wlan - Rip out all wlan locks part 1/2
[dragonfly.git] / sys / netproto / 802_11 / wlan / ieee80211_scan.c
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  * $FreeBSD: head/sys/net80211/ieee80211_scan.c 195618 2009-07-11 15:02:45Z rpaulo $
26  * $DragonFly$
27  */
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  
39 #include <sys/condvar.h>
40 #include <sys/socket.h>
41
42 #include <net/if.h>
43 #include <net/if_media.h>
44 #include <net/ethernet.h>
45 #include <net/route.h>
46
47 #include <netproto/802_11/ieee80211_var.h>
48
49 #include <net/bpf.h>
50
51 struct scan_state {
52         struct ieee80211_scan_state base;       /* public state */
53
54         u_int           ss_iflags;              /* flags used internally */
55 #define ISCAN_MINDWELL  0x0001          /* min dwell time reached */
56 #define ISCAN_DISCARD   0x0002          /* discard rx'd frames */
57 #define ISCAN_CANCEL    0x0004          /* cancel current scan */
58 #define ISCAN_ABORT     0x0008          /* end the scan immediately */
59         unsigned long   ss_chanmindwell;        /* min dwell on curchan */
60         unsigned long   ss_scanend;             /* time scan must stop */
61         u_int           ss_duration;            /* duration for next scan */
62         struct task     ss_scan_task;           /* scan execution */
63         struct cv       ss_scan_cv;             /* scan signal */
64         struct callout  ss_scan_timer;          /* scan timer */
65 };
66 #define SCAN_PRIVATE(ss)        ((struct scan_state *) ss)
67
68 /*
69  * Amount of time to go off-channel during a background
70  * scan.  This value should be large enough to catch most
71  * ap's but short enough that we can return on-channel
72  * before our listen interval expires.
73  *
74  * XXX tunable
75  * XXX check against configured listen interval
76  */
77 #define IEEE80211_SCAN_OFFCHANNEL       msecs_to_ticks(150)
78
79 /*
80  * Roaming-related defaults.  RSSI thresholds are as returned by the
81  * driver (.5dBm).  Transmit rate thresholds are IEEE rate codes (i.e
82  * .5M units) or MCS.
83  */
84 /* rssi thresholds */
85 #define ROAM_RSSI_11A_DEFAULT           14      /* 11a bss */
86 #define ROAM_RSSI_11B_DEFAULT           14      /* 11b bss */
87 #define ROAM_RSSI_11BONLY_DEFAULT       14      /* 11b-only bss */
88 /* transmit rate thresholds */
89 #define ROAM_RATE_11A_DEFAULT           2*12    /* 11a bss */
90 #define ROAM_RATE_11B_DEFAULT           2*5     /* 11b bss */
91 #define ROAM_RATE_11BONLY_DEFAULT       2*1     /* 11b-only bss */
92 #define ROAM_RATE_HALF_DEFAULT          2*6     /* half-width 11a/g bss */
93 #define ROAM_RATE_QUARTER_DEFAULT       2*3     /* quarter-width 11a/g bss */
94 #define ROAM_MCS_11N_DEFAULT            (1 | IEEE80211_RATE_MCS) /* 11n bss */
95
96 static  void scan_curchan(struct ieee80211_scan_state *, unsigned long);
97 static  void scan_mindwell(struct ieee80211_scan_state *);
98 static  void scan_signal(void *);
99 static  void scan_task(void *, int);
100
101 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
102
103 void
104 ieee80211_scan_attach(struct ieee80211com *ic)
105 {
106         struct scan_state *ss;
107
108         ss = (struct scan_state *) kmalloc(sizeof(struct scan_state),
109                 M_80211_SCAN, M_INTWAIT | M_ZERO);
110         if (ss == NULL) {
111                 ic->ic_scan = NULL;
112                 return;
113         }
114         wlan_cv_init(&ss->ss_scan_cv, "scan");
115         callout_init(&ss->ss_scan_timer);
116         TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
117         ic->ic_scan = &ss->base;
118         ss->base.ss_ic = ic;
119
120         ic->ic_scan_curchan = scan_curchan;
121         ic->ic_scan_mindwell = scan_mindwell;
122 }
123
124 void
125 ieee80211_scan_detach(struct ieee80211com *ic)
126 {
127         struct ieee80211_scan_state *ss = ic->ic_scan;
128
129         if (ss != NULL) {
130                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
131                 scan_signal(ss);
132                 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
133                 callout_stop(&SCAN_PRIVATE(ss)->ss_scan_timer);
134                 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
135                     ("scan still running"));
136                 if (ss->ss_ops != NULL) {
137                         ss->ss_ops->scan_detach(ss);
138                         ss->ss_ops = NULL;
139                 }
140                 ic->ic_scan = NULL;
141                 kfree(SCAN_PRIVATE(ss), M_80211_SCAN);
142         }
143 }
144
145 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
146         [IEEE80211_MODE_11A]    = { .rssi = ROAM_RSSI_11A_DEFAULT,
147                                     .rate = ROAM_RATE_11A_DEFAULT },
148         [IEEE80211_MODE_11G]    = { .rssi = ROAM_RSSI_11B_DEFAULT,
149                                     .rate = ROAM_RATE_11B_DEFAULT },
150         [IEEE80211_MODE_11B]    = { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
