1 files changed, 348 insertions, 177 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 89ff8c67943..32b2155e7ab 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -18,6 +18,8 @@
  * published by the Free Software Foundation.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/string.h>
 #include <linux/list.h>
@@ -53,6 +55,10 @@
 #include <net/inet_common.h>
 #include <net/xfrm.h>
 #include <net/protocol.h>
+#include <net/inet6_connection_sock.h>
+#include <net/inet_ecn.h>
+#include <net/ip6_route.h>
+#include <net/ip6_checksum.h>
 
 #include <asm/byteorder.h>
 #include <linux/atomic.h>
@@ -82,12 +88,6 @@
 /* Default trace flags */
 #define L2TP_DEFAULT_DEBUG_FLAGS	0
 
-#define PRINTK(_mask, _type, _lvl, _fmt, args...)			\
-	do {								\
-		if ((_mask) & (_type))					\
-			printk(_lvl "L2TP: " _fmt, ##args);		\
-	} while (0)
-
 /* Private data stored for received packets in the skb.
  */
 struct l2tp_skb_cb {
@@ -137,14 +137,20 @@ static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel)
 		l2tp_tunnel_free(tunnel);
 }
 #ifdef L2TP_REFCNT_DEBUG
-#define l2tp_tunnel_inc_refcount(_t) do { \
-		printk(KERN_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 { \
-		printk(KERN_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)
+#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)
@@ -326,16 +332,20 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk
 	struct sk_buff *skbp;
 	struct sk_buff *tmp;
 	u32 ns = L2TP_SKB_CB(skb)->ns;
+	struct l2tp_stats *sstats;
 
 	spin_lock_bh(&session->reorder_q.lock);
+	sstats = &session->stats;
 	skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
 		if (L2TP_SKB_CB(skbp)->ns > ns) {
 			__skb_queue_before(&session->reorder_q, skbp, skb);
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-			       "%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));
-			session->stats.rx_oos_packets++;
+			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));
+			u64_stats_update_begin(&sstats->syncp);
+			sstats->rx_oos_packets++;
+			u64_stats_update_end(&sstats->syncp);
 			goto out;
 		}
 	}
@@ -352,16 +362,23 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
 {
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	int length = L2TP_SKB_CB(skb)->length;
+	struct l2tp_stats *tstats, *sstats;
 
 	/* We're about to requeue the skb, so return resources
 	 * to its current owner (a socket receive buffer).
 	 */
 	skb_orphan(skb);
 
-	tunnel->stats.rx_packets++;
-	tunnel->stats.rx_bytes += length;
-	session->stats.rx_packets++;
-	session->stats.rx_bytes += length;
+	tstats = &tunnel->stats;
+	u64_stats_update_begin(&tstats->syncp);
+	sstats = &session->stats;
+	u64_stats_update_begin(&sstats->syncp);
+	tstats->rx_packets++;
+	tstats->rx_bytes += length;
+	sstats->rx_packets++;
+	sstats->rx_bytes += length;
+	u64_stats_update_end(&tstats->syncp);
+	u64_stats_update_end(&sstats->syncp);
 
 	if (L2TP_SKB_CB(skb)->has_seq) {
 		/* Bump our Nr */
@@ -371,8 +388,8 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
 		else
 			session->nr &= 0xffffff;
 
-		PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-		       "%s: updated nr to %hu\n", session->name, session->nr);
+		l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n",
+			 session->name, session->nr);
 	}
 
 	/* call private receive handler */
@@ -392,6 +409,7 @@ static void l2tp_recv_dequeue(struct l2tp_session *session)
 {
 	struct sk_buff *skb;
 	struct sk_buff *tmp;
+	struct l2tp_stats *sstats;
 
