3 files changed, 24 insertions, 0 deletions
diff --git a/c/src/exec/libnetworking/net/if.c b/c/src/exec/libnetworking/net/if.c
index af6f003de3..6f42b29903 100644
--- a/c/src/exec/libnetworking/net/if.c
+++ b/c/src/exec/libnetworking/net/if.c
@@ -664,6 +664,17 @@ ifioctl(so, cmd, data, p)
 
 	    }
 #endif
+
+	/*
+	 * RTEMS additions for setting/getting `tap' function
+	 */
+	case SIOCSIFTAP:
+		ifp->if_tap = ifr->ifr_tap;
+		return 0;
+
+	case SIOCGIFTAP:
+		ifr->ifr_tap = ifp->if_tap;
+		return 0;
 	}
 	return (0);
 }
diff --git a/c/src/exec/libnetworking/net/if.h b/c/src/exec/libnetworking/net/if.h
index acddd4f095..16785d7626 100644
--- a/c/src/exec/libnetworking/net/if.h
+++ b/c/src/exec/libnetworking/net/if.h
@@ -162,6 +162,8 @@ struct ifnet {
 		__P((struct ifnet *, struct mbuf *));
 	void	(*if_init)		/* Init routine */
 		__P((void *));
+	int	(*if_tap)		/* Packet filter routine */
+		(struct ifnet *, struct ether_header *, struct mbuf *);
 	struct	ifqueue if_snd;		/* output queue */
 	struct	ifqueue *if_poll_slowq;	/* input queue for slow devices */
 };
@@ -369,6 +371,7 @@ struct	ifreq {
 		int	ifru_phys;
 		int	ifru_media;
 		caddr_t	ifru_data;
+		int	(*ifru_tap)(struct ifnet *, struct ether_header *, struct mbuf *);
 	} ifr_ifru;
 #define	ifr_addr	ifr_ifru.ifru_addr	/* address */
 #define	ifr_dstaddr	ifr_ifru.ifru_dstaddr	/* other end of p-to-p link */
@@ -379,6 +382,7 @@ struct	ifreq {
 #define ifr_phys	ifr_ifru.ifru_phys	/* physical wire */
 #define ifr_media	ifr_ifru.ifru_media	/* physical media */
 #define	ifr_data	ifr_ifru.ifru_data	/* for use by interface */
+#define ifr_tap		ifr_ifru.ifru_tap	/* tap function */
 };
 
 struct ifaliasreq {
diff --git a/c/src/exec/libnetworking/net/if_ethersubr.c b/c/src/exec/libnetworking/net/if_ethersubr.c
index 4d1675ca3c..2a6446ebb6 100644
--- a/c/src/exec/libnetworking/net/if_ethersubr.c
+++ b/c/src/exec/libnetworking/net/if_ethersubr.c
@@ -483,6 +483,15 @@ ether_input(ifp, eh, m)
 	if (m->m_flags & (M_BCAST|M_MCAST))
 		ifp->if_imcasts++;
 
+	/*
+	 * RTEMS addition -- allow application to `tap into'
+	 * the incoming packet stream.
+	 */
+	if (ifp->if_tap && (*ifp->if_tap)(ifp, eh, m)) {
+		m_freem(m);
+		return;
+	}
+
 	ether_type = ntohs(eh->ether_type);
 
 	switch (ether_type) {