151                                     .rate = ROAM_RATE_11BONLY_DEFAULT },
152         [IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
153                                     .rate = ROAM_RATE_11A_DEFAULT },
154         [IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
155                                     .rate = ROAM_RATE_11A_DEFAULT },
156         [IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
157                                     .rate = ROAM_RATE_11A_DEFAULT },
158         [IEEE80211_MODE_HALF]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
159                                     .rate = ROAM_RATE_HALF_DEFAULT },
160         [IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
161                                     .rate = ROAM_RATE_QUARTER_DEFAULT },
162         [IEEE80211_MODE_11NA]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
163                                     .rate = ROAM_MCS_11N_DEFAULT },
164         [IEEE80211_MODE_11NG]   = { .rssi = ROAM_RSSI_11B_DEFAULT,
165                                     .rate = ROAM_MCS_11N_DEFAULT },
166 };
167
168 void
169 ieee80211_scan_vattach(struct ieee80211vap *vap)
170 {
171         vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
172         vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
173         vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
174
175         vap->iv_roaming = IEEE80211_ROAMING_AUTO;
176         memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
177 }
178
179 void
180 ieee80211_scan_vdetach(struct ieee80211vap *vap)
181 {
182         struct ieee80211com *ic = vap->iv_ic;
183         struct ieee80211_scan_state *ss;
184
185         ss = ic->ic_scan;
186         if (ss != NULL && ss->ss_vap == vap) {
187                 if (ic->ic_flags & IEEE80211_F_SCAN) {
188                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
189                         scan_signal(ss);
190                 }
191                 if (ss->ss_ops != NULL) {
192                         ss->ss_ops->scan_detach(ss);
193                         ss->ss_ops = NULL;
194                 }
195                 ss->ss_vap = NULL;
196         }
197 }
198
199 /*
200  * Simple-minded scanner module support.
201  */
202 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
203         "wlan_scan_sta",        /* IEEE80211_M_IBSS */
204         "wlan_scan_sta",        /* IEEE80211_M_STA */
205         "wlan_scan_wds",        /* IEEE80211_M_WDS */
206         "wlan_scan_sta",        /* IEEE80211_M_AHDEMO */
207         "wlan_scan_ap",         /* IEEE80211_M_HOSTAP */
208         "wlan_scan_monitor",    /* IEEE80211_M_MONITOR */
209         "wlan_scan_sta",        /* IEEE80211_M_MBSS */
210 };
211 static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
212
213 const struct ieee80211_scanner *
214 ieee80211_scanner_get(enum ieee80211_opmode mode)
215 {
216         if (mode >= IEEE80211_OPMODE_MAX)
217                 return NULL;
218         if (scanners[mode] == NULL)
219                 ieee80211_load_module(scan_modnames[mode]);
220         return scanners[mode];
221 }
222
223 void
224 ieee80211_scanner_register(enum ieee80211_opmode mode,
225         const struct ieee80211_scanner *scan)
226 {
227         if (mode >= IEEE80211_OPMODE_MAX)
228                 return;
229         scanners[mode] = scan;
230 }
231
232 void
233 ieee80211_scanner_unregister(enum ieee80211_opmode mode,
234         const struct ieee80211_scanner *scan)
235 {
236         if (mode >= IEEE80211_OPMODE_MAX)
237                 return;
238         if (scanners[mode] == scan)
239                 scanners[mode] = NULL;
240 }
241
242 void
243 ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
244 {
245         int m;
246
247         for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
248                 if (scanners[m] == scan)
249                         scanners[m] = NULL;
250 }
251
252 /*
253  * Update common scanner state to reflect the current
254  * operating mode.  This is called when the state machine
255  * is transitioned to RUN state w/o scanning--e.g. when
256  * operating in monitor mode.  The purpose of this is to
257  * ensure later callbacks find ss_ops set to properly
258  * reflect current operating mode.
259  */
260 static void
261 scan_update_locked(struct ieee80211vap *vap,
262         const struct ieee80211_scanner *scan)
263 {
264         struct ieee80211com *ic = vap->iv_ic;
265         struct ieee80211_scan_state *ss = ic->ic_scan;
266
267 #ifdef IEEE80211_DEBUG
268         if (ss->ss_vap != vap || ss->ss_ops != scan) {
269                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
270                     "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
271                     __func__,
272                     ss->ss_vap != NULL ?
273                         ss->ss_vap->iv_ifp->if_xname : "none",
274                     ss->ss_vap != NULL ?