 	/* If the pkt at the head of the queue has the nr that we
 	 * expect to send up next, dequeue it and any other
@@ -399,16 +417,19 @@ static void l2tp_recv_dequeue(struct l2tp_session *session)
 	 */
 start:
 	spin_lock_bh(&session->reorder_q.lock);
+	sstats = &session->stats;
 	skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
 		if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) {
-			session->stats.rx_seq_discards++;
-			session->stats.rx_errors++;
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-			       "%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));
+			u64_stats_update_begin(&sstats->syncp);
+			sstats->rx_seq_discards++;
+			sstats->rx_errors++;
+			u64_stats_update_end(&sstats->syncp);
+			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));
+			session->reorder_skip = 1;
 			__skb_unlink(skb, &session->reorder_q);
 			kfree_skb(skb);
 			if (session->deref)
@@ -417,13 +438,20 @@ start:
 		}
 
 		if (L2TP_SKB_CB(skb)->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;
+			}
 			if (L2TP_SKB_CB(skb)->ns != session->nr) {
-				PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-				       "%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));
+				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));
 				goto out;
 			}
 		}
@@ -446,21 +474,43 @@ static inline int l2tp_verify_udp_checksum(struct sock *sk,
 {
 	struct udphdr *uh = udp_hdr(skb);
 	u16 ulen = ntohs(uh->len);
-	struct inet_sock *inet;
 	__wsum psum;
 
-	if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check)
+	if (sk->sk_no_check || skb_csum_unnecessary(skb))
 		return 0;
 
-	inet = inet_sk(sk);
-	psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr, ulen,
-				  IPPROTO_UDP, 0);
-
-	if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
-	    !csum_fold(csum_add(psum, skb->csum)))
-		return 0;
-
-	skb->csum = psum;
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == PF_INET6) {
+		if (!uh->check) {
+			LIMIT_NETDEBUG(KERN_INFO "L2TP: IPv6: checksum is 0\n");
+			return 1;
+		}
+		if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    !csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+				     &ipv6_hdr(skb)->daddr, ulen,
+				     IPPROTO_UDP, skb->csum)) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			return 0;
+		}
+		skb->csum = ~csum_unfold(csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
+							 &ipv6_hdr(skb)->daddr,
+							 skb->len, IPPROTO_UDP,
+							 0));
+	} else
+#endif
+	{
+		struct inet_sock *inet;
+		if (!uh->check)
+			return 0;
+		inet = inet_sk(sk);
+		psum = csum_tcpudp_nofold(inet->inet_saddr, inet->inet_daddr,
+					  ulen, IPPROTO_UDP, 0);
+
+		if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    !csum_fold(csum_add(psum, skb->csum)))
+			return 0;
+		skb->csum = psum;
+	}
 
 	return __skb_checksum_complete(skb);
 }
@@ -532,6 +582,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	int offset;
 	u32 ns, nr;
+	struct l2tp_stats *sstats = &session->stats;
 
 	/* The ref count is increased since we now hold a pointer to
 	 * the session. Take care to decrement the refcnt when exiting
@@ -544,10 +595,13 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 	/* Parse and check optional cookie */
 	if (session->peer_cookie_len > 0) {
 		if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) {
-			PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO,
-			       "%s: cookie mismatch (%u/%u). Discarding.\n",
-			       tunnel->name, tunnel->tunnel_id, session->session_id);
-			session->stats.rx_cookie_discards++;
+			l2tp_info(tunnel, L2TP_MSG_DATA,
+				  "%s: cookie mismatch (%u/%u). Discarding.\n",
+				  tunnel->name, tunnel->tunnel_id,
+				  session->session_id);
+			u64_stats_update_begin(&sstats->syncp);
+			sstats->rx_cookie_discards++;
+			u64_stats_update_end(&sstats->syncp);
 			goto discard;
 		}
 		ptr += session->peer_cookie_len;
@@ -573,9 +627,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 			L2TP_SKB_CB(skb)->ns = ns;
 			L2TP_SKB_CB(skb)->has_seq = 1;
 
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-			       "%s: recv data ns=%u, nr=%u, session nr=%u\n",
-			       session->name, ns, nr, session->nr);
+			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);
@@ -587,9 +641,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 			L2TP_SKB_CB(skb)->ns = ns;
 			L2TP_SKB_CB(skb)->has_seq = 1;
 
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-			       "%s: recv data ns=%u, session nr=%u\n",
-			       session->name, ns, session->nr);
+			l2tp_dbg(session, L2TP_MSG_SEQ,
+				 "%s: recv data ns=%u, session nr=%u\n",
+				 session->name, ns, session->nr);
 		}
 	}
 
