1 files changed, 121 insertions, 208 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 701fc72ad9f4..7be5103ff2a8 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -61,6 +61,10 @@
 #include <linux/atomic.h>
 
 #include "l2tp_core.h"
+#include "trace.h"
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
 
 #define L2TP_DRV_VERSION	"V2.0"
 
@@ -116,11 +120,6 @@ static bool l2tp_sk_is_v6(struct sock *sk)
 }
 #endif
 
-static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk)
-{
-	return sk->sk_user_data;
-}
-
 static inline struct l2tp_net *l2tp_pernet(const struct net *net)
 {
 	return net_generic(net, l2tp_net_id);
@@ -151,23 +150,30 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id)
 
 static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
 {
+	trace_free_tunnel(tunnel);
 	sock_put(tunnel->sock);
 	/* the tunnel is freed in the socket destructor */
 }
 
 static void l2tp_session_free(struct l2tp_session *session)
 {
-	struct l2tp_tunnel *tunnel = session->tunnel;
+	trace_free_session(session);
+	if (session->tunnel)
+		l2tp_tunnel_dec_refcount(session->tunnel);
+	kfree(session);
+}
 
-	if (tunnel) {
+struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk)
+{
+	struct l2tp_tunnel *tunnel = sk->sk_user_data;
+
+	if (tunnel)
 		if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC))
-			goto out;
-		l2tp_tunnel_dec_refcount(tunnel);
-	}
+			return NULL;
 
-out:
-	kfree(session);
+	return tunnel;
 }
+EXPORT_SYMBOL_GPL(l2tp_sk_to_tunnel);
 
 void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel)
 {
@@ -381,6 +387,8 @@ int l2tp_session_register(struct l2tp_session *session,
 	hlist_add_head(&session->hlist, head);
 	write_unlock_bh(&tunnel->hlist_lock);
 
+	trace_register_session(session);
+
 	return 0;
 
 err_tlock_pnlock:
@@ -409,10 +417,6 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk
 	skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
 		if (L2TP_SKB_CB(skbp)->ns > ns) {
 			__skb_queue_before(&session->reorder_q, skbp, skb);
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
-				 session->name, ns, L2TP_SKB_CB(skbp)->ns,
-				 skb_queue_len(&session->reorder_q));
 			atomic_long_inc(&session->stats.rx_oos_packets);
 			goto out;
 		}
@@ -445,9 +449,7 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
 		/* Bump our Nr */
 		session->nr++;
 		session->nr &= session->nr_max;
-
-		l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n",
-			 session->name, session->nr);
+		trace_session_seqnum_update(session);
 	}
 
 	/* call private receive handler */
@@ -472,37 +474,27 @@ static void l2tp_recv_dequeue(struct l2tp_session *session)
 start:
 	spin_lock_bh(&session->reorder_q.lock);
 	skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
-		if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) {
+		struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb);
+
+		/* If the packet has been pending on the queue for too long, discard it */
+		if (time_after(jiffies, cb->expires)) {
 			atomic_long_inc(&session->stats.rx_seq_discards);
 			atomic_long_inc(&session->stats.rx_errors);
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n",
-				 session->name, L2TP_SKB_CB(skb)->ns,
-				 L2TP_SKB_CB(skb)->length, session->nr,
-				 skb_queue_len(&session->reorder_q));
+			trace_session_pkt_expired(session, cb->ns);
 			session->reorder_skip = 1;
 			__skb_unlink(skb, &session->reorder_q);
 			kfree_skb(skb);
 			continue;
 		}
 
-		if (L2TP_SKB_CB(skb)->has_seq) {
+		if (cb->has_seq) {
 			if (session->reorder_skip) {
-				l2tp_dbg(session, L2TP_MSG_SEQ,
-					 "%s: advancing nr to next pkt: %u -> %u",
-					 session->name, session->nr,
-					 L2TP_SKB_CB(skb)->ns);
 				session->reorder_skip = 0;
-				session->nr = L2TP_SKB_CB(skb)->ns;
+				session->nr = cb->ns;
+				trace_session_seqnum_reset(session);
 			}
-			if (L2TP_SKB_CB(skb)->ns != session->nr) {
-				l2tp_dbg(session, L2TP_MSG_SEQ,
-					 "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n",
-					 session->name, L2TP_SKB_CB(skb)->ns,
-					 L2TP_SKB_CB(skb)->length, session->nr,
-					 skb_queue_len(&session->reorder_q));
+			if (cb->ns != session->nr)
 				goto out;
-			}
 		}
 		__skb_unlink(skb, &session->reorder_q);
 
