MFC r284777:

ALTQ FAIRQ discipline import from DragonFLY

Differential Revision:	https://reviews.freebsd.org/D2847
Reviewed by:	glebius, wblock(manpage)
Approved by:	gnn(mentor)
Obtained from:	pfSense
Sponsored by:	Netgate

TAG:		FAIRQ

5 files changed, 1065 insertions, 1 deletions

diff --git a/sys/contrib/altq/altq/altq.h b/sys/contrib/altq/altq/altq.h
index c740ed3..1600ba8 100644
--- a/sys/contrib/altq/altq/altq.h
+++ b/sys/contrib/altq/altq/altq.h
@@ -63,7 +63,8 @@
 #define	ALTQT_BLUE		10	/* blue */
 #define	ALTQT_PRIQ		11	/* priority queue */
 #define	ALTQT_JOBS		12	/* JoBS */
-#define	ALTQT_MAX		13	/* should be max discipline type + 1 */
+#define	ALTQT_FAIRQ		13	/* fairq */
+#define	ALTQT_MAX		14	/* should be max discipline type + 1 */
 
 #ifdef ALTQ3_COMPAT
 struct	altqreq {
diff --git a/sys/contrib/altq/altq/altq_fairq.c b/sys/contrib/altq/altq/altq_fairq.c
new file mode 100644
index 0000000..038e6e1
--- /dev/null
+++ b/sys/contrib/altq/altq/altq_fairq.c
@@ -0,0 +1,889 @@
+/*
+ * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
+ * 
+ * This code is derived from software contributed to The DragonFly Project
+ * by Matthew Dillon <dillon@backplane.com>
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name of The DragonFly Project nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific, prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * 
+ * $DragonFly: src/sys/net/altq/altq_fairq.c,v 1.1 2008/04/06 18:58:15 dillon Exp $
+ * $FreeBSD$
+ */
+/*
+ * Matt: I gutted altq_priq.c and used it as a skeleton on which to build
+ * fairq.  The fairq algorithm is completely different then priq, of course,
+ * but because I used priq's skeleton I believe I should include priq's
+ * copyright.
+ *
+ * Copyright (C) 2000-2003
+ *	Sony Computer Science Laboratories Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY SONY CSL AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL SONY CSL OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * FAIRQ - take traffic classified by keep state (hashed into
+ * mbuf->m_pkthdr.altq_state_hash) and bucketize it.  Fairly extract
+ * the first packet from each bucket in a round-robin fashion.
+ *
+ * TODO - better overall qlimit support (right now it is per-bucket).
+ *	- NOTE: red etc is per bucket, not overall.
+ *	- better service curve support.
+ *
+ * EXAMPLE:
+ *
+ *  altq on em0 fairq bandwidth 650Kb queue { std, bulk }
+ *  queue std  priority 3 bandwidth 400Kb \
+ *	fairq (buckets 64, default, hogs 1Kb) qlimit 50
+ *  queue bulk priority 2 bandwidth 100Kb \
+ *	fairq (buckets 64, hogs 1Kb) qlimit 50
+ *
+ *  pass out on em0 from any to any keep state queue std
+ *  pass out on em0 inet proto tcp ..... port ... keep state queue bulk
+ */
+#include "opt_altq.h"
+#include "opt_inet.h"
+#include "opt_inet6.h"
+
+#ifdef ALTQ_FAIRQ  /* fairq is enabled in the kernel conf */
+
+#include <sys/param.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/sockio.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/errno.h>
+#include <sys/kernel.h>
+#include <sys/queue.h>
+
+#include <net/if.h>
+#include <netinet/in.h>
+
+#include <net/pfvar.h>
+#include <altq/altq.h>
+#include <altq/altq_fairq.h>
+
+/*
+ * function prototypes
+ */
+static int	fairq_clear_interface(struct fairq_if *);
+static int	fairq_request(struct ifaltq *, int, void *);
