xref: /freebsd/sys/net80211/ieee80211_ht.c (revision 3157ba21)
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_action.h>
51 #include <net80211/ieee80211_input.h>
52 
53 /* define here, used throughout file */
54 #define	MS(_v, _f)	(((_v) & _f) >> _f##_S)
55 #define	SM(_v, _f)	(((_v) << _f##_S) & _f)
56 
57 const struct ieee80211_mcs_rates ieee80211_htrates[16] = {
58     /*  20Mhz  SGI 40Mhz  SGI */
59 	{  13,  14,  27,  30 },	/* MCS 0 */
60 	{  26,  29,  54,  60 },	/* MCS 1 */
61 	{  39,  43,  81,  90 },	/* MCS 2 */
62 	{  52,  58, 108, 120 },	/* MCS 3 */
63 	{  78,  87, 162, 180 },	/* MCS 4 */
64 	{ 104, 116, 216, 240 },	/* MCS 5 */
65 	{ 117, 130, 243, 270 },	/* MCS 6 */
66 	{ 130, 144, 270, 300 },	/* MCS 7 */
67 	{  26,  29,  54,  60 },	/* MCS 8 */
68 	{  52,  58, 108, 120 },	/* MCS 9 */
69 	{  78,  87, 162, 180 },	/* MCS 10 */
70 	{ 104, 116, 216, 240 },	/* MCS 11 */
71 	{ 156, 173, 324, 360 },	/* MCS 12 */
72 	{ 208, 231, 432, 480 },	/* MCS 13 */
73 	{ 234, 260, 486, 540 },	/* MCS 14 */
74 	{ 260, 289, 540, 600 }	/* MCS 15 */
75 };
76 
77 static const struct ieee80211_htrateset ieee80211_rateset_11n =
78 	{ 16, {
79 	          0,   1,   2,   3,   4,  5,   6,  7,  8,  9,
80 		 10,  11,  12,  13,  14,  15 }
81 	};
82 
83 #ifdef IEEE80211_AMPDU_AGE
84 static	int ieee80211_ampdu_age = -1;	/* threshold for ampdu reorder q (ms) */
85 SYSCTL_PROC(_net_wlan, OID_AUTO, ampdu_age, CTLTYPE_INT | CTLFLAG_RW,
86 	&ieee80211_ampdu_age, 0, ieee80211_sysctl_msecs_ticks, "I",
87 	"AMPDU max reorder age (ms)");
88 #endif
89 
90 static	int ieee80211_recv_bar_ena = 1;
91 SYSCTL_INT(_net_wlan, OID_AUTO, recv_bar, CTLFLAG_RW, &ieee80211_recv_bar_ena,
92 	    0, "BAR frame processing (ena/dis)");
93 
94 static	int ieee80211_addba_timeout = -1;/* timeout for ADDBA response */
95 SYSCTL_PROC(_net_wlan, OID_AUTO, addba_timeout, CTLTYPE_INT | CTLFLAG_RW,
96 	&ieee80211_addba_timeout, 0, ieee80211_sysctl_msecs_ticks, "I",
97 	"ADDBA request timeout (ms)");
98 static	int ieee80211_addba_backoff = -1;/* backoff after max ADDBA requests */
99 SYSCTL_PROC(_net_wlan, OID_AUTO, addba_backoff, CTLTYPE_INT | CTLFLAG_RW,
100 	&ieee80211_addba_backoff, 0, ieee80211_sysctl_msecs_ticks, "I",
101 	"ADDBA request backoff (ms)");
102 static	int ieee80211_addba_maxtries = 3;/* max ADDBA requests before backoff */
103 SYSCTL_INT(_net_wlan, OID_AUTO, addba_maxtries, CTLTYPE_INT | CTLFLAG_RW,
104 	&ieee80211_addba_maxtries, 0, "max ADDBA requests sent before backoff");
105 
106 static	int ieee80211_bar_timeout = -1;	/* timeout waiting for BAR response */
107 static	int ieee80211_bar_maxtries = 50;/* max BAR requests before DELBA */
108 
109 static	ieee80211_recv_action_func ht_recv_action_ba_addba_request;
110 static	ieee80211_recv_action_func ht_recv_action_ba_addba_response;
111 static	ieee80211_recv_action_func ht_recv_action_ba_delba;
112 static	ieee80211_recv_action_func ht_recv_action_ht_mimopwrsave;
113 static	ieee80211_recv_action_func ht_recv_action_ht_txchwidth;
114 
115 static	ieee80211_send_action_func ht_send_action_ba_addba;
116 static	ieee80211_send_action_func ht_send_action_ba_delba;
117 static	ieee80211_send_action_func ht_send_action_ht_txchwidth;
118 
119 static void
120 ieee80211_ht_init(void)
121 {
122 	/*
123 	 * Setup HT parameters that depends on the clock frequency.
124 	 */
125 #ifdef IEEE80211_AMPDU_AGE
126 	ieee80211_ampdu_age = msecs_to_ticks(500);
127 #endif
128 	ieee80211_addba_timeout = msecs_to_ticks(250);
129 	ieee80211_addba_backoff = msecs_to_ticks(10*1000);
130 	ieee80211_bar_timeout = msecs_to_ticks(250);
131 	/*
132 	 * Register action frame handlers.
133 	 */
134 	ieee80211_recv_action_register(IEEE80211_ACTION_CAT_BA,
135 	    IEEE80211_ACTION_BA_ADDBA_REQUEST, ht_recv_action_ba_addba_request);
136 	ieee80211_recv_action_register(IEEE80211_ACTION_CAT_BA,
137 	    IEEE80211_ACTION_BA_ADDBA_RESPONSE, ht_recv_action_ba_addba_response);
138 	ieee80211_recv_action_register(IEEE80211_ACTION_CAT_BA,
139 	    IEEE80211_ACTION_BA_DELBA, ht_recv_action_ba_delba);
140 	ieee80211_recv_action_register(IEEE80211_ACTION_CAT_HT,
141 	    IEEE80211_ACTION_HT_MIMOPWRSAVE, ht_recv_action_ht_mimopwrsave);
142 	ieee80211_recv_action_register(IEEE80211_ACTION_CAT_HT,
143 	    IEEE80211_ACTION_HT_TXCHWIDTH, ht_recv_action_ht_txchwidth);
144 
145 	ieee80211_send_action_register(IEEE80211_ACTION_CAT_BA,
146 	    IEEE80211_ACTION_BA_ADDBA_REQUEST, ht_send_action_ba_addba);
147 	ieee80211_send_action_register(IEEE80211_ACTION_CAT_BA,
148 	    IEEE80211_ACTION_BA_ADDBA_RESPONSE, ht_send_action_ba_addba);
149 	ieee80211_send_action_register(IEEE80211_ACTION_CAT_BA,
150 	    IEEE80211_ACTION_BA_DELBA, ht_send_action_ba_delba);
151 	ieee80211_send_action_register(IEEE80211_ACTION_CAT_HT,
152 	    IEEE80211_ACTION_HT_TXCHWIDTH, ht_send_action_ht_txchwidth);
153 }
154 SYSINIT(wlan_ht, SI_SUB_DRIVERS, SI_ORDER_FIRST, ieee80211_ht_init, NULL);
155 
156 static int ieee80211_ampdu_enable(struct ieee80211_node *ni,
157 	struct ieee80211_tx_ampdu *tap);
158 static int ieee80211_addba_request(struct ieee80211_node *ni,
159 	struct ieee80211_tx_ampdu *tap,
160 	int dialogtoken, int baparamset, int batimeout);
161 static int ieee80211_addba_response(struct ieee80211_node *ni,
162 	struct ieee80211_tx_ampdu *tap,
163 	int code, int baparamset, int batimeout);
164 static void ieee80211_addba_stop(struct ieee80211_node *ni,
165 	struct ieee80211_tx_ampdu *tap);
166 static void ieee80211_bar_response(struct ieee80211_node *ni,
167 	struct ieee80211_tx_ampdu *tap, int status);
168 static void ampdu_tx_stop(struct ieee80211_tx_ampdu *tap);
169 static void bar_stop_timer(struct ieee80211_tx_ampdu *tap);
170 static int ampdu_rx_start(struct ieee80211_node *, struct ieee80211_rx_ampdu *,
171 	int baparamset, int batimeout, int baseqctl);
172 static void ampdu_rx_stop(struct ieee80211_node *, struct ieee80211_rx_ampdu *);
173 
174 void
175 ieee80211_ht_attach(struct ieee80211com *ic)
176 {
177 	/* setup default aggregation policy */
178 	ic->ic_recv_action = ieee80211_recv_action;
179 	ic->ic_send_action = ieee80211_send_action;
180 	ic->ic_ampdu_enable = ieee80211_ampdu_enable;
181 	ic->ic_addba_request = ieee80211_addba_request;
182 	ic->ic_addba_response = ieee80211_addba_response;
183 	ic->ic_addba_stop = ieee80211_addba_stop;
184 	ic->ic_bar_response = ieee80211_bar_response;
185 	ic->ic_ampdu_rx_start = ampdu_rx_start;
186 	ic->ic_ampdu_rx_stop = ampdu_rx_stop;
187 
188 	ic->ic_htprotmode = IEEE80211_PROT_RTSCTS;
189 	ic->ic_curhtprotmode = IEEE80211_HTINFO_OPMODE_PURE;
190 }
191 
192 void
193 ieee80211_ht_detach(struct ieee80211com *ic)
194 {
195 }
196 
197 void
198 ieee80211_ht_vattach(struct ieee80211vap *vap)
199 {
200 
201 	/* driver can override defaults */
202 	vap->iv_ampdu_rxmax = IEEE80211_HTCAP_MAXRXAMPDU_8K;
203 	vap->iv_ampdu_density = IEEE80211_HTCAP_MPDUDENSITY_NA;
204 	vap->iv_ampdu_limit = vap->iv_ampdu_rxmax;
205 	vap->iv_amsdu_limit = vap->iv_htcaps & IEEE80211_HTCAP_MAXAMSDU;
206 	/* tx aggregation traffic thresholds */
207 	vap->iv_ampdu_mintraffic[WME_AC_BK] = 128;
208 	vap->iv_ampdu_mintraffic[WME_AC_BE] = 64;
209 	vap->iv_ampdu_mintraffic[WME_AC_VO] = 32;
210 	vap->iv_ampdu_mintraffic[WME_AC_VI] = 32;
211 
212 	if (vap->iv_htcaps & IEEE80211_HTC_HT) {
213 		/*
214 		 * Device is HT capable; enable all HT-related
215 		 * facilities by default.
216 		 * XXX these choices may be too aggressive.
217 		 */
218 		vap->iv_flags_ht |= IEEE80211_FHT_HT
219 				 |  IEEE80211_FHT_HTCOMPAT
220 				 ;
221 		if (vap->iv_htcaps & IEEE80211_HTCAP_SHORTGI20)
222 			vap->iv_flags_ht |= IEEE80211_FHT_SHORTGI20;
223 		/* XXX infer from channel list? */
224 		if (vap->iv_htcaps & IEEE80211_HTCAP_CHWIDTH40) {
225 			vap->iv_flags_ht |= IEEE80211_FHT_USEHT40;
226 			if (vap->iv_htcaps & IEEE80211_HTCAP_SHORTGI40)
227 				vap->iv_flags_ht |= IEEE80211_FHT_SHORTGI40;
228 		}
229 		/* enable RIFS if capable */
230 		if (vap->iv_htcaps & IEEE80211_HTC_RIFS)
231 			vap->iv_flags_ht |= IEEE80211_FHT_RIFS;
232 
233 		/* NB: A-MPDU and A-MSDU rx are mandated, these are tx only */
234 		vap->iv_flags_ht |= IEEE80211_FHT_AMPDU_RX;
235 		if (vap->iv_htcaps & IEEE80211_HTC_AMPDU)
236 			vap->iv_flags_ht |= IEEE80211_FHT_AMPDU_TX;
237 		vap->iv_flags_ht |= IEEE80211_FHT_AMSDU_RX;
238 		if (vap->iv_htcaps & IEEE80211_HTC_AMSDU)
239 			vap->iv_flags_ht |= IEEE80211_FHT_AMSDU_TX;
240 	}
241 	/* NB: disable default legacy WDS, too many issues right now */
242 	if (vap->iv_flags_ext & IEEE80211_FEXT_WDSLEGACY)
243 		vap->iv_flags_ht &= ~IEEE80211_FHT_HT;
244 }
245 
246 void
247 ieee80211_ht_vdetach(struct ieee80211vap *vap)
248 {
249 }
250 
251 static void
252 ht_rateprint(struct ieee80211com *ic, int mode,
253 	const struct ieee80211_htrateset *rs, int maxmcs, int ratetype)
254 {
255 	int i, rate, mword;
256 
257 	for (i = 0; i < rs->rs_nrates && i < maxmcs; i++) {
258 		mword = ieee80211_rate2media(ic,
259 		    rs->rs_rates[i] | IEEE80211_RATE_MCS, mode);
260 		if (IFM_SUBTYPE(mword) != IFM_IEEE80211_MCS)
261 			continue;
262 		switch (ratetype) {
263 		case 0:
264 			rate = ieee80211_htrates[
265 			    rs->rs_rates[i]].ht20_rate_800ns;
266 			break;
267 		case 1:
268 			rate = ieee80211_htrates[
269 			    rs->rs_rates[i]].ht20_rate_400ns;
270 			break;
271 		case 2:
272 			rate = ieee80211_htrates[
273 			    rs->rs_rates[i]].ht40_rate_800ns;
274 			break;
275 		default:
276 			rate = ieee80211_htrates[
277 			    rs->rs_rates[i]].ht40_rate_400ns;
278 			break;
279 		}
280 		printf("%s%d%sMbps", (i != 0 ? " " : ""),
281 		    rate / 2, ((rate & 0x1) != 0 ? ".5" : ""));
282 	}
283 	printf("\n");
284 }
285 
286 static void
287 ht_announce(struct ieee80211com *ic, int mode,
288 	const struct ieee80211_htrateset *rs)
289 {
290 	struct ifnet *ifp = ic->ic_ifp;
291 	int maxmcs = 2 * 8;
292 	const char *modestr = ieee80211_phymode_name[mode];
293 
294 	KASSERT(maxmcs <= 16, ("maxmcs > 16"));
295 	if_printf(ifp, "%d MCS rates\n", maxmcs);
296 	if_printf(ifp, "%s MCS 20Mhz: ", modestr);
297 	ht_rateprint(ic, mode, rs, maxmcs, 0);
298 	if_printf(ifp, "%s MCS 20Mhz SGI: ", modestr);
299 	ht_rateprint(ic, mode, rs, maxmcs, 1);
300 	if_printf(ifp, "%s MCS 40Mhz: ", modestr);
301 	ht_rateprint(ic, mode, rs, maxmcs, 2);
302 	if_printf(ifp, "%s MCS 40Mhz SGI: ", modestr);
303 	ht_rateprint(ic, mode, rs, maxmcs, 3);
304 }
305 
306 void
307 ieee80211_ht_announce(struct ieee80211com *ic)
308 {
309 	if (isset(ic->ic_modecaps, IEEE80211_MODE_11NA))
310 		ht_announce(ic, IEEE80211_MODE_11NA, &ieee80211_rateset_11n);
311 	if (isset(ic->ic_modecaps, IEEE80211_MODE_11NG))
312 		ht_announce(ic, IEEE80211_MODE_11NG, &ieee80211_rateset_11n);
313 }
314 
315 const struct ieee80211_htrateset *
316 ieee80211_get_suphtrates(struct ieee80211com *ic,
317 	const struct ieee80211_channel *c)
318 {
319 	return &ieee80211_rateset_11n;
320 }
321 
322 /*
323  * Receive processing.
