From ded53b4033d64348edff9f7b9fe6d19d8d418ad2 Mon Sep 17 00:00:00 2001
From: silby <silby@FreeBSD.org>
Date: Wed, 16 Sep 2009 05:33:15 +0000
Subject: Add the ability to see TCP timers via netstat -x.  This can be a
 useful feature when you have a seemingly stuck socket and want to figure out
 why it has not been closed yet.

No plans to MFC this, as it changes the netstat sysctl ABI.

Reviewed by:	andre, rwatson, Eric Van Gyzen
---
 sys/netinet/tcp_subr.c  |  5 ++++-
 sys/netinet/tcp_timer.c | 21 +++++++++++++++++++++
 sys/netinet/tcp_timer.h |  4 ++++
 sys/netinet/tcp_var.h   |  9 +++++++++
 4 files changed, 38 insertions(+), 1 deletion(-)

(limited to 'sys/netinet')

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 22b2ace..d0b2e0e 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1151,8 +1151,11 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS)
 			else if (inp->inp_flags & INP_TIMEWAIT) {
 				bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
 				xt.xt_tp.t_state = TCPS_TIME_WAIT;
-			} else
+			} else {
 				bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
+				if (xt.xt_tp.t_timers)
+					tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
+			}
 			if (inp->inp_socket != NULL)
 				sotoxsocket(inp->inp_socket, &xt.xt_socket);
 			else {
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c
index 7f5d159..8ead3dc 100644
--- a/sys/netinet/tcp_timer.c
+++ b/sys/netinet/tcp_timer.c
@@ -659,3 +659,24 @@ tcp_timer_active(struct tcpcb *tp, int timer_type)
 		}
 	return callout_active(t_callout);
 }
+
+#define	ticks_to_msecs(t)	(1000*(t) / hz)
+
+void
+tcp_timer_to_xtimer(struct tcpcb *tp, struct tcp_timer *timer, struct xtcp_timer *xtimer)
+{
+	bzero(xtimer, sizeof(struct xtcp_timer));
+	if (timer == NULL)
+		return;
+	if (callout_active(&timer->tt_delack))
+		xtimer->tt_delack = ticks_to_msecs(timer->tt_delack.c_time - ticks);
+	if (callout_active(&timer->tt_rexmt))
+		xtimer->tt_rexmt = ticks_to_msecs(timer->tt_rexmt.c_time - ticks);
+	if (callout_active(&timer->tt_persist))
+		xtimer->tt_persist = ticks_to_msecs(timer->tt_persist.c_time - ticks);
+	if (callout_active(&timer->tt_keep))
+		xtimer->tt_keep = ticks_to_msecs(timer->tt_keep.c_time - ticks);
+	if (callout_active(&timer->tt_2msl))
+		xtimer->tt_2msl = ticks_to_msecs(timer->tt_2msl.c_time - ticks);
+	xtimer->t_rcvtime = ticks_to_msecs(ticks - tp->t_rcvtime);
+}
diff --git a/sys/netinet/tcp_timer.h b/sys/netinet/tcp_timer.h
index ff455b6..1ab0b7b 100644
--- a/sys/netinet/tcp_timer.h
+++ b/sys/netinet/tcp_timer.h
@@ -141,6 +141,8 @@ static const char *tcptimers[] =
 
 #ifdef _KERNEL
 
+struct xtcp_timer;
+
 struct tcp_timer {
 	struct	callout tt_rexmt;	/* retransmit timer */
 	struct	callout tt_persist;	/* retransmit persistence */
@@ -177,6 +179,8 @@ void	tcp_timer_keep(void *xtp);
 void	tcp_timer_persist(void *xtp);
 void	tcp_timer_rexmt(void *xtp);
 void	tcp_timer_delack(void *xtp);
+void	tcp_timer_to_xtimer(struct tcpcb *tp, struct tcp_timer *timer,
+	struct xtcp_timer *xtimer);
 
 #endif /* _KERNEL */
 
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 96353f3..93d3feb 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -495,11 +495,20 @@ void	kmod_tcpstat_inc(int statnum);
  * included.  Not all of our clients do.
  */
 #if defined(_NETINET_IN_PCB_H_) && defined(_SYS_SOCKETVAR_H_)
+struct xtcp_timer {
+	int tt_rexmt;	/* retransmit timer */
+	int tt_persist;	/* retransmit persistence */
+	int tt_keep;	/* keepalive */
+	int tt_2msl;	/* 2*msl TIME_WAIT timer */
+	int tt_delack;	/* delayed ACK timer */
+	int t_rcvtime; 	/* Time since last packet received */
+};
 struct	xtcpcb {
 	size_t	xt_len;
 	struct	inpcb	xt_inp;
 	struct	tcpcb	xt_tp;
 	struct	xsocket	xt_socket;
+	struct	xtcp_timer xt_timer;
 	u_quad_t	xt_alignment_hack;
 };
 #endif
-- 
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