+static void	fairq_purge(struct fairq_if *);
+static struct fairq_class *fairq_class_create(struct fairq_if *, int, int, u_int, struct fairq_opts *, int);
+static int	fairq_class_destroy(struct fairq_class *);
+static int	fairq_enqueue(struct ifaltq *, struct mbuf *, struct altq_pktattr *);
+static struct mbuf *fairq_dequeue(struct ifaltq *, int);
+
+static int	fairq_addq(struct fairq_class *, struct mbuf *, u_int32_t);
+static struct mbuf *fairq_getq(struct fairq_class *, uint64_t);
+static struct mbuf *fairq_pollq(struct fairq_class *, uint64_t, int *);
+static fairq_bucket_t *fairq_selectq(struct fairq_class *, int);
+static void	fairq_purgeq(struct fairq_class *);
+
+static void	get_class_stats(struct fairq_classstats *, struct fairq_class *);
+static struct fairq_class *clh_to_clp(struct fairq_if *, uint32_t);
+
+int
+fairq_pfattach(struct pf_altq *a)
+{
+	struct ifnet *ifp;
+	int error;
+
+	if ((ifp = ifunit(a->ifname)) == NULL || a->altq_disc == NULL)
+		return (EINVAL);
+
+	error = altq_attach(&ifp->if_snd, ALTQT_FAIRQ, a->altq_disc,
+	    fairq_enqueue, fairq_dequeue, fairq_request, NULL, NULL);
+
+	return (error);
+}
+
+int
+fairq_add_altq(struct pf_altq *a)
+{
+	struct fairq_if *pif;
+	struct ifnet *ifp;
+
+	if ((ifp = ifunit(a->ifname)) == NULL)
+		return (EINVAL);
+	if (!ALTQ_IS_READY(&ifp->if_snd))
+		return (ENODEV);
+
+
+	pif = malloc(sizeof(struct fairq_if),
+			M_DEVBUF, M_WAITOK | M_ZERO);
+	pif->pif_bandwidth = a->ifbandwidth;
+	pif->pif_maxpri = -1;
+	pif->pif_ifq = &ifp->if_snd;
+
+	/* keep the state in pf_altq */
+	a->altq_disc = pif;
+
+	return (0);
+}
+
+int
+fairq_remove_altq(struct pf_altq *a)
+{
+	struct fairq_if *pif;
+
+	if ((pif = a->altq_disc) == NULL)
+		return (EINVAL);
+	a->altq_disc = NULL;
+
+	fairq_clear_interface(pif);
+
+	free(pif, M_DEVBUF);
+	return (0);
+}
+
+int
+fairq_add_queue(struct pf_altq *a)
+{
+	struct fairq_if *pif;
+	struct fairq_class *cl;
+
+	if ((pif = a->altq_disc) == NULL)
+		return (EINVAL);
+
+	/* check parameters */
+	if (a->priority >= FAIRQ_MAXPRI)
+		return (EINVAL);
+	if (a->qid == 0)
+		return (EINVAL);
+	if (pif->pif_classes[a->priority] != NULL)
+		return (EBUSY);
+	if (clh_to_clp(pif, a->qid) != NULL)
+		return (EBUSY);
+
+	cl = fairq_class_create(pif, a->priority, a->qlimit, a->bandwidth,
+			       &a->pq_u.fairq_opts, a->qid);
+	if (cl == NULL)
+		return (ENOMEM);
+
+	return (0);
+}
+
+int
+fairq_remove_queue(struct pf_altq *a)
+{
+	struct fairq_if *pif;
+	struct fairq_class *cl;
+
+	if ((pif = a->altq_disc) == NULL)
+		return (EINVAL);
+
+	if ((cl = clh_to_clp(pif, a->qid)) == NULL)
+		return (EINVAL);
+
+	return (fairq_class_destroy(cl));
+}
+
+int
+fairq_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
+{
+	struct fairq_if *pif;
+	struct fairq_class *cl;
+	struct fairq_classstats stats;
+	int error = 0;
+
+	if ((pif = altq_lookup(a->ifname, ALTQT_FAIRQ)) == NULL)
+		return (EBADF);
+
+	if ((cl = clh_to_clp(pif, a->qid)) == NULL)
+		return (EINVAL);
+
+	if (*nbytes < sizeof(stats))
+		return (EINVAL);
+
+	get_class_stats(&stats, cl);
+
+	if ((error = copyout((caddr_t)&stats, ubuf, sizeof(stats))) != 0)
+		return (error);
+	*nbytes = sizeof(stats);
+	return (0);
+}
+
+/*
+ * bring the interface back to the initial state by discarding
+ * all the filters and classes.
