/*      $KAME: altq_cbq.c,v 1.20 2004/04/17 10:54:48 kjc Exp $  */
/*      $DragonFly: src/sys/net/altq/altq_cbq.c,v 1.7 2008/05/14 11:59:23 sephe Exp $ */

/*
 * Copyright (c) Sun Microsystems, Inc. 1993-1998 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.
 *
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the SMCC Technology
 *      Development Group at Sun Microsystems, Inc.
 *
 * 4. The name of the Sun Microsystems, Inc nor may not be used to endorse or
 *      promote products derived from this software without specific prior
 *      written permission.
 *
 * SUN MICROSYSTEMS DOES NOT CLAIM MERCHANTABILITY OF THIS SOFTWARE OR THE
 * SUITABILITY OF THIS SOFTWARE FOR ANY PARTICULAR PURPOSE.  The software is
 * provided "as is" without express or implied warranty of any kind.
 *
 * These notices must be retained in any copies of any part of this software.
 */

#include "opt_altq.h"
#include "opt_inet.h"
#include "opt_inet6.h"

#ifdef ALTQ_CBQ /* cbq is enabled by ALTQ_CBQ option in opt_altq.h */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/callout.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/thread.h>

#include <net/if.h>
#include <net/ifq_var.h>
#include <net/netmsg2.h>
#include <net/netisr2.h>
#include <netinet/in.h>

#include <net/pf/pfvar.h>
#include <net/altq/altq.h>
#include <net/altq/altq_cbq.h>

#include <sys/thread2.h>

#define CBQ_SUBQ_INDEX          ALTQ_SUBQ_INDEX_DEFAULT
#define CBQ_LOCK(ifq) \
    ALTQ_SQ_LOCK(&(ifq)->altq_subq[CBQ_SUBQ_INDEX])
#define CBQ_UNLOCK(ifq) \
    ALTQ_SQ_UNLOCK(&(ifq)->altq_subq[CBQ_SUBQ_INDEX])
#define CBQ_ASSERT_LOCKED(ifq) \
    ALTQ_SQ_ASSERT_LOCKED(&(ifq)->altq_subq[CBQ_SUBQ_INDEX])

/*
 * Forward Declarations.
 */
static int               cbq_class_destroy(cbq_state_t *, struct rm_class *);
static struct rm_class  *clh_to_clp(cbq_state_t *, uint32_t);
static int               cbq_clear_interface(cbq_state_t *);
static int               cbq_request(struct ifaltq_subque *, int, void *);
static int               cbq_enqueue(struct ifaltq_subque *, struct mbuf *,
                             struct altq_pktattr *);
static struct mbuf      *cbq_dequeue(struct ifaltq_subque *, int);
static void              cbqrestart(struct ifaltq *);
static void              get_class_stats(class_stats_t *, struct rm_class *);
static void              cbq_purge(cbq_state_t *);

/*
 * int
 * cbq_class_destroy(cbq_mod_state_t *, struct rm_class *) - This
 *      function destroys a given traffic class.  Before destroying
 *      the class, all traffic for that class is released.
 */
static int
cbq_class_destroy(cbq_state_t *cbqp, struct rm_class *cl)
{
        int     i;

        /* delete the class */
        rmc_delete_class(&cbqp->ifnp, cl);

        /*
         * free the class handle
         */
        for (i = 0; i < CBQ_MAX_CLASSES; i++)
                if (cbqp->cbq_class_tbl[i] == cl)
                        cbqp->cbq_class_tbl[i] = NULL;

        if (cl == cbqp->ifnp.root_)
                cbqp->ifnp.root_ = NULL;
        if (cl == cbqp->ifnp.default_)
                cbqp->ifnp.default_ = NULL;
        return (0);
}

