Merge branch 'l2tp-replace-custom-logging-code-with-tracepoints'

Tom Parkin says:

====================
l2tp: replace custom logging code with tracepoints

The l2tp subsystem implemented custom logging macros for debugging
purposes which were controlled using a set of debugging flags in each
tunnel and session structure.

A more standard and easier-to-use approach is to use tracepoints.

This patchset refactors l2tp to:

 * remove excessive logging
 * tweak useful log messages to use the standard pr_* calls for logging
   rather than the l2tp wrappers
 * replace debug-level logging with tracepoints
 * add tracepoints for capturing tunnel and session lifetime events

I note that checkpatch.pl warns about the layout of code in the
newly-added file net/l2tp/trace.h.  When adding this file I followed the
example(s) of other tracepoint files in the net/ subtree since it seemed
preferable to adhere to the prevailing style rather than follow
checkpatch.pl's advice in this instance.  If that's the wrong
approach please let me know.

v1 -> v2

 * Fix up a build warning found by the kernel test robot
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/l2tp.rst

@@ -455,31 +455,16 @@ l2tp help`` for more information.
 Debugging
 ---------
 
-The L2TP subsystem offers a debug scheme where kernel trace messages
-may be optionally enabled per tunnel and per session. Care is needed
-when debugging a live system since the messages are not rate-limited
-and a busy system could be swamped. Userspace uses setsockopt on the
-PPPoX socket to set a debug mask, or ``L2TP_ATTR_DEBUG`` in netlink
-Create and Modify commands.
+The L2TP subsystem offers a range of debugging interfaces through the
+debugfs filesystem.
 
-The following debug mask bits are defined:-
-
-================  ==============================
-L2TP_MSG_DEBUG    verbose debug (if compiled in)
-L2TP_MSG_CONTROL  userspace - kernel interface
-L2TP_MSG_SEQ      sequence numbers handling
-L2TP_MSG_DATA     data packets
-================  ==============================
-
-Sessions inherit default debug flags from the parent tunnel.
-
-If enabled, files under a l2tp debugfs directory can be used to dump
-kernel state about L2TP tunnels and sessions. To access it, the
-debugfs filesystem must first be mounted::
+To access these interfaces, the debugfs filesystem must first be mounted::
 
     # mount -t debugfs debugfs /debug
 
-Files under the l2tp directory can then be accessed::
+Files under the l2tp directory can then be accessed, providing a summary
+of the current population of tunnel and session contexts existing in the
+kernel::
 
     # cat /debug/l2tp/tunnels
 
@@ -488,8 +473,14 @@ state information because the file format is subject to change. It is
 implemented to provide extra debug information to help diagnose
 problems. Applications should instead use the netlink API.
 
-/proc/net/pppol2tp is also provided for backwards compatibility with
-the original pppol2tp code. It lists information about L2TPv2
+In addition the L2TP subsystem implements tracepoints using the standard
+kernel event tracing API.  The available L2TP events can be reviewed as
+follows::
+
+    # find /debug/tracing/events/l2tp
+
+Finally, /proc/net/pppol2tp is also provided for backwards compatibility
+with the original pppol2tp code. It lists information about L2TPv2
 tunnels and sessions only. Its use is discouraged.
 
 Internal Implementation

include/uapi/linux/if_pppol2tp.h

@@ -75,7 +75,7 @@ struct pppol2tpv3in6_addr {
 };
 