@@ -535,14 +527,13 @@ static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr)
  */
 static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb)
 {
-	if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) {
+	struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb);
+
+	if (!l2tp_seq_check_rx_window(session, cb->ns)) {
 		/* Packet sequence number is outside allowed window.
 		 * Discard it.
 		 */
-		l2tp_dbg(session, L2TP_MSG_SEQ,
-			 "%s: pkt %u len %d discarded, outside window, nr=%u\n",
-			 session->name, L2TP_SKB_CB(skb)->ns,
-			 L2TP_SKB_CB(skb)->length, session->nr);
+		trace_session_pkt_outside_rx_window(session, cb->ns);
 		goto discard;
 	}
 
@@ -559,10 +550,10 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb)
 	 * is seen. After nr_oos_count_max in-sequence packets, reset the
 	 * sequence number to re-enable packet reception.
 	 */
-	if (L2TP_SKB_CB(skb)->ns == session->nr) {
+	if (cb->ns == session->nr) {
 		skb_queue_tail(&session->reorder_q, skb);
 	} else {
-		u32 nr_oos = L2TP_SKB_CB(skb)->ns;
+		u32 nr_oos = cb->ns;
 		u32 nr_next = (session->nr_oos + 1) & session->nr_max;
 
 		if (nr_oos == nr_next)
@@ -573,17 +564,10 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb)
 		session->nr_oos = nr_oos;
 		if (session->nr_oos_count > session->nr_oos_count_max) {
 			session->reorder_skip = 1;
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: %d oos packets received. Resetting sequence numbers\n",
-				 session->name, session->nr_oos_count);
 		}
 		if (!session->reorder_skip) {
 			atomic_long_inc(&session->stats.rx_seq_discards);
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n",
-				 session->name, L2TP_SKB_CB(skb)->ns,
-				 L2TP_SKB_CB(skb)->length, session->nr,
-				 skb_queue_len(&session->reorder_q));
+			trace_session_pkt_oos(session, cb->ns);
 			goto discard;
 		}
 		skb_queue_tail(&session->reorder_q, skb);
@@ -660,16 +644,14 @@ 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;
 
 	/* Parse and check optional cookie */
 	if (session->peer_cookie_len > 0) {
 		if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) {
-			l2tp_info(tunnel, L2TP_MSG_DATA,
-				  "%s: cookie mismatch (%u/%u). Discarding.\n",
-				  tunnel->name, tunnel->tunnel_id,
-				  session->session_id);
+			pr_warn_ratelimited("%s: cookie mismatch (%u/%u). Discarding.\n",
+					    tunnel->name, tunnel->tunnel_id,
+					    session->session_id);
 			atomic_long_inc(&session->stats.rx_cookie_discards);
 			goto discard;
 		}
@@ -686,32 +668,21 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 	L2TP_SKB_CB(skb)->has_seq = 0;
 	if (tunnel->version == L2TP_HDR_VER_2) {
 		if (hdrflags & L2TP_HDRFLAG_S) {
-			ns = ntohs(*(__be16 *)ptr);
-			ptr += 2;
-			nr = ntohs(*(__be16 *)ptr);
-			ptr += 2;
-
 			/* Store L2TP info in the skb */
-			L2TP_SKB_CB(skb)->ns = ns;
+			L2TP_SKB_CB(skb)->ns = ntohs(*(__be16 *)ptr);
 			L2TP_SKB_CB(skb)->has_seq = 1;
+			ptr += 2;
+			/* Skip past nr in the header */
+			ptr += 2;
 
