Add m_clrprotoflags() to clear protocol specific mbuf flags at up and

downwards layer crossings.

Consistently use it within IP, IPv6 and ethernet protocols.

Discussed with:	trociny, glebius

sys/net/if_ethersubr.c

@@ -774,7 +774,7 @@ ether_demux(struct ifnet *ifp, struct mbuf *m)
 	 * Strip off Ethernet header.
 	 */
 	m->m_flags &= ~M_VLANTAG;
-	m->m_flags &= ~(M_PROTOFLAGS);
+	m_clrprotoflags(m);
 	m_adj(m, ETHER_HDR_LEN);
 
 	/*

sys/net80211/ieee80211_hostap.c

@@ -355,7 +355,8 @@ hostap_deliver_data(struct ieee80211vap *vap,
 	struct ifnet *ifp = vap->iv_ifp;
 
 	/* clear driver/net80211 flags before passing up */
-	m->m_flags &= ~(M_80211_RX | M_MCAST | M_BCAST);
+	m->m_flags &= ~(M_MCAST | M_BCAST);
+	m_clrprotoflags(m);
 
 	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
 	    ("gack, opmode %d", vap->iv_opmode));

sys/net80211/ieee80211_input.c

@@ -250,7 +250,8 @@ ieee80211_deliver_data(struct ieee80211vap *vap,
 	struct ifnet *ifp = vap->iv_ifp;
 
 	/* clear driver/net80211 flags before passing up */
-	m->m_flags &= ~(M_80211_RX | M_MCAST | M_BCAST);
+	m->m_flags &= ~(M_MCAST | M_BCAST);
+	m_clrprotoflags(m);
 
 	/* NB: see hostap_deliver_data, this path doesn't handle hostap */
 	KASSERT(vap->iv_opmode != IEEE80211_M_HOSTAP, ("gack, hostap"));

sys/netinet/if_ether.c

@@ -281,6 +281,7 @@ arprequest(struct ifnet *ifp, const struct in_addr *sip,
 	sa.sa_family = AF_ARP;
 	sa.sa_len = 2;
 	m->m_flags |= M_BCAST;
+	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
 	(*ifp->if_output)(ifp, m, &sa, NULL);
 	ARPSTAT_INC(txrequests);
 }
@@ -784,6 +785,8 @@ in_arpinput(struct mbuf *m)
 			for (; m_hold != NULL; m_hold = m_hold_next) {
 				m_hold_next = m_hold->m_nextpkt;
 				m_hold->m_nextpkt = NULL;
+				/* Avoid confusing lower layers. */
+				m_clrprotoflags(m_hold);
 				(*ifp->if_output)(ifp, m_hold, &sa, NULL);
 			}
 		} else
@@ -888,6 +891,7 @@ in_arpinput(struct mbuf *m)
 	m->m_pkthdr.rcvif = NULL;
 	sa.sa_family = AF_ARP;
 	sa.sa_len = 2;
+	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
 	(*ifp->if_output)(ifp, m, &sa, NULL);
 	ARPSTAT_INC(txreplies);
 	return;

sys/netinet/igmp.c

@@ -3450,7 +3450,7 @@ igmp_intr(struct mbuf *m)
 	}
 
 	igmp_scrub_context(m0);
-	m->m_flags &= ~(M_PROTOFLAGS);
+	m_clrprotoflags(m);
 	m0->m_pkthdr.rcvif = V_loif;
 #ifdef MAC
 	mac_netinet_igmp_send(ifp, m0);

sys/netinet/ip_fastfwd.c

@@ -524,6 +524,10 @@ ip_fastforward(struct mbuf *m)
 
 	if (ip_len <= mtu ||
 	    (ifp->if_hwassist & CSUM_FRAGMENT && (ip_off & IP_DF) == 0)) {
+		/*
+		 * Avoid confusing lower layers.
+		 */
+		m_clrprotoflags(m);
 		/*
 		 * Send off the packet via outgoing interface
 		 */
@@ -553,6 +557,10 @@ ip_fastforward(struct mbuf *m)
 			do {
 				m0 = m->m_nextpkt;
 				m->m_nextpkt = NULL;
+				/*
+				 * Avoid confusing lower layers.
+				 */
+				m_clrprotoflags(m);
 
 				error = (*ifp->if_output)(ifp, m,
 					(struct sockaddr *)dst, &ro);

sys/netinet/ip_output.c

@@ -621,7 +621,7 @@ ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
 		 * Reset layer specific mbuf flags
 		 * to avoid confusing lower layers.
 		 */
-		m->m_flags &= ~(M_PROTOFLAGS);
+		m_clrprotoflags(m);
 		error = (*ifp->if_output)(ifp, m,
 		    (const struct sockaddr *)gw, ro);
 		goto done;
@@ -654,7 +654,7 @@ ip_output(struct mbuf *m, struct mbuf *opt, struct route *ro, int flags,
 			 * Reset layer specific mbuf flags
 			 * to avoid confusing upper layers.
 			 */
-			m->m_flags &= ~(M_PROTOFLAGS);
+			m_clrprotoflags(m);
 