324  */
325 
326 /*
327  * Decap the encapsulated A-MSDU frames and dispatch all but
328  * the last for delivery.  The last frame is returned for
329  * delivery via the normal path.
330  */
331 struct mbuf *
332 ieee80211_decap_amsdu(struct ieee80211_node *ni, struct mbuf *m)
333 {
334 	struct ieee80211vap *vap = ni->ni_vap;
335 	int framelen;
336 	struct mbuf *n;
337 
338 	/* discard 802.3 header inserted by ieee80211_decap */
339 	m_adj(m, sizeof(struct ether_header));
340 
341 	vap->iv_stats.is_amsdu_decap++;
342 
343 	for (;;) {
344 		/*
345 		 * Decap the first frame, bust it apart from the
346 		 * remainder and deliver.  We leave the last frame
347 		 * delivery to the caller (for consistency with other
348 		 * code paths, could also do it here).
349 		 */
350 		m = ieee80211_decap1(m, &framelen);
351 		if (m == NULL) {
352 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
353 			    ni->ni_macaddr, "a-msdu", "%s", "decap failed");
354 			vap->iv_stats.is_amsdu_tooshort++;
355 			return NULL;
356 		}
357 		if (m->m_pkthdr.len == framelen)
358 			break;
359 		n = m_split(m, framelen, M_NOWAIT);
360 		if (n == NULL) {
361 			IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_ANY,
362 			    ni->ni_macaddr, "a-msdu",
363 			    "%s", "unable to split encapsulated frames");
364 			vap->iv_stats.is_amsdu_split++;
365 			m_freem(m);			/* NB: must reclaim */
366 			return NULL;
367 		}
368 		vap->iv_deliver_data(vap, ni, m);
369 
370 		/*
371 		 * Remove frame contents; each intermediate frame
372 		 * is required to be aligned to a 4-byte boundary.
373 		 */
374 		m = n;
375 		m_adj(m, roundup2(framelen, 4) - framelen);	/* padding */
376 	}
377 	return m;				/* last delivered by caller */
378 }
379 
380 /*
381  * Purge all frames in the A-MPDU re-order queue.
382  */
383 static void
384 ampdu_rx_purge(struct ieee80211_rx_ampdu *rap)
385 {
386 	struct mbuf *m;
387 	int i;
388 
389 	for (i = 0; i < rap->rxa_wnd; i++) {
390 		m = rap->rxa_m[i];
391 		if (m != NULL) {
392 			rap->rxa_m[i] = NULL;
393 			rap->rxa_qbytes -= m->m_pkthdr.len;
394 			m_freem(m);
395 			if (--rap->rxa_qframes == 0)
396 				break;
397 		}
398 	}
399 	KASSERT(rap->rxa_qbytes == 0 && rap->rxa_qframes == 0,
400 	    ("lost %u data, %u frames on ampdu rx q",
401 	    rap->rxa_qbytes, rap->rxa_qframes));
402 }
403 
404 /*
405  * Start A-MPDU rx/re-order processing for the specified TID.
406  */
407 static int
408 ampdu_rx_start(struct ieee80211_node *ni, struct ieee80211_rx_ampdu *rap,
409 	int baparamset, int batimeout, int baseqctl)
410 {
411 	int bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
412 
413 	if (rap->rxa_flags & IEEE80211_AGGR_RUNNING) {
414 		/*
415 		 * AMPDU previously setup and not terminated with a DELBA,
416 		 * flush the reorder q's in case anything remains.
417 		 */
418 		ampdu_rx_purge(rap);
419 	}
420 	memset(rap, 0, sizeof(*rap));
421 	rap->rxa_wnd = (bufsiz == 0) ?
422 	    IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
423 	rap->rxa_start = MS(baseqctl, IEEE80211_BASEQ_START);
424 	rap->rxa_flags |=  IEEE80211_AGGR_RUNNING | IEEE80211_AGGR_XCHGPEND;
425 
426 	return 0;
427 }
428 
429 /*
430  * Stop A-MPDU rx processing for the specified TID.
431  */
432 static void
433 ampdu_rx_stop(struct ieee80211_node *ni, struct ieee80211_rx_ampdu *rap)
434 {
435 
436 	ampdu_rx_purge(rap);
437 	rap->rxa_flags &= ~(IEEE80211_AGGR_RUNNING | IEEE80211_AGGR_XCHGPEND);
438 }
439 
440 /*
441  * Dispatch a frame from the A-MPDU reorder queue.  The
442  * frame is fed back into ieee80211_input marked with an
443  * M_AMPDU_MPDU flag so it doesn't come back to us (it also
444  * permits ieee80211_input to optimize re-processing).
445  */
446 static __inline void
447 ampdu_dispatch(struct ieee80211_node *ni, struct mbuf *m)
448 {
449 	m->m_flags |= M_AMPDU_MPDU;	/* bypass normal processing */
450 	/* NB: rssi and noise are ignored w/ M_AMPDU_MPDU set */
451 	(void) ieee80211_input(ni, m, 0, 0);
452 }
453 
454 /*
455  * Dispatch as many frames as possible from the re-order queue.
456  * Frames will always be "at the front"; we process all frames
457  * up to the first empty slot in the window.  On completion we
458  * cleanup state if there are still pending frames in the current
459  * BA window.  We assume the frame at slot 0 is already handled
460  * by the caller; we always start at slot 1.
461  */
462 static void
463 ampdu_rx_dispatch(struct ieee80211_rx_ampdu *rap, struct ieee80211_node *ni)
464 {
465 	struct ieee80211vap *vap = ni->ni_vap;
466 	struct mbuf *m;
467 	int i;
468 
469 	/* flush run of frames */
470 	for (i = 1; i < rap->rxa_wnd; i++) {
471 		m = rap->rxa_m[i];
472 		if (m == NULL)
473 			break;
474 		rap->rxa_m[i] = NULL;
475 		rap->rxa_qbytes -= m->m_pkthdr.len;
476 		rap->rxa_qframes--;
477 
478 		ampdu_dispatch(ni, m);
479 	}
480 	/*
481 	 * If frames remain, copy the mbuf pointers down so
482 	 * they correspond to the offsets in the new window.
483 	 */
484 	if (rap->rxa_qframes != 0) {
485 		int n = rap->rxa_qframes, j;
486 		for (j = i+1; j < rap->rxa_wnd; j++) {
487 			if (rap->rxa_m[j] != NULL) {
488 				rap->rxa_m[j-i] = rap->rxa_m[j];
489 				rap->rxa_m[j] = NULL;
490 				if (--n == 0)
491 					break;
492 			}
493 		}
494 		KASSERT(n == 0, ("lost %d frames", n));
495 		vap->iv_stats.is_ampdu_rx_copy += rap->rxa_qframes;
496 	}
497 	/*
498 	 * Adjust the start of the BA window to
499 	 * reflect the frames just dispatched.
500 	 */
501 	rap->rxa_start = IEEE80211_SEQ_ADD(rap->rxa_start, i);
502 	vap->iv_stats.is_ampdu_rx_oor += i;
503 }
504 
505 #ifdef IEEE80211_AMPDU_AGE
506 /*
507  * Dispatch all frames in the A-MPDU re-order queue.
508  */
509 static void
510 ampdu_rx_flush(struct ieee80211_node *ni, struct ieee80211_rx_ampdu *rap)
511 {
512 	struct ieee80211vap *vap = ni->ni_vap;
513 	struct mbuf *m;
514 	int i;
515 
516 	for (i = 0; i < rap->rxa_wnd; i++) {
517 		m = rap->rxa_m[i];
518 		if (m == NULL)
519 			continue;
520 		rap->rxa_m[i] = NULL;
521 		rap->rxa_qbytes -= m->m_pkthdr.len;
522 		rap->rxa_qframes--;
523 		vap->iv_stats.is_ampdu_rx_oor++;
524 
525 		ampdu_dispatch(ni, m);
526 		if (rap->rxa_qframes == 0)
527 			break;
528 	}
529 }
530 #endif /* IEEE80211_AMPDU_AGE */
531 
532 /*
533  * Dispatch all frames in the A-MPDU re-order queue
534  * preceding the specified sequence number.  This logic
535  * handles window moves due to a received MSDU or BAR.
536  */
537 static void
538 ampdu_rx_flush_upto(struct ieee80211_node *ni,
539 	struct ieee80211_rx_ampdu *rap, ieee80211_seq winstart)
540 {
541 	struct ieee80211vap *vap = ni->ni_vap;
542 	struct mbuf *m;
543 	ieee80211_seq seqno;
544 	int i;
545 
546 	/*
547 	 * Flush any complete MSDU's with a sequence number lower
548 	 * than winstart.  Gaps may exist.  Note that we may actually
549 	 * dispatch frames past winstart if a run continues; this is
550 	 * an optimization that avoids having to do a separate pass
551 	 * to dispatch frames after moving the BA window start.
552 	 */
553 	seqno = rap->rxa_start;
554 	for (i = 0; i < rap->rxa_wnd; i++) {
555 		m = rap->rxa_m[i];
556 		if (m != NULL) {
557 			rap->rxa_m[i] = NULL;
558 			rap->rxa_qbytes -= m->m_pkthdr.len;
559 			rap->rxa_qframes--;
560 			vap->iv_stats.is_ampdu_rx_oor++;
561 
562 			ampdu_dispatch(ni, m);
563 		} else {
564 			if (!IEEE80211_SEQ_BA_BEFORE(seqno, winstart))
565 				break;
566 		}
567 		seqno = IEEE80211_SEQ_INC(seqno);
568 	}
569 	/*
570 	 * If frames remain, copy the mbuf pointers down so
571 	 * they correspond to the offsets in the new window.
572 	 */
573 	if (rap->rxa_qframes != 0) {
574 		int n = rap->rxa_qframes, j;
575 
576 		/* NB: this loop assumes i > 0 and/or rxa_m[0] is NULL */
577 		KASSERT(rap->rxa_m[0] == NULL,
578 		    ("%s: BA window slot 0 occupied", __func__));
579 		for (j = i+1; j < rap->rxa_wnd; j++) {
580 			if (rap->rxa_m[j] != NULL) {
581 				rap->rxa_m[j-i] = rap->rxa_m[j];
582 				rap->rxa_m[j] = NULL;
583 				if (--n == 0)
584 					break;
585 			}
586 		}
587 		KASSERT(n == 0, ("%s: lost %d frames, qframes %d off %d "
588 		    "BA win <%d:%d> winstart %d",
589 		    __func__, n, rap->rxa_qframes, i, rap->rxa_start,
590 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
591 		    winstart));
592 		vap->iv_stats.is_ampdu_rx_copy += rap->rxa_qframes;
593 	}
594 	/*
595 	 * Move the start of the BA window; we use the
596 	 * sequence number of the last MSDU that was
597 	 * passed up the stack+1 or winstart if stopped on
598 	 * a gap in the reorder buffer.
599 	 */
600 	rap->rxa_start = seqno;
601 }
602 
603 /*
604  * Process a received QoS data frame for an HT station.  Handle
605  * A-MPDU reordering: if this frame is received out of order
606  * and falls within the BA window hold onto it.  Otherwise if
607  * this frame completes a run, flush any pending frames.  We
608  * return 1 if the frame is consumed.  A 0 is returned if
609  * the frame should be processed normally by the caller.
610  */
611 int
612 ieee80211_ampdu_reorder(struct ieee80211_node *ni, struct mbuf *m)
613 {
614 #define	IEEE80211_FC0_QOSDATA \
615 	(IEEE80211_FC0_TYPE_DATA|IEEE80211_FC0_SUBTYPE_QOS|IEEE80211_FC0_VERSION_0)
616 #define	PROCESS		0	/* caller should process frame */
617 #define	CONSUMED	1	/* frame consumed, caller does nothing */
618 	struct ieee80211vap *vap = ni->ni_vap;
619 	struct ieee80211_qosframe *wh;
620 	struct ieee80211_rx_ampdu *rap;
621 	ieee80211_seq rxseq;
622 	uint8_t tid;
623 	int off;
624 
625 	KASSERT((m->m_flags & (M_AMPDU | M_AMPDU_MPDU)) == M_AMPDU,
626 	    ("!a-mpdu or already re-ordered, flags 0x%x", m->m_flags));
627 	KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT sta"));
628 
629 	/* NB: m_len known to be sufficient */
630 	wh = mtod(m, struct ieee80211_qosframe *);
631 	if (wh->i_fc[0] != IEEE80211_FC0_QOSDATA) {
632 		/*
633 		 * Not QoS data, shouldn't get here but just
634 		 * return it to the caller for processing.
635 		 */
636 		return PROCESS;
637 	}
638 	if (IEEE80211_IS_DSTODS(wh))
639 		tid = ((struct ieee80211_qosframe_addr4 *)wh)->i_qos[0];
640 	else
641 		tid = wh->i_qos[0];
642 	tid &= IEEE80211_QOS_TID;
643 	rap = &ni->ni_rx_ampdu[tid];
644 	if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
645 		/*
646 		 * No ADDBA request yet, don't touch.
