xref: /openbsd-src/sys/net80211/ieee80211.c (revision 99fd087599a8791921855f21bd7e36130f39aadc)
1 /*	$OpenBSD: ieee80211.c,v 1.82 2019/12/27 09:46:13 stsp Exp $	*/
2 /*	$NetBSD: ieee80211.c,v 1.19 2004/06/06 05:45:29 dyoung Exp $	*/
3 
4 /*-
5  * Copyright (c) 2001 Atsushi Onoe
6  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * IEEE 802.11 generic handler
34  */
35 
36 #include "bpfilter.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/mbuf.h>
41 #include <sys/kernel.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/endian.h>
45 #include <sys/errno.h>
46 #include <sys/sysctl.h>
47 
48 #include <net/if.h>
49 #include <net/if_dl.h>
50 #include <net/if_media.h>
51 
52 #if NBPFILTER > 0
53 #include <net/bpf.h>
54 #endif
55 
56 #include <netinet/in.h>
57 #include <netinet/if_ether.h>
58 
59 #include <net80211/ieee80211_var.h>
60 #include <net80211/ieee80211_priv.h>
61 
62 #ifdef IEEE80211_DEBUG
63 int	ieee80211_debug = 0;
64 #endif
65 
66 int ieee80211_cache_size = IEEE80211_CACHE_SIZE;
67 
68 void ieee80211_setbasicrates(struct ieee80211com *);
69 int ieee80211_findrate(struct ieee80211com *, enum ieee80211_phymode, int);
70 void ieee80211_configure_ampdu_tx(struct ieee80211com *, int);
71 
72 void
73 ieee80211_begin_bgscan(struct ifnet *ifp)
74 {
75 	struct ieee80211com *ic = (void *)ifp;
76 
77 	if ((ic->ic_flags & IEEE80211_F_BGSCAN) ||
78 	    ic->ic_state != IEEE80211_S_RUN || ic->ic_mgt_timer != 0)
79 		return;
80 
81 	if ((ic->ic_flags & IEEE80211_F_RSNON) && !ic->ic_bss->ni_port_valid)
82 		return;
83 
84 	if (ic->ic_bgscan_start != NULL && ic->ic_bgscan_start(ic) == 0) {
85 		/*
86 		 * Free the nodes table to ensure we get an up-to-date view
87 		 * of APs around us. In particular, we need to kick out the
88 		 * AP we are associated to. Otherwise, our current AP might
89 		 * stay cached if it is turned off while we are scanning, and
90 		 * we could end up picking a now non-existent AP over and over.
91 		 */
92 		ieee80211_free_allnodes(ic, 0 /* keep ic->ic_bss */);
93 
94 		ic->ic_flags |= IEEE80211_F_BGSCAN;
95 		if (ifp->if_flags & IFF_DEBUG)
96 			printf("%s: begin background scan\n", ifp->if_xname);
97 
98 		/* Driver calls ieee80211_end_scan() when done. */
99 	}
100 }
101 
102 void
103 ieee80211_bgscan_timeout(void *arg)
104 {
105 	struct ifnet *ifp = arg;
106 
107 	ieee80211_begin_bgscan(ifp);
108 }
109 
110 void
111 ieee80211_channel_init(struct ifnet *ifp)
112 {
113 	struct ieee80211com *ic = (void *)ifp;
114 	struct ieee80211_channel *c;
115 	int i;
116 
117 	/*
118 	 * Fill in 802.11 available channel set, mark
119 	 * all available channels as active, and pick
120 	 * a default channel if not already specified.
121 	 */
122 	memset(ic->ic_chan_avail, 0, sizeof(ic->ic_chan_avail));
123 	ic->ic_modecaps |= 1<<IEEE80211_MODE_AUTO;
124 	for (i = 0; i <= IEEE80211_CHAN_MAX; i++) {
125 		c = &ic->ic_channels[i];
126 		if (c->ic_flags) {
127 			/*
128 			 * Verify driver passed us valid data.
129 			 */
130 			if (i != ieee80211_chan2ieee(ic, c)) {
131 				printf("%s: bad channel ignored; "
132 					"freq %u flags %x number %u\n",
133 					ifp->if_xname, c->ic_freq, c->ic_flags,
134 					i);
135 				c->ic_flags = 0;	/* NB: remove */
136 				continue;
137 			}
138 			setbit(ic->ic_chan_avail, i);
139 			/*
140 			 * Identify mode capabilities.
141 			 */
142 			if (IEEE80211_IS_CHAN_A(c))
143 				ic->ic_modecaps |= 1<<IEEE80211_MODE_11A;
144 			if (IEEE80211_IS_CHAN_B(c))
145 				ic->ic_modecaps |= 1<<IEEE80211_MODE_11B;
146 			if (IEEE80211_IS_CHAN_PUREG(c))
147 				ic->ic_modecaps |= 1<<IEEE80211_MODE_11G;
148 			if (IEEE80211_IS_CHAN_N(c))
149 				ic->ic_modecaps |= 1<<IEEE80211_MODE_11N;
150 			if (IEEE80211_IS_CHAN_AC(c))
151 				ic->ic_modecaps |= 1<<IEEE80211_MODE_11AC;
152 		}
153 	}
154 	/* validate ic->ic_curmode */
155 	if ((ic->ic_modecaps & (1<<ic->ic_curmode)) == 0)
156 		ic->ic_curmode = IEEE80211_MODE_AUTO;
157 	ic->ic_des_chan = IEEE80211_CHAN_ANYC;	/* any channel is ok */
158 }
159 
160 void
161 ieee80211_ifattach(struct ifnet *ifp)
162 {
163 	struct ieee80211com *ic = (void *)ifp;
164 
165 	memcpy(((struct arpcom *)ifp)->ac_enaddr, ic->ic_myaddr,
166 		ETHER_ADDR_LEN);
167 	ether_ifattach(ifp);
168 
169 	ifp->if_output = ieee80211_output;
170 
171 #if NBPFILTER > 0
172 	bpfattach(&ic->ic_rawbpf, ifp, DLT_IEEE802_11,
173 	    sizeof(struct ieee80211_frame_addr4));
174 #endif
175 	ieee80211_crypto_attach(ifp);
176 
177 	ieee80211_channel_init(ifp);
178 
179 	/* IEEE 802.11 defines a MTU >= 2290 */
180 	ifp->if_capabilities |= IFCAP_VLAN_MTU;
181 
182 	ieee80211_setbasicrates(ic);
183 	(void)ieee80211_setmode(ic, ic->ic_curmode);
184 
185 	if (ic->ic_lintval == 0)
186 		ic->ic_lintval = 100;		/* default sleep */
187 	ic->ic_bmissthres = IEEE80211_BEACON_MISS_THRES;
188 	ic->ic_dtim_period = 1;	/* all TIMs are DTIMs */
189 
190 	ieee80211_node_attach(ifp);
191 	ieee80211_proto_attach(ifp);
192 
193 	if_addgroup(ifp, "wlan");
194 	ifp->if_priority = IF_WIRELESS_DEFAULT_PRIORITY;
195 
196 	ieee80211_set_link_state(ic, LINK_STATE_DOWN);
197 
198 	timeout_set(&ic->ic_bgscan_timeout, ieee80211_bgscan_timeout, ifp);
199 }
200 
201 void
202 ieee80211_ifdetach(struct ifnet *ifp)
203 {
204 	struct ieee80211com *ic = (void *)ifp;
205 
206 	timeout_del(&ic->ic_bgscan_timeout);
207 	ieee80211_proto_detach(ifp);
208 	ieee80211_crypto_detach(ifp);
209 	ieee80211_node_detach(ifp);
210 	ifmedia_delete_instance(&ic->ic_media, IFM_INST_ANY);
211 	ether_ifdetach(ifp);
212 }
213 
214 /*
215  * Convert MHz frequency to IEEE channel number.
