xref: /freebsd/sys/net80211/ieee80211_ht.c (revision f7c4bd95ba735bd6a5454b4953945a99cefbb80c)
1 /*-
2  * Copyright (c) 2007-2008 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 #ifdef __FreeBSD__
28 __FBSDID("$FreeBSD$");
29 #endif
30 
31 /*
32  * IEEE 802.11n protocol support.
33  */
34 
35 #include "opt_inet.h"
36 #include "opt_wlan.h"
37 
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/systm.h>
41 #include <sys/endian.h>
42 
43 #include <sys/socket.h>
44 
45 #include <net/if.h>
46 #include <net/if_media.h>
47 #include <net/ethernet.h>
48 
49 #include <net80211/ieee80211_var.h>
50 #include <net80211/ieee80211_input.h>
51 
52 /* define here, used throughout file */
53 #define	MS(_v, _f)	(((_v) & _f) >> _f##_S)
54 #define	SM(_v, _f)	(((_v) << _f##_S) & _f)
55 
56 const struct ieee80211_mcs_rates ieee80211_htrates[16] = {
57 	{  13,  14,  27,  30 },	/* MCS 0 */
58 	{  26,  29,  54,  60 },	/* MCS 1 */
59 	{  39,  43,  81,  90 },	/* MCS 2 */
60 	{  52,  58, 108, 120 },	/* MCS 3 */
61 	{  78,  87, 162, 180 },	/* MCS 4 */
62 	{ 104, 116, 216, 240 },	/* MCS 5 */
63 	{ 117, 130, 243, 270 },	/* MCS 6 */
64 	{ 130, 144, 270, 300 },	/* MCS 7 */
65 	{  26,  29,  54,  60 },	/* MCS 8 */
66 	{  52,  58, 108, 120 },	/* MCS 9 */
67 	{  78,  87, 162, 180 },	/* MCS 10 */
68 	{ 104, 116, 216, 240 },	/* MCS 11 */
69 	{ 156, 173, 324, 360 },	/* MCS 12 */
70 	{ 208, 231, 432, 480 },	/* MCS 13 */
71 	{ 234, 260, 486, 540 },	/* MCS 14 */
72 	{ 260, 289, 540, 600 }	/* MCS 15 */
73 };
74 
75 static const struct ieee80211_htrateset ieee80211_rateset_11n =
76 	{ 16, {
77 	          0,   1,   2,   3,   4,  5,   6,  7,  8,  9,
78 		 10,  11,  12,  13,  14,  15 }
79 	};
80 
81 #ifdef IEEE80211_AMPDU_AGE
82 /* XXX public for sysctl hookup */
83 int	ieee80211_ampdu_age = -1;	/* threshold for ampdu reorder q (ms) */
84 #endif
85 int	ieee80211_recv_bar_ena = 1;
86 int	ieee80211_addba_timeout = -1;	/* timeout waiting for ADDBA response */
87 int	ieee80211_addba_backoff = -1;	/* backoff after max ADDBA requests */
88 int	ieee80211_addba_maxtries = 3;	/* max ADDBA requests before backoff */
89 
90 /*
91  * Setup HT parameters that depends on the clock frequency.
92  */
93 static void
94 ieee80211_ht_setup(void)
95 {
96 #ifdef IEEE80211_AMPDU_AGE
97 	ieee80211_ampdu_age = msecs_to_ticks(500);
98 #endif
99 	ieee80211_addba_timeout = msecs_to_ticks(250);
100 	ieee80211_addba_backoff = msecs_to_ticks(10*1000);
101 }
102 SYSINIT(wlan_ht, SI_SUB_DRIVERS, SI_ORDER_FIRST, ieee80211_ht_setup, NULL);
103 
104 static int ieee80211_ampdu_enable(struct ieee80211_node *ni,
105 	struct ieee80211_tx_ampdu *tap);
106 static int ieee80211_addba_request(struct ieee80211_node *ni,
107 	struct ieee80211_tx_ampdu *tap,
108 	int dialogtoken, int baparamset, int batimeout);
109 static int ieee80211_addba_response(struct ieee80211_node *ni,
110 	struct ieee80211_tx_ampdu *tap,
111 	int code, int baparamset, int batimeout);
112 static void ieee80211_addba_stop(struct ieee80211_node *ni,
113 	struct ieee80211_tx_ampdu *tap);
114 static void ieee80211_aggr_recv_action(struct ieee80211_node *ni,
115 	const uint8_t *frm, const uint8_t *efrm);
116 
117 void
118 ieee80211_ht_attach(struct ieee80211com *ic)
119 {
120 	/* setup default aggregation policy */
121 	ic->ic_recv_action = ieee80211_aggr_recv_action;
122 	ic->ic_send_action = ieee80211_send_action;
123 	ic->ic_ampdu_enable = ieee80211_ampdu_enable;
124 	ic->ic_addba_request = ieee80211_addba_request;
125 	ic->ic_addba_response = ieee80211_addba_response;
126 	ic->ic_addba_stop = ieee80211_addba_stop;
127 
128 	ic->ic_htprotmode = IEEE80211_PROT_RTSCTS;
129 	ic->ic_curhtprotmode = IEEE80211_HTINFO_OPMODE_PURE;
130 }
131 
132 void
133 ieee80211_ht_detach(struct ieee80211com *ic)
134 {
135 }
136 
137 void
138 ieee80211_ht_vattach(struct ieee80211vap *vap)
139 {
140 
141 	/* driver can override defaults */
142 	vap->iv_ampdu_rxmax = IEEE80211_HTCAP_MAXRXAMPDU_8K;
143 	vap->iv_ampdu_density = IEEE80211_HTCAP_MPDUDENSITY_NA;
144 	vap->iv_ampdu_limit = vap->iv_ampdu_rxmax;
145 	vap->iv_amsdu_limit = vap->iv_htcaps & IEEE80211_HTCAP_MAXAMSDU;
146 	/* tx aggregation traffic thresholds */
147 	vap->iv_ampdu_mintraffic[WME_AC_BK] = 128;
148 	vap->iv_ampdu_mintraffic[WME_AC_BE] = 64;
149 	vap->iv_ampdu_mintraffic[WME_AC_VO] = 32;
150 	vap->iv_ampdu_mintraffic[WME_AC_VI] = 32;
151 
152 	if (vap->iv_htcaps & IEEE80211_HTC_HT) {
153 		/*
154 		 * Device is HT capable; enable all HT-related
155 		 * facilities by default.
156 		 * XXX these choices may be too aggressive.
157 		 */
158 		vap->iv_flags_ext |= IEEE80211_FEXT_HT
159 				  |  IEEE80211_FEXT_HTCOMPAT
160 				  ;
161 		if (vap->iv_htcaps & IEEE80211_HTCAP_SHORTGI20)
162 			vap->iv_flags_ext |= IEEE80211_FEXT_SHORTGI20;
163 		/* XXX infer from channel list? */
164 		if (vap->iv_htcaps & IEEE80211_HTCAP_CHWIDTH40) {
165 			vap->iv_flags_ext |= IEEE80211_FEXT_USEHT40;
166 			if (vap->iv_htcaps & IEEE80211_HTCAP_SHORTGI40)
167 				vap->iv_flags_ext |= IEEE80211_FEXT_SHORTGI40;
168 		}
169 		/* NB: A-MPDU and A-MSDU rx are mandated, these are tx only */
170 		vap->iv_flags_ext |= IEEE80211_FEXT_AMPDU_RX;
171 		if (vap->iv_htcaps & IEEE80211_HTC_AMPDU)
172 			vap->iv_flags_ext |= IEEE80211_FEXT_AMPDU_TX;
173 		vap->iv_flags_ext |= IEEE80211_FEXT_AMSDU_RX;
174 		if (vap->iv_htcaps & IEEE80211_HTC_AMSDU)
175 			vap->iv_flags_ext |= IEEE80211_FEXT_AMSDU_TX;
176 	}
177 	/* NB: disable default legacy WDS, too many issues right now */
178 	if (vap->iv_flags_ext & IEEE80211_FEXT_WDSLEGACY)
179 		vap->iv_flags_ext &= ~IEEE80211_FEXT_HT;
180 }
181 
182 void
183 ieee80211_ht_vdetach(struct ieee80211vap *vap)
184 {
185 }
186 
187 static void
188 ht_announce(struct ieee80211com *ic, int mode,
189 	const struct ieee80211_htrateset *rs)
190 {
191 	struct ifnet *ifp = ic->ic_ifp;
192 	int i, rate, mword;
193 
194 	if_printf(ifp, "%s MCS: ", ieee80211_phymode_name[mode]);
195 	for (i = 0; i < rs->rs_nrates; i++) {
196 		mword = ieee80211_rate2media(ic,
197 		    rs->rs_rates[i] | IEEE80211_RATE_MCS, mode);
198 		if (IFM_SUBTYPE(mword) != IFM_IEEE80211_MCS)
199 			continue;
200 		rate = ieee80211_htrates[rs->rs_rates[i]].ht40_rate_400ns;
201 		printf("%s%d%sMbps", (i != 0 ? " " : ""),
202 		    rate / 2, ((rate & 0x1) != 0 ? ".5" : ""));
203 	}
204 	printf("\n");
205 }
206 
207 void
208 ieee80211_ht_announce(struct ieee80211com *ic)
209 {
210 	if (isset(ic->ic_modecaps, IEEE80211_MODE_11NA))
211 		ht_announce(ic, IEEE80211_MODE_11NA, &ieee80211_rateset_11n);
212 	if (isset(ic->ic_modecaps, IEEE80211_MODE_11NG))
213 		ht_announce(ic, IEEE80211_MODE_11NG, &ieee80211_rateset_11n);
214 }
215 
216 const struct ieee80211_htrateset *
217 ieee80211_get_suphtrates(struct ieee80211com *ic,
218 	const struct ieee80211_channel *c)
219 {
220 	return &ieee80211_rateset_11n;
221 }
222 
223 /*
224  * Receive processing.
225  */
226 
227 /*
228  * Decap the encapsulated A-MSDU frames and dispatch all but
229  * the last for delivery.  The last frame is returned for
230  * delivery via the normal path.
231  */
232 struct mbuf *
233 ieee80211_decap_amsdu(struct ieee80211_node *ni, struct mbuf *m)
234 {
235 	struct ieee80211vap *vap = ni->ni_vap;
236 	int framelen;
237 	struct mbuf *n;
238 
239 	/* discard 802.3 header inserted by ieee80211_decap */
240 	m_adj(m, sizeof(struct ether_header));
241 
242 	vap->iv_stats.is_amsdu_decap++;
243 
244 	for (;;) {
245 		/*
246 		 * Decap the first frame, bust it apart from the
247 		 * remainder and deliver.  We leave the last frame
248 		 * delivery to the caller (for consistency with other
249 		 * code paths, could also do it here).
250 		 */
251 		m = ieee80211_decap1(m, &framelen);
252 		if (m == NULL) {
253 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
254 			    ni->ni_macaddr, "a-msdu", "%s", "decap failed");
255 			vap->iv_stats.is_amsdu_tooshort++;
256 			return NULL;
257 		}
258 		if (m->m_pkthdr.len == framelen)
259 			break;
260 		n = m_split(m, framelen, M_NOWAIT);
261 		if (n == NULL) {
262 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
263 			    ni->ni_macaddr, "a-msdu",
264 			    "%s", "unable to split encapsulated frames");
265 			vap->iv_stats.is_amsdu_split++;
266 			m_freem(m);			/* NB: must reclaim */
267 			return NULL;
268 		}
269 		vap->iv_deliver_data(vap, ni, m);
270 
271 		/*
272 		 * Remove frame contents; each intermediate frame
273 		 * is required to be aligned to a 4-byte boundary.
