text: /*	$KAME: altq_priq.c,v 1.12 2004/04/17 10:54:48 kjc Exp $	*/
  /*	$DragonFly: src/sys/net/altq/altq_priq.c,v 1.9 2008/05/14 11:59:23 sephe Exp $ */
  
  /*
   * 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.
   */
  /*
   * priority queue
   */
  
  #include "opt_altq.h"
  #include "opt_inet.h"
  #include "opt_inet6.h"
  
  #ifdef ALTQ_PRIQ  /* priq is enabled by ALTQ_PRIQ option in opt_altq.h */
  
  #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 <sys/thread.h>
  
  #include <net/if.h>
  #include <net/ifq_var.h>
  #include <netinet/in.h>
  
  #include <net/pf/pfvar.h>
  #include <net/altq/altq.h>
  #include <net/altq/altq_priq.h>
  
  #include <sys/thread2.h>
  
  #define PRIQ_SUBQ_INDEX		ALTQ_SUBQ_INDEX_DEFAULT
  #define PRIQ_LOCK(ifq) \
      ALTQ_SQ_LOCK(&(ifq)->altq_subq[PRIQ_SUBQ_INDEX])
  #define PRIQ_UNLOCK(ifq) \
      ALTQ_SQ_UNLOCK(&(ifq)->altq_subq[PRIQ_SUBQ_INDEX])
  
  /*
   * function prototypes
   */
  static int	priq_clear_interface(struct priq_if *);
  static int	priq_request(struct ifaltq_subque *, int, void *);
  static void	priq_purge(struct priq_if *);
  static struct priq_class *priq_class_create(struct priq_if *, int, int, int, int);
  static int	priq_class_destroy(struct priq_class *);
  static int	priq_enqueue(struct ifaltq_subque *, struct mbuf *,
  		    struct altq_pktattr *);
  static struct mbuf *priq_dequeue(struct ifaltq_subque *, int);
  
  static int	priq_addq(struct priq_class *, struct mbuf *);
  static struct mbuf *priq_getq(struct priq_class *);
  static struct mbuf *priq_pollq(struct priq_class *);
  static void	priq_purgeq(struct priq_class *);
  
  static void	get_class_stats(struct priq_classstats *, struct priq_class *);
  static struct priq_class *clh_to_clp(struct priq_if *, uint32_t);
  
  int
  priq_pfattach(struct pf_altq *a, struct ifaltq *ifq)
  {
  	return altq_attach(ifq, ALTQT_PRIQ, a->altq_disc, ifq_mapsubq_default,
  	    priq_enqueue, priq_dequeue, priq_request, NULL, NULL);
  }
  
  int
  priq_add_altq(struct pf_altq *a)
  {
  	struct priq_if *pif;
  	struct ifnet *ifp;
  
  	ifnet_lock();
  
  	if ((ifp = ifunit(a->ifname)) == NULL) {
  		ifnet_unlock();
  		return (EINVAL);
  	}
  	if (!ifq_is_ready(&ifp->if_snd)) {
  		ifnet_unlock();
  		return (ENODEV);
  	}
  
  	pif = kmalloc(sizeof(*pif), M_ALTQ, M_WAITOK | M_ZERO);
  	pif->pif_bandwidth = a->ifbandwidth;
  	pif->pif_maxpri = -1;
  	pif->pif_ifq = &ifp->if_snd;
  	ifq_purge_all(&ifp->if_snd);
  
  	ifnet_unlock();
  
  	/* keep the state in pf_altq */
  	a->altq_disc = pif;
  
  	return (0);
  }
  
  int
  priq_remove_altq(struct pf_altq *a)
  {
  	struct priq_if *pif;
  
  	if ((pif = a->altq_disc) == NULL)
  		return (EINVAL);
  	a->altq_disc = NULL;
  
  	priq_clear_interface(pif);
  
  	kfree(pif, M_ALTQ);
  	return (0);
  }
  
  static int
  priq_add_queue_locked(struct pf_altq *a, struct priq_if *pif)
  {
  	struct priq_class *cl;
  
  	KKASSERT(a->priority < PRIQ_MAXPRI);
  	KKASSERT(a->qid != 0);
  
  	if (pif->pif_classes[a->priority] != NULL)
  		return (EBUSY);
  	if (clh_to_clp(pif, a->qid) != NULL)
  		return (EBUSY);
  
  	cl = priq_class_create(pif, a->priority, a->qlimit,
  			       a->pq_u.priq_opts.flags, a->qid);
  	if (cl == NULL)
  		return (ENOMEM);
  
  	return (0);
  }
  
  int
  priq_add_queue(struct pf_altq *a)
  {
  	struct priq_if *pif;
  	struct ifaltq *ifq;
  	int error;
  
