Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from David Miller:

 1) Support 6Ghz band in ath11k driver, from Rajkumar Manoharan.

 2) Support UDP segmentation in code TSO code, from Eric Dumazet.

 3) Allow flashing different flash images in cxgb4 driver, from Vishal
    Kulkarni.

 4) Add drop frames counter and flow status to tc flower offloading,
    from Po Liu.

 5) Support n-tuple filters in cxgb4, from Vishal Kulkarni.

 6) Various new indirect call avoidance, from Eric Dumazet and Brian
    Vazquez.

 7) Fix BPF verifier failures on 32-bit pointer arithmetic, from
    Yonghong Song.

 8) Support querying and setting hardware address of a port function via
    devlink, use this in mlx5, from Parav Pandit.

 9) Support hw ipsec offload on bonding slaves, from Jarod Wilson.

10) Switch qca8k driver over to phylink, from Jonathan McDowell.

11) In bpftool, show list of processes holding BPF FD references to
    maps, programs, links, and btf objects. From Andrii Nakryiko.

12) Several conversions over to generic power management, from Vaibhav
    Gupta.

13) Add support for SO_KEEPALIVE et al. to bpf_setsockopt(), from Dmitry
    Yakunin.

14) Various https url conversions, from Alexander A. Klimov.

15) Timestamping and PHC support for mscc PHY driver, from Antoine
    Tenart.

16) Support bpf iterating over tcp and udp sockets, from Yonghong Song.

17) Support 5GBASE-T i40e NICs, from Aleksandr Loktionov.

18) Add kTLS RX HW offload support to mlx5e, from Tariq Toukan.

19) Fix the ->ndo_start_xmit() return type to be netdev_tx_t in several
    drivers. From Luc Van Oostenryck.

20) XDP support for xen-netfront, from Denis Kirjanov.

21) Support receive buffer autotuning in MPTCP, from Florian Westphal.

22) Support EF100 chip in sfc driver, from Edward Cree.

23) Add XDP support to mvpp2 driver, from Matteo Croce.

24) Support MPTCP in sock_diag, from Paolo Abeni.

25) Commonize UDP tunnel offloading code by creating udp_tunnel_nic
    infrastructure, from Jakub Kicinski.

26) Several pci_ --> dma_ API conversions, from Christophe JAILLET.

27) Add FLOW_ACTION_POLICE support to mlxsw, from Ido Schimmel.

28) Add SK_LOOKUP bpf program type, from Jakub Sitnicki.

29) Refactor a lot of networking socket option handling code in order to
    avoid set_fs() calls, from Christoph Hellwig.

30) Add rfc4884 support to icmp code, from Willem de Bruijn.

31) Support TBF offload in dpaa2-eth driver, from Ioana Ciornei.

32) Support XDP_REDIRECT in qede driver, from Alexander Lobakin.

33) Support PCI relaxed ordering in mlx5 driver, from Aya Levin.

34) Support TCP syncookies in MPTCP, from Flowian Westphal.

35) Fix several tricky cases of PMTU handling wrt. briding, from Stefano
    Brivio.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2056 commits)
  net: thunderx: initialize VF's mailbox mutex before first usage
  usb: hso: remove bogus check for EINPROGRESS
  usb: hso: no complaint about kmalloc failure
  hso: fix bailout in error case of probe
  ip_tunnel_core: Fix build for archs without _HAVE_ARCH_IPV6_CSUM
  selftests/net: relax cpu affinity requirement in msg_zerocopy test
  mptcp: be careful on subflow creation
  selftests: rtnetlink: make kci_test_encap() return sub-test result
  selftests: rtnetlink: correct the final return value for the test
  net: dsa: sja1105: use detected device id instead of DT one on mismatch
  tipc: set ub->ifindex for local ipv6 address
  ipv6: add ipv6_dev_find()
  net: openvswitch: silence suspicious RCU usage warning
  Revert "vxlan: fix tos value before xmit"
  ptp: only allow phase values lower than 1 period
  farsync: switch from 'pci_' to 'dma_' API
  wan: wanxl: switch from 'pci_' to 'dma_' API
  hv_netvsc: do not use VF device if link is down
  dpaa2-eth: Fix passing zero to 'PTR_ERR' warning
  net: macb: Properly handle phylink on at91sam9x
  ...