 /* Socket options:
- * DEBUG	- bitmask of debug message categories
+ * DEBUG	- bitmask of debug message categories (not used)
  * SENDSEQ	- 0 => don't send packets with sequence numbers
  *		  1 => send packets with sequence numbers
  * RECVSEQ	- 0 => receive packet sequence numbers are optional

include/uapi/linux/l2tp.h

@@ -108,7 +108,7 @@ enum {
 	L2TP_ATTR_VLAN_ID,		/* u16 (not used) */
 	L2TP_ATTR_COOKIE,		/* 0, 4 or 8 bytes */
 	L2TP_ATTR_PEER_COOKIE,		/* 0, 4 or 8 bytes */
-	L2TP_ATTR_DEBUG,		/* u32, enum l2tp_debug_flags */
+	L2TP_ATTR_DEBUG,		/* u32, enum l2tp_debug_flags (not used) */
 	L2TP_ATTR_RECV_SEQ,		/* u8 */
 	L2TP_ATTR_SEND_SEQ,		/* u8 */
 	L2TP_ATTR_LNS_MODE,		/* u8 */
@@ -177,7 +177,9 @@ enum l2tp_seqmode {
 };
 
 /**
- * enum l2tp_debug_flags - debug message categories for L2TP tunnels/sessions
+ * enum l2tp_debug_flags - debug message categories for L2TP tunnels/sessions.
+ *
+ * Unused.
  *
  * @L2TP_MSG_DEBUG: verbose debug (if compiled in)
  * @L2TP_MSG_CONTROL: userspace - kernel interface

net/l2tp/Makefile

@@ -5,6 +5,8 @@
 
 obj-$(CONFIG_L2TP) += l2tp_core.o
 
+CFLAGS_l2tp_core.o += -I$(src)
+
 # Build l2tp as modules if L2TP is M
 obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_PPPOL2TP)) += l2tp_ppp.o
 obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_IP)) += l2tp_ip.o

net/l2tp/l2tp_core.h

@@ -51,7 +51,6 @@ struct l2tp_session_cfg {
 	unsigned int		lns_mode:1;	/* behave as LNS?
 						 * LAC enables sequence numbers under LNS control.
 						 */
-	int			debug;		/* bitmask of debug message categories */
 	u16			l2specific_type; /* Layer 2 specific type */
 	u8			cookie[8];	/* optional cookie */
 	int			cookie_len;	/* 0, 4 or 8 bytes */
@@ -66,6 +65,7 @@ struct l2tp_session_cfg {
  * Is linked into a per-tunnel session hashlist; and in the case of an L2TPv3 session into
  * an additional per-net ("global") hashlist.
  */
+#define L2TP_SESSION_NAME_MAX 32
 struct l2tp_session {
 	int			magic;		/* should be L2TP_SESSION_MAGIC */
 	long			dead;
@@ -90,14 +90,13 @@ struct l2tp_session {
 	struct hlist_node	hlist;		/* hash list node */
 	refcount_t		ref_count;
 
-	char			name[32];	/* for logging */
+	char			name[L2TP_SESSION_NAME_MAX]; /* for logging */
 	char			ifname[IFNAMSIZ];
 	unsigned int		recv_seq:1;	/* expect receive packets with sequence numbers? */
 	unsigned int		send_seq:1;	/* send packets with sequence numbers? */
 	unsigned int		lns_mode:1;	/* behave as LNS?
 						 * LAC enables sequence numbers under LNS control.
 						 */
-	int			debug;		/* bitmask of debug message categories */
 	int			reorder_timeout; /* configured reorder timeout (in jiffies) */
 	int			reorder_skip;	/* set if skip to next nr */
 	enum l2tp_pwtype	pwtype;
@@ -131,7 +130,6 @@ struct l2tp_session {
 
 /* L2TP tunnel configuration */
 struct l2tp_tunnel_cfg {
-	int			debug;		/* bitmask of debug message categories */
 	enum l2tp_encap_type	encap;
 
 	/* Used only for kernel-created sockets */
@@ -154,6 +152,7 @@ struct l2tp_tunnel_cfg {
  * Maintains a hashlist of sessions belonging to the tunnel instance.
  * Is linked into a per-net list of tunnels.
  */
+#define L2TP_TUNNEL_NAME_MAX 20
 struct l2tp_tunnel {
 	int			magic;		/* Should be L2TP_TUNNEL_MAGIC */
 
