Apply by doing:
cd /usr/src
patch -p0 < 002_ifmedia.patch
And then rebuild your kernel.
Index: sys/net/if.c
===================================================================
RCS file: /cvs/src/sys/net/if.c,v
retrieving revision 1.21
diff -u -r1.21 if.c
--- sys/net/if.c 1999/08/08 14:59:02 1.21
+++ sys/net/if.c 1999/11/11 01:22:15
@@ -622,8 +622,11 @@
case SIOCADDMULTI:
case SIOCDELMULTI:
+ case SIOCSIFMEDIA:
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
return (error);
+ /* FALLTHROUGH */
+ case SIOCGIFMEDIA:
if (ifp->if_ioctl == 0)
return (EOPNOTSUPP);
return ((*ifp->if_ioctl)(ifp, cmd, data));