/* convert class handle to class pointer */
static struct rm_class *
clh_to_clp(cbq_state_t *cbqp, uint32_t chandle)
{
        int i;
        struct rm_class *cl;

        if (chandle == 0)
                return (NULL);
        /*
         * first, try optimistically the slot matching the lower bits of
         * the handle.  if it fails, do the linear table search.
         */
        i = chandle % CBQ_MAX_CLASSES;
        if ((cl = cbqp->cbq_class_tbl[i]) != NULL &&
            cl->stats_.handle == chandle)
                return (cl);
        for (i = 0; i < CBQ_MAX_CLASSES; i++)
                if ((cl = cbqp->cbq_class_tbl[i]) != NULL &&
                    cl->stats_.handle == chandle)
                        return (cl);
        return (NULL);
}

static int
cbq_clear_interface(cbq_state_t *cbqp)
{
        int              again, i;
        struct rm_class *cl;

        /* clear out the classes now */
        do {
                again = 0;
                for (i = 0; i < CBQ_MAX_CLASSES; i++) {
                        if ((cl = cbqp->cbq_class_tbl[i]) != NULL) {
                                if (is_a_parent_class(cl))
                                        again++;
                                else {
                                        cbq_class_destroy(cbqp, cl);
                                        cbqp->cbq_class_tbl[i] = NULL;
                                        if (cl == cbqp->ifnp.root_)
                                                cbqp->ifnp.root_ = NULL;
                                        if (cl == cbqp->ifnp.default_)
                                                cbqp->ifnp.default_ = NULL;
                                }
                        }
                }
        } while (again);

        return (0);
}

static int
cbq_request(struct ifaltq_subque *ifsq, int req, void *arg)
{
        struct ifaltq *ifq = ifsq->ifsq_altq;
        cbq_state_t     *cbqp = (cbq_state_t *)ifq->altq_disc;

        crit_enter();
        switch (req) {
        case ALTRQ_PURGE:
                if (ifsq_get_index(ifsq) == CBQ_SUBQ_INDEX) {
                        cbq_purge(cbqp);
                } 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);
}

/* copy the stats info in rm_class to class_states_t */
static void
get_class_stats(class_stats_t *statsp, struct rm_class *cl)
{
        statsp->xmit_cnt        = cl->stats_.xmit_cnt;
        statsp->drop_cnt        = cl->stats_.drop_cnt;
        statsp->over            = cl->stats_.over;
        statsp->borrows         = cl->stats_.borrows;
        statsp->overactions     = cl->stats_.overactions;
        statsp->delays          = cl->stats_.delays;

        statsp->depth           = cl->depth_;
        statsp->priority        = cl->pri_;
        statsp->maxidle         = cl->maxidle_;
        statsp->minidle         = cl->minidle_;
        statsp->offtime         = cl->offtime_;
        statsp->qmax            = qlimit(cl->q_);
        statsp->ns_per_byte     = cl->ns_per_byte_;
        statsp->wrr_allot       = cl->w_allotment_;
        statsp->qcnt            = qlen(cl->q_);
        statsp->avgidle         = cl->avgidle_;

        statsp->qtype           = qtype(cl->q_);
#ifdef ALTQ_RED
        if (q_is_red(cl->q_))
                red_getstats(cl->red_, &statsp->red[0]);
#endif
#ifdef ALTQ_RIO
        if (q_is_rio(cl->q_))
                rio_getstats((rio_t *)cl->red_, &statsp->red[0]);
#endif
}

int
cbq_pfattach(struct pf_altq *a, struct ifaltq *ifq)
{
        return altq_attach(ifq, ALTQT_CBQ, a->altq_disc, ifq_mapsubq_default,
            cbq_enqueue, cbq_dequeue, cbq_request, NULL, NULL);
}

int
cbq_add_altq(struct pf_altq *a)
{
        cbq_state_t     *cbqp;
        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);
        }

        /* allocate and initialize cbq_state_t */
        cbqp = kmalloc(sizeof(*cbqp), M_ALTQ, M_WAITOK | M_ZERO);
        callout_init(&cbqp->cbq_callout);
        cbqp->cbq_qlen = 0;
        cbqp->ifnp.ifq_ = &ifp->if_snd;     /* keep the ifq */
        ifq_purge_all(&ifp->if_snd);

        ifnet_unlock();