1 files changed, 129 insertions, 118 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 6434d17e6e8e..701fc72ad9f4 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
-/*
- * L2TP core.
+/* L2TP core.
  *
  * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
  *
@@ -94,7 +93,7 @@ struct l2tp_skb_cb {
 	unsigned long		expires;
 };
 
-#define L2TP_SKB_CB(skb)	((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)])
+#define L2TP_SKB_CB(skb)	((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)])
 
 static struct workqueue_struct *l2tp_wq;
 
@@ -102,8 +101,10 @@ static struct workqueue_struct *l2tp_wq;
 static unsigned int l2tp_net_id;
 struct l2tp_net {
 	struct list_head l2tp_tunnel_list;
+	/* Lock for write access to l2tp_tunnel_list */
 	spinlock_t l2tp_tunnel_list_lock;
 	struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2];
+	/* Lock for write access to l2tp_session_hlist */
 	spinlock_t l2tp_session_hlist_lock;
 };
 
@@ -134,7 +135,6 @@ static inline struct hlist_head *
 l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id)
 {
 	return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)];
-
 }
 
 /* Session hash list.
@@ -149,12 +149,51 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id)
 	return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)];
 }
 
-void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
+static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
 {
 	sock_put(tunnel->sock);
 	/* the tunnel is freed in the socket destructor */
 }
-EXPORT_SYMBOL(l2tp_tunnel_free);
+
+static void l2tp_session_free(struct l2tp_session *session)
+{
+	struct l2tp_tunnel *tunnel = session->tunnel;
+
+	if (tunnel) {
+		if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC))
+			goto out;
+		l2tp_tunnel_dec_refcount(tunnel);
+	}
+
+out:
+	kfree(session);
+}
+
+void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
+{
+	refcount_inc(&tunnel->ref_count);
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount);
+
+void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
+{
+	if (refcount_dec_and_test(&tunnel->ref_count))
+		l2tp_tunnel_free(tunnel);
+}
+EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount);
+
+void l2tp_session_inc_refcount(struct l2tp_session *session)
+{
+	refcount_inc(&session->ref_count);
+}
+EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount);
+
+void l2tp_session_dec_refcount(struct l2tp_session *session)
+{
+	if (refcount_dec_and_test(&session->ref_count))
+		l2tp_session_free(session);
+}
+EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount);
 
 /* 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)
@@ -412,7 +451,7 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
 	}
 
 	/* call private receive handler */
-	if (session->recv_skb != NULL)
+	if (session->recv_skb)
 		(*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length);
 	else
 		kfree_skb(skb);
@@ -621,8 +660,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		      int length)
 {
 	struct l2tp_tunnel *tunnel = session->tunnel;
+	u32 ns = 0, nr = 0;
 	int offset;
-	u32 ns, nr;
 
 	/* Parse and check optional cookie */
 	if (session->peer_cookie_len > 0) {
@@ -644,13 +683,12 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 	 * the control of the LNS.  If no sequence numbers present but
 	 * we were expecting them, discard frame.
 	 */
-	ns = nr = 0;
 	L2TP_SKB_CB(skb)->has_seq = 0;
 	if (tunnel->version == L2TP_HDR_VER_2) {
 		if (hdrflags & L2TP_HDRFLAG_S) {
-			ns = ntohs(*(__be16 *) ptr);
+			ns = ntohs(*(__be16 *)ptr);
 			ptr += 2;
-			nr = ntohs(*(__be16 *) ptr);
+			nr = ntohs(*(__be16 *)ptr);
 			ptr += 2;
 