275                         ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
276                     vap->iv_ifp->if_xname,
277                     ieee80211_opmode_name[vap->iv_opmode]);
278         }
279 #endif
280         ss->ss_vap = vap;
281         if (ss->ss_ops != scan) {
282                 /*
283                  * Switch scanners; detach old, attach new.  Special
284                  * case where a single scan module implements multiple
285                  * policies by using different scan ops but a common
286                  * core.  We assume if the old and new attach methods
287                  * are identical then it's ok to just change ss_ops
288                  * and not flush the internal state of the module.
289                  */
290                 if (scan == NULL || ss->ss_ops == NULL ||
291                     ss->ss_ops->scan_attach != scan->scan_attach) {
292                         if (ss->ss_ops != NULL)
293                                 ss->ss_ops->scan_detach(ss);
294                         if (scan != NULL && !scan->scan_attach(ss)) {
295                                 /* XXX attach failure */
296                                 /* XXX stat+msg */
297                                 scan = NULL;
298                         }
299                 }
300                 ss->ss_ops = scan;
301         }
302 }
303
304 static char
305 channel_type(const struct ieee80211_channel *c)
306 {
307         if (IEEE80211_IS_CHAN_ST(c))
308                 return 'S';
309         if (IEEE80211_IS_CHAN_108A(c))
310                 return 'T';
311         if (IEEE80211_IS_CHAN_108G(c))
312                 return 'G';
313         if (IEEE80211_IS_CHAN_HT(c))
314                 return 'n';
315         if (IEEE80211_IS_CHAN_A(c))
316                 return 'a';
317         if (IEEE80211_IS_CHAN_ANYG(c))
318                 return 'g';
319         if (IEEE80211_IS_CHAN_B(c))
320                 return 'b';
321         return 'f';
322 }
323
324 void
325 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
326 {
327         struct ieee80211com *ic = ss->ss_ic;
328         const char *sep;
329         int i;
330
331         sep = "";
332         for (i = ss->ss_next; i < ss->ss_last; i++) {
333                 const struct ieee80211_channel *c = ss->ss_chans[i];
334
335                 kprintf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
336                         channel_type(c));
337                 sep = ", ";
338         }
339 }
340
341 #ifdef IEEE80211_DEBUG
342 static void
343 scan_dump(struct ieee80211_scan_state *ss)
344 {
345         struct ieee80211vap *vap = ss->ss_vap;
346
347         if_printf(vap->iv_ifp, "scan set ");
348         ieee80211_scan_dump_channels(ss);
349         kprintf(" dwell min %lums max %lums\n",
350             ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
351 }
352 #endif /* IEEE80211_DEBUG */
353
354 static void
355 copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
356         int nssid, const struct ieee80211_scan_ssid ssids[])
357 {
358         if (nssid > IEEE80211_SCAN_MAX_SSID) {
359                 /* XXX printf */
360                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
361                     "%s: too many ssid %d, ignoring all of them\n",
362                     __func__, nssid);
363                 return;
364         }
365         memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
366         ss->ss_nssid = nssid;
367 }
368
369 /*
370  * Start a scan unless one is already going.
371  */
372 static int
373 start_scan_locked(const struct ieee80211_scanner *scan,
374         struct ieee80211vap *vap, int flags, u_int duration,
375         u_int mindwell, u_int maxdwell,
376         u_int nssid, const struct ieee80211_scan_ssid ssids[])
377 {
378         struct ieee80211com *ic = vap->iv_ic;
379         struct ieee80211_scan_state *ss = ic->ic_scan;
380
381         if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
382                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
383                     "%s: scan inhibited by pending channel change\n", __func__);
384         } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
385                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
386                     "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
387                     , __func__
388                     , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
389                     , duration, mindwell, maxdwell
390                     , ieee80211_phymode_name[vap->iv_des_mode]
391                     , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
392                     , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
393                     , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
394                     , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
395                     , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
396                     , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
397                 );
398
399                 scan_update_locked(vap, scan);
400                 if (ss->ss_ops != NULL) {
401                         if ((flags & IEEE80211_SCAN_NOSSID) == 0)
402                                 copy_ssid(vap, ss, nssid, ssids);
403
404                         /* NB: top 4 bits for internal use */
405                         ss->ss_flags = flags & 0xfff;
406                         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
407                                 vap->iv_stats.is_scan_active++;
408                         else
409                                 vap->iv_stats.is_scan_passive++;
410                         if (flags & IEEE80211_SCAN_FLUSH)
411                                 ss->ss_ops->scan_flush(ss);
412
413                         /* NB: flush frames rx'd before 1st channel change */
414                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
415                         SCAN_PRIVATE(ss)->ss_duration = duration;
416                         ss->ss_next = 0;
417                         ss->ss_mindwell = mindwell;
418                         ss->ss_maxdwell = maxdwell;
419                         /* NB: scan_start must be before the scan runtask */
420                         ss->ss_ops->scan_start(ss, vap);
421 #ifdef IEEE80211_DEBUG
422                         if (ieee80211_msg_scan(vap))
423                                 scan_dump(ss);
424 #endif /* IEEE80211_DEBUG */
425                         ic->ic_flags |= IEEE80211_F_SCAN;
426                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
427                 }
428         } else {
429                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
430                     "%s: %s scan already in progress\n", __func__,
431                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
432         }
433         return (ic->ic_flags & IEEE80211_F_SCAN);
434 }
435
436 /*
437  * Start a scan unless one is already going.
