From 744448b127802672eb7384a101bf523714e9cd0f Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 29 Jan 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-01-29

---
 port/devcons.c  |  2 +-
 port/devnonet.c |  5 ++++-
 port/devscc.c   | 23 ++++++++++++++++++++++-
 port/devwren.c  |  5 ++++-
 port/sysproc.c  |  2 ++
 5 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/port/devcons.c b/port/devcons.c
index 57499479b9d3d28bd473ab34c77b34c1b42d8567..a6a04fe29781810781f25888e67f5bd7df5c63b7 100644
--- a/port/devcons.c
+++ b/port/devcons.c
@@ -821,7 +821,7 @@ conswrite(Chan *c, void *va, long n, ulong offset)
 			error(Eperm);
 		strncpy(u->p->user, a+8, NAMELEN);
 		u->p->user[NAMELEN-1] = '\0';
-		memmove(u->p->pgrp->crypt->key, a+NAMELEN+DESKEYLEN, DESKEYLEN);
+		memmove(u->p->pgrp->crypt->key, a+8+NAMELEN, DESKEYLEN);
 		break;
 
 	case Qnull:
diff --git a/port/devnonet.c b/port/devnonet.c
index 341c9e5338665f073f4c0c1cf610c5448c0b476b..079e72666a73b1a5aa505961ce7ae55f33098fb2 100644
--- a/port/devnonet.c
+++ b/port/devnonet.c
@@ -376,7 +376,10 @@ nonetwrite(Chan *c, void *a, long n, ulong offset)
 	 *  easier to do here than in nooput
 	 */
 	if(t == Sctlqid){
-		strncpy(buf, a, sizeof buf);
+		if(n > sizeof buf - 1)
+			n = sizeof buf - 1;
+		strncpy(buf, a, n);
+		buf[n] = '\0';
 		m = getfields(buf, field, 5, ' ');
 		if(strcmp(field[0], "connect")==0){
 			if(m < 2)
diff --git a/port/devscc.c b/port/devscc.c
index 70909c2d1e29d1201f185074ea4534033ec1b9a6..0abf51315a1c20b5e732d2b12f733d8bf710bad8 100644
--- a/port/devscc.c
+++ b/port/devscc.c
@@ -101,10 +101,16 @@ struct SCC
 	Rendez	r;		/* kproc waiting for input */
 	Alarm	*a;		/* alarm for waking the kernel process */
  	int	kstarted;	/* kproc started */
+
+	/* idiot flow control */
+	int	xonoff;		/* true if we obey this tradition */
+	int	blocked;	/* abstinence */
 };
 
 int	nscc;
 SCC	*scc[8];	/* up to 4 8530's */
+#define CTLS	023
+#define CTLQ	021
 
 void
 onepointseven(void)
@@ -272,7 +278,7 @@ sccputs(IOQ *cq, char *s, int n)
 	x = splhi();
 	lock(cq);
 	puts(cq, s, n);
-	if(sp->printing == 0){
+	if(sp->printing == 0 && sp->blocked==0){
 		ch = getc(cq);
 		/*kprint("<start %2.2ux>", ch);*/
 		if(ch >= 0){
@@ -303,6 +309,12 @@ sccintr0(SCC *sp, uchar x)
 		while(*sp->ptr&RxReady){
 			onepointseven();
 			ch = *sp->data;
+			if (ch == CTLS && sp->xonoff)
+				sp->blocked = 1;
+			else if (ch == CTLQ && sp->xonoff) {
+				sp->blocked = 0;
+				sccputs(sp->oq, "", 0);
+			}
 			if(cq->putc)
 				(*cq->putc)(cq, ch);
 			else
@@ -310,6 +322,11 @@ sccintr0(SCC *sp, uchar x)
 		}
 	}
 	if(x & TxPendB){
+		if (sp->blocked) {
+			sccwrreg(sp, 0, ResTxPend);
+			sp->printing = 0;
+			return;
+		}
 		cq = sp->oq;
 		lock(cq);
 		ch = getc(cq);
@@ -503,6 +520,10 @@ sccoput(Queue *q, Block *bp)
 		case 'w':
 			/* obsolete */
 			break;
+		case 'X':
+		case 'x':
+			sp->xonoff = n;
+			break;
 		}
 	}else while((m = BLEN(bp)) > 0){
 		while ((n = canputc(cq)) == 0){
diff --git a/port/devwren.c b/port/devwren.c
index ed0921e7469bcf739cb12cda8be9dc9b185f326d..2815e14f66e769e97c9ce111766606a114e2ed1f 100644
--- a/port/devwren.c
+++ b/port/devwren.c
@@ -185,7 +185,10 @@ wrenread(Chan *c, char *a, long n, ulong offset)
 long
 wrenwrite(Chan *c, char *a, long n, ulong offset)
 {
-	return wrenio(c, 1, a, n, offset);
+	n = wrenio(c, 1, a, n, offset);
+	if(n)
+		return n;
+	error("end of device");
 }
 
 static long
diff --git a/port/sysproc.c b/port/sysproc.c
index 4f18acea231884b568667eefd36c06221e6b647c..0dae5f278f54af37212a58ead064441f7e74e5e3 100644
--- a/port/sysproc.c
+++ b/port/sysproc.c
@@ -478,6 +478,8 @@ sysforkpgrp(ulong *arg)
 
 	if(mask & FPnamespc)
 		pgrpcpy(pg, u->p->pgrp);
+	else
+		*pg->crypt = *u->p->pgrp->crypt;
 
 	if(mask & FPenv)
 		envcpy(eg, u->p->egrp);