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: releng/12.0/sys/net80211/ieee80211_scan.c 326272 2017-11-27 15:23:17Z pfg $");
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
75void
76ieee80211_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
88void
89ieee80211_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
101static 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
129void
130ieee80211_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
152void
153ieee80211_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 */
176static 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};
185static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
186
187const struct ieee80211_scanner *
188ieee80211_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
197void
198ieee80211_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
206void
207ieee80211_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
216void
217ieee80211_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 */
234void
235ieee80211_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
280void
281ieee80211_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
298void
299ieee80211_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
310void
311ieee80211_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 */
328int
329ieee80211_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 */
353int
354ieee80211_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#ifdef __HAIKU__
395	/* We never want to join if not explicitly looking for an SSID */
396	if (nssid == 0 && (flags & IEEE80211_SCAN_NOJOIN) == 0) {
397		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
398			"%s: setting nojoin due to no configured ssid\n", __func__);
399		flags |= IEEE80211_SCAN_NOJOIN;
400	}
401#endif
402
403	/*
404	 * XXX TODO: separate things out a bit better.
405	 */
406	ieee80211_scan_update_locked(vap, scan);
407
408	result = ic->ic_scan_methods->sc_check_scan(scan, vap, flags, duration,
409	    mindwell, maxdwell, nssid, ssids);
410
411	IEEE80211_UNLOCK(ic);
412
413	return (result);
414}
415
416/*
417 * Check the scan cache for an ap/channel to use; if that fails
418 * then kick off a scan using the current settings.
419 */
420int
421ieee80211_check_scan_current(struct ieee80211vap *vap)
422{
423	return ieee80211_check_scan(vap,
424	    IEEE80211_SCAN_ACTIVE,
425	    IEEE80211_SCAN_FOREVER, 0, 0,
426	    vap->iv_des_nssid, vap->iv_des_ssid);
427}
428
429/*
430 * Restart a previous scan.  If the previous scan completed
431 * then we start again using the existing channel list.
432 */
433int
434ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
435{
436	struct ieee80211com *ic = vap->iv_ic;
437	const struct ieee80211_scanner *scan;
438
439	// IEEE80211_UNLOCK_ASSERT(sc);
440
441	scan = ieee80211_scanner_get(vap->iv_opmode);
442	if (scan == NULL) {
443		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
444		    "%s: no scanner support for %s mode\n",
445		    __func__, vap->iv_opmode);
446		/* XXX stat */
447		return 0;
448	}
449
450	/*
451	 * XXX TODO: pull apart the bgscan logic into whatever
452	 * belongs here and whatever belongs in the software
453	 * scanner.
454	 */
455	return (ic->ic_scan_methods->sc_bg_scan(scan, vap, flags));
456}
457
458/*
459 * Cancel any scan currently going on for the specified vap.
460 */
461void
462ieee80211_cancel_scan(struct ieee80211vap *vap)
463{
464	struct ieee80211com *ic = vap->iv_ic;
465
466	ic->ic_scan_methods->sc_cancel_scan(vap);
467}
468
469/*
470 * Cancel any scan currently going on.
471 *
472 * This is called during normal 802.11 data path to cancel
473 * a scan so a newly arrived normal data packet can be sent.
474 */
475void
476ieee80211_cancel_anyscan(struct ieee80211vap *vap)
477{
478	struct ieee80211com *ic = vap->iv_ic;
479
480	ic->ic_scan_methods->sc_cancel_anyscan(vap);
481}
482
483/*
484 * Manually switch to the next channel in the channel list.
485 * Provided for drivers that manage scanning themselves
486 * (e.g. for firmware-based devices).
487 */
488void
489ieee80211_scan_next(struct ieee80211vap *vap)
490{
491	struct ieee80211com *ic = vap->iv_ic;
492
493	ic->ic_scan_methods->sc_scan_next(vap);
494}
495
496/*
497 * Manually stop a scan that is currently running.
498 * Provided for drivers that are not able to scan single channels
499 * (e.g. for firmware-based devices).
500 */
501void
502ieee80211_scan_done(struct ieee80211vap *vap)
503{
504	struct ieee80211com *ic = vap->iv_ic;
505	struct ieee80211_scan_state *ss;
506
507	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
508
509	IEEE80211_LOCK(ic);
510	ss = ic->ic_scan;
511	ss->ss_next = ss->ss_last; /* all channels are complete */
512
513	ic->ic_scan_methods->sc_scan_done(vap);
514
515	IEEE80211_UNLOCK(ic);
516}
517
518/*
519 * Probe the current channel, if allowed, while scanning.
520 * If the channel is not marked passive-only then send
521 * a probe request immediately.  Otherwise mark state and
522 * listen for beacons on the channel; if we receive something
523 * then we'll transmit a probe request.