274 		 */
275 		m = n;
276 		m_adj(m, roundup2(framelen, 4) - framelen);	/* padding */
277 	}
278 	return m;				/* last delivered by caller */
279 }
280 
281 /*
282  * Purge all frames in the A-MPDU re-order queue.
283  */
284 static void
285 ampdu_rx_purge(struct ieee80211_rx_ampdu *rap)
286 {
287 	struct mbuf *m;
288 	int i;
289 
290 	for (i = 0; i < rap->rxa_wnd; i++) {
291 		m = rap->rxa_m[i];
292 		if (m != NULL) {
293 			rap->rxa_m[i] = NULL;
294 			rap->rxa_qbytes -= m->m_pkthdr.len;
295 			m_freem(m);
296 			if (--rap->rxa_qframes == 0)
297 				break;
298 		}
299 	}
300 	KASSERT(rap->rxa_qbytes == 0 && rap->rxa_qframes == 0,
301 	    ("lost %u data, %u frames on ampdu rx q",
302 	    rap->rxa_qbytes, rap->rxa_qframes));
303 }
304 
305 /*
306  * Start A-MPDU rx/re-order processing for the specified TID.
307  */
308 static void
309 ampdu_rx_start(struct ieee80211_rx_ampdu *rap, int bufsiz, int start)
310 {
311 	if (rap->rxa_flags & IEEE80211_AGGR_RUNNING) {
312 		/*
313 		 * AMPDU previously setup and not terminated with a DELBA,
314 		 * flush the reorder q's in case anything remains.
315 		 */
316 		ampdu_rx_purge(rap);
317 	}
318 	memset(rap, 0, sizeof(*rap));
319 	rap->rxa_wnd = (bufsiz == 0) ?
320 	    IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
321 	rap->rxa_start = start;
322 	rap->rxa_flags |=  IEEE80211_AGGR_RUNNING | IEEE80211_AGGR_XCHGPEND;
323 }
324 
325 /*
326  * Stop A-MPDU rx processing for the specified TID.
327  */
328 static void
329 ampdu_rx_stop(struct ieee80211_rx_ampdu *rap)
330 {
331 	ampdu_rx_purge(rap);
332 	rap->rxa_flags &= ~(IEEE80211_AGGR_RUNNING | IEEE80211_AGGR_XCHGPEND);
333 }
334 
335 /*
336  * Dispatch a frame from the A-MPDU reorder queue.  The
337  * frame is fed back into ieee80211_input marked with an
338  * M_AMPDU flag so it doesn't come back to us (it also
339  * permits ieee80211_input to optimize re-processing).
340  */
341 static __inline void
342 ampdu_dispatch(struct ieee80211_node *ni, struct mbuf *m)
343 {
344 	m->m_flags |= M_AMPDU;	/* bypass normal processing */
345 	/* NB: rssi, noise, and rstamp are ignored w/ M_AMPDU set */
346 	(void) ieee80211_input(ni, m, 0, 0, 0);
347 }
348 
349 /*
350  * Dispatch as many frames as possible from the re-order queue.
351  * Frames will always be "at the front"; we process all frames
352  * up to the first empty slot in the window.  On completion we
353  * cleanup state if there are still pending frames in the current
354  * BA window.  We assume the frame at slot 0 is already handled
355  * by the caller; we always start at slot 1.
356  */
357 static void
358 ampdu_rx_dispatch(struct ieee80211_rx_ampdu *rap, struct ieee80211_node *ni)
359 {
360 	struct ieee80211vap *vap = ni->ni_vap;
361 	struct mbuf *m;
362 	int i;
363 
364 	/* flush run of frames */
365 	for (i = 1; i < rap->rxa_wnd; i++) {
366 		m = rap->rxa_m[i];
367 		if (m == NULL)
368 			break;
369 		rap->rxa_m[i] = NULL;
370 		rap->rxa_qbytes -= m->m_pkthdr.len;
371 		rap->rxa_qframes--;
372 
373 		ampdu_dispatch(ni, m);
374 	}
375 	/*
376 	 * If frames remain, copy the mbuf pointers down so
377 	 * they correspond to the offsets in the new window.
378 	 */
379 	if (rap->rxa_qframes != 0) {
380 		int n = rap->rxa_qframes, j;
381 		for (j = i+1; j < rap->rxa_wnd; j++) {
382 			if (rap->rxa_m[j] != NULL) {
383 				rap->rxa_m[j-i] = rap->rxa_m[j];
384 				rap->rxa_m[j] = NULL;
385 				if (--n == 0)
386 					break;
387 			}
388 		}
389 		KASSERT(n == 0, ("lost %d frames", n));
390 		vap->iv_stats.is_ampdu_rx_copy += rap->rxa_qframes;
391 	}
392 	/*
393 	 * Adjust the start of the BA window to
394 	 * reflect the frames just dispatched.
395 	 */
396 	rap->rxa_start = IEEE80211_SEQ_ADD(rap->rxa_start, i);
397 	vap->iv_stats.is_ampdu_rx_oor += i;
398 }
399 
400 #ifdef IEEE80211_AMPDU_AGE
401 /*
402  * Dispatch all frames in the A-MPDU re-order queue.
403  */
404 static void
405 ampdu_rx_flush(struct ieee80211_node *ni, struct ieee80211_rx_ampdu *rap)
406 {
407 	struct ieee80211vap *vap = ni->ni_vap;
408 	struct mbuf *m;
409 	int i;
410 
411 	for (i = 0; i < rap->rxa_wnd; i++) {
412 		m = rap->rxa_m[i];
413 		if (m == NULL)
414 			continue;
415 		rap->rxa_m[i] = NULL;
416 		rap->rxa_qbytes -= m->m_pkthdr.len;
417 		rap->rxa_qframes--;
418 		vap->iv_stats.is_ampdu_rx_oor++;
419 
420 		ampdu_dispatch(ni, m);
421 		if (rap->rxa_qframes == 0)
422 			break;
423 	}
424 }
425 #endif /* IEEE80211_AMPDU_AGE */
426 
427 /*
428  * Dispatch all frames in the A-MPDU re-order queue
429  * preceding the specified sequence number.  This logic
430  * handles window moves due to a received MSDU or BAR.
431  */
432 static void
433 ampdu_rx_flush_upto(struct ieee80211_node *ni,
434 	struct ieee80211_rx_ampdu *rap, ieee80211_seq winstart)
435 {
436 	struct ieee80211vap *vap = ni->ni_vap;
437 	struct mbuf *m;
438 	ieee80211_seq seqno;
439 	int i;
440 
441 	/*
442 	 * Flush any complete MSDU's with a sequence number lower
443 	 * than winstart.  Gaps may exist.  Note that we may actually
444 	 * dispatch frames past winstart if a run continues; this is
445 	 * an optimization that avoids having to do a separate pass
446 	 * to dispatch frames after moving the BA window start.
447 	 */
448 	seqno = rap->rxa_start;
449 	for (i = 0; i < rap->rxa_wnd; i++) {
450 		m = rap->rxa_m[i];
451 		if (m != NULL) {
452 			rap->rxa_m[i] = NULL;
453 			rap->rxa_qbytes -= m->m_pkthdr.len;
454 			rap->rxa_qframes--;
455 			vap->iv_stats.is_ampdu_rx_oor++;
456 
457 			ampdu_dispatch(ni, m);
458 		} else {
459 			if (!IEEE80211_SEQ_BA_BEFORE(seqno, winstart))
460 				break;
461 		}
462 		seqno = IEEE80211_SEQ_INC(seqno);
463 	}
464 	/*
465 	 * If frames remain, copy the mbuf pointers down so
466 	 * they correspond to the offsets in the new window.
467 	 */
468 	if (rap->rxa_qframes != 0) {
469 		int n = rap->rxa_qframes, j;
470 
471 		/* NB: this loop assumes i > 0 and/or rxa_m[0] is NULL */
472 		KASSERT(rap->rxa_m[0] == NULL,
473 		    ("%s: BA window slot 0 occupied", __func__));
474 		for (j = i+1; j < rap->rxa_wnd; j++) {
475 			if (rap->rxa_m[j] != NULL) {
476 				rap->rxa_m[j-i] = rap->rxa_m[j];
477 				rap->rxa_m[j] = NULL;
478 				if (--n == 0)
479 					break;
480 			}
481 		}
482 		KASSERT(n == 0, ("%s: lost %d frames, qframes %d off %d "
483 		    "BA win <%d:%d> winstart %d",
484 		    __func__, n, rap->rxa_qframes, i, rap->rxa_start,
485 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
486 		    winstart));
487 		vap->iv_stats.is_ampdu_rx_copy += rap->rxa_qframes;
488 	}
489 	/*
490 	 * Move the start of the BA window; we use the
491 	 * sequence number of the last MSDU that was
492 	 * passed up the stack+1 or winstart if stopped on
493 	 * a gap in the reorder buffer.
494 	 */
495 	rap->rxa_start = seqno;
496 }
497 
498 /*
499  * Process a received QoS data frame for an HT station.  Handle
500  * A-MPDU reordering: if this frame is received out of order
501  * and falls within the BA window hold onto it.  Otherwise if
502  * this frame completes a run, flush any pending frames.  We
503  * return 1 if the frame is consumed.  A 0 is returned if
504  * the frame should be processed normally by the caller.
505  */
506 int
507 ieee80211_ampdu_reorder(struct ieee80211_node *ni, struct mbuf *m)
508 {
509 #define	IEEE80211_FC0_QOSDATA \
510 	(IEEE80211_FC0_TYPE_DATA|IEEE80211_FC0_SUBTYPE_QOS|IEEE80211_FC0_VERSION_0)
511 #define	PROCESS		0	/* caller should process frame */
512 #define	CONSUMED	1	/* frame consumed, caller does nothing */
513 	struct ieee80211vap *vap = ni->ni_vap;
514 	struct ieee80211_qosframe *wh;
515 	struct ieee80211_rx_ampdu *rap;
516 	ieee80211_seq rxseq;
517 	uint8_t tid;
518 	int off;
519 
520 	KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT sta"));
521 
522 	/* NB: m_len known to be sufficient */
523 	wh = mtod(m, struct ieee80211_qosframe *);
524 	KASSERT(wh->i_fc[0] == IEEE80211_FC0_QOSDATA, ("not QoS data"));
525 
526 	if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) == IEEE80211_FC1_DIR_DSTODS)
527 		tid = ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0];
528 	else
529 		tid = wh->i_qos[0];
530 	tid &= IEEE80211_QOS_TID;
531 	rap = &ni->ni_rx_ampdu[tid];
532 	if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
533 		/*
534 		 * No ADDBA request yet, don't touch.
535 		 */
536 		return PROCESS;
537 	}
538 	rxseq = le16toh(*(uint16_t *)wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
539 	rap->rxa_nframes++;
540 again:
541 	if (rxseq == rap->rxa_start) {
542 		/*
543 		 * First frame in window.
544 		 */
545 		if (rap->rxa_qframes != 0) {
546 			/*
547 			 * Dispatch as many packets as we can.
548 			 */
549 			KASSERT(rap->rxa_m[0] == NULL, ("unexpected dup"));
550 			ampdu_dispatch(ni, m);
551 			ampdu_rx_dispatch(rap, ni);
552 			return CONSUMED;
553 		} else {
554 			/*
555 			 * In order; advance window and notify
556 			 * caller to dispatch directly.
