xref: /freebsd/sys/net80211/ieee80211_scan.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 /*
32  * IEEE 802.11 scanning support.
33  */
34 #include "opt_wlan.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/proc.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/condvar.h>
42 
43 #include <sys/socket.h>
44 
45 #include <net/if.h>
46 #include <net/if_var.h>
47 #include <net/if_media.h>
48 #include <net/ethernet.h>
49 
50 #include <net80211/ieee80211_var.h>
51 
52 /* XXX until it's implemented as attach ops */
53 #include <net80211/ieee80211_scan_sw.h>
54 
55 #include <net/bpf.h>
56 
57 /*
58  * Roaming-related defaults.  RSSI thresholds are as returned by the
59  * driver (.5dBm).  Transmit rate thresholds are IEEE rate codes (i.e
60  * .5M units) or MCS.
61  */
62 /* rssi thresholds */
63 #define	ROAM_RSSI_11A_DEFAULT		14	/* 11a bss */
64 #define	ROAM_RSSI_11B_DEFAULT		14	/* 11b bss */
65 #define	ROAM_RSSI_11BONLY_DEFAULT	14	/* 11b-only bss */
66 /* transmit rate thresholds */
67 #define	ROAM_RATE_11A_DEFAULT		2*12	/* 11a bss */
68 #define	ROAM_RATE_11B_DEFAULT		2*5	/* 11b bss */
69 #define	ROAM_RATE_11BONLY_DEFAULT	2*1	/* 11b-only bss */
70 #define	ROAM_RATE_HALF_DEFAULT		2*6	/* half-width 11a/g bss */
71 #define	ROAM_RATE_QUARTER_DEFAULT	2*3	/* quarter-width 11a/g bss */
72 #define	ROAM_MCS_11N_DEFAULT		(1 | IEEE80211_RATE_MCS) /* 11n bss */
73 #define	ROAM_MCS_11AC_DEFAULT		(1 | IEEE80211_RATE_MCS) /* 11ac bss; XXX not used yet */
74 
75 void
76 ieee80211_scan_attach(struct ieee80211com *ic)
77 {
78 	/*
79 	 * If there's no scan method pointer, attach the
80 	 * swscan set as a default.
81 	 */
82 	if (ic->ic_scan_methods == NULL)
83 		ieee80211_swscan_attach(ic);
84 	else
85 		ic->ic_scan_methods->sc_attach(ic);
86 }
87 
88 void
89 ieee80211_scan_detach(struct ieee80211com *ic)
90 {
91 
92 	/*
93 	 * Ideally we'd do the ss_ops detach call here;
94 	 * but then sc_detach() would need to be split in two.
95 	 *
96 	 * I'll do that later.
97 	 */
98 	ic->ic_scan_methods->sc_detach(ic);
99 }
100 
101 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
102 	[IEEE80211_MODE_11A]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
103 				    .rate = ROAM_RATE_11A_DEFAULT },
104 	[IEEE80211_MODE_11G]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
105 				    .rate = ROAM_RATE_11B_DEFAULT },
106 	[IEEE80211_MODE_11B]	= { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
107 				    .rate = ROAM_RATE_11BONLY_DEFAULT },
108 	[IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
109 				    .rate = ROAM_RATE_11A_DEFAULT },
110 	[IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
111 				    .rate = ROAM_RATE_11A_DEFAULT },
112 	[IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
113 				    .rate = ROAM_RATE_11A_DEFAULT },
114 	[IEEE80211_MODE_HALF]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
115 				    .rate = ROAM_RATE_HALF_DEFAULT },
116 	[IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
117 				    .rate = ROAM_RATE_QUARTER_DEFAULT },
118 	[IEEE80211_MODE_11NA]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
119 				    .rate = ROAM_MCS_11N_DEFAULT },
120 	[IEEE80211_MODE_11NG]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
121 				    .rate = ROAM_MCS_11N_DEFAULT },
122 	[IEEE80211_MODE_VHT_2GHZ]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
123 				    .rate = ROAM_MCS_11AC_DEFAULT },
124 	[IEEE80211_MODE_VHT_5GHZ]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
125 				    .rate = ROAM_MCS_11AC_DEFAULT },
126 
127 };
128 
129 void
130 ieee80211_scan_vattach(struct ieee80211vap *vap)
131 {
132 	struct ieee80211com *ic = vap->iv_ic;
133 	int m;
134 
135 	vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
136 	vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
137 	vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
138 
139 	vap->iv_roaming = IEEE80211_ROAMING_AUTO;
140 
141 	memset(vap->iv_roamparms, 0, sizeof(vap->iv_roamparms));
142 	for (m = IEEE80211_MODE_AUTO + 1; m < IEEE80211_MODE_MAX; m++) {
143 		if (isclr(ic->ic_modecaps, m))
144 			continue;
145 
146 		memcpy(&vap->iv_roamparms[m], &defroam[m], sizeof(defroam[m]));
147 	}
148 
149 	ic->ic_scan_methods->sc_vattach(vap);
150 }
151 
152 void
153 ieee80211_scan_vdetach(struct ieee80211vap *vap)
154 {
155 	struct ieee80211com *ic = vap->iv_ic;
156 	struct ieee80211_scan_state *ss;
157 
158 	IEEE80211_LOCK(ic);
159 	ss = ic->ic_scan;
160 
161 	ic->ic_scan_methods->sc_vdetach(vap);
162 
163 	if (ss != NULL && ss->ss_vap == vap) {
164 		if (ss->ss_ops != NULL) {
165 			ss->ss_ops->scan_detach(ss);
166 			ss->ss_ops = NULL;
167 		}
168 		ss->ss_vap = NULL;
169 	}
170 	IEEE80211_UNLOCK(ic);
171 }
172 
173 /*
174  * Simple-minded scanner module support.
