Subject: Re: 802.1Q & ETHER_MAX_LEN
To: None <thorpej@zembu.com>
From: None <itojun@iijlab.net>
List: tech-net
Date: 10/04/2000 06:58:43
>On Tue, Oct 03, 2000 at 09:09:22AM -0700, Jason R Thorpe wrote:
> > Anyway, I'm cooking up a patch for this... stay tuned.
>Attached is a preliminary patch, along with support for the
>ETHERCAP_VLAN_MTU capability in the `tlp' driver.  Also note
>that there is some preliminary work in the direction of supporting
>802.1Q VLANs on FDDI, as well.

	I think bpf will choke with non-14byte encapsulation on
	DLT_EN10MB.  I think we should inject:
	- 18byte header (as is) on parent interface
	- 14byte header on vlan interface (need to create one)
	into bpf.

itojun


>+ 		/*
>+ 		 * We inherit the parent's Ethernet address.
>+ 		 */
>+ 		ether_ifattach(ifp, LLADDR(p->if_sadl));
>+ 		ifp->if_hdrlen = sizeof(struct ether_vlan_header); /* XXX? */
>+ #if NBPFILTER > 0
>+ 		bpfattach(&ifp->if_bpf, ifp, DLT_EN10MB,
>+ 		    sizeof(struct ether_header));
>+ #endif
>+ 		break;
>+ 	    }