io/net80211/net80211_ht.c

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 2007 Sam Leffler, Errno Consulting
 * 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 THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * IEEE 802.11n protocol support.
 */
#include <sys/mac_provider.h>
#include <sys/strsun.h>
#include <sys/byteorder.h>

#include "net80211_impl.h"

/* define here, used throughout file */
#define MS(_v, _f)  (((_v) & _f) >> _f##_S)
#define SM(_v, _f)  (((_v) << _f##_S) & _f)

/* need max array size */
/* NB: these are for HT20 w/ long GI */
const int ieee80211_htrates[16] = {
    13,     /* IFM_IEEE80211_MCS0 */
    26,     /* IFM_IEEE80211_MCS1 */
    39,     /* IFM_IEEE80211_MCS2 */
    52,     /* IFM_IEEE80211_MCS3 */
    78,     /* IFM_IEEE80211_MCS4 */
    104,        /* IFM_IEEE80211_MCS5 */
    117,        /* IFM_IEEE80211_MCS6 */
    130,        /* IFM_IEEE80211_MCS7 */
    26,     /* IFM_IEEE80211_MCS8 */
    52,     /* IFM_IEEE80211_MCS9 */
    78,     /* IFM_IEEE80211_MCS10 */
    104,        /* IFM_IEEE80211_MCS11 */
    156,        /* IFM_IEEE80211_MCS12 */
    208,        /* IFM_IEEE80211_MCS13 */
    234,        /* IFM_IEEE80211_MCS14 */
    260,        /* IFM_IEEE80211_MCS15 */
};

struct ieee80211_htrateset ieee80211_rateset_11n =
    { 16, {
    /* MCS: 6.5   13 19.5   26   39  52 58.5  65  13  26 */
        0,   1,   2,   3,   4,  5,   6,  7,  8,  9,
    /* 39   52   78  104  117, 130 */
        10,  11,  12,  13,  14,  15 }
    };

#define IEEE80211_AMPDU_AGE

#define IEEE80211_AGGR_TIMEOUT  250     /* msecs */
#define IEEE80211_AGGR_MINRETRY (10 * hz)   /* ticks */
#define IEEE80211_AGGR_MAXTRIES 3

/*
 * Receive processing.
 */

/*
 * Decap the encapsulated A-MSDU frames and dispatch all but
 * the last for delivery.  The last frame is returned for
 * delivery via the normal path.
 */
#define FF_LLC_SIZE \
    (sizeof (struct ether_header) + sizeof (struct ieee80211_llc))
mblk_t *
ieee80211_decap_amsdu(struct ieee80211_node *in, mblk_t *mp)
{
    struct ieee80211com *ic = in->in_ic;
    struct ether_header *eh;
    struct ieee80211_frame *wh;
    int framelen, hdrspace;
    mblk_t *m0;

    /* all msdu has same ieee80211_frame header */
    wh = (struct ieee80211_frame *)mp->b_rptr;
    hdrspace = ieee80211_hdrspace(ic, wh);
    mp->b_rptr += hdrspace; /* A-MSDU subframe follows */

    for (;;) {
        /*
         * The frame has an 802.3 header followed by an 802.2
         * LLC header.  The encapsulated frame length is in the
         * first header type field;
         */
        if (MBLKL(mp) < FF_LLC_SIZE) {
            ieee80211_err("too short, decap failed\n");
            goto out;
        }
        /*
         * Decap frames, encapsulate to 802.11 frame then deliver.
         * 802.3 header is first (struct ether_header)
         * 802.2 header follows (struct ieee80211_llc)
         * data, msdu = llc + data
         */
        eh = (struct ether_header *)mp->b_rptr;
                        /* 802.2 header follows */
        framelen = ntohs(eh->ether_type);   /* llc + data */
        m0 = allocb(hdrspace + framelen, BPRI_MED);
        if (m0 == NULL) {
            ieee80211_err("decap_msdu(): can't alloc mblk\n");
            goto out;
        }
        (void) memcpy(m0->b_wptr, (uint8_t *)wh, hdrspace);
        m0->b_wptr += hdrspace;
        (void) memcpy(m0->b_wptr,
            mp->b_rptr + sizeof (struct ether_header), framelen);
        m0->b_wptr += framelen;

        ic->ic_stats.is_rx_frags++;
        ic->ic_stats.is_rx_bytes += MBLKL(m0);
        IEEE80211_UNLOCK(ic);
        mac_rx(ic->ic_mach, NULL, m0);  /* deliver to mac */
        IEEE80211_LOCK(ic);

        framelen += sizeof (struct ether_header);
        if (MBLKL(mp) == framelen)  /* last, no padding */
            goto out;
        /*
         * Remove frame contents; each intermediate frame
         * is required to be aligned to a 4-byte boundary.
         */
        mp->b_rptr += roundup(framelen, 4); /* padding */
    }

out:
    freemsg(mp);
    return (NULL);  /* none delivered by caller */
}
#undef FF_LLC_SIZE

/*
 * Start A-MPDU rx/re-order processing for the specified TID.
 */
static void
ampdu_rx_start(struct ieee80211_rx_ampdu *rap, int bufsiz, int start)
{
    (void) memset(rap, 0, sizeof (*rap));
    rap->rxa_wnd = (bufsiz == 0) ? IEEE80211_AGGR_BAWMAX
        : min((uint16_t)bufsiz, IEEE80211_AGGR_BAWMAX);
    rap->rxa_start = (uint16_t)start;
    rap->rxa_flags |= IEEE80211_AGGR_XCHGPEND;
}

/*
 * Purge all frames in the A-MPDU re-order queue.
 */
static void
ampdu_rx_purge(struct ieee80211_rx_ampdu *rap)
{
    mblk_t *m;
    int i;

    for (i = 0; i < rap->rxa_wnd; i++) {
        m = rap->rxa_m[i];
        if (m != NULL) {
            rap->rxa_m[i] = NULL;
            rap->rxa_qbytes -= MBLKL(m);
            freemsg(m);
            if (--rap->rxa_qframes == 0)
                break;
        }
    }
    ASSERT(rap->rxa_qbytes == 0 && rap->rxa_qframes == 0);
}

/*
 * Stop A-MPDU rx processing for the specified TID.
 */
static void
ampdu_rx_stop(struct ieee80211_rx_ampdu *rap)
{
    rap->rxa_flags &= ~IEEE80211_AGGR_XCHGPEND;
    ampdu_rx_purge(rap);
}

/*
 * Dispatch a frame from the A-MPDU reorder queue.  The
 * frame is fed back into ieee80211_input marked with an
 * M_AMPDU flag so it doesn't come back to us (it also
 * permits ieee80211_input to optimize re-processing).
 */
static void
ampdu_dispatch(struct ieee80211_node *in, mblk_t *m)
{
    m->b_flag |= M_AMPDU;   /* bypass normal processing */
    /* NB: rssi and rstamp are ignored w/ M_AMPDU set */
    (void) ieee80211_input(in->in_ic, m, in, 0, 0);
}

/*
 * Dispatch as many frames as possible from the re-order queue.
 * Frames will always be "at the front"; we process all frames
 * up to the first empty slot in the window.  On completion we
 * cleanup state if there are still pending frames in the current
 * BA window.  We assume the frame at slot 0 is already handled
 * by the caller; we always start at slot 1.
 */
static void
ampdu_rx_dispatch(struct ieee80211_rx_ampdu *rap, struct ieee80211_node *in)
{
    mblk_t *m;
    int i;

    /* flush run of frames */
    for (i = 1; i < rap->rxa_wnd; i++) {
        m = rap->rxa_m[i];
        if (m == NULL)
            break;
        rap->rxa_m[i] = NULL;
        rap->rxa_qbytes -= MBLKL(m);
        rap->rxa_qframes--;

        ampdu_dispatch(in, m);
    }
    /*
     * If frames remain, copy the mbuf pointers down so
     * they correspond to the offsets in the new window.
     */
    if (rap->rxa_qframes != 0) {
        int n = rap->rxa_qframes, j;
        for (j = i+1; j < rap->rxa_wnd; j++) {
            if (rap->rxa_m[j] != NULL) {
                rap->rxa_m[j-i] = rap->rxa_m[j];
                rap->rxa_m[j] = NULL;
                if (--n == 0)
                    break;
            }
        }
        ASSERT(n == 0);
    }
    /*
     * Adjust the start of the BA window to
     * reflect the frames just dispatched.
     */
    rap->rxa_start = IEEE80211_SEQ_ADD(rap->rxa_start, i);
}