647 		 */
648 		return PROCESS;
649 	}
650 	rxseq = le16toh(*(uint16_t *)wh->i_seq);
651 	if ((rxseq & IEEE80211_SEQ_FRAG_MASK) != 0) {
652 		/*
653 		 * Fragments are not allowed; toss.
654 		 */
655 		IEEE80211_DISCARD_MAC(vap,
656 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
657 		    "A-MPDU", "fragment, rxseq 0x%x tid %u%s", rxseq, tid,
658 		    wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
659 		vap->iv_stats.is_ampdu_rx_drop++;
660 		IEEE80211_NODE_STAT(ni, rx_drop);
661 		m_freem(m);
662 		return CONSUMED;
663 	}
664 	rxseq >>= IEEE80211_SEQ_SEQ_SHIFT;
665 	rap->rxa_nframes++;
666 again:
667 	if (rxseq == rap->rxa_start) {
668 		/*
669 		 * First frame in window.
670 		 */
671 		if (rap->rxa_qframes != 0) {
672 			/*
673 			 * Dispatch as many packets as we can.
674 			 */
675 			KASSERT(rap->rxa_m[0] == NULL, ("unexpected dup"));
676 			ampdu_dispatch(ni, m);
677 			ampdu_rx_dispatch(rap, ni);
678 			return CONSUMED;
679 		} else {
680 			/*
681 			 * In order; advance window and notify
682 			 * caller to dispatch directly.
683 			 */
684 			rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
685 			return PROCESS;
686 		}
687 	}
688 	/*
689 	 * Frame is out of order; store if in the BA window.
690 	 */
691 	/* calculate offset in BA window */
692 	off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
693 	if (off < rap->rxa_wnd) {
694 		/*
695 		 * Common case (hopefully): in the BA window.
696 		 * Sec 9.10.7.6.2 a) (p.137)
697 		 */
698 #ifdef IEEE80211_AMPDU_AGE
699 		/*
700 		 * Check for frames sitting too long in the reorder queue.
701 		 * This should only ever happen if frames are not delivered
702 		 * without the sender otherwise notifying us (e.g. with a
703 		 * BAR to move the window).  Typically this happens because
704 		 * of vendor bugs that cause the sequence number to jump.
705 		 * When this happens we get a gap in the reorder queue that
706 		 * leaves frame sitting on the queue until they get pushed
707 		 * out due to window moves.  When the vendor does not send
708 		 * BAR this move only happens due to explicit packet sends
709 		 *
710 		 * NB: we only track the time of the oldest frame in the
711 		 * reorder q; this means that if we flush we might push
712 		 * frames that still "new"; if this happens then subsequent
713 		 * frames will result in BA window moves which cost something
714 		 * but is still better than a big throughput dip.
715 		 */
716 		if (rap->rxa_qframes != 0) {
717 			/* XXX honor batimeout? */
718 			if (ticks - rap->rxa_age > ieee80211_ampdu_age) {
719 				/*
720 				 * Too long since we received the first
721 				 * frame; flush the reorder buffer.
722 				 */
723 				if (rap->rxa_qframes != 0) {
724 					vap->iv_stats.is_ampdu_rx_age +=
725 					    rap->rxa_qframes;
726 					ampdu_rx_flush(ni, rap);
727 				}
728 				rap->rxa_start = IEEE80211_SEQ_INC(rxseq);
729 				return PROCESS;
730 			}
731 		} else {
732 			/*
733 			 * First frame, start aging timer.
734 			 */
735 			rap->rxa_age = ticks;
736 		}
737 #endif /* IEEE80211_AMPDU_AGE */
738 		/* save packet */
739 		if (rap->rxa_m[off] == NULL) {
740 			rap->rxa_m[off] = m;
741 			rap->rxa_qframes++;
742 			rap->rxa_qbytes += m->m_pkthdr.len;
743 			vap->iv_stats.is_ampdu_rx_reorder++;
744 		} else {
745 			IEEE80211_DISCARD_MAC(vap,
746 			    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N,
747 			    ni->ni_macaddr, "a-mpdu duplicate",
748 			    "seqno %u tid %u BA win <%u:%u>",
749 			    rxseq, tid, rap->rxa_start,
750 			    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1));
751 			vap->iv_stats.is_rx_dup++;
752 			IEEE80211_NODE_STAT(ni, rx_dup);
753 			m_freem(m);
754 		}
755 		return CONSUMED;
756 	}
757 	if (off < IEEE80211_SEQ_BA_RANGE) {
758 		/*
759 		 * Outside the BA window, but within range;
760 		 * flush the reorder q and move the window.
761 		 * Sec 9.10.7.6.2 b) (p.138)
762 		 */
763 		IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
764 		    "move BA win <%u:%u> (%u frames) rxseq %u tid %u",
765 		    rap->rxa_start,
766 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
767 		    rap->rxa_qframes, rxseq, tid);
768 		vap->iv_stats.is_ampdu_rx_move++;
769 
770 		/*
771 		 * The spec says to flush frames up to but not including:
772 		 * 	WinStart_B = rxseq - rap->rxa_wnd + 1
773 		 * Then insert the frame or notify the caller to process
774 		 * it immediately.  We can safely do this by just starting
775 		 * over again because we know the frame will now be within
776 		 * the BA window.
777 		 */
778 		/* NB: rxa_wnd known to be >0 */
779 		ampdu_rx_flush_upto(ni, rap,
780 		    IEEE80211_SEQ_SUB(rxseq, rap->rxa_wnd-1));
781 		goto again;
782 	} else {
783 		/*
784 		 * Outside the BA window and out of range; toss.
785 		 * Sec 9.10.7.6.2 c) (p.138)
786 		 */
787 		IEEE80211_DISCARD_MAC(vap,
788 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
789 		    "MPDU", "BA win <%u:%u> (%u frames) rxseq %u tid %u%s",
790 		    rap->rxa_start,
791 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
792 		    rap->rxa_qframes, rxseq, tid,
793 		    wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
794 		vap->iv_stats.is_ampdu_rx_drop++;
795 		IEEE80211_NODE_STAT(ni, rx_drop);
796 		m_freem(m);
797 		return CONSUMED;
798 	}
799 #undef CONSUMED
800 #undef PROCESS
801 #undef IEEE80211_FC0_QOSDATA
802 }
803 
804 /*
805  * Process a BAR ctl frame.  Dispatch all frames up to
806  * the sequence number of the frame.  If this frame is
807  * out of range it's discarded.
808  */
809 void
810 ieee80211_recv_bar(struct ieee80211_node *ni, struct mbuf *m0)
811 {
812 	struct ieee80211vap *vap = ni->ni_vap;
813 	struct ieee80211_frame_bar *wh;
814 	struct ieee80211_rx_ampdu *rap;
815 	ieee80211_seq rxseq;
816 	int tid, off;
817 
818 	if (!ieee80211_recv_bar_ena) {
819 #if 0
820 		IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_11N,
821 		    ni->ni_macaddr, "BAR", "%s", "processing disabled");
822 #endif
823 		vap->iv_stats.is_ampdu_bar_bad++;
824 		return;
825 	}
826 	wh = mtod(m0, struct ieee80211_frame_bar *);
827 	/* XXX check basic BAR */
828 	tid = MS(le16toh(wh->i_ctl), IEEE80211_BAR_TID);
829 	rap = &ni->ni_rx_ampdu[tid];
830 	if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
831 		/*
832 		 * No ADDBA request yet, don't touch.
833 		 */
834 		IEEE80211_DISCARD_MAC(vap,
835 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N,
836 		    ni->ni_macaddr, "BAR", "no BA stream, tid %u", tid);
837 		vap->iv_stats.is_ampdu_bar_bad++;
838 		return;
839 	}
840 	vap->iv_stats.is_ampdu_bar_rx++;
841 	rxseq = le16toh(wh->i_seq) >> IEEE80211_SEQ_SEQ_SHIFT;
842 	if (rxseq == rap->rxa_start)
843 		return;
844 	/* calculate offset in BA window */
845 	off = IEEE80211_SEQ_SUB(rxseq, rap->rxa_start);
846 	if (off < IEEE80211_SEQ_BA_RANGE) {
847 		/*
848 		 * Flush the reorder q up to rxseq and move the window.
849 		 * Sec 9.10.7.6.3 a) (p.138)
850 		 */
851 		IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
852 		    "BAR moves BA win <%u:%u> (%u frames) rxseq %u tid %u",
853 		    rap->rxa_start,
854 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
855 		    rap->rxa_qframes, rxseq, tid);
856 		vap->iv_stats.is_ampdu_bar_move++;
857 
858 		ampdu_rx_flush_upto(ni, rap, rxseq);
859 		if (off >= rap->rxa_wnd) {
860 			/*
861 			 * BAR specifies a window start to the right of BA
862 			 * window; we must move it explicitly since
863 			 * ampdu_rx_flush_upto will not.
864 			 */
865 			rap->rxa_start = rxseq;
866 		}
867 	} else {
868 		/*
869 		 * Out of range; toss.
870 		 * Sec 9.10.7.6.3 b) (p.138)
871 		 */
872 		IEEE80211_DISCARD_MAC(vap,
873 		    IEEE80211_MSG_INPUT | IEEE80211_MSG_11N, ni->ni_macaddr,
874 		    "BAR", "BA win <%u:%u> (%u frames) rxseq %u tid %u%s",
875 		    rap->rxa_start,
876 		    IEEE80211_SEQ_ADD(rap->rxa_start, rap->rxa_wnd-1),
877 		    rap->rxa_qframes, rxseq, tid,
878 		    wh->i_fc[1] & IEEE80211_FC1_RETRY ? " (retransmit)" : "");
879 		vap->iv_stats.is_ampdu_bar_oow++;
880 		IEEE80211_NODE_STAT(ni, rx_drop);
881 	}
882 }
883 
884 /*
885  * Setup HT-specific state in a node.  Called only
886  * when HT use is negotiated so we don't do extra
887  * work for temporary and/or legacy sta's.
888  */
889 void
890 ieee80211_ht_node_init(struct ieee80211_node *ni)
891 {
892 	struct ieee80211_tx_ampdu *tap;
893 	int ac;
894 
895 	if (ni->ni_flags & IEEE80211_NODE_HT) {
896 		/*
897 		 * Clean AMPDU state on re-associate.  This handles the case
898 		 * where a station leaves w/o notifying us and then returns
899 		 * before node is reaped for inactivity.
900 		 */
901 		ieee80211_ht_node_cleanup(ni);
902 	}
903 	for (ac = 0; ac < WME_NUM_AC; ac++) {
904 		tap = &ni->ni_tx_ampdu[ac];
905 		tap->txa_ac = ac;
906 		tap->txa_ni = ni;
907 		/* NB: further initialization deferred */
908 	}
909 	ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
910 }
911 
912 /*
913  * Cleanup HT-specific state in a node.  Called only
914  * when HT use has been marked.
915  */
916 void
917 ieee80211_ht_node_cleanup(struct ieee80211_node *ni)
918 {
919 	struct ieee80211com *ic = ni->ni_ic;
920 	int i;
921 
922 	KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT node"));
923 
924 	/* XXX optimize this */
925 	for (i = 0; i < WME_NUM_AC; i++) {
926 		struct ieee80211_tx_ampdu *tap = &ni->ni_tx_ampdu[i];
927 		if (tap->txa_flags & IEEE80211_AGGR_SETUP)
928 			ampdu_tx_stop(tap);
929 	}
930 	for (i = 0; i < WME_NUM_TID; i++)
931 		ic->ic_ampdu_rx_stop(ni, &ni->ni_rx_ampdu[i]);
932 
933 	ni->ni_htcap = 0;
934 	ni->ni_flags &= ~IEEE80211_NODE_HT_ALL;
935 }
936 
937 /*
938  * Age out HT resources for a station.
939  */
940 void
941 ieee80211_ht_node_age(struct ieee80211_node *ni)
942 {
943 #ifdef IEEE80211_AMPDU_AGE
944 	struct ieee80211vap *vap = ni->ni_vap;
945 	uint8_t tid;
946 #endif
947 
948 	KASSERT(ni->ni_flags & IEEE80211_NODE_HT, ("not an HT sta"));
949 
950 #ifdef IEEE80211_AMPDU_AGE
951 	for (tid = 0; tid < WME_NUM_TID; tid++) {
952 		struct ieee80211_rx_ampdu *rap;
953 
954 		rap = &ni->ni_rx_ampdu[tid];
955 		if ((rap->rxa_flags & IEEE80211_AGGR_XCHGPEND) == 0)
956 			continue;
957 		if (rap->rxa_qframes == 0)
958 			continue;
959 		/*
960 		 * Check for frames sitting too long in the reorder queue.
961 		 * See above for more details on what's happening here.
962 		 */
963 		/* XXX honor batimeout? */
964 		if (ticks - rap->rxa_age > ieee80211_ampdu_age) {
965 			/*
966 			 * Too long since we received the first
967 			 * frame; flush the reorder buffer.
968 			 */
969 			vap->iv_stats.is_ampdu_rx_age += rap->rxa_qframes;
970 			ampdu_rx_flush(ni, rap);
971 		}
972 	}
973 #endif /* IEEE80211_AMPDU_AGE */
974 }
975 
976 static struct ieee80211_channel *
977 findhtchan(struct ieee80211com *ic, struct ieee80211_channel *c, int htflags)
978 {
979 	return ieee80211_find_channel(ic, c->ic_freq,
980 	    (c->ic_flags &~ IEEE80211_CHAN_HT) | htflags);
981 }
982 
983 /*
984  * Adjust a channel to be HT/non-HT according to the vap's configuration.
985  */
986 struct ieee80211_channel *
987 ieee80211_ht_adjust_channel(struct ieee80211com *ic,
988 	struct ieee80211_channel *chan, int flags)
989 {
990 	struct ieee80211_channel *c;
991 
992 	if (flags & IEEE80211_FHT_HT) {
993 		/* promote to HT if possible */
994 		if (flags & IEEE80211_FHT_USEHT40) {
995 			if (!IEEE80211_IS_CHAN_HT40(chan)) {
996 				/* NB: arbitrarily pick ht40+ over ht40- */
997 				c = findhtchan(ic, chan, IEEE80211_CHAN_HT40U);
998 				if (c == NULL)
999 					c = findhtchan(ic, chan,
1000 						IEEE80211_CHAN_HT40D);
1001 				if (c == NULL)
1002 					c = findhtchan(ic, chan,
1003 						IEEE80211_CHAN_HT20);
1004 				if (c != NULL)
1005 					chan = c;
1006 			}
1007 		} else if (!IEEE80211_IS_CHAN_HT20(chan)) {
1008 			c = findhtchan(ic, chan, IEEE80211_CHAN_HT20);
1009 			if (c != NULL)
1010 				chan = c;
1011 		}
1012 	} else if (IEEE80211_IS_CHAN_HT(chan)) {
1013 		/* demote to legacy, HT use is disabled */
1014 		c = ieee80211_find_channel(ic, chan->ic_freq,
1015 		    chan->ic_flags &~ IEEE80211_CHAN_HT);
1016 		if (c != NULL)
1017 			chan = c;
1018 	}
1019 	return chan;
1020 }
1021 
1022 /*
1023  * Setup HT-specific state for a legacy WDS peer.