+ */
+static int
+fairq_clear_interface(struct fairq_if *pif)
+{
+	struct fairq_class *cl;
+	int pri;
+
+	/* clear out the classes */
+	for (pri = 0; pri <= pif->pif_maxpri; pri++) {
+		if ((cl = pif->pif_classes[pri]) != NULL)
+			fairq_class_destroy(cl);
+	}
+
+	return (0);
+}
+
+static int
+fairq_request(struct ifaltq *ifq, int req, void *arg)
+{
+	struct fairq_if *pif = (struct fairq_if *)ifq->altq_disc;
+
+	IFQ_LOCK_ASSERT(ifq);
+
+	switch (req) {
+	case ALTRQ_PURGE:
+		fairq_purge(pif);
+		break;
+	}
+	return (0);
+}
+
+/* discard all the queued packets on the interface */
+static void
+fairq_purge(struct fairq_if *pif)
+{
+	struct fairq_class *cl;
+	int pri;
+
+	for (pri = 0; pri <= pif->pif_maxpri; pri++) {
+		if ((cl = pif->pif_classes[pri]) != NULL && cl->cl_head)
+			fairq_purgeq(cl);
+	}
+	if (ALTQ_IS_ENABLED(pif->pif_ifq))
+		pif->pif_ifq->ifq_len = 0;
+}
+
+static struct fairq_class *
+fairq_class_create(struct fairq_if *pif, int pri, int qlimit,
+		   u_int bandwidth, struct fairq_opts *opts, int qid)
+{
+	struct fairq_class *cl;
+	int flags = opts->flags;
+	u_int nbuckets = opts->nbuckets;
+	int i;
+
+#ifndef ALTQ_RED
+	if (flags & FARF_RED) {
+#ifdef ALTQ_DEBUG
+		printf("fairq_class_create: RED not configured for FAIRQ!\n");
+#endif
+		return (NULL);
+	}
+#endif
+	if (nbuckets == 0)
+		nbuckets = 256;
+	if (nbuckets > FAIRQ_MAX_BUCKETS)
+		nbuckets = FAIRQ_MAX_BUCKETS;
+	/* enforce power-of-2 size */
+	while ((nbuckets ^ (nbuckets - 1)) != ((nbuckets << 1) - 1))
+		++nbuckets;
+
+	if ((cl = pif->pif_classes[pri]) != NULL) {
+		/* modify the class instead of creating a new one */
+		IFQ_LOCK(cl->cl_pif->pif_ifq);
+		if (cl->cl_head)
+			fairq_purgeq(cl);
+		IFQ_UNLOCK(cl->cl_pif->pif_ifq);
+#ifdef ALTQ_RIO
+		if (cl->cl_qtype == Q_RIO)
+			rio_destroy((rio_t *)cl->cl_red);
+#endif
+#ifdef ALTQ_RED
+		if (cl->cl_qtype == Q_RED)
+			red_destroy(cl->cl_red);
+#endif
+	} else {
+		cl = malloc(sizeof(struct fairq_class),
+				M_DEVBUF, M_WAITOK | M_ZERO);
+		cl->cl_nbuckets = nbuckets;
+		cl->cl_nbucket_mask = nbuckets - 1;
+
+		cl->cl_buckets = malloc(
+			sizeof(struct fairq_bucket) * cl->cl_nbuckets,
+			M_DEVBUF, M_WAITOK | M_ZERO);
+		cl->cl_head = NULL;
+	}
+
+	pif->pif_classes[pri] = cl;
+	if (flags & FARF_DEFAULTCLASS)
+		pif->pif_default = cl;
+	if (qlimit == 0)
+		qlimit = 50;  /* use default */
+	cl->cl_qlimit = qlimit;
+	for (i = 0; i < cl->cl_nbuckets; ++i) {
+		qlimit(&cl->cl_buckets[i].queue) = qlimit;
+	}
+	cl->cl_bandwidth = bandwidth / 8;
+	cl->cl_qtype = Q_DROPTAIL;
+	cl->cl_flags = flags & FARF_USERFLAGS;
+	cl->cl_pri = pri;
+	if (pri > pif->pif_maxpri)
+		pif->pif_maxpri = pri;
+	cl->cl_pif = pif;
+	cl->cl_handle = qid;
+	cl->cl_hogs_m1 = opts->hogs_m1 / 8;
+	cl->cl_lssc_m1 = opts->lssc_m1 / 8;	/* NOT YET USED */
+
+#ifdef ALTQ_RED
+	if (flags & (FARF_RED|FARF_RIO)) {
+		int red_flags, red_pkttime;
+
+		red_flags = 0;
+		if (flags & FARF_ECN)
+			red_flags |= REDF_ECN;
+#ifdef ALTQ_RIO
+		if (flags & FARF_CLEARDSCP)
+			red_flags |= RIOF_CLEARDSCP;
+#endif
+		if (pif->pif_bandwidth < 8)
+			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
+		else
+			red_pkttime = (int64_t)pif->pif_ifq->altq_ifp->if_mtu
+			  * 1000 * 1000 * 1000 / (pif->pif_bandwidth / 8);
+#ifdef ALTQ_RIO
+		if (flags & FARF_RIO) {
+			cl->cl_red = (red_t *)rio_alloc(0, NULL,
+						red_flags, red_pkttime);
+			if (cl->cl_red != NULL)
+				cl->cl_qtype = Q_RIO;
+		} else
+#endif
+		if (flags & FARF_RED) {
+			cl->cl_red = red_alloc(0, 0,
+			    cl->cl_qlimit * 10/100,
+			    cl->cl_qlimit * 30/100,
+			    red_flags, red_pkttime);
+			if (cl->cl_red != NULL)
+				cl->cl_qtype = Q_RED;
+		}
+	}
+#endif /* ALTQ_RED */
+
+	return (cl);
+
+err_buckets:
+	if (cl->cl_buckets != NULL)
