xref: /freebsd/sys/net80211/ieee80211_scan.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
1 /*-
2  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 /*
30  * IEEE 802.11 scanning support.
31  */
32 #include "opt_wlan.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/proc.h>
37 #include <sys/kernel.h>
38 #include <sys/malloc.h>
39 #include <sys/condvar.h>
40 
41 #include <sys/socket.h>
42 
43 #include <net/if.h>
44 #include <net/if_var.h>
45 #include <net/if_media.h>
46 #include <net/ethernet.h>
47 
48 #include <net80211/ieee80211_var.h>
49 
50 /* XXX until it's implemented as attach ops */
51 #include <net80211/ieee80211_scan_sw.h>
52 
53 #include <net/bpf.h>
54 
55 /*
56  * Roaming-related defaults.  RSSI thresholds are as returned by the
57  * driver (.5dBm).  Transmit rate thresholds are IEEE rate codes (i.e
58  * .5M units) or MCS.
59  */
60 /* rssi thresholds */
61 #define	ROAM_RSSI_11A_DEFAULT		14	/* 11a bss */
62 #define	ROAM_RSSI_11B_DEFAULT		14	/* 11b bss */
63 #define	ROAM_RSSI_11BONLY_DEFAULT	14	/* 11b-only bss */
64 /* transmit rate thresholds */
65 #define	ROAM_RATE_11A_DEFAULT		2*12	/* 11a bss */
66 #define	ROAM_RATE_11B_DEFAULT		2*5	/* 11b bss */
67 #define	ROAM_RATE_11BONLY_DEFAULT	2*1	/* 11b-only bss */
68 #define	ROAM_RATE_HALF_DEFAULT		2*6	/* half-width 11a/g bss */
69 #define	ROAM_RATE_QUARTER_DEFAULT	2*3	/* quarter-width 11a/g bss */
70 #define	ROAM_MCS_11N_DEFAULT		(1 | IEEE80211_RATE_MCS) /* 11n bss */
71 
72 void
73 ieee80211_scan_attach(struct ieee80211com *ic)
74 {
75 	/*
76 	 * If there's no scan method pointer, attach the
77 	 * swscan set as a default.
78 	 */
79 	if (ic->ic_scan_methods == NULL)
80 		ieee80211_swscan_attach(ic);
81 	else
82 		ic->ic_scan_methods->sc_attach(ic);
83 }
84 
85 void
86 ieee80211_scan_detach(struct ieee80211com *ic)
87 {
88 
89 	/*
90 	 * Ideally we'd do the ss_ops detach call here;
91 	 * but then sc_detach() would need to be split in two.
92 	 *
93 	 * I'll do that later.
94 	 */
95 	ic->ic_scan_methods->sc_detach(ic);
96 }
97 
98 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
99 	[IEEE80211_MODE_11A]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
100 				    .rate = ROAM_RATE_11A_DEFAULT },
101 	[IEEE80211_MODE_11G]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
102 				    .rate = ROAM_RATE_11B_DEFAULT },
103 	[IEEE80211_MODE_11B]	= { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
104 				    .rate = ROAM_RATE_11BONLY_DEFAULT },
105 	[IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
106 				    .rate = ROAM_RATE_11A_DEFAULT },
107 	[IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
108 				    .rate = ROAM_RATE_11A_DEFAULT },
109 	[IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
110 				    .rate = ROAM_RATE_11A_DEFAULT },
111 	[IEEE80211_MODE_HALF]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
112 				    .rate = ROAM_RATE_HALF_DEFAULT },
113 	[IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
114 				    .rate = ROAM_RATE_QUARTER_DEFAULT },
115 	[IEEE80211_MODE_11NA]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
116 				    .rate = ROAM_MCS_11N_DEFAULT },
117 	[IEEE80211_MODE_11NG]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
118 				    .rate = ROAM_MCS_11N_DEFAULT },
119 };
120 
121 void
122 ieee80211_scan_vattach(struct ieee80211vap *vap)
123 {
124 	struct ieee80211com *ic = vap->iv_ic;
125 
126 	vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
127 	vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
128 	vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
129 
130 	vap->iv_roaming = IEEE80211_ROAMING_AUTO;
131 	memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
132 
133 	ic->ic_scan_methods->sc_vattach(vap);
134 }
135 
136 void
137 ieee80211_scan_vdetach(struct ieee80211vap *vap)
138 {
139 	struct ieee80211com *ic = vap->iv_ic;
140 	struct ieee80211_scan_state *ss;
141 
142 	IEEE80211_LOCK(ic);
143 	ss = ic->ic_scan;
144 
145 	ic->ic_scan_methods->sc_vdetach(vap);
146 
147 	if (ss != NULL && ss->ss_vap == vap) {
148 		if (ss->ss_ops != NULL) {
149 			ss->ss_ops->scan_detach(ss);
150 			ss->ss_ops = NULL;
151 		}
152 		ss->ss_vap = NULL;
153 	}
154 	IEEE80211_UNLOCK(ic);
155 }
156 
157 /*
158  * Simple-minded scanner module support.