        /* keep the state in pf_altq */
        a->altq_disc = cbqp;

        return (0);
}

int
cbq_remove_altq(struct pf_altq *a)
{
        cbq_state_t *cbqp;
        struct ifaltq *ifq;

        if ((cbqp = a->altq_disc) == NULL)
                return (EINVAL);
        a->altq_disc = NULL;

        ifq = cbqp->ifnp.ifq_;
        CBQ_LOCK(ifq);

        cbq_clear_interface(cbqp);

        if (cbqp->ifnp.default_)
                cbq_class_destroy(cbqp, cbqp->ifnp.default_);
        if (cbqp->ifnp.root_)
                cbq_class_destroy(cbqp, cbqp->ifnp.root_);

        CBQ_UNLOCK(ifq);

        /* deallocate cbq_state_t */
        kfree(cbqp, M_ALTQ);

        return (0);
}

static int
cbq_add_queue_locked(struct pf_altq *a, cbq_state_t *cbqp)
{
        struct rm_class *borrow, *parent;
        struct rm_class *cl;
        struct cbq_opts *opts;
        int             i;

        KKASSERT(a->qid != 0);

        /*
         * find a free slot in the class table.  if the slot matching
         * the lower bits of qid is free, use this slot.  otherwise,
         * use the first free slot.
         */
        i = a->qid % CBQ_MAX_CLASSES;
        if (cbqp->cbq_class_tbl[i] != NULL) {
                for (i = 0; i < CBQ_MAX_CLASSES; i++)
                        if (cbqp->cbq_class_tbl[i] == NULL)
                                break;
                if (i == CBQ_MAX_CLASSES)
                        return (EINVAL);
        }

        opts = &a->pq_u.cbq_opts;
        /* check parameters */
        if (a->priority >= CBQ_MAXPRI)
                return (EINVAL);

        /* Get pointers to parent and borrow classes.  */
        parent = clh_to_clp(cbqp, a->parent_qid);
        if (opts->flags & CBQCLF_BORROW)
                borrow = parent;
        else
                borrow = NULL;

        /*
         * A class must borrow from it's parent or it can not
         * borrow at all.  Hence, borrow can be null.
         */
        if (parent == NULL && (opts->flags & CBQCLF_ROOTCLASS) == 0) {
                kprintf("cbq_add_queue: no parent class!\n");
                return (EINVAL);
        }

        if ((borrow != parent)  && (borrow != NULL)) {
                kprintf("cbq_add_class: borrow class != parent\n");
                return (EINVAL);
        }

        /*
         * check parameters
         */
        switch (opts->flags & CBQCLF_CLASSMASK) {
        case CBQCLF_ROOTCLASS:
                if (parent != NULL)
                        return (EINVAL);
                if (cbqp->ifnp.root_)
                        return (EINVAL);
                break;
        case CBQCLF_DEFCLASS:
                if (cbqp->ifnp.default_)
                        return (EINVAL);
                break;
        case 0:
                if (a->qid == 0)
                        return (EINVAL);
                break;
        default:
                /* more than two flags bits set */
                return (EINVAL);
        }

        /*
         * create a class.  if this is a root class, initialize the
         * interface.
         */
        if ((opts->flags & CBQCLF_CLASSMASK) == CBQCLF_ROOTCLASS) {
                rmc_init(cbqp->ifnp.ifq_, &cbqp->ifnp, opts->ns_per_byte,
                    cbqrestart, a->qlimit, RM_MAXQUEUED,
                    opts->maxidle, opts->minidle, opts->offtime,
                    opts->flags);
                cl = cbqp->ifnp.root_;
        } else {
                cl = rmc_newclass(a->priority,
                                  &cbqp->ifnp, opts->ns_per_byte,
                                  rmc_delay_action, a->qlimit, parent, borrow,
                                  opts->maxidle, opts->minidle, opts->offtime,
                                  opts->pktsize, opts->flags);
        }
        if (cl == NULL)
                return (ENOMEM);

