l2tp: add tracepoint definitions in trace.h

l2tp can provide a better debug experience using tracepoints rather than
printk-style logging.

Add tracepoint definitions in trace.h for use in the l2tp subsystem
code.

Add preprocessor definitions for the length of session and tunnel names
in l2tp_core.h so we can reuse these in trace.h.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 200 insertions, 2 deletions

diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index 3468d6b177a0..835c4645a0ec 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -66,6 +66,7 @@ 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;
@@ -90,7 +91,7 @@ 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? */
@@ -154,6 +155,7 @@ 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 */
 
@@ -170,7 +172,7 @@ struct l2tp_tunnel {
 	u32			peer_tunnel_id;
 	int			version;	/* 2=>L2TPv2, 3=>L2TPv3 */
 
-	char			name[20];	/* for logging */
+	char			name[L2TP_TUNNEL_NAME_MAX]; /* for logging */
 	int			debug;		/* bitmask of debug message categories */
 	enum l2tp_encap_type	encap;
 	struct l2tp_stats	stats;
diff --git a/net/l2tp/trace.h b/net/l2tp/trace.h
index 652778291b77..8596eaa12a2e 100644
--- a/net/l2tp/trace.h
+++ b/net/l2tp/trace.h
@@ -5,6 +5,202 @@
 #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 */