159  */
160 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
161 	"wlan_scan_sta",	/* IEEE80211_M_IBSS */
162 	"wlan_scan_sta",	/* IEEE80211_M_STA */
163 	"wlan_scan_wds",	/* IEEE80211_M_WDS */
164 	"wlan_scan_sta",	/* IEEE80211_M_AHDEMO */
165 	"wlan_scan_ap",		/* IEEE80211_M_HOSTAP */
166 	"wlan_scan_monitor",	/* IEEE80211_M_MONITOR */
167 	"wlan_scan_sta",	/* IEEE80211_M_MBSS */
168 };
169 static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
170 
171 const struct ieee80211_scanner *
172 ieee80211_scanner_get(enum ieee80211_opmode mode)
173 {
174 	if (mode >= IEEE80211_OPMODE_MAX)
175 		return NULL;
176 	if (scanners[mode] == NULL)
177 		ieee80211_load_module(scan_modnames[mode]);
178 	return scanners[mode];
179 }
180 
181 void
182 ieee80211_scanner_register(enum ieee80211_opmode mode,
183 	const struct ieee80211_scanner *scan)
184 {
185 	if (mode >= IEEE80211_OPMODE_MAX)
186 		return;
187 	scanners[mode] = scan;
188 }
189 
190 void
191 ieee80211_scanner_unregister(enum ieee80211_opmode mode,
192 	const struct ieee80211_scanner *scan)
193 {
194 	if (mode >= IEEE80211_OPMODE_MAX)
195 		return;
196 	if (scanners[mode] == scan)
197 		scanners[mode] = NULL;
198 }
199 
200 void
201 ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
202 {
203 	int m;
204 
205 	for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
206 		if (scanners[m] == scan)
207 			scanners[m] = NULL;
208 }
209 
210 /*
211  * Update common scanner state to reflect the current
212  * operating mode.  This is called when the state machine
213  * is transitioned to RUN state w/o scanning--e.g. when
214  * operating in monitor mode.  The purpose of this is to
215  * ensure later callbacks find ss_ops set to properly
216  * reflect current operating mode.
217  */
218 void
219 ieee80211_scan_update_locked(struct ieee80211vap *vap,
220 	const struct ieee80211_scanner *scan)
221 {
222 	struct ieee80211com *ic = vap->iv_ic;
223 	struct ieee80211_scan_state *ss = ic->ic_scan;
224 
225 	IEEE80211_LOCK_ASSERT(ic);
226 
227 #ifdef IEEE80211_DEBUG
228 	if (ss->ss_vap != vap || ss->ss_ops != scan) {
229 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
230 		    "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
231 		    __func__,
232 		    ss->ss_vap != NULL ?
233 			ss->ss_vap->iv_ifp->if_xname : "none",
234 		    ss->ss_vap != NULL ?
235 			ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
236 		    vap->iv_ifp->if_xname,
237 		    ieee80211_opmode_name[vap->iv_opmode]);
238 	}
239 #endif
240 	ss->ss_vap = vap;
241 	if (ss->ss_ops != scan) {
242 		/*
243 		 * Switch scanners; detach old, attach new.  Special
244 		 * case where a single scan module implements multiple
245 		 * policies by using different scan ops but a common
246 		 * core.  We assume if the old and new attach methods
247 		 * are identical then it's ok to just change ss_ops
248 		 * and not flush the internal state of the module.
