linux_kernel/include/trace/events/tcp.h

#undef TRACE_SYSTEM
#define TRACE_SYSTEM tcp

#if !defined(_TRACE_TCP_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_TCP_H

#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/tracepoint.h>
#include <net/ipv6.h>

TRACE_EVENT(tcp_retransmit_skb,

	TP_PROTO(struct sock *sk, struct sk_buff *skb),

	TP_ARGS(sk, skb),

	TP_STRUCT__entry(
		__field(void *, skbaddr)
		__field(void *, skaddr)
		__field(__u16, sport)
		__field(__u16, dport)
		__array(__u8, saddr, 4)
		__array(__u8, daddr, 4)
		__array(__u8, saddr_v6, 16)
		__array(__u8, daddr_v6, 16)
	),

	TP_fast_assign(
		struct inet_sock *inet = inet_sk(sk);
		struct in6_addr *pin6;
		__be32 *p32;

		__entry->skbaddr = skb;
		__entry->skaddr = sk;

		__entry->sport = ntohs(inet->inet_sport);
		__entry->dport = ntohs(inet->inet_dport);

		p32 = (__be32 *) __entry->saddr;
		*p32 = inet->inet_saddr;

		p32 = (__be32 *) __entry->daddr;
		*p32 =  inet->inet_daddr;

#if IS_ENABLED(CONFIG_IPV6)
		if (sk->sk_family == AF_INET6) {
			pin6 = (struct in6_addr *)__entry->saddr_v6;
			*pin6 = sk->sk_v6_rcv_saddr;
			pin6 = (struct in6_addr *)__entry->daddr_v6;
			*pin6 = sk->sk_v6_daddr;
		} else
#endif
		{
			pin6 = (struct in6_addr *)__entry->saddr_v6;
			ipv6_addr_set_v4mapped(inet->inet_saddr, pin6);
			pin6 = (struct in6_addr *)__entry->daddr_v6;
			ipv6_addr_set_v4mapped(inet->inet_daddr, pin6);
		}
	),

	TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c",
		  __entry->sport, __entry->dport, __entry->saddr, __entry->daddr,
		  __entry->saddr_v6, __entry->daddr_v6)
);

#endif /* _TRACE_TCP_H */

/* This part must be outside protection */
#include <trace/define_trace.h>