Add new, per connection, statistics for TCP, including:

Retransmitted Packets
Zero Window Advertisements
Out of Order Receives

These statistics are available via the -T argument to
netstat(1).
MFC after:	2 weeks

5 files changed, 15 insertions, 3 deletions

diff --git a/sys/netinet/tcp.h b/sys/netinet/tcp.h
index 62a89f7..443425f 100644
--- a/sys/netinet/tcp.h
+++ b/sys/netinet/tcp.h
@@ -225,9 +225,12 @@ struct tcp_info {
 	u_int32_t	tcpi_snd_nxt;		/* Next egress seqno */
 	u_int32_t	tcpi_rcv_nxt;		/* Next ingress seqno */
 	u_int32_t	tcpi_toe_tid;		/* HWTID for TOE endpoints */
+	u_int32_t	tcpi_snd_rexmitpack;	/* Retransmitted packets */
+	u_int32_t	tcpi_rcv_ooopack;	/* Out-of-order packets */
+	u_int32_t	tcpi_snd_zerowin;	/* Zero-sized windows sent */
 	
 	/* Padding to grow without breaking ABI. */
-	u_int32_t	__tcpi_pad[29];		/* Padding. */
+	u_int32_t	__tcpi_pad[26];		/* Padding. */
 };
 #endif
 
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 7db0adb..bf42dac 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -803,6 +803,7 @@ send:
 		if ((tp->t_flags & TF_FORCEDATA) && len == 1)
 			TCPSTAT_INC(tcps_sndprobe);
 		else if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
+			tp->t_sndrexmitpack++;
 			TCPSTAT_INC(tcps_sndrexmitpack);
 			TCPSTAT_ADD(tcps_sndrexmitbyte, len);
 		} else {
@@ -1027,9 +1028,10 @@ send:
 	 * to read more data than can be buffered prior to transmitting on
 	 * the connection.
 	 */
-	if (th->th_win == 0)
+	if (th->th_win == 0) {
+		tp->t_sndzerowin++;
 		tp->t_flags |= TF_RXWIN0SENT;
-	else
+	} else
 		tp->t_flags &= ~TF_RXWIN0SENT;
 	if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
 		th->th_urp = htons((u_short)(tp->snd_up - tp->snd_nxt));
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index 1d840cd..d430991 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -266,6 +266,7 @@ tcp_reass(struct tcpcb *tp, struct tcphdr *th, int *tlenp, struct mbuf *m)
 			th->th_seq += i;
 		}
 	}
+ 	tp->t_rcvoopack++;
 	TCPSTAT_INC(tcps_rcvoopack);
 	TCPSTAT_ADD(tcps_rcvoobyte, *tlenp);
 
diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c
index a28ddef..a2231ba 100644
--- a/sys/netinet/tcp_usrreq.c
+++ b/sys/netinet/tcp_usrreq.c
@@ -1218,6 +1218,9 @@ tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
 	ti->tcpi_rcv_mss = tp->t_maxseg;
 	if (tp->t_flags & TF_TOE)
 		ti->tcpi_options |= TCPI_OPT_TOE;
+	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
+	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
+	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
 }
 
 /*
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index 7b38667..a37d306 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -177,6 +177,7 @@ struct tcpcb {
 	u_long	snd_cwnd_prev;		/* cwnd prior to retransmit */
 	u_long	snd_ssthresh_prev;	/* ssthresh prior to retransmit */
 	tcp_seq	snd_recover_prev;	/* snd_recover prior to retransmit */
+	int	t_sndzerowin;		/* zero-window updates sent */
 	u_int	t_badrxtwin;		/* window for retransmit recovery */
 	u_char	snd_limited;		/* segments limited transmitted */
 /* SACK related state */
@@ -193,6 +194,8 @@ struct tcpcb {
 	u_int32_t	rfbuf_ts;	/* recv buffer autoscaling timestamp */
 	int	rfbuf_cnt;		/* recv buffer autoscaling byte count */
 	struct toe_usrreqs *t_tu;	/* offload operations vector */
+	int	t_sndrexmitpack;	/* retransmit packets sent */
+	int	t_rcvoopack;		/* out-of-order packets received */
 	void	*t_toe;			/* TOE pcb pointer */
 	int	t_bytes_acked;		/* # bytes acked during current RTT */
 	struct cc_algo	*cc_algo;	/* congestion control algorithm */