@@ -170,8 +169,7 @@ struct l2tp_tunnel {
 	u32			peer_tunnel_id;
 	int			version;	/* 2=>L2TPv2, 3=>L2TPv3 */
 
-	char			name[20];	/* for logging */
-	int			debug;		/* bitmask of debug message categories */
+	char			name[L2TP_TUNNEL_NAME_MAX]; /* for logging */
 	enum l2tp_encap_type	encap;
 	struct l2tp_stats	stats;
 
@@ -337,19 +335,6 @@ static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, str
 	return 0;
 }
 
-#define l2tp_printk(ptr, type, func, fmt, ...)				\
-do {									\
-	if (((ptr)->debug) & (type))					\
-		func(fmt, ##__VA_ARGS__);				\
-} while (0)
-
-#define l2tp_warn(ptr, type, fmt, ...)					\
-	l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__)
-#define l2tp_info(ptr, type, fmt, ...)					\
-	l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__)
-#define l2tp_dbg(ptr, type, fmt, ...)					\
-	l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__)
-
 #define MODULE_ALIAS_L2TP_PWTYPE(type) \
 	MODULE_ALIAS("net-l2tp-type-" __stringify(type))
 

net/l2tp/l2tp_debugfs.c

@@ -167,7 +167,7 @@ static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
 		   tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
 		   refcount_read(&tunnel->ref_count));
 	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
-		   tunnel->debug,
+		   0,
 		   atomic_long_read(&tunnel->stats.tx_packets),
 		   atomic_long_read(&tunnel->stats.tx_bytes),
 		   atomic_long_read(&tunnel->stats.tx_errors),
@@ -192,7 +192,7 @@ static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
 		   session->recv_seq ? 'R' : '-',
 		   session->send_seq ? 'S' : '-',
 		   session->lns_mode ? "LNS" : "LAC",
-		   session->debug,
+		   0,
 		   jiffies_to_msecs(session->reorder_timeout));
 	seq_printf(m, "   offset 0 l2specific %hu/%hu\n",
 		   session->l2specific_type, l2tp_get_l2specific_len(session));

net/l2tp/l2tp_eth.c

@@ -128,17 +128,6 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb,
 	struct net_device *dev;
 	struct l2tp_eth *priv;
 
-	if (session->debug & L2TP_MSG_DATA) {
-		unsigned int length;
-
-		length = min(32u, skb->len);
-		if (!pskb_may_pull(skb, length))
-			goto error;
-
-		pr_debug("%s: eth recv\n", session->name);
-		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length);
-	}
-
 	if (!pskb_may_pull(skb, ETH_HLEN))
 		goto error;
 

net/l2tp/l2tp_ip.c

@@ -118,7 +118,6 @@ static int l2tp_ip_recv(struct sk_buff *skb)
 	struct l2tp_session *session;
 	struct l2tp_tunnel *tunnel = NULL;
 	struct iphdr *iph;
-	int length;
 
 	if (!pskb_may_pull(skb, 4))
 		goto discard;
@@ -147,20 +146,6 @@ static int l2tp_ip_recv(struct sk_buff *skb)
 	if (!tunnel)
 		goto discard_sess;
 
-	/* Trace packet contents, if enabled */
-	if (tunnel->debug & L2TP_MSG_DATA) {
-		length = min(32u, skb->len);
-		if (!pskb_may_pull(skb, length))
-			goto discard_sess;
-
-		/* Point to L2TP header */
-		optr = skb->data;
-		ptr = skb->data;
-		ptr += 4;
-		pr_debug("%s: ip recv\n", tunnel->name);
-		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
-	}
-
 	if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
 		goto discard_sess;
 

net/l2tp/l2tp_ip6.c

@@ -131,7 +131,6 @@ static int l2tp_ip6_recv(struct sk_buff *skb)
 	struct l2tp_session *session;
 	struct l2tp_tunnel *tunnel = NULL;
 	struct ipv6hdr *iph;
-	int length;
 
 	if (!pskb_may_pull(skb, 4))
 		goto discard;
@@ -160,20 +159,6 @@ static int l2tp_ip6_recv(struct sk_buff *skb)
 	if (!tunnel)
 		goto discard_sess;
 
