xref: /freebsd/sys/net80211/ieee80211.c (revision eb6d21b4ca6d668cf89afd99eef7baeafa712197)
1 /*-
2  * Copyright (c) 2001 Atsushi Onoe
3  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 /*
31  * IEEE 802.11 generic handler
32  */
33 #include "opt_wlan.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 
39 #include <sys/socket.h>
40 
41 #include <net/if.h>
42 #include <net/if_dl.h>
43 #include <net/if_media.h>
44 #include <net/if_types.h>
45 #include <net/ethernet.h>
46 
47 #include <net80211/ieee80211_var.h>
48 #include <net80211/ieee80211_regdomain.h>
49 #ifdef IEEE80211_SUPPORT_SUPERG
50 #include <net80211/ieee80211_superg.h>
51 #endif
52 
53 #include <net/bpf.h>
54 
55 const char *ieee80211_phymode_name[IEEE80211_MODE_MAX] = {
56 	[IEEE80211_MODE_AUTO]	  = "auto",
57 	[IEEE80211_MODE_11A]	  = "11a",
58 	[IEEE80211_MODE_11B]	  = "11b",
59 	[IEEE80211_MODE_11G]	  = "11g",
60 	[IEEE80211_MODE_FH]	  = "FH",
61 	[IEEE80211_MODE_TURBO_A]  = "turboA",
62 	[IEEE80211_MODE_TURBO_G]  = "turboG",
63 	[IEEE80211_MODE_STURBO_A] = "sturboA",
64 	[IEEE80211_MODE_HALF]	  = "half",
65 	[IEEE80211_MODE_QUARTER]  = "quarter",
66 	[IEEE80211_MODE_11NA]	  = "11na",
67 	[IEEE80211_MODE_11NG]	  = "11ng",
68 };
69 /* map ieee80211_opmode to the corresponding capability bit */
70 const int ieee80211_opcap[IEEE80211_OPMODE_MAX] = {
71 	[IEEE80211_M_IBSS]	= IEEE80211_C_IBSS,
72 	[IEEE80211_M_WDS]	= IEEE80211_C_WDS,
73 	[IEEE80211_M_STA]	= IEEE80211_C_STA,
74 	[IEEE80211_M_AHDEMO]	= IEEE80211_C_AHDEMO,
75 	[IEEE80211_M_HOSTAP]	= IEEE80211_C_HOSTAP,
76 	[IEEE80211_M_MONITOR]	= IEEE80211_C_MONITOR,
77 #ifdef IEEE80211_SUPPORT_MESH
78 	[IEEE80211_M_MBSS]	= IEEE80211_C_MBSS,
79 #endif
80 };
81 
82 static const uint8_t ieee80211broadcastaddr[IEEE80211_ADDR_LEN] =
83 	{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
84 
85 static	void ieee80211_syncflag_locked(struct ieee80211com *ic, int flag);
86 static	void ieee80211_syncflag_ht_locked(struct ieee80211com *ic, int flag);
87 static	void ieee80211_syncflag_ext_locked(struct ieee80211com *ic, int flag);
88 static	int ieee80211_media_setup(struct ieee80211com *ic,
89 		struct ifmedia *media, int caps, int addsta,
90 		ifm_change_cb_t media_change, ifm_stat_cb_t media_stat);
91 static	void ieee80211com_media_status(struct ifnet *, struct ifmediareq *);
92 static	int ieee80211com_media_change(struct ifnet *);
93 static	int media_status(enum ieee80211_opmode,
94 		const struct ieee80211_channel *);
95 
96 MALLOC_DEFINE(M_80211_VAP, "80211vap", "802.11 vap state");
97 
98 /*
99  * Default supported rates for 802.11 operation (in IEEE .5Mb units).
100  */
101 #define	B(r)	((r) | IEEE80211_RATE_BASIC)
102 static const struct ieee80211_rateset ieee80211_rateset_11a =
103 	{ 8, { B(12), 18, B(24), 36, B(48), 72, 96, 108 } };
104 static const struct ieee80211_rateset ieee80211_rateset_half =
105 	{ 8, { B(6), 9, B(12), 18, B(24), 36, 48, 54 } };
106 static const struct ieee80211_rateset ieee80211_rateset_quarter =
107 	{ 8, { B(3), 4, B(6), 9, B(12), 18, 24, 27 } };
108 static const struct ieee80211_rateset ieee80211_rateset_11b =
109 	{ 4, { B(2), B(4), B(11), B(22) } };
110 /* NB: OFDM rates are handled specially based on mode */
111 static const struct ieee80211_rateset ieee80211_rateset_11g =
112 	{ 12, { B(2), B(4), B(11), B(22), 12, 18, 24, 36, 48, 72, 96, 108 } };
113 #undef B
114 
115 /*
116  * Fill in 802.11 available channel set, mark
117  * all available channels as active, and pick
118  * a default channel if not already specified.
119  */
120 static void
121 ieee80211_chan_init(struct ieee80211com *ic)
122 {
123 #define	DEFAULTRATES(m, def) do { \
124 	if (ic->ic_sup_rates[m].rs_nrates == 0) \
125 		ic->ic_sup_rates[m] = def; \
126 } while (0)
127 	struct ieee80211_channel *c;
128 	int i;
129 
130 	KASSERT(0 < ic->ic_nchans && ic->ic_nchans <= IEEE80211_CHAN_MAX,
131 		("invalid number of channels specified: %u", ic->ic_nchans));
132 	memset(ic->ic_chan_avail, 0, sizeof(ic->ic_chan_avail));
133 	memset(ic->ic_modecaps, 0, sizeof(ic->ic_modecaps));
134 	setbit(ic->ic_modecaps, IEEE80211_MODE_AUTO);
135 	for (i = 0; i < ic->ic_nchans; i++) {
136 		c = &ic->ic_channels[i];
137 		KASSERT(c->ic_flags != 0, ("channel with no flags"));
138 		/*
139 		 * Help drivers that work only with frequencies by filling
140 		 * in IEEE channel #'s if not already calculated.  Note this
141 		 * mimics similar work done in ieee80211_setregdomain when
142 		 * changing regulatory state.
143 		 */
144 		if (c->ic_ieee == 0)
145 			c->ic_ieee = ieee80211_mhz2ieee(c->ic_freq,c->ic_flags);
146 		if (IEEE80211_IS_CHAN_HT40(c) && c->ic_extieee == 0)
147 			c->ic_extieee = ieee80211_mhz2ieee(c->ic_freq +
148 			    (IEEE80211_IS_CHAN_HT40U(c) ? 20 : -20),
149 			    c->ic_flags);
150 		/* default max tx power to max regulatory */
151 		if (c->ic_maxpower == 0)
152 			c->ic_maxpower = 2*c->ic_maxregpower;
153 		setbit(ic->ic_chan_avail, c->ic_ieee);
154 		/*
155 		 * Identify mode capabilities.
156 		 */
157 		if (IEEE80211_IS_CHAN_A(c))
158 			setbit(ic->ic_modecaps, IEEE80211_MODE_11A);
159 		if (IEEE80211_IS_CHAN_B(c))
160 			setbit(ic->ic_modecaps, IEEE80211_MODE_11B);
161 		if (IEEE80211_IS_CHAN_ANYG(c))
162 			setbit(ic->ic_modecaps, IEEE80211_MODE_11G);
163 		if (IEEE80211_IS_CHAN_FHSS(c))
164 			setbit(ic->ic_modecaps, IEEE80211_MODE_FH);
165 		if (IEEE80211_IS_CHAN_108A(c))
166 			setbit(ic->ic_modecaps, IEEE80211_MODE_TURBO_A);
167 		if (IEEE80211_IS_CHAN_108G(c))
168 			setbit(ic->ic_modecaps, IEEE80211_MODE_TURBO_G);
169 		if (IEEE80211_IS_CHAN_ST(c))
170 			setbit(ic->ic_modecaps, IEEE80211_MODE_STURBO_A);
171 		if (IEEE80211_IS_CHAN_HALF(c))
172 			setbit(ic->ic_modecaps, IEEE80211_MODE_HALF);
173 		if (IEEE80211_IS_CHAN_QUARTER(c))
174 			setbit(ic->ic_modecaps, IEEE80211_MODE_QUARTER);
175 		if (IEEE80211_IS_CHAN_HTA(c))
176 			setbit(ic->ic_modecaps, IEEE80211_MODE_11NA);
177 		if (IEEE80211_IS_CHAN_HTG(c))
178 			setbit(ic->ic_modecaps, IEEE80211_MODE_11NG);
179 	}
180 	/* initialize candidate channels to all available */
181 	memcpy(ic->ic_chan_active, ic->ic_chan_avail,
182 		sizeof(ic->ic_chan_avail));
183 
184 	/* sort channel table to allow lookup optimizations */
185 	ieee80211_sort_channels(ic->ic_channels, ic->ic_nchans);
186 
187 	/* invalidate any previous state */
188 	ic->ic_bsschan = IEEE80211_CHAN_ANYC;
189 	ic->ic_prevchan = NULL;
190 	ic->ic_csa_newchan = NULL;
191 	/* arbitrarily pick the first channel */
192 	ic->ic_curchan = &ic->ic_channels[0];
193 	ic->ic_rt = ieee80211_get_ratetable(ic->ic_curchan);
194 
195 	/* fillin well-known rate sets if driver has not specified */
196 	DEFAULTRATES(IEEE80211_MODE_11B,	 ieee80211_rateset_11b);
197 	DEFAULTRATES(IEEE80211_MODE_11G,	 ieee80211_rateset_11g);
198 	DEFAULTRATES(IEEE80211_MODE_11A,	 ieee80211_rateset_11a);
199 	DEFAULTRATES(IEEE80211_MODE_TURBO_A,	 ieee80211_rateset_11a);
200 	DEFAULTRATES(IEEE80211_MODE_TURBO_G,	 ieee80211_rateset_11g);
201 	DEFAULTRATES(IEEE80211_MODE_STURBO_A,	 ieee80211_rateset_11a);
202 	DEFAULTRATES(IEEE80211_MODE_HALF,	 ieee80211_rateset_half);
203 	DEFAULTRATES(IEEE80211_MODE_QUARTER,	 ieee80211_rateset_quarter);
204 	DEFAULTRATES(IEEE80211_MODE_11NA,	 ieee80211_rateset_11a);
205 	DEFAULTRATES(IEEE80211_MODE_11NG,	 ieee80211_rateset_11g);
206 
207 	/*
208 	 * Set auto mode to reset active channel state and any desired channel.
