In article <rmify1i2zcn.fsf@fnord.ir.bbn.com>,
Greg Troxel  <gdt@ir.bbn.com> wrote:
>I looked at the ifconf() code and now think that the kernel wasn't
>copying the whole sockaddr.  I have compile tested but not run the
>following patch, which I think will fix the 'missing two bytes' of the
>mac address problem, as well as unbreak v6 addresses.
>
>Index: sys/net/if.c
>===================================================================
>RCS file: /cvsroot/src/sys/net/if.c,v
>retrieving revision 1.200
>diff -u -p -r1.200 if.c
>--- sys/net/if.c	11 Sep 2007 19:31:22 -0000	1.200
>+++ sys/net/if.c	13 Sep 2007 18:28:48 -0000
>@@ -1669,7 +1669,7 @@ ifconf(u_long cmd, void *data)
> 
> 			if (ifrp != NULL)
> 			{
>-				ifr.ifr_addr = *sa;
>+				memcpy(&ifr.ifr_space, sa, sa->sa_len);

I think that this should be MIN(sa->sa_len, sizeof(ifr.ifr_space)) just
to be paranoid... Or even better:

_KASSERT(sa->sa_len < sizeof(ifr.ifr_space));

before the memcpy...

christos