tcpdump'ing on vether(4)

[Martin Pieuchot]

I find it really useful to be able see output packets when tcpdump'ing
a vether(4) interface.

ok?

Index: net/if_vether.c
===================================================================
RCS file: /cvs/src/sys/net/if_vether.c,v
retrieving revision 1.23
diff -u -p -r1.23 if_vether.c
--- net/if_vether.c     14 Mar 2015 03:38:51 -0000      1.23
+++ net/if_vether.c     22 May 2015 13:19:30 -0000
@@ -29,6 +29,11 @@
 #include <netinet/in.h>
 #include <netinet/if_ether.h>
 
+#include "bpfilter.h"
+#if NBPFILTER > 0
+#include <net/bpf.h>
+#endif
+
 void   vetherattach(int);
 int    vetherioctl(struct ifnet *, u_long, caddr_t);
 void   vetherstart(struct ifnet *);
@@ -117,15 +122,17 @@ void
 vetherstart(struct ifnet *ifp)
 {
        struct mbuf             *m;
-       int                      s;
 
        for (;;) {
-               s = splnet();
                IFQ_DEQUEUE(&ifp->if_snd, m);
-               splx(s);
-
                if (m == NULL)
                        return;
+
+#if NBPFILTER > 0
+               if (ifp->if_bpf)
+                       bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
+#endif /* NBPFILTER > 0 */
+
                ifp->if_opackets++;
                m_freem(m);
        }