216  */
217 u_int
218 ieee80211_mhz2ieee(u_int freq, u_int flags)
219 {
220 	if (flags & IEEE80211_CHAN_2GHZ) {	/* 2GHz band */
221 		if (freq == 2484)
222 			return 14;
223 		if (freq < 2484)
224 			return (freq - 2407) / 5;
225 		else
226 			return 15 + ((freq - 2512) / 20);
227 	} else if (flags & IEEE80211_CHAN_5GHZ) {	/* 5GHz band */
228 		return (freq - 5000) / 5;
229 	} else {				/* either, guess */
230 		if (freq == 2484)
231 			return 14;
232 		if (freq < 2484)
233 			return (freq - 2407) / 5;
234 		if (freq < 5000)
235 			return 15 + ((freq - 2512) / 20);
236 		return (freq - 5000) / 5;
237 	}
238 }
239 
240 /*
241  * Convert channel to IEEE channel number.
242  */
243 u_int
244 ieee80211_chan2ieee(struct ieee80211com *ic, const struct ieee80211_channel *c)
245 {
246 	struct ifnet *ifp = &ic->ic_if;
247 	if (ic->ic_channels <= c && c <= &ic->ic_channels[IEEE80211_CHAN_MAX])
248 		return c - ic->ic_channels;
249 	else if (c == IEEE80211_CHAN_ANYC)
250 		return IEEE80211_CHAN_ANY;
251 
252 	panic("%s: bogus channel pointer", ifp->if_xname);
253 }
254 
255 /*
256  * Convert IEEE channel number to MHz frequency.
257  */
258 u_int
259 ieee80211_ieee2mhz(u_int chan, u_int flags)
260 {
261 	if (flags & IEEE80211_CHAN_2GHZ) {	/* 2GHz band */
262 		if (chan == 14)
263 			return 2484;
264 		if (chan < 14)
265 			return 2407 + chan*5;
266 		else
267 			return 2512 + ((chan-15)*20);
268 	} else if (flags & IEEE80211_CHAN_5GHZ) {/* 5GHz band */
269 		return 5000 + (chan*5);
270 	} else {				/* either, guess */
271 		if (chan == 14)
272 			return 2484;
273 		if (chan < 14)			/* 0-13 */
274 			return 2407 + chan*5;
275 		if (chan < 27)			/* 15-26 */
276 			return 2512 + ((chan-15)*20);
277 		return 5000 + (chan*5);
278 	}
279 }
280 
281 void
282 ieee80211_configure_ampdu_tx(struct ieee80211com *ic, int enable)
283 {
284 	if ((ic->ic_caps & IEEE80211_C_TX_AMPDU) == 0)
285 		return;
286 
287 	/* Sending AMPDUs requires QoS support. */
288 	if ((ic->ic_caps & IEEE80211_C_QOS) == 0)
289 		return;
290 
291 	if (enable)
292 		ic->ic_flags |= IEEE80211_F_QOS;
293 	else
294 		ic->ic_flags &= ~IEEE80211_F_QOS;
295 }
296 
297 /*
298  * Setup the media data structures according to the channel and
299  * rate tables.  This must be called by the driver after
300  * ieee80211_attach and before most anything else.
301  */
302 void
303 ieee80211_media_init(struct ifnet *ifp,
304 	ifm_change_cb_t media_change, ifm_stat_cb_t media_stat)
305 {
306 #define	ADD(_ic, _s, _o) \
307 	ifmedia_add(&(_ic)->ic_media, \
308 		IFM_MAKEWORD(IFM_IEEE80211, (_s), (_o), 0), 0, NULL)
309 	struct ieee80211com *ic = (void *)ifp;
310 	struct ifmediareq imr;
311 	int i, j, mode, rate, maxrate, r;
312 	uint64_t mword, mopt;
313 	const struct ieee80211_rateset *rs;
314 	struct ieee80211_rateset allrates;
315 
316 	/*
317 	 * Do late attach work that must wait for any subclass
318 	 * (i.e. driver) work such as overriding methods.
319 	 */
320 	ieee80211_node_lateattach(ifp);
321 
322 	/*
323 	 * Fill in media characteristics.
324 	 */
325 	ifmedia_init(&ic->ic_media, 0, media_change, media_stat);
326 	maxrate = 0;
327 	memset(&allrates, 0, sizeof(allrates));
328 	for (mode = IEEE80211_MODE_AUTO; mode <= IEEE80211_MODE_11G; mode++) {
329 		static const uint64_t mopts[] = {
330 			IFM_AUTO,
331 			IFM_IEEE80211_11A,
332 			IFM_IEEE80211_11B,
333 			IFM_IEEE80211_11G,
334 		};
335 		if ((ic->ic_modecaps & (1<<mode)) == 0)
336 			continue;
337 		mopt = mopts[mode];
338 		ADD(ic, IFM_AUTO, mopt);	/* e.g. 11a auto */
339 #ifndef IEEE80211_STA_ONLY
340 		if (ic->ic_caps & IEEE80211_C_IBSS)
341 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_IBSS);
342 		if (ic->ic_caps & IEEE80211_C_HOSTAP)
343 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_HOSTAP);
344 		if (ic->ic_caps & IEEE80211_C_AHDEMO)
345 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_ADHOC);
346 #endif
347 		if (ic->ic_caps & IEEE80211_C_MONITOR)
348 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_MONITOR);
349 		if (mode == IEEE80211_MODE_AUTO)
350 			continue;
351 		rs = &ic->ic_sup_rates[mode];
352 		for (i = 0; i < rs->rs_nrates; i++) {
353 			rate = rs->rs_rates[i];
354 			mword = ieee80211_rate2media(ic, rate, mode);
355 			if (mword == 0)
356 				continue;
357 			ADD(ic, mword, mopt);
358 #ifndef IEEE80211_STA_ONLY
359 			if (ic->ic_caps & IEEE80211_C_IBSS)
360 				ADD(ic, mword, mopt | IFM_IEEE80211_IBSS);
361 			if (ic->ic_caps & IEEE80211_C_HOSTAP)
362 				ADD(ic, mword, mopt | IFM_IEEE80211_HOSTAP);
363 			if (ic->ic_caps & IEEE80211_C_AHDEMO)
364 				ADD(ic, mword, mopt | IFM_IEEE80211_ADHOC);
365 #endif
366 			if (ic->ic_caps & IEEE80211_C_MONITOR)
367 				ADD(ic, mword, mopt | IFM_IEEE80211_MONITOR);
368 			/*
369 			 * Add rate to the collection of all rates.