@@ -602,9 +656,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		 * configure it so.
 		 */
 		if ((!session->lns_mode) && (!session->send_seq)) {
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO,
-			       "%s: requested to enable seq numbers by LNS\n",
-			       session->name);
+			l2tp_info(session, L2TP_MSG_SEQ,
+				  "%s: requested to enable seq numbers by LNS\n",
+				  session->name);
 			session->send_seq = -1;
 			l2tp_session_set_header_len(session, tunnel->version);
 		}
@@ -613,10 +667,12 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 		 * If user has configured mandatory sequence numbers, discard.
 		 */
 		if (session->recv_seq) {
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING,
-			       "%s: recv data has no seq numbers when required. "
-			       "Discarding\n", session->name);
-			session->stats.rx_seq_discards++;
+			l2tp_warn(session, L2TP_MSG_SEQ,
+				  "%s: recv data has no seq numbers when required. Discarding.\n",
+				  session->name);
+			u64_stats_update_begin(&sstats->syncp);
+			sstats->rx_seq_discards++;
+			u64_stats_update_end(&sstats->syncp);
 			goto discard;
 		}
 
@@ -626,16 +682,18 @@ 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)) {
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_INFO,
-			       "%s: requested to disable seq numbers by LNS\n",
-			       session->name);
+			l2tp_info(session, L2TP_MSG_SEQ,
+				  "%s: requested to disable seq numbers by LNS\n",
+				  session->name);
 			session->send_seq = 0;
 			l2tp_session_set_header_len(session, tunnel->version);
 		} else if (session->send_seq) {
-			PRINTK(session->debug, L2TP_MSG_SEQ, KERN_WARNING,
-			       "%s: recv data has no seq numbers when required. "
-			       "Discarding\n", session->name);
-			session->stats.rx_seq_discards++;
+			l2tp_warn(session, L2TP_MSG_SEQ,
+				  "%s: recv data has no seq numbers when required. Discarding.\n",
+				  session->name);
+			u64_stats_update_begin(&sstats->syncp);
+			sstats->rx_seq_discards++;
+			u64_stats_update_end(&sstats->syncp);
 			goto discard;
 		}
 	}
@@ -689,13 +747,14 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 			 * packets
 			 */
 			if (L2TP_SKB_CB(skb)->ns != session->nr) {
-				session->stats.rx_seq_discards++;
-				PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-				       "%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));
+				u64_stats_update_begin(&sstats->syncp);
+				sstats->rx_seq_discards++;
+				u64_stats_update_end(&sstats->syncp);
+				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));
 				goto discard;
 			}
 			skb_queue_tail(&session->reorder_q, skb);
@@ -716,7 +775,9 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
 	return;
 
 discard:
-	session->stats.rx_errors++;
+	u64_stats_update_begin(&sstats->syncp);
+	sstats->rx_errors++;
+	u64_stats_update_end(&sstats->syncp);
 	kfree_skb(skb);
 
 	if (session->deref)
@@ -739,9 +800,9 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 	unsigned char *ptr, *optr;
 	u16 hdrflags;
 	u32 tunnel_id, session_id;
-	int offset;
 	u16 version;
 	int length;
+	struct l2tp_stats *tstats;
 
 	if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb))
 		goto discard_bad_csum;
@@ -751,8 +812,9 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 
 	/* Short packet? */
 	if (!pskb_may_pull(skb, L2TP_HDR_SIZE_SEQ)) {
-		PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO,
-		       "%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
+		l2tp_info(tunnel, L2TP_MSG_DATA,
+			  "%s: recv short packet (len=%d)\n",
+			  tunnel->name, skb->len);
 		goto error;
 	}
 
@@ -762,14 +824,8 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 		if (!pskb_may_pull(skb, length))
 			goto error;
 
-		printk(KERN_DEBUG "%s: recv: ", tunnel->name);
-
-		offset = 0;
-		do {
-			printk(" %02X", skb->data[offset]);
-		} while (++offset < length);
-
-		printk("\n");
+		pr_debug("%s: recv\n", tunnel->name);
+		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
 	}
 