524 */
525void
526ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
527{
528	struct ieee80211com *ic = vap->iv_ic;
529
530	if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
531		ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
532		return;
533	}
534
535	ic->ic_scan_methods->sc_scan_probe_curchan(vap, force);
536}
537
538#ifdef IEEE80211_DEBUG
539static void
540dump_country(const uint8_t *ie)
541{
542	const struct ieee80211_country_ie *cie =
543	   (const struct ieee80211_country_ie *) ie;
544	int i, nbands, schan, nchan;
545
546	if (cie->len < 3) {
547		printf(" <bogus country ie, len %d>", cie->len);
548		return;
549	}
550	printf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
551	nbands = (cie->len - 3) / sizeof(cie->band[0]);
552	for (i = 0; i < nbands; i++) {
553		schan = cie->band[i].schan;
554		nchan = cie->band[i].nchan;
555		if (nchan != 1)
556			printf(" %u-%u,%u", schan, schan + nchan-1,
557			    cie->band[i].maxtxpwr);
558		else
559			printf(" %u,%u", schan, cie->band[i].maxtxpwr);
560	}
561	printf("]");
562}
563
564void
565ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
566	const uint8_t mac[IEEE80211_ADDR_LEN],
567	const struct ieee80211_scanparams *sp, int rssi)
568{
569
570	printf("[%s] %s%s on chan %u (bss chan %u) ",
571	    ether_sprintf(mac), isnew ? "new " : "",
572	    ieee80211_mgt_subtype_name(subtype), sp->chan, sp->bchan);
573	ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
574	printf(" rssi %d\n", rssi);
575
576	if (isnew) {
577		printf("[%s] caps 0x%x bintval %u erp 0x%x",
578			ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
579		if (sp->country != NULL)
580			dump_country(sp->country);
581		printf("\n");
582	}
583}
584#endif /* IEEE80211_DEBUG */
585
586/*
587 * Process a beacon or probe response frame.
588 */
589void
590ieee80211_add_scan(struct ieee80211vap *vap,
591	struct ieee80211_channel *curchan,
592	const struct ieee80211_scanparams *sp,
593	const struct ieee80211_frame *wh,
594	int subtype, int rssi, int noise)
595{
596	struct ieee80211com *ic = vap->iv_ic;
597
598	return (ic->ic_scan_methods->sc_add_scan(vap, curchan, sp, wh, subtype,
599	    rssi, noise));
600}
601
602/*
603 * Timeout/age scan cache entries; called from sta timeout
604 * timer (XXX should be self-contained).
605 */
606void
607ieee80211_scan_timeout(struct ieee80211com *ic)
608{
609	struct ieee80211_scan_state *ss = ic->ic_scan;
610
611	if (ss->ss_ops != NULL)
612		ss->ss_ops->scan_age(ss);
613}
614
615/*
616 * Mark a scan cache entry after a successful associate.
617 */
618void
619ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
620{
621	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
622
623	if (ss->ss_ops != NULL) {
624		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
625			mac, "%s",  __func__);
626		ss->ss_ops->scan_assoc_success(ss, mac);
627	}
628}
629
630/*
631 * Demerit a scan cache entry after failing to associate.
632 */
633void
634ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
635	const uint8_t mac[], int reason)
636{
637	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
638
639	if (ss->ss_ops != NULL) {
640		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
641			"%s: reason %u", __func__, reason);
642		ss->ss_ops->scan_assoc_fail(ss, mac, reason);
643	}
644}
645
646/*
647 * Iterate over the contents of the scan cache.
648 */
649void
650ieee80211_scan_iterate(struct ieee80211vap *vap,
651	ieee80211_scan_iter_func *f, void *arg)
652{
653	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
654
655	if (ss->ss_ops != NULL)
656		ss->ss_ops->scan_iterate(ss, f, arg);
657}
658
659/*
660 * Flush the contents of the scan cache.
661 */
662void
663ieee80211_scan_flush(struct ieee80211vap *vap)
664{
665	struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
666
667	if (ss->ss_ops != NULL && ss->ss_vap == vap) {
668		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
669		ss->ss_ops->scan_flush(ss);
670	}
671}
672
673/*
674 * Check the scan cache for an ap/channel to use; if that
675 * fails then kick off a new scan.
676 */
677struct ieee80211_channel *
678ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
679{
680	struct ieee80211_scan_state *ss = ic->ic_scan;
681
682	IEEE80211_LOCK_ASSERT(ic);
683
684	if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
685		/* XXX printf? */
686		return NULL;
687	}
688	if (ss->ss_ops->scan_pickchan == NULL) {
689		IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
690		    "%s: scan module does not support picking a channel, "
691		    "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
692		return NULL;
693	}
694	return ss->ss_ops->scan_pickchan(ss, flags);
695}
696