        /* return handle to user space. */
        cl->stats_.handle = a->qid;
        cl->stats_.depth = cl->depth_;

        /* save the allocated class */
        cbqp->cbq_class_tbl[i] = cl;

        if ((opts->flags & CBQCLF_CLASSMASK) == CBQCLF_DEFCLASS)
                cbqp->ifnp.default_ = cl;

        return (0);
}

int
cbq_add_queue(struct pf_altq *a)
{
        cbq_state_t *cbqp;
        struct ifaltq *ifq;
        int error;

        if (a->qid == 0)
                return (EINVAL);

        /* XXX not MP safe */
        if ((cbqp = a->altq_disc) == NULL)
                return (EINVAL);
        ifq = cbqp->ifnp.ifq_;

        CBQ_LOCK(ifq);
        error = cbq_add_queue_locked(a, cbqp);
        CBQ_UNLOCK(ifq);

        return error;
}

static int
cbq_remove_queue_locked(struct pf_altq *a, cbq_state_t *cbqp)
{
        struct rm_class *cl;
        int             i;

        if ((cl = clh_to_clp(cbqp, a->qid)) == NULL)
                return (EINVAL);

        /* if we are a parent class, then return an error. */
        if (is_a_parent_class(cl))
                return (EINVAL);

        /* delete the class */
        rmc_delete_class(&cbqp->ifnp, cl);

        /*
         * free the class handle
         */
        for (i = 0; i < CBQ_MAX_CLASSES; i++)
                if (cbqp->cbq_class_tbl[i] == cl) {
                        cbqp->cbq_class_tbl[i] = NULL;
                        if (cl == cbqp->ifnp.root_)
                                cbqp->ifnp.root_ = NULL;
                        if (cl == cbqp->ifnp.default_)
                                cbqp->ifnp.default_ = NULL;
                        break;
                }

        return (0);
}

int
cbq_remove_queue(struct pf_altq *a)
{
        cbq_state_t *cbqp;
        struct ifaltq *ifq;
        int error;

        /* XXX not MP safe */
        if ((cbqp = a->altq_disc) == NULL)
                return (EINVAL);
        ifq = cbqp->ifnp.ifq_;

        CBQ_LOCK(ifq);
        error = cbq_remove_queue_locked(a, cbqp);
        CBQ_UNLOCK(ifq);

        return error;
}

int
cbq_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
{
        cbq_state_t     *cbqp;
        struct rm_class *cl;
        class_stats_t    stats;
        int              error = 0;
        struct ifaltq   *ifq;

        if (*nbytes < sizeof(stats))
                return (EINVAL);

        ifnet_lock();

        /* XXX not MP safe */
        if ((cbqp = altq_lookup(a->ifname, ALTQT_CBQ)) == NULL) {
                ifnet_unlock();
                return (EBADF);
        }
        ifq = cbqp->ifnp.ifq_;

        CBQ_LOCK(ifq);

        if ((cl = clh_to_clp(cbqp, a->qid)) == NULL) {
                CBQ_UNLOCK(ifq);
                ifnet_unlock();
                return (EINVAL);
        }

        get_class_stats(&stats, cl);

        CBQ_UNLOCK(ifq);

        ifnet_unlock();

        if ((error = copyout((caddr_t)&stats, ubuf, sizeof(stats))) != 0)
                return (error);
        *nbytes = sizeof(stats);
        return (0);
}

/*
 * int
 * cbq_enqueue(struct ifaltq_subqueue *ifq, struct mbuf *m,
 *     struct altq_pktattr *pattr)
 *              - Queue data packets.
 *
 *      cbq_enqueue is set to ifp->if_altqenqueue and called by an upper
 *      layer (e.g. ether_output).  cbq_enqueue queues the given packet
 *      to the cbq, then invokes the driver's start routine.
 *
 *      Returns:        0 if the queueing is successful.
 *                      ENOBUFS if a packet dropping occurred as a result of
 *                      the queueing.
 */

static int
cbq_enqueue(struct ifaltq_subque *ifsq, struct mbuf *m,
    struct altq_pktattr *pktattr __unused)
{
        struct ifaltq *ifq = ifsq->ifsq_altq;
        cbq_state_t     *cbqp = (cbq_state_t *)ifq->altq_disc;
        struct rm_class *cl;
        int len;

        if (ifsq_get_index(ifsq) != CBQ_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);
        }