557 			 */
558 			rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
559 			return PROCESS;
560 		}
561 	}
562 	/*
563 	 * Frame is out of order; store if in the BA window.
564 	 */
565 	/* calculate offset in BA window */
566 	off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
567 	if (off < rap->rxa_wnd) {
568 		/*
569 		 * Common case (hopefully): in the BA window.
570 		 * Sec 9.10.7.6 a) (D2.04 p.118 line 47)
571 		 */
572 #ifdef IEEE80211_AMPDU_AGE
573 		/*
574 		 * Check for frames sitting too long in the reorder queue.
575 		 * This should only ever happen if frames are not delivered
576 		 * without the sender otherwise notifying us (e.g. with a
577 		 * BAR to move the window).  Typically this happens because
578 		 * of vendor bugs that cause the sequence number to jump.
579 		 * When this happens we get a gap in the reorder queue that
580 		 * leaves frame sitting on the queue until they get pushed
581 		 * out due to window moves.  When the vendor does not send
582 		 * BAR this move only happens due to explicit packet sends
583 		 *
584 		 * NB: we only track the time of the oldest frame in the
585 		 * reorder q; this means that if we flush we might push
586 		 * frames that still "new"; if this happens then subsequent
587 		 * frames will result in BA window moves which cost something
588 		 * but is still better than a big throughput dip.
589 		 */
590 		if (rap->rxa_qframes != 0) {
591 			/* XXX honor batimeout? */
592 			if (ticks - rap->rxa_age > ieee80211_ampdu_age) {
593 				/*
594 				 * Too long since we received the first
595 				 * frame; flush the reorder buffer.
596 				 */
597 				if (rap->rxa_qframes != 0) {
598 					vap->iv_stats.is_ampdu_rx_age +=
599 					    rap->rxa_qframes;
600 					ampdu_rx_flush(ni, rap);
601 				}
602 				rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
603 				return PROCESS;
604 			}
605 		} else {
606 			/*
607 			 * First frame, start aging timer.
608 			 */
609 			rap->rxa_age = ticks;
610 		}
611 #endif /* IEEE80211_AMPDU_AGE */
612 		/* save packet */
613 		if (rap->rxa_m[off] == NULL) {
614 			rap->rxa_m[off] = m;
615 			rap->rxa_qframes++;
616 			rap->rxa_qbytes += m->m_pkthdr.len;
617 			vap->iv_stats.is_ampdu_rx_reorder++;
618 		} else {
619 			IEEE80211_DISCARD_MAC(vap,
620 			    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N,
621 			    ni->ni_macaddr, "a-mpdu duplicate",
622 			    "seqno %u tid %u BA win <%u:%u>",
623 			    rxseq, tid, rap->rxa_start,
624 			    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1));
625 			vap->iv_stats.is_rx_dup++;
626 			IEEE80211_NODE_STAT(ni, rx_dup);
627 			m_freem(m);
628 		}
629 		return CONSUMED;
630 	}
631 	if (off < IEEE80211_SEQ_BA_RANGE) {
632 		/*
633 		 * Outside the BA window, but within range;
634 		 * flush the reorder q and move the window.
635 		 * Sec 9.10.7.6 b) (D2.04 p.118 line 60)
636 		 */
637 		IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
638 		    "move BA win <%u:%u> (%u frames) rxseq %u tid %u",
639 		    rap->rxa_start,
640 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
641 		    rap->rxa_qframes, rxseq, tid);
642 		vap->iv_stats.is_ampdu_rx_move++;
643 
644 		/*
645 		 * The spec says to flush frames up to but not including:
646 		 * 	WinStart_B = rxseq - rap->rxa_wnd + 1
647 		 * Then insert the frame or notify the caller to process
648 		 * it immediately.  We can safely do this by just starting
649 		 * over again because we know the frame will now be within
650 		 * the BA window.
651 		 */
652 		/* NB: rxa_wnd known to be >0 */
653 		ampdu_rx_flush_upto(ni, rap,
654 		    IEEE80211_SEQ_SUB(rxseq, rap->rxa_wnd-1));
655 		goto again;
656 	} else {
657 		/*
658 		 * Outside the BA window and out of range; toss.
659 		 * Sec 9.10.7.6 c) (D2.04 p.119 line 16)
660 		 */
661 		IEEE80211_DISCARD_MAC(vap,
662 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
663 		    "MPDU", "BA win <%u:%u> (%u frames) rxseq %u tid %u%s",
664 		    rap->rxa_start,
665 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
666 		    rap->rxa_qframes, rxseq, tid,
667 		    wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
668 		vap->iv_stats.is_ampdu_rx_drop++;
669 		IEEE80211_NODE_STAT(ni, rx_drop);
670 		m_freem(m);
671 		return CONSUMED;
672 	}
673 #undef CONSUMED
674 #undef PROCESS
675 #undef IEEE80211_FC0_QOSDATA
676 }
677 
678 /*
679  * Process a BAR ctl frame.  Dispatch all frames up to
680  * the sequence number of the frame.  If this frame is
681  * out of range it's discarded.
682  */
683 void
684 ieee80211_recv_bar(struct ieee80211_node *ni, struct mbuf *m0)
685 {
686 	struct ieee80211vap *vap = ni->ni_vap;
687 	struct ieee80211_frame_bar *wh;
688 	struct ieee80211_rx_ampdu *rap;
689 	ieee80211_seq rxseq;
690 	int tid, off;
691 
692 	if (!ieee80211_recv_bar_ena) {
693 #if 0
694 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_11N,
695 		    ni->ni_macaddr, "BAR", "%s", "processing disabled");
696 #endif
697 		vap->iv_stats.is_ampdu_bar_bad++;
698 		return;
699 	}
700 	wh = mtod(m0, struct ieee80211_frame_bar *);
701 	/* XXX check basic BAR */
702 	tid = MS(le16toh(wh->i_ctl), IEEE80211_BAR_TID);
703 	rap = &ni->ni_rx_ampdu[tid];
704 	if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
705 		/*
706 		 * No ADDBA request yet, don't touch.
707 		 */
708 		IEEE80211_DISCARD_MAC(vap,
709 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N,
710 		    ni->ni_macaddr, "BAR", "no BA stream, tid %u", tid);
711 		vap->iv_stats.is_ampdu_bar_bad++;
712 		return;
713 	}
714 	vap->iv_stats.is_ampdu_bar_rx++;
715 	rxseq = le16toh(wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
716 	if (rxseq == rap->rxa_start)
717 		return;
718 	/* calculate offset in BA window */
719 	off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
720 	if (off < IEEE80211_SEQ_BA_RANGE) {
721 		/*
722 		 * Flush the reorder q up to rxseq and move the window.
723 		 * Sec 9.10.7.6 a) (D2.04 p.119 line 22)
724 		 */
725 		IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
726 		    "BAR moves BA win <%u:%u> (%u frames) rxseq %u tid %u",
727 		    rap->rxa_start,
728 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
729 		    rap->rxa_qframes, rxseq, tid);
730 		vap->iv_stats.is_ampdu_bar_move++;
731 
732 		ampdu_rx_flush_upto(ni, rap, rxseq);
733 		if (off >= rap->rxa_wnd) {
734 			/*
735 			 * BAR specifies a window start to the right of BA
736 			 * window; we must move it explicitly since
737 			 * ampdu_rx_flush_upto will not.
738 			 */
739 			rap->rxa_start = rxseq;
740 		}
741 	} else {
742 		/*
743 		 * Out of range; toss.
744 		 * Sec 9.10.7.6 b) (D2.04 p.119 line 41)
745 		 */
746 		IEEE80211_DISCARD_MAC(vap,
747 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
748 		    "BAR", "BA win <%u:%u> (%u frames) rxseq %u tid %u%s",
749 		    rap->rxa_start,
750 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
751 		    rap->rxa_qframes, rxseq, tid,
752 		    wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
753 		vap->iv_stats.is_ampdu_bar_oow++;
754 		IEEE80211_NODE_STAT(ni, rx_drop);
755 	}
756 }
757 
758 /*
759  * Setup HT-specific state in a node.  Called only
760  * when HT use is negotiated so we don't do extra
761  * work for temporary and/or legacy sta's.
762  */
763 void
764 ieee80211_ht_node_init(struct ieee80211_node *ni, const uint8_t *htcap)
765 {
766 	struct ieee80211_tx_ampdu *tap;
767 	int ac;
768 
769 	if (ni->ni_flags & IEEE80211_NODE_HT) {
770 		/*
771 		 * Clean AMPDU state on re-associate.  This handles the case
772 		 * where a station leaves w/o notifying us and then returns
773 		 * before node is reaped for inactivity.
774 		 */
775 		ieee80211_ht_node_cleanup(ni);
776 	}
777 	ieee80211_parse_htcap(ni, htcap);
778 	for (ac = 0; ac < WME_NUM_AC; ac++) {
779 		tap = &ni->ni_tx_ampdu[ac];
780 		tap->txa_ac = ac;
781 		/* NB: further initialization deferred */
782 	}
783 	ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
784 }
785 
786 /*
787  * Cleanup HT-specific state in a node.  Called only
788  * when HT use has been marked.
789  */
790 void
791 ieee80211_ht_node_cleanup(struct ieee80211_node *ni)
792 {
793 	struct ieee80211com *ic = ni->ni_ic;
794 	int i;
795 
796 	KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT node"));
797 
798 	/* XXX optimize this */
799 	for (i = 0; i < WME_NUM_AC; i++) {
800 		struct ieee80211_tx_ampdu *tap = &ni->ni_tx_ampdu[i];
801 		if (tap->txa_flags & IEEE80211_AGGR_SETUP) {
802 			/*
803 			 * Stop BA stream if setup so driver has a chance
804 			 * to reclaim any resources it might have allocated.
805 			 */
806 			ic->ic_addba_stop(ni, &ni->ni_tx_ampdu[i]);
807 			IEEE80211_TAPQ_DESTROY(tap);
808 			tap->txa_lastsample = 0;
809 			tap->txa_avgpps = 0;
810 			/* NB: clearing NAK means we may re-send ADDBA */
811 			tap->txa_flags &=
812 			    ~(IEEE80211_AGGR_SETUP | IEEE80211_AGGR_NAK);
813 		}
814 	}
815 	for (i = 0; i < WME_NUM_TID; i++)
816 		ampdu_rx_stop(&ni->ni_rx_ampdu[i]);
817 
818 	ni->ni_htcap = 0;
819 	ni->ni_flags &= ~(IEEE80211_NODE_HT | IEEE80211_NODE_HTCOMPAT |
820 		IEEE80211_NODE_AMPDU);
821 }
822 
823 /*
824  * Age out HT resources for a station.
825  */
826 void
827 ieee80211_ht_node_age(struct ieee80211_node *ni)
828 {
829 #ifdef IEEE80211_AMPDU_AGE
830 	struct ieee80211vap *vap = ni->ni_vap;
831 	uint8_t tid;
832 #endif
833 
834 	KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT sta"));
835 
836 #ifdef IEEE80211_AMPDU_AGE
837 	for (tid = 0; tid < WME_NUM_TID; tid++) {
838 		struct ieee80211_rx_ampdu *rap;
839 
840 		rap = &ni->ni_rx_ampdu[tid];
841 		if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0)
842 			continue;
843 		if (rap->rxa_qframes == 0)
844 			continue;
845 		/*
846 		 * Check for frames sitting too long in the reorder queue.
847 		 * See above for more details on what's happening here.
848 		 */
849 		/* XXX honor batimeout? */
850 		if (ticks - rap->rxa_age > ieee80211_ampdu_age) {
851 			/*
852 			 * Too long since we received the first
853 			 * frame; flush the reorder buffer.
