introduce the ALTQ queue macros into sys/net files.

the new model removes direct references to the fields in ifp->if_snd,
and defines the following macros to manipulate ifp->if_snd.
  IFQ_ENQUEUE(ifq, m, pktattr, err)
  IFQ_DEQUEUE(ifq, m)
  IFQ_POLL(ifq, m)
  IFQ_PURGE(ifq)
  IFQ_IS_EMPTY(ifq)

the new model also enforces some rules regarding how to use these macros.
details are descrined in
http://www.csl.sony.co.jp/~kjc/software/altq-new-design.txt

14 files changed, 571 insertions, 166 deletions

diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index f84e8f5016b..49d697068c1 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bridgestp.c,v 1.6 2001/05/30 02:12:23 deraadt Exp $	*/
+/*	$OpenBSD: bridgestp.c,v 1.7 2001/06/27 06:07:37 kjc Exp $	*/
 
 /*
  * Copyright (c) 2000 Jason L. Wright (jason@thought.net)
@@ -224,7 +224,7 @@ bstp_send_config_bpdu(bif, cu)
 	struct mbuf *m;
 	struct ether_header eh;
 	struct bstp_cbpdu bpdu;
-	int s;
+	int s, error;
 
 	s = splimp();
 	ifp = bif->ifp;
@@ -234,6 +234,9 @@ bstp_send_config_bpdu(bif, cu)
 		splx(s);
 		return;
 	}
+#ifdef ALTQ
+	if (!ALTQ_IS_ENABLED(&ifp->if_snd))
+#endif
 	if (IF_QFULL(&ifp->if_snd)) {
 		splx(s);
 		return;
@@ -287,8 +290,8 @@ bstp_send_config_bpdu(bif, cu)
 	bcopy(&eh, m->m_data, sizeof(eh));
 	bcopy(&bpdu, m->m_data + sizeof(eh), sizeof(bpdu));
 
-	IF_ENQUEUE(&ifp->if_snd, m);
-	if ((ifp->if_flags & IFF_OACTIVE) == 0)
+	IFQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
+	if (error == 0 && (ifp->if_flags & IFF_OACTIVE) == 0)
 		(*ifp->if_start)(ifp);
 	splx(s);
 }
@@ -386,7 +389,7 @@ bstp_transmit_tcn(sc)
 	struct arpcom *arp = (struct arpcom *)ifp;
 	struct ether_header *eh;
 	struct mbuf *m;
-	int s;
+	int s, error;
 
 	MGETHDR(m, M_DONTWAIT, MT_DATA);
 	if (m == NULL)
@@ -410,10 +413,8 @@ bstp_transmit_tcn(sc)
 	s = splimp();
 	if ((ifp->if_flags & IFF_RUNNING) == 0)
 		goto out;
-	if (IF_QFULL(&ifp->if_snd))
-		goto out;
-	IF_ENQUEUE(&ifp->if_snd, m);
-	if ((ifp->if_flags & IFF_OACTIVE) == 0)
+	IFQ_ENQUEUE(&ifp->if_snd, m, NULL, error);
+	if (error == 0 && (ifp->if_flags & IFF_OACTIVE) == 0)
 		(*ifp->if_start)(ifp);
 	m = NULL;
 
diff --git a/sys/net/if_atmsubr.c b/sys/net/if_atmsubr.c
index c9437d5d1aa..10c13bbbb73 100644
--- a/sys/net/if_atmsubr.c
+++ b/sys/net/if_atmsubr.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: if_atmsubr.c,v 1.15 2001/06/15 03:38:33 itojun Exp $       */
+/*      $OpenBSD: if_atmsubr.c,v 1.16 2001/06/27 06:07:38 kjc Exp $       */
 
 /*
  *
@@ -107,17 +107,25 @@ atm_output(ifp, m0, dst, rt0)
 	struct rtentry *rt0;
 {
 	u_int16_t etype = 0;			/* if using LLC/SNAP */
-	int s, error = 0, sz;
+	int s, error = 0, sz, len;
 	struct atm_pseudohdr atmdst, *ad;
 	register struct mbuf *m = m0;
 	register struct rtentry *rt;
 	struct atmllc *atmllc;
 	u_int32_t atm_flags;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
 		senderr(ENETDOWN);
 
 	/*
+	 * if the queueing discipline needs packet classification,
+	 * do it before prepending link headers.
+	 */
+	IFQ_CLASSIFY(&ifp->if_snd, m,
+		     (dst != NULL ? dst->sa_family : AF_UNSPEC), &pktattr);
+
+	/*
 	 * check route
 	 */
 	if ((rt = rt0) != NULL) {
@@ -160,14 +168,6 @@ atm_output(ifp, m0, dst, rt0)
 				etype = ETHERTYPE_IP;
 			else
 				etype = ETHERTYPE_IPV6;
-# ifdef ATM_PVCEXT
-			if (ifp->if_flags & IFF_POINTOPOINT) {
-				/* pvc subinterface */
-				struct pvcsif *pvcsif = (struct pvcsif *)ifp;
-				atmdst = pvcsif->sif_aph;
-				break;
-			}
-# endif
 			if (!atmresolve(rt, m, dst, &atmdst)) {
 				m = NULL; 
 				/* XXX: atmresolve already free'd it */
@@ -235,15 +235,14 @@ atm_output(ifp, m0, dst, rt0)
 	 * Queue message on interface, and start output if interface
 	 * not yet active.
 	 */
-
+	len = m->m_pkthdr.len;
 	s = splimp();
-	if (IF_QFULL(&ifp->if_snd)) {
-		IF_DROP(&ifp->if_snd);
+	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
+	if (error) {
 		splx(s);
-		senderr(ENOBUFS);
+		return (error);
 	}
-	ifp->if_obytes += m->m_pkthdr.len;
-	IF_ENQUEUE(&ifp->if_snd, m);
+	ifp->if_obytes += len;
 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
 		(*ifp->if_start)(ifp);
 	splx(s);
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index 5690b6c5e76..cd3776b5b67 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_bridge.c,v 1.67 2001/06/26 18:17:53 deraadt Exp $	*/
+/*	$OpenBSD: if_bridge.c,v 1.68 2001/06/27 06:07:39 kjc Exp $	*/
 