#ifdef IEEE80211_AMPDU_AGE
/*
 * Dispatch all frames in the A-MPDU re-order queue.
 */
static void
ampdu_rx_flush(struct ieee80211_node *in, struct ieee80211_rx_ampdu *rap)
{
    mblk_t *m;
    int i;

    ieee80211_dbg(IEEE80211_MSG_HT,
        "ampdu_rx_flush(%d)\n",
        rap->rxa_wnd);

    for (i = 0; i < rap->rxa_wnd; i++) {
        m = rap->rxa_m[i];
        if (m == NULL)
            continue;
        rap->rxa_m[i] = NULL;
        rap->rxa_qbytes -= MBLKL(m);
        rap->rxa_qframes--;

        ampdu_dispatch(in, m);
        if (rap->rxa_qframes == 0)
            break;
    }
}
#endif /* IEEE80211_AMPDU_AGE */

/*
 * Dispatch all frames in the A-MPDU re-order queue
 * preceding the specified sequence number.  This logic
 * handles window moves due to a received MSDU or BAR.
 */
static void
ampdu_rx_flush_upto(struct ieee80211_node *in,
    struct ieee80211_rx_ampdu *rap, ieee80211_seq winstart)
{
    mblk_t *m;
    ieee80211_seq seqno;
    int i;

    /*
     * Flush any complete MSDU's with a sequence number lower
     * than winstart.  Gaps may exist.  Note that we may actually
     * dispatch frames past winstart if a run continues; this is
     * an optimization that avoids having to do a separate pass
     * to dispatch frames after moving the BA window start.
     */
    seqno = rap->rxa_start;
    for (i = 0; i < rap->rxa_wnd; i++) {
        m = rap->rxa_m[i];
        if (m != NULL) {
            rap->rxa_m[i] = NULL;
            rap->rxa_qbytes -= MBLKL(m);
            rap->rxa_qframes--;

            ampdu_dispatch(in, m);
        } else {
            if (!IEEE80211_SEQ_BA_BEFORE(seqno, winstart))
                break;
        }
        seqno = IEEE80211_SEQ_INC(seqno);
    }
    /*
     * If frames remain, copy the mbuf pointers down so
     * they correspond to the offsets in the new window.
     */
    if (rap->rxa_qframes != 0) {
        int n = rap->rxa_qframes, j;
        for (j = i+1; j < rap->rxa_wnd; j++) {
            if (rap->rxa_m[j] != NULL) {
                rap->rxa_m[j-i] = rap->rxa_m[j];
                rap->rxa_m[j] = NULL;
                if (--n == 0)
                    break;
            }
        }
        if (n != 0) {
            ieee80211_dbg(IEEE80211_MSG_HT,
                "ampdu_rx_flush_upto(): "
                "lost %d frames, qframes %d off %d "
                "BA win <%d:%d> winstart %d\n",
                n, rap->rxa_qframes, i, rap->rxa_start,
                IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
                winstart);
        }
    }
    /*
     * Move the start of the BA window; we use the
     * sequence number of the last MSDU that was
     * passed up the stack+1 or winstart if stopped on
     * a gap in the reorder buffer.
     */
    rap->rxa_start = seqno;
}

/*
 * Process a received QoS data frame for an HT station.  Handle
 * A-MPDU reordering: if this frame is received out of order
 * and falls within the BA window hold onto it.  Otherwise if
 * this frame completes a run, flush any pending frames.  We
 * return 1 if the frame is consumed.  A 0 is returned if
 * the frame should be processed normally by the caller.
 */
int
ieee80211_ampdu_reorder(struct ieee80211_node *in, mblk_t *m)
{
#define IEEE80211_FC0_QOSDATA \
    (IEEE80211_FC0_TYPE_DATA | IEEE80211_FC0_SUBTYPE_QOS | \
    IEEE80211_FC0_VERSION_0)

#define PROCESS     0   /* caller should process frame */
#define CONSUMED    1   /* frame consumed, caller does nothing */

    struct ieee80211_qosframe *wh;
    struct ieee80211_rx_ampdu *rap;
    ieee80211_seq rxseq;
    uint8_t tid;
    int off;

    ASSERT(in->in_flags & IEEE80211_NODE_HT);

    /* NB: m_len known to be sufficient */
    wh = (struct ieee80211_qosframe *)m->b_rptr;
    ASSERT(wh->i_fc[0] == IEEE80211_FC0_QOSDATA);

    if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS)
        tid = ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0];
    else
        tid = wh->i_qos[0];
    tid &= IEEE80211_QOS_TID;
    rap = &in->in_rx_ampdu[tid];
    if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
        /*
         * No ADDBA request yet, don't touch.
         */
        return (PROCESS);
    }
    rxseq = LE_16(*(uint16_t *)wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
    rap->rxa_nframes++;
again:
    if (rxseq == rap->rxa_start) {
        /*
         * First frame in window.
         */
        if (rap->rxa_qframes != 0) {
            /*
             * Dispatch as many packets as we can.
             */
            ASSERT(rap->rxa_m[0] == NULL);  /* [0] is m */
            ampdu_dispatch(in, m);
            ampdu_rx_dispatch(rap, in);
            ieee80211_dbg(IEEE80211_MSG_HT,
                "ieee80211_ampdu_reorder(%u), CONSUMED ...\n",
                rap->rxa_qframes);
            return (CONSUMED);
        } else {
            /*
             * In order; advance window and notify
             * caller to dispatch directly.
             */
            rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
            ieee80211_dbg(IEEE80211_MSG_HT,
                "ieee80211_ampdu_reorder(%u), PROCESS ...\n",
                rap->rxa_start);
            return (PROCESS);
        }
    }
    ieee80211_dbg(IEEE80211_MSG_HT,
        "ieee80211_ampdu_reorder(%u, %u), out of order ...\n",
        rxseq, rap->rxa_start);
    /*
     * Frame is out of order; store if in the BA window.
     */
    /* calculate offset in BA window */
    off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
    if (off < rap->rxa_wnd) {
#ifdef IEEE80211_AMPDU_AGE
        /*
         * Common case (hopefully): in the BA window.
         * Sec 9.10.7.6 a) (D2.04 p.118 line 47)
         * --
         * Check for frames sitting too long in the reorder queue.
         * This should only ever happen if frames are not delivered
         * without the sender otherwise notifying us (e.g. with a
         * BAR to move the window).  Typically this happens because
         * of vendor bugs that cause the sequence number to jump.
         * When this happens we get a gap in the reorder queue that
         * leaves frame sitting on the queue until they get pushed
         * out due to window moves.  When the vendor does not send
         * BAR this move only happens due to explicit packet sends
         *
         * NB: we only track the time of the oldest frame in the
         * reorder q; this means that if we flush we might push
         * frames that still "new"; if this happens then subsequent
         * frames will result in BA window moves which cost something
         * but is still better than a big throughput dip.
         */
        clock_t ticks;

        ticks = ddi_get_lbolt();
        if (rap->rxa_qframes != 0) {
            /* honor batimeout? */
            if (ticks - rap->rxa_age > drv_usectohz(500*1000)) {
                /*
                 * Too long since we received the first
                 * frame; flush the reorder buffer.
                 */
                if (rap->rxa_qframes != 0) {
                    ampdu_rx_flush(in, rap);
                }
                rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
                return (PROCESS);
            }
        } else {
            /*
             * First frame, start aging timer.
             */
            rap->rxa_age = ticks;
        }
#endif /* IEEE80211_AMPDU_AGE */
        /* save packet */
        if (rap->rxa_m[off] == NULL) {
            rap->rxa_m[off] = m;
            rap->rxa_qframes++;
            rap->rxa_qbytes += MBLKL(m);
        } else {
            ieee80211_dbg(IEEE80211_MSG_INPUT | IEEE80211_MSG_HT,
                "a-mpdu duplicate "
                "seqno %u tid %u BA win <%u:%u>\n",
                rxseq, tid, rap->rxa_start,
                IEEE80211_SEQ_ADD(rap->rxa_start,
                rap->rxa_wnd - 1));
            freemsg(m);
        }
        return (CONSUMED);
    }
    if (off < IEEE80211_SEQ_BA_RANGE) {
        /*
         * Outside the BA window, but within range;
         * flush the reorder q and move the window.
         * Sec 9.10.7.6 b) (D2.04 p.118 line 60)
         */
        ieee80211_dbg(IEEE80211_MSG_HT,
            "move BA win <%u:%u> (%u frames) rxseq %u tid %u\n",
            rap->rxa_start,
            IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd - 1),
            rap->rxa_qframes, rxseq, tid);