249 		 */
250 		if (scan == NULL || ss->ss_ops == NULL ||
251 		    ss->ss_ops->scan_attach != scan->scan_attach) {
252 			if (ss->ss_ops != NULL)
253 				ss->ss_ops->scan_detach(ss);
254 			if (scan != NULL && !scan->scan_attach(ss)) {
255 				/* XXX attach failure */
256 				/* XXX stat+msg */
257 				scan = NULL;
258 			}
259 		}
260 		ss->ss_ops = scan;
261 	}
262 }
263 
264 void
265 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
266 {
267 	struct ieee80211com *ic = ss->ss_ic;
268 	const char *sep;
269 	int i;
270 
271 	sep = "";
272 	for (i = ss->ss_next; i < ss->ss_last; i++) {
273 		const struct ieee80211_channel *c = ss->ss_chans[i];
274 
275 		printf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
276 		    ieee80211_channel_type_char(c));
277 		sep = ", ";
278 	}
279 }
280 
281 #ifdef IEEE80211_DEBUG
282 void
283 ieee80211_scan_dump(struct ieee80211_scan_state *ss)
284 {
285 	struct ieee80211vap *vap = ss->ss_vap;
286 
287 	if_printf(vap->iv_ifp, "scan set ");
288 	ieee80211_scan_dump_channels(ss);
289 	printf(" dwell min %lums max %lums\n",
290 	    ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
291 }
292 #endif /* IEEE80211_DEBUG */
293 
294 void
295 ieee80211_scan_copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
296 	int nssid, const struct ieee80211_scan_ssid ssids[])
297 {
298 	if (nssid > IEEE80211_SCAN_MAX_SSID) {
299 		/* XXX printf */
300 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
301 		    "%s: too many ssid %d, ignoring all of them\n",
302 		    __func__, nssid);
303 		return;
304 	}
305 	memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
306 	ss->ss_nssid = nssid;
307 }
308 
309 /*
310  * Start a scan unless one is already going.
311  */
312 int
313 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
314 	u_int duration, u_int mindwell, u_int maxdwell,
315 	u_int nssid, const struct ieee80211_scan_ssid ssids[])
316 {
317 	const struct ieee80211_scanner *scan;
318 	struct ieee80211com *ic = vap->iv_ic;
319 
320 	scan = ieee80211_scanner_get(vap->iv_opmode);
321 	if (scan == NULL) {
322 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
323 		    "%s: no scanner support for %s mode\n",
324 		    __func__, ieee80211_opmode_name[vap->iv_opmode]);
325 		/* XXX stat */
326 		return 0;
327 	}
328 
329 	return ic->ic_scan_methods->sc_start_scan(scan, vap, flags, duration,
330 	    mindwell, maxdwell, nssid, ssids);
331 }
332 
333 /*
334  * Check the scan cache for an ap/channel to use; if that
335  * fails then kick off a new scan.
336  */
337 int
338 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
339 	u_int duration, u_int mindwell, u_int maxdwell,
340 	u_int nssid, const struct ieee80211_scan_ssid ssids[])
341 {
342 	struct ieee80211com *ic = vap->iv_ic;
343 	struct ieee80211_scan_state *ss = ic->ic_scan;
344 	const struct ieee80211_scanner *scan;
345 	int result;
346 
347 	scan = ieee80211_scanner_get(vap->iv_opmode);
348 	if (scan == NULL) {
349 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
350 		    "%s: no scanner support for %s mode\n",
351 		    __func__, vap->iv_opmode);
352 		/* XXX stat */
353 		return 0;
354 	}
355 
356 	/*
357 	 * Check if there's a list of scan candidates already.
358 	 * XXX want more than the ap we're currently associated with
359 	 */
360 
361 	IEEE80211_LOCK(ic);
362 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
363 	    "%s: %s scan, %s%s%s%s%s\n"
364 	    , __func__
365 	    , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
366 	    , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
367 	    , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
368 	    , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
369 	    , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
370 	    , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
371 	);
372 
373 	if (ss->ss_ops != scan) {
374 		/* XXX re-use cache contents? e.g. adhoc<->sta */
375 		flags |= IEEE80211_SCAN_FLUSH;
376 	}
377 
378 	/*
379 	 * XXX TODO: separate things out a bit better.
380 	 */
381 	ieee80211_scan_update_locked(vap, scan);
382 
383 	result = ic->ic_scan_methods->sc_check_scan(scan, vap, flags, duration,
384 	    mindwell, maxdwell, nssid, ssids);
385 
386 	IEEE80211_UNLOCK(ic);
387 
388 	return (result);
389 }
390 
391 /*
392  * Check the scan cache for an ap/channel to use; if that fails
393  * then kick off a scan using the current settings.