854 			 */
855 			vap->iv_stats.is_ampdu_rx_age += rap->rxa_qframes;
856 			ampdu_rx_flush(ni, rap);
857 		}
858 	}
859 #endif /* IEEE80211_AMPDU_AGE */
860 }
861 
862 static struct ieee80211_channel *
863 findhtchan(struct ieee80211com *ic, struct ieee80211_channel *c, int htflags)
864 {
865 	return ieee80211_find_channel(ic, c->ic_freq,
866 	    (c->ic_flags &~ IEEE80211_CHAN_HT) | htflags);
867 }
868 
869 /*
870  * Adjust a channel to be HT/non-HT according to the vap's configuration.
871  */
872 struct ieee80211_channel *
873 ieee80211_ht_adjust_channel(struct ieee80211com *ic,
874 	struct ieee80211_channel *chan, int flags)
875 {
876 	struct ieee80211_channel *c;
877 
878 	if (flags & IEEE80211_FEXT_HT) {
879 		/* promote to HT if possible */
880 		if (flags & IEEE80211_FEXT_USEHT40) {
881 			if (!IEEE80211_IS_CHAN_HT40(chan)) {
882 				/* NB: arbitrarily pick ht40+ over ht40- */
883 				c = findhtchan(ic, chan, IEEE80211_CHAN_HT40U);
884 				if (c == NULL)
885 					c = findhtchan(ic, chan,
886 						IEEE80211_CHAN_HT40D);
887 				if (c == NULL)
888 					c = findhtchan(ic, chan,
889 						IEEE80211_CHAN_HT20);
890 				if (c != NULL)
891 					chan = c;
892 			}
893 		} else if (!IEEE80211_IS_CHAN_HT20(chan)) {
894 			c = findhtchan(ic, chan, IEEE80211_CHAN_HT20);
895 			if (c != NULL)
896 				chan = c;
897 		}
898 	} else if (IEEE80211_IS_CHAN_HT(chan)) {
899 		/* demote to legacy, HT use is disabled */
900 		c = ieee80211_find_channel(ic, chan->ic_freq,
901 		    chan->ic_flags &~ IEEE80211_CHAN_HT);
902 		if (c != NULL)
903 			chan = c;
904 	}
905 	return chan;
906 }
907 
908 /*
909  * Setup HT-specific state for a legacy WDS peer.
910  */
911 void
912 ieee80211_ht_wds_init(struct ieee80211_node *ni)
913 {
914 	struct ieee80211vap *vap = ni->ni_vap;
915 	struct ieee80211_tx_ampdu *tap;
916 	int ac;
917 
918 	KASSERT(vap->iv_flags_ext & IEEE80211_FEXT_HT, ("no HT requested"));
919 
920 	/* XXX check scan cache in case peer has an ap and we have info */
921 	/*
922 	 * If setup with a legacy channel; locate an HT channel.
923 	 * Otherwise if the inherited channel (from a companion
924 	 * AP) is suitable use it so we use the same location
925 	 * for the extension channel).
926 	 */
927 	ni->ni_chan = ieee80211_ht_adjust_channel(ni->ni_ic,
928 	    ni->ni_chan, ieee80211_htchanflags(ni->ni_chan));
929 
930 	ni->ni_htcap = 0;
931 	if (vap->iv_flags_ext & IEEE80211_FEXT_SHORTGI20)
932 		ni->ni_htcap |= IEEE80211_HTCAP_SHORTGI20;
933 	if (IEEE80211_IS_CHAN_HT40(ni->ni_chan)) {
934 		ni->ni_htcap |= IEEE80211_HTCAP_CHWIDTH40;
935 		ni->ni_chw = 40;
936 		if (IEEE80211_IS_CHAN_HT40U(ni->ni_chan))
937 			ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_ABOVE;
938 		else if (IEEE80211_IS_CHAN_HT40D(ni->ni_chan))
939 			ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_BELOW;
940 		if (vap->iv_flags_ext & IEEE80211_FEXT_SHORTGI40)
941 			ni->ni_htcap |= IEEE80211_HTCAP_SHORTGI40;
942 	} else {
943 		ni->ni_chw = 20;
944 		ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_NONE;
945 	}
946 	ni->ni_htctlchan = ni->ni_chan->ic_ieee;
947 
948 	ni->ni_htopmode = 0;		/* XXX need protection state */
949 	ni->ni_htstbc = 0;		/* XXX need info */
950 
951 	for (ac = 0; ac < WME_NUM_AC; ac++) {
952 		tap = &ni->ni_tx_ampdu[ac];
953 		tap->txa_ac = ac;
954 	}
955 	/* NB: AMPDU tx/rx governed by IEEE80211_FEXT_AMPDU_{TX,RX} */
956 	ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
957 }
958 
959 /*
960  * Notify hostap vaps of a change in the HTINFO ie.
961  */
962 static void
963 htinfo_notify(struct ieee80211com *ic)
964 {
965 	struct ieee80211vap *vap;
966 	int first = 1;
967 
968 	IEEE80211_LOCK_ASSERT(ic);
969 
970 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
971 		if (vap->iv_opmode != IEEE80211_M_HOSTAP)
972 			continue;
973 		if (first) {
974 			IEEE80211_NOTE(vap,
975 			    IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N,
976 			    vap->iv_bss,
977 			    "HT bss occupancy change: %d sta, %d ht, "
978 			    "%d ht40%s, HT protmode now 0x%x"
979 			    , ic->ic_sta_assoc
980 			    , ic->ic_ht_sta_assoc
981 			    , ic->ic_ht40_sta_assoc
982 			    , (ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) ?
983 				 ", non-HT sta present" : ""
984 			    , ic->ic_curhtprotmode);
985 			first = 0;
986 		}
987 		ieee80211_beacon_notify(vap, IEEE80211_BEACON_HTINFO);
988 	}
989 }
990 
991 /*
992  * Calculate HT protection mode from current
993  * state and handle updates.
994  */
995 static void
996 htinfo_update(struct ieee80211com *ic)
997 {
998 	uint8_t protmode;
999 
1000 	if (ic->ic_sta_assoc != ic->ic_ht_sta_assoc) {
1001 		protmode = IEEE80211_HTINFO_OPMODE_MIXED
1002 			 | IEEE80211_HTINFO_NONHT_PRESENT;
1003 	} else if (ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) {
1004 		protmode = IEEE80211_HTINFO_OPMODE_PROTOPT
1005 			 | IEEE80211_HTINFO_NONHT_PRESENT;
1006 	} else if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
1007 	    IEEE80211_IS_CHAN_HT40(ic->ic_bsschan) &&
1008 	    ic->ic_sta_assoc != ic->ic_ht40_sta_assoc) {
1009 		protmode = IEEE80211_HTINFO_OPMODE_HT20PR;
1010 	} else {
1011 		protmode = IEEE80211_HTINFO_OPMODE_PURE;
1012 	}
1013 	if (protmode != ic->ic_curhtprotmode) {
1014 		ic->ic_curhtprotmode = protmode;
1015 		htinfo_notify(ic);
1016 	}
1017 }
1018 
1019 /*
1020  * Handle an HT station joining a BSS.
1021  */
1022 void
1023 ieee80211_ht_node_join(struct ieee80211_node *ni)
1024 {
1025 	struct ieee80211com *ic = ni->ni_ic;
1026 
1027 	IEEE80211_LOCK_ASSERT(ic);
1028 
1029 	if (ni->ni_flags & IEEE80211_NODE_HT) {
1030 		ic->ic_ht_sta_assoc++;
1031 		if (ni->ni_chw == 40)
1032 			ic->ic_ht40_sta_assoc++;
1033 	}
1034 	htinfo_update(ic);
1035 }
1036 
1037 /*
1038  * Handle an HT station leaving a BSS.
1039  */
1040 void
1041 ieee80211_ht_node_leave(struct ieee80211_node *ni)
1042 {
1043 	struct ieee80211com *ic = ni->ni_ic;
1044 
1045 	IEEE80211_LOCK_ASSERT(ic);
1046 
1047 	if (ni->ni_flags & IEEE80211_NODE_HT) {
1048 		ic->ic_ht_sta_assoc--;
1049 		if (ni->ni_chw == 40)
1050 			ic->ic_ht40_sta_assoc--;
1051 	}
1052 	htinfo_update(ic);
1053 }
1054 
1055 /*
1056  * Public version of htinfo_update; used for processing
1057  * beacon frames from overlapping bss.
1058  *
1059  * Caller can specify either IEEE80211_HTINFO_OPMODE_MIXED
1060  * (on receipt of a beacon that advertises MIXED) or
1061  * IEEE80211_HTINFO_OPMODE_PROTOPT (on receipt of a beacon
1062  * from an overlapping legacy bss).  We treat MIXED with
1063  * a higher precedence than PROTOPT (i.e. we will not change
1064  * change PROTOPT -> MIXED; only MIXED -> PROTOPT).  This
1065  * corresponds to how we handle things in htinfo_update.
1066  */
1067 void
1068 ieee80211_htprot_update(struct ieee80211com *ic, int protmode)
1069 {
1070 #define	OPMODE(x)	SM(x, IEEE80211_HTINFO_OPMODE)
1071 	if (protmode == ic->ic_curhtprotmode)
1072 		return;
1073 	if (OPMODE(ic->ic_curhtprotmode) == IEEE80211_HTINFO_OPMODE_MIXED &&
1074 	    OPMODE(protmode) == IEEE80211_HTINFO_OPMODE_PROTOPT)
1075 		return;
1076 
1077 	IEEE80211_LOCK(ic);
1078 	/* track non-HT station presence */
1079 	KASSERT(protmode & IEEE80211_HTINFO_NONHT_PRESENT,
1080 	    ("missing NONHT_PRESENT"));
1081 	ic->ic_flags_ext |= IEEE80211_FEXT_NONHT_PR;
1082 	ic->ic_lastnonht = ticks;
1083 
1084 	/* push beacon update */
1085 	ic->ic_curhtprotmode = protmode;
1086 	htinfo_notify(ic);
1087 	IEEE80211_UNLOCK(ic);
1088 #undef OPMODE
1089 }
1090 
1091 /*
1092  * Time out presence of an overlapping bss with non-HT
1093  * stations.  When operating in hostap mode we listen for
1094  * beacons from other stations and if we identify a non-HT
1095  * station is present we update the opmode field of the
1096  * HTINFO ie.  To identify when all non-HT stations are
1097  * gone we time out this condition.
1098  */
1099 void
1100 ieee80211_ht_timeout(struct ieee80211com *ic)
1101 {
1102 	IEEE80211_LOCK_ASSERT(ic);
1103 
1104 	if ((ic->ic_flags_ext & IEEE80211_FEXT_NONHT_PR) &&
1105 	    time_after(ticks, ic->ic_lastnonht + IEEE80211_NONHT_PRESENT_AGE)) {
1106 #if 0
1107 		IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
1108 		    "%s", "time out non-HT STA present on channel");
1109 #endif
1110 		ic->ic_flags_ext &= ~IEEE80211_FEXT_NONHT_PR;
1111 		htinfo_update(ic);
1112 	}
1113 }
1114 
1115 /* unalligned little endian access */
1116 #define LE_READ_2(p)					\
1117 	((uint16_t)					\
1118 	 ((((const uint8_t *)(p))[0]      ) |		\
1119 	  (((const uint8_t *)(p))[1] <<  8)))
1120 
1121 /*
1122  * Process an 802.11n HT capabilities ie.