175  */
176 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
177 	"wlan_scan_sta",	/* IEEE80211_M_IBSS */
178 	"wlan_scan_sta",	/* IEEE80211_M_STA */
179 	"wlan_scan_wds",	/* IEEE80211_M_WDS */
180 	"wlan_scan_sta",	/* IEEE80211_M_AHDEMO */
181 	"wlan_scan_ap",		/* IEEE80211_M_HOSTAP */
182 	"wlan_scan_monitor",	/* IEEE80211_M_MONITOR */
183 	"wlan_scan_sta",	/* IEEE80211_M_MBSS */
184 };
185 static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
186 
187 const struct ieee80211_scanner *
188 ieee80211_scanner_get(enum ieee80211_opmode mode)
189 {
190 	if (mode >= IEEE80211_OPMODE_MAX)
191 		return NULL;
192 	if (scanners[mode] == NULL)
193 		ieee80211_load_module(scan_modnames[mode]);
194 	return scanners[mode];
195 }
196 
197 void
198 ieee80211_scanner_register(enum ieee80211_opmode mode,
199 	const struct ieee80211_scanner *scan)
200 {
201 	if (mode >= IEEE80211_OPMODE_MAX)
202 		return;
203 	scanners[mode] = scan;
204 }
205 
206 void
207 ieee80211_scanner_unregister(enum ieee80211_opmode mode,
208 	const struct ieee80211_scanner *scan)
209 {
210 	if (mode >= IEEE80211_OPMODE_MAX)
211 		return;
212 	if (scanners[mode] == scan)
213 		scanners[mode] = NULL;
214 }
215 
216 void
217 ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
218 {
219 	int m;
220 
221 	for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
222 		if (scanners[m] == scan)
223 			scanners[m] = NULL;
224 }
225 
226 /*
227  * Update common scanner state to reflect the current
228  * operating mode.  This is called when the state machine
229  * is transitioned to RUN state w/o scanning--e.g. when
230  * operating in monitor mode.  The purpose of this is to
231  * ensure later callbacks find ss_ops set to properly
232  * reflect current operating mode.
233  */
234 void
235 ieee80211_scan_update_locked(struct ieee80211vap *vap,
236 	const struct ieee80211_scanner *scan)
237 {
238 	struct ieee80211com *ic = vap->iv_ic;
239 	struct ieee80211_scan_state *ss = ic->ic_scan;
240 
241 	IEEE80211_LOCK_ASSERT(ic);
242 
243 #ifdef IEEE80211_DEBUG
244 	if (ss->ss_vap != vap || ss->ss_ops != scan) {
245 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
246 		    "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
247 		    __func__,
248 		    ss->ss_vap != NULL ?
249 			ss->ss_vap->iv_ifp->if_xname : "none",
250 		    ss->ss_vap != NULL ?
251 			ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
252 		    vap->iv_ifp->if_xname,
253 		    ieee80211_opmode_name[vap->iv_opmode]);
254 	}
255 #endif
256 	ss->ss_vap = vap;
257 	if (ss->ss_ops != scan) {
258 		/*
259 		 * Switch scanners; detach old, attach new.  Special
260 		 * case where a single scan module implements multiple
261 		 * policies by using different scan ops but a common
262 		 * core.  We assume if the old and new attach methods
263 		 * are identical then it's ok to just change ss_ops
264 		 * and not flush the internal state of the module.