        /*
         * The spec says to flush frames up to but not including:
         *  WinStart_B = rxseq - rap->rxa_wnd + 1
         * Then insert the frame or notify the caller to process
         * it immediately.  We can safely do this by just starting
         * over again because we know the frame will now be within
         * the BA window.
         */
        /* NB: rxa_wnd known to be >0 */
        ampdu_rx_flush_upto(in, rap,
            IEEE80211_SEQ_SUB(rxseq, rap->rxa_wnd-1));
        goto again;
    } else {
        /*
         * Outside the BA window and out of range; toss.
         * Sec 9.10.7.6 c) (D2.04 p.119 line 16)
         */
        ieee80211_dbg(IEEE80211_MSG_HT, "MSDU"
            "BA win <%u:%u> (%u frames) rxseq %u tid %u%s\n",
            rap->rxa_start,
            IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
            rap->rxa_qframes, rxseq, tid,
            wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
        freemsg(m);
        return (CONSUMED);
    }

#undef CONSUMED
#undef PROCESS
#undef IEEE80211_FC0_QOSDATA
}

/*
 * Process a BAR ctl frame.  Dispatch all frames up to
 * the sequence number of the frame.  If this frame is
 * out of range it's discarded.
 */
void
ieee80211_recv_bar(struct ieee80211_node *in, mblk_t *m0)
{
    struct ieee80211_frame_bar *wh;
    struct ieee80211_rx_ampdu *rap;
    ieee80211_seq rxseq;
    int tid, off;

    wh = (struct ieee80211_frame_bar *)m0->b_rptr;
    /* check basic BAR */
    tid = MS(LE_16(wh->i_ctl), IEEE80211_BAR_TID);
    rap = &in->in_rx_ampdu[tid];
    if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
        /*
         * No ADDBA request yet, don't touch.
         */
        ieee80211_dbg(IEEE80211_MSG_INPUT | IEEE80211_MSG_HT,
            "BAR no BA stream, tid %u\n", tid);
        return;
    }
    rxseq = LE_16(wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
    if (rxseq == rap->rxa_start)
        return;
    /* calculate offset in BA window */
    off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
    if (off < IEEE80211_SEQ_BA_RANGE) {
        /*
         * Flush the reorder q up to rxseq and move the window.
         * Sec 9.10.7.6 a) (D2.04 p.119 line 22)
         */
        ieee80211_dbg(IEEE80211_MSG_HT,
            "BAR moves BA win <%u:%u> (%u frames) rxseq %u tid %u\n",
            rap->rxa_start,
            IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
            rap->rxa_qframes, rxseq, tid);

        ampdu_rx_flush_upto(in, rap, rxseq);
        if (off >= rap->rxa_wnd) {
            /*
             * BAR specifies a window start to the right of BA
             * window; we must move it explicitly since
             * ampdu_rx_flush_upto will not.
             */
            rap->rxa_start = rxseq;
        }
    } else {
        /*
         * Out of range; toss.
         * Sec 9.10.7.6 b) (D2.04 p.119 line 41)
         */
        ieee80211_dbg(IEEE80211_MSG_HT, "BAR "
            "BA win <%u:%u> (%u frames) rxseq %u tid %u%s\n",
            rap->rxa_start,
            IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
            rap->rxa_qframes, rxseq, tid,
            wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
    }
}

/*
 * Setup HT-specific state in a node.  Called only
 * when HT use is negotiated so we don't do extra
 * work for temporary and/or legacy sta's.
 */
void
ieee80211_ht_node_init(struct ieee80211_node *in, const uint8_t *htcap)
{
    struct ieee80211_tx_ampdu *tap;
    int ac;

    if (in->in_flags & IEEE80211_NODE_HT) {
        /*
         * Clean AMPDU state on re-associate.  This handles the case
         * where a station leaves w/o notifying us and then returns
         * before node is reaped for inactivity.
         */
        ieee80211_ht_node_cleanup(in);
    }
    ieee80211_parse_htcap(in, htcap);
    for (ac = 0; ac < WME_NUM_AC; ac++) {
        tap = &in->in_tx_ampdu[ac];
        tap->txa_ac = (uint8_t)ac;
        /* NB: further initialization deferred */
    }
    in->in_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
}

/*
 * Cleanup HT-specific state in a node.  Called only
 * when HT use has been marked.
 */
void
ieee80211_ht_node_cleanup(struct ieee80211_node *in)
{
    struct ieee80211com *ic = in->in_ic;
    int i;

    ASSERT(in->in_flags & IEEE80211_NODE_HT);

    /* optimize this */
    for (i = 0; i < WME_NUM_AC; i++) {
        struct ieee80211_tx_ampdu *tap = &in->in_tx_ampdu[i];
        if (tap->txa_flags & IEEE80211_AGGR_SETUP) {
            /*
             * Stop BA stream if setup so driver has a chance
             * to reclaim any resources it might have allocated.
             */
            ic->ic_addba_stop(in, &in->in_tx_ampdu[i]);
            /* IEEE80211_TAPQ_DESTROY(tap); */
            /* NB: clearing NAK means we may re-send ADDBA */
            tap->txa_flags &=
                ~(IEEE80211_AGGR_SETUP | IEEE80211_AGGR_NAK);
        }
    }
    for (i = 0; i < WME_NUM_TID; i++)
        ampdu_rx_stop(&in->in_rx_ampdu[i]);

    in->in_htcap = 0;
    in->in_flags &= ~(IEEE80211_NODE_HT | IEEE80211_NODE_HTCOMPAT |
        IEEE80211_NODE_AMPDU);
}

static struct ieee80211_channel *
findhtchan(struct ieee80211com *ic, struct ieee80211_channel *c, int htflags)
{
    return ieee80211_find_channel(ic, c->ich_freq,
        (c->ich_flags &~ IEEE80211_CHAN_HT) | htflags);
}

/*
 * Adjust a channel to be HT/non-HT according to the vap's configuration.
 */
struct ieee80211_channel *
ieee80211_ht_adjust_channel(struct ieee80211com *ic,
    struct ieee80211_channel *chan, int flags)
{
    struct ieee80211_channel *c;

    if (flags & IEEE80211_FEXT_HT) {
        /* promote to HT if possible */
        if (flags & IEEE80211_FEXT_USEHT40) {
            if (!IEEE80211_IS_CHAN_HT40(chan)) {
                /* NB: arbitrarily pick ht40+ over ht40- */
                c = findhtchan(ic, chan, IEEE80211_CHAN_HT40U);
                if (c == NULL)
                    c = findhtchan(ic, chan,
                        IEEE80211_CHAN_HT40D);
                if (c == NULL)
                    c = findhtchan(ic, chan,
                        IEEE80211_CHAN_HT20);
                if (c != NULL)
                    chan = c;
            }
        } else if (!IEEE80211_IS_CHAN_HT20(chan)) {
            c = findhtchan(ic, chan, IEEE80211_CHAN_HT20);
            if (c != NULL)
                chan = c;
        }
    } else if (IEEE80211_IS_CHAN_HT(chan)) {
        /* demote to legacy, HT use is disabled */
        c = ieee80211_find_channel(ic, chan->ich_freq,
            chan->ich_flags &~ IEEE80211_CHAN_HT);
        if (c != NULL)
            chan = c;
    }
    return (chan);
}

/*
 * Setup HT-specific state for a legacy WDS peer.
 */
void
ieee80211_ht_wds_init(struct ieee80211_node *in)
{
    struct ieee80211com *ic = in->in_ic;
    struct ieee80211_tx_ampdu *tap;
    int ac;

    ASSERT(ic->ic_flags_ext & IEEE80211_FEXT_HT);

    /* check scan cache in case peer has an ap and we have info */
    /*
     * If setup with a legacy channel; locate an HT channel.
     * Otherwise if the inherited channel (from a companion
     * AP) is suitable use it so we use the same location
     * for the extension channel).
     */
    in->in_chan = ieee80211_ht_adjust_channel(ic, in->in_chan,
        ic->ic_flags_ext);

    in->in_htcap = 0;
    if (ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI20)
        in->in_htcap |= IEEE80211_HTCAP_SHORTGI20;
    if (IEEE80211_IS_CHAN_HT40(in->in_chan)) {
        in->in_htcap |= IEEE80211_HTCAP_CHWIDTH40;
        in->in_chw = 40;
        if (IEEE80211_IS_CHAN_HT40U(in->in_chan))
            in->in_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_ABOVE;
        else if (IEEE80211_IS_CHAN_HT40D(in->in_chan))
            in->in_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_BELOW;
        if (ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI40)
            in->in_htcap |= IEEE80211_HTCAP_SHORTGI40;
    } else {
        in->in_chw = 20;
        in->in_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_NONE;
    }
    in->in_htctlchan = ieee80211_chan2ieee(ic, in->in_chan);

    in->in_htopmode = 0;        /* need protection state */
    in->in_htstbc = 0;      /* need info */

    for (ac = 0; ac < WME_NUM_AC; ac++) {
        tap = &in->in_tx_ampdu[ac];
        tap->txa_ac = (uint8_t)ac;
    }
    /* NB: AMPDU tx/rx governed by IEEE80211_FEXT_AMPDU_{TX,RX} */
    in->in_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
}