 			error = (*ifp->if_output)(ifp, m,
 			    (const struct sockaddr *)gw, ro);

sys/netinet/sctp_os_bsd.h

@@ -444,12 +444,14 @@ typedef struct rtentry sctp_rtentry_t;
 	    local_stcb->sctp_ep && \
 	    local_stcb->sctp_ep->sctp_socket) \
 		o_flgs |= local_stcb->sctp_ep->sctp_socket->so_options & SO_DONTROUTE; \
+	m_clrprotoflags(o_pak); \
 	result = ip_output(o_pak, NULL, ro, o_flgs, 0, NULL); \
 }
 
 #define SCTP_IP6_OUTPUT(result, o_pak, ro, ifp, stcb, vrf_id) \
 { \
 	struct sctp_tcb *local_stcb = stcb; \
+	m_clrprotoflags(o_pak); \
 	if (local_stcb && local_stcb->sctp_ep) \
 		result = ip6_output(o_pak, \
 				    ((struct in6pcb *)(local_stcb->sctp_ep))->in6p_outputopts, \

sys/netinet6/ip6_mroute.c

@@ -1648,6 +1648,7 @@ phyint_send(struct ip6_hdr *ip6, struct mif6 *mifp, struct mbuf *m)
 		 * We just call if_output instead of nd6_output here, since
 		 * we need no ND for a multicast forwarded packet...right?
 		 */
+		m_clrprotoflags(m);	/* Avoid confusing lower layers. */
 		error = (*ifp->if_output)(ifp, mb_copy,
 		    (struct sockaddr *)&dst6, NULL);
 #ifdef MRT6DEBUG

sys/netinet6/mld6.c

@@ -3098,7 +3098,7 @@ mld_dispatch_packet(struct mbuf *m)
 	}
 
 	mld_scrub_context(m0);
-	m->m_flags &= ~(M_PROTOFLAGS);
+	m_clrprotoflags(m);
 	m0->m_pkthdr.rcvif = V_loif;
 
 	ip6 = mtod(m0, struct ip6_hdr *);

sys/netinet6/nd6.c

@@ -2082,8 +2082,7 @@ nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0,
 		}
 		return (error);
 	}
-	/* Reset layer specific mbuf flags to avoid confusing lower layers. */
+	m_clrprotoflags(m);	/* Avoid confusing lower layers. */
-	m->m_flags &= ~(M_PROTOFLAGS);  
 	if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
 		return ((*ifp->if_output)(origifp, m, (struct sockaddr *)dst,
 		    NULL));

sys/netinet6/send.c

@@ -180,6 +180,8 @@ send_output(struct mbuf *m, struct ifnet *ifp, int direction)
 		dst.sin6_len = sizeof(dst);
 		dst.sin6_addr = ip6->ip6_dst;
 
+		m_clrprotoflags(m);	/* Avoid confusing lower layers. */
+
 		/*
 		 * Output the packet as nd6.c:nd6_output_lle() would do.
 		 * The mbuf is always consumed, so we do not have to care

sys/netpfil/pf/pf.c

@@ -5310,7 +5310,7 @@ pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
 			ip->ip_sum = in_cksum(m0, ip->ip_hl << 2);
 			m0->m_pkthdr.csum_flags &= ~CSUM_IP;
 		}
-		m0->m_flags &= ~(M_PROTOFLAGS);
+		m_clrprotoflags(m0);	/* Avoid confusing lower layers. */
 		error = (*ifp->if_output)(ifp, m0, sintosa(&dst), NULL);
 		goto done;
 	}
@@ -5335,7 +5335,7 @@ pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
 		m1 = m0->m_nextpkt;
 		m0->m_nextpkt = NULL;
 		if (error == 0) {
-			m0->m_flags &= ~(M_PROTOFLAGS);
+			m_clrprotoflags(m0);
 			error = (*ifp->if_output)(ifp, m0, sintosa(&dst), NULL);
 		} else
 			m_freem(m0);

sys/ofed/drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -1442,7 +1442,7 @@ ipoib_input(struct ifnet *ifp, struct mbuf *m)
 	 * Strip off Infiniband header.
 	 */
 	m->m_flags &= ~M_VLANTAG;
-	m->m_flags &= ~(M_PROTOFLAGS);
+	m_clrprotoflags(m);
 	m_adj(m, IPOIB_HEADER_LEN);
 
 	if (IPOIB_IS_MULTICAST(eh->hwaddr)) {

sys/sys/mbuf.h

@@ -603,6 +603,13 @@ m_chtype(struct mbuf *m, short new_type)
 	m->m_type = new_type;
 }
 
+static __inline void
+m_clrprotoflags(struct mbuf *m)
+{
+
+	m->m_flags &= ~M_PROTOFLAGS;
+}
+
 static __inline struct mbuf *
 m_last(struct mbuf *m)
 {