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: recv data ns=%u, nr=%u, session nr=%u\n",
-				 session->name, ns, nr, session->nr);
 		}
 	} else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) {
 		u32 l2h = ntohl(*(__be32 *)ptr);
 
 		if (l2h & 0x40000000) {
-			ns = l2h & 0x00ffffff;
-
 			/* Store L2TP info in the skb */
-			L2TP_SKB_CB(skb)->ns = ns;
+			L2TP_SKB_CB(skb)->ns = l2h & 0x00ffffff;
 			L2TP_SKB_CB(skb)->has_seq = 1;
-
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: recv data ns=%u, session nr=%u\n",
-				 session->name, ns, session->nr);
 		}
 		ptr += 4;
 	}
@@ -722,9 +693,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		 * configure it so.
 		 */
 		if (!session->lns_mode && !session->send_seq) {
-			l2tp_info(session, L2TP_MSG_SEQ,
-				  "%s: requested to enable seq numbers by LNS\n",
-				  session->name);
+			trace_session_seqnum_lns_enable(session);
 			session->send_seq = 1;
 			l2tp_session_set_header_len(session, tunnel->version);
 		}
@@ -733,9 +702,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		 * If user has configured mandatory sequence numbers, discard.
 		 */
 		if (session->recv_seq) {
-			l2tp_warn(session, L2TP_MSG_SEQ,
-				  "%s: recv data has no seq numbers when required. Discarding.\n",
-				  session->name);
+			pr_warn_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n",
+					    session->name);
 			atomic_long_inc(&session->stats.rx_seq_discards);
 			goto discard;
 		}
@@ -746,15 +714,12 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		 * LAC is broken. Discard the frame.
 		 */
 		if (!session->lns_mode && session->send_seq) {
-			l2tp_info(session, L2TP_MSG_SEQ,
-				  "%s: requested to disable seq numbers by LNS\n",
-				  session->name);
+			trace_session_seqnum_lns_disable(session);
 			session->send_seq = 0;
 			l2tp_session_set_header_len(session, tunnel->version);
 		} else if (session->send_seq) {
-			l2tp_warn(session, L2TP_MSG_SEQ,
-				  "%s: recv data has no seq numbers when required. Discarding.\n",
-				  session->name);
+			pr_warn_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n",
+					    session->name);
 			atomic_long_inc(&session->stats.rx_seq_discards);
 			goto discard;
 		}
@@ -816,9 +781,6 @@ static void l2tp_session_queue_purge(struct l2tp_session *session)
 {
 	struct sk_buff *skb = NULL;
 
-	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);
@@ -847,22 +809,11 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb)
 
 	/* Short packet? */
 	if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) {
-		l2tp_info(tunnel, L2TP_MSG_DATA,
-			  "%s: recv short packet (len=%d)\n",
-			  tunnel->name, skb->len);
+		pr_warn_ratelimited("%s: recv short packet (len=%d)\n",
+				    tunnel->name, skb->len);
 		goto error;
 	}
 
-	/* Trace packet contents, if enabled */
-	if (tunnel->debug & L2TP_MSG_DATA) {
-		length = min(32u, skb->len);
-		if (!pskb_may_pull(skb, length))
-			goto error;
-
-		pr_debug("%s: recv\n", tunnel->name);
-		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
-	}
-
 	/* Point to L2TP header */
 	optr = skb->data;
 	ptr = skb->data;
@@ -873,9 +824,8 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb)
 	/* Check protocol version */
 	version = hdrflags & L2TP_HDR_VER_MASK;
 	if (version != tunnel->version) {
-		l2tp_info(tunnel, L2TP_MSG_DATA,
-			  "%s: recv protocol version mismatch: got %d expected %d\n",
-			  tunnel->name, version, tunnel->version);
+		pr_warn_ratelimited("%s: recv protocol version mismatch: got %d expected %d\n",
+				    tunnel->name, version, tunnel->version);
 		goto error;
 	}
 
@@ -883,12 +833,8 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb)
 	length = skb->len;
 