 /*
  * Copyright (c) 1999, 2000 Jason L. Wright (jason@thought.net)
@@ -742,7 +742,9 @@ bridge_output(ifp, m, sa, rt)
 	struct ifnet *dst_if;
 	struct ether_addr *src, *dst;
 	struct bridge_softc *sc;
-	int s;
+	int s, error, len;
+	short mflags;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 #ifdef IPSEC
 	struct m_tag *mtag;
 #endif /* IPSEC */
@@ -806,6 +808,9 @@ bridge_output(ifp, m, sa, rt)
 			dst_if = p->ifp;
 			if ((dst_if->if_flags & IFF_RUNNING) == 0)
 				continue;
+#ifdef ALTQ
+			if (ALTQ_IS_ENABLED(&dst_if->if_snd) == 0)
+#endif
 			if (IF_QFULL(&dst_if->if_snd)) {
 				IF_DROP(&dst_if->if_snd);
 				sc->sc_if.if_oerrors++;
@@ -821,13 +826,22 @@ bridge_output(ifp, m, sa, rt)
 					continue;
 				}
 			}
-
+			len = mc->m_pkthdr.len;
+			mflags = mc->m_flags;
+#ifdef ALTQ
+			if (ALTQ_IS_ENABLED(&dst_if->if_snd))
+				altq_etherclassify(&dst_if->if_snd, mc, &pktattr);
+#endif
+			IFQ_ENQUEUE(&dst_if->if_snd, mc, &pktattr, error);
+			if (error) {
+				sc->sc_if.if_oerrors++;
+				continue;
+			}
 			sc->sc_if.if_opackets++;
-			sc->sc_if.if_obytes += mc->m_pkthdr.len;
-			dst_if->if_obytes += mc->m_pkthdr.len;
-			IF_ENQUEUE(&dst_if->if_snd, mc);
-			if (mc->m_flags & M_MCAST)
-				ifp->if_omcasts++;
+			sc->sc_if.if_obytes += len;
+			dst_if->if_obytes += len;
+			if (mflags & M_MCAST)
+				dst_if->if_omcasts++;
 			if ((dst_if->if_flags & IFF_OACTIVE) == 0)
 				(*dst_if->if_start)(dst_if);
 		}
@@ -843,18 +857,22 @@ sendunicast:
 		splx(s);
 		return (0);
 	}
-	if (IF_QFULL(&dst_if->if_snd)) {
-		IF_DROP(&dst_if->if_snd);
+	len = m->m_pkthdr.len;
+	mflags = m->m_flags;
+#ifdef ALTQ
+	if (ALTQ_IS_ENABLED(&dst_if->if_snd))
+		altq_etherclassify(&dst_if->if_snd, m, &pktattr);
+#endif
+	IFQ_ENQUEUE(&dst_if->if_snd, m, &pktattr, error);
+	if (error) {
 		sc->sc_if.if_oerrors++;
-		m_freem(m);
 		splx(s);
 		return (0);
 	}
 	sc->sc_if.if_opackets++;
-	sc->sc_if.if_obytes += m->m_pkthdr.len;
-	dst_if->if_obytes += m->m_pkthdr.len;
-	IF_ENQUEUE(&dst_if->if_snd, m);
-	if (m->m_flags & M_MCAST)
+	sc->sc_if.if_obytes += len;
+	dst_if->if_obytes += len;
+	if (mflags & M_MCAST)
 		dst_if->if_omcasts++;
 	if ((dst_if->if_flags & IFF_OACTIVE) == 0)
 		(*dst_if->if_start)(dst_if);
@@ -902,11 +920,13 @@ bridgeintr_frame(sc, m)
 	struct bridge_softc *sc;
 	struct mbuf *m;
 {
-	int s;
+	int s, error, len;
 	struct ifnet *src_if, *dst_if;
 	struct bridge_iflist *ifl;
 	struct ether_addr *dst, *src;
 	struct ether_header eh;
+	short mflags;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	if ((sc->sc_if.if_flags & IFF_RUNNING) == 0) {
 		m_freem(m);
@@ -1067,19 +1087,23 @@ bridgeintr_frame(sc, m)
 		m_freem(m);
 		return;
 	}
+#ifdef ALTQ
+	if (ALTQ_IS_ENABLED(&dst_if->if_snd))
+		altq_etherclassify(&dst_if->if_snd, m, &pktattr);
+#endif
+	len = m->m_pkthdr.len;
+	mflags = m->m_flags;
 	s = splimp();
-	if (IF_QFULL(&dst_if->if_snd)) {
-		IF_DROP(&dst_if->if_snd);
+	IFQ_ENQUEUE(&dst_if->if_snd, m, &pktattr, error);
+	if (error) {
 		sc->sc_if.if_oerrors++;
-		m_freem(m);
 		splx(s);
 		return;
 	}
 	sc->sc_if.if_opackets++;
-	sc->sc_if.if_obytes += m->m_pkthdr.len;
-	dst_if->if_obytes += m->m_pkthdr.len;
-	IF_ENQUEUE(&dst_if->if_snd, m);
-	if (m->m_flags & M_MCAST)
+	sc->sc_if.if_obytes += len;
+	dst_if->if_obytes += len;
+	if (mflags & M_MCAST)
 		dst_if->if_omcasts++;
 	if ((dst_if->if_flags & IFF_OACTIVE) == 0)
 		(*dst_if->if_start)(dst_if);
@@ -1245,7 +1269,9 @@ bridge_broadcast(sc, ifp, eh, m)
 	struct bridge_iflist *p;
 	struct mbuf *mc;
 	struct ifnet *dst_if;
-	int used = 0;
+	int error, len, used = 0;
+	short mflags;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	LIST_FOREACH(p, &sc->sc_iflist, next) {
 		/*
@@ -1268,6 +1294,9 @@ bridge_broadcast(sc, ifp, eh, m)
 		if ((dst_if->if_flags & IFF_RUNNING) == 0)
 			continue;
 
+#ifdef ALTQ
+		if (ALTQ_IS_ENABLED(&dst_if->if_snd) == 0)
+#endif
 		if (IF_QFULL(&dst_if->if_snd)) {
 			IF_DROP(&dst_if->if_snd);
 			sc->sc_if.if_oerrors++;
@@ -1294,11 +1323,19 @@ bridge_broadcast(sc, ifp, eh, m)
 			}
 		}
 
+#ifdef ALTQ
+		if (ALTQ_IS_ENABLED(&dst_if->if_snd))
+			altq_etherclassify(&dst_if->if_snd, mc, &pktattr);
+#endif
+		IFQ_ENQUEUE(&dst_if->if_snd, mc, &pktattr, error);
+		if (error) {
+			sc->sc_if.if_oerrors++;
+			continue;
+		}
 		sc->sc_if.if_opackets++;
-		sc->sc_if.if_obytes += mc->m_pkthdr.len;
-		dst_if->if_obytes += m->m_pkthdr.len;
-		IF_ENQUEUE(&dst_if->if_snd, mc);
-		if (mc->m_flags & M_MCAST)
+		sc->sc_if.if_obytes += len;
+		dst_if->if_obytes += len;
+		if (mflags & M_MCAST)
 			dst_if->if_omcasts++;
 		if ((dst_if->if_flags & IFF_OACTIVE) == 0)
 			(*dst_if->if_start)(dst_if);
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 325a7720cb7..622c73107b9 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ethersubr.c,v 1.51 2001/06/24 22:34:04 fgsch Exp $	*/
+/*	$OpenBSD: if_ethersubr.c,v 1.52 2001/06/27 06:07:40 kjc Exp $	*/
 /*	$NetBSD: if_ethersubr.c,v 1.19 1996/05/07 02:40:30 thorpej Exp $	*/
 