265 		 */
266 		if (scan == NULL || ss->ss_ops == NULL ||
267 		    ss->ss_ops->scan_attach != scan->scan_attach) {
268 			if (ss->ss_ops != NULL)
269 				ss->ss_ops->scan_detach(ss);
270 			if (scan != NULL && !scan->scan_attach(ss)) {
271 				/* XXX attach failure */
272 				/* XXX stat+msg */
273 				scan = NULL;
274 			}
275 		}
276 		ss->ss_ops = scan;
277 	}
278 }
279 
280 void
281 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
282 {
283 	struct ieee80211com *ic = ss->ss_ic;
284 	const char *sep;
285 	int i;
286 
287 	sep = "";
288 	for (i = ss->ss_next; i < ss->ss_last; i++) {
289 		const struct ieee80211_channel *c = ss->ss_chans[i];
290 
291 		printf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
292 		    ieee80211_channel_type_char(c));
293 		sep = ", ";
294 	}
295 }
296 
297 #ifdef IEEE80211_DEBUG
298 void
299 ieee80211_scan_dump(struct ieee80211_scan_state *ss)
300 {
301 	struct ieee80211vap *vap = ss->ss_vap;
302 
303 	if_printf(vap->iv_ifp, "scan set ");
304 	ieee80211_scan_dump_channels(ss);
305 	printf(" dwell min %ums max %ums\n",
306 	    ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
307 }
308 #endif /* IEEE80211_DEBUG */
309 
310 void
311 ieee80211_scan_copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
312 	int nssid, const struct ieee80211_scan_ssid ssids[])
313 {
314 	if (nssid > IEEE80211_SCAN_MAX_SSID) {
315 		/* XXX printf */
316 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
317 		    "%s: too many ssid %d, ignoring all of them\n",
318 		    __func__, nssid);
319 		return;
320 	}
321 	memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
322 	ss->ss_nssid = nssid;
323 }
324 
325 /*
326  * Start a scan unless one is already going.
327  */
328 int
329 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
330 	u_int duration, u_int mindwell, u_int maxdwell,
331 	u_int nssid, const struct ieee80211_scan_ssid ssids[])
332 {
333 	const struct ieee80211_scanner *scan;
334 	struct ieee80211com *ic = vap->iv_ic;
335 
336 	scan = ieee80211_scanner_get(vap->iv_opmode);
337 	if (scan == NULL) {
338 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
339 		    "%s: no scanner support for %s mode\n",
340 		    __func__, ieee80211_opmode_name[vap->iv_opmode]);
341 		/* XXX stat */
342 		return 0;
343 	}
344 
345 	return ic->ic_scan_methods->sc_start_scan(scan, vap, flags, duration,
346 	    mindwell, maxdwell, nssid, ssids);
347 }
348 
349 /*
350  * Check the scan cache for an ap/channel to use; if that
351  * fails then kick off a new scan.
352  */
353 int
354 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
355 	u_int duration, u_int mindwell, u_int maxdwell,
356 	u_int nssid, const struct ieee80211_scan_ssid ssids[])
357 {
358 	struct ieee80211com *ic = vap->iv_ic;
359 	struct ieee80211_scan_state *ss = ic->ic_scan;
360 	const struct ieee80211_scanner *scan;
361 	int result;
362 
363 	scan = ieee80211_scanner_get(vap->iv_opmode);
364 	if (scan == NULL) {
365 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
366 		    "%s: no scanner support for %s mode\n",
367 		    __func__, vap->iv_opmode);
368 		/* XXX stat */
369 		return 0;
370 	}
371 
372 	/*
373 	 * Check if there's a list of scan candidates already.
374 	 * XXX want more than the ap we're currently associated with
375 	 */
376 
377 	IEEE80211_LOCK(ic);
378 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
379 	    "%s: %s scan, %s%s%s%s%s\n"
380 	    , __func__
381 	    , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
382 	    , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
383 	    , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
384 	    , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
385 	    , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
386 	    , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
387 	);
388 
389 	if (ss->ss_ops != scan) {
390 		/* XXX re-use cache contents? e.g. adhoc<->sta */
391 		flags |= IEEE80211_SCAN_FLUSH;
392 	}
393 
394 	/*
395 	 * XXX TODO: separate things out a bit better.