438  */
439 int
440 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
441         u_int duration, u_int mindwell, u_int maxdwell,
442         u_int nssid, const struct ieee80211_scan_ssid ssids[])
443 {
444         struct ieee80211com *ic = vap->iv_ic;
445         const struct ieee80211_scanner *scan;
446         int result;
447
448         ic = vap->iv_ic;
449         scan = ieee80211_scanner_get(vap->iv_opmode);
450         if (scan == NULL) {
451                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
452                     "%s: no scanner support for %s mode\n",
453                     __func__, ieee80211_opmode_name[vap->iv_opmode]);
454                 /* XXX stat */
455                 return 0;
456         }
457
458         result = start_scan_locked(scan, vap, flags, duration,
459             mindwell, maxdwell, nssid, ssids);
460
461         return result;
462 }
463
464 /*
465  * Check the scan cache for an ap/channel to use; if that
466  * fails then kick off a new scan.
467  */
468 int
469 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
470         u_int duration, u_int mindwell, u_int maxdwell,
471         u_int nssid, const struct ieee80211_scan_ssid ssids[])
472 {
473         struct ieee80211com *ic = vap->iv_ic;
474         struct ieee80211_scan_state *ss = ic->ic_scan;
475         const struct ieee80211_scanner *scan;
476         int result;
477
478         scan = ieee80211_scanner_get(vap->iv_opmode);
479         if (scan == NULL) {
480                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
481                     "%s: no scanner support for %s mode\n",
482                     __func__, vap->iv_opmode);
483                 /* XXX stat */
484                 return 0;
485         }
486
487         /*
488          * Check if there's a list of scan candidates already.
489          * XXX want more than the ap we're currently associated with
490          */
491
492         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
493             "%s: %s scan, %s%s%s%s%s\n"
494             , __func__
495             , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
496             , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
497             , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
498             , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
499             , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
500             , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
501         );
502
503         if (ss->ss_ops != scan) {
504                 /* XXX re-use cache contents? e.g. adhoc<->sta */
505                 flags |= IEEE80211_SCAN_FLUSH;
506         }
507         scan_update_locked(vap, scan);
508         if (ss->ss_ops != NULL) {
509                 /* XXX verify ss_ops matches vap->iv_opmode */
510                 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
511                         /*
512                          * Update the ssid list and mark flags so if
513                          * we call start_scan it doesn't duplicate work.
514                          */
515                         copy_ssid(vap, ss, nssid, ssids);
516                         flags |= IEEE80211_SCAN_NOSSID;
517                 }
518                 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
519                     (flags & IEEE80211_SCAN_FLUSH) == 0 &&
520                     time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
521                         /*
522                          * We're not currently scanning and the cache is
523                          * deemed hot enough to consult.  Lock out others
524                          * by marking IEEE80211_F_SCAN while we decide if
525                          * something is already in the scan cache we can
526                          * use.  Also discard any frames that might come
527                          * in while temporarily marked as scanning.
528                          */
529                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
530                         ic->ic_flags |= IEEE80211_F_SCAN;
531
532                         /* NB: need to use supplied flags in check */
533                         ss->ss_flags = flags & 0xff;
534                         result = ss->ss_ops->scan_end(ss, vap);
535
536                         ic->ic_flags &= ~IEEE80211_F_SCAN;
537                         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
538                         if (result) {
539                                 ieee80211_notify_scan_done(vap);
540                                 return 1;
541                         }
542                 }
543         }
544         result = start_scan_locked(scan, vap, flags, duration,
545             mindwell, maxdwell, nssid, ssids);
546
547         return result;
548 }
549
550 /*
551  * Check the scan cache for an ap/channel to use; if that fails
552  * then kick off a scan using the current settings.
553  */
554 int
555 ieee80211_check_scan_current(struct ieee80211vap *vap)
556 {
557         return ieee80211_check_scan(vap,
558             IEEE80211_SCAN_ACTIVE,
559             IEEE80211_SCAN_FOREVER, 0, 0,
560             vap->iv_des_nssid, vap->iv_des_ssid);
561 }
562
563 /*
564  * Restart a previous scan.  If the previous scan completed
565  * then we start again using the existing channel list.
