[PATCH] Ethernet cleanup; 802.1p input and M_PROMISC

[Yar Tikhiy]

On Fri, Mar 02, 2007 at 11:55:16PM +0000, Bruce M Simpson wrote:
> Hello all,
> 
> I would like to announce an updated version of the 802.1p input patch, 
> available at:
>    http://people.freebsd.org/~bms/dump/latest-8021p.diff
> 
> I have cut down the original scope of the patch. I previously ran into 
> problems when I tried to move VLAN tag input and output processing into 
> if_ethersubr.c.
> 
> FreeBSD should now accept VLAN 0 traffic on input with this patch. In 
> addition to this, the M_PROMISC flag is now used, which considerably 
> simplifies the Ethernet input path in general.
[...]

Sorry, I don't have an opportunity to test your patch, but it looks
good to me.  It seems to remove some cruft from the code, which is
a good sign!  I've got only one question about this piece:

@@ -504,6 +507,10 @@
 	struct ether_header *eh;
 	u_short etype;
 
+	if ((ifp->if_flags & IFF_UP) == 0) {
+		m_freem(m);
+		return;
+	}

In fact, there two independent flags indicating interface's readiness:
IFF_UP and IFF_DRV_RUNNING.  The former is controlled by the admin
and the latter, by the driver.  E.g., an interface can be UP but
not really ready to operate due to h/w reasons, or vice versa.
Perhaps we should check both flags to see if the interface is, so
to say, up and running.  if_vlan.c has an obvious macro for that,
and it can go to if_var.h to avoid code duplication if we decide it's
the right way to take.

-- 
Yar