 	/* If type is control packet, it is handled by userspace. */
-	if (hdrflags & L2TP_HDRFLAG_T) {
-		l2tp_dbg(tunnel, L2TP_MSG_DATA,
-			 "%s: recv control packet, len=%d\n",
-			 tunnel->name, length);
+	if (hdrflags & L2TP_HDRFLAG_T)
 		goto error;
-	}
 
 	/* Skip flags */
 	ptr += 2;
@@ -917,9 +863,8 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb)
 			l2tp_session_dec_refcount(session);
 
 		/* Not found? Pass to userspace to deal with */
-		l2tp_info(tunnel, L2TP_MSG_DATA,
-			  "%s: no session found (%u/%u). Passing up.\n",
-			  tunnel->name, tunnel_id, session_id);
+		pr_warn_ratelimited("%s: no session found (%u/%u). Passing up.\n",
+				    tunnel->name, tunnel_id, session_id);
 		goto error;
 	}
 
@@ -949,12 +894,17 @@ int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 {
 	struct l2tp_tunnel *tunnel;
 
+	/* Note that this is called from the encap_rcv hook inside an
+	 * RCU-protected region, but without the socket being locked.
+	 * Hence we use rcu_dereference_sk_user_data to access the
+	 * tunnel data structure rather the usual l2tp_sk_to_tunnel
+	 * accessor function.
+	 */
 	tunnel = rcu_dereference_sk_user_data(sk);
 	if (!tunnel)
 		goto pass_up;
-
-	l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n",
-		 tunnel->name, skb->len);
+	if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC))
+		goto pass_up;
 
 	if (l2tp_udp_recv_core(tunnel, skb))
 		goto pass_up;
@@ -993,8 +943,7 @@ static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf)
 		*bufp++ = 0;
 		session->ns++;
 		session->ns &= 0xffff;
-		l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n",
-			 session->name, session->ns);
+		trace_session_seqnum_update(session);
 	}
 
 	return bufp - optr;
@@ -1030,9 +979,7 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf)
 			l2h = 0x40000000 | session->ns;
 			session->ns++;
 			session->ns &= 0xffffff;
-			l2tp_dbg(session, L2TP_MSG_SEQ,
-				 "%s: updated ns to %u\n",
-				 session->name, session->ns);
+			trace_session_seqnum_update(session);
 		}
 
 		*((__be32 *)bufp) = htonl(l2h);
@@ -1042,74 +989,39 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf)
 	return bufp - optr;
 }
 
-static void l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
-			   struct flowi *fl, size_t data_len)
+/* Queue the packet to IP for output: tunnel socket lock must be held */
+static int l2tp_xmit_queue(struct l2tp_tunnel *tunnel, struct sk_buff *skb, struct flowi *fl)
 {
-	struct l2tp_tunnel *tunnel = session->tunnel;
-	unsigned int len = skb->len;
-	int error;
-
-	/* Debug */
-	if (session->send_seq)
-		l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes, ns=%u\n",
-			 session->name, data_len, session->ns - 1);
-	else
-		l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes\n",
-			 session->name, data_len);
-
-	if (session->debug & L2TP_MSG_DATA) {
-		int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
-		unsigned char *datap = skb->data + uhlen;
-
-		pr_debug("%s: xmit\n", session->name);
-		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET,
-				     datap, min_t(size_t, 32, len - uhlen));
-	}
+	int err;
 
-	/* Queue the packet to IP for output */
 	skb->ignore_df = 1;
 	skb_dst_drop(skb);
 #if IS_ENABLED(CONFIG_IPV6)
 	if (l2tp_sk_is_v6(tunnel->sock))
-		error = inet6_csk_xmit(tunnel->sock, skb, NULL);
+		err = inet6_csk_xmit(tunnel->sock, skb, NULL);
 	else
 #endif
-		error = ip_queue_xmit(tunnel->sock, skb, fl);
+		err = ip_queue_xmit(tunnel->sock, skb, fl);
 
-	/* Update stats */
-	if (error >= 0) {
-		atomic_long_inc(&tunnel->stats.tx_packets);
-		atomic_long_add(len, &tunnel->stats.tx_bytes);
-		atomic_long_inc(&session->stats.tx_packets);
-		atomic_long_add(len, &session->stats.tx_bytes);
-	} else {
-		atomic_long_inc(&tunnel->stats.tx_errors);
-		atomic_long_inc(&session->stats.tx_errors);
-	}
+	return err >= 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
 }
 
