Use etherusb kernel proxy (when available - so far only on Raspberry Pi) to pack/unpack and
send/receive packets between usb pipes and kernel ether queues.

Reference: /n/sources/patch/applied/usb-ether-kernelproxy-1
Date: Mon Nov 12 22:12:49 CET 2012
Signed-off-by: miller@hamnavoe.com

--- /sys/src/cmd/usb/ether/ether.h	Mon Nov 12 22:09:56 2012
+++ /sys/src/cmd/usb/ether/ether.h	Mon Nov 12 22:09:54 2012
@@ -58,6 +58,8 @@
 	int	(*multicast)(Ether*, uchar*, int);
 	char*	(*seprintstats)(char*, char*, Ether*);
 	void	(*free)(Ether*);
+	int	bufsize;
+	char	*name;
 	void*	aux;
 };
 
--- /sys/src/cmd/usb/ether/asix.c	Mon Nov 12 22:10:00 2012
+++ /sys/src/cmd/usb/ether/asix.c	Mon Nov 12 22:09:58 2012
@@ -474,7 +474,9 @@
 				return -1;
 			}
 			deprint(2, "%s: asix reset done\n", argv0);
+			ether->name = "asix";
 			ether->aux = emallocz(sizeof(Buf), 1);
+			ether->bufsize = Hdrsize+Maxpkt;
 			ether->bread = asixbread;
 			ether->bwrite = asixbwrite;
 			ether->free = asixfree;
--- /sys/src/cmd/usb/ether/ether.c	Mon Nov 12 22:10:06 2012
+++ /sys/src/cmd/usb/ether/ether.c	Mon Nov 12 22:10:03 2012
@@ -174,7 +174,7 @@
 		qunlock(e);
 	}
 	if(bp == nil){
-		fprint(2, "%s: blocked waiting for allocbuf\n", argv0);
+		deprint(2, "%s: blocked waiting for allocbuf\n", argv0);
 		bp = recvp(e->bc);
 	}
 	bp->rp = bp->data + Hdrsize;
@@ -802,7 +802,7 @@
 		if(e->nblock == 0)
 			sendp(e->wc, bp);
 		else if(nbsendp(e->wc, bp) == 0){
-			fprint(2, "%s: (out) packet lost\n", argv0);
+			deprint(2, "%s: (out) packet lost\n", argv0);
 			e->noerrs++;
 			freebuf(e, bp);
 		}
@@ -1038,7 +1038,7 @@
 					dbp->type = bp->type;
 				}
 				if(nbsendp(e->conns[i]->rc, dbp) == 0){
-					fprint(2, "%s: (in) packet lost\n", argv0);
+					deprint(2, "%s: (in) packet lost\n", argv0);
 					e->nierrs++;
 					freebuf(e, dbp);
 				}
@@ -1142,6 +1142,34 @@
 	return -1;
 }
 
+static int
+kernelproxy(Ether *e)
+{
+	int ctlfd, n;
+	char eaddr[13];
+
+	ctlfd = open("#l0/ether0/clone", ORDWR);
+	if(ctlfd < 0){
+		deprint(2, "%s: etherusb bind #l0: %r\n", argv0);
+		return -1;
+	}
+	close(e->epin->dfd);
+	close(e->epout->dfd);
+	seprintaddr(eaddr, eaddr+sizeof(eaddr), e->addr);
+	n = fprint(ctlfd, "bind %s #u/usb/ep%d.%d/data #u/usb/ep%d.%d/data %s %d %d",
+		e->name, e->dev->id, e->epin->id, e->dev->id, e->epout->id,
+		eaddr, e->bufsize, e->epout->maxpkt);
+	if(n < 0){
+		deprint(2, "%s: etherusb bind #l0: %r\n", argv0);
+		opendevdata(e->epin, OREAD);
+		opendevdata(e->epout, OWRITE);
+		close(ctlfd);
+		return -1;
+	}
+	close(ctlfd);
+	return 0;
+}
+
 int
 ethermain(Dev *dev, int argc, char **argv)
 {
@@ -1174,6 +1202,7 @@
 	e->dev = dev;
 	dev->free = etherdevfree;
 	memmove(e->addr, ea, Eaddrlen);
+	e->name = "cdc";
 
 	for(i = 0; i < nelem(ethers); i++)
 		if(ethers[i](e) == 0)
@@ -1188,9 +1217,13 @@
 		e->bwrite = etherbwrite;
 	if(e->bread == nil)
 		e->bread = etherbread;
+	if(e->bufsize == 0)
+		e->bufsize = Maxpkt;
 
 	if(openeps(e, epin, epout) < 0)
 		return -1;
+	if(kernelproxy(e) == 0)
+		return 0;
 	e->fs = etherfs;
 	snprint(e->fs.name, sizeof(e->fs.name), "etherU%d", devid);
 	e->fs.dev = dev;
--- /sys/src/cmd/usb/ether/smsc.c	Mon Nov 12 22:10:10 2012
+++ /sys/src/cmd/usb/ether/smsc.c	Mon Nov 12 22:10:07 2012
@@ -15,7 +15,7 @@
 	Resettime	= 1000,
 	E2pbusytime	= 1000,
 	Afcdefault	= 0xF830A1,
-//	Hsburst		= 37,
+//	Hsburst		= 37,	/* from original linux driver */
 	Hsburst		= 8,
 	Fsburst		= 129,
 	Defbulkdly	= 0x2000,
@@ -214,7 +214,7 @@
 	if(eepromr(d, MACoffset, ea, Eaddrlen) < 0)
 		return -1;
 	for(i = 0; i < Eaddrlen; i++)
-		if(ea[i] != 0){
+		if(ea[i] != 0 && ea[i] != 0xFF){
 			memmove(buf, ea, Eaddrlen);
 			break;
 		}
@@ -275,7 +275,7 @@
 	if(rbp->ndata < 4){
 		rbp->rp = rbp->data;
 		rbp->ndata = read(e->epin->dfd, rbp->rp, Doburst? Hsburst*512:
-			sizeof(rbp->data));
+			Maxpkt);
 		if(rbp->ndata < 0)
 			return -1;
 	}
@@ -342,7 +342,14 @@
 				return -1;
 			}
 			deprint(2, "%s: smsc reset done\n", argv0);
-			ether->aux = emallocz(sizeof(Buf) + Hsburst*512 - Maxpkt, 1);
+			ether->name = "smsc";
+			if(Doburst){
+				ether->bufsize = Hsburst*512;
+				ether->aux = emallocz(sizeof(Buf) + Hsburst*512 - Maxpkt, 1);
+			}else{
+				ether->bufsize = Maxpkt;
+				ether->aux = emallocz(sizeof(Buf), 1);
+			}
 			ether->free = smscfree;
 			ether->bread = smscbread;
 			ether->bwrite = smscbwrite;