1123  */
1124 void
1125 ieee80211_parse_htcap(struct ieee80211_node *ni, const uint8_t *ie)
1126 {
1127 	struct ieee80211vap *vap = ni->ni_vap;
1128 
1129 	if (ie[0] == IEEE80211_ELEMID_VENDOR) {
1130 		/*
1131 		 * Station used Vendor OUI ie to associate;
1132 		 * mark the node so when we respond we'll use
1133 		 * the Vendor OUI's and not the standard ie's.
1134 		 */
1135 		ni->ni_flags |= IEEE80211_NODE_HTCOMPAT;
1136 		ie += 4;
1137 	} else
1138 		ni->ni_flags &= ~IEEE80211_NODE_HTCOMPAT;
1139 
1140 	ni->ni_htcap = LE_READ_2(ie +
1141 		__offsetof(struct ieee80211_ie_htcap, hc_cap));
1142 	ni->ni_htparam = ie[__offsetof(struct ieee80211_ie_htcap, hc_param)];
1143 	/* XXX needed or will ieee80211_parse_htinfo always be called? */
1144 	ni->ni_chw = (ni->ni_htcap & IEEE80211_HTCAP_CHWIDTH40) &&
1145 		     (vap->iv_flags_ext & IEEE80211_FEXT_USEHT40) ? 40 : 20;
1146 }
1147 
1148 /*
1149  * Process an 802.11n HT info ie and update the node state.
1150  * Note that we handle use this information to identify the
1151  * correct channel (HT20, HT40+, HT40-, legacy).  The caller
1152  * is responsible for insuring any required channel change is
1153  * done (e.g. in sta mode when parsing the contents of a
1154  * beacon frame).
1155  */
1156 void
1157 ieee80211_parse_htinfo(struct ieee80211_node *ni, const uint8_t *ie)
1158 {
1159 	struct ieee80211com *ic = ni->ni_ic;
1160 	struct ieee80211vap *vap = ni->ni_vap;
1161  	const struct ieee80211_ie_htinfo *htinfo;
1162 	struct ieee80211_channel *c;
1163 	uint16_t w;
1164 	int htflags, chanflags;
1165 
1166 	if (ie[0] == IEEE80211_ELEMID_VENDOR)
1167 		ie += 4;
1168  	htinfo = (const struct ieee80211_ie_htinfo *) ie;
1169 	ni->ni_htctlchan = htinfo->hi_ctrlchannel;
1170 	ni->ni_ht2ndchan = SM(htinfo->hi_byte1, IEEE80211_HTINFO_2NDCHAN);
1171 	w = LE_READ_2(&htinfo->hi_byte2);
1172 	ni->ni_htopmode = SM(w, IEEE80211_HTINFO_OPMODE);
1173 	w = LE_READ_2(&htinfo->hi_byte45);
1174 	ni->ni_htstbc = SM(w, IEEE80211_HTINFO_BASIC_STBCMCS);
1175 	/*
1176 	 * Handle 11n channel switch.  Use the received HT ie's to
1177 	 * identify the right channel to use.  If we cannot locate it
1178 	 * in the channel table then fallback to legacy operation.
1179 	 */
1180 	/* NB: honor operating mode constraint */
1181 	htflags = (vap->iv_flags_ext & IEEE80211_FEXT_HT) ?
1182 	    IEEE80211_CHAN_HT20 : 0;
1183 	if ((htinfo->hi_byte1 & IEEE80211_HTINFO_TXWIDTH_2040) &&
1184 	    (vap->iv_flags_ext & IEEE80211_FEXT_USEHT40)) {
1185 		if (ni->ni_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_ABOVE)
1186 			htflags = IEEE80211_CHAN_HT40U;
1187 		else if (ni->ni_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_BELOW)
1188 			htflags = IEEE80211_CHAN_HT40D;
1189 	}
1190 	chanflags = (ni->ni_chan->ic_flags &~ IEEE80211_CHAN_HT) | htflags;
1191 	if (chanflags != ni->ni_chan->ic_flags) {
1192 		c = ieee80211_find_channel(ic, ni->ni_chan->ic_freq, chanflags);
1193 		if (c == NULL && (htflags & IEEE80211_CHAN_HT40)) {
1194 			/*
1195 			 * No HT40 channel entry in our table; fall back
1196 			 * to HT20 operation.  This should not happen.
1197 			 */
1198 			c = findhtchan(ic, ni->ni_chan, IEEE80211_CHAN_HT20);
1199 			IEEE80211_NOTE(vap,
1200 			    IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N, ni,
1201 			    "no HT40 channel (freq %u), falling back to HT20",
1202 			    ni->ni_chan->ic_freq);
1203 			/* XXX stat */
1204 		}
1205 		if (c != NULL && c != ni->ni_chan) {
1206 			IEEE80211_NOTE(vap,
1207 			    IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N, ni,
1208 			    "switch station to HT%d channel %u/0x%x",
1209 			    IEEE80211_IS_CHAN_HT40(c) ? 40 : 20,
1210 			    c->ic_freq, c->ic_flags);
1211 			ni->ni_chan = c;
1212 		}
1213 		/* NB: caller responsible for forcing any channel change */
1214 	}
1215 	/* update node's tx channel width */
1216 	ni->ni_chw = IEEE80211_IS_CHAN_HT40(ni->ni_chan)? 40 : 20;
1217 }
1218 
1219 /*
1220  * Install received HT rate set by parsing the HT cap ie.
1221  */
1222 int
1223 ieee80211_setup_htrates(struct ieee80211_node *ni, const uint8_t *ie, int flags)
1224 {
1225 	struct ieee80211vap *vap = ni->ni_vap;
1226 	const struct ieee80211_ie_htcap *htcap;
1227 	struct ieee80211_htrateset *rs;
1228 	int i;
1229 
1230 	rs = &ni->ni_htrates;
1231 	memset(rs, 0, sizeof(*rs));
1232 	if (ie != NULL) {
1233 		if (ie[0] == IEEE80211_ELEMID_VENDOR)
1234 			ie += 4;
1235 		htcap = (const struct ieee80211_ie_htcap *) ie;
1236 		for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
1237 			if (isclr(htcap->hc_mcsset, i))
1238 				continue;
1239 			if (rs->rs_nrates == IEEE80211_HTRATE_MAXSIZE) {
1240 				IEEE80211_NOTE(vap,
1241 				    IEEE80211_MSG_XRATE | IEEE80211_MSG_11N, ni,
1242 				    "WARNING, HT rate set too large; only "
1243 				    "using %u rates", IEEE80211_HTRATE_MAXSIZE);
1244 				vap->iv_stats.is_rx_rstoobig++;
1245 				break;
1246 			}
1247 			rs->rs_rates[rs->rs_nrates++] = i;
1248 		}
1249 	}
1250 	return ieee80211_fix_rate(ni, (struct ieee80211_rateset *) rs, flags);
1251 }
1252 
1253 /*
1254  * Mark rates in a node's HT rate set as basic according
1255  * to the information in the supplied HT info ie.
1256  */
1257 void
1258 ieee80211_setup_basic_htrates(struct ieee80211_node *ni, const uint8_t *ie)
1259 {
1260 	const struct ieee80211_ie_htinfo *htinfo;
1261 	struct ieee80211_htrateset *rs;
1262 	int i, j;
1263 
1264 	if (ie[0] == IEEE80211_ELEMID_VENDOR)
1265 		ie += 4;
1266 	htinfo = (const struct ieee80211_ie_htinfo *) ie;
1267 	rs = &ni->ni_htrates;
1268 	if (rs->rs_nrates == 0) {
1269 		IEEE80211_NOTE(ni->ni_vap,
1270 		    IEEE80211_MSG_XRATE | IEEE80211_MSG_11N, ni,
1271 		    "%s", "WARNING, empty HT rate set");
1272 		return;
1273 	}
1274 	for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
1275 		if (isclr(htinfo->hi_basicmcsset, i))
1276 			continue;
1277 		for (j = 0; j < rs->rs_nrates; j++)
1278 			if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == i)
1279 				rs->rs_rates[j] |= IEEE80211_RATE_BASIC;
1280 	}
1281 }
1282 
1283 static void
1284 addba_timeout(void *arg)
1285 {
1286 	struct ieee80211_tx_ampdu *tap = arg;
1287 
1288 	/* XXX ? */
1289 	tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
1290 	tap->txa_attempts++;
1291 }
1292 
1293 static void
1294 addba_start_timeout(struct ieee80211_tx_ampdu *tap)
1295 {
1296 	/* XXX use CALLOUT_PENDING instead? */
1297 	callout_reset(&tap->txa_timer, ieee80211_addba_timeout,
1298 	    addba_timeout, tap);
1299 	tap->txa_flags |= IEEE80211_AGGR_XCHGPEND;
1300 	tap->txa_nextrequest = ticks + ieee80211_addba_timeout;
1301 }
1302 
1303 static void
1304 addba_stop_timeout(struct ieee80211_tx_ampdu *tap)
1305 {
1306 	/* XXX use CALLOUT_PENDING instead? */
1307 	if (tap->txa_flags & IEEE80211_AGGR_XCHGPEND) {
1308 		callout_stop(&tap->txa_timer);
1309 		tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
1310 	}
1311 }
1312 
1313 /*
1314  * Default method for requesting A-MPDU tx aggregation.
1315  * We setup the specified state block and start a timer
1316  * to wait for an ADDBA response frame.
1317  */
1318 static int
1319 ieee80211_addba_request(struct ieee80211_node *ni,
1320 	struct ieee80211_tx_ampdu *tap,
1321 	int dialogtoken, int baparamset, int batimeout)
1322 {
1323 	int bufsiz;
1324 
1325 	/* XXX locking */
1326 	tap->txa_token = dialogtoken;
1327 	tap->txa_flags |= IEEE80211_AGGR_IMMEDIATE;
1328 	tap->txa_start = tap->txa_seqstart = 0;
1329 	bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1330 	tap->txa_wnd = (bufsiz == 0) ?
1331 	    IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
1332 	addba_start_timeout(tap);
1333 	return 1;
1334 }
1335 
1336 /*
1337  * Default method for processing an A-MPDU tx aggregation
1338  * response.  We shutdown any pending timer and update the
1339  * state block according to the reply.
1340  */
1341 static int
1342 ieee80211_addba_response(struct ieee80211_node *ni,
1343 	struct ieee80211_tx_ampdu *tap,
1344 	int status, int baparamset, int batimeout)
1345 {
1346 	int bufsiz;
1347 
1348 	/* XXX locking */
1349 	addba_stop_timeout(tap);
1350 	if (status == IEEE80211_STATUS_SUCCESS) {
1351 		bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1352 		/* XXX override our request? */
1353 		tap->txa_wnd = (bufsiz == 0) ?
1354 		    IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
1355 		tap->txa_flags |= IEEE80211_AGGR_RUNNING;
1356 	} else {
1357 		/* mark tid so we don't try again */
1358 		tap->txa_flags |= IEEE80211_AGGR_NAK;
1359 	}
1360 	return 1;
1361 }
1362 
1363 /*
1364  * Default method for stopping A-MPDU tx aggregation.
1365  * Any timer is cleared and we drain any pending frames.
1366  */
1367 static void
1368 ieee80211_addba_stop(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap)
1369 {
1370 	/* XXX locking */
1371 	addba_stop_timeout(tap);
1372 	if (tap->txa_flags & IEEE80211_AGGR_RUNNING) {
1373 		/* clear aggregation queue */
1374 		ieee80211_drain_ifq(&tap->txa_q);
1375 		tap->txa_flags &= ~IEEE80211_AGGR_RUNNING;
1376 	}
1377 	tap->txa_attempts = 0;
1378 }
1379 
1380 /*
1381  * Process a received action frame using the default aggregation
1382  * policy.  We intercept ADDBA-related frames and use them to
1383  * update our aggregation state.  All other frames are passed up
1384  * for processing by ieee80211_recv_action.