  	/* check parameters */
  	if (a->priority >= PRIQ_MAXPRI)
  		return (EINVAL);
  	if (a->qid == 0)
  		return (EINVAL);
  
  	/* XXX not MP safe */
  	if ((pif = a->altq_disc) == NULL)
  		return (EINVAL);
  	ifq = pif->pif_ifq;
  
  	PRIQ_LOCK(ifq);
  	error = priq_add_queue_locked(a, pif);
  	PRIQ_UNLOCK(ifq);
  
  	return error;
  }
  
  static int
  priq_remove_queue_locked(struct pf_altq *a, struct priq_if *pif)
  {
  	struct priq_class *cl;
  
  	if ((cl = clh_to_clp(pif, a->qid)) == NULL)
  		return (EINVAL);
  
  	return (priq_class_destroy(cl));
  }
  
  int
  priq_remove_queue(struct pf_altq *a)
  {
  	struct priq_if *pif;
  	struct ifaltq *ifq;
  	int error;
  
  	/* XXX not MF safe */
  	if ((pif = a->altq_disc) == NULL)
  		return (EINVAL);
  	ifq = pif->pif_ifq;
  
  	PRIQ_LOCK(ifq);
  	error = priq_remove_queue_locked(a, pif);
  	PRIQ_UNLOCK(ifq);
  
  	return error;
  }
  
  int
  priq_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
  {
  	struct priq_if *pif;
  	struct priq_class *cl;
  	struct priq_classstats stats;
  	struct ifaltq *ifq;
  	int error = 0;
  
  	if (*nbytes < sizeof(stats))
  		return (EINVAL);
  
  	ifnet_lock();
  
  	/* XXX not MP safe */
  	if ((pif = altq_lookup(a->ifname, ALTQT_PRIQ)) == NULL) {
  		ifnet_unlock();
  		return (EBADF);
  	}
  	ifq = pif->pif_ifq;
  
  	PRIQ_LOCK(ifq);
  
  	if ((cl = clh_to_clp(pif, a->qid)) == NULL) {
  		PRIQ_UNLOCK(ifq);
  		ifnet_unlock();
  		return (EINVAL);
  	}
  
  	get_class_stats(&stats, cl);
  
  	PRIQ_UNLOCK(ifq);
  
  	ifnet_unlock();
  
  	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
  priq_clear_interface(struct priq_if *pif)
  {
  	struct priq_class *cl;
  	int pri;
  
  	/* clear out the classes */
  	for (pri = 0; pri <= pif->pif_maxpri; pri++) {
  		if ((cl = pif->pif_classes[pri]) != NULL)
  			priq_class_destroy(cl);
  	}
  
  	return (0);
  }
  
  static int
  priq_request(struct ifaltq_subque *ifsq, int req, void *arg)
  {
  	struct ifaltq *ifq = ifsq->ifsq_altq;
  	struct priq_if *pif = (struct priq_if *)ifq->altq_disc;
  
  	crit_enter();
  	switch (req) {
  	case ALTRQ_PURGE:
  		if (ifsq_get_index(ifsq) == PRIQ_SUBQ_INDEX) {
  			priq_purge(pif);
  		} else {
  			/*
  			 * Race happened, the unrelated subqueue was
  			 * picked during the packet scheduler transition.
  			 */
  			ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
  		}
  		break;
  	}
  	crit_exit();
  	return (0);
  }
  
  /* discard all the queued packets on the interface */
  static void
  priq_purge(struct priq_if *pif)
  {
  	struct priq_class *cl;
  	int pri;
  
  	for (pri = 0; pri <= pif->pif_maxpri; pri++) {
  		if ((cl = pif->pif_classes[pri]) != NULL && !qempty(cl->cl_q))
  			priq_purgeq(cl);
  	}
  	if (ifq_is_enabled(pif->pif_ifq))
  		ALTQ_SQ_CNTR_RESET(&pif->pif_ifq->altq_subq[PRIQ_SUBQ_INDEX]);
  }
  
  static struct priq_class *
  priq_class_create(struct priq_if *pif, int pri, int qlimit, int flags, int qid)
  {
  	struct priq_class *cl;
  