209 	 */
210 	(void) ieee80211_setmode(ic, IEEE80211_MODE_AUTO);
211 #undef DEFAULTRATES
212 }
213 
214 static void
215 null_update_mcast(struct ifnet *ifp)
216 {
217 	if_printf(ifp, "need multicast update callback\n");
218 }
219 
220 static void
221 null_update_promisc(struct ifnet *ifp)
222 {
223 	if_printf(ifp, "need promiscuous mode update callback\n");
224 }
225 
226 static int
227 null_transmit(struct ifnet *ifp, struct mbuf *m)
228 {
229 	m_freem(m);
230 	ifp->if_oerrors++;
231 	return EACCES;		/* XXX EIO/EPERM? */
232 }
233 
234 static int
235 null_output(struct ifnet *ifp, struct mbuf *m,
236 	struct sockaddr *dst, struct route *ro)
237 {
238 	if_printf(ifp, "discard raw packet\n");
239 	return null_transmit(ifp, m);
240 }
241 
242 static void
243 null_input(struct ifnet *ifp, struct mbuf *m)
244 {
245 	if_printf(ifp, "if_input should not be called\n");
246 	m_freem(m);
247 }
248 
249 /*
250  * Attach/setup the common net80211 state.  Called by
251  * the driver on attach to prior to creating any vap's.
252  */
253 void
254 ieee80211_ifattach(struct ieee80211com *ic,
255 	const uint8_t macaddr[IEEE80211_ADDR_LEN])
256 {
257 	struct ifnet *ifp = ic->ic_ifp;
258 	struct sockaddr_dl *sdl;
259 	struct ifaddr *ifa;
260 
261 	KASSERT(ifp->if_type == IFT_IEEE80211, ("if_type %d", ifp->if_type));
262 
263 	IEEE80211_LOCK_INIT(ic, ifp->if_xname);
264 	TAILQ_INIT(&ic->ic_vaps);
265 
266 	/* Create a taskqueue for all state changes */
267 	ic->ic_tq = taskqueue_create("ic_taskq", M_WAITOK | M_ZERO,
268 	    taskqueue_thread_enqueue, &ic->ic_tq);
269 	taskqueue_start_threads(&ic->ic_tq, 1, PI_NET, "%s taskq",
270 	    ifp->if_xname);
271 	/*
272 	 * Fill in 802.11 available channel set, mark all
273 	 * available channels as active, and pick a default
274 	 * channel if not already specified.
275 	 */
276 	ieee80211_media_init(ic);
277 
278 	ic->ic_update_mcast = null_update_mcast;
279 	ic->ic_update_promisc = null_update_promisc;
280 
281 	ic->ic_hash_key = arc4random();
282 	ic->ic_bintval = IEEE80211_BINTVAL_DEFAULT;
283 	ic->ic_lintval = ic->ic_bintval;
284 	ic->ic_txpowlimit = IEEE80211_TXPOWER_MAX;
285 
286 	ieee80211_crypto_attach(ic);
287 	ieee80211_node_attach(ic);
288 	ieee80211_power_attach(ic);
289 	ieee80211_proto_attach(ic);
290 #ifdef IEEE80211_SUPPORT_SUPERG
291 	ieee80211_superg_attach(ic);
292 #endif
293 	ieee80211_ht_attach(ic);
294 	ieee80211_scan_attach(ic);
295 	ieee80211_regdomain_attach(ic);
296 	ieee80211_dfs_attach(ic);
297 
298 	ieee80211_sysctl_attach(ic);
299 
300 	ifp->if_addrlen = IEEE80211_ADDR_LEN;
301 	ifp->if_hdrlen = 0;
302 	if_attach(ifp);
303 	ifp->if_mtu = IEEE80211_MTU_MAX;
304 	ifp->if_broadcastaddr = ieee80211broadcastaddr;
305 	ifp->if_output = null_output;
306 	ifp->if_input = null_input;	/* just in case */
307 	ifp->if_resolvemulti = NULL;	/* NB: callers check */
308 
309 	ifa = ifaddr_byindex(ifp->if_index);
310 	KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
311 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
312 	sdl->sdl_type = IFT_ETHER;		/* XXX IFT_IEEE80211? */
313 	sdl->sdl_alen = IEEE80211_ADDR_LEN;
314 	IEEE80211_ADDR_COPY(LLADDR(sdl), macaddr);
315 	ifa_free(ifa);
316 }
317 
318 /*
319  * Detach net80211 state on device detach.  Tear down
320  * all vap's and reclaim all common state prior to the
321  * device state going away.  Note we may call back into
322  * driver; it must be prepared for this.
323  */
324 void
325 ieee80211_ifdetach(struct ieee80211com *ic)
326 {
327 	struct ifnet *ifp = ic->ic_ifp;
328 	struct ieee80211vap *vap;
329 
330 	if_detach(ifp);
331 
332 	while ((vap = TAILQ_FIRST(&ic->ic_vaps)) != NULL)
333 		ieee80211_vap_destroy(vap);
334 	ieee80211_waitfor_parent(ic);
335 
336 	ieee80211_sysctl_detach(ic);
337 	ieee80211_dfs_detach(ic);
338 	ieee80211_regdomain_detach(ic);
339 	ieee80211_scan_detach(ic);
340 #ifdef IEEE80211_SUPPORT_SUPERG
341 	ieee80211_superg_detach(ic);
342 #endif
343 	ieee80211_ht_detach(ic);
344 	/* NB: must be called before ieee80211_node_detach */
345 	ieee80211_proto_detach(ic);
346 	ieee80211_crypto_detach(ic);
347 	ieee80211_power_detach(ic);
348 	ieee80211_node_detach(ic);
349 
350 	ifmedia_removeall(&ic->ic_media);
351 	taskqueue_free(ic->ic_tq);
352 	IEEE80211_LOCK_DESTROY(ic);
353 }
354 
355 /*
356  * Default reset method for use with the ioctl support.  This
357  * method is invoked after any state change in the 802.11
358  * layer that should be propagated to the hardware but not
359  * require re-initialization of the 802.11 state machine (e.g
360  * rescanning for an ap).  We always return ENETRESET which
361  * should cause the driver to re-initialize the device. Drivers
362  * can override this method to implement more optimized support.
363  */
364 static int
365 default_reset(struct ieee80211vap *vap, u_long cmd)
366 {
367 	return ENETRESET;
368 }
369 
370 /*
371  * Prepare a vap for use.  Drivers use this call to
372  * setup net80211 state in new vap's prior attaching
373  * them with ieee80211_vap_attach (below).
374  */
375 int
376 ieee80211_vap_setup(struct ieee80211com *ic, struct ieee80211vap *vap,
377 	const char name[IFNAMSIZ], int unit, int opmode, int flags,
378 	const uint8_t bssid[IEEE80211_ADDR_LEN],
379 	const uint8_t macaddr[IEEE80211_ADDR_LEN])
380 {
381 	struct ifnet *ifp;
382 
383 	ifp = if_alloc(IFT_ETHER);
384 	if (ifp == NULL) {
385 		if_printf(ic->ic_ifp, "%s: unable to allocate ifnet\n",
386 		    __func__);
387 		return ENOMEM;
388 	}
389 	if_initname(ifp, name, unit);
390 	ifp->if_softc = vap;			/* back pointer */
391 	ifp->if_flags = IFF_SIMPLEX | IFF_BROADCAST | IFF_MULTICAST;
392 	ifp->if_start = ieee80211_start;
393 	ifp->if_ioctl = ieee80211_ioctl;
394 	ifp->if_init = ieee80211_init;
395 	/* NB: input+output filled in by ether_ifattach */
396 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
397 	ifp->if_snd.ifq_drv_maxlen = IFQ_MAXLEN;
398 	IFQ_SET_READY(&ifp->if_snd);
399 
400 	vap->iv_ifp = ifp;
401 	vap->iv_ic = ic;
402 	vap->iv_flags = ic->ic_flags;		/* propagate common flags */
403 	vap->iv_flags_ext = ic->ic_flags_ext;
404 	vap->iv_flags_ven = ic->ic_flags_ven;
405 	vap->iv_caps = ic->ic_caps &~ IEEE80211_C_OPMODE;
406 	vap->iv_htcaps = ic->ic_htcaps;
407 	vap->iv_opmode = opmode;
408 	vap->iv_caps |= ieee80211_opcap[opmode];
409 	switch (opmode) {
410 	case IEEE80211_M_WDS:
411 		/*
412 		 * WDS links must specify the bssid of the far end.
