From be01e9e2f2179d5230b0c349cb2234f3b29621ee Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 2 Dec 1993 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1993-12-02

---
 carrera/devether.c | 34 ++++++++++++++++++++++++++++++++++
 port/devlance.c    |  6 ++++++
 port/devproc.c     |  2 +-
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/carrera/devether.c b/carrera/devether.c
index 3102d5272ce18fea6afd25eeb16f17df3455319b..335db963504f24d2cf3deaae8348c3c89884d07e 100644
--- a/carrera/devether.c
+++ b/carrera/devether.c
@@ -682,6 +682,37 @@ isoutbuf(void *arg)
 	return ctlr->tda[ctlr->th].status == Host;
 }
 
+static int
+etherloop(Etherpkt *p, long n)
+{
+	int s, different;
+	ushort t;
+	Netfile *f, **fp;
+
+	different = memcmp(p->d, p->s, sizeof(p->s));
+	if(different && memcmp(p->d, ether.bcast, sizeof(p->d)))
+		return 0;
+
+	s = splhi();
+	t = (p->type[0]<<8) | p->type[1];
+	for(fp = ether.f; fp < &ether.f[Ntypes]; fp++) {
+		f = *fp;
+		if(f == 0)
+			continue;
+		if(f->type == t || f->type < 0)
+			switch(qproduce(f->in, p->d, n)){
+			case -1:
+				print("etherloop overflow\n");
+				break;
+			case -2:
+				print("etherloop memory\n");
+				break;
+			}
+	}
+	splx(s);
+	return !different;
+}
+
 long
 etherwrite(Chan *c, void *buf, long n, ulong offset)
 {
@@ -699,6 +730,9 @@ etherwrite(Chan *c, void *buf, long n, ulong offset)
 		return netifwrite(ether[0], c, buf, n);
 
 	/* we handle data */
+	if(etherloop(buf, n))
+		return n;
+
 	qlock(&ctlr->tlock);
 	if(waserror()) {
 		qunlock(&ctlr->tlock);
diff --git a/port/devlance.c b/port/devlance.c
index da0ff809785eefa24f81ee96f5d4117872859a9f..fbf6d55f2012caa16635cf5121faf50c5e6930f4 100644
--- a/port/devlance.c
+++ b/port/devlance.c
@@ -474,6 +474,11 @@ lancewrite(Chan *c, void *buf, long n, ulong offset)
 		return n;
 
 	qlock(&l.tlock);
+	if(waserror()) {
+		qunlock(&ctlr->tlock);
+		nexterror();
+	}
+
 	m = &(LANCEMEM->tmr[l.tc]);
 	tsleep(&l.tr, isoutbuf, m, 10000);
 	if(!isoutbuf(m) || l.wedged)
@@ -496,6 +501,7 @@ lancewrite(Chan *c, void *buf, long n, ulong offset)
 		*l.rdp = INEA|TDMD;
 	}
 	qunlock(&l.tlock);
+	poperror();
 	return n;
 }
 
diff --git a/port/devproc.c b/port/devproc.c
index 0b6ecf709353ff5a612a733b39d1bf6b9997e78b..6cdb72631462bf2e2b438296091124b8d9761808 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -151,7 +151,7 @@ int
 procwalk(Chan *c, char *name)
 {
 	if(strcmp(name, "..") == 0) {
-		c->qid.path = Qdir|CHDIR;
+		c->qid.path = CHDIR;
 		return 1;
 	}