[RFC PATCH -tip 5/6] net: dccp: Add DCCP sendmsg trace event

[Masami Hiramatsu <mhiramat@kernel.org>]

Add DCCP sendmsg trace event (dccp/dccp_probe) for
replacing dccpprobe. User can trace this event via
ftrace or perftools.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 net/dccp/proto.c |    5 +++
 net/dccp/trace.h |  105 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
 create mode 100644 net/dccp/trace.h

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index b68168fcc06a..77a8a737c4f3 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -38,6 +38,9 @@
 #include "dccp.h"
 #include "feat.h"
 
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
 
 EXPORT_SYMBOL_GPL(dccp_statistics);
@@ -756,6 +759,8 @@ int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	int rc, size;
 	long timeo;
 
+	trace_dccp_probe(sk, len);
+
 	if (len > dp->dccps_mss_cache)
 		return -EMSGSIZE;
 
diff --git a/net/dccp/trace.h b/net/dccp/trace.h
new file mode 100644
index 000000000000..aa01321a6c37
--- /dev/null
+++ b/net/dccp/trace.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM dccp
+
+#if !defined(_TRACE_DCCP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DCCP_H
+
+#include <net/sock.h>
+#include "dccp.h"
+#include "ccids/ccid3.h"
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(dccp_probe,
+
+	TP_PROTO(struct sock *sk, size_t size),
+
+	TP_ARGS(sk, size),
+
+	TP_STRUCT__entry(
+		/* sockaddr_in6 is always bigger than sockaddr_in */
+		__array(__u8, saddr, sizeof(struct sockaddr_in6))
+		__array(__u8, daddr, sizeof(struct sockaddr_in6))
+		__field(__u16, sport)
+		__field(__u16, dport)
+		__field(__u16, size)
+		__field(__u16, tx_s)
+		__field(__u32, tx_rtt)
+		__field(__u32, tx_p)
+		__field(__u32, tx_x_calc)
+		__field(__u64, tx_x_recv)
+		__field(__u64, tx_x)
+		__field(__u32, tx_t_ipi)
+	),
+
+	TP_fast_assign(
+		const struct inet_sock *inet = inet_sk(sk);
+		struct ccid3_hc_tx_sock *hc = NULL;
+
+		if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3)
+			hc = ccid3_hc_tx_sk(sk);
+
+		memset(__entry->saddr, 0, sizeof(struct sockaddr_in6));
+		memset(__entry->daddr, 0, sizeof(struct sockaddr_in6));
+
+		if (sk->sk_family == AF_INET) {
+			struct sockaddr_in *v4 = (void *)__entry->saddr;
+
+			v4->sin_family = AF_INET;
+			v4->sin_port = inet->inet_sport;
+			v4->sin_addr.s_addr = inet->inet_saddr;
+			v4 = (void *)__entry->daddr;
+			v4->sin_family = AF_INET;
+			v4->sin_port = inet->inet_dport;
+			v4->sin_addr.s_addr = inet->inet_daddr;
+#if IS_ENABLED(CONFIG_IPV6)
+		} else if (sk->sk_family == AF_INET6) {
+			struct sockaddr_in6 *v6 = (void *)__entry->saddr;
+
+			v6->sin6_family = AF_INET6;
+			v6->sin6_port = inet->inet_sport;
+			v6->sin6_addr = inet6_sk(sk)->saddr;
+			v6 = (void *)__entry->daddr;
+			v6->sin6_family = AF_INET6;
+			v6->sin6_port = inet->inet_dport;
+			v6->sin6_addr = sk->sk_v6_daddr;
+#endif
+		}
+
+		/* For filtering use */
+		__entry->sport = ntohs(inet->inet_sport);
+		__entry->dport = ntohs(inet->inet_dport);
+
+		__entry->size = size;
+		if (hc) {
+			__entry->tx_s = hc->tx_s;
+			__entry->tx_rtt = hc->tx_rtt;
+			__entry->tx_p = hc->tx_p;
+			__entry->tx_x_calc = hc->tx_x_calc;
+			__entry->tx_x_recv = hc->tx_x_recv >> 6;
+			__entry->tx_x = hc->tx_x >> 6;
+			__entry->tx_t_ipi = hc->tx_t_ipi;
+		} else {
+			__entry->tx_s = 0;
+			memset(&__entry->tx_rtt, 0, (void *)&__entry->tx_t_ipi -
+			       (void *)&__entry->tx_rtt +
+			       sizeof(__entry->tx_t_ipi));
+		}
+	),
+
+	TP_printk("src=%pISpc dest=%pISpc size=%d tx_s=%d tx_rtt=%d "
+		  "tx_p=%d tx_x_calc=%u tx_x_recv=%llu tx_x=%llu tx_t_ipi=%d",
+		  __entry->saddr, __entry->daddr, __entry->size,
+		  __entry->tx_s, __entry->tx_rtt, __entry->tx_p,
+		  __entry->tx_x_calc, __entry->tx_x_recv, __entry->tx_x,
+		  __entry->tx_t_ipi)
+);
+
+#endif /* _TRACE_TCP_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>