 /*
@@ -246,13 +246,15 @@ ether_output(ifp, m0, dst, rt0)
 	struct rtentry *rt0;
 {
 	u_int16_t etype;
-	int s, error = 0, hdrcmplt = 0;
+	int s, len, error = 0, hdrcmplt = 0;
  	u_char edst[6], esrc[6];
 	register struct mbuf *m = m0;
 	register struct rtentry *rt;
 	struct mbuf *mcopy = (struct mbuf *)0;
 	register struct ether_header *eh;
 	struct arpcom *ac = (struct arpcom *)ifp;
+	short mflags;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
 		senderr(ENETDOWN);
@@ -278,6 +280,13 @@ ether_output(ifp, m0, dst, rt0)
 			    time.tv_sec < rt->rt_rmx.rmx_expire)
 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
 	}
+
+	/*
+	 * if the queueing discipline needs packet classification,
+	 * do it before prepending link headers.
+	 */
+	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
+
 	switch (dst->sa_family) {
 
 #ifdef INET
@@ -560,19 +569,21 @@ ether_output(ifp, m0, dst, rt0)
 	}
 #endif
 
+	mflags = m->m_flags;
+	len = m->m_pkthdr.len;
 	s = splimp();
 	/*
 	 * Queue message on interface, and start output if interface
 	 * not yet active.
 	 */
-	if (IF_QFULL(&ifp->if_snd)) {
-		IF_DROP(&ifp->if_snd);
+	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
+	if (error) {
+		/* mbuf is already freed */
 		splx(s);
-		senderr(ENOBUFS);
+		return (error);
 	}
-	ifp->if_obytes += m->m_pkthdr.len;
-	IF_ENQUEUE(&ifp->if_snd, m);
-	if (m->m_flags & M_MCAST)
+	ifp->if_obytes += len + sizeof (struct ether_header);
+	if (mflags & M_MCAST)
 		ifp->if_omcasts++;
 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
 		(*ifp->if_start)(ifp);
@@ -585,6 +596,94 @@ bad:
 	return (error);
 }
 
+#ifdef ALTQ
+/*
+ * This routine is a slight hack to allow a packet to be classified
+ * if the Ethernet headers are present.  It will go away when ALTQ's
+ * classification engine understands link headers.
+ */
+void
+altq_etherclassify(struct ifaltq *ifq, struct mbuf *m,
+    struct altq_pktattr *pktattr)
+{
+	struct ether_header *eh;
+	u_int16_t ether_type;
+	int hlen, af, hdrsize;
+	caddr_t hdr;
+
+	hlen = ETHER_HDR_LEN;
+	eh = mtod(m, struct ether_header *);
+
+	ether_type = htons(eh->ether_type);
+
+	if (ether_type < ETHERMTU) {
+		/* LLC/SNAP */
+		struct llc *llc = (struct llc *)(eh + 1);
+		hlen += 8;
+
+		if (m->m_len < hlen ||
+		    llc->llc_dsap != LLC_SNAP_LSAP ||
+		    llc->llc_ssap != LLC_SNAP_LSAP ||
+		    llc->llc_control != LLC_UI) {
+			/* Not SNAP. */
+			goto bad;
+		}
+
+		ether_type = htons(llc->llc_un.type_snap.ether_type);
+	}
+
+	switch (ether_type) {
+	case ETHERTYPE_IP:
+		af = AF_INET;
+		hdrsize = 20;		/* sizeof(struct ip) */
+		break;
+
+	case ETHERTYPE_IPV6:
+		af = AF_INET6;
+		hdrsize = 40;		/* sizeof(struct ip6_hdr) */
+		break;
+
+	default:
+		af = AF_UNSPEC;
+		hdrsize = 0;
+		break;
+	}
+
+	if (m->m_len < (hlen + hdrsize)) {
+		/*
+		 * Ethernet and protocol header not in a single
+		 * mbuf.  We can't cope with this situation right
+		 * now (but it shouldn't ever happen, really, anyhow).
+		 * XXX Should use m_pulldown().
+		 */
+		printf("altq_etherclassify: headers span multiple mbufs: "
+		    "%d < %d\n", m->m_len, (hlen + hdrsize));
+		goto bad;
+	}
+
+	m->m_data += hlen;
+	m->m_len -= hlen;
+
+	hdr = mtod(m, caddr_t);
+
+	if (ALTQ_NEEDS_CLASSIFY(ifq))
+		pktattr->pattr_class =
+		    (*ifq->altq_classify)(ifq->altq_clfier, m, af);
+	pktattr->pattr_af = af;
+	pktattr->pattr_hdr = hdr;
+
+	m->m_data -= hlen;
+	m->m_len += hlen;
+
+	return;
+
+ bad:
+	pktattr->pattr_class = NULL;
+	pktattr->pattr_hdr = NULL;
+	pktattr->pattr_af = AF_UNSPEC;
+}
+#endif /* ALTQ */
+
 /*
  * Temporary function to migrate while
  * removing ether_header * from ether_input().
diff --git a/sys/net/if_fddisubr.c b/sys/net/if_fddisubr.c
index e4e9464ad79..3ae884a351c 100644
--- a/sys/net/if_fddisubr.c
+++ b/sys/net/if_fddisubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_fddisubr.c,v 1.24 2001/06/15 03:38:33 itojun Exp $	*/
+/*	$OpenBSD: if_fddisubr.c,v 1.25 2001/06/27 06:07:40 kjc Exp $	*/
 /*	$NetBSD: if_fddisubr.c,v 1.5 1996/05/07 23:20:21 christos Exp $	*/
 
 /*
@@ -150,13 +150,15 @@ fddi_output(ifp, m0, dst, rt0)
 	struct rtentry *rt0;
 {
 	u_int16_t type;
-	int s, error = 0, hdrcmplt = 0;
+	int s, len, error = 0, hdrcmplt = 0;
  	u_char edst[6], esrc[6];
 	register struct mbuf *m = m0;
 	register struct rtentry *rt;
 	struct mbuf *mcopy = (struct mbuf *)0;
 	register struct fddi_header *fh;
 	struct arpcom *ac = (struct arpcom *)ifp;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
+	short mflags;
 
 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
 		senderr(ENETDOWN);
@@ -182,6 +184,13 @@ fddi_output(ifp, m0, dst, rt0)
 			    time.tv_sec < rt->rt_rmx.rmx_expire)
 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
 	}
+
+	/*
+	 * If the queueing discipline needs packet classification,
+	 * do it before prepending link headers.
+	 */
+	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
+
 	switch (dst->sa_family) {
 
 #ifdef INET
@@ -432,23 +441,25 @@ fddi_output(ifp, m0, dst, rt0)
 	else
  		bcopy((caddr_t)ac->ac_enaddr, (caddr_t)fh->fddi_shost,
 		    sizeof(fh->fddi_shost));
+	mflags = m->m_flags;
+	len = m->m_pkthdr.len;
 	s = splimp();
 	/*
 	 * Queue message on interface, and start output if interface
 	 * not yet active.
 	 */
-	if (IF_QFULL(&ifp->if_snd)) {
-		IF_DROP(&ifp->if_snd);
+	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
+	if (error) {
+		/* mbuf is already freed */
 		splx(s);
-		senderr(ENOBUFS);
+		return (error);
 	}
-	ifp->if_obytes += m->m_pkthdr.len;
-	IF_ENQUEUE(&ifp->if_snd, m);
+	ifp->if_obytes += len;
+	if (mflags & M_MCAST)
+		ifp->if_omcasts++;
 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
 		(*ifp->if_start)(ifp);
 	splx(s);
-	if (m->m_flags & M_MCAST)
-		ifp->if_omcasts++;
 	return (error);
 
 bad:
diff --git a/sys/net/if_loop.c b/sys/net/if_loop.c
index 3d784315000..9c6d22d4014 100644
--- a/sys/net/if_loop.c
+++ b/sys/net/if_loop.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_loop.c,v 1.18 2001/06/15 03:38:34 itojun Exp $	*/
+/*	$OpenBSD: if_loop.c,v 1.19 2001/06/27 06:07:42 kjc Exp $	*/
 /*	$NetBSD: if_loop.c,v 1.15 1996/05/07 02:40:33 thorpej Exp $	*/
 
