From 957ee47817249ac0bf155ec1542f81577bb4b97f Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Sun, 23 Feb 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-02-23

---
 port/devdk.c     |  5 ++---
 port/devip.c     |  2 ++
 port/tcpif.c     | 10 ++++++----
 port/tcpoutput.c |  2 ++
 4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/port/devdk.c b/port/devdk.c
index f9d8358e754a06b7523b9adaaf3f6e982cf5a38c..9bb0a5cd8692959b215c3c4e9b63ec3f55887523 100644
--- a/port/devdk.c
+++ b/port/devdk.c
@@ -308,8 +308,7 @@ dkalloc(char *name, int ncsc, int lines)
 }
 
 /*
- *  a new dkmux.  find a free dk structure and assign it to this queue.
- *  when we get though here dp->s is meaningful and the name is set to "/".
+ *  a new dkmux.  hold the stream in place so it can never be closed down.
  */
 static void
 dkmuxopen(Queue *q, Stream *s)
@@ -322,7 +321,7 @@ dkmuxopen(Queue *q, Stream *s)
 }
 
 /*
- *  close down a dkmux
+ *  close down a dkmux, this shouldn't happen
  */
 static void
 dkmuxclose(Queue *q)
diff --git a/port/devip.c b/port/devip.c
index e9a6890f51e5e3764de3c5cbe374efdec9428f9d..b947764b6a140cb021ea7e89c65c7bfcada72c04 100644
--- a/port/devip.c
+++ b/port/devip.c
@@ -663,7 +663,9 @@ tcpstclose(Queue *q)
 	tcb = &s->tcpctl;
 
 	/* Not interested in data anymore */
+	qlock(s);
 	s->readq = 0;
+	qunlock(s);
 
 	switch(tcb->state){
 	case Closed:
diff --git a/port/tcpif.c b/port/tcpif.c
index 494ac5de9e0c9df988e94560bba549f651b3577a..8b22d7971b2601d3f87897bab0b5a72b415ea577 100644
--- a/port/tcpif.c
+++ b/port/tcpif.c
@@ -29,9 +29,6 @@ state_upcall(Ipconv *s, char oldstate, char newstate)
 		s->dst = 0;
 		/* NO break */
 	case Close_wait:		/* Remote closes */
-		if(s->readq == 0)
-			break;
-
 		if(s->err) {
 			len = strlen(s->err);
 			bp = allocb(len);
@@ -43,7 +40,12 @@ state_upcall(Ipconv *s, char oldstate, char newstate)
 
 		bp->flags |= S_DELIM;
 		bp->type = M_HANGUP;
-		PUTNEXT(s->readq, bp);
+		qlock(s);
+		if(s->readq == 0)
+			freeb(bp);
+		else
+			PUTNEXT(s->readq, bp);
+		qunlock(s);
 		break;
 	}
 }
diff --git a/port/tcpoutput.c b/port/tcpoutput.c
index b3369e834e11bd23f472a1677795cd09c4858c83..23d7589351a8c0f454479ea97109e2ab9c8d1277 100644
--- a/port/tcpoutput.c
+++ b/port/tcpoutput.c
@@ -239,6 +239,7 @@ tcprcvwin(Ipconv *s)
 	Tcpctl *tcb = &s->tcpctl;
 
 	/* Calculate new window */
+	qlock(s);
 	if(s->readq) {
 		tcb->rcv.wnd = Streamhi - s->readq->next->len;
 		if(tcb->rcv.wnd < 0)
@@ -246,6 +247,7 @@ tcprcvwin(Ipconv *s)
 	}
 	else
 		tcb->rcv.wnd = Streamhi;
+	qunlock(s);
 }
 
 /*