 	/* Point to L2TP header */
@@ -781,9 +837,9 @@ 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) {
-		PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO,
-		       "%s: recv protocol version mismatch: got %d expected %d\n",
-		       tunnel->name, version, tunnel->version);
+		l2tp_info(tunnel, L2TP_MSG_DATA,
+			  "%s: recv protocol version mismatch: got %d expected %d\n",
+			  tunnel->name, version, tunnel->version);
 		goto error;
 	}
 
@@ -792,8 +848,9 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 
 	/* If type is control packet, it is handled by userspace. */
 	if (hdrflags & L2TP_HDRFLAG_T) {
-		PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG,
-		       "%s: recv control packet, len=%d\n", tunnel->name, length);
+		l2tp_dbg(tunnel, L2TP_MSG_DATA,
+			 "%s: recv control packet, len=%d\n",
+			 tunnel->name, length);
 		goto error;
 	}
 
@@ -821,9 +878,9 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 	session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id);
 	if (!session || !session->recv_skb) {
 		/* Not found? Pass to userspace to deal with */
-		PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO,
-		       "%s: no session found (%u/%u). Passing up.\n",
-		       tunnel->name, tunnel_id, session_id);
+		l2tp_info(tunnel, L2TP_MSG_DATA,
+			  "%s: no session found (%u/%u). Passing up.\n",
+			  tunnel->name, tunnel_id, session_id);
 		goto error;
 	}
 
@@ -834,7 +891,10 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 discard_bad_csum:
 	LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name);
 	UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0);
-	tunnel->stats.rx_errors++;
+	tstats = &tunnel->stats;
+	u64_stats_update_begin(&tstats->syncp);
+	tstats->rx_errors++;
+	u64_stats_update_end(&tstats->syncp);
 	kfree_skb(skb);
 
 	return 0;
@@ -860,8 +920,8 @@ int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	if (tunnel == NULL)
 		goto pass_up;
 
-	PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_DEBUG,
-	       "%s: received %d bytes\n", tunnel->name, skb->len);
+	l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n",
+		 tunnel->name, skb->len);
 
 	if (l2tp_udp_recv_core(tunnel, skb, tunnel->recv_payload_hook))
 		goto pass_up_put;
@@ -903,8 +963,8 @@ static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf)
 		*bufp++ = 0;
 		session->ns++;
 		session->ns &= 0xffff;
-		PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-		       "%s: updated ns to %u\n", session->name, session->ns);
+		l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n",
+			 session->name, session->ns);
 	}
 
 	return bufp - optr;
@@ -940,8 +1000,9 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf)
 				l2h = 0x40000000 | session->ns;
 				session->ns++;
 				session->ns &= 0xffffff;
-				PRINTK(session->debug, L2TP_MSG_SEQ, KERN_DEBUG,
-				       "%s: updated ns to %u\n", session->name, session->ns);
+				l2tp_dbg(session, L2TP_MSG_SEQ,
+					 "%s: updated ns to %u\n",
+					 session->name, session->ns);
 			}
 
 			*((__be32 *) bufp) = htonl(l2h);
@@ -960,46 +1021,50 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
 	struct l2tp_tunnel *tunnel = session->tunnel;
 	unsigned int len = skb->len;
 	int error;
+	struct l2tp_stats *tstats, *sstats;
 
 	/* Debug */
 	if (session->send_seq)
-		PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG,
-		       "%s: send %Zd bytes, ns=%u\n", session->name,
-		       data_len, session->ns - 1);
+		l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes, ns=%u\n",
+			 session->name, data_len, session->ns - 1);
 	else
-		PRINTK(session->debug, L2TP_MSG_DATA, KERN_DEBUG,
-		       "%s: send %Zd bytes\n", session->name, data_len);
+		l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %Zd bytes\n",
+			 session->name, data_len);
 
 	if (session->debug & L2TP_MSG_DATA) {
-		int i;
 		int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0;
 		unsigned char *datap = skb->data + uhlen;
 
-		printk(KERN_DEBUG "%s: xmit:", session->name);
-		for (i = 0; i < (len - uhlen); i++) {
-			printk(" %02X", *datap++);
-			if (i == 31) {
-				printk(" ...");
-				break;
-			}
-		}
-		printk("\n");
+		pr_debug("%s: xmit\n", session->name);
+		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET,
+				     datap, min_t(size_t, 32, len - uhlen));
 	}
 