370 			 */
371 			r = rate & IEEE80211_RATE_VAL;
372 			for (j = 0; j < allrates.rs_nrates; j++)
373 				if (allrates.rs_rates[j] == r)
374 					break;
375 			if (j == allrates.rs_nrates) {
376 				/* unique, add to the set */
377 				allrates.rs_rates[j] = r;
378 				allrates.rs_nrates++;
379 			}
380 			rate = (rate & IEEE80211_RATE_VAL) / 2;
381 			if (rate > maxrate)
382 				maxrate = rate;
383 		}
384 	}
385 	for (i = 0; i < allrates.rs_nrates; i++) {
386 		mword = ieee80211_rate2media(ic, allrates.rs_rates[i],
387 				IEEE80211_MODE_AUTO);
388 		if (mword == 0)
389 			continue;
390 		mword = IFM_SUBTYPE(mword);	/* remove media options */
391 		ADD(ic, mword, 0);
392 #ifndef IEEE80211_STA_ONLY
393 		if (ic->ic_caps & IEEE80211_C_IBSS)
394 			ADD(ic, mword, IFM_IEEE80211_IBSS);
395 		if (ic->ic_caps & IEEE80211_C_HOSTAP)
396 			ADD(ic, mword, IFM_IEEE80211_HOSTAP);
397 		if (ic->ic_caps & IEEE80211_C_AHDEMO)
398 			ADD(ic, mword, IFM_IEEE80211_ADHOC);
399 #endif
400 		if (ic->ic_caps & IEEE80211_C_MONITOR)
401 			ADD(ic, mword, IFM_IEEE80211_MONITOR);
402 	}
403 
404 	if (ic->ic_modecaps & (1 << IEEE80211_MODE_11N)) {
405 		mopt = IFM_IEEE80211_11N;
406 		ADD(ic, IFM_AUTO, mopt);
407 #ifndef IEEE80211_STA_ONLY
408 		if (ic->ic_caps & IEEE80211_C_IBSS)
409 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_IBSS);
410 		if (ic->ic_caps & IEEE80211_C_HOSTAP)
411 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_HOSTAP);
412 #endif
413 		if (ic->ic_caps & IEEE80211_C_MONITOR)
414 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_MONITOR);
415 		for (i = 0; i < IEEE80211_HT_NUM_MCS; i++) {
416 			if (!isset(ic->ic_sup_mcs, i))
417 				continue;
418 			ADD(ic, IFM_IEEE80211_HT_MCS0 + i, mopt);
419 #ifndef IEEE80211_STA_ONLY
420 			if (ic->ic_caps & IEEE80211_C_IBSS)
421 				ADD(ic, IFM_IEEE80211_HT_MCS0 + i,
422 				     mopt | IFM_IEEE80211_IBSS);
423 			if (ic->ic_caps & IEEE80211_C_HOSTAP)
424 				ADD(ic, IFM_IEEE80211_HT_MCS0 + i,
425 				    mopt | IFM_IEEE80211_HOSTAP);
426 #endif
427 			if (ic->ic_caps & IEEE80211_C_MONITOR)
428 				ADD(ic, IFM_IEEE80211_HT_MCS0 + i,
429 				    mopt | IFM_IEEE80211_MONITOR);
430 		}
431 		ic->ic_flags |= IEEE80211_F_HTON; /* enable 11n by default */
432 		ieee80211_configure_ampdu_tx(ic, 1);
433 	}
434 
435 	if (ic->ic_modecaps & (1 << IEEE80211_MODE_11AC)) {
436 		mopt = IFM_IEEE80211_11AC;
437 		ADD(ic, IFM_AUTO, mopt);
438 #ifndef IEEE80211_STA_ONLY
439 		if (ic->ic_caps & IEEE80211_C_IBSS)
440 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_IBSS);
441 		if (ic->ic_caps & IEEE80211_C_HOSTAP)
442 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_HOSTAP);
443 #endif
444 		if (ic->ic_caps & IEEE80211_C_MONITOR)
445 			ADD(ic, IFM_AUTO, mopt | IFM_IEEE80211_MONITOR);
446 		for (i = 0; i < IEEE80211_VHT_NUM_MCS; i++) {
447 #if 0
448 			/* TODO: Obtain VHT MCS information from VHT CAP IE. */
449 			if (!vht_mcs_supported)
450 				continue;
451 #endif
452 			ADD(ic, IFM_IEEE80211_VHT_MCS0 + i, mopt);
453 #ifndef IEEE80211_STA_ONLY
454 			if (ic->ic_caps & IEEE80211_C_IBSS)
455 				ADD(ic, IFM_IEEE80211_VHT_MCS0 + i,
456 				     mopt | IFM_IEEE80211_IBSS);
457 			if (ic->ic_caps & IEEE80211_C_HOSTAP)
458 				ADD(ic, IFM_IEEE80211_VHT_MCS0 + i,
459 				    mopt | IFM_IEEE80211_HOSTAP);
460 #endif
461 			if (ic->ic_caps & IEEE80211_C_MONITOR)
462 				ADD(ic, IFM_IEEE80211_VHT_MCS0 + i,
463 				    mopt | IFM_IEEE80211_MONITOR);
464 		}
465 #if 0
466 		ic->ic_flags |= IEEE80211_F_VHTON; /* enable 11ac by default */
467 		if (ic->ic_caps & IEEE80211_C_QOS)
468 			ic->ic_flags |= IEEE80211_F_QOS;
469 #endif
470 	}
471 
472 	ieee80211_media_status(ifp, &imr);
473 	ifmedia_set(&ic->ic_media, imr.ifm_active);
474 
475 	if (maxrate)
476 		ifp->if_baudrate = IF_Mbps(maxrate);
477 
478 #undef ADD
479 }
480 
481 int
482 ieee80211_findrate(struct ieee80211com *ic, enum ieee80211_phymode mode,
483     int rate)
484 {
485 #define	IEEERATE(_ic,_m,_i) \
486 	((_ic)->ic_sup_rates[_m].rs_rates[_i] & IEEE80211_RATE_VAL)
487 	int i, nrates = ic->ic_sup_rates[mode].rs_nrates;
488 	for (i = 0; i < nrates; i++)
489 		if (IEEERATE(ic, mode, i) == rate)
490 			return i;
491 	return -1;
492 #undef IEEERATE
493 }
494 
495 /*
496  * Handle a media change request.
497  */
498 int
499 ieee80211_media_change(struct ifnet *ifp)
500 {
501 	struct ieee80211com *ic = (void *)ifp;
502 	struct ifmedia_entry *ime;
503 	enum ieee80211_opmode newopmode;
504 	enum ieee80211_phymode newphymode;
505 	int i, j, newrate, error = 0;
506 
507 	ime = ic->ic_media.ifm_cur;
508 	/*
509 	 * First, identify the phy mode.
510 	 */
511 	switch (IFM_MODE(ime->ifm_media)) {
512 	case IFM_IEEE80211_11A:
513 		newphymode = IEEE80211_MODE_11A;
514 		break;
515 	case IFM_IEEE80211_11B:
516 		newphymode = IEEE80211_MODE_11B;
517 		break;
518 	case IFM_IEEE80211_11G:
519 		newphymode = IEEE80211_MODE_11G;
520 		break;
521 	case IFM_IEEE80211_11N:
522 		newphymode = IEEE80211_MODE_11N;
523 		break;
524 	case IFM_IEEE80211_11AC:
525 		newphymode = IEEE80211_MODE_11AC;
526 		break;
527 	case IFM_AUTO:
528 		newphymode = IEEE80211_MODE_AUTO;
529 		break;
530 	default:
531 		return EINVAL;
532 	}
533 
534 	/*
535 	 * Validate requested mode is available.
536 	 */
537 	if ((ic->ic_modecaps & (1<<newphymode)) == 0)
538 		return EINVAL;
539 
540 	/*
541 	 * Next, the fixed/variable rate.