/*
 * Notify hostap vaps of a change in the HTINFO ie.
 */
static void
htinfo_notify(struct ieee80211com *ic)
{
    if (ic->ic_opmode != IEEE80211_M_HOSTAP)
        return;
    ieee80211_dbg(IEEE80211_MSG_ASSOC | IEEE80211_MSG_HT,
        "HT bss occupancy change: %d sta, %d ht, "
        "%d ht40%s, HT protmode now 0x%x\n",
        ic->ic_sta_assoc,
        ic->ic_ht_sta_assoc,
        ic->ic_ht40_sta_assoc,
        (ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) ?
        ", non-HT sta present" : "",
        ic->ic_curhtprotmode);
}

/*
 * Calculate HT protection mode from current
 * state and handle updates.
 */
static void
htinfo_update(struct ieee80211com *ic)
{
    uint8_t protmode;

    if (ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) {
        protmode = IEEE80211_HTINFO_OPMODE_PROTOPT
            | IEEE80211_HTINFO_NONHT_PRESENT;
    } else if (ic->ic_sta_assoc != ic->ic_ht_sta_assoc) {
        protmode = IEEE80211_HTINFO_OPMODE_MIXED
            | IEEE80211_HTINFO_NONHT_PRESENT;
    } else if (IEEE80211_IS_CHAN_HT40(ic->ic_curchan) &&
        ic->ic_sta_assoc != ic->ic_ht40_sta_assoc) {
        protmode = IEEE80211_HTINFO_OPMODE_HT20PR;
    } else {
        protmode = IEEE80211_HTINFO_OPMODE_PURE;
    }
    if (protmode != ic->ic_curhtprotmode) {
        ic->ic_curhtprotmode = protmode;
        htinfo_notify(ic);
    }
}

/*
 * Handle an HT station joining a BSS.
 */
void
ieee80211_ht_node_join(struct ieee80211_node *in)
{
    struct ieee80211com *ic = in->in_ic;

    IEEE80211_LOCK_ASSERT(ic);

    if (in->in_flags & IEEE80211_NODE_HT) {
        ic->ic_ht_sta_assoc++;
        if (in->in_chw == 40)
            ic->ic_ht40_sta_assoc++;
    }
    htinfo_update(ic);
}

/*
 * Handle an HT station leaving a BSS.
 */
void
ieee80211_ht_node_leave(struct ieee80211_node *in)
{
    struct ieee80211com *ic = in->in_ic;

    IEEE80211_LOCK_ASSERT(ic);

    if (in->in_flags & IEEE80211_NODE_HT) {
        ic->ic_ht_sta_assoc--;
        if (in->in_chw == 40)
            ic->ic_ht40_sta_assoc--;
    }
    htinfo_update(ic);
}

/*
 * Public version of htinfo_update; used for processing
 * beacon frames from overlapping bss in hostap_recv_mgmt.
 */
void
ieee80211_htinfo_update(struct ieee80211com *ic, int protmode)
{
    if (protmode != ic->ic_curhtprotmode) {
        ic->ic_curhtprotmode = (uint8_t)protmode;
        htinfo_notify(ic);
    }
}

/* unalligned little endian access */
#define LE_READ_2(p)                    \
    ((uint16_t)                 \
    ((((const uint8_t *)(p))[0]) |          \
    (((const uint8_t *)(p))[1] <<  8)))

/*
 * Process an 802.11n HT capabilities ie.
 */
void
ieee80211_parse_htcap(struct ieee80211_node *in, const uint8_t *ie)
{
    struct ieee80211com *ic = in->in_ic;

    if (ie[0] == IEEE80211_ELEMID_VENDOR) {
        /*
         * Station used Vendor OUI ie to associate;
         * mark the node so when we respond we'll use
         * the Vendor OUI's and not the standard ie's.
         */
        in->in_flags |= IEEE80211_NODE_HTCOMPAT;
        ie += 4;
    } else
        in->in_flags &= ~IEEE80211_NODE_HTCOMPAT;

    in->in_htcap = *(uint16_t *)(ie +
        offsetof(struct ieee80211_ie_htcap, hc_cap));
    in->in_htparam = ie[offsetof(struct ieee80211_ie_htcap, hc_param)];
    /* needed or will ieee80211_parse_htinfo always be called? */
    in->in_chw = (in->in_htcap & IEEE80211_HTCAP_CHWIDTH40) &&
        (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40) ? 40 : 20;
}

/*
 * Process an 802.11n HT info ie and update the node state.
 * Note that we handle use this information to identify the
 * correct channel (HT20, HT40+, HT40-, legacy).  The caller
 * is responsible for insuring any required channel change is
 * done (e.g. in sta mode when parsing the contents of a
 * beacon frame).
 */
void
ieee80211_parse_htinfo(struct ieee80211_node *in, const uint8_t *ie)
{
    struct ieee80211com *ic = in->in_ic;
    const struct ieee80211_ie_htinfo *htinfo;
    struct ieee80211_channel *c;
    uint16_t w;
    int htflags, chanflags;

    if (ie[0] == IEEE80211_ELEMID_VENDOR)
        ie += 4;
    htinfo = (const struct ieee80211_ie_htinfo *)ie;
    in->in_htctlchan = htinfo->hi_ctrlchannel;
    in->in_ht2ndchan = SM(htinfo->hi_byte1, IEEE80211_HTINFO_2NDCHAN);
    w = *(uint16_t *)(&htinfo->hi_byte2);
    in->in_htopmode = SM(w, IEEE80211_HTINFO_OPMODE);
    w = *(uint16_t *)(&htinfo->hi_byte45);
    in->in_htstbc = SM(w, IEEE80211_HTINFO_BASIC_STBCMCS);
    /*
     * Handle 11n channel switch.  Use the received HT ie's to
     * identify the right channel to use.  If we cannot locate it
     * in the channel table then fallback to legacy operation.
     */
    htflags = (ic->ic_flags_ext & IEEE80211_FEXT_HT) ?
        IEEE80211_CHAN_HT20 : 0;
    /* NB: honor operating mode constraint */
    if ((htinfo->hi_byte1 & IEEE80211_HTINFO_TXWIDTH_2040) &&
        (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40)) {
        if (in->in_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_ABOVE)
            htflags = IEEE80211_CHAN_HT40U;
        else if (in->in_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_BELOW)
            htflags = IEEE80211_CHAN_HT40D;
    }
    chanflags = (in->in_chan->ich_flags &~ IEEE80211_CHAN_HT) | htflags;
    if (chanflags != in->in_chan->ich_flags) {
        c = ieee80211_find_channel(ic,
            in->in_chan->ich_freq, chanflags);
        if (c == NULL && htflags != IEEE80211_CHAN_HT20) {
            /*
             * No HT40 channel entry in our table; fall back
             * to HT20 operation.  This should not happen.
             */
            c = findhtchan(ic, in->in_chan, IEEE80211_CHAN_HT20);
            ieee80211_dbg(IEEE80211_MSG_ASSOC | IEEE80211_MSG_HT,
                "no HT40 channel (freq %u), falling back to HT20\n",
                in->in_chan->ich_freq);
            /* stat */
        }
        if (c != NULL && c != in->in_chan) {
            ieee80211_dbg(IEEE80211_MSG_ASSOC | IEEE80211_MSG_HT,
                "switch station to HT%d channel %u/0x%x\n",
                IEEE80211_IS_CHAN_HT40(c) ? 40 : 20,
                c->ich_freq, c->ich_flags);
            in->in_chan = c;
        }
        /* NB: caller responsible for forcing any channel change */
    }
    /* update node's tx channel width */
    in->in_chw = IEEE80211_IS_CHAN_HT40(in->in_chan)? 40 : 20;
}

/*
 * Install received HT rate set by parsing the HT cap ie.
 */
int
ieee80211_setup_htrates(struct ieee80211_node *in, const uint8_t *ie, int flags)
{
    const struct ieee80211_ie_htcap *htcap;
    struct ieee80211_htrateset *rs;
    int i;

    rs = &in->in_htrates;
    (void) memset(rs, 0, sizeof (*rs));
    if (ie != NULL) {
        if (ie[0] == IEEE80211_ELEMID_VENDOR)
            ie += 4;
        htcap = (const struct ieee80211_ie_htcap *) ie;
        for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
            if (ieee80211_isclr(htcap->hc_mcsset, i))
                continue;
            if (rs->rs_nrates == IEEE80211_HTRATE_MAXSIZE) {
                ieee80211_dbg(
                    IEEE80211_MSG_XRATE | IEEE80211_MSG_HT,
                    "WARNING, HT rate set too large; only "
                    "using %u rates\n",
                    IEEE80211_HTRATE_MAXSIZE);
                break;
            }
            rs->rs_rates[rs->rs_nrates++] = (uint8_t)i;
        }
    }
    return (ieee80211_fix_rate(in, (struct ieee80211_rateset *)rs, flags));
}

