by the netlink
-	 * interface by checking that the session doesn't already have
-	 * a socket and its tunnel socket are what we expect. If any
-	 * of those checks fail, return EEXIST to the caller.
-	 */
-	session = l2tp_session_find(sock_net(sk), tunnel, session_id);
-	if (session == NULL) {
-		/* Default MTU must allow space for UDP/L2TP/PPP
-		 * headers.
+	session = l2tp_session_get(sock_net(sk), tunnel, session_id, false);
+	if (session) {
+		drop_refcnt = true;
+		ps = l2tp_session_priv(session);
+
+		/* Using a pre-existing session is fine as long as it hasn't
+		 * been connected yet.
 		 */
-		cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
+		mutex_lock(&ps->sk_lock);
+		if (rcu_dereference_protected(ps->sk,
+					      lockdep_is_held(&ps->sk_lock))) {
+			mutex_unlock(&ps->sk_lock);
+			error = -EEXIST;
+			goto end;
+		}
+
+		/* consistency checks */
+		if (ps->tunnel_sock != tunnel->sock) {
+			mutex_unlock(&ps->sk_lock);
+			error = -EEXIST;
+			goto end;
+		}
+	} else {
+		/* Default MTU must allow space for UDP/L2TP/PPP headers */
+		cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD;
+		cfg.mru = cfg.mtu;
 
-		/* Allocate and initialize a new session context. */
 		session = l2tp_session_create(sizeof(struct pppol2tp_session),
 					      tunnel, session_id,
 					      peer_session_id, &cfg);
-		if (session == NULL) {
-			error = -ENOMEM;
+		if (IS_ERR(session)) {
+			error = PTR_ERR(session);
 			goto end;
 		}
-	} else {
+
+		pppol2tp_session_init(session);
 		ps = l2tp_session_priv(session);
-		error = -EEXIST;
-		if (ps->sock != NULL)
-			goto end;
+		l2tp_session_inc_refcount(session);
 
-		/* consistency checks */
-		if (ps->tunnel_sock != tunnel->sock)
+		mutex_lock(&ps->sk_lock);
+		error = l2tp_session_register(session, tunnel);
+		if (error < 0) {
+			mutex_unlock(&ps->sk_lock);
+			kfree(session);
 			goto end;
-	}
-
-	/* Associate session with its PPPoL2TP socket */
-	ps = l2tp_session_priv(session);
-	ps->owner	     = current->pid;
-	ps->sock	     = sk;
-	ps->tunnel_sock = tunnel->sock;
-
-	session->recv_skb	= pppol2tp_recv;
-	session->session_close	= pppol2tp_session_close;
-#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE)
-	session->show		= pppol2tp_show;
-#endif
-
-	/* We need to know each time a skb is dropped from the reorder
-	 * queue.
-	 */
-	session->ref = pppol2tp_session_sock_hold;
-	session->deref = pppol2tp_session_sock_put;
-
-	/* If PMTU discovery was enabled, use the MTU that was discovered */
-	dst = sk_dst_get(tunnel->sock);
-	if (dst != NULL) {
-		u32 pmtu = dst_mtu(dst);
-
-		if (pmtu != 0)
-			session->mtu = session->mru = pmtu -
-				PPPOL2TP_HEADER_OVERHEAD;
-		dst_release(dst);
+		}
+		drop_refcnt = true;
 	}
 
