From: Stephen Hemminger <redacted>
Date: Thu, 27 Aug 2009 22:49:02 -0700

On Thu, 27 Aug 2009 20:52:32 -0700
Ben Greear [off-list ref] wrote:

quoted

+		default: /* Drivers are not supposed to return other
values! */
+			if (net_ratelimit())
+				pr_info("pktgen: %s xmit error:
%d\n",
+					odev->name, ret);
 			pkt_dev->errors++;

I believe this is faulty.  Things like vlans can send pkts to qdiscs
of the underlying device and those can return other values.

Patric McHardy put in some patches recently to achieve this in a more
uniform manner:

http://patchwork.ozlabs.org/patch/28340/

Thanks,
Ben

Since pktgen has its own way of generating vlan tags, it
makes no sense to use it on top of 8021q vlan driver.

I think Patrick's goals are quite sound, and with his patch we
could let pktgen transmit over vlan just like any other device.

Otherwise we give no way to use pktgen to test the VLAN transmit path.