-/* If caller requires the skb to have a ppp header, the header must be
- * inserted in the skb data before calling this function.
- */
-int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len)
+static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, unsigned int *len)
 {
-	int data_len = skb->len;
 	struct l2tp_tunnel *tunnel = session->tunnel;
+	unsigned int data_len = skb->len;
 	struct sock *sk = tunnel->sock;
-	struct flowi *fl;
-	struct udphdr *uh;
-	struct inet_sock *inet;
-	int headroom;
-	int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
-	int udp_len;
+	int headroom, uhlen, udp_len;
 	int ret = NET_XMIT_SUCCESS;
+	struct inet_sock *inet;
+	struct udphdr *uh;
 
 	/* Check that there's enough headroom in the skb to insert IP,
 	 * UDP and L2TP headers. If not enough, expand it to
 	 * make room. Adjust truesize.
 	 */
-	headroom = NET_SKB_PAD + sizeof(struct iphdr) +
-		uhlen + hdr_len;
+	uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(*uh) : 0;
+	headroom = NET_SKB_PAD + sizeof(struct iphdr) + uhlen + session->hdr_len;
 	if (skb_cow_head(skb, headroom)) {
 		kfree_skb(skb);
 		return NET_XMIT_DROP;
@@ -1117,14 +1029,13 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 
 	/* Setup L2TP header */
 	if (tunnel->version == L2TP_HDR_VER_2)
-		l2tp_build_l2tpv2_header(session, __skb_push(skb, hdr_len));
+		l2tp_build_l2tpv2_header(session, __skb_push(skb, session->hdr_len));
 	else
-		l2tp_build_l2tpv3_header(session, __skb_push(skb, hdr_len));
+		l2tp_build_l2tpv3_header(session, __skb_push(skb, session->hdr_len));
 
 	/* Reset skb netfilter state */
 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
-			      IPSKB_REROUTED);
+	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED);
 	nf_reset_ct(skb);
 
 	bh_lock_sock(sk);
@@ -1143,8 +1054,12 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 		goto out_unlock;
 	}
 
+	/* Report transmitted length before we add encap header, which keeps
+	 * statistics consistent for both UDP and IP encap tx/rx paths.
+	 */
+	*len = skb->len;
+
 	inet = inet_sk(sk);
-	fl = &inet->cork.fl;
 	switch (tunnel->encap) {
 	case L2TP_ENCAPTYPE_UDP:
 		/* Setup UDP header */
@@ -1153,7 +1068,7 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 		uh = udp_hdr(skb);
 		uh->source = inet->inet_sport;
 		uh->dest = inet->inet_dport;
-		udp_len = uhlen + hdr_len + data_len;
+		udp_len = uhlen + session->hdr_len + data_len;
 		uh->len = htons(udp_len);
 
 		/* Calculate UDP checksum if configured to do so */
@@ -1172,12 +1087,34 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 		break;
 	}
 
-	l2tp_xmit_core(session, skb, fl, data_len);
+	ret = l2tp_xmit_queue(tunnel, skb, &inet->cork.fl);
+
 out_unlock:
 	bh_unlock_sock(sk);
 
 	return ret;
 }
+
+/* If caller requires the skb to have a ppp header, the header must be
+ * inserted in the skb data before calling this function.
+ */
+int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb)
+{
+	unsigned int len = 0;
+	int ret;
+
+	ret = l2tp_xmit_core(session, skb, &len);
+	if (ret == NET_XMIT_SUCCESS) {
+		atomic_long_inc(&session->tunnel->stats.tx_packets);
+		atomic_long_add(len, &session->tunnel->stats.tx_bytes);
+		atomic_long_inc(&session->stats.tx_packets);
+		atomic_long_add(len, &session->stats.tx_bytes);
+	} else {
+		atomic_long_inc(&session->tunnel->stats.tx_errors);
+		atomic_long_inc(&session->stats.tx_errors);
+	}
+	return ret;
+}
 EXPORT_SYMBOL_GPL(l2tp_xmit_skb);
 