542 	 */
543 	i = -1;
544 	if (IFM_SUBTYPE(ime->ifm_media) >= IFM_IEEE80211_VHT_MCS0 &&
545 	    IFM_SUBTYPE(ime->ifm_media) <= IFM_IEEE80211_VHT_MCS9) {
546 		if ((ic->ic_modecaps & (1 << IEEE80211_MODE_11AC)) == 0)
547 			return EINVAL;
548 		if (newphymode != IEEE80211_MODE_AUTO &&
549 		    newphymode != IEEE80211_MODE_11AC)
550 			return EINVAL;
551 		i = ieee80211_media2mcs(ime->ifm_media);
552 		/* TODO: Obtain VHT MCS information from VHT CAP IE. */
553 		if (i == -1 /* || !vht_mcs_supported */)
554 			return EINVAL;
555 	} else if (IFM_SUBTYPE(ime->ifm_media) >= IFM_IEEE80211_HT_MCS0 &&
556 	    IFM_SUBTYPE(ime->ifm_media) <= IFM_IEEE80211_HT_MCS76) {
557 		if ((ic->ic_modecaps & (1 << IEEE80211_MODE_11N)) == 0)
558 			return EINVAL;
559 		if (newphymode != IEEE80211_MODE_AUTO &&
560 		    newphymode != IEEE80211_MODE_11N)
561 			return EINVAL;
562 		i = ieee80211_media2mcs(ime->ifm_media);
563 		if (i == -1 || isclr(ic->ic_sup_mcs, i))
564 			return EINVAL;
565 	} else if (IFM_SUBTYPE(ime->ifm_media) != IFM_AUTO) {
566 		/*
567 		 * Convert media subtype to rate.
568 		 */
569 		newrate = ieee80211_media2rate(ime->ifm_media);
570 		if (newrate == 0)
571 			return EINVAL;
572 		/*
573 		 * Check the rate table for the specified/current phy.
574 		 */
575 		if (newphymode == IEEE80211_MODE_AUTO) {
576 			/*
577 			 * In autoselect mode search for the rate.
578 			 */
579 			for (j = IEEE80211_MODE_11A;
580 			     j < IEEE80211_MODE_MAX; j++) {
581 				if ((ic->ic_modecaps & (1<<j)) == 0)
582 					continue;
583 				i = ieee80211_findrate(ic, j, newrate);
584 				if (i != -1) {
585 					/* lock mode too */
586 					newphymode = j;
587 					break;
588 				}
589 			}
590 		} else {
591 			i = ieee80211_findrate(ic, newphymode, newrate);
592 		}
593 		if (i == -1)			/* mode/rate mismatch */
594 			return EINVAL;
595 	}
596 	/* NB: defer rate setting to later */
597 
598 	/*
599 	 * Deduce new operating mode but don't install it just yet.
600 	 */
601 #ifndef IEEE80211_STA_ONLY
602 	if (ime->ifm_media & IFM_IEEE80211_ADHOC)
603 		newopmode = IEEE80211_M_AHDEMO;
604 	else if (ime->ifm_media & IFM_IEEE80211_HOSTAP)
605 		newopmode = IEEE80211_M_HOSTAP;
606 	else if (ime->ifm_media & IFM_IEEE80211_IBSS)
607 		newopmode = IEEE80211_M_IBSS;
608 	else
609 #endif
610 	if (ime->ifm_media & IFM_IEEE80211_MONITOR)
611 		newopmode = IEEE80211_M_MONITOR;
612 	else
613 		newopmode = IEEE80211_M_STA;
614 
615 #ifndef IEEE80211_STA_ONLY
616 	/*
617 	 * Autoselect doesn't make sense when operating as an AP.
618 	 * If no phy mode has been selected, pick one and lock it
619 	 * down so rate tables can be used in forming beacon frames
620 	 * and the like.
621 	 */
622 	if (newopmode == IEEE80211_M_HOSTAP &&
623 	    newphymode == IEEE80211_MODE_AUTO) {
624 		if (ic->ic_modecaps & (1 << IEEE80211_MODE_11AC))
625 			newphymode = IEEE80211_MODE_11AC;
626 		else if (ic->ic_modecaps & (1 << IEEE80211_MODE_11N))
627 			newphymode = IEEE80211_MODE_11N;
628 		else if (ic->ic_modecaps & (1 << IEEE80211_MODE_11A))
629 			newphymode = IEEE80211_MODE_11A;
630 		else if (ic->ic_modecaps & (1 << IEEE80211_MODE_11G))
631 			newphymode = IEEE80211_MODE_11G;
632 		else
633 			newphymode = IEEE80211_MODE_11B;
634 	}
635 #endif
636 
637 	/*
638 	 * Handle phy mode change.
639 	 */
640 	if (ic->ic_curmode != newphymode) {		/* change phy mode */
641 		error = ieee80211_setmode(ic, newphymode);
642 		if (error != 0)
643 			return error;
644 		error = ENETRESET;
645 	}
646 
647 	/*
648 	 * Committed to changes, install the MCS/rate setting.
649 	 */
650 	ic->ic_flags &= ~(IEEE80211_F_HTON | IEEE80211_F_VHTON);
651 	ieee80211_configure_ampdu_tx(ic, 0);
652 	if ((ic->ic_modecaps & (1 << IEEE80211_MODE_11AC)) &&
653 	    (newphymode == IEEE80211_MODE_AUTO ||
654 	    newphymode == IEEE80211_MODE_11AC)) {
655 		ic->ic_flags |= IEEE80211_F_VHTON;
656 		ieee80211_configure_ampdu_tx(ic, 1);
657 	} else if ((ic->ic_modecaps & (1 << IEEE80211_MODE_11N)) &&
658 	    (newphymode == IEEE80211_MODE_AUTO ||
659 	    newphymode == IEEE80211_MODE_11N)) {
660 		ic->ic_flags |= IEEE80211_F_HTON;
661 		ieee80211_configure_ampdu_tx(ic, 1);
662 	}
663 	if ((ic->ic_flags & (IEEE80211_F_HTON | IEEE80211_F_VHTON)) == 0) {
664 		ic->ic_fixed_mcs = -1;
665 	    	if (ic->ic_fixed_rate != i) {
666 			ic->ic_fixed_rate = i;		/* set fixed tx rate */
667 			error = ENETRESET;
668 		}
669 	} else {
670 		ic->ic_fixed_rate = -1;
671 		if (ic->ic_fixed_mcs != i) {
672 			ic->ic_fixed_mcs = i;		/* set fixed mcs */
673 			error = ENETRESET;
674 		}
675 	}
676 
677 	/*
678 	 * Handle operating mode change.
679 	 */
680 	if (ic->ic_opmode != newopmode) {
681 		ic->ic_opmode = newopmode;
682 #ifndef IEEE80211_STA_ONLY
683 		switch (newopmode) {
684 		case IEEE80211_M_AHDEMO:
685 		case IEEE80211_M_HOSTAP:
686 		case IEEE80211_M_STA:
687 		case IEEE80211_M_MONITOR:
688 			ic->ic_flags &= ~IEEE80211_F_IBSSON;
689 			break;
690 		case IEEE80211_M_IBSS:
691 			ic->ic_flags |= IEEE80211_F_IBSSON;
692 			break;
693 		}
694 #endif
695 		/*
696 		 * Yech, slot time may change depending on the
697 		 * operating mode so reset it to be sure everything
698 		 * is setup appropriately.