-	/* Trace packet contents, if enabled */
-	if (tunnel->debug & L2TP_MSG_DATA) {
-		length = min(32u, skb->len);
-		if (!pskb_may_pull(skb, length))
-			goto discard_sess;
-
-		/* Point to L2TP header */
-		optr = skb->data;
-		ptr = skb->data;
-		ptr += 4;
-		pr_debug("%s: ip recv\n", tunnel->name);
-		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
-	}
-
 	if (l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr))
 		goto discard_sess;
 

net/l2tp/l2tp_netlink.c

@@ -229,9 +229,6 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info
 			goto out;
 	}
 
-	if (attrs[L2TP_ATTR_DEBUG])
-		cfg.debug = nla_get_u32(attrs[L2TP_ATTR_DEBUG]);
-
 	ret = -EINVAL;
 	switch (cfg.encap) {
 	case L2TP_ENCAPTYPE_UDP:
@@ -307,9 +304,6 @@ static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info
 		goto out;
 	}
 
-	if (info->attrs[L2TP_ATTR_DEBUG])
-		tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
-
 	ret = l2tp_tunnel_notify(&l2tp_nl_family, info,
 				 tunnel, L2TP_CMD_TUNNEL_MODIFY);
 
@@ -400,7 +394,7 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
 	if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
 	    nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
-	    nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
+	    nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
 	    nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
 		goto nla_put_failure;
 
@@ -605,9 +599,6 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf
 			cfg.ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]);
 	}
 
-	if (info->attrs[L2TP_ATTR_DEBUG])
-		cfg.debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
-
 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
 		cfg.recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 
@@ -689,9 +680,6 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf
 		goto out;
 	}
 
-	if (info->attrs[L2TP_ATTR_DEBUG])
-		session->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]);
-
 	if (info->attrs[L2TP_ATTR_RECV_SEQ])
 		session->recv_seq = nla_get_u8(info->attrs[L2TP_ATTR_RECV_SEQ]);
 
@@ -730,7 +718,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
 	    nla_put_u32(skb, L2TP_ATTR_SESSION_ID, session->session_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
 	    nla_put_u32(skb, L2TP_ATTR_PEER_SESSION_ID, session->peer_session_id) ||
-	    nla_put_u32(skb, L2TP_ATTR_DEBUG, session->debug) ||
+	    nla_put_u32(skb, L2TP_ATTR_DEBUG, 0) ||
 	    nla_put_u16(skb, L2TP_ATTR_PW_TYPE, session->pwtype))
 		goto nla_put_failure;
 

net/l2tp/l2tp_ppp.c

@@ -237,17 +237,9 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int
 	if (sk->sk_state & PPPOX_BOUND) {
 		struct pppox_sock *po;
 
-		l2tp_dbg(session, L2TP_MSG_DATA,
-			 "%s: recv %d byte data frame, passing to ppp\n",
-			 session->name, data_len);
-
 		po = pppox_sk(sk);
 		ppp_input(&po->chan, skb);
 	} else {
-		l2tp_dbg(session, L2TP_MSG_DATA,
-			 "%s: recv %d byte data frame, passing to L2TP socket\n",
-			 session->name, data_len);
-
 		if (sock_queue_rcv_skb(sk, skb) < 0) {
 			atomic_long_inc(&session->stats.rx_errors);
 			kfree_skb(skb);
@@ -259,7 +251,7 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int
 
 no_sock:
 	rcu_read_unlock();
-	l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name);
+	pr_warn_ratelimited("%s: no socket in recv\n", session->name);
 	kfree_skb(skb);
 }
 
@@ -710,7 +702,6 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 		if (!tunnel) {
 			struct l2tp_tunnel_cfg tcfg = {
 				.encap = L2TP_ENCAPTYPE_UDP,
-				.debug = 0,
 			};
 
