loader: Minor cosmetic changes.

[unleashed.git] / kernel / net / 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);
}