/*
 * Mark rates in a node's HT rate set as basic according
 * to the information in the supplied HT info ie.
 */
void
ieee80211_setup_basic_htrates(struct ieee80211_node *in, const uint8_t *ie)
{
    const struct ieee80211_ie_htinfo *htinfo;
    struct ieee80211_htrateset *rs;
    int i, j;

    if (ie[0] == IEEE80211_ELEMID_VENDOR)
        ie += 4;
    htinfo = (const struct ieee80211_ie_htinfo *) ie;
    rs = &in->in_htrates;
    if (rs->rs_nrates == 0) {
        ieee80211_dbg(IEEE80211_MSG_XRATE | IEEE80211_MSG_HT,
            "WARNING, empty HT rate set\n");
        return;
    }
    for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
        if (ieee80211_isclr(htinfo->hi_basicmcsset, i))
            continue;
        for (j = 0; j < rs->rs_nrates; j++)
            if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == i)
                rs->rs_rates[j] |= IEEE80211_RATE_BASIC;
    }
}

static void
addba_timeout(void *arg)
{
    struct ieee80211_tx_ampdu *tap = arg;

    tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
    tap->txa_attempts++;
}

static void
addba_start_timeout(struct ieee80211_tx_ampdu *tap)
{
    tap->txa_timer = timeout(addba_timeout, (void *)tap,
        drv_usectohz(IEEE80211_AGGR_TIMEOUT * 1000));
    tap->txa_flags |= IEEE80211_AGGR_XCHGPEND;
    tap->txa_lastrequest = ddi_get_lbolt();
}

static void
addba_stop_timeout(struct ieee80211_tx_ampdu *tap)
{
    if (tap->txa_flags & IEEE80211_AGGR_XCHGPEND) {
        if (tap->txa_timer != NULL) {
            (void) untimeout(tap->txa_timer);
            tap->txa_timer = NULL;
        }
        tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
    }
}

/*
 * Default method for requesting A-MPDU tx aggregation.
 * We setup the specified state block and start a timer
 * to wait for an ADDBA response frame.
 */
/* ARGSUSED */
static int
ieee80211_addba_request(struct ieee80211_node *in,
    struct ieee80211_tx_ampdu *tap,
    int dialogtoken, int baparamset, int batimeout)
{
    int bufsiz;

    tap->txa_token = (uint8_t)dialogtoken;
    tap->txa_flags |= IEEE80211_AGGR_IMMEDIATE;
    tap->txa_start = tap->txa_seqstart = 0;
    bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
    tap->txa_wnd = (bufsiz == 0) ? IEEE80211_AGGR_BAWMAX
        : min((uint16_t)bufsiz, IEEE80211_AGGR_BAWMAX);
    addba_start_timeout(tap);
    return (1);
}

/*
 * Default method for processing an A-MPDU tx aggregation
 * response.  We shutdown any pending timer and update the
 * state block according to the reply.
 */
/* ARGSUSED */
static int
ieee80211_addba_response(struct ieee80211_node *in,
    struct ieee80211_tx_ampdu *tap,
    int status, int baparamset, int batimeout)
{
    int bufsiz;

    addba_stop_timeout(tap);
    if (status == IEEE80211_STATUS_SUCCESS) {
        bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
        /* override our request? */
        tap->txa_wnd = (bufsiz == 0) ? IEEE80211_AGGR_BAWMAX
            : min((uint16_t)bufsiz, IEEE80211_AGGR_BAWMAX);
        tap->txa_flags |= IEEE80211_AGGR_RUNNING;
    } else {
        /* mark tid so we don't try again */
        tap->txa_flags |= IEEE80211_AGGR_NAK;
    }
    return (1);
}

/*
 * Default method for stopping A-MPDU tx aggregation.
 * Any timer is cleared and we drain any pending frames.
 */
/* ARGSUSED */
static void
ieee80211_addba_stop(struct ieee80211_node *in, struct ieee80211_tx_ampdu *tap)
{
    addba_stop_timeout(tap);
    if (tap->txa_flags & IEEE80211_AGGR_RUNNING) {
        /* clear aggregation queue */
        tap->txa_flags &= ~IEEE80211_AGGR_RUNNING;
    }
    tap->txa_attempts = 0;
}

/*
 * Process a received action frame using the default aggregation
 * policy.  We intercept ADDBA-related frames and use them to
 * update our aggregation state.  All other frames are passed up
 * for processing by ieee80211_recv_action.
 */
static void
ieee80211_aggr_recv_action(struct ieee80211_node *in,
    const uint8_t *frm, const uint8_t *efrm)
{
    struct ieee80211com *ic = in->in_ic;
    const struct ieee80211_action *ia;
    struct ieee80211_rx_ampdu *rap;
    struct ieee80211_tx_ampdu *tap;
    uint8_t dialogtoken;
    uint16_t baparamset, batimeout, baseqctl, code;
    uint16_t args[4];
    int tid, ac, bufsiz;

    ia = (const struct ieee80211_action *) frm;
    switch (ia->ia_category) {
    case IEEE80211_ACTION_CAT_BA:
        switch (ia->ia_action) {
        case IEEE80211_ACTION_BA_ADDBA_REQUEST:
            dialogtoken = frm[2];
            baparamset = *(uint16_t *)(frm+3);
            batimeout = *(uint16_t *)(frm+5);
            baseqctl = *(uint16_t *)(frm+7);

            tid = MS(baparamset, IEEE80211_BAPS_TID);
            bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);

            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "recv ADDBA request: dialogtoken %u "
                "baparamset 0x%x (tid %d bufsiz %d) batimeout %d "
                "baseqctl %d:%d\n",
                dialogtoken, baparamset, tid, bufsiz, batimeout,
                MS(baseqctl, IEEE80211_BASEQ_START),
                MS(baseqctl, IEEE80211_BASEQ_FRAG));

            rap = &in->in_rx_ampdu[tid];

            /* Send ADDBA response */
            args[0] = dialogtoken;
            /*
             * NB: We ack only if the sta associated with HT and
             * the ap is configured to do AMPDU rx (the latter
             * violates the 11n spec and is mostly for testing).
             */
            if ((in->in_flags & IEEE80211_NODE_AMPDU_RX) &&
                (ic->ic_flags_ext & IEEE80211_FEXT_AMPDU_RX)) {
                ampdu_rx_start(rap, bufsiz,
                    MS(baseqctl, IEEE80211_BASEQ_START));

                args[1] = IEEE80211_STATUS_SUCCESS;
            } else {
                ieee80211_dbg(
                    IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                    "reject ADDBA request: %s\n",
                    in->in_flags & IEEE80211_NODE_AMPDU_RX ?
                    "administratively disabled" :
                    "not negotiated for station");
                args[1] = IEEE80211_STATUS_UNSPECIFIED;
            }
            /* honor rap flags? */
            args[2] = IEEE80211_BAPS_POLICY_IMMEDIATE
                | SM(tid, IEEE80211_BAPS_TID)
                | SM(rap->rxa_wnd, IEEE80211_BAPS_BUFSIZ);
            args[3] = 0;
            ic->ic_send_action(in, IEEE80211_ACTION_CAT_BA,
                IEEE80211_ACTION_BA_ADDBA_RESPONSE, args);
            return;

        case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
            dialogtoken = frm[2];
            code = *(uint16_t *)(frm+3);
            baparamset = *(uint16_t *)(frm+5);
            tid = MS(baparamset, IEEE80211_BAPS_TID);
            bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
            batimeout = *(uint16_t *)(frm+7);

            ac = TID_TO_WME_AC(tid);
            tap = &in->in_tx_ampdu[ac];
            if ((tap->txa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
                ieee80211_err("ADDBA response"
                    "no pending ADDBA, tid %d dialogtoken %u "
                    "code %d\n", tid, dialogtoken, code);
                return;
            }
            if (dialogtoken != tap->txa_token) {
                ieee80211_err("ADDBA response"
                    "dialogtoken mismatch: waiting for %d, "
                    "received %d, tid %d code %d\n",
                    tap->txa_token, dialogtoken, tid, code);
                return;
            }

            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "recv ADDBA response: dialogtoken %u code %d "
                "baparamset 0x%x (tid %d bufsiz %d) batimeout %d\n",
                dialogtoken, code, baparamset, tid, bufsiz,
                batimeout);
            ic->ic_addba_response(in, tap,
                code, baparamset, batimeout);
            return;

        case IEEE80211_ACTION_BA_DELBA:
            baparamset = *(uint16_t *)(frm+2);
            code = *(uint16_t *)(frm+4);

            tid = MS(baparamset, IEEE80211_DELBAPS_TID);