  #ifndef ALTQ_RED
  	if (flags & PRCF_RED) {
  #ifdef ALTQ_DEBUG
  		kprintf("priq_class_create: RED not configured for PRIQ!\n");
  #endif
  		return (NULL);
  	}
  #endif
  
  	if ((cl = pif->pif_classes[pri]) != NULL) {
  		/* modify the class instead of creating a new one */
  		crit_enter();
  		if (!qempty(cl->cl_q))
  			priq_purgeq(cl);
  		crit_exit();
  #ifdef ALTQ_RIO
  		if (q_is_rio(cl->cl_q))
  			rio_destroy((rio_t *)cl->cl_red);
  #endif
  #ifdef ALTQ_RED
  		if (q_is_red(cl->cl_q))
  			red_destroy(cl->cl_red);
  #endif
  	} else {
  		cl = kmalloc(sizeof(*cl), M_ALTQ, M_WAITOK | M_ZERO);
  		cl->cl_q = kmalloc(sizeof(*cl->cl_q), M_ALTQ, M_WAITOK | M_ZERO);
  	}
  
  	pif->pif_classes[pri] = cl;
  	if (flags & PRCF_DEFAULTCLASS)
  		pif->pif_default = cl;
  	if (qlimit == 0)
  		qlimit = 50;  /* use default */
  	qlimit(cl->cl_q) = qlimit;
  	qtype(cl->cl_q) = Q_DROPTAIL;
  	qlen(cl->cl_q) = 0;
  	cl->cl_flags = flags;
  	cl->cl_pri = pri;
  	if (pri > pif->pif_maxpri)
  		pif->pif_maxpri = pri;
  	cl->cl_pif = pif;
  	cl->cl_handle = qid;
  
  #ifdef ALTQ_RED
  	if (flags & (PRCF_RED|PRCF_RIO)) {
  		int red_flags, red_pkttime;
  
  		red_flags = 0;
  		if (flags & PRCF_ECN)
  			red_flags |= REDF_ECN;
  #ifdef ALTQ_RIO
  		if (flags & PRCF_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 & PRCF_RIO) {
  			cl->cl_red = (red_t *)rio_alloc(0, NULL,
  						red_flags, red_pkttime);
  			if (cl->cl_red != NULL)
  				qtype(cl->cl_q) = Q_RIO;
  		} else
  #endif
  		if (flags & PRCF_RED) {
  			cl->cl_red = red_alloc(0, 0,
  			    qlimit(cl->cl_q) * 10/100,
  			    qlimit(cl->cl_q) * 30/100,
  			    red_flags, red_pkttime);
  			if (cl->cl_red != NULL)
  				qtype(cl->cl_q) = Q_RED;
  		}
  	}
  #endif /* ALTQ_RED */
  
  	return (cl);
  }
  
  static int
  priq_class_destroy(struct priq_class *cl)
  {
  	struct priq_if *pif;
  	int pri;
  
  	crit_enter();
  
  	if (!qempty(cl->cl_q))
  		priq_purgeq(cl);
  
  	pif = cl->cl_pif;
  	pif->pif_classes[cl->cl_pri] = 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;
  	}
  	crit_exit();
  
  	if (cl->cl_red != NULL) {
  #ifdef ALTQ_RIO
  		if (q_is_rio(cl->cl_q))
  			rio_destroy((rio_t *)cl->cl_red);
  #endif
  #ifdef ALTQ_RED
  		if (q_is_red(cl->cl_q))
  			red_destroy(cl->cl_red);
  #endif
  	}
  	kfree(cl->cl_q, M_ALTQ);
  	kfree(cl, M_ALTQ);
  	return (0);
  }
  
  /*
   * priq_enqueue is an enqueue function to be registered to
   * (*ifsq_enqueue) in struct ifaltq_subque.
   */
  static int
  priq_enqueue(struct ifaltq_subque *ifsq, struct mbuf *m,
      struct altq_pktattr *pktattr)
  {
  	struct ifaltq *ifq = ifsq->ifsq_altq;
  	struct priq_if *pif = (struct priq_if *)ifq->altq_disc;
  	struct priq_class *cl;
  	int error;
  	int len;
  
  	if (ifsq_get_index(ifsq) != PRIQ_SUBQ_INDEX) {
  		/*
  		 * Race happened, the unrelated subqueue was
  		 * picked during the packet scheduler transition.
  		 */
  		ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
  		m_freem(m);
  		return ENOBUFS;
  	}
  
  	crit_enter();
  
  	/* grab class set by classifier */
  	M_ASSERTPKTHDR(m);
  	if (m->m_pkthdr.fw_flags & PF_MBUF_STRUCTURE)
  		cl = clh_to_clp(pif, m->m_pkthdr.pf.qid);
  	else
  		cl = NULL;
  	if (cl == NULL) {
  		cl = pif->pif_default;
  		if (cl == NULL) {
  			m_freem(m);
  			error = ENOBUFS;
  			goto done;
  		}
  	}
  	cl->cl_pktattr = NULL;
  	len = m_pktlen(m);
  	if (priq_addq(cl, m) != 0) {
  		/* drop occurred.  mbuf was freed in priq_addq. */
  		PKTCNTR_ADD(&cl->cl_dropcnt, len);
  		error = ENOBUFS;
  		goto done;
  	}
  	ALTQ_SQ_PKTCNT_INC(ifsq);
  	error = 0;
  done:
  	crit_exit();
  	return (error);
  }
  