1385  */
1386 static void
1387 ieee80211_aggr_recv_action(struct ieee80211_node *ni,
1388 	const uint8_t *frm, const uint8_t *efrm)
1389 {
1390 	struct ieee80211com *ic = ni->ni_ic;
1391 	struct ieee80211vap *vap = ni->ni_vap;
1392 	const struct ieee80211_action *ia;
1393 	struct ieee80211_rx_ampdu *rap;
1394 	struct ieee80211_tx_ampdu *tap;
1395 	uint8_t dialogtoken;
1396 	uint16_t baparamset, batimeout, baseqctl, code;
1397 	uint16_t args[4];
1398 	int tid, ac, bufsiz;
1399 
1400 	ia = (const struct ieee80211_action *) frm;
1401 	switch (ia->ia_category) {
1402 	case IEEE80211_ACTION_CAT_BA:
1403 		switch (ia->ia_action) {
1404 		case IEEE80211_ACTION_BA_ADDBA_REQUEST:
1405 			dialogtoken = frm[2];
1406 			baparamset = LE_READ_2(frm+3);
1407 			batimeout = LE_READ_2(frm+5);
1408 			baseqctl = LE_READ_2(frm+7);
1409 
1410 			tid = MS(baparamset, IEEE80211_BAPS_TID);
1411 			bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1412 
1413 			IEEE80211_NOTE(vap,
1414 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1415 			    "recv ADDBA request: dialogtoken %u "
1416 			    "baparamset 0x%x (tid %d bufsiz %d) batimeout %d "
1417 			    "baseqctl %d:%d",
1418 			    dialogtoken, baparamset, tid, bufsiz, batimeout,
1419 			    MS(baseqctl, IEEE80211_BASEQ_START),
1420 			    MS(baseqctl, IEEE80211_BASEQ_FRAG));
1421 
1422 			rap = &ni->ni_rx_ampdu[tid];
1423 
1424 			/* Send ADDBA response */
1425 			args[0] = dialogtoken;
1426 			/*
1427 			 * NB: We ack only if the sta associated with HT and
1428 			 * the ap is configured to do AMPDU rx (the latter
1429 			 * violates the 11n spec and is mostly for testing).
1430 			 */
1431 			if ((ni->ni_flags & IEEE80211_NODE_AMPDU_RX) &&
1432 			    (vap->iv_flags_ext & IEEE80211_FEXT_AMPDU_RX)) {
1433 				ampdu_rx_start(rap, bufsiz,
1434 				    MS(baseqctl, IEEE80211_BASEQ_START));
1435 
1436 				args[1] = IEEE80211_STATUS_SUCCESS;
1437 			} else {
1438 				IEEE80211_NOTE(vap,
1439 				    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1440 				    ni, "reject ADDBA request: %s",
1441 				    ni->ni_flags & IEEE80211_NODE_AMPDU_RX ?
1442 				       "administratively disabled" :
1443 				       "not negotiated for station");
1444 				vap->iv_stats.is_addba_reject++;
1445 				args[1] = IEEE80211_STATUS_UNSPECIFIED;
1446 			}
1447 			/* XXX honor rap flags? */
1448 			args[2] = IEEE80211_BAPS_POLICY_IMMEDIATE
1449 				| SM(tid, IEEE80211_BAPS_TID)
1450 				| SM(rap->rxa_wnd, IEEE80211_BAPS_BUFSIZ)
1451 				;
1452 			args[3] = 0;
1453 			ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
1454 				IEEE80211_ACTION_BA_ADDBA_RESPONSE, args);
1455 			return;
1456 
1457 		case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
1458 			dialogtoken = frm[2];
1459 			code = LE_READ_2(frm+3);
1460 			baparamset = LE_READ_2(frm+5);
1461 			tid = MS(baparamset, IEEE80211_BAPS_TID);
1462 			bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1463 			batimeout = LE_READ_2(frm+7);
1464 
1465 			ac = TID_TO_WME_AC(tid);
1466 			tap = &ni->ni_tx_ampdu[ac];
1467 			if ((tap->txa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
1468 				IEEE80211_DISCARD_MAC(vap,
1469 				    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1470 				    ni->ni_macaddr, "ADDBA response",
1471 				    "no pending ADDBA, tid %d dialogtoken %u "
1472 				    "code %d", tid, dialogtoken, code);
1473 				vap->iv_stats.is_addba_norequest++;
1474 				return;
1475 			}
1476 			if (dialogtoken != tap->txa_token) {
1477 				IEEE80211_DISCARD_MAC(vap,
1478 				    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1479 				    ni->ni_macaddr, "ADDBA response",
1480 				    "dialogtoken mismatch: waiting for %d, "
1481 				    "received %d, tid %d code %d",
1482 				    tap->txa_token, dialogtoken, tid, code);
1483 				vap->iv_stats.is_addba_badtoken++;
1484 				return;
1485 			}
1486 
1487 			IEEE80211_NOTE(vap,
1488 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1489 			    "recv ADDBA response: dialogtoken %u code %d "
1490 			    "baparamset 0x%x (tid %d bufsiz %d) batimeout %d",
1491 			    dialogtoken, code, baparamset, tid, bufsiz,
1492 			    batimeout);
1493 			ic->ic_addba_response(ni, tap,
1494 				code, baparamset, batimeout);
1495 			return;
1496 
1497 		case IEEE80211_ACTION_BA_DELBA:
1498 			baparamset = LE_READ_2(frm+2);
1499 			code = LE_READ_2(frm+4);
1500 
1501 			tid = MS(baparamset, IEEE80211_DELBAPS_TID);
1502 
1503 			IEEE80211_NOTE(vap,
1504 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1505 			    "recv DELBA: baparamset 0x%x (tid %d initiator %d) "
1506 			    "code %d", baparamset, tid,
1507 			    MS(baparamset, IEEE80211_DELBAPS_INIT), code);
1508 
1509 			if ((baparamset & IEEE80211_DELBAPS_INIT) == 0) {
1510 				ac = TID_TO_WME_AC(tid);
1511 				tap = &ni->ni_tx_ampdu[ac];
1512 				ic->ic_addba_stop(ni, tap);
1513 			} else {
1514 				rap = &ni->ni_rx_ampdu[tid];
1515 				ampdu_rx_stop(rap);
1516 			}
1517 			return;
1518 		}
1519 		break;
1520 	}
1521 	ieee80211_recv_action(ni, frm, efrm);
1522 }
1523 
1524 /*
1525  * Process a received 802.11n action frame.
1526  * Aggregation-related frames are assumed to be handled
1527  * already; we handle any other frames we can, otherwise
1528  * complain about being unsupported (with debugging).
1529  */
1530 void
1531 ieee80211_recv_action(struct ieee80211_node *ni,
1532 	const uint8_t *frm, const uint8_t *efrm)
1533 {
1534 	struct ieee80211vap *vap = ni->ni_vap;
1535 	const struct ieee80211_action *ia;
1536 	int chw;
1537 
1538 	ia = (const struct ieee80211_action *) frm;
1539 	switch (ia->ia_category) {
1540 	case IEEE80211_ACTION_CAT_BA:
1541 		IEEE80211_NOTE(vap,
1542 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1543 		    "%s: BA action %d not implemented", __func__,
1544 		    ia->ia_action);
1545 		vap->iv_stats.is_rx_mgtdiscard++;
1546 		break;
1547 	case IEEE80211_ACTION_CAT_HT:
1548 		switch (ia->ia_action) {
1549 		case IEEE80211_ACTION_HT_TXCHWIDTH:
1550 			chw = frm[2] == IEEE80211_A_HT_TXCHWIDTH_2040 ? 40 : 20;
1551 			if (chw != ni->ni_chw) {
1552 				ni->ni_chw = chw;
1553 				ni->ni_flags |= IEEE80211_NODE_CHWUPDATE;
1554 			}
1555 			IEEE80211_NOTE(vap,
1556 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1557 		            "%s: HT txchwidth, width %d (%s)",
1558 			    __func__, chw,
1559 			    ni->ni_flags & IEEE80211_NODE_CHWUPDATE ?
1560 				"new" : "no change");
1561 			break;
1562 		case IEEE80211_ACTION_HT_MIMOPWRSAVE:
1563 			IEEE80211_NOTE(vap,
1564 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1565 		            "%s: HT MIMO PS", __func__);
1566 			break;
1567 		default:
1568 			IEEE80211_NOTE(vap,
1569 			   IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1570 		           "%s: HT action %d not implemented", __func__,
1571 			   ia->ia_action);
1572 			vap->iv_stats.is_rx_mgtdiscard++;
1573 			break;
1574 		}
1575 		break;
1576 	default:
1577 		IEEE80211_NOTE(vap,
1578 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1579 		    "%s: category %d not implemented", __func__,
1580 		    ia->ia_category);
1581 		vap->iv_stats.is_rx_mgtdiscard++;
1582 		break;
1583 	}
1584 }
1585 
1586 /*
1587  * Transmit processing.
1588  */
1589 
1590 /*
1591  * Check if A-MPDU should be requested/enabled for a stream.
1592  * We require a traffic rate above a per-AC threshold and we
1593  * also handle backoff from previous failed attempts.
1594  *
1595  * Drivers may override this method to bring in information
1596  * such as link state conditions in making the decision.
1597  */
1598 static int
1599 ieee80211_ampdu_enable(struct ieee80211_node *ni,
1600 	struct ieee80211_tx_ampdu *tap)
1601 {
1602 	struct ieee80211vap *vap = ni->ni_vap;
1603 
1604 	if (tap->txa_avgpps < vap->iv_ampdu_mintraffic[tap->txa_ac])
1605 		return 0;
1606 	/* XXX check rssi? */
1607 	if (tap->txa_attempts >= ieee80211_addba_maxtries &&
1608 	    ticks < tap->txa_nextrequest) {
1609 		/*
1610 		 * Don't retry too often; txa_nextrequest is set
1611 		 * to the minimum interval we'll retry after
1612 		 * ieee80211_addba_maxtries failed attempts are made.
1613 		 */
1614 		return 0;
1615 	}
1616 	IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
1617 	    "%s: enable AMPDU on %s, avgpps %d pkts %d",
1618 	    __func__, ieee80211_wme_acnames[tap->txa_ac],
1619 	    tap->txa_avgpps, tap->txa_pkts);
1620 	return 1;
1621 }
1622 
1623 /*
1624  * Request A-MPDU tx aggregation.  Setup local state and
1625  * issue an ADDBA request.  BA use will only happen after
1626  * the other end replies with ADDBA response.
