From c54115d548403a18776fc113c093f02b9b1b7cd6 Mon Sep 17 00:00:00 2001
From: ps <ps@FreeBSD.org>
Date: Thu, 17 Feb 2005 23:04:56 +0000
Subject: [PATCH] Remove 2 (SACK) fields from the tcpcb. These are only used by
 a function that is called from tcp_input(), so they oughta be passed on the
 stack instead of stuck in the tcpcb.

Submitted by:	Mohan Srinivasan
---
 sys/netinet/tcp_input.c |  7 ++-----
 sys/netinet/tcp_reass.c |  7 ++-----
 sys/netinet/tcp_sack.c  | 15 ++++++++-------
 sys/netinet/tcp_var.h   |  4 +---
 4 files changed, 13 insertions(+), 20 deletions(-)

diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c
index c10a94c4b8b1..6255042a55b6 100644
--- a/sys/netinet/tcp_input.c
+++ b/sys/netinet/tcp_input.c
@@ -2295,11 +2295,8 @@ dodata:							/* XXX */
 			thflags = tcp_reass(tp, th, &tlen, m);
 			tp->t_flags |= TF_ACKNOW;
 		}
-		if (tp->sack_enable) {
-			tp->rcv_laststart = th->th_seq; /* last recv'd segment*/
-			tp->rcv_lastend = th->th_seq + tlen;
-			tcp_update_sack_list(tp);
-		}
+		if (tp->sack_enable)
+			tcp_update_sack_list(tp, th->th_seq, th->th_seq + tlen);
 		/*
 		 * Note the amount of data that peer has sent into
 		 * our window, in order to estimate the sender's
diff --git a/sys/netinet/tcp_reass.c b/sys/netinet/tcp_reass.c
index c10a94c4b8b1..6255042a55b6 100644
--- a/sys/netinet/tcp_reass.c
+++ b/sys/netinet/tcp_reass.c
@@ -2295,11 +2295,8 @@ dodata:							/* XXX */
 			thflags = tcp_reass(tp, th, &tlen, m);
 			tp->t_flags |= TF_ACKNOW;
 		}
-		if (tp->sack_enable) {
-			tp->rcv_laststart = th->th_seq; /* last recv'd segment*/
-			tp->rcv_lastend = th->th_seq + tlen;
-			tcp_update_sack_list(tp);
-		}
+		if (tp->sack_enable)
+			tcp_update_sack_list(tp, th->th_seq, th->th_seq + tlen);
 		/*
 		 * Note the amount of data that peer has sent into
 		 * our window, in order to estimate the sender's
diff --git a/sys/netinet/tcp_sack.c b/sys/netinet/tcp_sack.c
index 8637fa29e53b..afedbdf3bf38 100644
--- a/sys/netinet/tcp_sack.c
+++ b/sys/netinet/tcp_sack.c
@@ -175,8 +175,9 @@ TUNABLE_INT("net.inet.tcp.sack.enable", &tcp_do_sack);
  * prediction mode), and it updates the ordered list of sacks.
  */
 void
-tcp_update_sack_list(tp)
+tcp_update_sack_list(tp, rcv_laststart, rcv_lastend)
 	struct tcpcb *tp;
+	tcp_seq rcv_laststart, rcv_lastend;
 {
 	/*
 	 * First reported block MUST be the most recent one.  Subsequent
@@ -206,10 +207,10 @@ tcp_update_sack_list(tp)
 	tp->rcv_numsacks -= count;
 	if (tp->rcv_numsacks == 0) { /* no sack blocks currently (fast path) */
 		tcp_clean_sackreport(tp);
-		if (SEQ_LT(tp->rcv_nxt, tp->rcv_laststart)) {
+		if (SEQ_LT(tp->rcv_nxt, rcv_laststart)) {
 			/* ==> need first sack block */
-			tp->sackblks[0].start = tp->rcv_laststart;
-			tp->sackblks[0].end = tp->rcv_lastend;
+			tp->sackblks[0].start = rcv_laststart;
+			tp->sackblks[0].end = rcv_lastend;
 			tp->rcv_numsacks = 1;
 		}
 		return;
@@ -217,14 +218,14 @@ tcp_update_sack_list(tp)
 	/* Otherwise, sack blocks are already present. */
 	for (i = 0; i < tp->rcv_numsacks; i++)
 		tp->sackblks[i] = temp[i]; /* first copy back sack list */
-	if (SEQ_GEQ(tp->rcv_nxt, tp->rcv_lastend))
+	if (SEQ_GEQ(tp->rcv_nxt, rcv_lastend))
 		return;     /* sack list remains unchanged */
 	/*
 	 * From here, segment just received should be (part of) the 1st sack.
 	 * Go through list, possibly coalescing sack block entries.
 	 */
-	firstsack.start = tp->rcv_laststart;
-	firstsack.end = tp->rcv_lastend;
+	firstsack.start = rcv_laststart;
+	firstsack.end = rcv_lastend;
 	for (i = 0; i < tp->rcv_numsacks; i++) {
 		sack = tp->sackblks[i];
 		if (SEQ_LT(sack.end, firstsack.start) ||
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
index f6473467c812..9047809bc4f0 100644
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -187,8 +187,6 @@ struct tcpcb {
 	int	sack_enable;		/* enable SACK for this connection */
 	int	snd_numholes;		/* number of holes seen by sender */
 	struct sackhole *snd_holes;	/* linked list of holes (sorted) */
-	tcp_seq	rcv_laststart;		/* start of last segment recd. */
-	tcp_seq	rcv_lastend;		/* end of ... */
 	tcp_seq	rcv_lastsack;		/* last seq number(+1) sack'd by rcv'r*/
 	int	rcv_numsacks;		/* # distinct sack blks present */
 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
@@ -575,7 +573,7 @@ extern	u_long tcp_recvspace;
 tcp_seq tcp_new_isn(struct tcpcb *);
 
 int	 tcp_sack_option(struct tcpcb *,struct tcphdr *,u_char *,int);
-void	 tcp_update_sack_list(struct tcpcb *tp);
+void	 tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_laststart, tcp_seq rcv_lastend);
 void	 tcp_del_sackholes(struct tcpcb *, struct tcphdr *);
 void	 tcp_clean_sackreport(struct tcpcb *tp);
 void	 tcp_sack_adjust(struct tcpcb *tp);