  /*
   * priq_dequeue is a dequeue function to be registered to
   * (*ifsq_dequeue) in struct ifaltq_subque.
   *
   * note: ALTDQ_POLL returns the next packet without removing the packet
   *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
   */
  static struct mbuf *
  priq_dequeue(struct ifaltq_subque *ifsq, int op)
  {
  	struct ifaltq *ifq = ifsq->ifsq_altq;
  	struct priq_if *pif = (struct priq_if *)ifq->altq_disc;
  	struct priq_class *cl;
  	struct mbuf *m;
  	int pri;
  
  	if (ifsq_get_index(ifsq) != PRIQ_SUBQ_INDEX) {
  		/*
  		 * Race happened, the unrelated subqueue was
  		 * picked during the packet scheduler transition.
  		 */
  		ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
  		return NULL;
  	}
  
  	if (ifsq_is_empty(ifsq)) {
  		/* no packet in the queue */
  		return (NULL);
  	}
  
  	crit_enter();
  	m = NULL;
  	for (pri = pif->pif_maxpri;  pri >= 0; pri--) {
  		if ((cl = pif->pif_classes[pri]) != NULL && !qempty(cl->cl_q)) {
  			if (op == ALTDQ_POLL) {
  				m = priq_pollq(cl);
  				break;
  			}
  
  			m = priq_getq(cl);
  			if (m != NULL) {
  				ALTQ_SQ_PKTCNT_DEC(ifsq);
  				if (qempty(cl->cl_q))
  					cl->cl_period++;
  				PKTCNTR_ADD(&cl->cl_xmitcnt, m_pktlen(m));
  			}
  			break;
  		}
  	}
  	crit_exit();
  	return (m);
  }
  
  static int
  priq_addq(struct priq_class *cl, struct mbuf *m)
  {
  #ifdef ALTQ_RIO
  	if (q_is_rio(cl->cl_q))
  		return rio_addq((rio_t *)cl->cl_red, cl->cl_q, m,
  				cl->cl_pktattr);
  #endif
  #ifdef ALTQ_RED
  	if (q_is_red(cl->cl_q))
  		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
  #endif
  	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
  		m_freem(m);
  		return (-1);
  	}
  
  	if (cl->cl_flags & PRCF_CLEARDSCP)
  		write_dsfield(m, cl->cl_pktattr, 0);
  
  	_addq(cl->cl_q, m);
  
  	return (0);
  }
  
  static struct mbuf *
  priq_getq(struct priq_class *cl)
  {
  #ifdef ALTQ_RIO
  	if (q_is_rio(cl->cl_q))
  		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
  #endif
  #ifdef ALTQ_RED
  	if (q_is_red(cl->cl_q))
  		return red_getq(cl->cl_red, cl->cl_q);
  #endif
  	return _getq(cl->cl_q);
  }
  
  static struct mbuf *
  priq_pollq(struct priq_class *cl)
  {
  	return qhead(cl->cl_q);
  }
  
  static void
  priq_purgeq(struct priq_class *cl)
  {
  	struct mbuf *m;
  
  	if (qempty(cl->cl_q))
  		return;
  
  	while ((m = _getq(cl->cl_q)) != NULL) {
  		PKTCNTR_ADD(&cl->cl_dropcnt, m_pktlen(m));
  		m_freem(m);
  	}
  	KKASSERT(qlen(cl->cl_q) == 0);
  }
  
  static void
  get_class_stats(struct priq_classstats *sp, struct priq_class *cl)
  {
  	sp->class_handle = cl->cl_handle;
  	sp->qlength = qlen(cl->cl_q);
  	sp->qlimit = qlimit(cl->cl_q);
  	sp->period = cl->cl_period;
  	sp->xmitcnt = cl->cl_xmitcnt;
  	sp->dropcnt = cl->cl_dropcnt;
  
  	sp->qtype = qtype(cl->cl_q);
  #ifdef ALTQ_RED
  	if (q_is_red(cl->cl_q))
  		red_getstats(cl->cl_red, &sp->red[0]);
  #endif
  #ifdef ALTQ_RIO
  	if (q_is_rio(cl->cl_q))
  		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
  #endif
  }
  
  /* convert a class handle to the corresponding class pointer */
  static struct priq_class *
  clh_to_clp(struct priq_if *pif, uint32_t chandle)
  {
  	struct priq_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_PRIQ */
  