413 		 * For legacy operation this is a static relationship.
414 		 * For non-legacy operation the station must associate
415 		 * and be authorized to pass traffic.  Plumbing the
416 		 * vap to the proper node happens when the vap
417 		 * transitions to RUN state.
418 		 */
419 		IEEE80211_ADDR_COPY(vap->iv_des_bssid, bssid);
420 		vap->iv_flags |= IEEE80211_F_DESBSSID;
421 		if (flags & IEEE80211_CLONE_WDSLEGACY)
422 			vap->iv_flags_ext |= IEEE80211_FEXT_WDSLEGACY;
423 		break;
424 #ifdef IEEE80211_SUPPORT_TDMA
425 	case IEEE80211_M_AHDEMO:
426 		if (flags & IEEE80211_CLONE_TDMA) {
427 			/* NB: checked before clone operation allowed */
428 			KASSERT(ic->ic_caps & IEEE80211_C_TDMA,
429 			    ("not TDMA capable, ic_caps 0x%x", ic->ic_caps));
430 			/*
431 			 * Propagate TDMA capability to mark vap; this
432 			 * cannot be removed and is used to distinguish
433 			 * regular ahdemo operation from ahdemo+tdma.
434 			 */
435 			vap->iv_caps |= IEEE80211_C_TDMA;
436 		}
437 		break;
438 #endif
439 	}
440 	/* auto-enable s/w beacon miss support */
441 	if (flags & IEEE80211_CLONE_NOBEACONS)
442 		vap->iv_flags_ext |= IEEE80211_FEXT_SWBMISS;
443 	/*
444 	 * Enable various functionality by default if we're
445 	 * capable; the driver can override us if it knows better.
446 	 */
447 	if (vap->iv_caps & IEEE80211_C_WME)
448 		vap->iv_flags |= IEEE80211_F_WME;
449 	if (vap->iv_caps & IEEE80211_C_BURST)
450 		vap->iv_flags |= IEEE80211_F_BURST;
451 	/* NB: bg scanning only makes sense for station mode right now */
452 	if (vap->iv_opmode == IEEE80211_M_STA &&
453 	    (vap->iv_caps & IEEE80211_C_BGSCAN))
454 		vap->iv_flags |= IEEE80211_F_BGSCAN;
455 	vap->iv_flags |= IEEE80211_F_DOTH;	/* XXX no cap, just ena */
456 	/* NB: DFS support only makes sense for ap mode right now */
457 	if (vap->iv_opmode == IEEE80211_M_HOSTAP &&
458 	    (vap->iv_caps & IEEE80211_C_DFS))
459 		vap->iv_flags_ext |= IEEE80211_FEXT_DFS;
460 
461 	vap->iv_des_chan = IEEE80211_CHAN_ANYC;		/* any channel is ok */
462 	vap->iv_bmissthreshold = IEEE80211_HWBMISS_DEFAULT;
463 	vap->iv_dtim_period = IEEE80211_DTIM_DEFAULT;
464 	/*
465 	 * Install a default reset method for the ioctl support;
466 	 * the driver can override this.
467 	 */
468 	vap->iv_reset = default_reset;
469 
470 	IEEE80211_ADDR_COPY(vap->iv_myaddr, macaddr);
471 
472 	ieee80211_sysctl_vattach(vap);
473 	ieee80211_crypto_vattach(vap);
474 	ieee80211_node_vattach(vap);
475 	ieee80211_power_vattach(vap);
476 	ieee80211_proto_vattach(vap);
477 #ifdef IEEE80211_SUPPORT_SUPERG
478 	ieee80211_superg_vattach(vap);
479 #endif
480 	ieee80211_ht_vattach(vap);
481 	ieee80211_scan_vattach(vap);
482 	ieee80211_regdomain_vattach(vap);
483 	ieee80211_radiotap_vattach(vap);
484 
485 	return 0;
486 }
487 
488 /*
489  * Activate a vap.  State should have been prepared with a
490  * call to ieee80211_vap_setup and by the driver.  On return
491  * from this call the vap is ready for use.
492  */
493 int
494 ieee80211_vap_attach(struct ieee80211vap *vap,
495 	ifm_change_cb_t media_change, ifm_stat_cb_t media_stat)
496 {
497 	struct ifnet *ifp = vap->iv_ifp;
498 	struct ieee80211com *ic = vap->iv_ic;
499 	struct ifmediareq imr;
500 	int maxrate;
501 
502 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE,
503 	    "%s: %s parent %s flags 0x%x flags_ext 0x%x\n",
504 	    __func__, ieee80211_opmode_name[vap->iv_opmode],
505 	    ic->ic_ifp->if_xname, vap->iv_flags, vap->iv_flags_ext);
506 
507 	/*
508 	 * Do late attach work that cannot happen until after
509 	 * the driver has had a chance to override defaults.
510 	 */
511 	ieee80211_node_latevattach(vap);
512 	ieee80211_power_latevattach(vap);
513 
514 	maxrate = ieee80211_media_setup(ic, &vap->iv_media, vap->iv_caps,
515 	    vap->iv_opmode == IEEE80211_M_STA, media_change, media_stat);
516 	ieee80211_media_status(ifp, &imr);
517 	/* NB: strip explicit mode; we're actually in autoselect */
518 	ifmedia_set(&vap->iv_media,
519 	    imr.ifm_active &~ (IFM_MMASK | IFM_IEEE80211_TURBO));
520 	if (maxrate)
521 		ifp->if_baudrate = IF_Mbps(maxrate);
522 
523 	ether_ifattach(ifp, vap->iv_myaddr);
524 	if (vap->iv_opmode == IEEE80211_M_MONITOR) {
525 		/* NB: disallow transmit */
526 		ifp->if_transmit = null_transmit;
527 		ifp->if_output = null_output;
528 	} else {
529 		/* hook output method setup by ether_ifattach */
530 		vap->iv_output = ifp->if_output;
531 		ifp->if_output = ieee80211_output;
532 	}
533 	/* NB: if_mtu set by ether_ifattach to ETHERMTU */
534 
535 	IEEE80211_LOCK(ic);
536 	TAILQ_INSERT_TAIL(&ic->ic_vaps, vap, iv_next);
537 	ieee80211_syncflag_locked(ic, IEEE80211_F_WME);
538 #ifdef IEEE80211_SUPPORT_SUPERG
539 	ieee80211_syncflag_locked(ic, IEEE80211_F_TURBOP);
540 #endif
541 	ieee80211_syncflag_locked(ic, IEEE80211_F_PCF);
542 	ieee80211_syncflag_locked(ic, IEEE80211_F_BURST);
543 	ieee80211_syncflag_ht_locked(ic, IEEE80211_FHT_HT);
544 	ieee80211_syncflag_ht_locked(ic, IEEE80211_FHT_USEHT40);
545 	ieee80211_syncifflag_locked(ic, IFF_PROMISC);
546 	ieee80211_syncifflag_locked(ic, IFF_ALLMULTI);
547 	IEEE80211_UNLOCK(ic);
548 
549 	return 1;
550 }
551 
552 /*
553  * Tear down vap state and reclaim the ifnet.
554  * The driver is assumed to have prepared for
555  * this; e.g. by turning off interrupts for the
556  * underlying device.
557  */
558 void
559 ieee80211_vap_detach(struct ieee80211vap *vap)
560 {
561 	struct ieee80211com *ic = vap->iv_ic;
562 	struct ifnet *ifp = vap->iv_ifp;
563 
564 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s parent %s\n",
565 	    __func__, ieee80211_opmode_name[vap->iv_opmode],
566 	    ic->ic_ifp->if_xname);
567 
568 	/* NB: bpfdetach is called by ether_ifdetach and claims all taps */
569 	ether_ifdetach(ifp);
570 
571 	ieee80211_stop(vap);
572 
573 	/*
574 	 * Flush any deferred vap tasks.