1024  */
1025 void
1026 ieee80211_ht_wds_init(struct ieee80211_node *ni)
1027 {
1028 	struct ieee80211vap *vap = ni->ni_vap;
1029 	struct ieee80211_tx_ampdu *tap;
1030 	int ac;
1031 
1032 	KASSERT(vap->iv_flags_ht & IEEE80211_FHT_HT, ("no HT requested"));
1033 
1034 	/* XXX check scan cache in case peer has an ap and we have info */
1035 	/*
1036 	 * If setup with a legacy channel; locate an HT channel.
1037 	 * Otherwise if the inherited channel (from a companion
1038 	 * AP) is suitable use it so we use the same location
1039 	 * for the extension channel).
1040 	 */
1041 	ni->ni_chan = ieee80211_ht_adjust_channel(ni->ni_ic,
1042 	    ni->ni_chan, ieee80211_htchanflags(ni->ni_chan));
1043 
1044 	ni->ni_htcap = 0;
1045 	if (vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20)
1046 		ni->ni_htcap |= IEEE80211_HTCAP_SHORTGI20;
1047 	if (IEEE80211_IS_CHAN_HT40(ni->ni_chan)) {
1048 		ni->ni_htcap |= IEEE80211_HTCAP_CHWIDTH40;
1049 		ni->ni_chw = 40;
1050 		if (IEEE80211_IS_CHAN_HT40U(ni->ni_chan))
1051 			ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_ABOVE;
1052 		else if (IEEE80211_IS_CHAN_HT40D(ni->ni_chan))
1053 			ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_BELOW;
1054 		if (vap->iv_flags_ht & IEEE80211_FHT_SHORTGI40)
1055 			ni->ni_htcap |= IEEE80211_HTCAP_SHORTGI40;
1056 	} else {
1057 		ni->ni_chw = 20;
1058 		ni->ni_ht2ndchan = IEEE80211_HTINFO_2NDCHAN_NONE;
1059 	}
1060 	ni->ni_htctlchan = ni->ni_chan->ic_ieee;
1061 	if (vap->iv_flags_ht & IEEE80211_FHT_RIFS)
1062 		ni->ni_flags |= IEEE80211_NODE_RIFS;
1063 	/* XXX does it make sense to enable SMPS? */
1064 
1065 	ni->ni_htopmode = 0;		/* XXX need protection state */
1066 	ni->ni_htstbc = 0;		/* XXX need info */
1067 
1068 	for (ac = 0; ac < WME_NUM_AC; ac++) {
1069 		tap = &ni->ni_tx_ampdu[ac];
1070 		tap->txa_ac = ac;
1071 	}
1072 	/* NB: AMPDU tx/rx governed by IEEE80211_FHT_AMPDU_{TX,RX} */
1073 	ni->ni_flags |= IEEE80211_NODE_HT | IEEE80211_NODE_AMPDU;
1074 }
1075 
1076 /*
1077  * Notify hostap vaps of a change in the HTINFO ie.
1078  */
1079 static void
1080 htinfo_notify(struct ieee80211com *ic)
1081 {
1082 	struct ieee80211vap *vap;
1083 	int first = 1;
1084 
1085 	IEEE80211_LOCK_ASSERT(ic);
1086 
1087 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
1088 		if (vap->iv_opmode != IEEE80211_M_HOSTAP)
1089 			continue;
1090 		if (vap->iv_state != IEEE80211_S_RUN ||
1091 		    !IEEE80211_IS_CHAN_HT(vap->iv_bss->ni_chan))
1092 			continue;
1093 		if (first) {
1094 			IEEE80211_NOTE(vap,
1095 			    IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N,
1096 			    vap->iv_bss,
1097 			    "HT bss occupancy change: %d sta, %d ht, "
1098 			    "%d ht40%s, HT protmode now 0x%x"
1099 			    , ic->ic_sta_assoc
1100 			    , ic->ic_ht_sta_assoc
1101 			    , ic->ic_ht40_sta_assoc
1102 			    , (ic->ic_flags_ht & IEEE80211_FHT_NONHT_PR) ?
1103 				 ", non-HT sta present" : ""
1104 			    , ic->ic_curhtprotmode);
1105 			first = 0;
1106 		}
1107 		ieee80211_beacon_notify(vap, IEEE80211_BEACON_HTINFO);
1108 	}
1109 }
1110 
1111 /*
1112  * Calculate HT protection mode from current
1113  * state and handle updates.
1114  */
1115 static void
1116 htinfo_update(struct ieee80211com *ic)
1117 {
1118 	uint8_t protmode;
1119 
1120 	if (ic->ic_sta_assoc != ic->ic_ht_sta_assoc) {
1121 		protmode = IEEE80211_HTINFO_OPMODE_MIXED
1122 			 | IEEE80211_HTINFO_NONHT_PRESENT;
1123 	} else if (ic->ic_flags_ht & IEEE80211_FHT_NONHT_PR) {
1124 		protmode = IEEE80211_HTINFO_OPMODE_PROTOPT
1125 			 | IEEE80211_HTINFO_NONHT_PRESENT;
1126 	} else if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
1127 	    IEEE80211_IS_CHAN_HT40(ic->ic_bsschan) &&
1128 	    ic->ic_sta_assoc != ic->ic_ht40_sta_assoc) {
1129 		protmode = IEEE80211_HTINFO_OPMODE_HT20PR;
1130 	} else {
1131 		protmode = IEEE80211_HTINFO_OPMODE_PURE;
1132 	}
1133 	if (protmode != ic->ic_curhtprotmode) {
1134 		ic->ic_curhtprotmode = protmode;
1135 		htinfo_notify(ic);
1136 	}
1137 }
1138 
1139 /*
1140  * Handle an HT station joining a BSS.
1141  */
1142 void
1143 ieee80211_ht_node_join(struct ieee80211_node *ni)
1144 {
1145 	struct ieee80211com *ic = ni->ni_ic;
1146 
1147 	IEEE80211_LOCK_ASSERT(ic);
1148 
1149 	if (ni->ni_flags & IEEE80211_NODE_HT) {
1150 		ic->ic_ht_sta_assoc++;
1151 		if (ni->ni_chw == 40)
1152 			ic->ic_ht40_sta_assoc++;
1153 	}
1154 	htinfo_update(ic);
1155 }
1156 
1157 /*
1158  * Handle an HT station leaving a BSS.
1159  */
1160 void
1161 ieee80211_ht_node_leave(struct ieee80211_node *ni)
1162 {
1163 	struct ieee80211com *ic = ni->ni_ic;
1164 
1165 	IEEE80211_LOCK_ASSERT(ic);
1166 
1167 	if (ni->ni_flags & IEEE80211_NODE_HT) {
1168 		ic->ic_ht_sta_assoc--;
1169 		if (ni->ni_chw == 40)
1170 			ic->ic_ht40_sta_assoc--;
1171 	}
1172 	htinfo_update(ic);
1173 }
1174 
1175 /*
1176  * Public version of htinfo_update; used for processing
1177  * beacon frames from overlapping bss.
1178  *
1179  * Caller can specify either IEEE80211_HTINFO_OPMODE_MIXED
1180  * (on receipt of a beacon that advertises MIXED) or
1181  * IEEE80211_HTINFO_OPMODE_PROTOPT (on receipt of a beacon
1182  * from an overlapping legacy bss).  We treat MIXED with
1183  * a higher precedence than PROTOPT (i.e. we will not change
1184  * change PROTOPT -> MIXED; only MIXED -> PROTOPT).  This
1185  * corresponds to how we handle things in htinfo_update.
1186  */
1187 void
1188 ieee80211_htprot_update(struct ieee80211com *ic, int protmode)
1189 {
1190 #define	OPMODE(x)	SM(x, IEEE80211_HTINFO_OPMODE)
1191 	IEEE80211_LOCK(ic);
1192 
1193 	/* track non-HT station presence */
1194 	KASSERT(protmode & IEEE80211_HTINFO_NONHT_PRESENT,
1195 	    ("protmode 0x%x", protmode));
1196 	ic->ic_flags_ht |= IEEE80211_FHT_NONHT_PR;
1197 	ic->ic_lastnonht = ticks;
1198 
1199 	if (protmode != ic->ic_curhtprotmode &&
1200 	    (OPMODE(ic->ic_curhtprotmode) != IEEE80211_HTINFO_OPMODE_MIXED ||
1201 	     OPMODE(protmode) == IEEE80211_HTINFO_OPMODE_PROTOPT)) {
1202 		/* push beacon update */
1203 		ic->ic_curhtprotmode = protmode;
1204 		htinfo_notify(ic);
1205 	}
1206 	IEEE80211_UNLOCK(ic);
1207 #undef OPMODE
1208 }
1209 
1210 /*
1211  * Time out presence of an overlapping bss with non-HT
1212  * stations.  When operating in hostap mode we listen for
1213  * beacons from other stations and if we identify a non-HT
1214  * station is present we update the opmode field of the
1215  * HTINFO ie.  To identify when all non-HT stations are
1216  * gone we time out this condition.
1217  */
1218 void
1219 ieee80211_ht_timeout(struct ieee80211com *ic)
1220 {
1221 	IEEE80211_LOCK_ASSERT(ic);
1222 
1223 	if ((ic->ic_flags_ht & IEEE80211_FHT_NONHT_PR) &&
1224 	    time_after(ticks, ic->ic_lastnonht + IEEE80211_NONHT_PRESENT_AGE)) {
1225 #if 0
1226 		IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
1227 		    "%s", "time out non-HT STA present on channel");
1228 #endif
1229 		ic->ic_flags_ht &= ~IEEE80211_FHT_NONHT_PR;
1230 		htinfo_update(ic);
1231 	}
1232 }
1233 
1234 /* unalligned little endian access */
1235 #define LE_READ_2(p)					\
1236 	((uint16_t)					\
1237 	 ((((const uint8_t *)(p))[0]      ) |		\
1238 	  (((const uint8_t *)(p))[1] <<  8)))
1239 
1240 /*
1241  * Process an 802.11n HT capabilities ie.
1242  */
1243 void
1244 ieee80211_parse_htcap(struct ieee80211_node *ni, const uint8_t *ie)
1245 {
1246 	if (ie[0] == IEEE80211_ELEMID_VENDOR) {
1247 		/*
1248 		 * Station used Vendor OUI ie to associate;
1249 		 * mark the node so when we respond we'll use
1250 		 * the Vendor OUI's and not the standard ie's.
1251 		 */
1252 		ni->ni_flags |= IEEE80211_NODE_HTCOMPAT;
1253 		ie += 4;
1254 	} else
1255 		ni->ni_flags &= ~IEEE80211_NODE_HTCOMPAT;
1256 
1257 	ni->ni_htcap = LE_READ_2(ie +
1258 		__offsetof(struct ieee80211_ie_htcap, hc_cap));
1259 	ni->ni_htparam = ie[__offsetof(struct ieee80211_ie_htcap, hc_param)];
1260 }
1261 
1262 static void
1263 htinfo_parse(struct ieee80211_node *ni,
1264 	const struct ieee80211_ie_htinfo *htinfo)
1265 {
1266 	uint16_t w;
1267 
1268 	ni->ni_htctlchan = htinfo->hi_ctrlchannel;
1269 	ni->ni_ht2ndchan = SM(htinfo->hi_byte1, IEEE80211_HTINFO_2NDCHAN);
1270 	w = LE_READ_2(&htinfo->hi_byte2);
1271 	ni->ni_htopmode = SM(w, IEEE80211_HTINFO_OPMODE);
1272 	w = LE_READ_2(&htinfo->hi_byte45);
1273 	ni->ni_htstbc = SM(w, IEEE80211_HTINFO_BASIC_STBCMCS);
1274 }
1275 
1276 /*
1277  * Parse an 802.11n HT info ie and save useful information
1278  * to the node state.  Note this does not effect any state
1279  * changes such as for channel width change.
1280  */
1281 void
1282 ieee80211_parse_htinfo(struct ieee80211_node *ni, const uint8_t *ie)
1283 {
1284 	if (ie[0] == IEEE80211_ELEMID_VENDOR)
1285 		ie += 4;
1286 	htinfo_parse(ni, (const struct ieee80211_ie_htinfo *) ie);
1287 }
1288 
1289 /*
1290  * Handle 11n channel switch.  Use the received HT ie's to
1291  * identify the right channel to use.  If we cannot locate it
1292  * in the channel table then fallback to legacy operation.
1293  * Note that we use this information to identify the node's
1294  * channel only; the caller is responsible for insuring any
1295  * required channel change is done (e.g. in sta mode when
1296  * parsing the contents of a beacon frame).
1297  */
1298 static void
1299 htinfo_update_chw(struct ieee80211_node *ni, int htflags)
1300 {
1301 	struct ieee80211com *ic = ni->ni_ic;
1302 	struct ieee80211_channel *c;
1303 	int chanflags;
1304 
1305 	chanflags = (ni->ni_chan->ic_flags &~ IEEE80211_CHAN_HT) | htflags;
1306 	if (chanflags != ni->ni_chan->ic_flags) {
1307 		/* XXX not right for ht40- */
1308 		c = ieee80211_find_channel(ic, ni->ni_chan->ic_freq, chanflags);
1309 		if (c == NULL && (htflags & IEEE80211_CHAN_HT40)) {
1310 			/*
1311 			 * No HT40 channel entry in our table; fall back
1312 			 * to HT20 operation.  This should not happen.