 			/* Prevent l2tp_tunnel_register() from trying to set up
@@ -840,8 +831,6 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 	drop_refcnt = false;
 
 	sk->sk_state = PPPOX_CONNECTED;
-	l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n",
-		  session->name);
 
 end:
 	if (error) {
@@ -1157,9 +1146,7 @@ static int pppol2tp_tunnel_setsockopt(struct sock *sk,
 
 	switch (optname) {
 	case PPPOL2TP_SO_DEBUG:
-		tunnel->debug = val;
-		l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
-			  tunnel->name, tunnel->debug);
+		/* Tunnel debug flags option is deprecated */
 		break;
 
 	default:
@@ -1185,9 +1172,6 @@ static int pppol2tp_session_setsockopt(struct sock *sk,
 			break;
 		}
 		session->recv_seq = !!val;
-		l2tp_info(session, L2TP_MSG_CONTROL,
-			  "%s: set recv_seq=%d\n",
-			  session->name, session->recv_seq);
 		break;
 
 	case PPPOL2TP_SO_SENDSEQ:
@@ -1203,9 +1187,6 @@ static int pppol2tp_session_setsockopt(struct sock *sk,
 				PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
 		}
 		l2tp_session_set_header_len(session, session->tunnel->version);
-		l2tp_info(session, L2TP_MSG_CONTROL,
-			  "%s: set send_seq=%d\n",
-			  session->name, session->send_seq);
 		break;
 
 	case PPPOL2TP_SO_LNSMODE:
@@ -1214,22 +1195,14 @@ static int pppol2tp_session_setsockopt(struct sock *sk,
 			break;
 		}
 		session->lns_mode = !!val;
-		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, L2TP_MSG_CONTROL, "%s: set debug=%x\n",
-			  session->name, session->debug);
+		/* Session debug flags option is deprecated */
 		break;
 
 	case PPPOL2TP_SO_REORDERTO:
 		session->reorder_timeout = msecs_to_jiffies(val);
-		l2tp_info(session, L2TP_MSG_CONTROL,
-			  "%s: set reorder_timeout=%d\n",
-			  session->name, session->reorder_timeout);
 		break;
 
 	default:
@@ -1297,9 +1270,8 @@ static int pppol2tp_tunnel_getsockopt(struct sock *sk,
 
 	switch (optname) {
 	case PPPOL2TP_SO_DEBUG:
-		*val = tunnel->debug;
-		l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n",
-			  tunnel->name, tunnel->debug);
+		/* Tunnel debug flags option is deprecated */
+		*val = 0;
 		break;
 
 	default:
@@ -1321,32 +1293,23 @@ static int pppol2tp_session_getsockopt(struct sock *sk,
 	switch (optname) {
 	case PPPOL2TP_SO_RECVSEQ:
 		*val = session->recv_seq;
-		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, L2TP_MSG_CONTROL,
-			  "%s: get send_seq=%d\n", session->name, *val);
 		break;
 
 	case PPPOL2TP_SO_LNSMODE:
 		*val = session->lns_mode;
-		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, L2TP_MSG_CONTROL, "%s: get debug=%d\n",
-			  session->name, *val);
+		/* Session debug flags option is deprecated */
+		*val = 0;
 		break;
 
 	case PPPOL2TP_SO_REORDERTO:
 		*val = (int)jiffies_to_msecs(session->reorder_timeout);
-		l2tp_info(session, L2TP_MSG_CONTROL,
-			  "%s: get reorder_timeout=%d\n", session->name, *val);
 		break;
 