699 		 */
700 		ieee80211_reset_erp(ic);
701 		error = ENETRESET;
702 	}
703 #ifdef notdef
704 	if (error == 0)
705 		ifp->if_baudrate = ifmedia_baudrate(ime->ifm_media);
706 #endif
707 	return error;
708 }
709 
710 void
711 ieee80211_media_status(struct ifnet *ifp, struct ifmediareq *imr)
712 {
713 	struct ieee80211com *ic = (void *)ifp;
714 	const struct ieee80211_node *ni = NULL;
715 
716 	imr->ifm_status = IFM_AVALID;
717 	imr->ifm_active = IFM_IEEE80211;
718 	if (ic->ic_state == IEEE80211_S_RUN &&
719 	    (ic->ic_opmode != IEEE80211_M_STA ||
720 	     !(ic->ic_flags & IEEE80211_F_RSNON) ||
721 	     ic->ic_bss->ni_port_valid))
722 		imr->ifm_status |= IFM_ACTIVE;
723 	imr->ifm_active |= IFM_AUTO;
724 	switch (ic->ic_opmode) {
725 	case IEEE80211_M_STA:
726 		ni = ic->ic_bss;
727 		if (ic->ic_curmode == IEEE80211_MODE_11N ||
728 		    ic->ic_curmode == IEEE80211_MODE_11AC)
729 			imr->ifm_active |= ieee80211_mcs2media(ic,
730 				ni->ni_txmcs, ic->ic_curmode);
731 		else
732 			/* calculate rate subtype */
733 			imr->ifm_active |= ieee80211_rate2media(ic,
734 				ni->ni_rates.rs_rates[ni->ni_txrate],
735 				ic->ic_curmode);
736 		break;
737 #ifndef IEEE80211_STA_ONLY
738 	case IEEE80211_M_IBSS:
739 		imr->ifm_active |= IFM_IEEE80211_IBSS;
740 		break;
741 	case IEEE80211_M_AHDEMO:
742 		imr->ifm_active |= IFM_IEEE80211_ADHOC;
743 		break;
744 	case IEEE80211_M_HOSTAP:
745 		imr->ifm_active |= IFM_IEEE80211_HOSTAP;
746 		break;
747 #endif
748 	case IEEE80211_M_MONITOR:
749 		imr->ifm_active |= IFM_IEEE80211_MONITOR;
750 		break;
751 	default:
752 		break;
753 	}
754 	switch (ic->ic_curmode) {
755 	case IEEE80211_MODE_11A:
756 		imr->ifm_active |= IFM_IEEE80211_11A;
757 		break;
758 	case IEEE80211_MODE_11B:
759 		imr->ifm_active |= IFM_IEEE80211_11B;
760 		break;
761 	case IEEE80211_MODE_11G:
762 		imr->ifm_active |= IFM_IEEE80211_11G;
763 		break;
764 	case IEEE80211_MODE_11N:
765 		imr->ifm_active |= IFM_IEEE80211_11N;
766 		break;
767 	case IEEE80211_MODE_11AC:
768 		imr->ifm_active |= IFM_IEEE80211_11AC;
769 		break;
770 	}
771 }
772 
773 void
774 ieee80211_watchdog(struct ifnet *ifp)
775 {
776 	struct ieee80211com *ic = (void *)ifp;
777 
778 	if (ic->ic_mgt_timer && --ic->ic_mgt_timer == 0) {
779 		if (ic->ic_opmode == IEEE80211_M_STA &&
780 		    (ic->ic_state == IEEE80211_S_AUTH ||
781 		    ic->ic_state == IEEE80211_S_ASSOC)) {
782 			struct ieee80211_node *ni;
783 			if (ifp->if_flags & IFF_DEBUG)
784 				printf("%s: %s timed out for %s\n",
785 				    ifp->if_xname,
786 				    ic->ic_state == IEEE80211_S_ASSOC ?
787 				    "association" : "authentication",
788 				    ether_sprintf(ic->ic_bss->ni_macaddr));
789 			ni = ieee80211_find_node(ic, ic->ic_bss->ni_macaddr);
790 			if (ni)
791 				ni->ni_fails++;
792 			if (ISSET(ic->ic_flags, IEEE80211_F_AUTO_JOIN))
793 				ieee80211_deselect_ess(ic);
794 		}
795 		ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
796 	}
797 
798 	if (ic->ic_mgt_timer != 0)
799 		ifp->if_timer = 1;
800 }
801 
802 const struct ieee80211_rateset ieee80211_std_rateset_11a =
803 	{ 8, { 12, 18, 24, 36, 48, 72, 96, 108 } };
804 
805 const struct ieee80211_rateset ieee80211_std_rateset_11b =
806 	{ 4, { 2, 4, 11, 22 } };
807 
808 const struct ieee80211_rateset ieee80211_std_rateset_11g =
809 	{ 12, { 2, 4, 11, 22, 12, 18, 24, 36, 48, 72, 96, 108 } };
810 
811 const struct ieee80211_ht_rateset ieee80211_std_ratesets_11n[] = {
812 	/* MCS 0-7, 20MHz channel, no SGI */
813 	{ 8, { 13, 26, 39, 52, 78, 104, 117, 130 }, 0x000000ff, 0, 7, 0},
814 
815 	/* MCS 0-7, 20MHz channel, SGI */
816 	{ 8, { 14, 29, 43, 58, 87, 116, 130, 144 }, 0x000000ff, 0, 7, 1 },
817 
818 	/* MCS 8-15, 20MHz channel, no SGI */
819 	{ 8, { 26, 52, 78, 104, 156, 208, 234, 260 }, 0x0000ff00, 8, 15, 0 },
820 
821 	/* MCS 8-15, 20MHz channel, SGI */
822 	{ 8, { 29, 58, 87, 116, 173, 231, 261, 289 }, 0x0000ff00, 8, 15, 1 },
823 
824 	/* MCS 16-23, 20MHz channel, no SGI */
825 	{ 8, { 39, 78, 117, 156, 234, 312, 351, 390 }, 0x00ff0000, 16, 23, 0 },
826 
827 	/* MCS 16-23, 20MHz channel, SGI */
828 	{ 8, { 43, 87, 130, 173, 260, 347, 390, 433 }, 0x00ff0000, 16, 23, 1 },
829 
830 	/* MCS 24-31, 20MHz channel, no SGI */
831 	{ 8, { 52, 104, 156, 208, 312, 416, 468, 520 }, 0xff000000, 24, 31, 0 },
832 
833 	/* MCS 24-31, 20MHz channel, SGI */
834 	{ 8, { 58, 116, 173, 231, 347, 462, 520, 578 }, 0xff000000, 24, 31, 1 },
835 };
836 
837 const struct ieee80211_vht_rateset ieee80211_std_ratesets_11ac[] = {
838 	/* MCS 0-8 (MCS 9 N/A), 1 SS, 20MHz channel, no SGI */
839 	{ 9, { 13, 26, 39, 52, 78, 104, 117, 130, 156 }, 1, 0 },
840 
841 	/* MCS 0-8 (MCS 9 N/A), 1 SS, 20MHz channel, SGI */
842 	{ 9, { 14, 29, 43, 58, 87, 116, 130, 144, 174 }, 1, 1 },
843 
844 	/* MCS 0-8 (MCS 9 N/A), 2 SS, 20MHz channel, no SGI */
845 	{ 9, { 26, 52, 78, 104, 156, 208, 234, 260, 312 }, 2, 0 },
846 
847 	/* MCS 0-8 (MCS 9 N/A), 2 SS, 20MHz channel, SGI */
848 	{ 9, { 29, 58, 87, 116, 173, 231, 261, 289, 347 }, 2, 1 },
849 
850 	/* MCS 0-9, 1 SS, 40MHz channel, no SGI */
851 	{ 10, { 27, 54, 81, 108, 162, 216, 243, 270, 324, 360 }, 1, 0 },
852 
853 	/* MCS 0-9, 1 SS, 40MHz channel, SGI */
854 	{ 10, { 30, 60, 90, 120, 180, 240, 270, 300, 360, 400 }, 1, 1 },
855 
856 	/* MCS 0-9, 2 SS, 40MHz channel, no SGI */
857 	{ 10, { 54, 108, 162, 216, 324, 432, 486, 540, 648, 720 }, 2, 0 },
858 
859 	/* MCS 0-9, 2 SS, 40MHz channel, SGI */
860 	{ 10, { 60, 120, 180, 240, 360, 480, 540, 600, 720, 800 }, 2, 1 },
861 
862 	/* MCS 0-9, 1 SS, 80MHz channel, no SGI */
863 	{ 10, { 59, 117, 176, 234, 351, 468, 527, 585, 702, 780 }, 1, 0 },
864 
865 	/* MCS 0-9, 1 SS, 80MHz channel, SGI */
866 	{ 10, { 65, 130, 195, 260, 390, 520, 585, 650, 780, 867 }, 1, 1 },
867 
868 	/* MCS 0-9, 2 SS, 80MHz channel, no SGI */
869 	{ 10, { 117, 234, 351, 468, 702, 936, 1053, 1404, 1560 }, 2, 0 },
870 
871 	/* MCS 0-9, 2 SS, 80MHz channel, SGI */
872 	{ 10, { 130, 260, 390, 520, 780, 1040, 1170, 1300, 1560, 1734 }, 2, 1 },
873 };
874 
875 /*
876  * Mark the basic rates for the 11g rate table based on the
877  * operating mode.  For real 11g we mark all the 11b rates
878  * and 6, 12, and 24 OFDM.  For 11b compatibility we mark only
879  * 11b rates.  There's also a pseudo 11a-mode used to mark only
880  * the basic OFDM rates.