575 	 */
576 	ieee80211_draintask(ic, &vap->iv_nstate_task);
577 	ieee80211_draintask(ic, &vap->iv_swbmiss_task);
578 
579 	/* XXX band-aid until ifnet handles this for us */
580 	taskqueue_drain(taskqueue_swi, &ifp->if_linktask);
581 
582 	IEEE80211_LOCK(ic);
583 	KASSERT(vap->iv_state == IEEE80211_S_INIT , ("vap still running"));
584 	TAILQ_REMOVE(&ic->ic_vaps, vap, iv_next);
585 	ieee80211_syncflag_locked(ic, IEEE80211_F_WME);
586 #ifdef IEEE80211_SUPPORT_SUPERG
587 	ieee80211_syncflag_locked(ic, IEEE80211_F_TURBOP);
588 #endif
589 	ieee80211_syncflag_locked(ic, IEEE80211_F_PCF);
590 	ieee80211_syncflag_locked(ic, IEEE80211_F_BURST);
591 	ieee80211_syncflag_ht_locked(ic, IEEE80211_FHT_HT);
592 	ieee80211_syncflag_ht_locked(ic, IEEE80211_FHT_USEHT40);
593 	/* NB: this handles the bpfdetach done below */
594 	ieee80211_syncflag_ext_locked(ic, IEEE80211_FEXT_BPF);
595 	ieee80211_syncifflag_locked(ic, IFF_PROMISC);
596 	ieee80211_syncifflag_locked(ic, IFF_ALLMULTI);
597 	IEEE80211_UNLOCK(ic);
598 
599 	ifmedia_removeall(&vap->iv_media);
600 
601 	ieee80211_radiotap_vdetach(vap);
602 	ieee80211_regdomain_vdetach(vap);
603 	ieee80211_scan_vdetach(vap);
604 #ifdef IEEE80211_SUPPORT_SUPERG
605 	ieee80211_superg_vdetach(vap);
606 #endif
607 	ieee80211_ht_vdetach(vap);
608 	/* NB: must be before ieee80211_node_vdetach */
609 	ieee80211_proto_vdetach(vap);
610 	ieee80211_crypto_vdetach(vap);
611 	ieee80211_power_vdetach(vap);
612 	ieee80211_node_vdetach(vap);
613 	ieee80211_sysctl_vdetach(vap);
614 
615 	if_free(ifp);
616 }
617 
618 /*
619  * Synchronize flag bit state in the parent ifnet structure
620  * according to the state of all vap ifnet's.  This is used,
621  * for example, to handle IFF_PROMISC and IFF_ALLMULTI.
622  */
623 void
624 ieee80211_syncifflag_locked(struct ieee80211com *ic, int flag)
625 {
626 	struct ifnet *ifp = ic->ic_ifp;
627 	struct ieee80211vap *vap;
628 	int bit, oflags;
629 
630 	IEEE80211_LOCK_ASSERT(ic);
631 
632 	bit = 0;
633 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
634 		if (vap->iv_ifp->if_flags & flag) {
635 			/*
636 			 * XXX the bridge sets PROMISC but we don't want to
637 			 * enable it on the device, discard here so all the
638 			 * drivers don't need to special-case it
639 			 */
640 			if (flag == IFF_PROMISC &&
641 			    !(vap->iv_opmode == IEEE80211_M_MONITOR ||
642 			      (vap->iv_opmode == IEEE80211_M_AHDEMO &&
643 			       (vap->iv_caps & IEEE80211_C_TDMA) == 0)))
644 				continue;
645 			bit = 1;
646 			break;
647 		}
648 	oflags = ifp->if_flags;
649 	if (bit)
650 		ifp->if_flags |= flag;
651 	else
652 		ifp->if_flags &= ~flag;
653 	if ((ifp->if_flags ^ oflags) & flag) {
654 		/* XXX should we return 1/0 and let caller do this? */
655 		if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
656 			if (flag == IFF_PROMISC)
657 				ieee80211_runtask(ic, &ic->ic_promisc_task);
658 			else if (flag == IFF_ALLMULTI)
659 				ieee80211_runtask(ic, &ic->ic_mcast_task);
660 		}
661 	}
662 }
663 
664 /*
665  * Synchronize flag bit state in the com structure
666  * according to the state of all vap's.  This is used,
667  * for example, to handle state changes via ioctls.
668  */
669 static void
670 ieee80211_syncflag_locked(struct ieee80211com *ic, int flag)
671 {
672 	struct ieee80211vap *vap;
673 	int bit;
674 
675 	IEEE80211_LOCK_ASSERT(ic);
676 
677 	bit = 0;
678 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
679 		if (vap->iv_flags & flag) {
680 			bit = 1;
681 			break;
682 		}
683 	if (bit)
684 		ic->ic_flags |= flag;
685 	else
686 		ic->ic_flags &= ~flag;
687 }
688 
689 void
690 ieee80211_syncflag(struct ieee80211vap *vap, int flag)
691 {
692 	struct ieee80211com *ic = vap->iv_ic;
693 
694 	IEEE80211_LOCK(ic);
695 	if (flag < 0) {
696 		flag = -flag;
697 		vap->iv_flags &= ~flag;
698 	} else
699 		vap->iv_flags |= flag;
700 	ieee80211_syncflag_locked(ic, flag);
701 	IEEE80211_UNLOCK(ic);
702 }
703 
704 /*
705  * Synchronize flags_ht bit state in the com structure
706  * according to the state of all vap's.  This is used,
707  * for example, to handle state changes via ioctls.
708  */
709 static void
710 ieee80211_syncflag_ht_locked(struct ieee80211com *ic, int flag)
711 {
712 	struct ieee80211vap *vap;
713 	int bit;
714 
715 	IEEE80211_LOCK_ASSERT(ic);
716 
717 	bit = 0;
718 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
719 		if (vap->iv_flags_ht & flag) {
720 			bit = 1;
721 			break;
722 		}
723 	if (bit)
724 		ic->ic_flags_ht |= flag;
725 	else
726 		ic->ic_flags_ht &= ~flag;
727 }
728 
729 void
730 ieee80211_syncflag_ht(struct ieee80211vap *vap, int flag)
731 {
732 	struct ieee80211com *ic = vap->iv_ic;
733 
734 	IEEE80211_LOCK(ic);
735 	if (flag < 0) {
736 		flag = -flag;
737 		vap->iv_flags_ht &= ~flag;
738 	} else
739 		vap->iv_flags_ht |= flag;
740 	ieee80211_syncflag_ht_locked(ic, flag);
741 	IEEE80211_UNLOCK(ic);
742 }
743 
744 /*
745  * Synchronize flags_ext bit state in the com structure
746  * according to the state of all vap's.  This is used,
747  * for example, to handle state changes via ioctls.
748  */
749 static void
750 ieee80211_syncflag_ext_locked(struct ieee80211com *ic, int flag)
751 {
752 	struct ieee80211vap *vap;
753 	int bit;
754 
755 	IEEE80211_LOCK_ASSERT(ic);
756 
757 	bit = 0;
758 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
759 		if (vap->iv_flags_ext & flag) {
760 			bit = 1;
761 			break;
762 		}
763 	if (bit)
764 		ic->ic_flags_ext |= flag;
765 	else
766 		ic->ic_flags_ext &= ~flag;
767 }
768 
769 void
770 ieee80211_syncflag_ext(struct ieee80211vap *vap, int flag)
771 {
772 	struct ieee80211com *ic = vap->iv_ic;
773 
774 	IEEE80211_LOCK(ic);
775 	if (flag < 0) {
776 		flag = -flag;
777 		vap->iv_flags_ext &= ~flag;
778 	} else
779 		vap->iv_flags_ext |= flag;
780 	ieee80211_syncflag_ext_locked(ic, flag);
781 	IEEE80211_UNLOCK(ic);
782 }
783 
784 static __inline int
785 mapgsm(u_int freq, u_int flags)
786 {
787 	freq *= 10;
788 	if (flags & IEEE80211_CHAN_QUARTER)
789 		freq += 5;
790 	else if (flags & IEEE80211_CHAN_HALF)
791 		freq += 10;
792 	else
793 		freq += 20;
794 	/* NB: there is no 907/20 wide but leave room */
795 	return (freq - 906*10) / 5;
796 }
797 
798 static __inline int
799 mappsb(u_int freq, u_int flags)
800 {
801 	return 37 + ((freq * 10) + ((freq % 5) == 2 ? 5 : 0) - 49400) / 5;
802 }
803 
804 /*
805  * Convert MHz frequency to IEEE channel number.
806  */
807 int
808 ieee80211_mhz2ieee(u_int freq, u_int flags)
809 {
810 #define	IS_FREQ_IN_PSB(_freq) ((_freq) > 4940 && (_freq) < 4990)
811 	if (flags & IEEE80211_CHAN_GSM)
812 		return mapgsm(freq, flags);
813 	if (flags & IEEE80211_CHAN_2GHZ) {	/* 2GHz band */
814 		if (freq == 2484)
815 			return 14;
816 		if (freq < 2484)
817 			return ((int) freq - 2407) / 5;
818 		else
819 			return 15 + ((freq - 2512) / 20);
820 	} else if (flags & IEEE80211_CHAN_5GHZ) {	/* 5Ghz band */
821 		if (freq <= 5000) {
822 			/* XXX check regdomain? */
823 			if (IS_FREQ_IN_PSB(freq))
824 				return mappsb(freq, flags);
825 			return (freq - 4000) / 5;
826 		} else
827 			return (freq - 5000) / 5;
828 	} else {				/* either, guess */
829 		if (freq == 2484)
830 			return 14;
831 		if (freq < 2484) {
832 			if (907 <= freq && freq <= 922)
833 				return mapgsm(freq, flags);
834 			return ((int) freq - 2407) / 5;
835 		}
836 		if (freq < 5000) {
837 			if (IS_FREQ_IN_PSB(freq))
838 				return mappsb(freq, flags);
839 			else if (freq > 4900)
840 				return (freq - 4000) / 5;
841 			else
842 				return 15 + ((freq - 2512) / 20);
843 		}
844 		return (freq - 5000) / 5;
845 	}
846 #undef IS_FREQ_IN_PSB
847 }
848 
849 /*
850  * Convert channel to IEEE channel number.