 	default:
@@ -1534,7 +1497,7 @@ static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)
 		   (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N',
 		   refcount_read(&tunnel->ref_count) - 1);
 	seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n",
-		   tunnel->debug,
+		   0,
 		   atomic_long_read(&tunnel->stats.tx_packets),
 		   atomic_long_read(&tunnel->stats.tx_bytes),
 		   atomic_long_read(&tunnel->stats.tx_errors),
@@ -1580,7 +1543,7 @@ static void pppol2tp_seq_session_show(struct seq_file *m, void *v)
 		   session->recv_seq ? 'R' : '-',
 		   session->send_seq ? 'S' : '-',
 		   session->lns_mode ? "LNS" : "LAC",
-		   session->debug,
+		   0,
 		   jiffies_to_msecs(session->reorder_timeout));
 	seq_printf(m, "   %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n",
 		   session->nr, session->ns,

net/l2tp/trace.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM l2tp
+
+#if !defined(_TRACE_L2TP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_L2TP_H
+
+#include <linux/tracepoint.h>
+#include <linux/l2tp.h>
+#include "l2tp_core.h"
+
+#define encap_type_name(e) { L2TP_ENCAPTYPE_##e, #e }
+#define show_encap_type_name(val) \
+	__print_symbolic(val, \
+			encap_type_name(UDP), \
+			encap_type_name(IP))
+
+#define pw_type_name(p) { L2TP_PWTYPE_##p, #p }
+#define show_pw_type_name(val) \
+	__print_symbolic(val, \
+	pw_type_name(ETH_VLAN), \
+	pw_type_name(ETH), \
+	pw_type_name(PPP), \
+	pw_type_name(PPP_AC), \
+	pw_type_name(IP))
+
+DECLARE_EVENT_CLASS(tunnel_only_evt,
+	TP_PROTO(struct l2tp_tunnel *tunnel),
+	TP_ARGS(tunnel),
+	TP_STRUCT__entry(
+		__array(char, name, L2TP_TUNNEL_NAME_MAX)
+	),
+	TP_fast_assign(
+		memcpy(__entry->name, tunnel->name, L2TP_TUNNEL_NAME_MAX);
+	),
+	TP_printk("%s", __entry->name)
+);
+
+DECLARE_EVENT_CLASS(session_only_evt,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session),
+	TP_STRUCT__entry(
+		__array(char, name, L2TP_SESSION_NAME_MAX)
+	),
+	TP_fast_assign(
+		memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX);
+	),
+	TP_printk("%s", __entry->name)
+);
+
+TRACE_EVENT(register_tunnel,
+	TP_PROTO(struct l2tp_tunnel *tunnel),
+	TP_ARGS(tunnel),
+	TP_STRUCT__entry(
+		__array(char, name, L2TP_TUNNEL_NAME_MAX)
+		__field(int, fd)
+		__field(u32, tid)
+		__field(u32, ptid)
+		__field(int, version)
+		__field(enum l2tp_encap_type, encap)
+	),
+	TP_fast_assign(
+		memcpy(__entry->name, tunnel->name, L2TP_TUNNEL_NAME_MAX);
+		__entry->fd = tunnel->fd;
+		__entry->tid = tunnel->tunnel_id;
+		__entry->ptid = tunnel->peer_tunnel_id;
+		__entry->version = tunnel->version;
+		__entry->encap = tunnel->encap;
+	),
+	TP_printk("%s: type=%s encap=%s version=L2TPv%d tid=%u ptid=%u fd=%d",
+		__entry->name,
+		__entry->fd > 0 ? "managed" : "unmanaged",
+		show_encap_type_name(__entry->encap),
+		__entry->version,
+		__entry->tid,
+		__entry->ptid,
+		__entry->fd)
+);
+
+DEFINE_EVENT(tunnel_only_evt, delete_tunnel,
+	TP_PROTO(struct l2tp_tunnel *tunnel),
+	TP_ARGS(tunnel)
+);
+
+DEFINE_EVENT(tunnel_only_evt, free_tunnel,
+	TP_PROTO(struct l2tp_tunnel *tunnel),
+	TP_ARGS(tunnel)
+);
+