 /*****************************************************************************
@@ -1190,13 +1127,11 @@ EXPORT_SYMBOL_GPL(l2tp_xmit_skb);
  */
 static void l2tp_tunnel_destruct(struct sock *sk)
 {
-	struct l2tp_tunnel *tunnel = l2tp_tunnel(sk);
+	struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk);
 
 	if (!tunnel)
 		goto end;
 
-	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name);
-
 	/* Disable udp encapsulation */
 	switch (tunnel->encap) {
 	case L2TP_ENCAPTYPE_UDP:
@@ -1255,34 +1190,16 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 	struct hlist_node *tmp;
 	struct l2tp_session *session;
 
-	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n",
-		  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]) {
 			session = hlist_entry(walk, struct l2tp_session, hlist);
-
-			l2tp_info(session, L2TP_MSG_CONTROL,
-				  "%s: closing session\n", session->name);
-
 			hlist_del_init(&session->hlist);
 
-			if (test_and_set_bit(0, &session->dead))
-				goto again;
-
 			write_unlock_bh(&tunnel->hlist_lock);
-
-			l2tp_session_unhash(session);
-			l2tp_session_queue_purge(session);
-
-			if (session->session_close)
-				(*session->session_close)(session);
-
-			l2tp_session_dec_refcount(session);
-
+			l2tp_session_delete(session);
 			write_lock_bh(&tunnel->hlist_lock);
 
 			/* Now restart from the beginning of this hash
@@ -1299,7 +1216,7 @@ again:
 /* Tunnel socket destroy hook for UDP encapsulation */
 static void l2tp_udp_encap_destroy(struct sock *sk)
 {
-	struct l2tp_tunnel *tunnel = l2tp_tunnel(sk);
+	struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk);
 
 	if (tunnel)
 		l2tp_tunnel_delete(tunnel);
@@ -1464,7 +1381,7 @@ 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,
+int l2tp_tunnel_create(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;
@@ -1483,16 +1400,12 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	tunnel->version = version;
 	tunnel->tunnel_id = tunnel_id;
 	tunnel->peer_tunnel_id = peer_tunnel_id;
-	tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS;
 
 	tunnel->magic = L2TP_TUNNEL_MAGIC;
 	sprintf(&tunnel->name[0], "tunl %u", tunnel_id);
 	rwlock_init(&tunnel->hlist_lock);
 	tunnel->acpt_newsess = true;
 
-	if (cfg)
-		tunnel->debug = cfg->debug;
-
 	tunnel->encap = encap;
 
 	refcount_set(&tunnel->ref_count, 1);
@@ -1597,6 +1510,8 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
 				   "l2tp_sock");
 	sk->sk_allocation = GFP_ATOMIC;
 
+	trace_register_tunnel(tunnel);
+
 	if (tunnel->fd >= 0)
 		sockfd_put(sock);
 
@@ -1617,6 +1532,7 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_register);
 void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 {
 	if (!test_and_set_bit(0, &tunnel->dead)) {
+		trace_delete_tunnel(tunnel);
 		l2tp_tunnel_inc_refcount(tunnel);
 		queue_work(l2tp_wq, &tunnel->del_work);
 	}
@@ -1628,6 +1544,7 @@ void l2tp_session_delete(struct l2tp_session *session)
 	if (test_and_set_bit(0, &session->dead))
 		return;
 
+	trace_delete_session(session);
 	l2tp_session_unhash(session);
 	l2tp_session_queue_purge(session);
 	if (session->session_close)
@@ -1686,12 +1603,8 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn
 		INIT_HLIST_NODE(&session->hlist);
 		INIT_HLIST_NODE(&session->global_hlist);
 
-		/* Inherit debug options from tunnel */
-		session->debug = tunnel->debug;
-
 		if (cfg) {
 			session->pwtype = cfg->pw_type;
-			session->debug = cfg->debug;
 			session->send_seq = cfg->send_seq;
 			session->recv_seq = cfg->recv_seq;
 			session->lns_mode = cfg->lns_mode;