881  */
882 void
883 ieee80211_setbasicrates(struct ieee80211com *ic)
884 {
885 	static const struct ieee80211_rateset basic[] = {
886 	    { 0 },				/* IEEE80211_MODE_AUTO */
887 	    { 3, { 12, 24, 48 } },		/* IEEE80211_MODE_11A */
888 	    { 2, { 2, 4 } },			/* IEEE80211_MODE_11B */
889 	    { 4, { 2, 4, 11, 22 } },		/* IEEE80211_MODE_11G */
890 	    { 0 },				/* IEEE80211_MODE_11N	*/
891 	    { 0 },				/* IEEE80211_MODE_11AC	*/
892 	};
893 	enum ieee80211_phymode mode;
894 	struct ieee80211_rateset *rs;
895 	int i, j;
896 
897 	for (mode = 0; mode < IEEE80211_MODE_MAX; mode++) {
898 		rs = &ic->ic_sup_rates[mode];
899 		for (i = 0; i < rs->rs_nrates; i++) {
900 			rs->rs_rates[i] &= IEEE80211_RATE_VAL;
901 			for (j = 0; j < basic[mode].rs_nrates; j++) {
902 				if (basic[mode].rs_rates[j] ==
903 				    rs->rs_rates[i]) {
904 					rs->rs_rates[i] |=
905 					    IEEE80211_RATE_BASIC;
906 					break;
907 				}
908 			}
909 		}
910 	}
911 }
912 
913 int
914 ieee80211_min_basic_rate(struct ieee80211com *ic)
915 {
916 	struct ieee80211_rateset *rs = &ic->ic_bss->ni_rates;
917 	int i, min, rval;
918 
919 	min = -1;
920 
921 	for (i = 0; i < rs->rs_nrates; i++) {
922 		if ((rs->rs_rates[i] & IEEE80211_RATE_BASIC) == 0)
923 			continue;
924 		rval = (rs->rs_rates[i] & IEEE80211_RATE_VAL);
925 		if (min == -1)
926 			min = rval;
927 		else if (rval < min)
928 			min = rval;
929 	}
930 
931 	/* Default to 1 Mbit/s on 2GHz and 6 Mbit/s on 5GHz. */
932 	if (min == -1)
933 		min = IEEE80211_IS_CHAN_2GHZ(ic->ic_bss->ni_chan) ? 2 : 12;
934 
935 	return min;
936 }
937 
938 int
939 ieee80211_max_basic_rate(struct ieee80211com *ic)
940 {
941 	struct ieee80211_rateset *rs = &ic->ic_bss->ni_rates;
942 	int i, max, rval;
943 
944 	/* Default to 1 Mbit/s on 2GHz and 6 Mbit/s on 5GHz. */
945 	max = IEEE80211_IS_CHAN_2GHZ(ic->ic_bss->ni_chan) ? 2 : 12;
946 
947 	for (i = 0; i < rs->rs_nrates; i++) {
948 		if ((rs->rs_rates[i] & IEEE80211_RATE_BASIC) == 0)
949 			continue;
950 		rval = (rs->rs_rates[i] & IEEE80211_RATE_VAL);
951 		if (rval > max)
952 			max = rval;
953 	}
954 
955 	return max;
956 }
957 
958 /*
959  * Set the current phy mode and recalculate the active channel
960  * set based on the available channels for this mode.  Also
961  * select a new default/current channel if the current one is
962  * inappropriate for this mode.
963  */
964 int
965 ieee80211_setmode(struct ieee80211com *ic, enum ieee80211_phymode mode)
966 {
967 	struct ifnet *ifp = &ic->ic_if;
968 	static const u_int chanflags[] = {
969 		0,			/* IEEE80211_MODE_AUTO */
970 		IEEE80211_CHAN_A,	/* IEEE80211_MODE_11A */
971 		IEEE80211_CHAN_B,	/* IEEE80211_MODE_11B */
972 		IEEE80211_CHAN_PUREG,	/* IEEE80211_MODE_11G */
973 		IEEE80211_CHAN_HT,	/* IEEE80211_MODE_11N */
974 		IEEE80211_CHAN_VHT,	/* IEEE80211_MODE_11AC */
975 	};
976 	const struct ieee80211_channel *c;
977 	u_int modeflags;
978 	int i;
979 
980 	/* validate new mode */
981 	if ((ic->ic_modecaps & (1<<mode)) == 0) {
982 		DPRINTF(("mode %u not supported (caps 0x%x)\n",
983 		    mode, ic->ic_modecaps));
984 		return EINVAL;
985 	}
986 
987 	/*
988 	 * Verify at least one channel is present in the available
989 	 * channel list before committing to the new mode.
990 	 */
991 	if (mode >= nitems(chanflags))
992 		panic("%s: unexpected mode %u", __func__, mode);
993 	modeflags = chanflags[mode];
994 	for (i = 0; i <= IEEE80211_CHAN_MAX; i++) {
995 		c = &ic->ic_channels[i];
996 		if (mode == IEEE80211_MODE_AUTO) {
997 			if (c->ic_flags != 0)
998 				break;
999 		} else if ((c->ic_flags & modeflags) == modeflags)
1000 			break;
1001 	}
1002 	if (i > IEEE80211_CHAN_MAX) {
1003 		DPRINTF(("no channels found for mode %u\n", mode));
1004 		return EINVAL;
1005 	}
1006 
1007 	/*
1008 	 * Calculate the active channel set.
1009 	 */
1010 	memset(ic->ic_chan_active, 0, sizeof(ic->ic_chan_active));
1011 	for (i = 0; i <= IEEE80211_CHAN_MAX; i++) {
1012 		c = &ic->ic_channels[i];
1013 		if (mode == IEEE80211_MODE_AUTO) {
1014 			if (c->ic_flags != 0)
1015 				setbit(ic->ic_chan_active, i);
1016 		} else if ((c->ic_flags & modeflags) == modeflags)
1017 			setbit(ic->ic_chan_active, i);
1018 	}
1019 	/*
1020 	 * If no current/default channel is setup or the current
1021 	 * channel is wrong for the mode then pick the first
1022 	 * available channel from the active list.  This is likely
1023 	 * not the right one.
1024 	 */
1025 	if (ic->ic_ibss_chan == NULL || isclr(ic->ic_chan_active,
1026 	    ieee80211_chan2ieee(ic, ic->ic_ibss_chan))) {
1027 		for (i = 0; i <= IEEE80211_CHAN_MAX; i++)
1028 			if (isset(ic->ic_chan_active, i)) {
1029 				ic->ic_ibss_chan = &ic->ic_channels[i];
1030 				break;
1031 			}
1032 		if ((ic->ic_ibss_chan == NULL) || isclr(ic->ic_chan_active,
1033 		    ieee80211_chan2ieee(ic, ic->ic_ibss_chan)))
1034 			panic("Bad IBSS channel %u",
1035 			    ieee80211_chan2ieee(ic, ic->ic_ibss_chan));
1036 	}
1037 
1038 	/*
1039 	 * Reset the scan state for the new mode. This avoids scanning
1040 	 * of invalid channels, ie. 5GHz channels in 11b mode.