 			/* Store L2TP info in the skb */
@@ -662,7 +700,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 				 session->name, ns, nr, session->nr);
 		}
 	} else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) {
-		u32 l2h = ntohl(*(__be32 *) ptr);
+		u32 l2h = ntohl(*(__be32 *)ptr);
 
 		if (l2h & 0x40000000) {
 			ns = l2h & 0x00ffffff;
@@ -679,11 +717,11 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 	}
 
 	if (L2TP_SKB_CB(skb)->has_seq) {
-		/* Received a packet with sequence numbers. If we're the LNS,
+		/* Received a packet with sequence numbers. If we're the LAC,
 		 * check if we sre sending sequence numbers and if not,
 		 * configure it so.
 		 */
-		if ((!session->lns_mode) && (!session->send_seq)) {
+		if (!session->lns_mode && !session->send_seq) {
 			l2tp_info(session, L2TP_MSG_SEQ,
 				  "%s: requested to enable seq numbers by LNS\n",
 				  session->name);
@@ -707,7 +745,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		 * If we're the LNS and we're sending sequence numbers, the
 		 * LAC is broken. Discard the frame.
 		 */
-		if ((!session->lns_mode) && (session->send_seq)) {
+		if (!session->lns_mode && session->send_seq) {
 			l2tp_info(session, L2TP_MSG_SEQ,
 				  "%s: requested to disable seq numbers by LNS\n",
 				  session->name);
@@ -770,20 +808,21 @@ discard:
 	atomic_long_inc(&session->stats.rx_errors);
 	kfree_skb(skb);
 }
-EXPORT_SYMBOL(l2tp_recv_common);
+EXPORT_SYMBOL_GPL(l2tp_recv_common);
 
 /* Drop skbs from the session's reorder_q
  */
-static int l2tp_session_queue_purge(struct l2tp_session *session)
+static void l2tp_session_queue_purge(struct l2tp_session *session)
 {
 	struct sk_buff *skb = NULL;
-	BUG_ON(!session);
-	BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+
+	if (WARN_ON(session->magic != L2TP_SESSION_MAGIC))
+		return;
+
 	while ((skb = skb_dequeue(&session->reorder_q))) {
 		atomic_long_inc(&session->stats.rx_errors);
 		kfree_skb(skb);
 	}
-	return 0;
 }
 
 /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame
@@ -825,10 +864,11 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb)
 	}
 
 	/* Point to L2TP header */
-	optr = ptr = skb->data;
+	optr = skb->data;
+	ptr = skb->data;
 
 	/* Get L2TP header flags */
-	hdrflags = ntohs(*(__be16 *) ptr);
+	hdrflags = ntohs(*(__be16 *)ptr);
 
 	/* Check protocol version */
 	version = hdrflags & L2TP_HDR_VER_MASK;
@@ -859,14 +899,14 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb)
 			ptr += 2;
 
 		/* Extract tunnel and session ID */
-		tunnel_id = ntohs(*(__be16 *) ptr);
+		tunnel_id = ntohs(*(__be16 *)ptr);
 		ptr += 2;
-		session_id = ntohs(*(__be16 *) ptr);
+		session_id = ntohs(*(__be16 *)ptr);
 		ptr += 2;
 	} else {
 		ptr += 2;	/* skip reserved bits */
 		tunnel_id = tunnel->tunnel_id;
-		session_id = ntohl(*(__be32 *) ptr);
+		session_id = ntohl(*(__be32 *)ptr);
 		ptr += 4;
 	}
 
@@ -910,7 +950,7 @@ int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	struct l2tp_tunnel *tunnel;
 
 	tunnel = rcu_dereference_sk_user_data(sk);
-	if (tunnel == NULL)
+	if (!tunnel)
 		goto pass_up;
 
 	l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n",
@@ -971,13 +1011,13 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf)
 	 */
 	if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
 		u16 flags = L2TP_HDR_VER_3;
-		*((__be16 *) bufp) = htons(flags);
+		*((__be16 *)bufp) = htons(flags);
 		bufp += 2;
-		*((__be16 *) bufp) = 0;
+		*((__be16 *)bufp) = 0;
 		bufp += 2;
 	}
 