566  */
567 int
568 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
569 {
570         struct ieee80211com *ic = vap->iv_ic;
571         struct ieee80211_scan_state *ss = ic->ic_scan;
572         const struct ieee80211_scanner *scan;
573
574         scan = ieee80211_scanner_get(vap->iv_opmode);
575         if (scan == NULL) {
576                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
577                     "%s: no scanner support for %s mode\n",
578                     __func__, vap->iv_opmode);
579                 /* XXX stat */
580                 return 0;
581         }
582
583         if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
584                 u_int duration;
585                 /*
586                  * Go off-channel for a fixed interval that is large
587                  * enough to catch most ap's but short enough that
588                  * we can return on-channel before our listen interval
589                  * expires.
590                  */
591                 duration = IEEE80211_SCAN_OFFCHANNEL;
592
593                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
594                     "%s: %s scan, ticks %u duration %lu\n", __func__,
595                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
596                     ticks, duration);
597
598                 scan_update_locked(vap, scan);
599                 if (ss->ss_ops != NULL) {
600                         ss->ss_vap = vap;
601                         /*
602                          * A background scan does not select a new sta; it
603                          * just refreshes the scan cache.  Also, indicate
604                          * the scan logic should follow the beacon schedule:
605                          * we go off-channel and scan for a while, then
606                          * return to the bss channel to receive a beacon,
607                          * then go off-channel again.  All during this time
608                          * we notify the ap we're in power save mode.  When
609                          * the scan is complete we leave power save mode.
610                          * If any beacon indicates there are frames pending
611                          * for us then we drop out of power save mode
612                          * (and background scan) automatically by way of the
613                          * usual sta power save logic.
614                          */
615                         ss->ss_flags |= IEEE80211_SCAN_NOPICK
616                                      |  IEEE80211_SCAN_BGSCAN
617                                      |  flags
618                                      ;
619                         /* if previous scan completed, restart */
620                         if (ss->ss_next >= ss->ss_last) {
621                                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
622                                         vap->iv_stats.is_scan_active++;
623                                 else
624                                         vap->iv_stats.is_scan_passive++;
625                                 /*
626                                  * NB: beware of the scan cache being flushed;
627                                  *     if the channel list is empty use the
628                                  *     scan_start method to populate it.
629                                  */
630                                 ss->ss_next = 0;
631                                 if (ss->ss_last != 0)
632                                         ss->ss_ops->scan_restart(ss, vap);
633                                 else {
634                                         ss->ss_ops->scan_start(ss, vap);
635 #ifdef IEEE80211_DEBUG
636                                         if (ieee80211_msg_scan(vap))
637                                                 scan_dump(ss);
638 #endif /* IEEE80211_DEBUG */
639                                 }
640                         }
641                         /* NB: flush frames rx'd before 1st channel change */
642                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
643                         SCAN_PRIVATE(ss)->ss_duration = duration;
644                         ss->ss_maxdwell = duration;
645                         ic->ic_flags |= IEEE80211_F_SCAN;
646                         ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
647                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
648                 } else {
649                         /* XXX msg+stat */
650                 }
651         } else {
652                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
653                     "%s: %s scan already in progress\n", __func__,
654                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
655         }
656
657         /* NB: racey, does it matter? */
658         return (ic->ic_flags & IEEE80211_F_SCAN);
659 }
660
661 /*
662  * Cancel any scan currently going on for the specified vap.
663  */
664 void
665 ieee80211_cancel_scan(struct ieee80211vap *vap)
666 {
667         struct ieee80211com *ic = vap->iv_ic;
668         struct ieee80211_scan_state *ss = ic->ic_scan;
669
670         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
671             ss->ss_vap == vap &&
672             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
673                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
674                     "%s: cancel %s scan\n", __func__,
675                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
676                         "active" : "passive");
677
678                 /* clear bg scan NOPICK and mark cancel request */
679                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
680                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
681                 /* wake up the scan task */
682                 scan_signal(ss);
683         }
684 }
685
686 /*
687  * Cancel any scan currently going on.
688  */
689 void
690 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
691 {
692         struct ieee80211com *ic = vap->iv_ic;
693         struct ieee80211_scan_state *ss = ic->ic_scan;
694
695         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
696             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
697                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
698                     "%s: cancel %s scan\n", __func__,
699                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
700                         "active" : "passive");
701
702                 /* clear bg scan NOPICK and mark cancel request */
703                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
704                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
705                 /* wake up the scan task */
706                 scan_signal(ss);
707         }
708 }
709
710 /*
711  * Public access to scan_next for drivers that manage
712  * scanning themselves (e.g. for firmware-based devices).
713  */
714 void
715 ieee80211_scan_next(struct ieee80211vap *vap)
716 {
717         struct ieee80211com *ic = vap->iv_ic;
718         struct ieee80211_scan_state *ss = ic->ic_scan;
719
720         /* wake up the scan task */
721         scan_signal(ss);
722 }
723
724 /*
725  * Public access to scan_next for drivers that are not able to scan single
726  * channels (e.g. for firmware-based devices).