 /*
@@ -145,6 +145,10 @@ didn't get a copy, you may request one from <license@ipv6.nrl.navy.mil>.
 #define	LOMTU	(32768 +  MHLEN + MLEN)
 #endif
   
+#ifdef ALTQ
+static void lo_altqstart __P((struct ifnet *));
+#endif
+
 void
 loopattach(n)
 	int n;
@@ -168,6 +172,10 @@ loopattach(n)
 		ifp->if_type = IFT_LOOP;
 		ifp->if_hdrlen = sizeof(u_int32_t);
 		ifp->if_addrlen = 0;
+		IFQ_SET_READY(&ifp->if_snd);
+#ifdef ALTQ
+		ifp->if_start = lo_altqstart;
+#endif
 		if_attachhead(ifp);
 #if NBPFILTER > 0
 		bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t));
@@ -221,6 +229,37 @@ looutput(ifp, m, dst, rt)
 
 	ifp->if_opackets++;
 	ifp->if_obytes += m->m_pkthdr.len;
+#ifdef ALTQ
+	/*
+	 * altq for loop is just for debugging.
+	 * only used when called for loop interface (not for
+	 * a simplex interface).
+	 */
+	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd))
+	    && ifp->if_start == lo_altqstart) {
+		struct altq_pktattr pktattr;
+		int32_t *afp;
+	        int error;
+
+		/*
+		 * if the queueing discipline needs packet classification,
+		 * do it before prepending link headers.
+		 */
+		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
+
+		M_PREPEND(m, sizeof(int32_t), M_DONTWAIT);
+		if (m == 0)
+			return(ENOBUFS);
+		afp = mtod(m, int32_t *);
+		*afp = (int32_t)dst->sa_family;
+
+	        s = splimp();
+		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
+		(*ifp->if_start)(ifp);
+		splx(s);
+		return (error);
+	}
+#endif /* ALTQ */
 	switch (dst->sa_family) {
 
 #ifdef INET
@@ -280,6 +319,87 @@ looutput(ifp, m, dst, rt)
 	return (0);
 }
 
+#ifdef ALTQ
+static void
+lo_altqstart(ifp)
+	struct ifnet *ifp;
+{
+	struct ifqueue *ifq;
+	struct mbuf *m;
+	int32_t af, *afp;
+	int s, isr;
+	
+	while (1) {
+		s = splimp();
+		IFQ_DEQUEUE(&ifp->if_snd, m);
+		splx(s);
+		if (m == NULL)
+			return;
+
+		afp = mtod(m, int32_t *);
+		af = *afp;
+		m_adj(m, sizeof(int32_t));
+
+		switch (af) {
+#ifdef INET
+		case AF_INET:
+			ifq = &ipintrq;
+			isr = NETISR_IP;
+			break;
+#endif
+#ifdef INET6
+		case AF_INET6:
+			m->m_flags |= M_LOOP;
+			ifq = &ip6intrq;
+			isr = NETISR_IPV6;
+			break;
+#endif
+#ifdef IPX
+		case AF_IPX:
+			ifq = &ipxintrq;
+			isr = NETISR_IPX;
+			break;
+#endif
+#ifdef NS
+		case AF_NS:
+			ifq = &nsintrq;
+			isr = NETISR_NS;
+			break;
+#endif
+#ifdef ISO
+		case AF_ISO:
+			ifq = &clnlintrq;
+			isr = NETISR_ISO;
+			break;
+#endif
+#ifdef NETATALK
+		case AF_APPLETALK:
+			ifq = &atintrq2;
+			isr = NETISR_ATALK;
+			break;
+#endif NETATALK
+		default:
+			printf("lo_altqstart: can't handle af%d\n", af);
+			m_freem(m);
+			return;
+		}
+
+		s = splimp();
+		if (IF_QFULL(ifq)) {
+			IF_DROP(ifq);
+			m_freem(m);
+			splx(s);
+			return;
+		}
+		IF_ENQUEUE(ifq, m);
+		schednetisr(isr);
+		ifp->if_ipackets++;
+		ifp->if_ibytes += m->m_pkthdr.len;
+		splx(s);
+	}
+}
+#endif /* ALTQ */
+
 /* ARGSUSED */
 void
 lortrequest(cmd, rt, info)
diff --git a/sys/net/if_ppp.c b/sys/net/if_ppp.c
index 96fbe46d218..b057ba38669 100644
--- a/sys/net/if_ppp.c
+++ b/sys/net/if_ppp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ppp.c,v 1.22 2001/06/27 03:49:53 angelos Exp $	*/
+/*	$OpenBSD: if_ppp.c,v 1.23 2001/06/27 06:07:42 kjc Exp $	*/
 /*	$NetBSD: if_ppp.c,v 1.39 1997/05/17 21:11:59 christos Exp $	*/
 
 /*
@@ -199,10 +199,11 @@ pppattach()
 	sc->sc_if.if_hdrlen = PPP_HDRLEN;
 	sc->sc_if.if_ioctl = pppsioctl;
 	sc->sc_if.if_output = pppoutput;
-	sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
+	IFQ_SET_MAXLEN(&sc->sc_if.if_snd, IFQ_MAXLEN);
 	sc->sc_inq.ifq_maxlen = IFQ_MAXLEN;
 	sc->sc_fastq.ifq_maxlen = IFQ_MAXLEN;
 	sc->sc_rawq.ifq_maxlen = IFQ_MAXLEN;
+	IFQ_SET_READY(&sc->sc_if.if_snd);
 	if_attach(&sc->sc_if);
 #if NBPFILTER > 0
 	bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_PPP, PPP_HDRLEN);
@@ -636,6 +637,7 @@ pppoutput(ifp, m0, dst, rtp)
     enum NPmode mode;
     int len;
     struct mbuf *m;
+    ALTQ_DECL(struct altq_pktattr pktattr;)
 
     if (sc->sc_devp == NULL || (ifp->if_flags & IFF_RUNNING) == 0
 	|| ((ifp->if_flags & IFF_UP) == 0 && dst->sa_family != AF_UNSPEC)) {
@@ -643,6 +645,8 @@ pppoutput(ifp, m0, dst, rtp)
 	goto bad;
     }
 