851  */
852 int
853 ieee80211_chan2ieee(struct ieee80211com *ic, const struct ieee80211_channel *c)
854 {
855 	if (c == NULL) {
856 		if_printf(ic->ic_ifp, "invalid channel (NULL)\n");
857 		return 0;		/* XXX */
858 	}
859 	return (c == IEEE80211_CHAN_ANYC ?  IEEE80211_CHAN_ANY : c->ic_ieee);
860 }
861 
862 /*
863  * Convert IEEE channel number to MHz frequency.
864  */
865 u_int
866 ieee80211_ieee2mhz(u_int chan, u_int flags)
867 {
868 	if (flags & IEEE80211_CHAN_GSM)
869 		return 907 + 5 * (chan / 10);
870 	if (flags & IEEE80211_CHAN_2GHZ) {	/* 2GHz band */
871 		if (chan == 14)
872 			return 2484;
873 		if (chan < 14)
874 			return 2407 + chan*5;
875 		else
876 			return 2512 + ((chan-15)*20);
877 	} else if (flags & IEEE80211_CHAN_5GHZ) {/* 5Ghz band */
878 		if (flags & (IEEE80211_CHAN_HALF|IEEE80211_CHAN_QUARTER)) {
879 			chan -= 37;
880 			return 4940 + chan*5 + (chan % 5 ? 2 : 0);
881 		}
882 		return 5000 + (chan*5);
883 	} else {				/* either, guess */
884 		/* XXX can't distinguish PSB+GSM channels */
885 		if (chan == 14)
886 			return 2484;
887 		if (chan < 14)			/* 0-13 */
888 			return 2407 + chan*5;
889 		if (chan < 27)			/* 15-26 */
890 			return 2512 + ((chan-15)*20);
891 		return 5000 + (chan*5);
892 	}
893 }
894 
895 /*
896  * Locate a channel given a frequency+flags.  We cache
897  * the previous lookup to optimize switching between two
898  * channels--as happens with dynamic turbo.
899  */
900 struct ieee80211_channel *
901 ieee80211_find_channel(struct ieee80211com *ic, int freq, int flags)
902 {
903 	struct ieee80211_channel *c;
904 	int i;
905 
906 	flags &= IEEE80211_CHAN_ALLTURBO;
907 	c = ic->ic_prevchan;
908 	if (c != NULL && c->ic_freq == freq &&
909 	    (c->ic_flags & IEEE80211_CHAN_ALLTURBO) == flags)
910 		return c;
911 	/* brute force search */
912 	for (i = 0; i < ic->ic_nchans; i++) {
913 		c = &ic->ic_channels[i];
914 		if (c->ic_freq == freq &&
915 		    (c->ic_flags & IEEE80211_CHAN_ALLTURBO) == flags)
916 			return c;
917 	}
918 	return NULL;
919 }
920 
921 /*
922  * Locate a channel given a channel number+flags.  We cache
923  * the previous lookup to optimize switching between two
924  * channels--as happens with dynamic turbo.
925  */
926 struct ieee80211_channel *
927 ieee80211_find_channel_byieee(struct ieee80211com *ic, int ieee, int flags)
928 {
929 	struct ieee80211_channel *c;
930 	int i;
931 
932 	flags &= IEEE80211_CHAN_ALLTURBO;
933 	c = ic->ic_prevchan;
934 	if (c != NULL && c->ic_ieee == ieee &&
935 	    (c->ic_flags & IEEE80211_CHAN_ALLTURBO) == flags)
936 		return c;
937 	/* brute force search */
938 	for (i = 0; i < ic->ic_nchans; i++) {
939 		c = &ic->ic_channels[i];
940 		if (c->ic_ieee == ieee &&
941 		    (c->ic_flags & IEEE80211_CHAN_ALLTURBO) == flags)
942 			return c;
943 	}
944 	return NULL;
945 }
946 
947 static void
948 addmedia(struct ifmedia *media, int caps, int addsta, int mode, int mword)
949 {
950 #define	ADD(_ic, _s, _o) \
951 	ifmedia_add(media, \
952 		IFM_MAKEWORD(IFM_IEEE80211, (_s), (_o), 0), 0, NULL)
953 	static const u_int mopts[IEEE80211_MODE_MAX] = {
954 	    [IEEE80211_MODE_AUTO]	= IFM_AUTO,
955 	    [IEEE80211_MODE_11A]	= IFM_IEEE80211_11A,
956 	    [IEEE80211_MODE_11B]	= IFM_IEEE80211_11B,
957 	    [IEEE80211_MODE_11G]	= IFM_IEEE80211_11G,
958 	    [IEEE80211_MODE_FH]		= IFM_IEEE80211_FH,
959 	    [IEEE80211_MODE_TURBO_A]	= IFM_IEEE80211_11A|IFM_IEEE80211_TURBO,
960 	    [IEEE80211_MODE_TURBO_G]	= IFM_IEEE80211_11G|IFM_IEEE80211_TURBO,
961 	    [IEEE80211_MODE_STURBO_A]	= IFM_IEEE80211_11A|IFM_IEEE80211_TURBO,
962 	    [IEEE80211_MODE_HALF]	= IFM_IEEE80211_11A,	/* XXX */
963 	    [IEEE80211_MODE_QUARTER]	= IFM_IEEE80211_11A,	/* XXX */
964 	    [IEEE80211_MODE_11NA]	= IFM_IEEE80211_11NA,
965 	    [IEEE80211_MODE_11NG]	= IFM_IEEE80211_11NG,
966 	};
967 	u_int mopt;
968 
969 	mopt = mopts[mode];
970 	if (addsta)
971 		ADD(ic, mword, mopt);	/* STA mode has no cap */
972 	if (caps & IEEE80211_C_IBSS)
973 		ADD(media, mword, mopt | IFM_IEEE80211_ADHOC);
974 	if (caps & IEEE80211_C_HOSTAP)
975 		ADD(media, mword, mopt | IFM_IEEE80211_HOSTAP);
976 	if (caps & IEEE80211_C_AHDEMO)
977 		ADD(media, mword, mopt | IFM_IEEE80211_ADHOC | IFM_FLAG0);
978 	if (caps & IEEE80211_C_MONITOR)
979 		ADD(media, mword, mopt | IFM_IEEE80211_MONITOR);
980 	if (caps & IEEE80211_C_WDS)
981 		ADD(media, mword, mopt | IFM_IEEE80211_WDS);
982 	if (caps & IEEE80211_C_MBSS)
983 		ADD(media, mword, mopt | IFM_IEEE80211_MBSS);
984 #undef ADD
985 }
986 
987 /*
988  * Setup the media data structures according to the channel and
989  * rate tables.
990  */
991 static int
992 ieee80211_media_setup(struct ieee80211com *ic,
993 	struct ifmedia *media, int caps, int addsta,
994 	ifm_change_cb_t media_change, ifm_stat_cb_t media_stat)
995 {
996 	int i, j, mode, rate, maxrate, mword, r;
997 	const struct ieee80211_rateset *rs;
998 	struct ieee80211_rateset allrates;
999 
1000 	/*
1001 	 * Fill in media characteristics.
1002 	 */
1003 	ifmedia_init(media, 0, media_change, media_stat);
1004 	maxrate = 0;
1005 	/*
1006 	 * Add media for legacy operating modes.
1007 	 */
1008 	memset(&allrates, 0, sizeof(allrates));
1009 	for (mode = IEEE80211_MODE_AUTO; mode < IEEE80211_MODE_11NA; mode++) {
1010 		if (isclr(ic->ic_modecaps, mode))
1011 			continue;
1012 		addmedia(media, caps, addsta, mode, IFM_AUTO);
1013 		if (mode == IEEE80211_MODE_AUTO)
1014 			continue;
1015 		rs = &ic->ic_sup_rates[mode];
1016 		for (i = 0; i < rs->rs_nrates; i++) {
1017 			rate = rs->rs_rates[i];
1018 			mword = ieee80211_rate2media(ic, rate, mode);
1019 			if (mword == 0)
1020 				continue;
1021 			addmedia(media, caps, addsta, mode, mword);
1022 			/*
1023 			 * Add legacy rate to the collection of all rates.
1024 			 */
1025 			r = rate & IEEE80211_RATE_VAL;
1026 			for (j = 0; j < allrates.rs_nrates; j++)
1027 				if (allrates.rs_rates[j] == r)
1028 					break;
1029 			if (j == allrates.rs_nrates) {
1030 				/* unique, add to the set */
1031 				allrates.rs_rates[j] = r;
1032 				allrates.rs_nrates++;
1033 			}
1034 			rate = (rate & IEEE80211_RATE_VAL) / 2;
1035 			if (rate > maxrate)
1036 				maxrate = rate;
1037 		}
1038 	}
1039 	for (i = 0; i < allrates.rs_nrates; i++) {
1040 		mword = ieee80211_rate2media(ic, allrates.rs_rates[i],
1041 				IEEE80211_MODE_AUTO);
1042 		if (mword == 0)
1043 			continue;
1044 		/* NB: remove media options from mword */
1045 		addmedia(media, caps, addsta,
1046 		    IEEE80211_MODE_AUTO, IFM_SUBTYPE(mword));
1047 	}
1048 	/*
1049 	 * Add HT/11n media.  Note that we do not have enough
1050 	 * bits in the media subtype to express the MCS so we
1051 	 * use a "placeholder" media subtype and any fixed MCS
1052 	 * must be specified with a different mechanism.