1627  */
1628 int
1629 ieee80211_ampdu_request(struct ieee80211_node *ni,
1630 	struct ieee80211_tx_ampdu *tap)
1631 {
1632 	struct ieee80211com *ic = ni->ni_ic;
1633 	uint16_t args[4];
1634 	int tid, dialogtoken;
1635 	static int tokens = 0;	/* XXX */
1636 
1637 	/* XXX locking */
1638 	if ((tap->txa_flags & IEEE80211_AGGR_SETUP) == 0) {
1639 		/* do deferred setup of state */
1640 		IEEE80211_TAPQ_INIT(tap);
1641 		callout_init(&tap->txa_timer, CALLOUT_MPSAFE);
1642 		tap->txa_flags |= IEEE80211_AGGR_SETUP;
1643 	}
1644 	/* XXX hack for not doing proper locking */
1645 	tap->txa_flags &= ~IEEE80211_AGGR_NAK;
1646 
1647 	dialogtoken = (tokens+1) % 63;		/* XXX */
1648 
1649 	tid = WME_AC_TO_TID(tap->txa_ac);
1650 	args[0] = dialogtoken;
1651 	args[1]	= IEEE80211_BAPS_POLICY_IMMEDIATE
1652 		| SM(tid, IEEE80211_BAPS_TID)
1653 		| SM(IEEE80211_AGGR_BAWMAX, IEEE80211_BAPS_BUFSIZ)
1654 		;
1655 	args[2] = 0;	/* batimeout */
1656 	/* NB: do first so there's no race against reply */
1657 	if (!ic->ic_addba_request(ni, tap, dialogtoken, args[1], args[2])) {
1658 		/* unable to setup state, don't make request */
1659 		IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_11N,
1660 		    ni, "%s: could not setup BA stream for AC %d",
1661 		    __func__, tap->txa_ac);
1662 		/* defer next try so we don't slam the driver with requests */
1663 		tap->txa_attempts = ieee80211_addba_maxtries;
1664 		/* NB: check in case driver wants to override */
1665 		if (tap->txa_nextrequest <= ticks)
1666 			tap->txa_nextrequest = ticks + ieee80211_addba_backoff;
1667 		return 0;
1668 	}
1669 	tokens = dialogtoken;			/* allocate token */
1670 	/* NB: after calling ic_addba_request so driver can set seqstart */
1671 	args[3] = SM(tap->txa_seqstart, IEEE80211_BASEQ_START)
1672 		| SM(0, IEEE80211_BASEQ_FRAG)
1673 		;
1674 	return ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
1675 		IEEE80211_ACTION_BA_ADDBA_REQUEST, args);
1676 }
1677 
1678 /*
1679  * Terminate an AMPDU tx stream.  State is reclaimed
1680  * and the peer notified with a DelBA Action frame.
1681  */
1682 void
1683 ieee80211_ampdu_stop(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap)
1684 {
1685 	struct ieee80211com *ic = ni->ni_ic;
1686 	struct ieee80211vap *vap = ni->ni_vap;
1687 	uint16_t args[4];
1688 
1689 	/* XXX locking */
1690 	if (IEEE80211_AMPDU_RUNNING(tap)) {
1691 		IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1692 		    ni, "%s: stop BA stream for AC %d", __func__, tap->txa_ac);
1693 		vap->iv_stats.is_ampdu_stop++;
1694 
1695 		ic->ic_addba_stop(ni, tap);
1696 		args[0] = WME_AC_TO_TID(tap->txa_ac);
1697 		args[1] = IEEE80211_DELBAPS_INIT;
1698 		args[2] = 1;				/* XXX reason code */
1699 		ieee80211_send_action(ni, IEEE80211_ACTION_CAT_BA,
1700 			IEEE80211_ACTION_BA_DELBA, args);
1701 	} else {
1702 		IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1703 		    ni, "%s: BA stream for AC %d not running",
1704 		    __func__, tap->txa_ac);
1705 		vap->iv_stats.is_ampdu_stop_failed++;
1706 	}
1707 }
1708 
1709 /*
1710  * Transmit a BAR frame to the specified node.  The
1711  * BAR contents are drawn from the supplied aggregation
1712  * state associated with the node.
1713  */
1714 int
1715 ieee80211_send_bar(struct ieee80211_node *ni,
1716 	const struct ieee80211_tx_ampdu *tap)
1717 {
1718 #define	senderr(_x, _v)	do { vap->iv_stats._v++; ret = _x; goto bad; } while (0)
1719 #define	ADDSHORT(frm, v) do {			\
1720 	frm[0] = (v) & 0xff;			\
1721 	frm[1] = (v) >> 8;			\
1722 	frm += 2;				\
1723 } while (0)
1724 	struct ieee80211vap *vap = ni->ni_vap;
1725 	struct ieee80211com *ic = ni->ni_ic;
1726 	struct ieee80211_frame_min *wh;
1727 	struct mbuf *m;
1728 	uint8_t *frm;
1729 	uint16_t barctl, barseqctl;
1730 	int tid, ret;
1731 
1732 	ieee80211_ref_node(ni);
1733 
1734 	m = ieee80211_getmgtframe(&frm,
1735 		ic->ic_headroom + sizeof(struct ieee80211_frame_min),
1736 		sizeof(struct ieee80211_ba_request)
1737 	);
1738 	if (m == NULL)
1739 		senderr(ENOMEM, is_tx_nobuf);
1740 
1741 	wh = mtod(m, struct ieee80211_frame_min *);
1742 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 |
1743 		IEEE80211_FC0_TYPE_CTL | IEEE80211_FC0_SUBTYPE_BAR;
1744 	wh->i_fc[1] = 0;
1745 	IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_macaddr);
1746 	IEEE80211_ADDR_COPY(wh->i_addr2, vap->iv_myaddr);
1747 
1748 	tid = WME_AC_TO_TID(tap->txa_ac);
1749 	barctl 	= (tap->txa_flags & IEEE80211_AGGR_IMMEDIATE ?
1750 			IEEE80211_BAPS_POLICY_IMMEDIATE :
1751 			IEEE80211_BAPS_POLICY_DELAYED)
1752 		| SM(tid, IEEE80211_BAPS_TID)
1753 		| SM(tap->txa_wnd, IEEE80211_BAPS_BUFSIZ)
1754 		;
1755 	barseqctl = SM(tap->txa_start, IEEE80211_BASEQ_START)
1756 		| SM(0, IEEE80211_BASEQ_FRAG)
1757 		;
1758 	ADDSHORT(frm, barctl);
1759 	ADDSHORT(frm, barseqctl);
1760 	m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1761 
1762 	M_WME_SETAC(m, WME_AC_VO);
1763 
1764 	IEEE80211_NODE_STAT(ni, tx_mgmt);	/* XXX tx_ctl? */
1765 
1766 	IEEE80211_NOTE(vap, IEEE80211_MSG_DEBUG | IEEE80211_MSG_DUMPPKTS,
1767 	    ni, "send bar frame (tid %u start %u) on channel %u",
1768 	    tid, tap->txa_start, ieee80211_chan2ieee(ic, ic->ic_curchan));
1769 
1770 	return ic->ic_raw_xmit(ni, m, NULL);
1771 bad:
1772 	ieee80211_free_node(ni);
1773 	return ret;
1774 #undef ADDSHORT
1775 #undef senderr
1776 }
1777 
1778 /*
1779  * Send an action management frame.  The arguments are stuff
1780  * into a frame without inspection; the caller is assumed to
1781  * prepare them carefully (e.g. based on the aggregation state).
1782  */
1783 int
1784 ieee80211_send_action(struct ieee80211_node *ni,
1785 	int category, int action, uint16_t args[4])
1786 {
1787 #define	senderr(_x, _v)	do { vap->iv_stats._v++; ret = _x; goto bad; } while (0)
1788 #define	ADDSHORT(frm, v) do {			\
1789 	frm[0] = (v) & 0xff;			\
1790 	frm[1] = (v) >> 8;			\
1791 	frm += 2;				\
1792 } while (0)
1793 	struct ieee80211vap *vap = ni->ni_vap;
1794 	struct ieee80211com *ic = ni->ni_ic;
1795 	struct mbuf *m;
1796 	uint8_t *frm;
1797 	uint16_t baparamset;
1798 	int ret;
1799 
1800 	KASSERT(ni != NULL, ("null node"));
1801 
1802 	/*
1803 	 * Hold a reference on the node so it doesn't go away until after
1804 	 * the xmit is complete all the way in the driver.  On error we
1805 	 * will remove our reference.
1806 	 */
1807 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
1808 		"ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n",
1809 		__func__, __LINE__,
1810 		ni, ether_sprintf(ni->ni_macaddr),
1811 		ieee80211_node_refcnt(ni)+1);
1812 	ieee80211_ref_node(ni);
1813 
1814 	m = ieee80211_getmgtframe(&frm,
1815 		ic->ic_headroom + sizeof(struct ieee80211_frame),
1816 		  sizeof(uint16_t)	/* action+category */
1817 		/* XXX may action payload */
1818 		+ sizeof(struct ieee80211_action_ba_addbaresponse)
1819 	);
1820 	if (m == NULL)
1821 		senderr(ENOMEM, is_tx_nobuf);
1822 
1823 	*frm++ = category;
1824 	*frm++ = action;
1825 	switch (category) {
1826 	case IEEE80211_ACTION_CAT_BA:
1827 		switch (action) {
1828 		case IEEE80211_ACTION_BA_ADDBA_REQUEST:
1829 			IEEE80211_NOTE(vap,
1830 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1831 			    "send ADDBA request: dialogtoken %d "
1832 			    "baparamset 0x%x (tid %d) batimeout 0x%x baseqctl 0x%x",
1833 			    args[0], args[1], MS(args[1], IEEE80211_BAPS_TID),
1834 			    args[2], args[3]);
1835 
1836 			*frm++ = args[0];	/* dialog token */
1837 			ADDSHORT(frm, args[1]);	/* baparamset */
1838 			ADDSHORT(frm, args[2]);	/* batimeout */
1839 			ADDSHORT(frm, args[3]);	/* baseqctl */
1840 			break;
1841 		case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
1842 			IEEE80211_NOTE(vap,
1843 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1844 			    "send ADDBA response: dialogtoken %d status %d "
1845 			    "baparamset 0x%x (tid %d) batimeout %d",
1846 			    args[0], args[1], args[2],
1847 			    MS(args[2], IEEE80211_BAPS_TID), args[3]);
1848 
1849 			*frm++ = args[0];	/* dialog token */
1850 			ADDSHORT(frm, args[1]);	/* statuscode */
1851 			ADDSHORT(frm, args[2]);	/* baparamset */
1852 			ADDSHORT(frm, args[3]);	/* batimeout */
1853 			break;
1854 		case IEEE80211_ACTION_BA_DELBA:
1855 			/* XXX */
1856 			baparamset = SM(args[0], IEEE80211_DELBAPS_TID)
1857 				   | args[1]
1858 				   ;
1859 			ADDSHORT(frm, baparamset);
1860 			ADDSHORT(frm, args[2]);	/* reason code */
1861 
1862 			IEEE80211_NOTE(vap,
1863 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1864 			    "send DELBA action: tid %d, initiator %d reason %d",
1865 			    args[0], args[1], args[2]);
1866 			break;
1867 		default:
1868 			goto badaction;
1869 		}
1870 		break;
1871 	case IEEE80211_ACTION_CAT_HT:
1872 		switch (action) {
1873 		case IEEE80211_ACTION_HT_TXCHWIDTH:
1874 			IEEE80211_NOTE(vap,
1875 			    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1876 			    ni, "send HT txchwidth: width %d",
1877 			    IEEE80211_IS_CHAN_HT40(ni->ni_chan) ? 40 : 20
1878 			);
1879 			*frm++ = IEEE80211_IS_CHAN_HT40(ni->ni_chan) ?