396 	 */
397 	ieee80211_scan_update_locked(vap, scan);
398 
399 	result = ic->ic_scan_methods->sc_check_scan(scan, vap, flags, duration,
400 	    mindwell, maxdwell, nssid, ssids);
401 
402 	IEEE80211_UNLOCK(ic);
403 
404 	return (result);
405 }
406 
407 /*
408  * Check the scan cache for an ap/channel to use; if that fails
409  * then kick off a scan using the current settings.
410  */
411 int
412 ieee80211_check_scan_current(struct ieee80211vap *vap)
413 {
414 	return ieee80211_check_scan(vap,
415 	    IEEE80211_SCAN_ACTIVE,
416 	    IEEE80211_SCAN_FOREVER, 0, 0,
417 	    vap->iv_des_nssid, vap->iv_des_ssid);
418 }
419 
420 /*
421  * Restart a previous scan.  If the previous scan completed
422  * then we start again using the existing channel list.
423  */
424 int
425 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
426 {
427 	struct ieee80211com *ic = vap->iv_ic;
428 	const struct ieee80211_scanner *scan;
429 
430 	// IEEE80211_UNLOCK_ASSERT(sc);
431 
432 	scan = ieee80211_scanner_get(vap->iv_opmode);
433 	if (scan == NULL) {
434 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
435 		    "%s: no scanner support for %s mode\n",
436 		    __func__, vap->iv_opmode);
437 		/* XXX stat */
438 		return 0;
439 	}
440 
441 	/*
442 	 * XXX TODO: pull apart the bgscan logic into whatever
443 	 * belongs here and whatever belongs in the software
444 	 * scanner.
445 	 */
446 	return (ic->ic_scan_methods->sc_bg_scan(scan, vap, flags));
447 }
448 
449 /*
450  * Cancel any scan currently going on for the specified vap.
451  */
452 void
453 ieee80211_cancel_scan(struct ieee80211vap *vap)
454 {
455 	struct ieee80211com *ic = vap->iv_ic;
456 
457 	ic->ic_scan_methods->sc_cancel_scan(vap);
458 }
459 
460 /*
461  * Cancel any scan currently going on.
462  *
463  * This is called during normal 802.11 data path to cancel
464  * a scan so a newly arrived normal data packet can be sent.
465  */
466 void
467 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
468 {
469 	struct ieee80211com *ic = vap->iv_ic;
470 
471 	ic->ic_scan_methods->sc_cancel_anyscan(vap);
472 }
473 
474 /*
475  * Manually switch to the next channel in the channel list.
476  * Provided for drivers that manage scanning themselves
477  * (e.g. for firmware-based devices).
478  */
479 void
480 ieee80211_scan_next(struct ieee80211vap *vap)
481 {
482 	struct ieee80211com *ic = vap->iv_ic;
483 
484 	ic->ic_scan_methods->sc_scan_next(vap);
485 }
486 
487 /*
488  * Manually stop a scan that is currently running.
489  * Provided for drivers that are not able to scan single channels
490  * (e.g. for firmware-based devices).
491  */
492 void
493 ieee80211_scan_done(struct ieee80211vap *vap)
494 {
495 	struct ieee80211com *ic = vap->iv_ic;
496 	struct ieee80211_scan_state *ss;
497 
498 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
499 
500 	IEEE80211_LOCK(ic);
501 	ss = ic->ic_scan;
502 	ss->ss_next = ss->ss_last; /* all channels are complete */
503 
504 	ic->ic_scan_methods->sc_scan_done(vap);
505 
506 	IEEE80211_UNLOCK(ic);
507 }
508 
509 /*
510  * Probe the current channel, if allowed, while scanning.
511  * If the channel is not marked passive-only then send
512  * a probe request immediately.  Otherwise mark state and
513  * listen for beacons on the channel; if we receive something
514  * then we'll transmit a probe request.