+TRACE_EVENT(register_session,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session),
+	TP_STRUCT__entry(
+		__array(char, name, L2TP_SESSION_NAME_MAX)
+		__field(u32, tid)
+		__field(u32, ptid)
+		__field(u32, sid)
+		__field(u32, psid)
+		__field(enum l2tp_pwtype, pwtype)
+	),
+	TP_fast_assign(
+		memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX);
+		__entry->tid = session->tunnel ? session->tunnel->tunnel_id : 0;
+		__entry->ptid = session->tunnel ? session->tunnel->peer_tunnel_id : 0;
+		__entry->sid = session->session_id;
+		__entry->psid = session->peer_session_id;
+		__entry->pwtype = session->pwtype;
+	),
+	TP_printk("%s: pseudowire=%s sid=%u psid=%u tid=%u ptid=%u",
+		__entry->name,
+		show_pw_type_name(__entry->pwtype),
+		__entry->sid,
+		__entry->psid,
+		__entry->sid,
+		__entry->psid)
+);
+
+DEFINE_EVENT(session_only_evt, delete_session,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session)
+);
+
+DEFINE_EVENT(session_only_evt, free_session,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session)
+);
+
+DEFINE_EVENT(session_only_evt, session_seqnum_lns_enable,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session)
+);
+
+DEFINE_EVENT(session_only_evt, session_seqnum_lns_disable,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session)
+);
+
+DECLARE_EVENT_CLASS(session_seqnum_evt,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session),
+	TP_STRUCT__entry(
+		__array(char, name, L2TP_SESSION_NAME_MAX)
+		__field(u32, ns)
+		__field(u32, nr)
+	),
+	TP_fast_assign(
+		memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX);
+		__entry->ns = session->ns;
+		__entry->nr = session->nr;
+	),
+	TP_printk("%s: ns=%u nr=%u",
+		__entry->name,
+		__entry->ns,
+		__entry->nr)
+);
+
+DEFINE_EVENT(session_seqnum_evt, session_seqnum_update,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session)
+);
+
+DEFINE_EVENT(session_seqnum_evt, session_seqnum_reset,
+	TP_PROTO(struct l2tp_session *session),
+	TP_ARGS(session)
+);
+
+DECLARE_EVENT_CLASS(session_pkt_discard_evt,
+	TP_PROTO(struct l2tp_session *session, u32 pkt_ns),
+	TP_ARGS(session, pkt_ns),
+	TP_STRUCT__entry(
+		__array(char, name, L2TP_SESSION_NAME_MAX)
+		__field(u32, pkt_ns)
+		__field(u32, my_nr)
+		__field(u32, reorder_q_len)
+	),
+	TP_fast_assign(
+		memcpy(__entry->name, session->name, L2TP_SESSION_NAME_MAX);
+		__entry->pkt_ns = pkt_ns,
+		__entry->my_nr = session->nr;
+		__entry->reorder_q_len = skb_queue_len(&session->reorder_q);
+	),
+	TP_printk("%s: pkt_ns=%u my_nr=%u reorder_q_len=%u",
+		__entry->name,
+		__entry->pkt_ns,
+		__entry->my_nr,
+		__entry->reorder_q_len)
+);
+
+DEFINE_EVENT(session_pkt_discard_evt, session_pkt_expired,
+	TP_PROTO(struct l2tp_session *session, u32 pkt_ns),
+	TP_ARGS(session, pkt_ns)
+);
+
+DEFINE_EVENT(session_pkt_discard_evt, session_pkt_outside_rx_window,
+	TP_PROTO(struct l2tp_session *session, u32 pkt_ns),
+	TP_ARGS(session, pkt_ns)
+);
+
+DEFINE_EVENT(session_pkt_discard_evt, session_pkt_oos,
+	TP_PROTO(struct l2tp_session *session, u32 pkt_ns),
+	TP_ARGS(session, pkt_ns)
+);
+
+#endif /* _TRACE_L2TP_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+#include <trace/define_trace.h>