Add IFF_MONITOR support to gre(4).

Tested by:	Chip Marshall
MFC after:	1 week

2 files changed, 16 insertions, 0 deletions

diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index 3d33766..df0fc82 100644
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -341,6 +341,12 @@ gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
 	if (bpf_peers_present(ifp->if_bpf))
 		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
 
+	if ((ifp->if_flags & IFF_MONITOR) != 0) {
+		m_freem(m);
+		error = ENETDOWN;
+		goto end;
+	}
+
 	m->m_flags &= ~(M_BCAST|M_MCAST);
 
 	if (sc->g_proto == IPPROTO_MOBILE) {
diff --git a/sys/netinet/ip_gre.c b/sys/netinet/ip_gre.c
index 0735311..776820f 100644
--- a/sys/netinet/ip_gre.c
+++ b/sys/netinet/ip_gre.c
@@ -205,6 +205,11 @@ gre_input2(struct mbuf *m ,int hlen, u_char proto)
 		bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m);
 	}
 
+	if ((GRE2IFP(sc)->if_flags & IFF_MONITOR) != 0) {
+		m_freem(m);
+		return(NULL);
+	}
+
 	m->m_pkthdr.rcvif = GRE2IFP(sc);
 
 	netisr_queue(isr, m);
@@ -287,6 +292,11 @@ gre_mobile_input(struct mbuf *m, int hlen)
 		bpf_mtap2(GRE2IFP(sc)->if_bpf, &af, sizeof(af), m);
 	}
 
+	if ((GRE2IFP(sc)->if_flags & IFF_MONITOR) != 0) {
+		m_freem(m);
+		return;
+	}
+
 	m->m_pkthdr.rcvif = GRE2IFP(sc);
 
 	netisr_queue(NETISR_IP, m);