1313 			 */
1314 			c = findhtchan(ic, ni->ni_chan, IEEE80211_CHAN_HT20);
1315 #if 0
1316 			IEEE80211_NOTE(ni->ni_vap,
1317 			    IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N, ni,
1318 			    "no HT40 channel (freq %u), falling back to HT20",
1319 			    ni->ni_chan->ic_freq);
1320 #endif
1321 			/* XXX stat */
1322 		}
1323 		if (c != NULL && c != ni->ni_chan) {
1324 			IEEE80211_NOTE(ni->ni_vap,
1325 			    IEEE80211_MSG_ASSOC | IEEE80211_MSG_11N, ni,
1326 			    "switch station to HT%d channel %u/0x%x",
1327 			    IEEE80211_IS_CHAN_HT40(c) ? 40 : 20,
1328 			    c->ic_freq, c->ic_flags);
1329 			ni->ni_chan = c;
1330 		}
1331 		/* NB: caller responsible for forcing any channel change */
1332 	}
1333 	/* update node's tx channel width */
1334 	ni->ni_chw = IEEE80211_IS_CHAN_HT40(ni->ni_chan)? 40 : 20;
1335 }
1336 
1337 /*
1338  * Update 11n MIMO PS state according to received htcap.
1339  */
1340 static __inline int
1341 htcap_update_mimo_ps(struct ieee80211_node *ni)
1342 {
1343 	uint16_t oflags = ni->ni_flags;
1344 
1345 	switch (ni->ni_htcap & IEEE80211_HTCAP_SMPS) {
1346 	case IEEE80211_HTCAP_SMPS_DYNAMIC:
1347 		ni->ni_flags |= IEEE80211_NODE_MIMO_PS;
1348 		ni->ni_flags |= IEEE80211_NODE_MIMO_RTS;
1349 		break;
1350 	case IEEE80211_HTCAP_SMPS_ENA:
1351 		ni->ni_flags |= IEEE80211_NODE_MIMO_PS;
1352 		ni->ni_flags &= ~IEEE80211_NODE_MIMO_RTS;
1353 		break;
1354 	case IEEE80211_HTCAP_SMPS_OFF:
1355 	default:		/* disable on rx of reserved value */
1356 		ni->ni_flags &= ~IEEE80211_NODE_MIMO_PS;
1357 		ni->ni_flags &= ~IEEE80211_NODE_MIMO_RTS;
1358 		break;
1359 	}
1360 	return (oflags ^ ni->ni_flags);
1361 }
1362 
1363 /*
1364  * Update short GI state according to received htcap
1365  * and local settings.
1366  */
1367 static __inline void
1368 htcap_update_shortgi(struct ieee80211_node *ni)
1369 {
1370 	struct ieee80211vap *vap = ni->ni_vap;
1371 
1372 	ni->ni_flags &= ~(IEEE80211_NODE_SGI20|IEEE80211_NODE_SGI40);
1373 	if ((ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20) &&
1374 	    (vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20))
1375 		ni->ni_flags |= IEEE80211_NODE_SGI20;
1376 	if ((ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40) &&
1377 	    (vap->iv_flags_ht & IEEE80211_FHT_SHORTGI40))
1378 		ni->ni_flags |= IEEE80211_NODE_SGI40;
1379 }
1380 
1381 /*
1382  * Parse and update HT-related state extracted from
1383  * the HT cap and info ie's.
1384  */
1385 void
1386 ieee80211_ht_updateparams(struct ieee80211_node *ni,
1387 	const uint8_t *htcapie, const uint8_t *htinfoie)
1388 {
1389 	struct ieee80211vap *vap = ni->ni_vap;
1390 	const struct ieee80211_ie_htinfo *htinfo;
1391 	int htflags;
1392 
1393 	ieee80211_parse_htcap(ni, htcapie);
1394 	if (vap->iv_htcaps & IEEE80211_HTCAP_SMPS)
1395 		htcap_update_mimo_ps(ni);
1396 	htcap_update_shortgi(ni);
1397 
1398 	if (htinfoie[0] == IEEE80211_ELEMID_VENDOR)
1399 		htinfoie += 4;
1400 	htinfo = (const struct ieee80211_ie_htinfo *) htinfoie;
1401 	htinfo_parse(ni, htinfo);
1402 
1403 	htflags = (vap->iv_flags_ht & IEEE80211_FHT_HT) ?
1404 	    IEEE80211_CHAN_HT20 : 0;
1405 	/* NB: honor operating mode constraint */
1406 	if ((htinfo->hi_byte1 & IEEE80211_HTINFO_TXWIDTH_2040) &&
1407 	    (vap->iv_flags_ht & IEEE80211_FHT_USEHT40)) {
1408 		if (ni->ni_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_ABOVE)
1409 			htflags = IEEE80211_CHAN_HT40U;
1410 		else if (ni->ni_ht2ndchan == IEEE80211_HTINFO_2NDCHAN_BELOW)
1411 			htflags = IEEE80211_CHAN_HT40D;
1412 	}
1413 	htinfo_update_chw(ni, htflags);
1414 
1415 	if ((htinfo->hi_byte1 & IEEE80211_HTINFO_RIFSMODE_PERM) &&
1416 	    (vap->iv_flags_ht & IEEE80211_FHT_RIFS))
1417 		ni->ni_flags |= IEEE80211_NODE_RIFS;
1418 	else
1419 		ni->ni_flags &= ~IEEE80211_NODE_RIFS;
1420 }
1421 
1422 /*
1423  * Parse and update HT-related state extracted from the HT cap ie
1424  * for a station joining an HT BSS.
1425  */
1426 void
1427 ieee80211_ht_updatehtcap(struct ieee80211_node *ni, const uint8_t *htcapie)
1428 {
1429 	struct ieee80211vap *vap = ni->ni_vap;
1430 	int htflags;
1431 
1432 	ieee80211_parse_htcap(ni, htcapie);
1433 	if (vap->iv_htcaps & IEEE80211_HTCAP_SMPS)
1434 		htcap_update_mimo_ps(ni);
1435 	htcap_update_shortgi(ni);
1436 
1437 	/* NB: honor operating mode constraint */
1438 	/* XXX 40 MHZ intolerant */
1439 	htflags = (vap->iv_flags_ht & IEEE80211_FHT_HT) ?
1440 	    IEEE80211_CHAN_HT20 : 0;
1441 	if ((ni->ni_htcap & IEEE80211_HTCAP_CHWIDTH40) &&
1442 	    (vap->iv_flags_ht & IEEE80211_FHT_USEHT40)) {
1443 		if (IEEE80211_IS_CHAN_HT40U(vap->iv_bss->ni_chan))
1444 			htflags = IEEE80211_CHAN_HT40U;
1445 		else if (IEEE80211_IS_CHAN_HT40D(vap->iv_bss->ni_chan))
1446 			htflags = IEEE80211_CHAN_HT40D;
1447 	}
1448 	htinfo_update_chw(ni, htflags);
1449 }
1450 
1451 /*
1452  * Install received HT rate set by parsing the HT cap ie.
1453  */
1454 int
1455 ieee80211_setup_htrates(struct ieee80211_node *ni, const uint8_t *ie, int flags)
1456 {
1457 	struct ieee80211vap *vap = ni->ni_vap;
1458 	const struct ieee80211_ie_htcap *htcap;
1459 	struct ieee80211_htrateset *rs;
1460 	int i;
1461 
1462 	rs = &ni->ni_htrates;
1463 	memset(rs, 0, sizeof(*rs));
1464 	if (ie != NULL) {
1465 		if (ie[0] == IEEE80211_ELEMID_VENDOR)
1466 			ie += 4;
1467 		htcap = (const struct ieee80211_ie_htcap *) ie;
1468 		for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
1469 			if (isclr(htcap->hc_mcsset, i))
1470 				continue;
1471 			if (rs->rs_nrates == IEEE80211_HTRATE_MAXSIZE) {
1472 				IEEE80211_NOTE(vap,
1473 				    IEEE80211_MSG_XRATE | IEEE80211_MSG_11N, ni,
1474 				    "WARNING, HT rate set too large; only "
1475 				    "using %u rates", IEEE80211_HTRATE_MAXSIZE);
1476 				vap->iv_stats.is_rx_rstoobig++;
1477 				break;
1478 			}
1479 			rs->rs_rates[rs->rs_nrates++] = i;
1480 		}
1481 	}
1482 	return ieee80211_fix_rate(ni, (struct ieee80211_rateset *) rs, flags);
1483 }
1484 
1485 /*
1486  * Mark rates in a node's HT rate set as basic according
1487  * to the information in the supplied HT info ie.
1488  */
1489 void
1490 ieee80211_setup_basic_htrates(struct ieee80211_node *ni, const uint8_t *ie)
1491 {
1492 	const struct ieee80211_ie_htinfo *htinfo;
1493 	struct ieee80211_htrateset *rs;
1494 	int i, j;
1495 
1496 	if (ie[0] == IEEE80211_ELEMID_VENDOR)
1497 		ie += 4;
1498 	htinfo = (const struct ieee80211_ie_htinfo *) ie;
1499 	rs = &ni->ni_htrates;
1500 	if (rs->rs_nrates == 0) {
1501 		IEEE80211_NOTE(ni->ni_vap,
1502 		    IEEE80211_MSG_XRATE | IEEE80211_MSG_11N, ni,
1503 		    "%s", "WARNING, empty HT rate set");
1504 		return;
1505 	}
1506 	for (i = 0; i < IEEE80211_HTRATE_MAXSIZE; i++) {
1507 		if (isclr(htinfo->hi_basicmcsset, i))
1508 			continue;
1509 		for (j = 0; j < rs->rs_nrates; j++)
1510 			if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == i)
1511 				rs->rs_rates[j] |= IEEE80211_RATE_BASIC;
1512 	}
1513 }
1514 
1515 static void
1516 ampdu_tx_setup(struct ieee80211_tx_ampdu *tap)
1517 {
1518 	callout_init(&tap->txa_timer, CALLOUT_MPSAFE);
1519 	tap->txa_flags |= IEEE80211_AGGR_SETUP;
1520 }
1521 
1522 static void
1523 ampdu_tx_stop(struct ieee80211_tx_ampdu *tap)
1524 {
1525 	struct ieee80211_node *ni = tap->txa_ni;
1526 	struct ieee80211com *ic = ni->ni_ic;
1527 
1528 	KASSERT(tap->txa_flags & IEEE80211_AGGR_SETUP,
1529 	    ("txa_flags 0x%x ac %d", tap->txa_flags, tap->txa_ac));
1530 
1531 	/*
1532 	 * Stop BA stream if setup so driver has a chance
1533 	 * to reclaim any resources it might have allocated.
1534 	 */
1535 	ic->ic_addba_stop(ni, tap);
1536 	/*
1537 	 * Stop any pending BAR transmit.
1538 	 */
1539 	bar_stop_timer(tap);
1540 
1541 	tap->txa_lastsample = 0;
1542 	tap->txa_avgpps = 0;
1543 	/* NB: clearing NAK means we may re-send ADDBA */
1544 	tap->txa_flags &= ~(IEEE80211_AGGR_SETUP | IEEE80211_AGGR_NAK);
1545 }
1546 
1547 static void
1548 addba_timeout(void *arg)
1549 {
1550 	struct ieee80211_tx_ampdu *tap = arg;
1551 
1552 	/* XXX ? */
1553 	tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
1554 	tap->txa_attempts++;
1555 }
1556 
1557 static void
1558 addba_start_timeout(struct ieee80211_tx_ampdu *tap)
1559 {
1560 	/* XXX use CALLOUT_PENDING instead? */
1561 	callout_reset(&tap->txa_timer, ieee80211_addba_timeout,
1562 	    addba_timeout, tap);
1563 	tap->txa_flags |= IEEE80211_AGGR_XCHGPEND;
1564 	tap->txa_nextrequest = ticks + ieee80211_addba_timeout;
1565 }
1566 
1567 static void
1568 addba_stop_timeout(struct ieee80211_tx_ampdu *tap)
1569 {
1570 	/* XXX use CALLOUT_PENDING instead? */
1571 	if (tap->txa_flags & IEEE80211_AGGR_XCHGPEND) {
1572 		callout_stop(&tap->txa_timer);
1573 		tap->txa_flags &= ~IEEE80211_AGGR_XCHGPEND;
1574 	}
1575 }
1576 
1577 /*
1578  * Default method for requesting A-MPDU tx aggregation.
1579  * We setup the specified state block and start a timer
1580  * to wait for an ADDBA response frame.
1581  */
1582 static int
1583 ieee80211_addba_request(struct ieee80211_node *ni,
1584 	struct ieee80211_tx_ampdu *tap,
1585 	int dialogtoken, int baparamset, int batimeout)
1586 {
1587 	int bufsiz;
1588 
1589 	/* XXX locking */
1590 	tap->txa_token = dialogtoken;
1591 	tap->txa_flags |= IEEE80211_AGGR_IMMEDIATE;
1592 	bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1593 	tap->txa_wnd = (bufsiz == 0) ?
1594 	    IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
1595 	addba_start_timeout(tap);
1596 	return 1;
1597 }
1598 
1599 /*
1600  * Default method for processing an A-MPDU tx aggregation
1601  * response.  We shutdown any pending timer and update the
1602  * state block according to the reply.
1603  */
1604 static int
1605 ieee80211_addba_response(struct ieee80211_node *ni,
1606 	struct ieee80211_tx_ampdu *tap,
1607 	int status, int baparamset, int batimeout)
1608 {
1609 	int bufsiz, tid;
1610 
1611 	/* XXX locking */
1612 	addba_stop_timeout(tap);
1613 	if (status == IEEE80211_STATUS_SUCCESS) {
1614 		bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1615 		/* XXX override our request? */
1616 		tap->txa_wnd = (bufsiz == 0) ?
1617 		    IEEE80211_AGGR_BAWMAX : min(bufsiz, IEEE80211_AGGR_BAWMAX);
1618 		/* XXX AC/TID */
1619 		tid = MS(baparamset, IEEE80211_BAPS_TID);
1620 		tap->txa_flags |= IEEE80211_AGGR_RUNNING;
1621 		tap->txa_attempts = 0;
1622 	} else {
1623 		/* mark tid so we don't try again */
1624 		tap->txa_flags |= IEEE80211_AGGR_NAK;
1625 	}
1626 	return 1;
1627 }
1628 
1629 /*
1630  * Default method for stopping A-MPDU tx aggregation.
1631  * Any timer is cleared and we drain any pending frames.