            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "recv DELBA: baparamset 0x%x (tid %d initiator %d) "
                "code %d\n", baparamset, tid,
                MS(baparamset, IEEE80211_DELBAPS_INIT), code);

            if ((baparamset & IEEE80211_DELBAPS_INIT) == 0) {
                ac = TID_TO_WME_AC(tid);
                tap = &in->in_tx_ampdu[ac];
                ic->ic_addba_stop(in, tap);
            } else {
                rap = &in->in_rx_ampdu[tid];
                ampdu_rx_stop(rap);
            }
            return;
        }
        break;
    }
    ieee80211_recv_action(in, frm, efrm);
}

/*
 * Process a received 802.11n action frame.
 * Aggregation-related frames are assumed to be handled
 * already; we handle any other frames we can, otherwise
 * complain about being unsupported (with debugging).
 */
/* ARGSUSED */
void
ieee80211_recv_action(struct ieee80211_node *in,
    const uint8_t *frm, const uint8_t *efrm)
{
    const struct ieee80211_action *ia;
    int chw;

    ia = (const struct ieee80211_action *) frm;
    switch (ia->ia_category) {
    case IEEE80211_ACTION_CAT_BA:
        ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
            "BA action %d not implemented\n",
            ia->ia_action);
        break;
    case IEEE80211_ACTION_CAT_HT:
        switch (ia->ia_action) {
        case IEEE80211_ACTION_HT_TXCHWIDTH:
            chw = frm[2] == IEEE80211_A_HT_TXCHWIDTH_2040 ? 40 : 20;
            if (chw != in->in_chw) {
                in->in_chw = (uint8_t)chw;
                in->in_flags |= IEEE80211_NODE_CHWUPDATE;
            }
            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "HT txchwidth, width %d (%s)\n",
                chw,
                in->in_flags & IEEE80211_NODE_CHWUPDATE ?
                "new" : "no change");
            break;
        case IEEE80211_ACTION_HT_MIMOPWRSAVE:
            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "HT MIMO PS\n");
            break;
        default:
            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "HT action %d not implemented\n",
                ia->ia_action);
            break;
        }
        break;
    default:
        ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
            "category %d not implemented\n",
            ia->ia_category);
        break;
    }
}

/*
 * Transmit processing.
 */

/*
 * Request A-MPDU tx aggregation.  Setup local state and
 * issue an ADDBA request.  BA use will only happen after
 * the other end replies with ADDBA response.
 */
int
ieee80211_ampdu_request(struct ieee80211_node *in,
    struct ieee80211_tx_ampdu *tap)
{
    struct ieee80211com *ic = in->in_ic;
    uint16_t args[4];
    int tid, dialogtoken;
    static int tokens = 0;  /* tokens */
    clock_t ticks;

    ticks = ddi_get_lbolt();
    if ((tap->txa_flags & IEEE80211_AGGR_SETUP) == 0) {
        /* do deferred setup of state */
        tap->txa_flags |= IEEE80211_AGGR_SETUP;
    }
    if (tap->txa_attempts >= IEEE80211_AGGR_MAXTRIES &&
        (ticks - tap->txa_lastrequest) < IEEE80211_AGGR_MINRETRY) {
        /*
         * Don't retry too often; IEEE80211_AGGR_MINRETRY
         * defines the minimum interval we'll retry after
         * IEEE80211_AGGR_MAXTRIES failed attempts to
         * negotiate use.
         */
        return (0);
    }
    /* hack for not doing proper locking */
    tap->txa_flags &= ~IEEE80211_AGGR_NAK;

    dialogtoken = (tokens+1) % 63;      /* algorithm */

    tid = WME_AC_TO_TID(tap->txa_ac);
    args[0] = (uint16_t)dialogtoken;
    args[1] = IEEE80211_BAPS_POLICY_IMMEDIATE
        | SM(tid, IEEE80211_BAPS_TID)
        | SM(IEEE80211_AGGR_BAWMAX, IEEE80211_BAPS_BUFSIZ);
    args[2] = 0;    /* batimeout */
    args[3] = SM(0, IEEE80211_BASEQ_START)
        | SM(0, IEEE80211_BASEQ_FRAG);
    /* NB: do first so there's no race against reply */
    if (!ic->ic_addba_request(in, tap, dialogtoken, args[1], args[2])) {
        /* unable to setup state, don't make request */
        ieee80211_dbg(IEEE80211_MSG_HT,
            "could not setup BA stream for AC %d\n",
            tap->txa_ac);
        /* defer next try so we don't slam the driver with requests */
        tap->txa_attempts = IEEE80211_AGGR_MAXTRIES;
        tap->txa_lastrequest = ticks;
        return (0);
    }
    tokens = dialogtoken;           /* allocate token */
    return (ic->ic_send_action(in, IEEE80211_ACTION_CAT_BA,
        IEEE80211_ACTION_BA_ADDBA_REQUEST, args));
}

/*
 * Terminate an AMPDU tx stream. State is reclaimed
 * and the peer notified with a DelBA Action frame.
 */
void
ieee80211_ampdu_stop(struct ieee80211_node *in, struct ieee80211_tx_ampdu *tap)
{
    struct ieee80211com *ic = in->in_ic;
    uint16_t args[4];

    if (IEEE80211_AMPDU_RUNNING(tap)) {
        ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
            "stop BA stream for AC %d\n", tap->txa_ac);

        ic->ic_addba_stop(in, tap);
        args[0] = WME_AC_TO_TID(tap->txa_ac);
        args[1] = IEEE80211_DELBAPS_INIT;
        args[2] = 1;                /* reason code */
        (void) ieee80211_send_action(in, IEEE80211_ACTION_CAT_BA,
            IEEE80211_ACTION_BA_DELBA, args);
    } else {
        ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
            "BA stream for AC %d not running\n",
            tap->txa_ac);
    }
}

/*
 * Transmit a BAR frame to the specified node.  The
 * BAR contents are drawn from the supplied aggregation
 * state associated with the node.
 */
int
ieee80211_send_bar(struct ieee80211_node *in,
    const struct ieee80211_tx_ampdu *tap)
{
#define ADDSHORT(frm, v) do {           \
        _NOTE(CONSTCOND)                        \
    frm[0] = (v) & 0xff;            \
    frm[1] = (v) >> 8;          \
    frm += 2;               \
        _NOTE(CONSTCOND)                        \
} while (0)
    struct ieee80211com *ic = in->in_ic;
    struct ieee80211_frame_min *wh;
    mblk_t *m;
    uint8_t *frm;
    uint16_t barctl, barseqctl;
    int tid;


    m = ieee80211_getmgtframe(&frm, sizeof (struct ieee80211_ba_request));
    if (m == NULL)
        return (ENOMEM);

    wh = (struct ieee80211_frame_min *)m->b_rptr;
    wh->i_fc[0] = IEEE80211_FC0_VERSION_0 |
        IEEE80211_FC0_TYPE_CTL | IEEE80211_FC0_SUBTYPE_BAR;
    wh->i_fc[1] = 0;
    IEEE80211_ADDR_COPY(wh->i_addr1, in->in_macaddr);
    IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_macaddr);

    tid = WME_AC_TO_TID(tap->txa_ac);
    barctl  = (tap->txa_flags & IEEE80211_AGGR_IMMEDIATE ?
        IEEE80211_BAPS_POLICY_IMMEDIATE :
        IEEE80211_BAPS_POLICY_DELAYED)
        | SM(tid, IEEE80211_BAPS_TID)
        | SM(tap->txa_wnd, IEEE80211_BAPS_BUFSIZ);
    barseqctl = SM(tap->txa_start, IEEE80211_BASEQ_START)
        | SM(0, IEEE80211_BASEQ_FRAG);
    ADDSHORT(frm, barctl);
    ADDSHORT(frm, barseqctl);
    m->b_wptr = frm;

    ieee80211_dbg(IEEE80211_MSG_DEBUG,
        "send bar frame (tid %u start %u) on channel %u\n",
        tid, tap->txa_start, ieee80211_chan2ieee(ic, ic->ic_curchan));