+    IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr);
+
     /*
      * Compute PPP header.
      */
@@ -759,16 +763,29 @@ pppoutput(ifp, m0, dst, rtp)
 	m0->m_nextpkt = NULL;
 	sc->sc_npqtail = &m0->m_nextpkt;
     } else {
-	ifq = (m0->m_flags & M_HIGHPRI)? &sc->sc_fastq: &ifp->if_snd;
-	if (IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
-	    IF_DROP(ifq);
+	if ((m0->m_flags & M_HIGHPRI)
+#ifdef ALTQ
+	    && ALTQ_IS_ENABLED(&sc->sc_if.if_snd) == 0
+#endif
+	    ) {
+	    ifq = &sc->sc_fastq;
+	    if (IF_QFULL(ifq) && dst->sa_family != AF_UNSPEC) {
+		IF_DROP(ifq);
+		m_freem(m0);
+		error = ENOBUFS;
+	    }
+	    else {
+		IF_ENQUEUE(ifq, m0);
+		error = 0;
+	    }
+	} else
+	    IFQ_ENQUEUE(&sc->sc_if.if_snd, m0, &pktattr, error);
+	if (error) {
 	    splx(s);
 	    sc->sc_if.if_oerrors++;
 	    sc->sc_stats.ppp_oerrors++;
-	    error = ENOBUFS;
-	    goto bad;
+	    return (error);
 	}
-	IF_ENQUEUE(ifq, m0);
 	(*sc->sc_start)(sc);
     }
     ifp->if_opackets++;
@@ -794,6 +811,7 @@ ppp_requeue(sc)
     struct mbuf *m, **mpp;
     struct ifqueue *ifq;
     enum NPmode mode;
+    int error;
 
     for (mpp = &sc->sc_npqueue; (m = *mpp) != NULL; ) {
 	switch (PPP_PROTOCOL(mtod(m, u_char *))) {
@@ -811,13 +829,27 @@ ppp_requeue(sc)
 	     */
 	    *mpp = m->m_nextpkt;
 	    m->m_nextpkt = NULL;
-	    ifq = (m->m_flags & M_HIGHPRI)? &sc->sc_fastq: &sc->sc_if.if_snd;
-	    if (IF_QFULL(ifq)) {
-		IF_DROP(ifq);
+	    if ((m->m_flags & M_HIGHPRI)
+#ifdef ALTQ
+		&& ALTQ_IS_ENABLED(&sc->sc_if.if_snd) == 0
+#endif
+		) {
+		ifq = &sc->sc_fastq;
+		if (IF_QFULL(ifq)) {
+		    IF_DROP(ifq);
+		    m_freem(m);
+		    error = ENOBUFS;
+		}
+		else {
+		    IF_ENQUEUE(ifq, m);
+		    error = 0;
+		}
+	    } else
+		IFQ_ENQUEUE(&sc->sc_if.if_snd, m, NULL, error);
+	    if (error) {
 		sc->sc_if.if_oerrors++;
 		sc->sc_stats.ppp_oerrors++;
-	    } else
-		IF_ENQUEUE(ifq, m);
+	    }
 	    break;
 
 	case NPMODE_DROP:
@@ -869,7 +901,7 @@ ppp_dequeue(sc)
      */
     IF_DEQUEUE(&sc->sc_fastq, m);
     if (m == NULL)
-	IF_DEQUEUE(&sc->sc_if.if_snd, m);
+	IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
     if (m == NULL)
       return NULL;
 
@@ -995,7 +1027,7 @@ pppintr()
     s = splsoftnet();
     for (i = 0; i < NPPP; ++i, ++sc) {
 	if (!(sc->sc_flags & SC_TBUSY)
-	    && (sc->sc_if.if_snd.ifq_head || sc->sc_fastq.ifq_head)) {
+	    && (IFQ_IS_EMPTY(&sc->sc_if.if_snd) == 0 || sc->sc_fastq.ifq_head)) {
 	    s2 = splimp();
 	    sc->sc_flags |= SC_TBUSY;
 	    splx(s2);
diff --git a/sys/net/if_sl.c b/sys/net/if_sl.c
index 38a24740995..7b7898ac805 100644
--- a/sys/net/if_sl.c
+++ b/sys/net/if_sl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_sl.c,v 1.13 2001/06/15 03:38:34 itojun Exp $	*/
+/*	$OpenBSD: if_sl.c,v 1.14 2001/06/27 06:07:43 kjc Exp $	*/
 /*	$NetBSD: if_sl.c,v 1.39.4.1 1996/06/02 16:26:31 thorpej Exp $	*/
 
 /*
@@ -214,8 +214,9 @@ slattach(n)
 		sc->sc_if.if_type = IFT_SLIP;
 		sc->sc_if.if_ioctl = slioctl;
 		sc->sc_if.if_output = sloutput;
-		sc->sc_if.if_snd.ifq_maxlen = 50;
+		IFQ_SET_MAXLEN(&sc->sc_if.if_snd, 50);
 		sc->sc_fastq.ifq_maxlen = 32;
+		IFQ_SET_READY(&sc->sc_if.if_snd);
 		if_attach(&sc->sc_if);
 #if NBPFILTER > 0
 		bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
@@ -383,8 +384,10 @@ sloutput(ifp, m, dst, rtp)
 {
 	register struct sl_softc *sc = ifp->if_softc;
 	register struct ip *ip;
-	register struct ifqueue *ifq;
-	int s;
+	int s, error;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
+
+	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
 
 	/*
 	 * `Cannot happen' (see slioctl).  Someday we will extend
@@ -407,14 +410,11 @@ sloutput(ifp, m, dst, rtp)
 		m_freem(m);
 		return (EHOSTUNREACH);
 	}
-	ifq = &sc->sc_if.if_snd;
 	ip = mtod(m, struct ip *);
 	if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
 		m_freem(m);
 		return (ENETRESET);		/* XXX ? */
 	}
-	if (ip->ip_tos & IPTOS_LOWDELAY)
-		ifq = &sc->sc_fastq;
 	s = splimp();
 	if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
 		struct timeval tv;
@@ -426,14 +426,13 @@ sloutput(ifp, m, dst, rtp)
 			slstart(sc->sc_ttyp);
 		}
 	}
-	if (IF_QFULL(ifq)) {
-		IF_DROP(ifq);
-		m_freem(m);
+	IFQ_ENQUEUE(&sc->sc_if.if_snd, m, &pktattr, error);
+	if (error) {
 		splx(s);
 		sc->sc_if.if_oerrors++;
-		return (ENOBUFS);
+		return (error);
 	}
-	IF_ENQUEUE(ifq, m);
+
 	sc->sc_lastpacket = time;
 	if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0)
 		slstart(sc->sc_ttyp);
@@ -500,7 +499,7 @@ slstart(tp)
 		if (m)
 			sc->sc_if.if_omcasts++;		/* XXX */
 		else
-			IF_DEQUEUE(&sc->sc_if.if_snd, m);
+			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
 		splx(s);
 		if (m == NULL)
 			return;
diff --git a/sys/net/if_spppsubr.c b/sys/net/if_spppsubr.c
index 7a7f30dc6fe..55c69259192 100644
--- a/sys/net/if_spppsubr.c
+++ b/sys/net/if_spppsubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_spppsubr.c,v 1.8 2001/03/25 02:56:18 csapuntz Exp $	*/
+/*	$OpenBSD: if_spppsubr.c,v 1.9 2001/06/27 06:07:43 kjc Exp $	*/
 /*
  * Synchronous PPP/Cisco link level subroutines.
  * Keepalive protocol implemented in both Cisco and PPP modes.
@@ -639,8 +639,9 @@ sppp_output(struct ifnet *ifp, struct mbuf *m,
 {
 	struct sppp *sp = (struct sppp*) ifp;
 	struct ppp_header *h;
-	struct ifqueue *ifq;
-	int s, rv = 0;
+	struct ifqueue *ifq = NULL;
+	int s, len, rv = 0;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	s = splimp();
 
