From 682e6360f0e544a28610690d823ac53ab5c10d47 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 17 Jan 2001 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2001-01-17

---
 bitsy/sa1110uart.c  |   1 +
 ip/loopbackmedium.c | 119 ++++++++++++++++++++++++++++++++++++++++++++
 ip/tcp.c            |   3 +-
 port/portfns.h      |   1 +
 4 files changed, 123 insertions(+), 1 deletion(-)
 create mode 100644 ip/loopbackmedium.c

diff --git a/bitsy/sa1110uart.c b/bitsy/sa1110uart.c
index 68ecec5443f9769c65cf9ab855ee31da6bd18111..ed636e3f700774203329f4dd14d7c9e3da4a1be5 100644
--- a/bitsy/sa1110uart.c
+++ b/bitsy/sa1110uart.c
@@ -434,6 +434,7 @@ sa1100_uartsetup(int console)
 	gpclkregs = mapspecial(GPCLKREGS, 64);
 	gpclkregs->r0 = Gpclk_sus;	/* set uart mode */
 	uart1regs = mapspecial(UART1REGS, 64);
+
 	p = uartsetup(&sa1100_uart, uart1regs, ClockFreq, "serialport1");
 	uartspecial(p, 115200, 0, 0, µcputc);
 	intrenable(IRQ, IRQuart1b, sa1100_uartintr, p, p->name);
diff --git a/ip/loopbackmedium.c b/ip/loopbackmedium.c
new file mode 100644
index 0000000000000000000000000000000000000000..6bc98b9281999a76a3bfb7965afc6f971d16c333
--- /dev/null
+++ b/ip/loopbackmedium.c
@@ -0,0 +1,119 @@
+#include "u.h"
+#include "../port/lib.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "../port/error.h"
+
+#include "ip.h"
+
+enum
+{
+	Maxtu=	16*1024,
+};
+
+typedef struct LB LB;
+struct LB
+{
+	Proc	*readp;
+	Queue	*q;
+	Fs	*f;
+};
+
+static void loopbackread(void *a);
+
+static void
+loopbackbind(Ipifc *ifc, int, char**)
+{
+	LB *lb;
+
+	lb = smalloc(sizeof(*lb));
+	lb->f = ifc->conv->p->f;
+	lb->q = qopen(128*1024, 1, nil, nil);
+	ifc->arg = lb;
+
+	kproc("loopbackread", loopbackread, ifc);
+
+}
+
+static void
+loopbackunbind(Ipifc *ifc)
+{
+	LB *lb = ifc->arg;
+
+	if(lb->readp)
+		postnote(lb->readp, 1, "unbind", 0);
+
+	/* wait for reader to die */
+	while(lb->readp != 0)
+		tsleep(&up->sleep, return0, 0, 300);
+
+	/* clean up */
+	qfree(lb->q);
+	free(lb);
+}
+
+static void
+loopbackbwrite(Ipifc *ifc, Block *bp, int, uchar*)
+{
+	LB *lb;
+
+	lb = ifc->arg;
+	if(qpass(lb->q, bp) < 0)
+		ifc->outerr++;
+	ifc->out++;
+}
+
+static void
+loopbackread(void *a)
+{
+	Ipifc *ifc;
+	Block *bp;
+	LB *lb;
+
+	ifc = a;
+	lb = ifc->arg;
+	lb->readp = up;	/* hide identity under a rock for unbind */
+	if(waserror()){
+		lb->readp = 0;
+		pexit("hangup", 1);
+	}
+	for(;;){
+		bp = qbread(lb->q, Maxtu);
+		if(bp == nil)
+			continue;
+		ifc->in++;
+		if(!canrlock(ifc)){
+			freeb(bp);
+			continue;
+		}
+		if(waserror()){
+			runlock(ifc);
+			nexterror();
+		}
+		if(ifc->lifc == nil)
+			freeb(bp);
+		else
+			ipiput(lb->f, ifc->lifc->local, bp);
+		runlock(ifc);
+		poperror();
+	}
+}
+
+Medium loopbackmedium =
+{
+.hsize=		0,
+.minmtu=	0,
+.maxmtu=	Maxtu,
+.maclen=	0,
+.name=		"loopback",
+.bind=		loopbackbind,
+.unbind=	loopbackunbind,
+.bwrite=	loopbackbwrite,
+};
+
+void
+loopbackmediumlink(void)
+{
+	addipmedium(&loopbackmedium);
+}
diff --git a/ip/tcp.c b/ip/tcp.c
index 9d514994bcb8422255814ed6d6baad818c342548..bf9cf1c50c8941df700fa16bc93ee575e57256b3 100644
--- a/ip/tcp.c
+++ b/ip/tcp.c
@@ -333,8 +333,9 @@ tcpstate(Conv *c, char *state, int n)
 	s = (Tcpctl*)(c->ptcl);
 
 	return snprint(state, n,
-		"%s srtt %d mdev %d timer.start %d timer.count %d\n",
+		"%s srtt %d mdev %d cwin %d swin %d timer.start %d timer.count %d\n",
 		tcpstates[s->state], s->srtt, s->mdev,
+		s->cwind, s->snd.wnd,
 		s->timer.start, s->timer.count);
 }
 
diff --git a/port/portfns.h b/port/portfns.h
index 318155c5db51ebb1eeff7c4c65731619975ef157..f51001541a19f1241364282331c22238f0ba0706 100644
--- a/port/portfns.h
+++ b/port/portfns.h
@@ -235,6 +235,7 @@ int		qconsume(Queue*, void*, int);
 Block*		qcopy(Queue*, int, ulong);
 void		qdiscard(Queue*, int);
 void		qflush(Queue*);
+void		qfree(Queue*);
 int		qfull(Queue*);
 Block*		qget(Queue*);
 void		qhangup(Queue*, char*);