 	/* Queue the packet to IP for output */
 	skb->local_df = 1;
-	error = ip_queue_xmit(skb, fl);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (skb->sk->sk_family == PF_INET6)
+		error = inet6_csk_xmit(skb, NULL);
+	else
+#endif
+		error = ip_queue_xmit(skb, fl);
 
 	/* Update stats */
+	tstats = &tunnel->stats;
+	u64_stats_update_begin(&tstats->syncp);
+	sstats = &session->stats;
+	u64_stats_update_begin(&sstats->syncp);
 	if (error >= 0) {
-		tunnel->stats.tx_packets++;
-		tunnel->stats.tx_bytes += len;
-		session->stats.tx_packets++;
-		session->stats.tx_bytes += len;
+		tstats->tx_packets++;
+		tstats->tx_bytes += len;
+		sstats->tx_packets++;
+		sstats->tx_bytes += len;
 	} else {
-		tunnel->stats.tx_errors++;
-		session->stats.tx_errors++;
+		tstats->tx_errors++;
+		sstats->tx_errors++;
 	}
+	u64_stats_update_end(&tstats->syncp);
+	u64_stats_update_end(&sstats->syncp);
 
 	return 0;
 }
@@ -1021,6 +1086,31 @@ static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
 	skb->destructor = l2tp_sock_wfree;
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
+static void l2tp_xmit_ipv6_csum(struct sock *sk, struct sk_buff *skb,
+				int udp_len)
+{
+	struct ipv6_pinfo *np = inet6_sk(sk);
+	struct udphdr *uh = udp_hdr(skb);
+
+	if (!skb_dst(skb) || !skb_dst(skb)->dev ||
+	    !(skb_dst(skb)->dev->features & NETIF_F_IPV6_CSUM)) {
+		__wsum csum = skb_checksum(skb, 0, udp_len, 0);
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		uh->check = csum_ipv6_magic(&np->saddr, &np->daddr, udp_len,
+					    IPPROTO_UDP, csum);
+		if (uh->check == 0)
+			uh->check = CSUM_MANGLED_0;
+	} else {
+		skb->ip_summed = CHECKSUM_PARTIAL;
+		skb->csum_start = skb_transport_header(skb) - skb->head;
+		skb->csum_offset = offsetof(struct udphdr, check);
+		uh->check = ~csum_ipv6_magic(&np->saddr, &np->daddr,
+					     udp_len, IPPROTO_UDP, 0);
+	}
+}
+#endif
+
 /* If caller requires the skb to have a ppp header, the header must be
  * inserted in the skb data before calling this function.
  */
@@ -1089,6 +1179,11 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len
 		uh->check = 0;
 
 		/* Calculate UDP checksum if configured to do so */
+#if IS_ENABLED(CONFIG_IPV6)
+		if (sk->sk_family == PF_INET6)
+			l2tp_xmit_ipv6_csum(sk, skb, udp_len);
+		else
+#endif
 		if (sk->sk_no_check == UDP_CSUM_NOXMIT)
 			skb->ip_summed = CHECKSUM_NONE;
 		else if ((skb_dst(skb) && skb_dst(skb)->dev) &&
@@ -1141,8 +1236,7 @@ static void l2tp_tunnel_destruct(struct sock *sk)
 	if (tunnel == NULL)
 		goto end;
 
-	PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO,
-	       "%s: closing...\n", tunnel->name);
+	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name);
 
 	/* Close all sessions */
 	l2tp_tunnel_closeall(tunnel);
@@ -1184,8 +1278,8 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 
 	BUG_ON(tunnel == NULL);
 
-	PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO,
-	       "%s: closing all sessions...\n", tunnel->name);
+	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n",
+		  tunnel->name);
 
 	write_lock_bh(&tunnel->hlist_lock);
 	for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
@@ -1193,8 +1287,8 @@ again:
 		hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
 			session = hlist_entry(walk, struct l2tp_session, hlist);
 