-	*((__be32 *) bufp) = htonl(session->peer_session_id);
+	*((__be32 *)bufp) = htonl(session->peer_session_id);
 	bufp += 4;
 	if (session->cookie_len) {
 		memcpy(bufp, &session->cookie[0], session->cookie_len);
@@ -1076,7 +1116,10 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 	}
 
 	/* Setup L2TP header */
-	session->build_header(session, __skb_push(skb, hdr_len));
+	if (tunnel->version == L2TP_HDR_VER_2)
+		l2tp_build_l2tpv2_header(session, __skb_push(skb, hdr_len));
+	else
+		l2tp_build_l2tpv3_header(session, __skb_push(skb, hdr_len));
 
 	/* Reset skb netfilter state */
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
@@ -1121,8 +1164,8 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 				      &sk->sk_v6_daddr, udp_len);
 		else
 #endif
-		udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr,
-			     inet->inet_daddr, udp_len);
+			udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr,
+				     inet->inet_daddr, udp_len);
 		break;
 
 	case L2TP_ENCAPTYPE_IP:
@@ -1149,7 +1192,7 @@ static void l2tp_tunnel_destruct(struct sock *sk)
 {
 	struct l2tp_tunnel *tunnel = l2tp_tunnel(sk);
 
-	if (tunnel == NULL)
+	if (!tunnel)
 		goto end;
 
 	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name);
@@ -1179,6 +1222,30 @@ end:
 	return;
 }
 
+/* Remove an l2tp session from l2tp_core's hash lists. */
+static void l2tp_session_unhash(struct l2tp_session *session)
+{
+	struct l2tp_tunnel *tunnel = session->tunnel;
+
+	/* Remove the session from core hashes */
+	if (tunnel) {
+		/* Remove from the per-tunnel hash */
+		write_lock_bh(&tunnel->hlist_lock);
+		hlist_del_init(&session->hlist);
+		write_unlock_bh(&tunnel->hlist_lock);
+
+		/* For L2TPv3 we have a per-net hash: remove from there, too */
+		if (tunnel->version != L2TP_HDR_VER_2) {
+			struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
+
+			spin_lock_bh(&pn->l2tp_session_hlist_lock);
+			hlist_del_init_rcu(&session->global_hlist);
+			spin_unlock_bh(&pn->l2tp_session_hlist_lock);
+			synchronize_rcu();
+		}
+	}
+}
+
 /* When the tunnel is closed, all the attached sessions need to go too.
  */
 static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
@@ -1188,8 +1255,6 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 	struct hlist_node *tmp;
 	struct l2tp_session *session;
 
-	BUG_ON(tunnel == NULL);
-
 	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n",
 		  tunnel->name);
 
@@ -1210,10 +1275,10 @@ again:
 
 			write_unlock_bh(&tunnel->hlist_lock);
 
-			__l2tp_session_unhash(session);
+			l2tp_session_unhash(session);
 			l2tp_session_queue_purge(session);
 
-			if (session->session_close != NULL)
+			if (session->session_close)
 				(*session->session_close)(session);
 