 	/* Special case: if source & dest session_id == 0x0000, this
@@ -791,17 +835,30 @@
 	po->chan.mtu	 = session->mtu;
 
 	error = ppp_register_net_channel(sock_net(sk), &po->chan);
-	if (error)
+	if (error) {
+		mutex_unlock(&ps->sk_lock);
 		goto end;
+	}
 
 out_no_ppp:
 	/* This is how we get the session context from the socket. */
 	sk->sk_user_data = session;
+	rcu_assign_pointer(ps->sk, sk);
+	mutex_unlock(&ps->sk_lock);
+
+	/* Keep the reference we've grabbed on the session: sk doesn't expect
+	 * the session to disappear. pppol2tp_session_destruct() is responsible
+	 * for dropping it.
+	 */
+	drop_refcnt = false;
+
 	sk->sk_state = PPPOX_CONNECTED;
-	l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
+	l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
 		  session->name);
 
 end:
+	if (drop_refcnt)
+		l2tp_session_dec_refcount(session);
 	release_sock(sk);
 
 	return error;
@@ -809,31 +866,19 @@
 
 #ifdef CONFIG_L2TP_V3
 
-/* Called when creating sessions via the netlink interface.
- */
-static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg)
+/* Called when creating sessions via the netlink interface. */
+static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel,
+				   u32 session_id, u32 peer_session_id,
+				   struct l2tp_session_cfg *cfg)
 {
 	int error;
-	struct l2tp_tunnel *tunnel;
 	struct l2tp_session *session;
-	struct pppol2tp_session *ps;
-
-	tunnel = l2tp_tunnel_find(net, tunnel_id);
-
-	/* Error if we can't find the tunnel */
-	error = -ENOENT;
-	if (tunnel == NULL)
-		goto out;
 
 	/* Error if tunnel socket is not prepped */
-	if (tunnel->sock == NULL)
-		goto out;
-
-	/* Check that this session doesn't already exist */
-	error = -EEXIST;
-	session = l2tp_session_find(net, tunnel, session_id);
-	if (session != NULL)
-		goto out;
+	if (!tunnel->sock) {
+		error = -ENOENT;
+		goto err;
+	}
 
 	/* Default MTU values. */
 	if (cfg->mtu == 0)
@@ -842,22 +887,25 @@
 		cfg->mru = cfg->mtu;
 
 	/* Allocate and initialize a new session context. */
-	error = -ENOMEM;
 	session = l2tp_session_create(sizeof(struct pppol2tp_session),
 				      tunnel, session_id,
 				      peer_session_id, cfg);
-	if (session == NULL)
-		goto out;
+	if (IS_ERR(session)) {
+		error = PTR_ERR(session);
+		goto err;
+	}
 
-	ps = l2tp_session_priv(session);
-	ps->tunnel_sock = tunnel->sock;
+	pppol2tp_session_init(session);
 
-	l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n",
-		  session->name);
+	error = l2tp_session_register(session, tunnel);
+	if (error < 0)
+		goto err_sess;
 
-	error = 0;
+	return 0;
 
-out:
+err_sess:
+	kfree(session);
+err:
 	return error;
 }
 
@@ -889,10 +937,8 @@
 
 	pls = l2tp_session_priv(session);
 	tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock);
-	if (tunnel == NULL) {
-		error = -EBADF;
+	if (tunnel == NULL)
 		goto end_put_sess;
-	}
 
 	inet = inet_sk(tunnel->sock);
 	if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) {
@@ -970,12 +1016,11 @@
 	}
 
 	*usockaddr_len = len;
+	error = 0;
 
 	sock_put(pls->tunnel_sock);
 end_put_sess:
 	sock_put(sk);
-	error = 0;
-
 end:
 	return error;
 }
@@ -1017,16 +1062,14 @@
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	struct pppol2tp_ioc_stats stats;
 
-	l2tp_dbg(session, PPPOL2TP_MSG_CONTROL,
+	l2tp_dbg(session, L2TP_MSG_CONTROL,
 		 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n",
 		 session->name, cmd, arg);
 
-	sk = ps->sock;
+	sk = pppol2tp_session_get_sock(session);
 	if (!sk)
 		return -EBADR;
 
-	sock_hold(sk);
-
 	switch (cmd) {
 	case SIOCGIFMTU:
 		err = -ENXIO;
@@ -1040,7 +1083,7 @@
 		if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq)))
 			break;
 