-			PRINTK(session->debug, L2TP_MSG_CONTROL, KERN_INFO,
-			       "%s: closing session\n", session->name);
+			l2tp_info(session, L2TP_MSG_CONTROL,
+				  "%s: closing session\n", session->name);
 
 			hlist_del_init(&session->hlist);
 
@@ -1247,8 +1341,7 @@ static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel)
 	BUG_ON(atomic_read(&tunnel->ref_count) != 0);
 	BUG_ON(tunnel->sock != NULL);
 
-	PRINTK(tunnel->debug, L2TP_MSG_CONTROL, KERN_INFO,
-	       "%s: free...\n", tunnel->name);
+	l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name);
 
 	/* Remove from tunnel list */
 	spin_lock_bh(&pn->l2tp_tunnel_list_lock);
@@ -1268,31 +1361,69 @@ static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2t
 {
 	int err = -EINVAL;
 	struct sockaddr_in udp_addr;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct sockaddr_in6 udp6_addr;
+	struct sockaddr_l2tpip6 ip6_addr;
+#endif
 	struct sockaddr_l2tpip ip_addr;
 	struct socket *sock = NULL;
 
 	switch (cfg->encap) {
 	case L2TP_ENCAPTYPE_UDP:
-		err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp);
-		if (err < 0)
-			goto out;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (cfg->local_ip6 && cfg->peer_ip6) {
+			err = sock_create(AF_INET6, SOCK_DGRAM, 0, sockp);
+			if (err < 0)
+				goto out;
 
-		sock = *sockp;
+			sock = *sockp;
 
-		memset(&udp_addr, 0, sizeof(udp_addr));
-		udp_addr.sin_family = AF_INET;
-		udp_addr.sin_addr = cfg->local_ip;
-		udp_addr.sin_port = htons(cfg->local_udp_port);
-		err = kernel_bind(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr));
-		if (err < 0)
-			goto out;
+			memset(&udp6_addr, 0, sizeof(udp6_addr));
+			udp6_addr.sin6_family = AF_INET6;
+			memcpy(&udp6_addr.sin6_addr, cfg->local_ip6,
+			       sizeof(udp6_addr.sin6_addr));
+			udp6_addr.sin6_port = htons(cfg->local_udp_port);
+			err = kernel_bind(sock, (struct sockaddr *) &udp6_addr,
+					  sizeof(udp6_addr));
+			if (err < 0)
+				goto out;
 
-		udp_addr.sin_family = AF_INET;
-		udp_addr.sin_addr = cfg->peer_ip;
-		udp_addr.sin_port = htons(cfg->peer_udp_port);
-		err = kernel_connect(sock, (struct sockaddr *) &udp_addr, sizeof(udp_addr), 0);
-		if (err < 0)
-			goto out;
+			udp6_addr.sin6_family = AF_INET6;
+			memcpy(&udp6_addr.sin6_addr, cfg->peer_ip6,
+			       sizeof(udp6_addr.sin6_addr));
+			udp6_addr.sin6_port = htons(cfg->peer_udp_port);
+			err = kernel_connect(sock,
+					     (struct sockaddr *) &udp6_addr,
+					     sizeof(udp6_addr), 0);
+			if (err < 0)
+				goto out;
+		} else
+#endif
+		{
+			err = sock_create(AF_INET, SOCK_DGRAM, 0, sockp);
+			if (err < 0)
+				goto out;
+
+			sock = *sockp;
+
+			memset(&udp_addr, 0, sizeof(udp_addr));
+			udp_addr.sin_family = AF_INET;
+			udp_addr.sin_addr = cfg->local_ip;
+			udp_addr.sin_port = htons(cfg->local_udp_port);
+			err = kernel_bind(sock, (struct sockaddr *) &udp_addr,
+					  sizeof(udp_addr));
+			if (err < 0)
+				goto out;
+
+			udp_addr.sin_family = AF_INET;
+			udp_addr.sin_addr = cfg->peer_ip;
+			udp_addr.sin_port = htons(cfg->peer_udp_port);
+			err = kernel_connect(sock,
+					     (struct sockaddr *) &udp_addr,
+					     sizeof(udp_addr), 0);
+			if (err < 0)
+				goto out;
+		}
 