727  */
728 void
729 ieee80211_scan_done(struct ieee80211vap *vap)
730 {
731         struct ieee80211com *ic = vap->iv_ic;
732         struct ieee80211_scan_state *ss;
733
734         ss = ic->ic_scan;
735         ss->ss_next = ss->ss_last; /* all channels are complete */
736         scan_signal(ss);
737 }
738
739 /*
740  * Probe the curent channel, if allowed, while scanning.
741  * If the channel is not marked passive-only then send
742  * a probe request immediately.  Otherwise mark state and
743  * listen for beacons on the channel; if we receive something
744  * then we'll transmit a probe request.
745  */
746 void
747 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
748 {
749         struct ieee80211com *ic = vap->iv_ic;
750         struct ieee80211_scan_state *ss = ic->ic_scan;
751         struct ifnet *ifp = vap->iv_ifp;
752         int i;
753
754         if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
755                 ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
756                 return;
757         }
758         /*
759          * Send directed probe requests followed by any
760          * broadcast probe request.
761          * XXX remove dependence on ic/vap->iv_bss
762          */
763         for (i = 0; i < ss->ss_nssid; i++)
764                 ieee80211_send_probereq(vap->iv_bss,
765                         vap->iv_myaddr, ifp->if_broadcastaddr,
766                         ifp->if_broadcastaddr,
767                         ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
768         if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
769                 ieee80211_send_probereq(vap->iv_bss,
770                         vap->iv_myaddr, ifp->if_broadcastaddr,
771                         ifp->if_broadcastaddr,
772                         "", 0);
773 }
774
775 /*
776  * Scan curchan.  If this is an active scan and the channel
777  * is not marked passive then send probe request frame(s).
778  * Arrange for the channel change after maxdwell ticks.
779  */
780 static void
781 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
782 {
783         struct ieee80211vap *vap  = ss->ss_vap;
784
785         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
786                 ieee80211_probe_curchan(vap, 0);
787         callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
788             maxdwell, scan_signal, ss);
789 }
790
791 static void
792 scan_signal(void *arg)
793 {
794         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
795
796         wlan_cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv, 0);
797 }
798
799 /*
800  * Handle mindwell requirements completed; initiate a channel
801  * change to the next channel asap.
802  */
803 static void
804 scan_mindwell(struct ieee80211_scan_state *ss)
805 {
806         struct ieee80211com *ic = ss->ss_ic;
807
808         ic = ss->ss_ic;
809         scan_signal(ss);
810 }
811
812 static void
813 scan_task(void *arg, int pending)
814 {
815 #define ISCAN_REP       (ISCAN_MINDWELL | ISCAN_DISCARD)
816         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
817         struct ieee80211vap *vap = ss->ss_vap;
818         struct ieee80211com *ic = ss->ss_ic;
819         struct ieee80211_channel *chan;
820         unsigned long maxdwell, scanend;
821         int scandone = 0;
822
823         if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
824             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
825                 /* Cancelled before we started */
826                 goto done;
827         }
828
829         if (ss->ss_next == ss->ss_last) {
830                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
831                         "%s: no channels to scan\n", __func__);
832                 goto done;
833         }
834
835         if (vap->iv_opmode == IEEE80211_M_STA &&
836             vap->iv_state == IEEE80211_S_RUN) {
837                 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
838                         /* Enable station power save mode */
839                         ieee80211_sta_pwrsave(vap, 1);
840                         /*
841                          * Use an 1ms delay so the null data frame has a chance
842                          * to go out.  Minimum one tick.
843                          * XXX Should use M_TXCB mechanism to eliminate this.
844                          */
845                         wlan_cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
846                                           hz / 1000 + 1);
847                         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
848                                 goto done;
849                 }
850         }
851
852         scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
853         ic->ic_scan_start(ic);          /* notify driver */
854
855         for (;;) {
856                 scandone = (ss->ss_next >= ss->ss_last) ||
857                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
858                 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
859                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
860                      time_after(ticks + ss->ss_mindwell, scanend))
861                         break;
862
863                 chan = ss->ss_chans[ss->ss_next++];
864
865                 /*
866                  * Watch for truncation due to the scan end time.
867                  */
868                 if (time_after(ticks + ss->ss_maxdwell, scanend))
869                         maxdwell = scanend - ticks;
870                 else
871                         maxdwell = ss->ss_maxdwell;
872
873                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
874                     "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
875                     __func__,
876                     ieee80211_chan2ieee(ic, ic->ic_curchan),
877                         channel_type(ic->ic_curchan),
878                     ieee80211_chan2ieee(ic, chan), channel_type(chan),
879                     (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
880                         (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
881                         "active" : "passive",
882                     ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
883
884                 /*
885                  * Potentially change channel and phy mode.
886                  */
887                 ic->ic_curchan = chan;
888                 ic->ic_rt = ieee80211_get_ratetable(chan);
889                 /*
890                  * Perform the channel change and scan unlocked so the driver
891                  * may sleep. Once set_channel returns the hardware has
892                  * completed the channel change.