    (void) (*ic->ic_xmit)(ic, m, IEEE80211_FC0_TYPE_CTL);   /* MGT? */

    return (0);
#undef ADDSHORT
}

/*
 * Send an action management frame.  The arguments are stuff
 * into a frame without inspection; the caller is assumed to
 * prepare them carefully (e.g. based on the aggregation state).
 */
int
ieee80211_send_action(struct ieee80211_node *in,
    int category, int action, uint16_t args[4])
{
#define ADDSHORT(frm, v) do {           \
        _NOTE(CONSTCOND)                        \
    frm[0] = (v) & 0xff;            \
    frm[1] = (v) >> 8;          \
    frm += 2;               \
        _NOTE(CONSTCOND)                        \
} while (0)
    struct ieee80211com *ic = in->in_ic;
    mblk_t *m;
    uint8_t *frm;
    uint16_t baparamset;
    int ret;

    ASSERT(in != NULL);

    m = ieee80211_getmgtframe(&frm,
        sizeof (uint16_t)   /* action+category */
        /* may action payload */
        + sizeof (struct ieee80211_action_ba_addbaresponse));
    if (m == NULL)
        return (ENOMEM);

    *frm++ = (uint8_t)category;
    *frm++ = (uint8_t)action;
    switch (category) {
    case IEEE80211_ACTION_CAT_BA:
        switch (action) {
        case IEEE80211_ACTION_BA_ADDBA_REQUEST:
            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "send ADDBA request: dialogtoken %d "
                "baparamset 0x%x (tid %d) "
                "batimeout 0x%x baseqctl 0x%x\n",
                args[0], args[1], MS(args[1], IEEE80211_BAPS_TID),
                args[2], args[3]);

            *frm++ = args[0];   /* dialog token */
            ADDSHORT(frm, args[1]); /* baparamset */
            ADDSHORT(frm, args[2]); /* batimeout */
            ADDSHORT(frm, args[3]); /* baseqctl */
            break;
        case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "send ADDBA response: dialogtoken %d status %d "
                "baparamset 0x%x (tid %d) batimeout %d\n",
                args[0], args[1], args[2],
                MS(args[2], IEEE80211_BAPS_TID), args[3]);

            *frm++ = args[0];   /* dialog token */
            ADDSHORT(frm, args[1]); /* statuscode */
            ADDSHORT(frm, args[2]); /* baparamset */
            ADDSHORT(frm, args[3]); /* batimeout */
            break;
        case IEEE80211_ACTION_BA_DELBA:
            baparamset = SM(args[0], IEEE80211_DELBAPS_TID)
                | SM(args[1], IEEE80211_DELBAPS_INIT);
            ADDSHORT(frm, baparamset);
            ADDSHORT(frm, args[2]); /* reason code */

            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "send DELBA action: tid %d, initiator %d "
                "reason %d\n",
                args[0], args[1], args[2]);
            break;
        default:
            goto badaction;
        }
        break;
    case IEEE80211_ACTION_CAT_HT:
        switch (action) {
        case IEEE80211_ACTION_HT_TXCHWIDTH:
            ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
                "send HT txchwidth: width %d\n",
                IEEE80211_IS_CHAN_HT40(ic->ic_curchan) ? 40 : 20);
            *frm++ = IEEE80211_IS_CHAN_HT40(ic->ic_curchan) ?
                IEEE80211_A_HT_TXCHWIDTH_2040 :
                IEEE80211_A_HT_TXCHWIDTH_20;
            break;
        default:
            goto badaction;
        }
        break;
    default:
    badaction:
        ieee80211_dbg(IEEE80211_MSG_ACTION | IEEE80211_MSG_HT,
            "unsupported category %d action %d\n",
            category, action);
        return (EINVAL);
        /* NOTREACHED */
    }
    m->b_wptr = frm;

    ret = ieee80211_mgmt_output(ic, in, m, IEEE80211_FC0_SUBTYPE_ACTION, 0);

    return (ret);
#undef ADDSHORT
}

/*
 * Construct the MCS bit mask for inclusion
 * in an HT information element.
 */
static void
ieee80211_set_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
{
    int i;

    for (i = 0; i < rs->rs_nrates; i++) {
        int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
        if (r < IEEE80211_HTRATE_MAXSIZE) {
            /* NB: this assumes a particular implementation */
            ieee80211_setbit(frm, r);
        }
    }
}

/*
 * Add body of an HTCAP information element.
 */
static uint8_t *
ieee80211_add_htcap_body(uint8_t *frm, struct ieee80211_node *in)
{
#define ADDSHORT(frm, v) do {           \
        _NOTE(CONSTCOND)                        \
    frm[0] = (v) & 0xff;            \
    frm[1] = (v) >> 8;          \
    frm += 2;               \
        _NOTE(CONSTCOND)                        \
} while (0)
    struct ieee80211com *ic = in->in_ic;
    uint16_t caps;
    int rxmax, density;

    /* HT capabilities */
    caps = ic->ic_htcaps & 0xffff;
    /*
     * Note channel width depends on whether we are operating as
     * a sta or not.  When operating as a sta we are generating
     * a request based on our desired configuration.  Otherwise
     * we are operational and the channel attributes identify
     * how we've been setup (which might be different if a fixed
     * channel is specified).
     */
    if (ic->ic_opmode == IEEE80211_M_STA) {
        /* override 20/40 use based on config */
        if (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40)
            caps |= IEEE80211_HTCAP_CHWIDTH40;
        else
            caps &= ~IEEE80211_HTCAP_CHWIDTH40;
        /* use advertised setting (locally constraint) */
        rxmax = MS(in->in_htparam, IEEE80211_HTCAP_MAXRXAMPDU);
        density = MS(in->in_htparam, IEEE80211_HTCAP_MPDUDENSITY);
    } else {
        /* override 20/40 use based on current channel */
        if (IEEE80211_IS_CHAN_HT40(ic->ic_curchan))
            caps |= IEEE80211_HTCAP_CHWIDTH40;
        else
            caps &= ~IEEE80211_HTCAP_CHWIDTH40;
        rxmax = ic->ic_ampdu_rxmax;
        density = ic->ic_ampdu_density;
    }
    /* adjust short GI based on channel and config */
    if ((ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI20) == 0)
        caps &= ~IEEE80211_HTCAP_SHORTGI20;
    if ((ic->ic_flags_ext & IEEE80211_FEXT_SHORTGI40) == 0 ||
        (caps & IEEE80211_HTCAP_CHWIDTH40) == 0)
        caps &= ~IEEE80211_HTCAP_SHORTGI40;
    ADDSHORT(frm, caps);

    /* HT parameters */
    *frm = SM(rxmax, IEEE80211_HTCAP_MAXRXAMPDU)
        | SM(density, IEEE80211_HTCAP_MPDUDENSITY);
    frm++;

    /* pre-zero remainder of ie */
    (void) memset(frm, 0, sizeof (struct ieee80211_ie_htcap) -
        offsetof(struct ieee80211_ie_htcap, hc_mcsset));

    /* supported MCS set */
    /*
     * it would better to get the rate set from in_htrates
     * so we can restrict it but for sta mode in_htrates isn't
     * setup when we're called to form an AssocReq frame so for
     * now we're restricted to the default HT rate set.
     */
    ieee80211_set_htrates(frm, &ieee80211_rateset_11n);

    frm += sizeof (struct ieee80211_ie_htcap) -
        offsetof(struct ieee80211_ie_htcap, hc_mcsset);

    return (frm);
#undef ADDSHORT
}

/*
 * Add 802.11n HT capabilities information element
 */
uint8_t *
ieee80211_add_htcap(uint8_t *frm, struct ieee80211_node *in)
{
    frm[0] = IEEE80211_ELEMID_HTCAP;
    frm[1] = sizeof (struct ieee80211_ie_htcap) - 2;
    return (ieee80211_add_htcap_body(frm + 2, in));
}

/*
 * Add Broadcom OUI wrapped standard HTCAP ie; this is
 * used for compatibility w/ pre-draft implementations.
 */
uint8_t *
ieee80211_add_htcap_vendor(uint8_t *frm, struct ieee80211_node *in)
{
    frm[0] = IEEE80211_ELEMID_VENDOR;
    frm[1] = 4 + sizeof (struct ieee80211_ie_htcap) - 2;
    frm[2] = (BCM_OUI >> 0) & 0xff;
    frm[3] = (BCM_OUI >> 8) & 0xff;
    frm[4] = (BCM_OUI >> 16) & 0xff;
    frm[5] = BCM_OUI_HTCAP;
    return (ieee80211_add_htcap_body(frm + 6, in));
}

/*
 * Construct the MCS bit mask of basic rates
 * for inclusion in an HT information element.
 */
static void
ieee80211_set_basic_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
{
    int i;

    for (i = 0; i < rs->rs_nrates; i++) {
        int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
        if ((rs->rs_rates[i] & IEEE80211_RATE_BASIC) &&
            r < IEEE80211_HTRATE_MAXSIZE) {
            /* NB: this assumes a particular implementation */
            ieee80211_setbit(frm, r);
        }
    }
}