1041 	 */
1042 	ieee80211_reset_scan(ifp);
1043 
1044 	ic->ic_curmode = mode;
1045 	ieee80211_reset_erp(ic);	/* reset ERP state */
1046 
1047 	return 0;
1048 }
1049 
1050 enum ieee80211_phymode
1051 ieee80211_next_mode(struct ifnet *ifp)
1052 {
1053 	struct ieee80211com *ic = (void *)ifp;
1054 	uint16_t mode;
1055 
1056 	/*
1057 	 * Indicate a wrap-around if we're running in a fixed, user-specified
1058 	 * phy mode.
1059 	 */
1060 	if (IFM_MODE(ic->ic_media.ifm_cur->ifm_media) != IFM_AUTO)
1061 		return (IEEE80211_MODE_AUTO);
1062 
1063 	/*
1064 	 * Always scan in AUTO mode if the driver scans all bands.
1065 	 * The current mode might have changed during association
1066 	 * so we must reset it here.
1067 	 */
1068 	if (ic->ic_caps & IEEE80211_C_SCANALLBAND) {
1069 		ieee80211_setmode(ic, IEEE80211_MODE_AUTO);
1070 		return (ic->ic_curmode);
1071 	}
1072 
1073 	/*
1074 	 * Get the next supported mode; effectively, this alternates between
1075 	 * the 11a (5GHz) and 11b/g (2GHz) modes. What matters is that each
1076 	 * supported channel gets scanned.
1077 	 */
1078 	for (mode = ic->ic_curmode + 1; mode <= IEEE80211_MODE_MAX; mode++) {
1079 		/*
1080 		 * Skip over 11n mode. Its set of channels is the superset
1081 		 * of all channels supported by the other modes.
1082 		 */
1083 		if (mode == IEEE80211_MODE_11N)
1084 			continue;
1085 		/*
1086 		 * Skip over 11ac mode. Its set of channels is the set
1087 		 * of all channels supported by 11a.
1088 		 */
1089 		if (mode == IEEE80211_MODE_11AC)
1090 			continue;
1091 
1092 		/* Start over if we have already tried all modes. */
1093 		if (mode == IEEE80211_MODE_MAX) {
1094 			mode = IEEE80211_MODE_AUTO;
1095 			break;
1096 		}
1097 
1098 		if (ic->ic_modecaps & (1 << mode))
1099 			break;
1100 	}
1101 
1102 	if (mode != ic->ic_curmode)
1103 		ieee80211_setmode(ic, mode);
1104 
1105 	return (ic->ic_curmode);
1106 }
1107 
1108 /*
1109  * Return the phy mode for with the specified channel so the
1110  * caller can select a rate set.  This is problematic and the
1111  * work here assumes how things work elsewhere in this code.
1112  *
1113  * Because the result of this function is ultimately used to select a
1114  * rate from the rate set of the returned mode, it must return one of the
1115  * legacy 11a/b/g modes; 11n and 11ac modes use MCS instead of rate sets.
1116  */
1117 enum ieee80211_phymode
1118 ieee80211_chan2mode(struct ieee80211com *ic,
1119     const struct ieee80211_channel *chan)
1120 {
1121 	/*
1122 	 * Are we fixed in 11a/b/g mode?
1123 	 * NB: this assumes the channel would not be supplied to us
1124 	 *     unless it was already compatible with the current mode.
1125 	 */
1126 	if (ic->ic_curmode == IEEE80211_MODE_11A ||
1127 	    ic->ic_curmode == IEEE80211_MODE_11B ||
1128 	    ic->ic_curmode == IEEE80211_MODE_11G)
1129 		return ic->ic_curmode;
1130 
1131 	/* If no channel was provided, return the most suitable legacy mode. */
1132 	if (chan == IEEE80211_CHAN_ANYC) {
1133 		switch (ic->ic_curmode) {
1134 		case IEEE80211_MODE_AUTO:
1135 		case IEEE80211_MODE_11N:
1136 			if (ic->ic_modecaps & (1 << IEEE80211_MODE_11A))
1137 				return IEEE80211_MODE_11A;
1138 			if (ic->ic_modecaps & (1 << IEEE80211_MODE_11G))
1139 				return IEEE80211_MODE_11G;
1140 			return IEEE80211_MODE_11B;
1141 		case IEEE80211_MODE_11AC:
1142 			return IEEE80211_MODE_11A;
1143 		default:
1144 			return ic->ic_curmode;
1145 		}
1146 	}
1147 
1148 	/* Deduce a legacy mode based on the channel characteristics. */
1149 	if (IEEE80211_IS_CHAN_5GHZ(chan))
1150 		return IEEE80211_MODE_11A;
1151 	else if (chan->ic_flags & (IEEE80211_CHAN_OFDM|IEEE80211_CHAN_DYN))
1152 		return IEEE80211_MODE_11G;
1153 	else
1154 		return IEEE80211_MODE_11B;
1155 }
1156 
1157 /*
1158  * Convert IEEE80211 MCS index to ifmedia subtype.
1159  */
1160 uint64_t
1161 ieee80211_mcs2media(struct ieee80211com *ic, int mcs,
1162     enum ieee80211_phymode mode)
1163 {
1164 	switch (mode) {
1165 	case IEEE80211_MODE_11A:
1166 	case IEEE80211_MODE_11B:
1167 	case IEEE80211_MODE_11G:
1168 		/* these modes use rates, not MCS */
1169 		panic("%s: unexpected mode %d", __func__, mode);
1170 		break;
1171 	case IEEE80211_MODE_11N:
1172 		if (mcs >= 0 && mcs < IEEE80211_HT_NUM_MCS)
1173 			return (IFM_IEEE80211_11N |
1174 			    (IFM_IEEE80211_HT_MCS0 + mcs));
1175 		break;
1176 	case IEEE80211_MODE_11AC:
1177 		if (mcs >= 0 && mcs < IEEE80211_VHT_NUM_MCS)
1178 			return (IFM_IEEE80211_11AC |
1179 			    (IFM_IEEE80211_VHT_MCS0 + mcs));
1180 		break;
1181 	case IEEE80211_MODE_AUTO:
1182 		break;
1183 	}
1184 
1185 	return IFM_AUTO;
1186 }
1187 
1188 /*
1189  * Convert ifmedia subtype to IEEE80211 MCS index.
1190  */
1191 int
1192 ieee80211_media2mcs(uint64_t mword)
1193 {
1194 	uint64_t subtype;
1195 
1196 	subtype = IFM_SUBTYPE(mword);
1197 
1198 	if (subtype == IFM_AUTO)
1199 		return -1;
1200 	else if (subtype == IFM_MANUAL || subtype == IFM_NONE)
1201 		return 0;
1202 
1203 	if (subtype >= IFM_IEEE80211_HT_MCS0 &&
1204 	    subtype <= IFM_IEEE80211_HT_MCS76)
1205 		return (int)(subtype - IFM_IEEE80211_HT_MCS0);
1206 
1207 	if (subtype >= IFM_IEEE80211_VHT_MCS0 &&
1208 	    subtype <= IFM_IEEE80211_VHT_MCS9)
1209 		return (int)(subtype - IFM_IEEE80211_VHT_MCS0);
1210 
1211 	return -1;
1212 }
1213 
1214 /*
1215  * convert IEEE80211 rate value to ifmedia subtype.
