o eliminate widespread on-stack mbuf use for bpf by introducing

  a new bpf_mtap2 routine that does the right thing for an mbuf
  and a variable-length chunk of data that should be prepended.
o while we're sweeping the drivers, use u_int32_t uniformly when
  when prepending the address family (several places were assuming
  sizeof(int) was 4)
o return M_ASSERTVALID to BPF_MTAP* now that all stack-allocated
  mbufs have been eliminated; this may better be moved to the bpf
  routines

Reviewed by:	arch@ and several others

1 files changed, 3 insertions, 15 deletions

diff --git a/sys/netinet/ip_gre.c b/sys/netinet/ip_gre.c
index fc6468b..05d3e09 100644
--- a/sys/netinet/ip_gre.c
+++ b/sys/netinet/ip_gre.c
@@ -196,14 +196,8 @@ gre_input2(struct mbuf *m ,int hlen, u_char proto)
 	m->m_pkthdr.len -= hlen;
 
 	if (sc->sc_if.if_bpf) {
-		struct mbuf m0;
 		u_int32_t af = AF_INET;
-
-		m0.m_next = m;
-		m0.m_len = 4;
-		m0.m_data = (char *)⁡
-
-		BPF_MTAP(&(sc->sc_if), &m0);
+		bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m);
 	}
 
 	m->m_pkthdr.rcvif = &sc->sc_if;
@@ -283,14 +277,8 @@ gre_mobile_input(m, va_alist)
 	ip->ip_sum = in_cksum(m, (ip->ip_hl << 2));
 
 	if (sc->sc_if.if_bpf) {
-		struct mbuf m0;
-		u_int af = AF_INET;
-
-		m0.m_next = m;
-		m0.m_len = 4;
-		m0.m_data = (char *)&af;
-
-		BPF_MTAP(&(sc->sc_if), &m0);
+		u_int32_t af = AF_INET;
+		bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m);
 	}
 
 	m->m_pkthdr.rcvif = &sc->sc_if;