 			l2tp_session_dec_refcount(session);
@@ -1284,10 +1349,10 @@ static void l2tp_tunnel_del_work(struct work_struct *work)
  * exit hook.
  */
 static int l2tp_tunnel_sock_create(struct net *net,
-				u32 tunnel_id,
-				u32 peer_tunnel_id,
-				struct l2tp_tunnel_cfg *cfg,
-				struct socket **sockp)
+				   u32 tunnel_id,
+				   u32 peer_tunnel_id,
+				   struct l2tp_tunnel_cfg *cfg,
+				   struct socket **sockp)
 {
 	int err = -EINVAL;
 	struct socket *sock = NULL;
@@ -1305,9 +1370,9 @@ static int l2tp_tunnel_sock_create(struct net *net,
 			memcpy(&udp_conf.peer_ip6, cfg->peer_ip6,
 			       sizeof(udp_conf.peer_ip6));
 			udp_conf.use_udp6_tx_checksums =
-			  ! cfg->udp6_zero_tx_checksums;
+			  !cfg->udp6_zero_tx_checksums;
 			udp_conf.use_udp6_rx_checksums =
-			  ! cfg->udp6_zero_rx_checksums;
+			  !cfg->udp6_zero_rx_checksums;
 		} else
 #endif
 		{
@@ -1332,7 +1397,7 @@ static int l2tp_tunnel_sock_create(struct net *net,
 			struct sockaddr_l2tpip6 ip6_addr = {0};
 
 			err = sock_create_kern(net, AF_INET6, SOCK_DGRAM,
-					  IPPROTO_L2TP, &sock);
+					       IPPROTO_L2TP, &sock);
 			if (err < 0)
 				goto out;
 
@@ -1340,7 +1405,7 @@ static int l2tp_tunnel_sock_create(struct net *net,
 			memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6,
 			       sizeof(ip6_addr.l2tp_addr));
 			ip6_addr.l2tp_conn_id = tunnel_id;
-			err = kernel_bind(sock, (struct sockaddr *) &ip6_addr,
+			err = kernel_bind(sock, (struct sockaddr *)&ip6_addr,
 					  sizeof(ip6_addr));
 			if (err < 0)
 				goto out;
@@ -1350,7 +1415,7 @@ static int l2tp_tunnel_sock_create(struct net *net,
 			       sizeof(ip6_addr.l2tp_addr));
 			ip6_addr.l2tp_conn_id = peer_tunnel_id;
 			err = kernel_connect(sock,
-					     (struct sockaddr *) &ip6_addr,
+					     (struct sockaddr *)&ip6_addr,
 					     sizeof(ip6_addr), 0);
 			if (err < 0)
 				goto out;
@@ -1360,14 +1425,14 @@ static int l2tp_tunnel_sock_create(struct net *net,
 			struct sockaddr_l2tpip ip_addr = {0};
 
 			err = sock_create_kern(net, AF_INET, SOCK_DGRAM,
-					  IPPROTO_L2TP, &sock);
+					       IPPROTO_L2TP, &sock);
 			if (err < 0)
 				goto out;
 
 			ip_addr.l2tp_family = AF_INET;
 			ip_addr.l2tp_addr = cfg->local_ip;
 			ip_addr.l2tp_conn_id = tunnel_id;
-			err = kernel_bind(sock, (struct sockaddr *) &ip_addr,
+			err = kernel_bind(sock, (struct sockaddr *)&ip_addr,
 					  sizeof(ip_addr));
 			if (err < 0)
 				goto out;
@@ -1375,7 +1440,7 @@ static int l2tp_tunnel_sock_create(struct net *net,
 			ip_addr.l2tp_family = AF_INET;
 			ip_addr.l2tp_addr = cfg->peer_ip;
 			ip_addr.l2tp_conn_id = peer_tunnel_id;
-			err = kernel_connect(sock, (struct sockaddr *) &ip_addr,
+			err = kernel_connect(sock, (struct sockaddr *)&ip_addr,
 					     sizeof(ip_addr), 0);
 			if (err < 0)
 				goto out;
@@ -1388,7 +1453,7 @@ static int l2tp_tunnel_sock_create(struct net *net,
 
 out:
 	*sockp = sock;
-	if ((err < 0) && sock) {
+	if (err < 0 && sock) {
 		kernel_sock_shutdown(sock, SHUT_RDWR);
 		sock_release(sock);
 		*sockp = NULL;
@@ -1399,17 +1464,18 @@ out:
 
 static struct lock_class_key l2tp_socket_class;
 