515  */
516 void
517 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
518 {
519 	struct ieee80211com *ic = vap->iv_ic;
520 
521 	if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
522 		ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
523 		return;
524 	}
525 
526 	ic->ic_scan_methods->sc_scan_probe_curchan(vap, force);
527 }
528 
529 #ifdef IEEE80211_DEBUG
530 static void
531 dump_country(const uint8_t *ie)
532 {
533 	const struct ieee80211_country_ie *cie =
534 	   (const struct ieee80211_country_ie *) ie;
535 	int i, nbands, schan, nchan;
536 
537 	if (cie->len < 3) {
538 		printf(" <bogus country ie, len %d>", cie->len);
539 		return;
540 	}
541 	printf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
542 	nbands = (cie->len - 3) / sizeof(cie->band[0]);
543 	for (i = 0; i < nbands; i++) {
544 		schan = cie->band[i].schan;
545 		nchan = cie->band[i].nchan;
546 		if (nchan != 1)
547 			printf(" %u-%u,%u", schan, schan + nchan-1,
548 			    cie->band[i].maxtxpwr);
549 		else
550 			printf(" %u,%u", schan, cie->band[i].maxtxpwr);
551 	}
552 	printf("]");
553 }
554 
555 void
556 ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
557 	const uint8_t mac[IEEE80211_ADDR_LEN],
558 	const struct ieee80211_scanparams *sp, int rssi)
559 {
560 
561 	printf("[%s] %s%s on chan %u (bss chan %u) ",
562 	    ether_sprintf(mac), isnew ? "new " : "",
563 	    ieee80211_mgt_subtype_name(subtype), sp->chan, sp->bchan);
564 	ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
565 	printf(" rssi %d\n", rssi);
566 
567 	if (isnew) {
568 		printf("[%s] caps 0x%x bintval %u erp 0x%x",
569 			ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
570 		if (sp->country != NULL)
571 			dump_country(sp->country);
572 		printf("\n");
573 	}
574 }
575 #endif /* IEEE80211_DEBUG */
576 
577 /*
578  * Process a beacon or probe response frame.
579  */
580 void
581 ieee80211_add_scan(struct ieee80211vap *vap,
582 	struct ieee80211_channel *curchan,
583 	const struct ieee80211_scanparams *sp,
584 	const struct ieee80211_frame *wh,
585 	int subtype, int rssi, int noise)
586 {
587 	struct ieee80211com *ic = vap->iv_ic;
588 
589 	return (ic->ic_scan_methods->sc_add_scan(vap, curchan, sp, wh, subtype,
590 	    rssi, noise));
591 }
592 
593 /*
594  * Timeout/age scan cache entries; called from sta timeout
595  * timer (XXX should be self-contained).
596  */
597 void
598 ieee80211_scan_timeout(struct ieee80211com *ic)
599 {
600 	struct ieee80211_scan_state *ss = ic->ic_scan;
601 
602 	if (ss->ss_ops != NULL)
603 		ss->ss_ops->scan_age(ss);
604 }
605 
606 /*
607  * Mark a scan cache entry after a successful associate.
608  */
609 void
610 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
611 {
612 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
613 
614 	if (ss->ss_ops != NULL) {
615 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
616 			mac, "%s",  __func__);
617 		ss->ss_ops->scan_assoc_success(ss, mac);
618 	}
619 }
620 
621 /*
622  * Demerit a scan cache entry after failing to associate.
623  */
624 void
625 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
626 	const uint8_t mac[], int reason)
627 {
628 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
629 
630 	if (ss->ss_ops != NULL) {
631 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
632 			"%s: reason %u", __func__, reason);
633 		ss->ss_ops->scan_assoc_fail(ss, mac, reason);
634 	}
635 }
636 
637 /*
638  * Iterate over the contents of the scan cache.
639  */
640 void
641 ieee80211_scan_iterate(struct ieee80211vap *vap,
642 	ieee80211_scan_iter_func *f, void *arg)
643 {
644 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
645 
646 	if (ss->ss_ops != NULL)
647 		ss->ss_ops->scan_iterate(ss, f, arg);
648 }
649 
650 /*
651  * Flush the contents of the scan cache.
652  */
653 void
654 ieee80211_scan_flush(struct ieee80211vap *vap)
655 {
656 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
657 
658 	if (ss->ss_ops != NULL && ss->ss_vap == vap) {
659 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
660 		ss->ss_ops->scan_flush(ss);
661 	}
662 }
663 
664 /*
665  * Check the scan cache for an ap/channel to use; if that
666  * fails then kick off a new scan.
667  */
668 struct ieee80211_channel *
669 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
670 {
671 	struct ieee80211_scan_state *ss = ic->ic_scan;
672 
673 	IEEE80211_LOCK_ASSERT(ic);
674 
675 	if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
676 		/* XXX printf? */
677 		return NULL;
678 	}
679 	if (ss->ss_ops->scan_pickchan == NULL) {
680 		IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
681 		    "%s: scan module does not support picking a channel, "
682 		    "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
683 		return NULL;
684 	}
685 	return ss->ss_ops->scan_pickchan(ss, flags);
686 }
687