@@ -662,7 +663,12 @@ sppp_output(struct ifnet *ifp, struct mbuf *m,
 		s = splimp();
 	}
 
-	ifq = &ifp->if_snd;
+	/*
+	 * if the queueing discipline needs packet classification,
+	 * do it before prepending link headers.
+	 */
+	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
+
 #ifdef INET
 	/*
 	 * Put low delay, telnet, rlogin and ftp control packets
@@ -782,14 +788,28 @@ nosupport:
 	 * Queue message on interface, and start output if interface
 	 * not yet active.
 	 */
-	if (IF_QFULL (ifq)) {
-		IF_DROP (&ifp->if_snd);
-		m_freem (m);
+	len = m->m_pkthdr.len;
+	if (ifq != NULL
+#ifdef ALTQ
+	    && ALTQ_IS_ENABLED(&ifp->if_snd) == 0
+#endif
+		) {
+		if (IF_QFULL (ifq)) {
+			IF_DROP (&ifp->if_snd);
+			m_freem (m);
+			if (rv == 0)
+				rv = ENOBUFS;
+		}
+		IF_ENQUEUE (ifq, m);
+	}
+	else
+		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, rv);
+	if (rv != 0) {
 		++ifp->if_oerrors;
 		splx (s);
-		return (rv? rv: ENOBUFS);
+		return (rv);
 	}
-	IF_ENQUEUE (ifq, m);
+
 	if (! (ifp->if_flags & IFF_OACTIVE))
 		(*ifp->if_start) (ifp);
 
@@ -798,7 +818,7 @@ nosupport:
 	 * The packet length includes header, FCS and 1 flag,
 	 * according to RFC 1333.
 	 */
-	ifp->if_obytes += m->m_pkthdr.len + 3;
+	ifp->if_obytes += len + 3;
 	splx (s);
 	return (0);
 }
@@ -823,7 +843,7 @@ sppp_attach(struct ifnet *ifp)
 
 	sp->pp_if.if_type = IFT_PPP;
 	sp->pp_if.if_output = sppp_output;
-	sp->pp_if.if_snd.ifq_maxlen = 50;
+	IFQ_SET_MAXLEN(&sp->pp_if.if_snd, 50);
 	sp->pp_fastq.ifq_maxlen = 50;
 	sp->pp_cpq.ifq_maxlen = 50;
 	sp->pp_loopcnt = 0;
@@ -870,7 +890,7 @@ sppp_flush(struct ifnet *ifp)
 {
 	struct sppp *sp = (struct sppp*) ifp;
 
-	sppp_qflush (&sp->pp_if.if_snd);
+	IFQ_PURGE(&sp->pp_if.if_snd);
 	sppp_qflush (&sp->pp_fastq);
 	sppp_qflush (&sp->pp_cpq);
 }
@@ -886,7 +906,7 @@ sppp_isempty(struct ifnet *ifp)
 
 	s = splimp();
 	empty = !sp->pp_fastq.ifq_head && !sp->pp_cpq.ifq_head &&
-		!sp->pp_if.if_snd.ifq_head;
+		IFQ_IS_EMPTY(&sp->pp_if.if_snd);
 	splx(s);
 	return (empty);
 }
@@ -913,7 +933,7 @@ sppp_dequeue(struct ifnet *ifp)
 	    (sppp_ncp_check(sp) || (sp->pp_flags & PP_CISCO) != 0)) {
 		IF_DEQUEUE(&sp->pp_fastq, m);
 		if (m == NULL)
-			IF_DEQUEUE (&sp->pp_if.if_snd, m);
+			IFQ_DEQUEUE (&sp->pp_if.if_snd, m);
 	}
 	splx(s);
 	return m;
@@ -936,7 +956,7 @@ sppp_pick(struct ifnet *ifp)
 	    (sp->pp_phase == PHASE_NETWORK ||
 	     (sp->pp_flags & PP_CISCO) != 0))
 		if ((m = sp->pp_fastq.ifq_head) == NULL)
-			m = sp->pp_if.if_snd.ifq_head;
+			IFQ_POLL(&sp->pp_if.if_snd, m);
 	splx (s);
 	return (m);
 }
diff --git a/sys/net/if_strip.c b/sys/net/if_strip.c
index ccf994ce912..6b3d1c8a484 100644
--- a/sys/net/if_strip.c
+++ b/sys/net/if_strip.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_strip.c,v 1.14 2001/06/15 03:38:34 itojun Exp $	*/
+/*	$OpenBSD: if_strip.c,v 1.15 2001/06/27 06:07:44 kjc Exp $	*/
 /*	$NetBSD: if_strip.c,v 1.2.4.3 1996/08/03 00:58:32 jtc Exp $	*/
 /*	from: NetBSD: if_sl.c,v 1.38 1996/02/13 22:00:23 christos Exp $	*/
 
@@ -362,11 +362,12 @@ stripattach(n)
 		sc->sc_if.if_type = IFT_SLIP;
 		sc->sc_if.if_ioctl = stripioctl;
 		sc->sc_if.if_output = stripoutput;
-		sc->sc_if.if_snd.ifq_maxlen = 50;
+		IFQ_SET_MAXLEN(&sc->sc_if.if_snd, 50);
 		sc->sc_fastq.ifq_maxlen = 32;
 
 		sc->sc_if.if_watchdog = strip_watchdog;
 		sc->sc_if.if_timer = STRIP_WATCHDOG_INTERVAL;
+		IFQ_SET_READY(&sc->sc_if.if_snd);
 		if_attach(&sc->sc_if);
 #if NBPFILTER > 0
 		bpfattach(&sc->sc_bpf, &sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
@@ -715,7 +716,7 @@ stripoutput(ifp, m, dst, rt)
 	register u_char *dldst;		/* link-level next-hop */
 	int s;
 	u_char dl_addrbuf[STARMODE_ADDR_LEN+1];
-
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	/*
 	 * Verify tty line is up and alive.
@@ -779,13 +780,17 @@ stripoutput(ifp, m, dst, rt)
 		return (EAFNOSUPPORT);
 	}
 	
-	ifq = &sc->sc_if.if_snd;
+	ifq = NULL;
 	ip = mtod(m, struct ip *);
 	if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
 		m_freem(m);
 		return (ENETRESET);		/* XXX ? */
 	}
-	if (ip->ip_tos & IPTOS_LOWDELAY)
+	if ((ip->ip_tos & IPTOS_LOWDELAY)
+#ifdef ALTQ
+	    && ALTQ_IS_ENABLED(&sc->sc_if.if_snd) == 0
+#endif
+		)
 		ifq = &sc->sc_fastq;
 