1053 	 */
1054 	for (; mode <= IEEE80211_MODE_11NG; mode++) {
1055 		if (isclr(ic->ic_modecaps, mode))
1056 			continue;
1057 		addmedia(media, caps, addsta, mode, IFM_AUTO);
1058 		addmedia(media, caps, addsta, mode, IFM_IEEE80211_MCS);
1059 	}
1060 	if (isset(ic->ic_modecaps, IEEE80211_MODE_11NA) ||
1061 	    isset(ic->ic_modecaps, IEEE80211_MODE_11NG)) {
1062 		addmedia(media, caps, addsta,
1063 		    IEEE80211_MODE_AUTO, IFM_IEEE80211_MCS);
1064 		/* XXX could walk htrates */
1065 		/* XXX known array size */
1066 		if (ieee80211_htrates[15].ht40_rate_400ns > maxrate)
1067 			maxrate = ieee80211_htrates[15].ht40_rate_400ns;
1068 	}
1069 	return maxrate;
1070 }
1071 
1072 void
1073 ieee80211_media_init(struct ieee80211com *ic)
1074 {
1075 	struct ifnet *ifp = ic->ic_ifp;
1076 	int maxrate;
1077 
1078 	/* NB: this works because the structure is initialized to zero */
1079 	if (!LIST_EMPTY(&ic->ic_media.ifm_list)) {
1080 		/*
1081 		 * We are re-initializing the channel list; clear
1082 		 * the existing media state as the media routines
1083 		 * don't suppress duplicates.
1084 		 */
1085 		ifmedia_removeall(&ic->ic_media);
1086 	}
1087 	ieee80211_chan_init(ic);
1088 
1089 	/*
1090 	 * Recalculate media settings in case new channel list changes
1091 	 * the set of available modes.
1092 	 */
1093 	maxrate = ieee80211_media_setup(ic, &ic->ic_media, ic->ic_caps, 1,
1094 		ieee80211com_media_change, ieee80211com_media_status);
1095 	/* NB: strip explicit mode; we're actually in autoselect */
1096 	ifmedia_set(&ic->ic_media,
1097 	    media_status(ic->ic_opmode, ic->ic_curchan) &~
1098 		(IFM_MMASK | IFM_IEEE80211_TURBO));
1099 	if (maxrate)
1100 		ifp->if_baudrate = IF_Mbps(maxrate);
1101 
1102 	/* XXX need to propagate new media settings to vap's */
1103 }
1104 
1105 /* XXX inline or eliminate? */
1106 const struct ieee80211_rateset *
1107 ieee80211_get_suprates(struct ieee80211com *ic, const struct ieee80211_channel *c)
1108 {
1109 	/* XXX does this work for 11ng basic rates? */
1110 	return &ic->ic_sup_rates[ieee80211_chan2mode(c)];
1111 }
1112 
1113 void
1114 ieee80211_announce(struct ieee80211com *ic)
1115 {
1116 	struct ifnet *ifp = ic->ic_ifp;
1117 	int i, mode, rate, mword;
1118 	const struct ieee80211_rateset *rs;
1119 
1120 	/* NB: skip AUTO since it has no rates */
1121 	for (mode = IEEE80211_MODE_AUTO+1; mode < IEEE80211_MODE_11NA; mode++) {
1122 		if (isclr(ic->ic_modecaps, mode))
1123 			continue;
1124 		if_printf(ifp, "%s rates: ", ieee80211_phymode_name[mode]);
1125 		rs = &ic->ic_sup_rates[mode];
1126 		for (i = 0; i < rs->rs_nrates; i++) {
1127 			mword = ieee80211_rate2media(ic, rs->rs_rates[i], mode);
1128 			if (mword == 0)
1129 				continue;
1130 			rate = ieee80211_media2rate(mword);
1131 			printf("%s%d%sMbps", (i != 0 ? " " : ""),
1132 			    rate / 2, ((rate & 0x1) != 0 ? ".5" : ""));
1133 		}
1134 		printf("\n");
1135 	}
1136 	ieee80211_ht_announce(ic);
1137 }
1138 
1139 void
1140 ieee80211_announce_channels(struct ieee80211com *ic)
1141 {
1142 	const struct ieee80211_channel *c;
1143 	char type;
1144 	int i, cw;
1145 
1146 	printf("Chan  Freq  CW  RegPwr  MinPwr  MaxPwr\n");
1147 	for (i = 0; i < ic->ic_nchans; i++) {
1148 		c = &ic->ic_channels[i];
1149 		if (IEEE80211_IS_CHAN_ST(c))
1150 			type = 'S';
1151 		else if (IEEE80211_IS_CHAN_108A(c))
1152 			type = 'T';
1153 		else if (IEEE80211_IS_CHAN_108G(c))
1154 			type = 'G';
1155 		else if (IEEE80211_IS_CHAN_HT(c))
1156 			type = 'n';
1157 		else if (IEEE80211_IS_CHAN_A(c))
1158 			type = 'a';
1159 		else if (IEEE80211_IS_CHAN_ANYG(c))
1160 			type = 'g';
1161 		else if (IEEE80211_IS_CHAN_B(c))
1162 			type = 'b';
1163 		else
1164 			type = 'f';
1165 		if (IEEE80211_IS_CHAN_HT40(c) || IEEE80211_IS_CHAN_TURBO(c))
1166 			cw = 40;
1167 		else if (IEEE80211_IS_CHAN_HALF(c))
1168 			cw = 10;
1169 		else if (IEEE80211_IS_CHAN_QUARTER(c))
1170 			cw = 5;
1171 		else
1172 			cw = 20;
1173 		printf("%4d  %4d%c %2d%c %6d  %4d.%d  %4d.%d\n"
1174 			, c->ic_ieee, c->ic_freq, type
1175 			, cw
1176 			, IEEE80211_IS_CHAN_HT40U(c) ? '+' :
1177 			  IEEE80211_IS_CHAN_HT40D(c) ? '-' : ' '
1178 			, c->ic_maxregpower
1179 			, c->ic_minpower / 2, c->ic_minpower & 1 ? 5 : 0
1180 			, c->ic_maxpower / 2, c->ic_maxpower & 1 ? 5 : 0
1181 		);
1182 	}
1183 }
1184 
1185 static int
1186 media2mode(const struct ifmedia_entry *ime, uint32_t flags, uint16_t *mode)
1187 {
1188 	switch (IFM_MODE(ime->ifm_media)) {
1189 	case IFM_IEEE80211_11A:
1190 		*mode = IEEE80211_MODE_11A;
1191 		break;
1192 	case IFM_IEEE80211_11B:
1193 		*mode = IEEE80211_MODE_11B;
1194 		break;
1195 	case IFM_IEEE80211_11G:
1196 		*mode = IEEE80211_MODE_11G;
1197 		break;
1198 	case IFM_IEEE80211_FH:
1199 		*mode = IEEE80211_MODE_FH;
1200 		break;
1201 	case IFM_IEEE80211_11NA:
1202 		*mode = IEEE80211_MODE_11NA;
1203 		break;
1204 	case IFM_IEEE80211_11NG:
1205 		*mode = IEEE80211_MODE_11NG;
1206 		break;
1207 	case IFM_AUTO:
1208 		*mode = IEEE80211_MODE_AUTO;
1209 		break;
1210 	default:
1211 		return 0;
1212 	}
1213 	/*
1214 	 * Turbo mode is an ``option''.
1215 	 * XXX does not apply to AUTO
1216 	 */
1217 	if (ime->ifm_media & IFM_IEEE80211_TURBO) {
1218 		if (*mode == IEEE80211_MODE_11A) {
1219 			if (flags & IEEE80211_F_TURBOP)
1220 				*mode = IEEE80211_MODE_TURBO_A;
1221 			else
1222 				*mode = IEEE80211_MODE_STURBO_A;
1223 		} else if (*mode == IEEE80211_MODE_11G)
1224 			*mode = IEEE80211_MODE_TURBO_G;
1225 		else
1226 			return 0;
1227 	}
1228 	/* XXX HT40 +/- */
1229 	return 1;
1230 }
1231 
1232 /*
1233  * Handle a media change request on the underlying interface.
1234  */
1235 int
1236 ieee80211com_media_change(struct ifnet *ifp)
1237 {
1238 	return EINVAL;
1239 }
1240 
1241 /*
1242  * Handle a media change request on the vap interface.