+		free(cl->cl_buckets, M_DEVBUF);
+err_ret:
+        if (cl->cl_red != NULL) {
+#ifdef ALTQ_RIO
+                if (cl->cl_qtype == Q_RIO)
+                        rio_destroy((rio_t *)cl->cl_red);
+#endif
+#ifdef ALTQ_RED
+               if (cl->cl_qtype == Q_RED)
+                       red_destroy(cl->cl_red);
+#endif
+        }
+        if (cl != NULL)
+                free(cl, M_DEVBUF);
+        return (NULL);
+}
+
+static int
+fairq_class_destroy(struct fairq_class *cl)
+{
+	struct fairq_if *pif;
+	int pri;
+
+	IFQ_LOCK(cl->cl_pif->pif_ifq);
+
+	if (cl->cl_head)
+		fairq_purgeq(cl);
+
+	pif = cl->cl_pif;
+	pif->pif_classes[cl->cl_pri] = NULL;
+	if (pif->pif_poll_cache == cl)
+		pif->pif_poll_cache = NULL;
+	if (pif->pif_maxpri == cl->cl_pri) {
+		for (pri = cl->cl_pri; pri >= 0; pri--)
+			if (pif->pif_classes[pri] != NULL) {
+				pif->pif_maxpri = pri;
+				break;
+			}
+		if (pri < 0)
+			pif->pif_maxpri = -1;
+	}
+	IFQ_UNLOCK(cl->cl_pif->pif_ifq);
+
+	if (cl->cl_red != NULL) {
+#ifdef ALTQ_RIO
+		if (cl->cl_qtype == Q_RIO)
+			rio_destroy((rio_t *)cl->cl_red);
+#endif
+#ifdef ALTQ_RED
+		if (cl->cl_qtype == Q_RED)
+			red_destroy(cl->cl_red);
+#endif
+	}
+	free(cl->cl_buckets, M_DEVBUF);
+	free(cl, M_DEVBUF);
+
+	return (0);
+}
+
+/*
+ * fairq_enqueue is an enqueue function to be registered to
+ * (*altq_enqueue) in struct ifaltq.
+ */
+static int
+fairq_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr)
+{
+	struct fairq_if *pif = (struct fairq_if *)ifq->altq_disc;
+	struct fairq_class *cl = NULL; /* Make compiler happy */
+	struct pf_mtag *t;
+	u_int32_t qid_hash = 0;
+	int len;
+
+	IFQ_LOCK_ASSERT(ifq);
+
+	/* grab class set by classifier */
+	if ((m->m_flags & M_PKTHDR) == 0) {
+		/* should not happen */
+		printf("altq: packet for %s does not have pkthdr\n",
+			ifq->altq_ifp->if_xname);
+		m_freem(m);
+		return (ENOBUFS);
+	}
+
+	if ((t = pf_find_mtag(m)) != NULL) {
+		cl = clh_to_clp(pif, t->qid);
+		qid_hash = t->qid_hash;
+	}
+	if (cl == NULL) {
+		cl = pif->pif_default;
+		if (cl == NULL) {
+			m_freem(m);
+			return (ENOBUFS);
+		}
+	}
+	cl->cl_flags |= FARF_HAS_PACKETS;
+	cl->cl_pktattr = NULL;
+	len = m_pktlen(m);
+	if (fairq_addq(cl, m, qid_hash) != 0) {
+		/* drop occurred.  mbuf was freed in fairq_addq. */
+		PKTCNTR_ADD(&cl->cl_dropcnt, len);
+		return (ENOBUFS);
+	}
+	IFQ_INC_LEN(ifq);
+
+	return (0);
+}
+
+/*
+ * fairq_dequeue is a dequeue function to be registered to
+ * (*altq_dequeue) in struct ifaltq.
+ *
+ * note: ALTDQ_POLL returns the next packet without removing the packet
+ *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
+ *	ALTDQ_REMOVE must return the same packet if called immediately
+ *	after ALTDQ_POLL.
+ */
+static struct mbuf *
+fairq_dequeue(struct ifaltq *ifq, int op)
+{
+	struct fairq_if *pif = (struct fairq_if *)ifq->altq_disc;
+	struct fairq_class *cl;
+	struct fairq_class *best_cl;
+	struct mbuf *best_m;
+	struct mbuf *m = NULL;
+	uint64_t cur_time = read_machclk();
+	int pri;
+	int hit_limit;
+
+	IFQ_LOCK_ASSERT(ifq);
+
+	if (IFQ_IS_EMPTY(ifq)) {
+		return (NULL);
+	}
+
+	if (pif->pif_poll_cache && op == ALTDQ_REMOVE) {
+		best_cl = pif->pif_poll_cache;
+		m = fairq_getq(best_cl, cur_time);
+		pif->pif_poll_cache = NULL;
+		if (m) {
+			IFQ_DEC_LEN(ifq);
+			PKTCNTR_ADD(&best_cl->cl_xmitcnt, m_pktlen(m));
+			return (m);
+		}
+	} else {
+		best_cl = NULL;
+		best_m = NULL;
+
+		for (pri = pif->pif_maxpri;  pri >= 0; pri--) {
+			if ((cl = pif->pif_classes[pri]) == NULL)
+				continue;
+			if ((cl->cl_flags & FARF_HAS_PACKETS) == 0)
+				continue;
+			m = fairq_pollq(cl, cur_time, &hit_limit);
+			if (m == NULL) {
+				cl->cl_flags &= ~FARF_HAS_PACKETS;
+				continue;
+			}
+
+			/*
+			 * Only override the best choice if we are under
+			 * the BW limit.