 	/*
@@ -843,14 +848,22 @@ stripoutput(ifp, m, dst, rt)
 			stripstart(sc->sc_ttyp);
 		}
 	}
-	if (IF_QFULL(ifq)) {
-		IF_DROP(ifq);
-		m_freem(m);
+	if (ifq != NULL) {
+		if (IF_QFULL(ifq)) {
+			IF_DROP(ifq);
+			m_freem(m);
+			error = ENOBUFS;
+		} else {
+			IF_ENQUEUE(ifq, m);
+			error = 0;
+		}
+	} else
+		IFQ_ENQUEUE(&sc->sc_if.if_snd, m, &pktattr, error);
+	if (error) {
 		splx(s);
 		sc->sc_if.if_oerrors++;
-		return (ENOBUFS);
+		return (error);
 	}
-	IF_ENQUEUE(ifq, m);
 	sc->sc_lastpacket = time;
 	if ((sc->sc_oqlen = sc->sc_ttyp->t_outq.c_cc) == 0) {
 		stripstart(sc->sc_ttyp);
@@ -940,7 +953,7 @@ stripstart(tp)
 		if (m)
 			sc->sc_if.if_omcasts++;		/* XXX */
 		else
-			IF_DEQUEUE(&sc->sc_if.if_snd, m);
+			IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
 		splx(s);
 		if (m == NULL) {
 			return;
diff --git a/sys/net/if_tokensubr.c b/sys/net/if_tokensubr.c
index d0b85026f85..8b745ca24e6 100644
--- a/sys/net/if_tokensubr.c
+++ b/sys/net/if_tokensubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_tokensubr.c,v 1.3 2001/06/15 03:38:34 itojun Exp $	*/
+/*	$OpenBSD: if_tokensubr.c,v 1.4 2001/06/27 06:07:45 kjc Exp $	*/
 /*	$NetBSD: if_tokensubr.c,v 1.7 1999/05/30 00:39:07 bad Exp $	*/
 
 /*
@@ -140,7 +140,7 @@ token_output(ifp, m0, dst, rt0)
 	struct rtentry *rt0;
 {
 	u_int16_t etype;
-	int s, error = 0;
+	int s, len, error = 0;
 	u_char edst[ISO88025_ADDR_LEN];
 	register struct mbuf *m = m0;
 	register struct rtentry *rt;
@@ -152,6 +152,8 @@ token_output(ifp, m0, dst, rt0)
 	struct token_rif *rif = (struct  token_rif *)0;
 	struct token_rif bcastrif;
 	size_t riflen = 0;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
+	short mflags;
 
 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
 		senderr(ENETDOWN);
@@ -177,6 +179,13 @@ token_output(ifp, m0, dst, rt0)
 			    time.tv_sec < rt->rt_rmx.rmx_expire)
 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
 	}
+
+	/*
+	 * If the queueing discipline needs packet classification,
+	 * do it before prepending link headers.
+	 */
+	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
+
 	switch (dst->sa_family) {
 
 #ifdef INET
@@ -439,23 +448,25 @@ token_output(ifp, m0, dst, rt0)
 send:
 #endif /* 0 */
 
+	mflags = m->m_flags;
+	len = m->m_pkthdr.len;
 	s = splimp();
 	/*
 	 * Queue message on interface, and start output if interface
 	 * not yet active.
 	 */
-	if (IF_QFULL(&ifp->if_snd)) {
-		IF_DROP(&ifp->if_snd);
+	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
+	if (error) {
+		/* mbuf is already freed */
 		splx(s);
-		senderr(ENOBUFS);
+		return (error);
 	}
-	ifp->if_obytes += m->m_pkthdr.len;
-	IF_ENQUEUE(&ifp->if_snd, m);
+	ifp->if_obytes += len;
+	if (mflags & M_MCAST)
+		ifp->if_omcasts++;
 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
 		(*ifp->if_start)(ifp);
 	splx(s);
-	if (m->m_flags & M_MCAST)
-		ifp->if_omcasts++;
 	return (error);
 
 bad:
diff --git a/sys/net/if_tun.c b/sys/net/if_tun.c
index e9b7ff47528..e93689d2b8b 100644
--- a/sys/net/if_tun.c
+++ b/sys/net/if_tun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_tun.c,v 1.35 2001/06/15 03:38:34 itojun Exp $	*/
+/*	$OpenBSD: if_tun.c,v 1.36 2001/06/27 06:07:46 kjc Exp $	*/
 /*	$NetBSD: if_tun.c,v 1.24 1996/05/07 02:40:48 thorpej Exp $	*/
 
 /*
@@ -112,6 +112,9 @@ int	tunselect __P((dev_t, int, struct proc *));
 
 
 static int tuninit __P((struct tun_softc *));
+#ifdef ALTQ
+static void tunstart __P((struct ifnet *));
+#endif
 
 void
 tunattach(n)
@@ -132,9 +135,13 @@ tunattach(n)
 		ifp->if_mtu = TUNMTU;
 		ifp->if_ioctl = tun_ioctl;
 		ifp->if_output = tun_output;
+#ifdef ALTQ
+		ifp->if_start = tunstart;
+#endif
 		ifp->if_flags = IFF_POINTOPOINT;
 		ifp->if_type  = IFT_PROPVIRTUAL;
-		ifp->if_snd.ifq_maxlen = ifqmaxlen;
+		IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
+		IFQ_SET_READY(&ifp->if_snd);
 		ifp->if_hdrlen = sizeof(u_int32_t);
 		ifp->if_collisions = 0;
 		ifp->if_ierrors = 0;
@@ -194,7 +201,6 @@ tunclose(dev, flag, mode, p)
 	register int	unit, s;
 	struct tun_softc *tp;
 	struct ifnet	*ifp;
-	struct mbuf	*m;
 
 	if ((unit = minor(dev)) >= ntun)
 		return (ENXIO);
@@ -206,13 +212,9 @@ tunclose(dev, flag, mode, p)
 	/*
 	 * junk all pending output
 	 */
-	do {
-		s = splimp();
-		IF_DEQUEUE(&ifp->if_snd, m);
-		splx(s);
-		if (m)
-			m_freem(m);
-	} while (m);
+	s = splimp();
+	IFQ_PURGE(&ifp->if_snd);
+	splx(s);
 
 	if ((ifp->if_flags & IFF_UP) && !(tp->tun_flags & TUN_STAYUP)) {
 		s = splimp();
@@ -330,8 +332,9 @@ tun_output(ifp, m0, dst, rt)
 	struct rtentry *rt;
 {
 	struct tun_softc *tp = ifp->if_softc;
-	int		s;
+	int		s, len, error;
 	u_int32_t	*af;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	TUNDEBUG(("%s: tun_output\n", ifp->if_xname));
 
@@ -342,6 +345,12 @@ tun_output(ifp, m0, dst, rt)
 		return EHOSTDOWN;
 	}
 
+	/*
+	 * if the queueing discipline needs packet classification,
+	 * do it before prepending link headers.
+	 */
+	IFQ_CLASSIFY(&ifp->if_snd, m0, dst->sa_family, &pktattr);
+ 
 	M_PREPEND(m0, sizeof(*af), M_DONTWAIT);
 	af = mtod(m0, u_int32_t *);
 	*af = htonl(dst->sa_family);
@@ -351,19 +360,17 @@ tun_output(ifp, m0, dst, rt)
 		bpf_mtap(ifp->if_bpf, m0);
 #endif
 