1243  */
1244 int
1245 ieee80211_media_change(struct ifnet *ifp)
1246 {
1247 	struct ieee80211vap *vap = ifp->if_softc;
1248 	struct ifmedia_entry *ime = vap->iv_media.ifm_cur;
1249 	uint16_t newmode;
1250 
1251 	if (!media2mode(ime, vap->iv_flags, &newmode))
1252 		return EINVAL;
1253 	if (vap->iv_des_mode != newmode) {
1254 		vap->iv_des_mode = newmode;
1255 		/* XXX kick state machine if up+running */
1256 	}
1257 	return 0;
1258 }
1259 
1260 /*
1261  * Common code to calculate the media status word
1262  * from the operating mode and channel state.
1263  */
1264 static int
1265 media_status(enum ieee80211_opmode opmode, const struct ieee80211_channel *chan)
1266 {
1267 	int status;
1268 
1269 	status = IFM_IEEE80211;
1270 	switch (opmode) {
1271 	case IEEE80211_M_STA:
1272 		break;
1273 	case IEEE80211_M_IBSS:
1274 		status |= IFM_IEEE80211_ADHOC;
1275 		break;
1276 	case IEEE80211_M_HOSTAP:
1277 		status |= IFM_IEEE80211_HOSTAP;
1278 		break;
1279 	case IEEE80211_M_MONITOR:
1280 		status |= IFM_IEEE80211_MONITOR;
1281 		break;
1282 	case IEEE80211_M_AHDEMO:
1283 		status |= IFM_IEEE80211_ADHOC | IFM_FLAG0;
1284 		break;
1285 	case IEEE80211_M_WDS:
1286 		status |= IFM_IEEE80211_WDS;
1287 		break;
1288 	case IEEE80211_M_MBSS:
1289 		status |= IFM_IEEE80211_MBSS;
1290 		break;
1291 	}
1292 	if (IEEE80211_IS_CHAN_HTA(chan)) {
1293 		status |= IFM_IEEE80211_11NA;
1294 	} else if (IEEE80211_IS_CHAN_HTG(chan)) {
1295 		status |= IFM_IEEE80211_11NG;
1296 	} else if (IEEE80211_IS_CHAN_A(chan)) {
1297 		status |= IFM_IEEE80211_11A;
1298 	} else if (IEEE80211_IS_CHAN_B(chan)) {
1299 		status |= IFM_IEEE80211_11B;
1300 	} else if (IEEE80211_IS_CHAN_ANYG(chan)) {
1301 		status |= IFM_IEEE80211_11G;
1302 	} else if (IEEE80211_IS_CHAN_FHSS(chan)) {
1303 		status |= IFM_IEEE80211_FH;
1304 	}
1305 	/* XXX else complain? */
1306 
1307 	if (IEEE80211_IS_CHAN_TURBO(chan))
1308 		status |= IFM_IEEE80211_TURBO;
1309 #if 0
1310 	if (IEEE80211_IS_CHAN_HT20(chan))
1311 		status |= IFM_IEEE80211_HT20;
1312 	if (IEEE80211_IS_CHAN_HT40(chan))
1313 		status |= IFM_IEEE80211_HT40;
1314 #endif
1315 	return status;
1316 }
1317 
1318 static void
1319 ieee80211com_media_status(struct ifnet *ifp, struct ifmediareq *imr)
1320 {
1321 	struct ieee80211com *ic = ifp->if_l2com;
1322 	struct ieee80211vap *vap;
1323 
1324 	imr->ifm_status = IFM_AVALID;
1325 	TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
1326 		if (vap->iv_ifp->if_flags & IFF_UP) {
1327 			imr->ifm_status |= IFM_ACTIVE;
1328 			break;
1329 		}
1330 	imr->ifm_active = media_status(ic->ic_opmode, ic->ic_curchan);
1331 	if (imr->ifm_status & IFM_ACTIVE)
1332 		imr->ifm_current = imr->ifm_active;
1333 }
1334 
1335 void
1336 ieee80211_media_status(struct ifnet *ifp, struct ifmediareq *imr)
1337 {
1338 	struct ieee80211vap *vap = ifp->if_softc;
1339 	struct ieee80211com *ic = vap->iv_ic;
1340 	enum ieee80211_phymode mode;
1341 
1342 	imr->ifm_status = IFM_AVALID;
1343 	/*
1344 	 * NB: use the current channel's mode to lock down a xmit
1345 	 * rate only when running; otherwise we may have a mismatch
1346 	 * in which case the rate will not be convertible.
1347 	 */
1348 	if (vap->iv_state == IEEE80211_S_RUN) {
1349 		imr->ifm_status |= IFM_ACTIVE;
1350 		mode = ieee80211_chan2mode(ic->ic_curchan);
1351 	} else
1352 		mode = IEEE80211_MODE_AUTO;
1353 	imr->ifm_active = media_status(vap->iv_opmode, ic->ic_curchan);
1354 	/*
1355 	 * Calculate a current rate if possible.
1356 	 */
1357 	if (vap->iv_txparms[mode].ucastrate != IEEE80211_FIXED_RATE_NONE) {
1358 		/*
1359 		 * A fixed rate is set, report that.
1360 		 */
1361 		imr->ifm_active |= ieee80211_rate2media(ic,
1362 			vap->iv_txparms[mode].ucastrate, mode);
1363 	} else if (vap->iv_opmode == IEEE80211_M_STA) {
1364 		/*
1365 		 * In station mode report the current transmit rate.
1366 		 */
1367 		imr->ifm_active |= ieee80211_rate2media(ic,
1368 			vap->iv_bss->ni_txrate, mode);
1369 	} else
1370 		imr->ifm_active |= IFM_AUTO;
1371 	if (imr->ifm_status & IFM_ACTIVE)
1372 		imr->ifm_current = imr->ifm_active;
1373 }
1374 
1375 /*
1376  * Set the current phy mode and recalculate the active channel
1377  * set based on the available channels for this mode.  Also
1378  * select a new default/current channel if the current one is
1379  * inappropriate for this mode.
1380  */
1381 int
1382 ieee80211_setmode(struct ieee80211com *ic, enum ieee80211_phymode mode)
1383 {
1384 	/*
1385 	 * Adjust basic rates in 11b/11g supported rate set.
1386 	 * Note that if operating on a hal/quarter rate channel
1387 	 * this is a noop as those rates sets are different
1388 	 * and used instead.
1389 	 */
1390 	if (mode == IEEE80211_MODE_11G || mode == IEEE80211_MODE_11B)
1391 		ieee80211_setbasicrates(&ic->ic_sup_rates[mode], mode);
1392 
1393 	ic->ic_curmode = mode;
1394 	ieee80211_reset_erp(ic);	/* reset ERP state */
1395 
1396 	return 0;
1397 }
1398 
1399 /*
1400  * Return the phy mode for with the specified channel.
1401  */
1402 enum ieee80211_phymode
1403 ieee80211_chan2mode(const struct ieee80211_channel *chan)
1404 {
1405 
1406 	if (IEEE80211_IS_CHAN_HTA(chan))
1407 		return IEEE80211_MODE_11NA;
1408 	else if (IEEE80211_IS_CHAN_HTG(chan))
1409 		return IEEE80211_MODE_11NG;
1410 	else if (IEEE80211_IS_CHAN_108G(chan))
1411 		return IEEE80211_MODE_TURBO_G;
1412 	else if (IEEE80211_IS_CHAN_ST(chan))
1413 		return IEEE80211_MODE_STURBO_A;
1414 	else if (IEEE80211_IS_CHAN_TURBO(chan))
1415 		return IEEE80211_MODE_TURBO_A;
1416 	else if (IEEE80211_IS_CHAN_HALF(chan))
1417 		return IEEE80211_MODE_HALF;
1418 	else if (IEEE80211_IS_CHAN_QUARTER(chan))
1419 		return IEEE80211_MODE_QUARTER;
1420 	else if (IEEE80211_IS_CHAN_A(chan))
1421 		return IEEE80211_MODE_11A;
1422 	else if (IEEE80211_IS_CHAN_ANYG(chan))
1423 		return IEEE80211_MODE_11G;
1424 	else if (IEEE80211_IS_CHAN_B(chan))
1425 		return IEEE80211_MODE_11B;
1426 	else if (IEEE80211_IS_CHAN_FHSS(chan))
1427 		return IEEE80211_MODE_FH;
1428 
1429 	/* NB: should not get here */
1430 	printf("%s: cannot map channel to mode; freq %u flags 0x%x\n",
1431 		__func__, chan->ic_freq, chan->ic_flags);
1432 	return IEEE80211_MODE_11B;
1433 }
1434 
1435 struct ratemedia {
1436 	u_int	match;	/* rate + mode */
1437 	u_int	media;	/* if_media rate */
1438 };
1439 
1440 static int
1441 findmedia(const struct ratemedia rates[], int n, u_int match)
1442 {
1443 	int i;
1444 
1445 	for (i = 0; i < n; i++)
1446 		if (rates[i].match == match)
1447 			return rates[i].media;
1448 	return IFM_AUTO;
1449 }
1450 
1451 /*
1452  * Convert IEEE80211 rate value to ifmedia subtype.
1453  * Rate is either a legacy rate in units of 0.5Mbps
1454  * or an MCS index.