394  */
395 int
396 ieee80211_check_scan_current(struct ieee80211vap *vap)
397 {
398 	return ieee80211_check_scan(vap,
399 	    IEEE80211_SCAN_ACTIVE,
400 	    IEEE80211_SCAN_FOREVER, 0, 0,
401 	    vap->iv_des_nssid, vap->iv_des_ssid);
402 }
403 
404 /*
405  * Restart a previous scan.  If the previous scan completed
406  * then we start again using the existing channel list.
407  */
408 int
409 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
410 {
411 	struct ieee80211com *ic = vap->iv_ic;
412 	const struct ieee80211_scanner *scan;
413 
414 	// IEEE80211_UNLOCK_ASSERT(sc);
415 
416 	scan = ieee80211_scanner_get(vap->iv_opmode);
417 	if (scan == NULL) {
418 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
419 		    "%s: no scanner support for %s mode\n",
420 		    __func__, vap->iv_opmode);
421 		/* XXX stat */
422 		return 0;
423 	}
424 
425 	/*
426 	 * XXX TODO: pull apart the bgscan logic into whatever
427 	 * belongs here and whatever belongs in the software
428 	 * scanner.
429 	 */
430 	return (ic->ic_scan_methods->sc_bg_scan(scan, vap, flags));
431 }
432 
433 /*
434  * Cancel any scan currently going on for the specified vap.
435  */
436 void
437 ieee80211_cancel_scan(struct ieee80211vap *vap)
438 {
439 	struct ieee80211com *ic = vap->iv_ic;
440 
441 	ic->ic_scan_methods->sc_cancel_scan(vap);
442 }
443 
444 /*
445  * Cancel any scan currently going on.
446  *
447  * This is called during normal 802.11 data path to cancel
448  * a scan so a newly arrived normal data packet can be sent.
449  */
450 void
451 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
452 {
453 	struct ieee80211com *ic = vap->iv_ic;
454 
455 	ic->ic_scan_methods->sc_cancel_anyscan(vap);
456 }
457 
458 /*
459  * Manually switch to the next channel in the channel list.
460  * Provided for drivers that manage scanning themselves
461  * (e.g. for firmware-based devices).
462  */
463 void
464 ieee80211_scan_next(struct ieee80211vap *vap)
465 {
466 	struct ieee80211com *ic = vap->iv_ic;
467 
468 	ic->ic_scan_methods->sc_scan_next(vap);
469 }
470 
471 /*
472  * Manually stop a scan that is currently running.
473  * Provided for drivers that are not able to scan single channels
474  * (e.g. for firmware-based devices).
475  */
476 void
477 ieee80211_scan_done(struct ieee80211vap *vap)
478 {
479 	struct ieee80211com *ic = vap->iv_ic;
480 	struct ieee80211_scan_state *ss;
481 
482 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
483 
484 	IEEE80211_LOCK(ic);
485 	ss = ic->ic_scan;
486 	ss->ss_next = ss->ss_last; /* all channels are complete */
487 
488 	ic->ic_scan_methods->sc_scan_done(vap);
489 
490 	IEEE80211_UNLOCK(ic);
491 }
492 
493 /*
494  * Probe the current channel, if allowed, while scanning.
495  * If the channel is not marked passive-only then send
496  * a probe request immediately.  Otherwise mark state and
497  * listen for beacons on the channel; if we receive something
498  * then we'll transmit a probe request.