+			 */
+			if (hit_limit == 0 || best_cl == NULL) {
+				best_cl = cl;
+				best_m = m;
+			}
+
+			/*
+			 * Remember the highest priority mbuf in case we
+			 * do not find any lower priority mbufs.
+			 */
+			if (hit_limit)
+				continue;
+			break;
+		}
+		if (op == ALTDQ_POLL) {
+			pif->pif_poll_cache = best_cl;
+			m = best_m;
+		} else if (best_cl) {
+			m = fairq_getq(best_cl, cur_time);
+			if (m != NULL) {
+				IFQ_DEC_LEN(ifq);
+				PKTCNTR_ADD(&best_cl->cl_xmitcnt, m_pktlen(m));
+			}
+		} 
+		return (m);
+	}
+	return (NULL);
+}
+
+static int
+fairq_addq(struct fairq_class *cl, struct mbuf *m, u_int32_t bucketid)
+{
+	fairq_bucket_t *b;
+	u_int hindex;
+	uint64_t bw;
+
+	/*
+	 * If the packet doesn't have any keep state put it on the end of
+	 * our queue.  XXX this can result in out of order delivery.
+	 */
+	if (bucketid == 0) {
+		if (cl->cl_head)
+			b = cl->cl_head->prev;
+		else
+			b = &cl->cl_buckets[0];
+	} else {
+		hindex = bucketid & cl->cl_nbucket_mask;
+		b = &cl->cl_buckets[hindex];
+	}
+
+	/*
+	 * Add the bucket to the end of the circular list of active buckets.
+	 *
+	 * As a special case we add the bucket to the beginning of the list
+	 * instead of the end if it was not previously on the list and if
+	 * its traffic is less then the hog level.
+	 */
+	if (b->in_use == 0) {
+		b->in_use = 1;
+		if (cl->cl_head == NULL) {
+			cl->cl_head = b;
+			b->next = b;
+			b->prev = b;
+		} else {
+			b->next = cl->cl_head;
+			b->prev = cl->cl_head->prev;
+			b->prev->next = b;
+			b->next->prev = b;
+
+			if (b->bw_delta && cl->cl_hogs_m1) {
+				bw = b->bw_bytes * machclk_freq / b->bw_delta;
+				if (bw < cl->cl_hogs_m1)
+					cl->cl_head = b;
+			}
+		}
+	}
+
+#ifdef ALTQ_RIO
+	if (cl->cl_qtype == Q_RIO)
+		return rio_addq((rio_t *)cl->cl_red, &b->queue, m, cl->cl_pktattr);
+#endif
+#ifdef ALTQ_RED
+	if (cl->cl_qtype == Q_RED)
+		return red_addq(cl->cl_red, &b->queue, m, cl->cl_pktattr);
+#endif
+	if (qlen(&b->queue) >= qlimit(&b->queue)) {
+		m_freem(m);
+		return (-1);
+	}
+
+	if (cl->cl_flags & FARF_CLEARDSCP)
+		write_dsfield(m, cl->cl_pktattr, 0);
+
+	_addq(&b->queue, m);
+
+	return (0);
+}
+
+static struct mbuf *
+fairq_getq(struct fairq_class *cl, uint64_t cur_time)
+{
+	fairq_bucket_t *b;
+	struct mbuf *m;
+
+	b = fairq_selectq(cl, 0);
+	if (b == NULL)
+		m = NULL;
+#ifdef ALTQ_RIO
+	else if (cl->cl_qtype == Q_RIO)
+		m = rio_getq((rio_t *)cl->cl_red, &b->queue);
+#endif
+#ifdef ALTQ_RED
+	else if (cl->cl_qtype == Q_RED)
+		m = red_getq(cl->cl_red, &b->queue);
+#endif
+	else
+		m = _getq(&b->queue);
+
+	/*
+	 * Calculate the BW change
+	 */
+	if (m != NULL) {
+		uint64_t delta;
+
+		/*
+		 * Per-class bandwidth calculation
+		 */
+		delta = (cur_time - cl->cl_last_time);
+		if (delta > machclk_freq * 8)
+			delta = machclk_freq * 8;
+		cl->cl_bw_delta += delta;
+		cl->cl_bw_bytes += m->m_pkthdr.len;
+		cl->cl_last_time = cur_time;
+		cl->cl_bw_delta -= cl->cl_bw_delta >> 3;
+		cl->cl_bw_bytes -= cl->cl_bw_bytes >> 3;
+
+		/*
+		 * Per-bucket bandwidth calculation
+		 */
+		delta = (cur_time - b->last_time);
+		if (delta > machclk_freq * 8)
+			delta = machclk_freq * 8;
+		b->bw_delta += delta;
+		b->bw_bytes += m->m_pkthdr.len;
+		b->last_time = cur_time;
+		b->bw_delta -= b->bw_delta >> 3;
+		b->bw_bytes -= b->bw_bytes >> 3;
+	}
+	return(m);
+}
+
+/*
+ * Figure out what the next packet would be if there were no limits.  If
+ * this class hits its bandwidth limit *hit_limit is set to no-zero, otherwise
+ * it is set to 0.  A non-NULL mbuf is returned either way.