893                  */
894                 ic->ic_set_channel(ic);
895                 ieee80211_radiotap_chan_change(ic);
896
897                 /*
898                  * Scan curchan.  Drivers for "intelligent hardware"
899                  * override ic_scan_curchan to tell the device to do
900                  * the work.  Otherwise we manage the work outselves;
901                  * sending a probe request (as needed), and arming the
902                  * timeout to switch channels after maxdwell ticks.
903                  *
904                  * scan_curchan should only pause for the time required to
905                  * prepare/initiate the hardware for the scan (if at all), the
906                  * below condvar is used to sleep for the channels dwell time
907                  * and allows it to be signalled for abort.
908                  */
909                 ic->ic_scan_curchan(ss, maxdwell);
910
911                 SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
912                 /* clear mindwell lock and initial channel change flush */
913                 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
914
915                 if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
916                         continue;
917
918                 /* Wait to be signalled to scan the next channel */
919                 wlan_cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv);
920         }
921         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
922                 goto done;
923
924         ic->ic_scan_end(ic);            /* notify driver */
925
926         /*
927          * Record scan complete time.  Note that we also do
928          * this when canceled so any background scan will
929          * not be restarted for a while.
930          */
931         if (scandone)
932                 ic->ic_lastscan = ticks;
933         /* return to the bss channel */
934         if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
935             ic->ic_curchan != ic->ic_bsschan) {
936                 ieee80211_setupcurchan(ic, ic->ic_bsschan);
937                 ic->ic_set_channel(ic);
938                 ieee80211_radiotap_chan_change(ic);
939         }
940         /* clear internal flags and any indication of a pick */
941         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
942         ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
943
944         /*
945          * If not canceled and scan completed, do post-processing.
946          * If the callback function returns 0, then it wants to
947          * continue/restart scanning.  Unfortunately we needed to
948          * notify the driver to end the scan above to avoid having
949          * rx frames alter the scan candidate list.
950          */
951         if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
952             !ss->ss_ops->scan_end(ss, vap) &&
953             (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
954             time_before(ticks + ss->ss_mindwell, scanend)) {
955                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
956                     "%s: done, restart "
957                     "[ticks %u, dwell min %lu scanend %lu]\n",
958                     __func__,
959                     ticks, ss->ss_mindwell, scanend);
960                 ss->ss_next = 0;        /* reset to begining */
961                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
962                         vap->iv_stats.is_scan_active++;
963                 else
964                         vap->iv_stats.is_scan_passive++;
965
966                 ss->ss_ops->scan_restart(ss, vap);      /* XXX? */
967                 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
968                 return;
969         }
970
971         /* past here, scandone is ``true'' if not in bg mode */
972         if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
973                 scandone = 1;
974
975         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
976             "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
977             __func__, scandone ? "done" : "stopped",
978             ticks, ss->ss_mindwell, scanend);
979
980         /*
981          * Clear the SCAN bit first in case frames are
982          * pending on the station power save queue.  If
983          * we defer this then the dispatch of the frames
984          * may generate a request to cancel scanning.
985          */
986 done:
987         ic->ic_flags &= ~IEEE80211_F_SCAN;
988         /*
989          * Drop out of power save mode when a scan has
990          * completed.  If this scan was prematurely terminated
991          * because it is a background scan then don't notify
992          * the ap; we'll either return to scanning after we
993          * receive the beacon frame or we'll drop out of power
994          * save mode because the beacon indicates we have frames
995          * waiting for us.
996          */
997         if (scandone) {
998                 ieee80211_sta_pwrsave(vap, 0);
999                 if (ss->ss_next >= ss->ss_last) {
1000                         ieee80211_notify_scan_done(vap);
1001                         ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
1002                 }
1003         }
1004         SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
1005         ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
1006 #undef ISCAN_REP
1007 }
1008
1009 #ifdef IEEE80211_DEBUG
1010 static void
1011 dump_country(const uint8_t *ie)
1012 {
1013         const struct ieee80211_country_ie *cie =
1014            (const struct ieee80211_country_ie *) ie;
1015         int i, nbands, schan, nchan;
1016
1017         if (cie->len < 3) {
1018                 kprintf(" <bogus country ie, len %d>", cie->len);
1019                 return;
1020         }
1021         kprintf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
1022         nbands = (cie->len - 3) / sizeof(cie->band[0]);
1023         for (i = 0; i < nbands; i++) {
1024                 schan = cie->band[i].schan;
1025                 nchan = cie->band[i].nchan;
1026                 if (nchan != 1)
1027                         kprintf(" %u-%u,%u", schan, schan + nchan-1,
1028                             cie->band[i].maxtxpwr);
1029                 else
1030                         kprintf(" %u,%u", schan, cie->band[i].maxtxpwr);
1031         }
1032         kprintf("]");
1033 }
1034
1035 static void
1036 dump_probe_beacon(uint8_t subtype, int isnew,
1037         const uint8_t mac[IEEE80211_ADDR_LEN],
1038         const struct ieee80211_scanparams *sp, int rssi)
1039 {
1040
1041         kprintf("[%6D] %s%s on chan %u (bss chan %u) ",
1042             mac, ":", isnew ? "new " : "",
1043             ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
1044             sp->chan, sp->bchan);
1045         ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
1046         kprintf(" rssi %d\n", rssi);
1047
1048         if (isnew) {
1049                 kprintf("[%6D] caps 0x%x bintval %u erp 0x%x", 
1050                         mac, ":", sp->capinfo, sp->bintval, sp->erp);
1051                 if (sp->country != NULL)
1052                         dump_country(sp->country);
1053                 kprintf("\n");
1054         }
1055 }
1056 #endif /* IEEE80211_DEBUG */
1057
1058 /*
1059  * Process a beacon or probe response frame.