-int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp)
+int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id,
+		       struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp)
 {
 	struct l2tp_tunnel *tunnel = NULL;
 	int err;
 	enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP;
 
-	if (cfg != NULL)
+	if (cfg)
 		encap = cfg->encap;
 
-	tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL);
-	if (tunnel == NULL) {
+	tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
+	if (!tunnel) {
 		err = -ENOMEM;
 		goto err;
 	}
@@ -1424,7 +1490,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	rwlock_init(&tunnel->hlist_lock);
 	tunnel->acpt_newsess = true;
 
-	if (cfg != NULL)
+	if (cfg)
 		tunnel->debug = cfg->debug;
 
 	tunnel->encap = encap;
@@ -1557,67 +1623,17 @@ void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);
 
-/* Really kill the session.
- */
-void l2tp_session_free(struct l2tp_session *session)
-{
-	struct l2tp_tunnel *tunnel = session->tunnel;
-
-	BUG_ON(refcount_read(&session->ref_count) != 0);
-
-	if (tunnel) {
-		BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
-		l2tp_tunnel_dec_refcount(tunnel);
-	}
-
-	kfree(session);
-}
-EXPORT_SYMBOL_GPL(l2tp_session_free);
-
-/* Remove an l2tp session from l2tp_core's hash lists.
- * Provides a tidyup interface for pseudowire code which can't just route all
- * shutdown via. l2tp_session_delete and a pseudowire-specific session_close
- * callback.
- */
-void __l2tp_session_unhash(struct l2tp_session *session)
-{
-	struct l2tp_tunnel *tunnel = session->tunnel;
-
-	/* Remove the session from core hashes */
-	if (tunnel) {
-		/* Remove from the per-tunnel hash */
-		write_lock_bh(&tunnel->hlist_lock);
-		hlist_del_init(&session->hlist);
-		write_unlock_bh(&tunnel->hlist_lock);
-
-		/* For L2TPv3 we have a per-net hash: remove from there, too */
-		if (tunnel->version != L2TP_HDR_VER_2) {
-			struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
-			spin_lock_bh(&pn->l2tp_session_hlist_lock);
-			hlist_del_init_rcu(&session->global_hlist);
-			spin_unlock_bh(&pn->l2tp_session_hlist_lock);
-			synchronize_rcu();
-		}
-	}
-}
-EXPORT_SYMBOL_GPL(__l2tp_session_unhash);
-
-/* This function is used by the netlink SESSION_DELETE command and by
-   pseudowire modules.
- */
-int l2tp_session_delete(struct l2tp_session *session)
+void l2tp_session_delete(struct l2tp_session *session)
 {
 	if (test_and_set_bit(0, &session->dead))
-		return 0;
+		return;
 
-	__l2tp_session_unhash(session);
+	l2tp_session_unhash(session);
 	l2tp_session_queue_purge(session);
-	if (session->session_close != NULL)
+	if (session->session_close)
 		(*session->session_close)(session);
 
 	l2tp_session_dec_refcount(session);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(l2tp_session_delete);
 
@@ -1636,16 +1652,16 @@ void l2tp_session_set_header_len(struct l2tp_session *session, int version)
 		if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP)
 			session->hdr_len += 4;
 	}
-
 }
 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 *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;
 
-	session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL);
-	if (session != NULL) {
+	session = kzalloc(sizeof(*session) + priv_size, GFP_KERNEL);
+	if (session) {
 		session->magic = L2TP_SESSION_MAGIC;
 		session->tunnel = tunnel;
 
@@ -1687,11 +1703,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn
 			memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len);
 		}
 
-		if (tunnel->version == L2TP_HDR_VER_2)
-			session->build_header = l2tp_build_l2tpv2_header;
-		else
-			session->build_header = l2tp_build_l2tpv3_header;
-
 		l2tp_session_set_header_len(session, tunnel->version);
 
 		refcount_set(&session->ref_count, 1);