1632  */
1633 static void
1634 ieee80211_addba_stop(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap)
1635 {
1636 	/* XXX locking */
1637 	addba_stop_timeout(tap);
1638 	if (tap->txa_flags & IEEE80211_AGGR_RUNNING) {
1639 		/* XXX clear aggregation queue */
1640 		tap->txa_flags &= ~IEEE80211_AGGR_RUNNING;
1641 	}
1642 	tap->txa_attempts = 0;
1643 }
1644 
1645 /*
1646  * Process a received action frame using the default aggregation
1647  * policy.  We intercept ADDBA-related frames and use them to
1648  * update our aggregation state.  All other frames are passed up
1649  * for processing by ieee80211_recv_action.
1650  */
1651 static int
1652 ht_recv_action_ba_addba_request(struct ieee80211_node *ni,
1653 	const struct ieee80211_frame *wh,
1654 	const uint8_t *frm, const uint8_t *efrm)
1655 {
1656 	struct ieee80211com *ic = ni->ni_ic;
1657 	struct ieee80211vap *vap = ni->ni_vap;
1658 	struct ieee80211_rx_ampdu *rap;
1659 	uint8_t dialogtoken;
1660 	uint16_t baparamset, batimeout, baseqctl;
1661 	uint16_t args[5];
1662 	int tid;
1663 
1664 	dialogtoken = frm[2];
1665 	baparamset = LE_READ_2(frm+3);
1666 	batimeout = LE_READ_2(frm+5);
1667 	baseqctl = LE_READ_2(frm+7);
1668 
1669 	tid = MS(baparamset, IEEE80211_BAPS_TID);
1670 
1671 	IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1672 	    "recv ADDBA request: dialogtoken %u baparamset 0x%x "
1673 	    "(tid %d bufsiz %d) batimeout %d baseqctl %d:%d",
1674 	    dialogtoken, baparamset,
1675 	    tid, MS(baparamset, IEEE80211_BAPS_BUFSIZ),
1676 	    batimeout,
1677 	    MS(baseqctl, IEEE80211_BASEQ_START),
1678 	    MS(baseqctl, IEEE80211_BASEQ_FRAG));
1679 
1680 	rap = &ni->ni_rx_ampdu[tid];
1681 
1682 	/* Send ADDBA response */
1683 	args[0] = dialogtoken;
1684 	/*
1685 	 * NB: We ack only if the sta associated with HT and
1686 	 * the ap is configured to do AMPDU rx (the latter
1687 	 * violates the 11n spec and is mostly for testing).
1688 	 */
1689 	if ((ni->ni_flags & IEEE80211_NODE_AMPDU_RX) &&
1690 	    (vap->iv_flags_ht & IEEE80211_FHT_AMPDU_RX)) {
1691 		/* XXX handle ampdu_rx_start failure */
1692 		ic->ic_ampdu_rx_start(ni, rap,
1693 		    baparamset, batimeout, baseqctl);
1694 
1695 		args[1] = IEEE80211_STATUS_SUCCESS;
1696 	} else {
1697 		IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1698 		    ni, "reject ADDBA request: %s",
1699 		    ni->ni_flags & IEEE80211_NODE_AMPDU_RX ?
1700 		       "administratively disabled" :
1701 		       "not negotiated for station");
1702 		vap->iv_stats.is_addba_reject++;
1703 		args[1] = IEEE80211_STATUS_UNSPECIFIED;
1704 	}
1705 	/* XXX honor rap flags? */
1706 	args[2] = IEEE80211_BAPS_POLICY_IMMEDIATE
1707 		| SM(tid, IEEE80211_BAPS_TID)
1708 		| SM(rap->rxa_wnd, IEEE80211_BAPS_BUFSIZ)
1709 		;
1710 	args[3] = 0;
1711 	args[4] = 0;
1712 	ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
1713 		IEEE80211_ACTION_BA_ADDBA_RESPONSE, args);
1714 	return 0;
1715 }
1716 
1717 static int
1718 ht_recv_action_ba_addba_response(struct ieee80211_node *ni,
1719 	const struct ieee80211_frame *wh,
1720 	const uint8_t *frm, const uint8_t *efrm)
1721 {
1722 	struct ieee80211com *ic = ni->ni_ic;
1723 	struct ieee80211vap *vap = ni->ni_vap;
1724 	struct ieee80211_tx_ampdu *tap;
1725 	uint8_t dialogtoken, policy;
1726 	uint16_t baparamset, batimeout, code;
1727 	int tid, ac, bufsiz;
1728 
1729 	dialogtoken = frm[2];
1730 	code = LE_READ_2(frm+3);
1731 	baparamset = LE_READ_2(frm+5);
1732 	tid = MS(baparamset, IEEE80211_BAPS_TID);
1733 	bufsiz = MS(baparamset, IEEE80211_BAPS_BUFSIZ);
1734 	policy = MS(baparamset, IEEE80211_BAPS_POLICY);
1735 	batimeout = LE_READ_2(frm+7);
1736 
1737 	ac = TID_TO_WME_AC(tid);
1738 	tap = &ni->ni_tx_ampdu[ac];
1739 	if ((tap->txa_flags & IEEE80211_AGGR_XCHGPEND) == 0) {
1740 		IEEE80211_DISCARD_MAC(vap,
1741 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1742 		    ni->ni_macaddr, "ADDBA response",
1743 		    "no pending ADDBA, tid %d dialogtoken %u "
1744 		    "code %d", tid, dialogtoken, code);
1745 		vap->iv_stats.is_addba_norequest++;
1746 		return 0;
1747 	}
1748 	if (dialogtoken != tap->txa_token) {
1749 		IEEE80211_DISCARD_MAC(vap,
1750 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1751 		    ni->ni_macaddr, "ADDBA response",
1752 		    "dialogtoken mismatch: waiting for %d, "
1753 		    "received %d, tid %d code %d",
1754 		    tap->txa_token, dialogtoken, tid, code);
1755 		vap->iv_stats.is_addba_badtoken++;
1756 		return 0;
1757 	}
1758 	/* NB: assumes IEEE80211_AGGR_IMMEDIATE is 1 */
1759 	if (policy != (tap->txa_flags & IEEE80211_AGGR_IMMEDIATE)) {
1760 		IEEE80211_DISCARD_MAC(vap,
1761 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1762 		    ni->ni_macaddr, "ADDBA response",
1763 		    "policy mismatch: expecting %s, "
1764 		    "received %s, tid %d code %d",
1765 		    tap->txa_flags & IEEE80211_AGGR_IMMEDIATE,
1766 		    policy, tid, code);
1767 		vap->iv_stats.is_addba_badpolicy++;
1768 		return 0;
1769 	}
1770 #if 0
1771 	/* XXX we take MIN in ieee80211_addba_response */
1772 	if (bufsiz > IEEE80211_AGGR_BAWMAX) {
1773 		IEEE80211_DISCARD_MAC(vap,
1774 		    IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1775 		    ni->ni_macaddr, "ADDBA response",
1776 		    "BA window too large: max %d, "
1777 		    "received %d, tid %d code %d",
1778 		    bufsiz, IEEE80211_AGGR_BAWMAX, tid, code);
1779 		vap->iv_stats.is_addba_badbawinsize++;
1780 		return 0;
1781 	}
1782 #endif
1783 	IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1784 	    "recv ADDBA response: dialogtoken %u code %d "
1785 	    "baparamset 0x%x (tid %d bufsiz %d) batimeout %d",
1786 	    dialogtoken, code, baparamset, tid, bufsiz,
1787 	    batimeout);
1788 	ic->ic_addba_response(ni, tap, code, baparamset, batimeout);
1789 	return 0;
1790 }
1791 
1792 static int
1793 ht_recv_action_ba_delba(struct ieee80211_node *ni,
1794 	const struct ieee80211_frame *wh,
1795 	const uint8_t *frm, const uint8_t *efrm)
1796 {
1797 	struct ieee80211com *ic = ni->ni_ic;
1798 	struct ieee80211_rx_ampdu *rap;
1799 	struct ieee80211_tx_ampdu *tap;
1800 	uint16_t baparamset, code;
1801 	int tid, ac;
1802 
1803 	baparamset = LE_READ_2(frm+2);
1804 	code = LE_READ_2(frm+4);
1805 
1806 	tid = MS(baparamset, IEEE80211_DELBAPS_TID);
1807 
1808 	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1809 	    "recv DELBA: baparamset 0x%x (tid %d initiator %d) "
1810 	    "code %d", baparamset, tid,
1811 	    MS(baparamset, IEEE80211_DELBAPS_INIT), code);
1812 
1813 	if ((baparamset & IEEE80211_DELBAPS_INIT) == 0) {
1814 		ac = TID_TO_WME_AC(tid);
1815 		tap = &ni->ni_tx_ampdu[ac];
1816 		ic->ic_addba_stop(ni, tap);
1817 	} else {
1818 		rap = &ni->ni_rx_ampdu[tid];
1819 		ic->ic_ampdu_rx_stop(ni, rap);
1820 	}
1821 	return 0;
1822 }
1823 
1824 static int
1825 ht_recv_action_ht_txchwidth(struct ieee80211_node *ni,
1826 	const struct ieee80211_frame *wh,
1827 	const uint8_t *frm, const uint8_t *efrm)
1828 {
1829 	int chw;
1830 
1831 	chw = (frm[2] == IEEE80211_A_HT_TXCHWIDTH_2040) ? 40 : 20;
1832 
1833 	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1834 	    "%s: HT txchwidth, width %d%s",
1835 	    __func__, chw, ni->ni_chw != chw ? "*" : "");
1836 	if (chw != ni->ni_chw) {
1837 		ni->ni_chw = chw;
1838 		/* XXX notify on change */
1839 	}
1840 	return 0;
1841 }
1842 
1843 static int
1844 ht_recv_action_ht_mimopwrsave(struct ieee80211_node *ni,
1845 	const struct ieee80211_frame *wh,
1846 	const uint8_t *frm, const uint8_t *efrm)
1847 {
1848 	const struct ieee80211_action_ht_mimopowersave *mps =
1849 	    (const struct ieee80211_action_ht_mimopowersave *) frm;
1850 
1851 	/* XXX check iv_htcaps */
1852 	if (mps->am_control & IEEE80211_A_HT_MIMOPWRSAVE_ENA)
1853 		ni->ni_flags |= IEEE80211_NODE_MIMO_PS;
1854 	else
1855 		ni->ni_flags &= ~IEEE80211_NODE_MIMO_PS;
1856 	if (mps->am_control & IEEE80211_A_HT_MIMOPWRSAVE_MODE)
1857 		ni->ni_flags |= IEEE80211_NODE_MIMO_RTS;
1858 	else
1859 		ni->ni_flags &= ~IEEE80211_NODE_MIMO_RTS;
1860 	/* XXX notify on change */
1861 	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
1862 	    "%s: HT MIMO PS (%s%s)", __func__,
1863 	    (ni->ni_flags & IEEE80211_NODE_MIMO_PS) ?  "on" : "off",
1864 	    (ni->ni_flags & IEEE80211_NODE_MIMO_RTS) ?  "+rts" : ""
1865 	);
1866 	return 0;
1867 }
1868 
1869 /*
1870  * Transmit processing.
1871  */
1872 
1873 /*
1874  * Check if A-MPDU should be requested/enabled for a stream.
1875  * We require a traffic rate above a per-AC threshold and we
1876  * also handle backoff from previous failed attempts.
1877  *
1878  * Drivers may override this method to bring in information
1879  * such as link state conditions in making the decision.
1880  */
1881 static int
1882 ieee80211_ampdu_enable(struct ieee80211_node *ni,
1883 	struct ieee80211_tx_ampdu *tap)
1884 {
1885 	struct ieee80211vap *vap = ni->ni_vap;
1886 
1887 	if (tap->txa_avgpps < vap->iv_ampdu_mintraffic[tap->txa_ac])
1888 		return 0;
1889 	/* XXX check rssi? */
1890 	if (tap->txa_attempts >= ieee80211_addba_maxtries &&
1891 	    ticks < tap->txa_nextrequest) {
1892 		/*
1893 		 * Don't retry too often; txa_nextrequest is set
1894 		 * to the minimum interval we'll retry after
1895 		 * ieee80211_addba_maxtries failed attempts are made.
1896 		 */
1897 		return 0;
1898 	}
1899 	IEEE80211_NOTE(vap, IEEE80211_MSG_11N, ni,
1900 	    "enable AMPDU on %s, avgpps %d pkts %d",
1901 	    ieee80211_wme_acnames[tap->txa_ac], tap->txa_avgpps, tap->txa_pkts);
1902 	return 1;
1903 }
1904 
1905 /*
1906  * Request A-MPDU tx aggregation.  Setup local state and
1907  * issue an ADDBA request.  BA use will only happen after
1908  * the other end replies with ADDBA response.
1909  */
1910 int
1911 ieee80211_ampdu_request(struct ieee80211_node *ni,
1912 	struct ieee80211_tx_ampdu *tap)
1913 {
1914 	struct ieee80211com *ic = ni->ni_ic;
1915 	uint16_t args[5];
1916 	int tid, dialogtoken;
1917 	static int tokens = 0;	/* XXX */
1918 
1919 	/* XXX locking */
1920 	if ((tap->txa_flags & IEEE80211_AGGR_SETUP) == 0) {
1921 		/* do deferred setup of state */
1922 		ampdu_tx_setup(tap);
1923 	}
1924 	/* XXX hack for not doing proper locking */
1925 	tap->txa_flags &= ~IEEE80211_AGGR_NAK;
1926 
1927 	dialogtoken = (tokens+1) % 63;		/* XXX */
1928 	tid = WME_AC_TO_TID(tap->txa_ac);
1929 	tap->txa_start = ni->ni_txseqs[tid];
1930 
1931 	args[0] = dialogtoken;
1932 	args[1] = 0;	/* NB: status code not used */
1933 	args[2]	= IEEE80211_BAPS_POLICY_IMMEDIATE
1934 		| SM(tid, IEEE80211_BAPS_TID)
1935 		| SM(IEEE80211_AGGR_BAWMAX, IEEE80211_BAPS_BUFSIZ)
1936 		;
1937 	args[3] = 0;	/* batimeout */
1938 	/* NB: do first so there's no race against reply */
1939 	if (!ic->ic_addba_request(ni, tap, dialogtoken, args[2], args[3])) {
1940 		/* unable to setup state, don't make request */
1941 		IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_11N,
1942 		    ni, "%s: could not setup BA stream for AC %d",
1943 		    __func__, tap->txa_ac);
1944 		/* defer next try so we don't slam the driver with requests */
1945 		tap->txa_attempts = ieee80211_addba_maxtries;
1946 		/* NB: check in case driver wants to override */
1947 		if (tap->txa_nextrequest <= ticks)
1948 			tap->txa_nextrequest = ticks + ieee80211_addba_backoff;
1949 		return 0;
1950 	}
1951 	tokens = dialogtoken;			/* allocate token */
1952 	/* NB: after calling ic_addba_request so driver can set txa_start */
1953 	args[4] = SM(tap->txa_start, IEEE80211_BASEQ_START)
1954 		| SM(0, IEEE80211_BASEQ_FRAG)
1955 		;
1956 	return ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
1957 		IEEE80211_ACTION_BA_ADDBA_REQUEST, args);
1958 }
1959 
1960 /*
1961  * Terminate an AMPDU tx stream.  State is reclaimed
1962  * and the peer notified with a DelBA Action frame.