+ */
+static struct mbuf *
+fairq_pollq(struct fairq_class *cl, uint64_t cur_time, int *hit_limit)
+{
+	fairq_bucket_t *b;
+	struct mbuf *m;
+	uint64_t delta;
+	uint64_t bw;
+
+	*hit_limit = 0;
+	b = fairq_selectq(cl, 1);
+	if (b == NULL)
+		return(NULL);
+	m = qhead(&b->queue);
+
+	/*
+	 * Did this packet exceed the class bandwidth?  Calculate the
+	 * bandwidth component of the packet.
+	 *
+	 * - Calculate bytes per second
+	 */
+	delta = cur_time - cl->cl_last_time;
+	if (delta > machclk_freq * 8)
+		delta = machclk_freq * 8;
+	cl->cl_bw_delta += delta;
+	cl->cl_last_time = cur_time;
+	if (cl->cl_bw_delta) {
+		bw = cl->cl_bw_bytes * machclk_freq / cl->cl_bw_delta;
+
+		if (bw > cl->cl_bandwidth)
+			*hit_limit = 1;
+#ifdef ALTQ_DEBUG
+		printf("BW %6lld relative to %6u %d queue %p\n",
+			bw, cl->cl_bandwidth, *hit_limit, b);
+#endif
+	}
+	return(m);
+}
+
+/*
+ * Locate the next queue we want to pull a packet out of.  This code
+ * is also responsible for removing empty buckets from the circular list.
+ */
+static
+fairq_bucket_t *
+fairq_selectq(struct fairq_class *cl, int ispoll)
+{
+	fairq_bucket_t *b;
+	uint64_t bw;
+
+	if (ispoll == 0 && cl->cl_polled) {
+		b = cl->cl_polled;
+		cl->cl_polled = NULL;
+		return(b);
+	}
+
+	while ((b = cl->cl_head) != NULL) {
+		/*
+		 * Remove empty queues from consideration
+		 */
+		if (qempty(&b->queue)) {
+			b->in_use = 0;
+			cl->cl_head = b->next;
+			if (cl->cl_head == b) {
+				cl->cl_head = NULL;
+			} else {
+				b->next->prev = b->prev;
+				b->prev->next = b->next;
+			}
+			continue;
+		}
+
+		/*
+		 * Advance the round robin.  Queues with bandwidths less
+		 * then the hog bandwidth are allowed to burst.
+		 */
+		if (cl->cl_hogs_m1 == 0) {
+			cl->cl_head = b->next;
+		} else if (b->bw_delta) {
+			bw = b->bw_bytes * machclk_freq / b->bw_delta;
+			if (bw >= cl->cl_hogs_m1) {
+				cl->cl_head = b->next;
+			}
+			/*
+			 * XXX TODO - 
+			 */
+		}
+
+		/*
+		 * Return bucket b.