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n",
 			  session->name, session->mtu);
 		err = 0;
 		break;
@@ -1056,7 +1099,7 @@
 
 		session->mtu = ifr.ifr_mtu;
 
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n",
 			  session->name, session->mtu);
 		err = 0;
 		break;
@@ -1070,7 +1113,7 @@
 		if (put_user(session->mru, (int __user *) arg))
 			break;
 
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n",
 			  session->name, session->mru);
 		err = 0;
 		break;
@@ -1085,7 +1128,7 @@
 			break;
 
 		session->mru = val;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n",
 			  session->name, session->mru);
 		err = 0;
 		break;
@@ -1095,7 +1138,7 @@
 		if (put_user(ps->flags, (int __user *) arg))
 			break;
 
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n",
 			  session->name, ps->flags);
 		err = 0;
 		break;
@@ -1105,7 +1148,7 @@
 		if (get_user(val, (int __user *) arg))
 			break;
 		ps->flags = val;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n",
 			  session->name, ps->flags);
 		err = 0;
 		break;
@@ -1122,7 +1165,7 @@
 		if (copy_to_user((void __user *) arg, &stats,
 				 sizeof(stats)))
 			break;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
 			  session->name);
 		err = 0;
 		break;
@@ -1150,7 +1193,7 @@
 	struct sock *sk;
 	struct pppol2tp_ioc_stats stats;
 
-	l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL,
+	l2tp_dbg(tunnel, L2TP_MSG_CONTROL,
 		 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n",
 		 tunnel->name, cmd, arg);
 
@@ -1171,11 +1214,18 @@
 		if (stats.session_id != 0) {
 			/* resend to session ioctl handler */
 			struct l2tp_session *session =
-				l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
-			if (session != NULL)
-				err = pppol2tp_session_ioctl(session, cmd, arg);
-			else
+				l2tp_session_get(sock_net(sk), tunnel,
+						 stats.session_id, true);
+
+			if (session) {
+				err = pppol2tp_session_ioctl(session, cmd,
+							     arg);
+				if (session->deref)
+					session->deref(session);
+				l2tp_session_dec_refcount(session);
+			} else {
 				err = -EBADR;
+			}
 			break;
 		}
 #ifdef CONFIG_XFRM
@@ -1186,7 +1236,7 @@
 			err = -EFAULT;
 			break;
 		}
-		l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n",
+		l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n",
 			  tunnel->name);
 		err = 0;
 		break;
@@ -1276,7 +1326,7 @@
 	switch (optname) {
 	case PPPOL2TP_SO_DEBUG:
 		tunnel->debug = val;
-		l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
+		l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
 			  tunnel->name, tunnel->debug);
 		break;
 
@@ -1295,7 +1345,6 @@
 				       int optname, int val)
 {
 	int err = 0;
-	struct pppol2tp_session *ps = l2tp_session_priv(session);
 
 	switch (optname) {
 	case PPPOL2TP_SO_RECVSEQ:
@@ -1304,7 +1353,7 @@
 			break;
 		}
 		session->recv_seq = val ? -1 : 0;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: set recv_seq=%d\n",
 			  session->name, session->recv_seq);
 		break;
@@ -1316,13 +1365,13 @@
 		}
 		session->send_seq = val ? -1 : 0;
 		{
-			struct sock *ssk      = ps->sock;
-			struct pppox_sock *po = pppox_sk(ssk);
+			struct pppox_sock *po = pppox_sk(sk);
+
 			po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ :
 				PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
 		}
 		l2tp_session_set_header_len(session, session->tunnel->version);
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: set send_seq=%d\n",
 			  session->name, session->send_seq);
 		break;
@@ -1333,20 +1382,20 @@
 			break;
 		}
 		session->lns_mode = val ? -1 : 0;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: set lns_mode=%d\n",
 			  session->name, session->lns_mode);
 		break;
 