1963  */
1964 void
1965 ieee80211_ampdu_stop(struct ieee80211_node *ni, struct ieee80211_tx_ampdu *tap,
1966 	int reason)
1967 {
1968 	struct ieee80211com *ic = ni->ni_ic;
1969 	struct ieee80211vap *vap = ni->ni_vap;
1970 	uint16_t args[4];
1971 
1972 	/* XXX locking */
1973 	tap->txa_flags &= ~IEEE80211_AGGR_BARPEND;
1974 	if (IEEE80211_AMPDU_RUNNING(tap)) {
1975 		IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1976 		    ni, "%s: stop BA stream for AC %d (reason %d)",
1977 		    __func__, tap->txa_ac, reason);
1978 		vap->iv_stats.is_ampdu_stop++;
1979 
1980 		ic->ic_addba_stop(ni, tap);
1981 		args[0] = WME_AC_TO_TID(tap->txa_ac);
1982 		args[1] = IEEE80211_DELBAPS_INIT;
1983 		args[2] = reason;			/* XXX reason code */
1984 		ic->ic_send_action(ni, IEEE80211_ACTION_CAT_BA,
1985 			IEEE80211_ACTION_BA_DELBA, args);
1986 	} else {
1987 		IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N,
1988 		    ni, "%s: BA stream for AC %d not running (reason %d)",
1989 		    __func__, tap->txa_ac, reason);
1990 		vap->iv_stats.is_ampdu_stop_failed++;
1991 	}
1992 }
1993 
1994 static void
1995 bar_timeout(void *arg)
1996 {
1997 	struct ieee80211_tx_ampdu *tap = arg;
1998 	struct ieee80211_node *ni = tap->txa_ni;
1999 
2000 	KASSERT((tap->txa_flags & IEEE80211_AGGR_XCHGPEND) == 0,
2001 	    ("bar/addba collision, flags 0x%x", tap->txa_flags));
2002 
2003 	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_11N,
2004 	    ni, "%s: tid %u flags 0x%x attempts %d", __func__,
2005 	    tap->txa_ac, tap->txa_flags, tap->txa_attempts);
2006 
2007 	/* guard against race with bar_tx_complete */
2008 	if ((tap->txa_flags & IEEE80211_AGGR_BARPEND) == 0)
2009 		return;
2010 	/* XXX ? */
2011 	if (tap->txa_attempts >= ieee80211_bar_maxtries)
2012 		ieee80211_ampdu_stop(ni, tap, IEEE80211_REASON_TIMEOUT);
2013 	else
2014 		ieee80211_send_bar(ni, tap, tap->txa_seqpending);
2015 }
2016 
2017 static void
2018 bar_start_timer(struct ieee80211_tx_ampdu *tap)
2019 {
2020 	callout_reset(&tap->txa_timer, ieee80211_bar_timeout, bar_timeout, tap);
2021 }
2022 
2023 static void
2024 bar_stop_timer(struct ieee80211_tx_ampdu *tap)
2025 {
2026 	callout_stop(&tap->txa_timer);
2027 }
2028 
2029 static void
2030 bar_tx_complete(struct ieee80211_node *ni, void *arg, int status)
2031 {
2032 	struct ieee80211_tx_ampdu *tap = arg;
2033 
2034 	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_11N,
2035 	    ni, "%s: tid %u flags 0x%x pending %d status %d",
2036 	    __func__, tap->txa_ac, tap->txa_flags,
2037 	    callout_pending(&tap->txa_timer), status);
2038 
2039 	/* XXX locking */
2040 	if ((tap->txa_flags & IEEE80211_AGGR_BARPEND) &&
2041 	    callout_pending(&tap->txa_timer)) {
2042 		struct ieee80211com *ic = ni->ni_ic;
2043 
2044 		if (status)		/* ACK'd */
2045 			bar_stop_timer(tap);
2046 		ic->ic_bar_response(ni, tap, status);
2047 		/* NB: just let timer expire so we pace requests */
2048 	}
2049 }
2050 
2051 static void
2052 ieee80211_bar_response(struct ieee80211_node *ni,
2053 	struct ieee80211_tx_ampdu *tap, int status)
2054 {
2055 
2056 	if (status != 0) {		/* got ACK */
2057 		IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_11N,
2058 		    ni, "BAR moves BA win <%u:%u> (%u frames) txseq %u tid %u",
2059 		    tap->txa_start,
2060 		    IEEE80211_SEQ_ADD(tap->txa_start, tap->txa_wnd-1),
2061 		    tap->txa_qframes, tap->txa_seqpending,
2062 		    WME_AC_TO_TID(tap->txa_ac));
2063 
2064 		/* NB: timer already stopped in bar_tx_complete */
2065 		tap->txa_start = tap->txa_seqpending;
2066 		tap->txa_flags &= ~IEEE80211_AGGR_BARPEND;
2067 	}
2068 }
2069 
2070 /*
2071  * Transmit a BAR frame to the specified node.  The
2072  * BAR contents are drawn from the supplied aggregation
2073  * state associated with the node.
2074  *
2075  * NB: we only handle immediate ACK w/ compressed bitmap.
2076  */
2077 int
2078 ieee80211_send_bar(struct ieee80211_node *ni,
2079 	struct ieee80211_tx_ampdu *tap, ieee80211_seq seq)
2080 {
2081 #define	senderr(_x, _v)	do { vap->iv_stats._v++; ret = _x; goto bad; } while (0)
2082 	struct ieee80211vap *vap = ni->ni_vap;
2083 	struct ieee80211com *ic = ni->ni_ic;
2084 	struct ieee80211_frame_bar *bar;
2085 	struct mbuf *m;
2086 	uint16_t barctl, barseqctl;
2087 	uint8_t *frm;
2088 	int tid, ret;
2089 
2090 	if ((tap->txa_flags & IEEE80211_AGGR_RUNNING) == 0) {
2091 		/* no ADDBA response, should not happen */
2092 		/* XXX stat+msg */
2093 		return EINVAL;
2094 	}
2095 	/* XXX locking */
2096 	bar_stop_timer(tap);
2097 
2098 	ieee80211_ref_node(ni);
2099 
2100 	m = ieee80211_getmgtframe(&frm, ic->ic_headroom, sizeof(*bar));
2101 	if (m == NULL)
2102 		senderr(ENOMEM, is_tx_nobuf);
2103 
2104 	if (!ieee80211_add_callback(m, bar_tx_complete, tap)) {
2105 		m_freem(m);
2106 		senderr(ENOMEM, is_tx_nobuf);	/* XXX */
2107 		/* NOTREACHED */
2108 	}
2109 
2110 	bar = mtod(m, struct ieee80211_frame_bar *);
2111 	bar->i_fc[0] = IEEE80211_FC0_VERSION_0 |
2112 		IEEE80211_FC0_TYPE_CTL | IEEE80211_FC0_SUBTYPE_BAR;
2113 	bar->i_fc[1] = 0;
2114 	IEEE80211_ADDR_COPY(bar->i_ra, ni->ni_macaddr);
2115 	IEEE80211_ADDR_COPY(bar->i_ta, vap->iv_myaddr);
2116 
2117 	tid = WME_AC_TO_TID(tap->txa_ac);
2118 	barctl 	= (tap->txa_flags & IEEE80211_AGGR_IMMEDIATE ?
2119 			0 : IEEE80211_BAR_NOACK)
2120 		| IEEE80211_BAR_COMP
2121 		| SM(tid, IEEE80211_BAR_TID)
2122 		;
2123 	barseqctl = SM(seq, IEEE80211_BAR_SEQ_START);
2124 	/* NB: known to have proper alignment */
2125 	bar->i_ctl = htole16(barctl);
2126 	bar->i_seq = htole16(barseqctl);
2127 	m->m_pkthdr.len = m->m_len = sizeof(struct ieee80211_frame_bar);
2128 
2129 	M_WME_SETAC(m, WME_AC_VO);
2130 
2131 	IEEE80211_NODE_STAT(ni, tx_mgmt);	/* XXX tx_ctl? */
2132 
2133 	/* XXX locking */
2134 	/* init/bump attempts counter */
2135 	if ((tap->txa_flags & IEEE80211_AGGR_BARPEND) == 0)
2136 		tap->txa_attempts = 1;
2137 	else
2138 		tap->txa_attempts++;
2139 	tap->txa_seqpending = seq;
2140 	tap->txa_flags |= IEEE80211_AGGR_BARPEND;
2141 
2142 	IEEE80211_NOTE(vap, IEEE80211_MSG_DEBUG | IEEE80211_MSG_11N,
2143 	    ni, "send BAR: tid %u ctl 0x%x start %u (attempt %d)",
2144 	    tid, barctl, seq, tap->txa_attempts);
2145 
2146 	ret = ic->ic_raw_xmit(ni, m, NULL);
2147 	if (ret != 0) {
2148 		/* xmit failed, clear state flag */
2149 		tap->txa_flags &= ~IEEE80211_AGGR_BARPEND;
2150 		goto bad;
2151 	}
2152 	/* XXX hack against tx complete happening before timer is started */
2153 	if (tap->txa_flags & IEEE80211_AGGR_BARPEND)
2154 		bar_start_timer(tap);
2155 	return 0;
2156 bad:
2157 	ieee80211_free_node(ni);
2158 	return ret;
2159 #undef senderr
2160 }
2161 
2162 static int
2163 ht_action_output(struct ieee80211_node *ni, struct mbuf *m)
2164 {
2165 	struct ieee80211_bpf_params params;
2166 
2167 	memset(&params, 0, sizeof(params));
2168 	params.ibp_pri = WME_AC_VO;
2169 	params.ibp_rate0 = ni->ni_txparms->mgmtrate;
2170 	/* NB: we know all frames are unicast */
2171 	params.ibp_try0 = ni->ni_txparms->maxretry;
2172 	params.ibp_power = ni->ni_txpower;
2173 	return ieee80211_mgmt_output(ni, m, IEEE80211_FC0_SUBTYPE_ACTION,
2174 	     &params);
2175 }
2176 
2177 #define	ADDSHORT(frm, v) do {			\
2178 	frm[0] = (v) & 0xff;			\
2179 	frm[1] = (v) >> 8;			\
2180 	frm += 2;				\
2181 } while (0)
2182 
2183 /*
2184  * Send an action management frame.  The arguments are stuff
2185  * into a frame without inspection; the caller is assumed to
2186  * prepare them carefully (e.g. based on the aggregation state).
2187  */
2188 static int
2189 ht_send_action_ba_addba(struct ieee80211_node *ni,
2190 	int category, int action, void *arg0)
2191 {
2192 	struct ieee80211vap *vap = ni->ni_vap;
2193 	struct ieee80211com *ic = ni->ni_ic;
2194 	uint16_t *args = arg0;
2195 	struct mbuf *m;
2196 	uint8_t *frm;
2197 
2198 	IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
2199 	    "send ADDBA %s: dialogtoken %d status %d "
2200 	    "baparamset 0x%x (tid %d) batimeout 0x%x baseqctl 0x%x",
2201 	    (action == IEEE80211_ACTION_BA_ADDBA_REQUEST) ?
2202 		"request" : "response",
2203 	    args[0], args[1], args[2], MS(args[2], IEEE80211_BAPS_TID),
2204 	    args[3], args[4]);
2205 
2206 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
2207 	    "ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n", __func__, __LINE__,
2208 	    ni, ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni)+1);
2209 	ieee80211_ref_node(ni);
2210 
2211 	m = ieee80211_getmgtframe(&frm,
2212 	    ic->ic_headroom + sizeof(struct ieee80211_frame),
2213 	    sizeof(uint16_t)	/* action+category */
2214 	    /* XXX may action payload */
2215 	    + sizeof(struct ieee80211_action_ba_addbaresponse)
2216 	);
2217 	if (m != NULL) {
2218 		*frm++ = category;
2219 		*frm++ = action;
2220 		*frm++ = args[0];		/* dialog token */
2221 		if (action == IEEE80211_ACTION_BA_ADDBA_RESPONSE)
2222 			ADDSHORT(frm, args[1]);	/* status code */
2223 		ADDSHORT(frm, args[2]);		/* baparamset */
2224 		ADDSHORT(frm, args[3]);		/* batimeout */
2225 		if (action == IEEE80211_ACTION_BA_ADDBA_REQUEST)
2226 			ADDSHORT(frm, args[4]);	/* baseqctl */
2227 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
2228 		return ht_action_output(ni, m);
2229 	} else {
2230 		vap->iv_stats.is_tx_nobuf++;
2231 		ieee80211_free_node(ni);
2232 		return ENOMEM;
2233 	}
2234 }
2235 
2236 static int
2237 ht_send_action_ba_delba(struct ieee80211_node *ni,
2238 	int category, int action, void *arg0)
2239 {
2240 	struct ieee80211vap *vap = ni->ni_vap;
2241 	struct ieee80211com *ic = ni->ni_ic;
2242 	uint16_t *args = arg0;
2243 	struct mbuf *m;
2244 	uint16_t baparamset;
2245 	uint8_t *frm;
2246 
2247 	baparamset = SM(args[0], IEEE80211_DELBAPS_TID)
2248 		   | args[1]
2249 		   ;
2250 	IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
2251 	    "send DELBA action: tid %d, initiator %d reason %d",
2252 	    args[0], args[1], args[2]);
2253 
2254 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
2255 	    "ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n", __func__, __LINE__,
2256 	    ni, ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni)+1);
2257 	ieee80211_ref_node(ni);
2258 
2259 	m = ieee80211_getmgtframe(&frm,
2260 	    ic->ic_headroom + sizeof(struct ieee80211_frame),
2261 	    sizeof(uint16_t)	/* action+category */
2262 	    /* XXX may action payload */
2263 	    + sizeof(struct ieee80211_action_ba_addbaresponse)
2264 	);
2265 	if (m != NULL) {
2266 		*frm++ = category;
2267 		*frm++ = action;
2268 		ADDSHORT(frm, baparamset);
2269 		ADDSHORT(frm, args[2]);		/* reason code */
2270 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
2271 		return ht_action_output(ni, m);
2272 	} else {
2273 		vap->iv_stats.is_tx_nobuf++;
2274 		ieee80211_free_node(ni);
2275 		return ENOMEM;
2276 	}
2277 }
2278 
2279 static int
2280 ht_send_action_ht_txchwidth(struct ieee80211_node *ni,
2281 	int category, int action, void *arg0)
2282 {
2283 	struct ieee80211vap *vap = ni->ni_vap;
2284 	struct ieee80211com *ic = ni->ni_ic;
2285 	struct mbuf *m;
2286 	uint8_t *frm;
2287 
2288 	IEEE80211_NOTE(vap, IEEE80211_MSG_ACTION | IEEE80211_MSG_11N, ni,
2289 	    "send HT txchwidth: width %d",
2290 	    IEEE80211_IS_CHAN_HT40(ni->ni_chan) ? 40 : 20);
2291 
2292 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
2293 	    "ieee80211_ref_node (%s:%u) %p<%s> refcnt %d\n", __func__, __LINE__,
2294 	    ni, ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni)+1);
2295 	ieee80211_ref_node(ni);
2296 
2297 	m = ieee80211_getmgtframe(&frm,
2298 	    ic->ic_headroom + sizeof(struct ieee80211_frame),
2299 	    sizeof(uint16_t)	/* action+category */
2300 	    /* XXX may action payload */
2301 	    + sizeof(struct ieee80211_action_ba_addbaresponse)
2302 	);
2303 	if (m != NULL) {
2304 		*frm++ = category;
2305 		*frm++ = action;
2306 		*frm++ = IEEE80211_IS_CHAN_HT40(ni->ni_chan) ?