+		 */
+		break;
+	}
+	if (ispoll)
+		cl->cl_polled = b;
+	return(b);
+}
+
+static void
+fairq_purgeq(struct fairq_class *cl)
+{
+	fairq_bucket_t *b;
+	struct mbuf *m;
+
+	while ((b = fairq_selectq(cl, 0)) != NULL) {
+		while ((m = _getq(&b->queue)) != NULL) {
+			PKTCNTR_ADD(&cl->cl_dropcnt, m_pktlen(m));
+			m_freem(m);
+		}
+		ASSERT(qlen(&b->queue) == 0);
+	}
+}
+
+static void
+get_class_stats(struct fairq_classstats *sp, struct fairq_class *cl)
+{
+	fairq_bucket_t *b;
+
+	sp->class_handle = cl->cl_handle;
+	sp->qlimit = cl->cl_qlimit;
+	sp->xmit_cnt = cl->cl_xmitcnt;
+	sp->drop_cnt = cl->cl_dropcnt;
+	sp->qtype = cl->cl_qtype;
+	sp->qlength = 0;
+
+	if (cl->cl_head) {
+		b = cl->cl_head;
+		do {
+			sp->qlength += qlen(&b->queue);
+			b = b->next;
+		} while (b != cl->cl_head);
+	}
+
+#ifdef ALTQ_RED
+	if (cl->cl_qtype == Q_RED)
+		red_getstats(cl->cl_red, &sp->red[0]);
+#endif
+#ifdef ALTQ_RIO
+	if (cl->cl_qtype == Q_RIO)
+		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
+#endif
+}
+
+/* convert a class handle to the corresponding class pointer */
+static struct fairq_class *
+clh_to_clp(struct fairq_if *pif, uint32_t chandle)
+{
+	struct fairq_class *cl;
+	int idx;
+
+	if (chandle == 0)
+		return (NULL);
+
+	for (idx = pif->pif_maxpri; idx >= 0; idx--)
+		if ((cl = pif->pif_classes[idx]) != NULL &&
+		    cl->cl_handle == chandle)
+			return (cl);
+
+	return (NULL);
+}
+
+#endif /* ALTQ_FAIRQ */
diff --git a/sys/contrib/altq/altq/altq_fairq.h b/sys/contrib/altq/altq/altq_fairq.h
new file mode 100644
index 0000000..7ff6913
--- /dev/null
+++ b/sys/contrib/altq/altq/altq_fairq.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
+ * 
+ * This code is derived from software contributed to The DragonFly Project
+ * by Matthew Dillon <dillon@backplane.com>
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name of The DragonFly Project nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific, prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * 
+ * $DragonFly: src/sys/net/altq/altq_fairq.h,v 1.1 2008/04/06 18:58:15 dillon Exp $
+ * $FreeBSD$
+ */
+
+#ifndef _ALTQ_ALTQ_FAIRQ_H_
+#define	_ALTQ_ALTQ_FAIRQ_H_
+
+#include <altq/altq.h>
+#include <altq/altq_classq.h>
+#include <altq/altq_red.h>
+#include <altq/altq_rio.h>
+#include <altq/altq_rmclass.h>
+
+#define	FAIRQ_MAX_BUCKETS	2048	/* maximum number of sorting buckets */
+#define	FAIRQ_MAXPRI		RM_MAXPRIO
+#define FAIRQ_BITMAP_WIDTH	(sizeof(fairq_bitmap_t)*8)
+#define FAIRQ_BITMAP_MASK	(FAIRQ_BITMAP_WIDTH - 1)
+
+/* fairq class flags */
+#define	FARF_RED		0x0001	/* use RED */
+#define	FARF_ECN		0x0002  /* use RED/ECN */
+#define	FARF_RIO		0x0004  /* use RIO */
+#define	FARF_CLEARDSCP		0x0010  /* clear diffserv codepoint */
+#define	FARF_DEFAULTCLASS	0x1000	/* default class */
+
+#define FARF_HAS_PACKETS	0x2000	/* might have queued packets */
+
+#define FARF_USERFLAGS		(FARF_RED|FARF_ECN|FARF_RIO|FARF_CLEARDSCP| \
+				 FARF_DEFAULTCLASS)
+
+/* special class handles */
+#define	FAIRQ_NULLCLASS_HANDLE	0
+
+typedef u_int	fairq_bitmap_t;
+
+struct fairq_classstats {
+	uint32_t		class_handle;
+
+	u_int			qlength;
+	u_int			qlimit;
+	struct pktcntr		xmit_cnt;  /* transmitted packet counter */
+	struct pktcntr		drop_cnt;  /* dropped packet counter */
+
+	/* red and rio related info */
+	int			qtype;
+	struct redstats		red[3];	/* rio has 3 red stats */
+};
+
+#ifdef _KERNEL
+
+typedef struct fairq_bucket {
+	struct fairq_bucket *next;	/* circular list */
+	struct fairq_bucket *prev;	/* circular list */
+	class_queue_t	queue;		/* the actual queue */
+	uint64_t	bw_bytes;	/* statistics used to calculate bw */
+	uint64_t	bw_delta;	/* statistics used to calculate bw */
+	uint64_t	last_time;
+	int		in_use;
+} fairq_bucket_t;
+
+struct fairq_class {