+	len = m0->m_pkthdr.len + sizeof(*af);
 	s = splimp();
-	if (IF_QFULL(&ifp->if_snd)) {
-		IF_DROP(&ifp->if_snd);
-		m_freem(m0);
+	IFQ_ENQUEUE(&ifp->if_snd, m0, &pktattr, error);
+	if (error) {
 		splx(s);
 		ifp->if_collisions++;
-		return (ENOBUFS);
+		return (error);
 	}
-	IF_ENQUEUE(&ifp->if_snd, m0);
-
-	ifp->if_opackets++;
-	ifp->if_obytes += m0->m_pkthdr.len + sizeof(*af);
 	splx(s);
+	ifp->if_opackets++;
+	ifp->if_obytes += len;
 
 	if (tp->tun_flags & TUN_RWAIT) {
 		tp->tun_flags &= ~TUN_RWAIT;
@@ -510,7 +517,7 @@ tunread(dev, uio, ioflag)
 				splx(s);
 				return (error);
 			}
-		IF_DEQUEUE(&ifp->if_snd, m0);
+		IFQ_DEQUEUE(&ifp->if_snd, m0);
 		if (m0 == 0) {
 			if (tp->tun_flags & TUN_NBIO && ioflag & IO_NDELAY) {
 				splx(s);
@@ -716,3 +723,34 @@ tunselect(dev, rw, p)
 	TUNDEBUG(("%s: tunselect waiting\n", ifp->if_xname));
 	return 0;
 }
+
+#ifdef ALTQ
+/*
+ * Start packet transmission on the interface.
+ * when the interface queue is rate-limited by ALTQ or TBR,
+ * if_start is needed to drain packets from the queue in order
+ * to notify readers when outgoing packets become ready.
+ */
+static void
+tunstart(ifp)
+	struct ifnet *ifp;
+{
+	struct tun_softc *tp = ifp->if_softc;
+	struct mbuf *m;
+
+	if (!ALTQ_IS_ENABLED(&ifp->if_snd) && !TBR_IS_ENABLED(&ifp->if_snd))
+		return;
+
+	IFQ_POLL(&ifp->if_snd, m);
+	if (m != NULL) {
+		if (tp->tun_flags & TUN_RWAIT) {
+			tp->tun_flags &= ~TUN_RWAIT;
+			wakeup((caddr_t)tp);
+		}
+		if (tp->tun_flags & TUN_ASYNC && tp->tun_pgid)
+			csignal(tp->tun_pgid, SIGIO,
+			    tp->tun_siguid, tp->tun_sigeuid);
+		selwakeup(&tp->tun_rsel);
+	}
+}
+#endif
diff --git a/sys/net/if_vlan.c b/sys/net/if_vlan.c
index fcb27c76b22..5f7546803fa 100644
--- a/sys/net/if_vlan.c
+++ b/sys/net/if_vlan.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_vlan.c,v 1.23 2001/06/27 03:49:53 angelos Exp $ */
+/*	$OpenBSD: if_vlan.c,v 1.24 2001/06/27 06:07:46 kjc Exp $ */
 /*
  * Copyright 1998 Massachusetts Institute of Technology
  *
@@ -165,7 +165,8 @@ vlanattach(void *dummy)
 		ifp->if_start = vlan_start;
 		ifp->if_ioctl = vlan_ioctl;
 		ifp->if_output = ether_output;
-		ifp->if_snd.ifq_maxlen = ifqmaxlen;
+		IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
+		IFQ_SET_READY(&ifp->if_snd);
 		if_attach(ifp);
 		ether_ifattach(ifp);
 
@@ -182,13 +183,15 @@ vlan_start(struct ifnet *ifp)
 	struct ifnet *p;
 	struct ether_vlan_header *evl;
 	struct mbuf *m, *m0;
+	int error;
+	ALTQ_DECL(struct altq_pktattr pktattr;)
 
 	ifv = ifp->if_softc;
 	p = ifv->ifv_p;
 
 	ifp->if_flags |= IFF_OACTIVE;
 	for (;;) {
-		IF_DEQUEUE(&ifp->if_snd, m);
+		IFQ_DEQUEUE(&ifp->if_snd, m);
 		if (m == NULL)
 			break;
 
@@ -201,6 +204,26 @@ vlan_start(struct ifnet *ifp)
 			continue;
 		}
 
+#ifdef ALTQ
+		/*
+		 * If ALTQ is enabled on the parent interface, do
+		 * classification; the queueing discipline might
+		 * not require classification, but might require
+		 * the address family/header pointer in the pktattr.
+		 */
+		if (ALTQ_IS_ENABLED(&p->if_snd)) {
+			switch (p->if_type) {
+			case IFT_ETHER:
+				altq_etherclassify(&p->if_snd, m, &pktattr);
+				break;
+#ifdef DIAGNOSTIC
+			default:
+				panic("vlan_start: impossible (altq)");
+#endif
+			}
+		}
+#endif /* ALTQ */
+
 #if NBPFILTER > 0
 		if (ifp->if_bpf)
 			bpf_mtap(ifp->if_bpf, m);
@@ -271,17 +294,16 @@ vlan_start(struct ifnet *ifp)
 		 * Send it, precisely as ether_output() would have.
 		 * We are already running at splimp.
 		 */
-		if (IF_QFULL(&p->if_snd)) {
-			IF_DROP(&p->if_snd);
-				/* XXX stats */
-			ifp->if_oerrors++;
-			m_freem(m);
-			continue;
-		}
 		p->if_obytes += m->m_pkthdr.len;
 		if (m->m_flags & M_MCAST)
 			p->if_omcasts++;
-		IF_ENQUEUE(&p->if_snd, m);
+		IFQ_ENQUEUE(&p->if_snd, m, &pktattr, error);
+		if (error) {
+			/* mbuf is already freed */
+			ifp->if_oerrors++;
+			continue;
+		}
+
 		ifp->if_opackets++;
 		if ((p->if_flags & IFF_OACTIVE) == 0)
 			p->if_start(p);
diff --git a/sys/netinet/if_ether.h b/sys/netinet/if_ether.h
index 7abd64b245a..308effcfd9a 100644
--- a/sys/netinet/if_ether.h
+++ b/sys/netinet/if_ether.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ether.h,v 1.16 2001/06/23 21:32:26 fgsch Exp $	*/
+/*	$OpenBSD: if_ether.h,v 1.17 2001/06/27 06:07:47 kjc Exp $	*/
 /*	$NetBSD: if_ether.h,v 1.22 1996/05/11 13:00:00 mycroft Exp $	*/
 
 /*
@@ -285,6 +285,9 @@ void revarprequest __P((struct ifnet *));
 int revarpwhoarewe __P((struct ifnet *, struct in_addr *, struct in_addr *));
 int revarpwhoami __P((struct in_addr *, struct ifnet *));
 int db_show_arptab __P((void));
+#ifdef ALTQ
+void altq_etherclassify(struct ifaltq *, struct mbuf *, struct altq_pktattr *);
+#endif /* ALTQ */
 
 #else