499  */
500 void
501 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
502 {
503 	struct ieee80211com *ic = vap->iv_ic;
504 
505 	if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
506 		ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
507 		return;
508 	}
509 
510 	ic->ic_scan_methods->sc_scan_probe_curchan(vap, force);
511 }
512 
513 #ifdef IEEE80211_DEBUG
514 static void
515 dump_country(const uint8_t *ie)
516 {
517 	const struct ieee80211_country_ie *cie =
518 	   (const struct ieee80211_country_ie *) ie;
519 	int i, nbands, schan, nchan;
520 
521 	if (cie->len < 3) {
522 		printf(" <bogus country ie, len %d>", cie->len);
523 		return;
524 	}
525 	printf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
526 	nbands = (cie->len - 3) / sizeof(cie->band[0]);
527 	for (i = 0; i < nbands; i++) {
528 		schan = cie->band[i].schan;
529 		nchan = cie->band[i].nchan;
530 		if (nchan != 1)
531 			printf(" %u-%u,%u", schan, schan + nchan-1,
532 			    cie->band[i].maxtxpwr);
533 		else
534 			printf(" %u,%u", schan, cie->band[i].maxtxpwr);
535 	}
536 	printf("]");
537 }
538 
539 void
540 ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
541 	const uint8_t mac[IEEE80211_ADDR_LEN],
542 	const struct ieee80211_scanparams *sp, int rssi)
543 {
544 
545 	printf("[%s] %s%s on chan %u (bss chan %u) ",
546 	    ether_sprintf(mac), isnew ? "new " : "",
547 	    ieee80211_mgt_subtype_name(subtype), sp->chan, sp->bchan);
548 	ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
549 	printf(" rssi %d\n", rssi);
550 
551 	if (isnew) {
552 		printf("[%s] caps 0x%x bintval %u erp 0x%x",
553 			ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
554 		if (sp->country != NULL)
555 			dump_country(sp->country);
556 		printf("\n");
557 	}
558 }
559 #endif /* IEEE80211_DEBUG */
560 
561 /*
562  * Process a beacon or probe response frame.
563  */
564 void
565 ieee80211_add_scan(struct ieee80211vap *vap,
566 	struct ieee80211_channel *curchan,
567 	const struct ieee80211_scanparams *sp,
568 	const struct ieee80211_frame *wh,
569 	int subtype, int rssi, int noise)
570 {
571 	struct ieee80211com *ic = vap->iv_ic;
572 
573 	return (ic->ic_scan_methods->sc_add_scan(vap, curchan, sp, wh, subtype,
574 	    rssi, noise));
575 }
576 
577 /*
578  * Timeout/age scan cache entries; called from sta timeout
579  * timer (XXX should be self-contained).
580  */
581 void
582 ieee80211_scan_timeout(struct ieee80211com *ic)
583 {
584 	struct ieee80211_scan_state *ss = ic->ic_scan;
585 
586 	if (ss->ss_ops != NULL)
587 		ss->ss_ops->scan_age(ss);
588 }
589 
590 /*
591  * Mark a scan cache entry after a successful associate.
592  */
593 void
594 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
595 {
596 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
597 
598 	if (ss->ss_ops != NULL) {
599 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
600 			mac, "%s",  __func__);
601 		ss->ss_ops->scan_assoc_success(ss, mac);
602 	}
603 }
604 
605 /*
606  * Demerit a scan cache entry after failing to associate.
607  */
608 void
609 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
610 	const uint8_t mac[], int reason)
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, mac,
616 			"%s: reason %u", __func__, reason);
617 		ss->ss_ops->scan_assoc_fail(ss, mac, reason);
618 	}
619 }
620 
621 /*
622  * Iterate over the contents of the scan cache.
623  */
624 void
625 ieee80211_scan_iterate(struct ieee80211vap *vap,
626 	ieee80211_scan_iter_func *f, void *arg)
627 {
628 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
629 
630 	if (ss->ss_ops != NULL)
631 		ss->ss_ops->scan_iterate(ss, f, arg);
632 }
633 
634 /*
635  * Flush the contents of the scan cache.
636  */
637 void
638 ieee80211_scan_flush(struct ieee80211vap *vap)
639 {
640 	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
641 
642 	if (ss->ss_ops != NULL && ss->ss_vap == vap) {
643 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
644 		ss->ss_ops->scan_flush(ss);
645 	}
646 }
647 
648 /*
649  * Check the scan cache for an ap/channel to use; if that
650  * fails then kick off a new scan.
651  */
652 struct ieee80211_channel *
653 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
654 {
655 	struct ieee80211_scan_state *ss = ic->ic_scan;
656 
657 	IEEE80211_LOCK_ASSERT(ic);
658 
659 	if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
660 		/* XXX printf? */
661 		return NULL;
662 	}
663 	if (ss->ss_ops->scan_pickchan == NULL) {
664 		IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
665 		    "%s: scan module does not support picking a channel, "
666 		    "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
667 		return NULL;
668 	}
669 	return ss->ss_ops->scan_pickchan(ss, flags);
670 }
671