+	uint32_t	cl_handle;	/* class handle */
+	u_int		cl_nbuckets;	/* (power of 2) */
+	u_int		cl_nbucket_mask; /* bucket mask */
+	fairq_bucket_t	*cl_buckets;
+	fairq_bucket_t	*cl_head;	/* head of circular bucket list */
+	fairq_bucket_t	*cl_polled;
+	struct red	*cl_red;	/* RED state */
+	u_int		cl_hogs_m1;
+	u_int		cl_lssc_m1;
+	u_int		cl_bandwidth;
+	uint64_t	cl_bw_bytes;
+	uint64_t	cl_bw_delta;
+	uint64_t	cl_last_time;
+	int		cl_qtype;	/* rollup */
+	int		cl_qlimit;
+	int		cl_pri;		/* priority */
+	int		cl_flags;	/* class flags */
+	struct fairq_if	*cl_pif;	/* back pointer to pif */
+	struct altq_pktattr *cl_pktattr; /* saved header used by ECN */
+
+	/* round robin index */
+
+	/* statistics */
+	struct pktcntr  cl_xmitcnt;	/* transmitted packet counter */
+	struct pktcntr  cl_dropcnt;	/* dropped packet counter */
+};
+
+/*
+ * fairq interface state
+ */
+struct fairq_if {
+	struct fairq_if		*pif_next;	/* interface state list */
+	struct ifaltq		*pif_ifq;	/* backpointer to ifaltq */
+	u_int			pif_bandwidth;	/* link bandwidth in bps */
+	int			pif_maxpri;	/* max priority in use */
+	struct fairq_class	*pif_poll_cache;/* cached poll */
+	struct fairq_class	*pif_default;	/* default class */
+	struct fairq_class	*pif_classes[FAIRQ_MAXPRI]; /* classes */
+};
+
+#endif /* _KERNEL */
+
+#endif /* _ALTQ_ALTQ_FAIRQ_H_ */
diff --git a/sys/contrib/altq/altq/altq_subr.c b/sys/contrib/altq/altq/altq_subr.c
index 16b796a..d59751a 100644
--- a/sys/contrib/altq/altq/altq_subr.c
+++ b/sys/contrib/altq/altq/altq_subr.c
@@ -537,6 +537,11 @@ altq_pfattach(struct pf_altq *a)
 		error = hfsc_pfattach(a);
 		break;
 #endif
+#ifdef ALTQ_FAIRQ
+	case ALTQT_FAIRQ:
+		error = fairq_pfattach(a);
+		break;
+#endif
 	default:
 		error = ENXIO;
 	}
@@ -612,6 +617,11 @@ altq_add(struct pf_altq *a)
 		error = hfsc_add_altq(a);
 		break;
 #endif
+#ifdef ALTQ_FAIRQ
+        case ALTQT_FAIRQ:
+                error = fairq_add_altq(a);
+                break;
+#endif
 	default:
 		error = ENXIO;
 	}
@@ -648,6 +658,11 @@ altq_remove(struct pf_altq *a)
 		error = hfsc_remove_altq(a);
 		break;
 #endif
+#ifdef ALTQ_FAIRQ
+        case ALTQT_FAIRQ:
+                error = fairq_remove_altq(a);
+                break;
+#endif
 	default:
 		error = ENXIO;
 	}
@@ -681,6 +696,11 @@ altq_add_queue(struct pf_altq *a)
 		error = hfsc_add_queue(a);
 		break;
 #endif
+#ifdef ALTQ_FAIRQ
+        case ALTQT_FAIRQ:
+                error = fairq_add_queue(a);
+                break;
+#endif
 	default:
 		error = ENXIO;
 	}
@@ -714,6 +734,11 @@ altq_remove_queue(struct pf_altq *a)
 		error = hfsc_remove_queue(a);
 		break;
 #endif
+#ifdef ALTQ_FAIRQ
+        case ALTQT_FAIRQ:
+                error = fairq_remove_queue(a);
+                break;
+#endif
 	default:
 		error = ENXIO;
 	}
@@ -747,6 +772,11 @@ altq_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
 		error = hfsc_getqstats(a, ubuf, nbytes);
 		break;
 #endif
+#ifdef ALTQ_FAIRQ
+        case ALTQT_FAIRQ:
+                error = fairq_getqstats(a, ubuf, nbytes);
+                break;
+#endif
 	default:
 		error = ENXIO;
 	}
diff --git a/sys/contrib/altq/altq/altq_var.h b/sys/contrib/altq/altq/altq_var.h
index 956ee16..eb603ea 100644
--- a/sys/contrib/altq/altq/altq_var.h
+++ b/sys/contrib/altq/altq/altq_var.h
@@ -257,5 +257,12 @@ int	hfsc_add_queue(struct pf_altq *);
 int	hfsc_remove_queue(struct pf_altq *);
 int	hfsc_getqstats(struct pf_altq *, void *, int *);
 
+int	fairq_pfattach(struct pf_altq *);
+int	fairq_add_altq(struct pf_altq *);
+int	fairq_remove_altq(struct pf_altq *);
+int	fairq_add_queue(struct pf_altq *);
+int	fairq_remove_queue(struct pf_altq *);
+int	fairq_getqstats(struct pf_altq *, void *, int *);
+
 #endif /* _KERNEL */
 #endif /* _ALTQ_ALTQ_VAR_H_ */