1216  * ieee80211 rate is in unit of 0.5Mbps.
1217  */
1218 uint64_t
1219 ieee80211_rate2media(struct ieee80211com *ic, int rate,
1220     enum ieee80211_phymode mode)
1221 {
1222 	static const struct {
1223 		uint64_t	m;	/* rate + mode */
1224 		uint64_t	r;	/* if_media rate */
1225 	} rates[] = {
1226 		{   2 | IFM_IEEE80211_11B, IFM_IEEE80211_DS1 },
1227 		{   4 | IFM_IEEE80211_11B, IFM_IEEE80211_DS2 },
1228 		{  11 | IFM_IEEE80211_11B, IFM_IEEE80211_DS5 },
1229 		{  22 | IFM_IEEE80211_11B, IFM_IEEE80211_DS11 },
1230 		{  44 | IFM_IEEE80211_11B, IFM_IEEE80211_DS22 },
1231 		{  12 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM6 },
1232 		{  18 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM9 },
1233 		{  24 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM12 },
1234 		{  36 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM18 },
1235 		{  48 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM24 },
1236 		{  72 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM36 },
1237 		{  96 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM48 },
1238 		{ 108 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM54 },
1239 		{   2 | IFM_IEEE80211_11G, IFM_IEEE80211_DS1 },
1240 		{   4 | IFM_IEEE80211_11G, IFM_IEEE80211_DS2 },
1241 		{  11 | IFM_IEEE80211_11G, IFM_IEEE80211_DS5 },
1242 		{  22 | IFM_IEEE80211_11G, IFM_IEEE80211_DS11 },
1243 		{  12 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM6 },
1244 		{  18 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM9 },
1245 		{  24 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM12 },
1246 		{  36 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM18 },
1247 		{  48 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM24 },
1248 		{  72 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM36 },
1249 		{  96 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM48 },
1250 		{ 108 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM54 },
1251 		/* NB: OFDM72 doesn't really exist so we don't handle it */
1252 	};
1253 	uint64_t mask;
1254 	int i;
1255 
1256 	mask = rate & IEEE80211_RATE_VAL;
1257 	switch (mode) {
1258 	case IEEE80211_MODE_11A:
1259 		mask |= IFM_IEEE80211_11A;
1260 		break;
1261 	case IEEE80211_MODE_11B:
1262 		mask |= IFM_IEEE80211_11B;
1263 		break;
1264 	case IEEE80211_MODE_AUTO:
1265 		/* NB: hack, 11g matches both 11b+11a rates */
1266 		/* FALLTHROUGH */
1267 	case IEEE80211_MODE_11G:
1268 		mask |= IFM_IEEE80211_11G;
1269 		break;
1270 	case IEEE80211_MODE_11N:
1271 	case IEEE80211_MODE_11AC:
1272 		/* 11n/11ac uses MCS, not rates. */
1273 		panic("%s: unexpected mode %d", __func__, mode);
1274 		break;
1275 	}
1276 	for (i = 0; i < nitems(rates); i++)
1277 		if (rates[i].m == mask)
1278 			return rates[i].r;
1279 	return IFM_AUTO;
1280 }
1281 
1282 int
1283 ieee80211_media2rate(uint64_t mword)
1284 {
1285 	int i;
1286 	static const struct {
1287 		uint64_t subtype;
1288 		int rate;
1289 	} ieeerates[] = {
1290 		{ IFM_AUTO,		-1	},
1291 		{ IFM_MANUAL,		0	},
1292 		{ IFM_NONE,		0	},
1293 		{ IFM_IEEE80211_DS1,	2	},
1294 		{ IFM_IEEE80211_DS2,	4	},
1295 		{ IFM_IEEE80211_DS5,	11	},
1296 		{ IFM_IEEE80211_DS11,	22	},
1297 		{ IFM_IEEE80211_DS22,	44	},
1298 		{ IFM_IEEE80211_OFDM6,	12	},
1299 		{ IFM_IEEE80211_OFDM9,	18	},
1300 		{ IFM_IEEE80211_OFDM12,	24	},
1301 		{ IFM_IEEE80211_OFDM18,	36	},
1302 		{ IFM_IEEE80211_OFDM24,	48	},
1303 		{ IFM_IEEE80211_OFDM36,	72	},
1304 		{ IFM_IEEE80211_OFDM48,	96	},
1305 		{ IFM_IEEE80211_OFDM54,	108	},
1306 		{ IFM_IEEE80211_OFDM72,	144	},
1307 	};
1308 	for (i = 0; i < nitems(ieeerates); i++) {
1309 		if (ieeerates[i].subtype == IFM_SUBTYPE(mword))
1310 			return ieeerates[i].rate;
1311 	}
1312 	return 0;
1313 }
1314 
1315 /*
1316  * Convert bit rate (in 0.5Mbps units) to PLCP signal (R4-R1) and vice versa.
1317  */
1318 u_int8_t
1319 ieee80211_rate2plcp(u_int8_t rate, enum ieee80211_phymode mode)
1320 {
1321 	rate &= IEEE80211_RATE_VAL;
1322 
1323 	if (mode == IEEE80211_MODE_11B) {
1324 		/* IEEE Std 802.11b-1999 page 15, subclause 18.2.3.3 */
1325 		switch (rate) {
1326 		case 2:		return 10;
1327 		case 4:		return 20;
1328 		case 11:	return 55;
1329 		case 22:	return 110;
1330 		/* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */
1331 		case 44:	return 220;
1332 		}
1333 	} else if (mode == IEEE80211_MODE_11G || mode == IEEE80211_MODE_11A) {
1334 		/* IEEE Std 802.11a-1999 page 14, subclause 17.3.4.1 */
1335 		switch (rate) {
1336 		case 12:	return 0x0b;
1337 		case 18:	return 0x0f;
1338 		case 24:	return 0x0a;
1339 		case 36:	return 0x0e;
1340 		case 48:	return 0x09;
1341 		case 72:	return 0x0d;
1342 		case 96:	return 0x08;
1343 		case 108:	return 0x0c;
1344 		}
1345         } else
1346 		panic("%s: unexpected mode %u", __func__, mode);
1347 
1348 	DPRINTF(("unsupported rate %u\n", rate));
1349 
1350 	return 0;
1351 }
1352 
1353 u_int8_t
1354 ieee80211_plcp2rate(u_int8_t plcp, enum ieee80211_phymode mode)
1355 {
1356 	if (mode == IEEE80211_MODE_11B) {
1357 		/* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */
1358 		switch (plcp) {
1359 		case 10:	return 2;
1360 		case 20:	return 4;
1361 		case 55:	return 11;
1362 		case 110:	return 22;
1363 		/* IEEE Std 802.11g-2003 page 19, subclause 19.3.2.1 */
1364 		case 220:	return 44;
1365 		}
1366 	} else if (mode == IEEE80211_MODE_11G || mode == IEEE80211_MODE_11A) {
1367 		/* IEEE Std 802.11a-1999 page 14, subclause 17.3.4.1 */
1368 		switch (plcp) {
1369 		case 0x0b:	return 12;
1370 		case 0x0f:	return 18;
1371 		case 0x0a:	return 24;
1372 		case 0x0e:	return 36;
1373 		case 0x09:	return 48;
1374 		case 0x0d:	return 72;
1375 		case 0x08:	return 96;
1376 		case 0x0c:	return 108;
1377 		}
1378 	} else
1379 		panic("%s: unexpected mode %u", __func__, mode);
1380 
1381 	DPRINTF(("unsupported plcp %u\n", plcp));
1382 
1383 	return 0;
1384 }
1385