1880 				IEEE80211_A_HT_TXCHWIDTH_2040 :
1881 				IEEE80211_A_HT_TXCHWIDTH_20;
1882 			break;
1883 		default:
1884 			goto badaction;
1885 		}
1886 		break;
1887 	default:
1888 	badaction:
1889 		IEEE80211_NOTE(vap,
1890 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1891 		    "%s: unsupported category %d action %d", __func__,
1892 		    category, action);
1893 		senderr(EINVAL, is_tx_unknownmgt);
1894 		/* NOTREACHED */
1895 	}
1896 	m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
1897 
1898 	return ieee80211_mgmt_output(ni, m, IEEE80211_FC0_SUBTYPE_ACTION);
1899 bad:
1900 	ieee80211_free_node(ni);
1901 	if (m != NULL)
1902 		m_freem(m);
1903 	return ret;
1904 #undef ADDSHORT
1905 #undef senderr
1906 }
1907 
1908 /*
1909  * Construct the MCS bit mask for inclusion
1910  * in an HT information element.
1911  */
1912 static void
1913 ieee80211_set_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
1914 {
1915 	int i;
1916 
1917 	for (i = 0; i < rs->rs_nrates; i++) {
1918 		int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
1919 		if (r < IEEE80211_HTRATE_MAXSIZE) {	/* XXX? */
1920 			/* NB: this assumes a particular implementation */
1921 			setbit(frm, r);
1922 		}
1923 	}
1924 }
1925 
1926 /*
1927  * Add body of an HTCAP information element.
1928  */
1929 static uint8_t *
1930 ieee80211_add_htcap_body(uint8_t *frm, struct ieee80211_node *ni)
1931 {
1932 #define	ADDSHORT(frm, v) do {			\
1933 	frm[0] = (v) & 0xff;			\
1934 	frm[1] = (v) >> 8;			\
1935 	frm += 2;				\
1936 } while (0)
1937 	struct ieee80211vap *vap = ni->ni_vap;
1938 	uint16_t caps;
1939 	int rxmax, density;
1940 
1941 	/* HT capabilities */
1942 	caps = vap->iv_htcaps & 0xffff;
1943 	/*
1944 	 * Note channel width depends on whether we are operating as
1945 	 * a sta or not.  When operating as a sta we are generating
1946 	 * a request based on our desired configuration.  Otherwise
1947 	 * we are operational and the channel attributes identify
1948 	 * how we've been setup (which might be different if a fixed
1949 	 * channel is specified).
1950 	 */
1951 	if (vap->iv_opmode == IEEE80211_M_STA) {
1952 		/* override 20/40 use based on config */
1953 		if (vap->iv_flags_ext & IEEE80211_FEXT_USEHT40)
1954 			caps |= IEEE80211_HTCAP_CHWIDTH40;
1955 		else
1956 			caps &= ~IEEE80211_HTCAP_CHWIDTH40;
1957 		/* use advertised setting (XXX locally constraint) */
1958 		rxmax = MS(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU);
1959 		density = MS(ni->ni_htparam, IEEE80211_HTCAP_MPDUDENSITY);
1960 	} else {
1961 		/* override 20/40 use based on current channel */
1962 		if (IEEE80211_IS_CHAN_HT40(ni->ni_chan))
1963 			caps |= IEEE80211_HTCAP_CHWIDTH40;
1964 		else
1965 			caps &= ~IEEE80211_HTCAP_CHWIDTH40;
1966 		rxmax = vap->iv_ampdu_rxmax;
1967 		density = vap->iv_ampdu_density;
1968 	}
1969 	/* adjust short GI based on channel and config */
1970 	if ((vap->iv_flags_ext & IEEE80211_FEXT_SHORTGI20) == 0)
1971 		caps &= ~IEEE80211_HTCAP_SHORTGI20;
1972 	if ((vap->iv_flags_ext & IEEE80211_FEXT_SHORTGI40) == 0 ||
1973 	    (caps & IEEE80211_HTCAP_CHWIDTH40) == 0)
1974 		caps &= ~IEEE80211_HTCAP_SHORTGI40;
1975 	ADDSHORT(frm, caps);
1976 
1977 	/* HT parameters */
1978 	*frm = SM(rxmax, IEEE80211_HTCAP_MAXRXAMPDU)
1979 	     | SM(density, IEEE80211_HTCAP_MPDUDENSITY)
1980 	     ;
1981 	frm++;
1982 
1983 	/* pre-zero remainder of ie */
1984 	memset(frm, 0, sizeof(struct ieee80211_ie_htcap) -
1985 		__offsetof(struct ieee80211_ie_htcap, hc_mcsset));
1986 
1987 	/* supported MCS set */
1988 	/*
1989 	 * XXX it would better to get the rate set from ni_htrates
1990 	 * so we can restrict it but for sta mode ni_htrates isn't
1991 	 * setup when we're called to form an AssocReq frame so for
1992 	 * now we're restricted to the default HT rate set.
1993 	 */
1994 	ieee80211_set_htrates(frm, &ieee80211_rateset_11n);
1995 
1996 	frm += sizeof(struct ieee80211_ie_htcap) -
1997 		__offsetof(struct ieee80211_ie_htcap, hc_mcsset);
1998 	return frm;
1999 #undef ADDSHORT
2000 }
2001 
2002 /*
2003  * Add 802.11n HT capabilities information element
2004  */
2005 uint8_t *
2006 ieee80211_add_htcap(uint8_t *frm, struct ieee80211_node *ni)
2007 {
2008 	frm[0] = IEEE80211_ELEMID_HTCAP;
2009 	frm[1] = sizeof(struct ieee80211_ie_htcap) - 2;
2010 	return ieee80211_add_htcap_body(frm + 2, ni);
2011 }
2012 
2013 /*
2014  * Add Broadcom OUI wrapped standard HTCAP ie; this is
2015  * used for compatibility w/ pre-draft implementations.
2016  */
2017 uint8_t *
2018 ieee80211_add_htcap_vendor(uint8_t *frm, struct ieee80211_node *ni)
2019 {
2020 	frm[0] = IEEE80211_ELEMID_VENDOR;
2021 	frm[1] = 4 + sizeof(struct ieee80211_ie_htcap) - 2;
2022 	frm[2] = (BCM_OUI >> 0) & 0xff;
2023 	frm[3] = (BCM_OUI >> 8) & 0xff;
2024 	frm[4] = (BCM_OUI >> 16) & 0xff;
2025 	frm[5] = BCM_OUI_HTCAP;
2026 	return ieee80211_add_htcap_body(frm + 6, ni);
2027 }
2028 
2029 /*
2030  * Construct the MCS bit mask of basic rates
2031  * for inclusion in an HT information element.
2032  */
2033 static void
2034 ieee80211_set_basic_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
2035 {
2036 	int i;
2037 
2038 	for (i = 0; i < rs->rs_nrates; i++) {
2039 		int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
2040 		if ((rs->rs_rates[i] & IEEE80211_RATE_BASIC) &&
2041 		    r < IEEE80211_HTRATE_MAXSIZE) {
2042 			/* NB: this assumes a particular implementation */
2043 			setbit(frm, r);
2044 		}
2045 	}
2046 }
2047 
2048 /*
2049  * Update the HTINFO ie for a beacon frame.
2050  */
2051 void
2052 ieee80211_ht_update_beacon(struct ieee80211vap *vap,
2053 	struct ieee80211_beacon_offsets *bo)
2054 {
2055 #define	PROTMODE	(IEEE80211_HTINFO_OPMODE|IEEE80211_HTINFO_NONHT_PRESENT)
2056 	const struct ieee80211_channel *bsschan = vap->iv_bss->ni_chan;
2057 	struct ieee80211com *ic = vap->iv_ic;
2058 	struct ieee80211_ie_htinfo *ht =
2059 	   (struct ieee80211_ie_htinfo *) bo->bo_htinfo;
2060 
2061 	/* XXX only update on channel change */
2062 	ht->hi_ctrlchannel = ieee80211_chan2ieee(ic, bsschan);
2063 	ht->hi_byte1 = IEEE80211_HTINFO_RIFSMODE_PROH;
2064 	if (IEEE80211_IS_CHAN_HT40U(bsschan))
2065 		ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
2066 	else if (IEEE80211_IS_CHAN_HT40D(bsschan))
2067 		ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_BELOW;
2068 	else
2069 		ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_NONE;
2070 	if (IEEE80211_IS_CHAN_HT40(bsschan))
2071 		ht->hi_byte1 |= IEEE80211_HTINFO_TXWIDTH_2040;
2072 
2073 	/* protection mode */
2074 	ht->hi_byte2 = (ht->hi_byte2 &~ PROTMODE) | ic->ic_curhtprotmode;
2075 
2076 	/* XXX propagate to vendor ie's */
2077 #undef PROTMODE
2078 }
2079 
2080 /*
2081  * Add body of an HTINFO information element.
2082  *
2083  * NB: We don't use struct ieee80211_ie_htinfo because we can
2084  * be called to fillin both a standard ie and a compat ie that
2085  * has a vendor OUI at the front.
2086  */
2087 static uint8_t *
2088 ieee80211_add_htinfo_body(uint8_t *frm, struct ieee80211_node *ni)
2089 {
2090 	struct ieee80211com *ic = ni->ni_ic;
2091 
2092 	/* pre-zero remainder of ie */
2093 	memset(frm, 0, sizeof(struct ieee80211_ie_htinfo) - 2);
2094 
2095 	/* primary/control channel center */
2096 	*frm++ = ieee80211_chan2ieee(ic, ni->ni_chan);
2097 
2098 	frm[0] = IEEE80211_HTINFO_RIFSMODE_PROH;
2099 	if (IEEE80211_IS_CHAN_HT40U(ni->ni_chan))
2100 		frm[0] |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
2101 	else if (IEEE80211_IS_CHAN_HT40D(ni->ni_chan))
2102 		frm[0] |= IEEE80211_HTINFO_2NDCHAN_BELOW;
2103 	else
2104 		frm[0] |= IEEE80211_HTINFO_2NDCHAN_NONE;
2105 	if (IEEE80211_IS_CHAN_HT40(ni->ni_chan))
2106 		frm[0] |= IEEE80211_HTINFO_TXWIDTH_2040;
2107 
2108 	frm[1] = ic->ic_curhtprotmode;
2109 
2110 	frm += 5;
2111 
2112 	/* basic MCS set */
2113 	ieee80211_set_basic_htrates(frm, &ni->ni_htrates);
2114 	frm += sizeof(struct ieee80211_ie_htinfo) -
2115 		__offsetof(struct ieee80211_ie_htinfo, hi_basicmcsset);
2116 	return frm;
2117 }
2118 
2119 /*
2120  * Add 802.11n HT information information element.
2121  */
2122 uint8_t *
2123 ieee80211_add_htinfo(uint8_t *frm, struct ieee80211_node *ni)
2124 {
2125 	frm[0] = IEEE80211_ELEMID_HTINFO;
2126 	frm[1] = sizeof(struct ieee80211_ie_htinfo) - 2;
2127 	return ieee80211_add_htinfo_body(frm + 2, ni);
2128 }
2129 
2130 /*
2131  * Add Broadcom OUI wrapped standard HTINFO ie; this is
2132  * used for compatibility w/ pre-draft implementations.
2133  */
2134 uint8_t *
2135 ieee80211_add_htinfo_vendor(uint8_t *frm, struct ieee80211_node *ni)
2136 {
2137 	frm[0] = IEEE80211_ELEMID_VENDOR;
2138 	frm[1] = 4 + sizeof(struct ieee80211_ie_htinfo) - 2;
2139 	frm[2] = (BCM_OUI >> 0) & 0xff;
2140 	frm[3] = (BCM_OUI >> 8) & 0xff;
2141 	frm[4] = (BCM_OUI >> 16) & 0xff;
2142 	frm[5] = BCM_OUI_HTINFO;
2143 	return ieee80211_add_htinfo_body(frm + 6, ni);
2144 }
2145