/*
 * Update the HTINFO ie for a beacon frame.
 */
void
ieee80211_ht_update_beacon(struct ieee80211com *ic,
    struct ieee80211_beacon_offsets *bo)
{
#define PROTMODE    (IEEE80211_HTINFO_OPMODE|IEEE80211_HTINFO_NONHT_PRESENT)
    struct ieee80211_ie_htinfo *ht =
        (struct ieee80211_ie_htinfo *)bo->bo_htinfo;

    /* only update on channel change */
    ht->hi_ctrlchannel = ieee80211_chan2ieee(ic, ic->ic_curchan);
    ht->hi_byte1 = IEEE80211_HTINFO_RIFSMODE_PROH;
    if (IEEE80211_IS_CHAN_HT40U(ic->ic_curchan))
        ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
    else if (IEEE80211_IS_CHAN_HT40D(ic->ic_curchan))
        ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_BELOW;
    else    /* LINTED */
        ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_NONE;
    if (IEEE80211_IS_CHAN_HT40(ic->ic_curchan))
        ht->hi_byte1 |= IEEE80211_HTINFO_TXWIDTH_2040;

    /* protection mode */
    ht->hi_byte2 = (ht->hi_byte2 &~ PROTMODE) | ic->ic_curhtprotmode;

    /* propagate to vendor ie's */
#undef PROTMODE
}

/*
 * Add body of an HTINFO information element.
 *
 * NB: We don't use struct ieee80211_ie_htinfo because we can
 * be called to fillin both a standard ie and a compat ie that
 * has a vendor OUI at the front.
 */
static uint8_t *
ieee80211_add_htinfo_body(uint8_t *frm, struct ieee80211_node *in)
{
    struct ieee80211com *ic = in->in_ic;

    /* pre-zero remainder of ie */
    (void) memset(frm, 0, sizeof (struct ieee80211_ie_htinfo) - 2);

    /* primary/control channel center */
    *frm++ = ieee80211_chan2ieee(ic, ic->ic_curchan);

    frm[0] = IEEE80211_HTINFO_RIFSMODE_PROH;
    if (IEEE80211_IS_CHAN_HT40U(ic->ic_curchan))
        frm[0] |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
    else if (IEEE80211_IS_CHAN_HT40D(ic->ic_curchan))
        frm[0] |= IEEE80211_HTINFO_2NDCHAN_BELOW;
    else    /* LINTED */
        frm[0] |= IEEE80211_HTINFO_2NDCHAN_NONE;
    if (IEEE80211_IS_CHAN_HT40(ic->ic_curchan))
        frm[0] |= IEEE80211_HTINFO_TXWIDTH_2040;

    frm[1] = ic->ic_curhtprotmode;

    frm += 5;

    /* basic MCS set */
    ieee80211_set_basic_htrates(frm, &in->in_htrates);
    frm += sizeof (struct ieee80211_ie_htinfo) -
        offsetof(struct ieee80211_ie_htinfo, hi_basicmcsset);
    return (frm);
}

/*
 * Add 802.11n HT information information element.
 */
uint8_t *
ieee80211_add_htinfo(uint8_t *frm, struct ieee80211_node *in)
{
    frm[0] = IEEE80211_ELEMID_HTINFO;
    frm[1] = sizeof (struct ieee80211_ie_htinfo) - 2;

    return (ieee80211_add_htinfo_body(frm + 2, in));
}

/*
 * Add Broadcom OUI wrapped standard HTINFO ie; this is
 * used for compatibility w/ pre-draft implementations.
 */
uint8_t *
ieee80211_add_htinfo_vendor(uint8_t *frm, struct ieee80211_node *in)
{
    frm[0] = IEEE80211_ELEMID_VENDOR;
    frm[1] = 4 + sizeof (struct ieee80211_ie_htinfo) - 2;
    frm[2] = (BCM_OUI >> 0) & 0xff;
    frm[3] = (BCM_OUI >> 8) & 0xff;
    frm[4] = (BCM_OUI >> 16) & 0xff;
    frm[5] = BCM_OUI_HTINFO;

    return (ieee80211_add_htinfo_body(frm + 6, in));
}

void
ieee80211_ht_attach(struct ieee80211com *ic)
{
    /* setup default aggregation policy */
    ic->ic_recv_action = ieee80211_aggr_recv_action;
    ic->ic_send_action = ieee80211_send_action;
    ic->ic_addba_request = ieee80211_addba_request;
    ic->ic_addba_response = ieee80211_addba_response;
    ic->ic_addba_stop = ieee80211_addba_stop;

    ic->ic_htprotmode = IEEE80211_PROT_RTSCTS;
    ic->ic_curhtprotmode = IEEE80211_HTINFO_OPMODE_PURE;

    /* get from driver */
    ic->ic_ampdu_rxmax = IEEE80211_HTCAP_MAXRXAMPDU_8K;
    ic->ic_ampdu_density = IEEE80211_HTCAP_MPDUDENSITY_NA;
    ic->ic_ampdu_limit = ic->ic_ampdu_rxmax;
    ic->ic_amsdu_limit = IEEE80211_HTCAP_MAXAMSDU_3839;

    if (ic->ic_htcaps & IEEE80211_HTC_HT) {
        /*
         * Device is HT capable; enable all HT-related
         * facilities by default.
         * these choices may be too aggressive.
         */
        ic->ic_flags_ext |= IEEE80211_FEXT_HT | IEEE80211_FEXT_HTCOMPAT;
        if (ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20)
            ic->ic_flags_ext |= IEEE80211_FEXT_SHORTGI20;
        /* infer from channel list? */
        if (ic->ic_htcaps & IEEE80211_HTCAP_CHWIDTH40) {
            ic->ic_flags_ext |= IEEE80211_FEXT_USEHT40;
            if (ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40)
                ic->ic_flags_ext |= IEEE80211_FEXT_SHORTGI40;
        }
        /* NB: A-MPDU and A-MSDU rx are mandated, these are tx only */
        ic->ic_flags_ext |= IEEE80211_FEXT_AMPDU_RX;
        if (ic->ic_htcaps & IEEE80211_HTC_AMPDU)
            ic->ic_flags_ext |= IEEE80211_FEXT_AMPDU_TX;
        ic->ic_flags_ext |= IEEE80211_FEXT_AMSDU_RX;
        if (ic->ic_htcaps & IEEE80211_HTC_AMSDU)
            ic->ic_flags_ext |= IEEE80211_FEXT_AMSDU_TX;
    }

#define ieee80211_isset16(a, i) ((a) & (1 << (i)))
    /* fill default rate sets for 11NA/11NG if driver has no specified */
    if (ieee80211_isset16(ic->ic_modecaps, IEEE80211_MODE_11NA) &&
        ic->ic_sup_rates[IEEE80211_MODE_11NA].ir_nrates == 0) {
        ic->ic_sup_rates[IEEE80211_MODE_11NA] =
            ic->ic_sup_rates[IEEE80211_MODE_11A];
    }

    if (ieee80211_isset16(ic->ic_modecaps, IEEE80211_MODE_11NG) &&
        ic->ic_sup_rates[IEEE80211_MODE_11NG].ir_nrates == 0) {
        ic->ic_sup_rates[IEEE80211_MODE_11NG] =
            ic->ic_sup_rates[IEEE80211_MODE_11G];
    }
#undef ieee80211_isset16
}

/* ARGSUSED */
void
ieee80211_ht_detach(struct ieee80211com *ic)
{
}

/* ARGSUSED */
static void
ht_announce(struct ieee80211com *ic, int mode,
    const struct ieee80211_htrateset *rs)
{
    int i, rate;

    ieee80211_dbg(IEEE80211_MSG_HT, "%s MCS: \n",
        ieee80211_phymode_name[mode]);
    for (i = 0; i < rs->rs_nrates; i++) {
        rate = ieee80211_htrates[rs->rs_rates[i]];
        ieee80211_dbg(IEEE80211_MSG_HT, "%s%d%sMbps\n",
            (i != 0 ? " " : ""),
            rate / 2, ((rate & 0x1) != 0 ? ".5" : ""));
    }
}

void
ieee80211_ht_announce(struct ieee80211com *ic)
{
    if (ic->ic_modecaps & (1 << IEEE80211_MODE_11NA))
        ht_announce(ic, IEEE80211_MODE_11NA, &ieee80211_rateset_11n);
    if (ic->ic_modecaps & (1 << IEEE80211_MODE_11NG))
        ht_announce(ic, IEEE80211_MODE_11NG, &ieee80211_rateset_11n);
}

/* ARGSUSED */
const struct ieee80211_htrateset *
ieee80211_get_suphtrates(struct ieee80211com *ic,
    const struct ieee80211_channel *c)
{
    return (&ieee80211_rateset_11n);
}