        /* grab class set by classifier */
        M_ASSERTPKTHDR(m);
        if (m->m_pkthdr.fw_flags & PF_MBUF_STRUCTURE)
                cl = clh_to_clp(cbqp, m->m_pkthdr.pf.qid);
        else
                cl = NULL;
        if (cl == NULL) {
                cl = cbqp->ifnp.default_;
                if (cl == NULL) {
                        m_freem(m);
                        return (ENOBUFS);
                }
        }
        crit_enter();
        cl->pktattr_ = NULL;
        len = m_pktlen(m);
        if (rmc_queue_packet(cl, m) != 0) {
                /* drop occurred.  some mbuf was freed in rmc_queue_packet. */
                PKTCNTR_ADD(&cl->stats_.drop_cnt, len);
                crit_exit();
                return (ENOBUFS);
        }

        /* successfully queued. */
        ++cbqp->cbq_qlen;
        ALTQ_SQ_PKTCNT_INC(ifsq);
        crit_exit();
        return (0);
}

static struct mbuf *
cbq_dequeue(struct ifaltq_subque *ifsq, int op)
{
        struct ifaltq *ifq = ifsq->ifsq_altq;
        cbq_state_t     *cbqp = (cbq_state_t *)ifq->altq_disc;
        struct mbuf     *m;

        if (ifsq_get_index(ifsq) != CBQ_SUBQ_INDEX) {
                /*
                 * Race happened, the unrelated subqueue was
                 * picked during the packet scheduler transition.
                 */
                ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
                return NULL;
        }

        crit_enter();
        m = rmc_dequeue_next(&cbqp->ifnp, op);

        if (m && op == ALTDQ_REMOVE) {
                --cbqp->cbq_qlen;  /* decrement # of packets in cbq */
                ALTQ_SQ_PKTCNT_DEC(ifsq);

                /* Update the class. */
                rmc_update_class_util(&cbqp->ifnp);
        }
        crit_exit();
        return (m);
}

/*
 * void
 * cbqrestart(queue_t *) - Restart sending of data.
 * called from rmc_restart in a critical section via timeout after waking up
 * a suspended class.
 *      Returns:        NONE
 */

static void
cbqrestart(struct ifaltq *ifq)
{
        cbq_state_t     *cbqp;

        CBQ_ASSERT_LOCKED(ifq);

        if (!ifq_is_enabled(ifq))
                /* cbq must have been detached */
                return;

        if ((cbqp = (cbq_state_t *)ifq->altq_disc) == NULL)
                /* should not happen */
                return;

        if (cbqp->cbq_qlen > 0) {
                struct ifnet *ifp = ifq->altq_ifp;
                struct ifaltq_subque *ifsq = &ifq->altq_subq[CBQ_SUBQ_INDEX];

                /* Release the altq lock to avoid deadlock */
                CBQ_UNLOCK(ifq);

                ifsq_serialize_hw(ifsq);
                if (ifp->if_start && !ifsq_is_oactive(ifsq))
                        (*ifp->if_start)(ifp, ifsq);
                ifsq_deserialize_hw(ifsq);

                CBQ_LOCK(ifq);
        }
}

static void
cbq_purge(cbq_state_t *cbqp)
{
        struct rm_class *cl;
        int i;
        for (i = 0; i < CBQ_MAX_CLASSES; i++) {
                if ((cl = cbqp->cbq_class_tbl[i]) != NULL)
                        rmc_dropall(cl);
        }
        if (ifq_is_enabled(cbqp->ifnp.ifq_))
                ALTQ_SQ_CNTR_RESET(&cbqp->ifnp.ifq_->altq_subq[CBQ_SUBQ_INDEX]);
}

#endif /* ALTQ_CBQ */