2307 			IEEE80211_A_HT_TXCHWIDTH_2040 :
2308 			IEEE80211_A_HT_TXCHWIDTH_20;
2309 		m->m_pkthdr.len = m->m_len = frm - mtod(m, uint8_t *);
2310 		return ht_action_output(ni, m);
2311 	} else {
2312 		vap->iv_stats.is_tx_nobuf++;
2313 		ieee80211_free_node(ni);
2314 		return ENOMEM;
2315 	}
2316 }
2317 #undef ADDSHORT
2318 
2319 /*
2320  * Construct the MCS bit mask for inclusion
2321  * in an HT information element.
2322  */
2323 static void
2324 ieee80211_set_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
2325 {
2326 	int i;
2327 
2328 	for (i = 0; i < rs->rs_nrates; i++) {
2329 		int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
2330 		if (r < IEEE80211_HTRATE_MAXSIZE) {	/* XXX? */
2331 			/* NB: this assumes a particular implementation */
2332 			setbit(frm, r);
2333 		}
2334 	}
2335 }
2336 
2337 /*
2338  * Add body of an HTCAP information element.
2339  */
2340 static uint8_t *
2341 ieee80211_add_htcap_body(uint8_t *frm, struct ieee80211_node *ni)
2342 {
2343 #define	ADDSHORT(frm, v) do {			\
2344 	frm[0] = (v) & 0xff;			\
2345 	frm[1] = (v) >> 8;			\
2346 	frm += 2;				\
2347 } while (0)
2348 	struct ieee80211vap *vap = ni->ni_vap;
2349 	uint16_t caps, extcaps;
2350 	int rxmax, density;
2351 
2352 	/* HT capabilities */
2353 	caps = vap->iv_htcaps & 0xffff;
2354 	/*
2355 	 * Note channel width depends on whether we are operating as
2356 	 * a sta or not.  When operating as a sta we are generating
2357 	 * a request based on our desired configuration.  Otherwise
2358 	 * we are operational and the channel attributes identify
2359 	 * how we've been setup (which might be different if a fixed
2360 	 * channel is specified).
2361 	 */
2362 	if (vap->iv_opmode == IEEE80211_M_STA) {
2363 		/* override 20/40 use based on config */
2364 		if (vap->iv_flags_ht & IEEE80211_FHT_USEHT40)
2365 			caps |= IEEE80211_HTCAP_CHWIDTH40;
2366 		else
2367 			caps &= ~IEEE80211_HTCAP_CHWIDTH40;
2368 		/* use advertised setting (XXX locally constraint) */
2369 		rxmax = MS(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU);
2370 		density = MS(ni->ni_htparam, IEEE80211_HTCAP_MPDUDENSITY);
2371 	} else {
2372 		/* override 20/40 use based on current channel */
2373 		if (IEEE80211_IS_CHAN_HT40(ni->ni_chan))
2374 			caps |= IEEE80211_HTCAP_CHWIDTH40;
2375 		else
2376 			caps &= ~IEEE80211_HTCAP_CHWIDTH40;
2377 		rxmax = vap->iv_ampdu_rxmax;
2378 		density = vap->iv_ampdu_density;
2379 	}
2380 	/* adjust short GI based on channel and config */
2381 	if ((vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20) == 0)
2382 		caps &= ~IEEE80211_HTCAP_SHORTGI20;
2383 	if ((vap->iv_flags_ht & IEEE80211_FHT_SHORTGI40) == 0 ||
2384 	    (caps & IEEE80211_HTCAP_CHWIDTH40) == 0)
2385 		caps &= ~IEEE80211_HTCAP_SHORTGI40;
2386 	ADDSHORT(frm, caps);
2387 
2388 	/* HT parameters */
2389 	*frm = SM(rxmax, IEEE80211_HTCAP_MAXRXAMPDU)
2390 	     | SM(density, IEEE80211_HTCAP_MPDUDENSITY)
2391 	     ;
2392 	frm++;
2393 
2394 	/* pre-zero remainder of ie */
2395 	memset(frm, 0, sizeof(struct ieee80211_ie_htcap) -
2396 		__offsetof(struct ieee80211_ie_htcap, hc_mcsset));
2397 
2398 	/* supported MCS set */
2399 	/*
2400 	 * XXX it would better to get the rate set from ni_htrates
2401 	 * so we can restrict it but for sta mode ni_htrates isn't
2402 	 * setup when we're called to form an AssocReq frame so for
2403 	 * now we're restricted to the default HT rate set.
2404 	 */
2405 	ieee80211_set_htrates(frm, &ieee80211_rateset_11n);
2406 
2407 	frm += __offsetof(struct ieee80211_ie_htcap, hc_extcap) -
2408 		__offsetof(struct ieee80211_ie_htcap, hc_mcsset);
2409 
2410 	/* HT extended capabilities */
2411 	extcaps = vap->iv_htextcaps & 0xffff;
2412 
2413 	ADDSHORT(frm, extcaps);
2414 
2415 	frm += sizeof(struct ieee80211_ie_htcap) -
2416 		__offsetof(struct ieee80211_ie_htcap, hc_txbf);
2417 
2418 	return frm;
2419 #undef ADDSHORT
2420 }
2421 
2422 /*
2423  * Add 802.11n HT capabilities information element
2424  */
2425 uint8_t *
2426 ieee80211_add_htcap(uint8_t *frm, struct ieee80211_node *ni)
2427 {
2428 	frm[0] = IEEE80211_ELEMID_HTCAP;
2429 	frm[1] = sizeof(struct ieee80211_ie_htcap) - 2;
2430 	return ieee80211_add_htcap_body(frm + 2, ni);
2431 }
2432 
2433 /*
2434  * Add Broadcom OUI wrapped standard HTCAP ie; this is
2435  * used for compatibility w/ pre-draft implementations.
2436  */
2437 uint8_t *
2438 ieee80211_add_htcap_vendor(uint8_t *frm, struct ieee80211_node *ni)
2439 {
2440 	frm[0] = IEEE80211_ELEMID_VENDOR;
2441 	frm[1] = 4 + sizeof(struct ieee80211_ie_htcap) - 2;
2442 	frm[2] = (BCM_OUI >> 0) & 0xff;
2443 	frm[3] = (BCM_OUI >> 8) & 0xff;
2444 	frm[4] = (BCM_OUI >> 16) & 0xff;
2445 	frm[5] = BCM_OUI_HTCAP;
2446 	return ieee80211_add_htcap_body(frm + 6, ni);
2447 }
2448 
2449 /*
2450  * Construct the MCS bit mask of basic rates
2451  * for inclusion in an HT information element.
2452  */
2453 static void
2454 ieee80211_set_basic_htrates(uint8_t *frm, const struct ieee80211_htrateset *rs)
2455 {
2456 	int i;
2457 
2458 	for (i = 0; i < rs->rs_nrates; i++) {
2459 		int r = rs->rs_rates[i] & IEEE80211_RATE_VAL;
2460 		if ((rs->rs_rates[i] & IEEE80211_RATE_BASIC) &&
2461 		    r < IEEE80211_HTRATE_MAXSIZE) {
2462 			/* NB: this assumes a particular implementation */
2463 			setbit(frm, r);
2464 		}
2465 	}
2466 }
2467 
2468 /*
2469  * Update the HTINFO ie for a beacon frame.
2470  */
2471 void
2472 ieee80211_ht_update_beacon(struct ieee80211vap *vap,
2473 	struct ieee80211_beacon_offsets *bo)
2474 {
2475 #define	PROTMODE	(IEEE80211_HTINFO_OPMODE|IEEE80211_HTINFO_NONHT_PRESENT)
2476 	const struct ieee80211_channel *bsschan = vap->iv_bss->ni_chan;
2477 	struct ieee80211com *ic = vap->iv_ic;
2478 	struct ieee80211_ie_htinfo *ht =
2479 	   (struct ieee80211_ie_htinfo *) bo->bo_htinfo;
2480 
2481 	/* XXX only update on channel change */
2482 	ht->hi_ctrlchannel = ieee80211_chan2ieee(ic, bsschan);
2483 	if (vap->iv_flags_ht & IEEE80211_FHT_RIFS)
2484 		ht->hi_byte1 = IEEE80211_HTINFO_RIFSMODE_PERM;
2485 	else
2486 		ht->hi_byte1 = IEEE80211_HTINFO_RIFSMODE_PROH;
2487 	if (IEEE80211_IS_CHAN_HT40U(bsschan))
2488 		ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
2489 	else if (IEEE80211_IS_CHAN_HT40D(bsschan))
2490 		ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_BELOW;
2491 	else
2492 		ht->hi_byte1 |= IEEE80211_HTINFO_2NDCHAN_NONE;
2493 	if (IEEE80211_IS_CHAN_HT40(bsschan))
2494 		ht->hi_byte1 |= IEEE80211_HTINFO_TXWIDTH_2040;
2495 
2496 	/* protection mode */
2497 	ht->hi_byte2 = (ht->hi_byte2 &~ PROTMODE) | ic->ic_curhtprotmode;
2498 
2499 	/* XXX propagate to vendor ie's */
2500 #undef PROTMODE
2501 }
2502 
2503 /*
2504  * Add body of an HTINFO information element.
2505  *
2506  * NB: We don't use struct ieee80211_ie_htinfo because we can
2507  * be called to fillin both a standard ie and a compat ie that
2508  * has a vendor OUI at the front.
2509  */
2510 static uint8_t *
2511 ieee80211_add_htinfo_body(uint8_t *frm, struct ieee80211_node *ni)
2512 {
2513 	struct ieee80211vap *vap = ni->ni_vap;
2514 	struct ieee80211com *ic = ni->ni_ic;
2515 
2516 	/* pre-zero remainder of ie */
2517 	memset(frm, 0, sizeof(struct ieee80211_ie_htinfo) - 2);
2518 
2519 	/* primary/control channel center */
2520 	*frm++ = ieee80211_chan2ieee(ic, ni->ni_chan);
2521 
2522 	if (vap->iv_flags_ht & IEEE80211_FHT_RIFS)
2523 		frm[0] = IEEE80211_HTINFO_RIFSMODE_PERM;
2524 	else
2525 		frm[0] = IEEE80211_HTINFO_RIFSMODE_PROH;
2526 	if (IEEE80211_IS_CHAN_HT40U(ni->ni_chan))
2527 		frm[0] |= IEEE80211_HTINFO_2NDCHAN_ABOVE;
2528 	else if (IEEE80211_IS_CHAN_HT40D(ni->ni_chan))
2529 		frm[0] |= IEEE80211_HTINFO_2NDCHAN_BELOW;
2530 	else
2531 		frm[0] |= IEEE80211_HTINFO_2NDCHAN_NONE;
2532 	if (IEEE80211_IS_CHAN_HT40(ni->ni_chan))
2533 		frm[0] |= IEEE80211_HTINFO_TXWIDTH_2040;
2534 
2535 	frm[1] = ic->ic_curhtprotmode;
2536 
2537 	frm += 5;
2538 
2539 	/* basic MCS set */
2540 	ieee80211_set_basic_htrates(frm, &ni->ni_htrates);
2541 	frm += sizeof(struct ieee80211_ie_htinfo) -
2542 		__offsetof(struct ieee80211_ie_htinfo, hi_basicmcsset);
2543 	return frm;
2544 }
2545 
2546 /*
2547  * Add 802.11n HT information information element.
2548  */
2549 uint8_t *
2550 ieee80211_add_htinfo(uint8_t *frm, struct ieee80211_node *ni)
2551 {
2552 	frm[0] = IEEE80211_ELEMID_HTINFO;
2553 	frm[1] = sizeof(struct ieee80211_ie_htinfo) - 2;
2554 	return ieee80211_add_htinfo_body(frm + 2, ni);
2555 }
2556 
2557 /*
2558  * Add Broadcom OUI wrapped standard HTINFO ie; this is
2559  * used for compatibility w/ pre-draft implementations.
2560  */
2561 uint8_t *
2562 ieee80211_add_htinfo_vendor(uint8_t *frm, struct ieee80211_node *ni)
2563 {
2564 	frm[0] = IEEE80211_ELEMID_VENDOR;
2565 	frm[1] = 4 + sizeof(struct ieee80211_ie_htinfo) - 2;
2566 	frm[2] = (BCM_OUI >> 0) & 0xff;
2567 	frm[3] = (BCM_OUI >> 8) & 0xff;
2568 	frm[4] = (BCM_OUI >> 16) & 0xff;
2569 	frm[5] = BCM_OUI_HTINFO;
2570 	return ieee80211_add_htinfo_body(frm + 6, ni);
2571 }
2572