1455  */
1456 int
1457 ieee80211_rate2media(struct ieee80211com *ic, int rate, enum ieee80211_phymode mode)
1458 {
1459 #define	N(a)	(sizeof(a) / sizeof(a[0]))
1460 	static const struct ratemedia rates[] = {
1461 		{   2 | IFM_IEEE80211_FH, IFM_IEEE80211_FH1 },
1462 		{   4 | IFM_IEEE80211_FH, IFM_IEEE80211_FH2 },
1463 		{   2 | IFM_IEEE80211_11B, IFM_IEEE80211_DS1 },
1464 		{   4 | IFM_IEEE80211_11B, IFM_IEEE80211_DS2 },
1465 		{  11 | IFM_IEEE80211_11B, IFM_IEEE80211_DS5 },
1466 		{  22 | IFM_IEEE80211_11B, IFM_IEEE80211_DS11 },
1467 		{  44 | IFM_IEEE80211_11B, IFM_IEEE80211_DS22 },
1468 		{  12 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM6 },
1469 		{  18 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM9 },
1470 		{  24 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM12 },
1471 		{  36 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM18 },
1472 		{  48 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM24 },
1473 		{  72 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM36 },
1474 		{  96 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM48 },
1475 		{ 108 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM54 },
1476 		{   2 | IFM_IEEE80211_11G, IFM_IEEE80211_DS1 },
1477 		{   4 | IFM_IEEE80211_11G, IFM_IEEE80211_DS2 },
1478 		{  11 | IFM_IEEE80211_11G, IFM_IEEE80211_DS5 },
1479 		{  22 | IFM_IEEE80211_11G, IFM_IEEE80211_DS11 },
1480 		{  12 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM6 },
1481 		{  18 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM9 },
1482 		{  24 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM12 },
1483 		{  36 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM18 },
1484 		{  48 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM24 },
1485 		{  72 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM36 },
1486 		{  96 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM48 },
1487 		{ 108 | IFM_IEEE80211_11G, IFM_IEEE80211_OFDM54 },
1488 		{   6 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM3 },
1489 		{   9 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM4 },
1490 		{  54 | IFM_IEEE80211_11A, IFM_IEEE80211_OFDM27 },
1491 		/* NB: OFDM72 doesn't realy exist so we don't handle it */
1492 	};
1493 	static const struct ratemedia htrates[] = {
1494 		{   0, IFM_IEEE80211_MCS },
1495 		{   1, IFM_IEEE80211_MCS },
1496 		{   2, IFM_IEEE80211_MCS },
1497 		{   3, IFM_IEEE80211_MCS },
1498 		{   4, IFM_IEEE80211_MCS },
1499 		{   5, IFM_IEEE80211_MCS },
1500 		{   6, IFM_IEEE80211_MCS },
1501 		{   7, IFM_IEEE80211_MCS },
1502 		{   8, IFM_IEEE80211_MCS },
1503 		{   9, IFM_IEEE80211_MCS },
1504 		{  10, IFM_IEEE80211_MCS },
1505 		{  11, IFM_IEEE80211_MCS },
1506 		{  12, IFM_IEEE80211_MCS },
1507 		{  13, IFM_IEEE80211_MCS },
1508 		{  14, IFM_IEEE80211_MCS },
1509 		{  15, IFM_IEEE80211_MCS },
1510 	};
1511 	int m;
1512 
1513 	/*
1514 	 * Check 11n rates first for match as an MCS.
1515 	 */
1516 	if (mode == IEEE80211_MODE_11NA) {
1517 		if (rate & IEEE80211_RATE_MCS) {
1518 			rate &= ~IEEE80211_RATE_MCS;
1519 			m = findmedia(htrates, N(htrates), rate);
1520 			if (m != IFM_AUTO)
1521 				return m | IFM_IEEE80211_11NA;
1522 		}
1523 	} else if (mode == IEEE80211_MODE_11NG) {
1524 		/* NB: 12 is ambiguous, it will be treated as an MCS */
1525 		if (rate & IEEE80211_RATE_MCS) {
1526 			rate &= ~IEEE80211_RATE_MCS;
1527 			m = findmedia(htrates, N(htrates), rate);
1528 			if (m != IFM_AUTO)
1529 				return m | IFM_IEEE80211_11NG;
1530 		}
1531 	}
1532 	rate &= IEEE80211_RATE_VAL;
1533 	switch (mode) {
1534 	case IEEE80211_MODE_11A:
1535 	case IEEE80211_MODE_HALF:		/* XXX good 'nuf */
1536 	case IEEE80211_MODE_QUARTER:
1537 	case IEEE80211_MODE_11NA:
1538 	case IEEE80211_MODE_TURBO_A:
1539 	case IEEE80211_MODE_STURBO_A:
1540 		return findmedia(rates, N(rates), rate | IFM_IEEE80211_11A);
1541 	case IEEE80211_MODE_11B:
1542 		return findmedia(rates, N(rates), rate | IFM_IEEE80211_11B);
1543 	case IEEE80211_MODE_FH:
1544 		return findmedia(rates, N(rates), rate | IFM_IEEE80211_FH);
1545 	case IEEE80211_MODE_AUTO:
1546 		/* NB: ic may be NULL for some drivers */
1547 		if (ic != NULL && ic->ic_phytype == IEEE80211_T_FH)
1548 			return findmedia(rates, N(rates),
1549 			    rate | IFM_IEEE80211_FH);
1550 		/* NB: hack, 11g matches both 11b+11a rates */
1551 		/* fall thru... */
1552 	case IEEE80211_MODE_11G:
1553 	case IEEE80211_MODE_11NG:
1554 	case IEEE80211_MODE_TURBO_G:
1555 		return findmedia(rates, N(rates), rate | IFM_IEEE80211_11G);
1556 	}
1557 	return IFM_AUTO;
1558 #undef N
1559 }
1560 
1561 int
1562 ieee80211_media2rate(int mword)
1563 {
1564 #define	N(a)	(sizeof(a) / sizeof(a[0]))
1565 	static const int ieeerates[] = {
1566 		-1,		/* IFM_AUTO */
1567 		0,		/* IFM_MANUAL */
1568 		0,		/* IFM_NONE */
1569 		2,		/* IFM_IEEE80211_FH1 */
1570 		4,		/* IFM_IEEE80211_FH2 */
1571 		2,		/* IFM_IEEE80211_DS1 */
1572 		4,		/* IFM_IEEE80211_DS2 */
1573 		11,		/* IFM_IEEE80211_DS5 */
1574 		22,		/* IFM_IEEE80211_DS11 */
1575 		44,		/* IFM_IEEE80211_DS22 */
1576 		12,		/* IFM_IEEE80211_OFDM6 */
1577 		18,		/* IFM_IEEE80211_OFDM9 */
1578 		24,		/* IFM_IEEE80211_OFDM12 */
1579 		36,		/* IFM_IEEE80211_OFDM18 */
1580 		48,		/* IFM_IEEE80211_OFDM24 */
1581 		72,		/* IFM_IEEE80211_OFDM36 */
1582 		96,		/* IFM_IEEE80211_OFDM48 */
1583 		108,		/* IFM_IEEE80211_OFDM54 */
1584 		144,		/* IFM_IEEE80211_OFDM72 */
1585 		0,		/* IFM_IEEE80211_DS354k */
1586 		0,		/* IFM_IEEE80211_DS512k */
1587 		6,		/* IFM_IEEE80211_OFDM3 */
1588 		9,		/* IFM_IEEE80211_OFDM4 */
1589 		54,		/* IFM_IEEE80211_OFDM27 */
1590 		-1,		/* IFM_IEEE80211_MCS */
1591 	};
1592 	return IFM_SUBTYPE(mword) < N(ieeerates) ?
1593 		ieeerates[IFM_SUBTYPE(mword)] : 0;
1594 #undef N
1595 }
1596 
1597 /*
1598  * The following hash function is adapted from "Hash Functions" by Bob Jenkins
1599  * ("Algorithm Alley", Dr. Dobbs Journal, September 1997).
1600  */
1601 #define	mix(a, b, c)							\
1602 do {									\
1603 	a -= b; a -= c; a ^= (c >> 13);					\
1604 	b -= c; b -= a; b ^= (a << 8);					\
1605 	c -= a; c -= b; c ^= (b >> 13);					\
1606 	a -= b; a -= c; a ^= (c >> 12);					\
1607 	b -= c; b -= a; b ^= (a << 16);					\
1608 	c -= a; c -= b; c ^= (b >> 5);					\
1609 	a -= b; a -= c; a ^= (c >> 3);					\
1610 	b -= c; b -= a; b ^= (a << 10);					\
1611 	c -= a; c -= b; c ^= (b >> 15);					\
1612 } while (/*CONSTCOND*/0)
1613 
1614 uint32_t
1615 ieee80211_mac_hash(const struct ieee80211com *ic,
1616 	const uint8_t addr[IEEE80211_ADDR_LEN])
1617 {
1618 	uint32_t a = 0x9e3779b9, b = 0x9e3779b9, c = ic->ic_hash_key;
1619 
1620 	b += addr[5] << 8;
1621 	b += addr[4];
1622 	a += addr[3] << 24;
1623 	a += addr[2] << 16;
1624 	a += addr[1] << 8;
1625 	a += addr[0];
1626 
1627 	mix(a, b, c);
1628 
1629 	return c;
1630 }
1631 #undef mix
1632