 		if (!cfg->use_udp_checksums)
 			sock->sk->sk_no_check = UDP_CSUM_NOXMIT;
@@ -1300,27 +1431,61 @@ static int l2tp_tunnel_sock_create(u32 tunnel_id, u32 peer_tunnel_id, struct l2t
 		break;
 
 	case L2TP_ENCAPTYPE_IP:
-		err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP, sockp);
-		if (err < 0)
-			goto out;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (cfg->local_ip6 && cfg->peer_ip6) {
+			err = sock_create(AF_INET6, SOCK_DGRAM, IPPROTO_L2TP,
+					  sockp);
+			if (err < 0)
+				goto out;
 
-		sock = *sockp;
+			sock = *sockp;
 
-		memset(&ip_addr, 0, sizeof(ip_addr));
-		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, sizeof(ip_addr));
-		if (err < 0)
-			goto out;
+			memset(&ip6_addr, 0, sizeof(ip6_addr));
+			ip6_addr.l2tp_family = AF_INET6;
+			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,
+					  sizeof(ip6_addr));
+			if (err < 0)
+				goto out;
 
-		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, sizeof(ip_addr), 0);
-		if (err < 0)
-			goto out;
+			ip6_addr.l2tp_family = AF_INET6;
+			memcpy(&ip6_addr.l2tp_addr, cfg->peer_ip6,
+			       sizeof(ip6_addr.l2tp_addr));
+			ip6_addr.l2tp_conn_id = peer_tunnel_id;
+			err = kernel_connect(sock,
+					     (struct sockaddr *) &ip6_addr,
+					     sizeof(ip6_addr), 0);
+			if (err < 0)
+				goto out;
+		} else
+#endif
+		{
+			err = sock_create(AF_INET, SOCK_DGRAM, IPPROTO_L2TP,
+					  sockp);
+			if (err < 0)
+				goto out;
+
+			sock = *sockp;
+
+			memset(&ip_addr, 0, sizeof(ip_addr));
+			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,
+					  sizeof(ip_addr));
+			if (err < 0)
+				goto out;
 
+			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,
+					     sizeof(ip_addr), 0);
+			if (err < 0)
+				goto out;
+		}
 		break;
 
 	default:
@@ -1357,7 +1522,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 		err = -EBADF;
 		sock = sockfd_lookup(fd, &err);
 		if (!sock) {
-			printk(KERN_ERR "tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
+			pr_err("tunl %hu: sockfd_lookup(fd=%d) returned %d\n",
 			       tunnel_id, fd, err);
 			goto err;
 		}
@@ -1373,7 +1538,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	case L2TP_ENCAPTYPE_UDP:
 		err = -EPROTONOSUPPORT;
 		if (sk->sk_protocol != IPPROTO_UDP) {
-			printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
+			pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
 			       tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
 			goto err;
 		}
@@ -1381,7 +1546,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 	case L2TP_ENCAPTYPE_IP:
 		err = -EPROTONOSUPPORT;
 		if (sk->sk_protocol != IPPROTO_L2TP) {
-			printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
+			pr_err("tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
 			       tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP);
 			goto err;
 		}
@@ -1424,6 +1589,12 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
 		/* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
 		udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP;
 		udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv;
+#if IS_ENABLED(CONFIG_IPV6)
+		if (sk->sk_family == PF_INET6)
+			udpv6_encap_enable();
+		else
+#endif
+		udp_encap_enable();
 	}
 
 	sk->sk_user_data = tunnel;
@@ -1577,7 +1748,7 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn
 
 		session->session_id = session_id;
 		session->peer_session_id = peer_session_id;
-		session->nr = 1;
+		session->nr = 0;
 
 		sprintf(&session->name[0], "sess %u/%u",
 			tunnel->tunnel_id, session->session_id);
@@ -1683,7 +1854,7 @@ static int __init l2tp_init(void)
 	if (rc)
 		goto out;
 
-	printk(KERN_INFO "L2TP core driver, %s\n", L2TP_DRV_VERSION);
+	pr_info("L2TP core driver, %s\n", L2TP_DRV_VERSION);
 
 out:
 	return rc;