*** /tmp/,RCSt1003037	Tue Jan 28 18:37:29 1992
--- if_loop.c	Wed Aug 21 17:40:45 1991
***************
*** 46,51 ****
--- 46,58 ----
  #include "../netns/ns_if.h"
  #endif
  
+ #include "bpfilter.h"
+ #if NBPFILTER > 0
+ #include <sys/time.h>
+ #include <net/bpf.h>
+ static caddr_t lo_bpf;
+ #endif
+ 
  #define	LOMTU	(1024+512)
  
  struct	ifnet loif;
***************
*** 61,66 ****
--- 68,76 ----
  	ifp->if_ioctl = loioctl;
  	ifp->if_output = looutput;
  	if_attach(ifp);
+ #if NBPFILTER > 0
+         bpfattach(&lo_bpf, ifp, DLT_NULL, sizeof(u_int));
+ #endif
  }
  
  looutput(ifp, m0, dst)
***************
*** 89,94 ****
--- 99,110 ----
  		m->m_next = m0;
  		m0 = m;
  	}
+ #if NBPFILTER > 0
+ 	if (lo_bpf) {
+ 		*(mtod(m0, u_int *)) = dst->sa_family;
+ 		bpf_mtap(lo_bpf, m0);
+ 	}
+ #endif
  	*(mtod(m0, struct ifnet **)) = ifp;
  	s = splimp();
  	ifp->if_opackets++;