1060  */
1061 void
1062 ieee80211_add_scan(struct ieee80211vap *vap,
1063         const struct ieee80211_scanparams *sp,
1064         const struct ieee80211_frame *wh,
1065         int subtype, int rssi, int noise)
1066 {
1067         struct ieee80211com *ic = vap->iv_ic;
1068         struct ieee80211_scan_state *ss = ic->ic_scan;
1069
1070         /* XXX locking */
1071         /*
1072          * Frames received during startup are discarded to avoid
1073          * using scan state setup on the initial entry to the timer
1074          * callback.  This can occur because the device may enable
1075          * rx prior to our doing the initial channel change in the
1076          * timer routine.
1077          */
1078         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
1079                 return;
1080 #ifdef IEEE80211_DEBUG
1081         if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
1082                 dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
1083 #endif
1084         if (ss->ss_ops != NULL &&
1085             ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, noise)) {
1086                 /*
1087                  * If we've reached the min dwell time terminate
1088                  * the timer so we'll switch to the next channel.
1089                  */
1090                 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
1091                     time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
1092                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1093                             "%s: chan %3d%c min dwell met (%u > %lu)\n",
1094                             __func__,
1095                             ieee80211_chan2ieee(ic, ic->ic_curchan),
1096                                 channel_type(ic->ic_curchan),
1097                             ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
1098                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
1099                         /*
1100                          * NB: trigger at next clock tick or wait for the
1101                          * hardware.
1102                          */
1103                         ic->ic_scan_mindwell(ss);
1104                 }
1105         }
1106 }
1107
1108 /*
1109  * Timeout/age scan cache entries; called from sta timeout
1110  * timer (XXX should be self-contained).
1111  */
1112 void
1113 ieee80211_scan_timeout(struct ieee80211com *ic)
1114 {
1115         struct ieee80211_scan_state *ss = ic->ic_scan;
1116
1117         if (ss->ss_ops != NULL)
1118                 ss->ss_ops->scan_age(ss);
1119 }
1120
1121 /*
1122  * Mark a scan cache entry after a successful associate.
1123  */
1124 void
1125 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
1126 {
1127         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1128
1129         if (ss->ss_ops != NULL) {
1130                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
1131                         mac, "%s",  __func__);
1132                 ss->ss_ops->scan_assoc_success(ss, mac);
1133         }
1134 }
1135
1136 /*
1137  * Demerit a scan cache entry after failing to associate.
1138  */
1139 void
1140 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
1141         const uint8_t mac[], int reason)
1142 {
1143         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1144
1145         if (ss->ss_ops != NULL) {
1146                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
1147                         "%s: reason %u", __func__, reason);
1148                 ss->ss_ops->scan_assoc_fail(ss, mac, reason);
1149         }
1150 }
1151
1152 /*
1153  * Iterate over the contents of the scan cache.
1154  */
1155 void
1156 ieee80211_scan_iterate(struct ieee80211vap *vap,
1157         ieee80211_scan_iter_func *f, void *arg)
1158 {
1159         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1160
1161         if (ss->ss_ops != NULL)
1162                 ss->ss_ops->scan_iterate(ss, f, arg);
1163 }
1164
1165 /*
1166  * Flush the contents of the scan cache.
1167  */
1168 void
1169 ieee80211_scan_flush(struct ieee80211vap *vap)
1170 {
1171         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1172
1173         if (ss->ss_ops != NULL && ss->ss_vap == vap) {
1174                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
1175                 ss->ss_ops->scan_flush(ss);
1176         }
1177 }
1178
1179 /*
1180  * Check the scan cache for an ap/channel to use; if that
1181  * fails then kick off a new scan.
1182  */
1183 struct ieee80211_channel *
1184 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
1185 {
1186         struct ieee80211_scan_state *ss = ic->ic_scan;
1187
1188         if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
1189                 /* XXX printf? */
1190                 return NULL;
1191         }
1192         if (ss->ss_ops->scan_pickchan == NULL) {
1193                 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
1194                     "%s: scan module does not support picking a channel, "
1195                     "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
1196                 return NULL;
1197         }
1198         return ss->ss_ops->scan_pickchan(ss, flags);
1199 }