Re: CVS commit: src/sys/net/if_vlan.c

[Christoph Badura <bad%bsd.de@localhost>]

On Sun, Mar 29, 2015 at 01:30:43PM +0000, Ryota Ozaki wrote:
> Module Name:	src
> Committed By:	ozaki-r
> Date:		Sun Mar 29 13:30:43 UTC 2015
> 
> Modified Files:
> 	src/sys/net: if_vlan.c
> 
> Log Message:
> Correct frame padding length
> 
> vlan pads a frame with zeros up to 68 bytes
> (ETHER_MIN_LEN + ETHER_VLAN_ENCAP_LEN). It expects
> that even if the frame is untagged, it keeps 64 bytes
> at least. However, it lacks concern about CRC
> (4 bytes). So a sending frame can be 72 (68 + 4) bytes.

I don't get it. ETHER_MIN_LEN includes the 4 bytes for the CRC of a
minimum sized packet.  Therefore ETHER_MIN_LEN + ETHER_VLAN_ENCAP_LEN is
the right size, isn't it?

BTW, what do you mean by "it lacks concern about CRC"?

--chris