 	case PPPOL2TP_SO_DEBUG:
 		session->debug = val;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
 			  session->name, session->debug);
 		break;
 
 	case PPPOL2TP_SO_REORDERTO:
 		session->reorder_timeout = msecs_to_jiffies(val);
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: set reorder_timeout=%d\n",
 			  session->name, session->reorder_timeout);
 		break;
@@ -1427,7 +1476,7 @@
 	switch (optname) {
 	case PPPOL2TP_SO_DEBUG:
 		*val = tunnel->debug;
-		l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n",
+		l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
 			  tunnel->name, tunnel->debug);
 		break;
 
@@ -1450,31 +1499,31 @@
 	switch (optname) {
 	case PPPOL2TP_SO_RECVSEQ:
 		*val = session->recv_seq;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: get recv_seq=%d\n", session->name, *val);
 		break;
 
 	case PPPOL2TP_SO_SENDSEQ:
 		*val = session->send_seq;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: get send_seq=%d\n", session->name, *val);
 		break;
 
 	case PPPOL2TP_SO_LNSMODE:
 		*val = session->lns_mode;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: get lns_mode=%d\n", session->name, *val);
 		break;
 
 	case PPPOL2TP_SO_DEBUG:
 		*val = session->debug;
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n",
+		l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
 			  session->name, *val);
 		break;
 
 	case PPPOL2TP_SO_REORDERTO:
 		*val = (int) jiffies_to_msecs(session->reorder_timeout);
-		l2tp_info(session, PPPOL2TP_MSG_CONTROL,
+		l2tp_info(session, L2TP_MSG_CONTROL,
 			  "%s: get reorder_timeout=%d\n", session->name, *val);
 		break;
 
@@ -1653,8 +1702,9 @@
 {
 	struct l2tp_session *session = v;
 	struct l2tp_tunnel *tunnel = session->tunnel;
-	struct pppol2tp_session *ps = l2tp_session_priv(session);
-	struct pppox_sock *po = pppox_sk(ps->sock);
+	unsigned char state;
+	char user_data_ok;
+	struct sock *sk;
 	u32 ip = 0;
 	u16 port = 0;
 
@@ -1664,6 +1714,15 @@
 		port = ntohs(inet->inet_sport);
 	}
 
+	sk = pppol2tp_session_get_sock(session);
+	if (sk) {
+		state = sk->sk_state;
+		user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N';
+	} else {
+		state = 0;
+		user_data_ok = 'N';
+	}
+
 	seq_printf(m, "  SESSION '%s' %08X/%d %04X/%04X -> "
 		   "%04X/%04X %d %c\n",
 		   session->name, ip, port,
@@ -1671,9 +1730,7 @@
 		   session->session_id,
 		   tunnel->peer_tunnel_id,
 		   session->peer_session_id,
-		   ps->sock->sk_state,
-		   (session == ps->sock->sk_user_data) ?
-		   'Y' : 'N');
+		   state, user_data_ok);
 	seq_printf(m, "   %d/%d/%c/%c/%s %08x %u\n",
 		   session->mtu, session->mru,
 		   session->recv_seq ? 'R' : '-',
@@ -1690,8 +1747,12 @@
 		   atomic_long_read(&session->stats.rx_bytes),
 		   atomic_long_read(&session->stats.rx_errors));
 
-	if (po)
+	if (sk) {
+		struct pppox_sock *po = pppox_sk(sk);
+
 		seq_printf(m, "   interface %s\n", ppp_dev_name(&po->chan));
+		sock_put(sk);
+	}
 }
 
 static int pppol2tp_seq_show(struct seq_file *m, void *v)
@@ -1878,3 +1939,4 @@
 MODULE_LICENSE("GPL");
 MODULE_VERSION(PPPOL2TP_DRV_VERSION);
 MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP));
+MODULE_ALIAS_L2TP_PWTYPE(7);